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TEE  HOME   CYCLOPEDIA 


CYCLOPEDIA 


OF 


THE   USEFUL   ARTS; 


INCLUDING 

AGRICULTURE,  ARCHITECTURE,  DOMESTIC  ECONOMY,  ENGIN  BERING, 

MACHINERY,  MANUFACTURES,  MINING,  PHOTOGENIC 

AND  TELEGRAPHIC  ART: 


AN   EXPOSITION    OF  THEIR  PRINCIPLES   AND   PRACTICE  AND    A   COMPEND    OF 
AMERICAN    AND    EUROPEAN    INVENTION. 


BY 

T.  ANTISELL,  M.  D, 


NEW   YORK: 
A.  S.  BARNES  &  CO.,  51  JOHN-STREET 

CINCINNATI :— H.  W.  DERBY  &  CO. 
1855. 


Entered  according  to  Act  of  Congress  in  the  year  1854, 

By   A.  S.  BARNES    &   CO., 

In  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for  the  Southern 
District  of  New  Yorjs. 


PREFACE. 


The  aim  and  scope  of  this  volume  is  perhaps  sufficiently  indicated 
in  the  title-page.  It  is  intended  to  comprise,  in  a  clear  and  com- 
prehensive form  for  popular  reference,  a  dictionary  of  all  terms  used 
in  the  application  of  science  to  the  useful  arts.  It  is  believed  that 
a  manual  of  this  kind — sufficiently  full  in  its  details  for  ordinary 
purposes,  and  accurately  posted  up  to  the  present  time,  yet  in  a 
comparatively  moderate  compass — will  meet  a  very  important  want 
in  this  country,  which  is  yet  unfilled  by  the  larger  and  more  expen- 
sive works  already  before  the  public. 

The  number  of  new  inventions  of  various  sorts  constantly 
brought  forward  in  the  United  States  is  so  enormous,  and  the  propor- 
tion of  those  which  prove  really  valuable  is  so  small,  that  it  would  be 
needless  in  a  volume  like  this  to  attempt  any  thing  more  than  a 
reference  to  the  most  important  and  established  improvements.  The 
number  of  applications  for  patents  in  the  year  1849  was  1955, — 
of  which  1066  were  granted.  The  editor  of  this  volume  has  endea- 
vored to  condense  in  its  pages  as  much  practical  information  as  the 
limits  of  the  work  would  admit,  from  various  recent  sources,  such 
as  the  reports  of  the  Patent  Office,  and  the  scientific  periodicals,  as 
well  as  from  the  standard  works  of  Brande  and  Ure.  He  has,  in 
short,  combined  the  best  foreign  information  at  present  accessible 


11  PREFACE. 

with  the  latest  details  of  the  progress  of  the  Useful  Arts  in  the 
United  States. 

In  some  fewjnstances,  this  work  contains  topics  which  are  also 
treated  of  in  the  other  volumes  of  the  series  :  but  in  this  volume 
practical  details  are  given,  while  the  others  are  intended  to  give 
merely  the  scientific  definitions 

It  is  not  to  be  supposed  that  infallibility  is  claimed  for  a  com- 
pilation of  this  kind.  Every  care  has  been  used  to  secure  accuracy, 
but  the  publisher  will  still  be  glad  to  avail  himself,  in  future  edi- 
tions, of  all  useful  suggestions  and  corrections  with  which  he  may 
be  favored. 


CYCLOPEDIA 


THE   USEFUL   ARTS 


ACETATE.  A  saline  compound 
formed  by  the  union  of  an  alkali,  or  an 
earth  with  Acetic  Acid. 

ACETIC  ACID.  The  sour  principle 
of  vinegar.  This  acid  occurs  in  the  vege- 
table kingdom  in  the  elder  and  some 
varieties  of  rhus.  It  exists  in  the  gas- 
tric juice  and  other  animal  secretions. 
When  vegetable  matter  is  distilled  in 
close  vessels,  this  acid  is  always  one  of 
the  products.  Alcoholic  liquids  are  ca- 
pable of  producing  acetic  acid,  and  it  is 
the  last  stage  in  the  fermentation  of  many 
vegetable  bodies  containing  starch  or  su- 
gar— as  paste,  &c.  Pyroligneous  acid  is 
acetic  acid  derived  from  wood — for  the 
manufacture  of  which  see  under  that 
head.  The  purest  acetic  acid  is  that 
made  by  the  oxydation  of  alcohol.  The 
oxydation  is  produced  by  the  action  of 
the  atmosphere.  In  Germany,  where 
this  process  was  first  adopted,  "the  alco- 
hol was  exposed  in  very  large  surface 
to  the  action  by  being  made  to  trickle 
along  the  shavings  of  wood.  These  were 
placed  in  a  deep  barrel,  perforated  at  the 
sides  with  a  number  of  holes  so  that  free 
access  of  air  to  the  inside  of  the  vessel 
was  effected ;  on  the  upper  part  of  the 
barrel  was  a  raised  rim  capable  of  hold- 
ing a  certain  head  of  alcohol,  and  the  up- 
per end  of  the  barrel  was  perforated  with 
a  few  fine  apertures  so  that  the  alcohol 
might  slowly  stream  down  on  the  shav- 
ings; it  was  thus  exposed  to  a  large 
quantity  of  air  constantly  renewed,  and 
by  the  time  it  reached  the  bottom  of  the 
vessel  it  was  converted  into  vinegar,  or 
dilute  acetic  acid.  It  was  drawn  off  by 
a  cork  from  the  lower  part  of  the  barrel, 
placed  in  a  still  and  distilled  with  a  gen- 
tle heat ;  the  portions  which  come  over 
first,  contain  the  acetic  acid. 

A  great  improvement  on  this  process 


has  been  the  substitution  of  spongy  pla- 
tinum (see  Platinum)  for  the  wood  shav- 
ings. The  principle  in  both  is  the  same, 
being  the  oxydation  of  alcohol  by  the 
air.  Into  a  large  case  of  wood  with 
glass  sides  or  windows  for  observing  the 
process,  and  fitted  with  shelves  within  a 
few  inches  of  each  other,  is  placed  a 
number  of  saucers  filled  with  the  alco- 
hol, and  over  each  saucer  is  suspended 
a  small  portion  of  the  black  platinum 
powder.  The  quantity  of  alcohol  in  the 
saucers  varies  with  the  dimensions  of 
the  case ;  100  cubic  inches  of  air  being 
capable  of  oxydizing  11  grains  of  abso- 
lute alcohol,  and  converting  it  into  12*2 
of  absolute  acetic  acid  and  6s  grains 
of  water.  The  case  must  now  be  warm- 
ed up  to  80°  Fahr.  by  solar  or  arti- 
ficial heat  and  the  alcohol  induced  to 
evaporate  off  the  saucers  by  some  lead- 
ing points,  as  strings  or  folds  of  paper 
set  endways  in  the  liquid :  in  a  short 
time  the  temperature  inside  the  box 
rises  ;  vapors  form,  condense  on  the  in- 
side, and  roll  down  to  the  bottom.  This 
process  continues  so  long  as  there  is  any 
oxygen  of  the  air  in  the  vessel  uncon- 
sumed :  now  and  then  fresh  supplies  of 
air  are  needed — 8  oz.  of  the  platinum 
powder  will  in  a  day's  work  convert  one 
pound  of  alcohol  into  acetic  acid.  The 
change  arises  from  the  absorption  of  oxy- 
gen from  the  air,  and  its  union  with  the 
elements  of  alcohol,  which  results  in  the 
formation  of  acetic  acid  and  water.  By 
the  chemist  the  change  is  expressed  by 
the  formula :  alcohol  C*  H«  0«  -f-  0<  from 
air  =  C*  H3  O3  acetic  acid  -j-  3  H  0  wa- 
ter. Hence  100  parts  of  alcohol  absorb 
nearly  69  parts  of  oxygen,  and  there  are 
produced  nearly  111  parts  of  acetic  acid 
and  58  parts  of  water.  Strong  acetic  acid 
is  also  made  by  distilling  crystalled  bin- 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[adz 


acetate  copper  (verdigris)  in  close  ves- 
sels at  a  high  heat.  It  can  also  be  made 
by  distilling  acetate  of  potass  and  acetate 
of  lead  (sugar  of  lead)  with  oil  of  vitriol. 
In  its  purest  state  it  is  united  with  an 
atom  of  water,  and  has  a  specific  gravity 
of  1 '063.  It  is  caustic  on  the  tongue  and 
to  the  skin :  it  is  used  as  a  scent,  and 
when  essential  oils  are  added,  constitutes 
the  aromatic  vinegar.  It  dissolves  cam- 
phor, gluten,  resins,  gum  resins,  fibrine, 
and  albumen. 

ACETONE.  A  term  for  pyro-acetic 
spirit. 

ACIDS.  A  class  of  chemical  substances 
remarkable  for  their  sour  taste  and  their 
readiness  to  unite  with  alkalies  and  earths 
to  form  salts :  there  are  many  hundred 
acids,  distributed  in  the  three  kingdoms 
of  nature.  With  one  exception  they  red- 
den vegetable  blue  colors,  as  blue  cabbage 
and  litmus.  Some  exist  naturally  in  the 
mineral,  animal,  and  vegetable  world, 
and  some  are  the  result  of  chemical  pro- 
cesses :  a  few  are  solid  bodies  and  some 
gaseous,  but  the  greater  number  are  in 
the  liquid  form. 

ACTINOLITE.  A  hornblend  mineral 
of  a  green  tint,  and  crystallized  in  slender 
needle  prisms! 

ADIPOC1RE.  The  change  which  flesh 
undergoes  after  death  when  placed  in 
circumstances  where  putrefaction  does 
not  proceed  in  the  ordinary  way.  In 
Paris,  when  in  the  latter  quarter  of  the 
last  century  the  dead  bodies  were  re- 
moved from  the  Innocents  to  the  Cata- 
combs, those  which  lay  in  a  pit — to  the 
number  of  1500,  in  coffins  packed  close 
together — had  their  flesh  converted  into 
a  white  fatty  soap  :  it  resembled  sperma- 
citi,  and  was  named  adipocire  by  Four- 
croy.  Chevreul  found  it  to  be  made  up 
of  fatty  acids.  Moisture  appears  to  be 
necessary  to  produce  this  substance,  as  it 
is  not  produced  in  dry  earth :  and  it  is 
very  doubtful  if  it  be  formed  from  the 
muscle  of  man,  but  rather  some  altera- 
tion of  the  fat  actually  existing  in  the 
body  at  the  time  of  death. 

ADULAEIA.    A  variety  of  felspar. 

AFFINITY.  A  term  denoting  the  force 
of  chemical  attraction  by  which  dissimi- 
lar bodies  are  brought  into  union  and 
retained  so.  It  is  distinguished  from 
cohesion,  which  is  exerted  between  bodies 
of  a  similar  nature.  Cohesion  is  a  force 
antagonistic  to  affinity,  and  for  two  dis- 
similar substances  to"  unite  it  is  neces- 
sary that  one  of  them  should  be  fluid : 
if  both  be  fluid,  affinity  comes  into  play 
more  readily,  as  in  the  case  of  alloys : 


dissolving  the  substances  in  some  special 
liquid,  or  heating  them  until  melted,  are 
the  modes  of  bringing  the  particles  of 
matter  sufficiently  close  to  form  chem- 
cal  union.  Every  process  of  chemical 
manufactures  implies  the  union  and  de- 
composition of  bodies,  which  are  effected 
by  calling  into  play  their  affinities.  Many 
bodies,  although  dissimilar,  have  no  ten- 
dency to  unite — as  oil  and.  water,  mer- 
cury and  water,  mercury  and  oil.  This 
is  explained  by  saying  that  these  bodies 
have  no  affinity  for  one  another:  while 
alcohol  and  water,  sulphuric  acid  and 
potass,  oxalic  acid  and  lime,  unite  readily 
because  their  mutual  affinities  are  strong. 

ADHESION.  That  property  possessed 
by  bodies  of  dissimilar  natures  of  resist- 
ing a  force  applied  to  separate  them  ; 
and  it  differs  from  cohesion  and  affinity. 
Adhesion  cannot  occur  between  two  solid 
bodies,  for  then  the  force  which  binds 
them  together  is  either  some  modifica- 
tion of  the  attractive  force,  or  it  is  due  to 
atmospheric  pressure :  for  perfect  adhe- 
sion, one  of  the  bodies  ought  to  be  fluid 
or  semifluid  ;  it  may  afterwards  return  to 
the  solid  condition  without  destroying 
the  adhesion,  unless  it  crystallize.  It  is 
desirable  also  that  they  should  not  con- 
tract unequally  in  cooling,  for  then  the 
adhesion  would  be  destroyed  :  for  the 
union  of  two  surfaces  into  one  it  is  there- 
fore necessary  that  both  should  contract 
equally  :  and  cement  for  uniting  different 
surfaces  depends  for  its  fitness  upon  this 
property:  to  cement  metals  with  other 
solids,  solders  are  needful,  and  particular 
solders  for  various  metals.  Such  bodies 
as  pitch,  which  even  at  reduced  tempera- 
tures will  expand,  are  those  which  ad- 
here most  firmly.  The  adhesion  between 
solid  bodies  is  sufficiently  strong  to  over- 
come the  cohesive  force  of  one  of  them — 
as  when  two  pieces  of  wood  are  glued 
together  and  then  separated  forcibly,  a 
layer  of  glue  remains  on  each  piece.  The 
adhesion  of  the  wafer  on  the  envelope  is 
greater  than  the  cohesion  between  the 
particles  of  the  paper,  and  a  layer  comes 
off  on  the  surface  of  the  wafer  when  the 
latter  is  separated.  When  a  solid  dips 
in  a  liquid,  its  adhesion  is  sometimes 
greater  than  the  cohesion  for  the  parti- 
cles of  the  liquid,  as  when  wood  or  metal 
is  dipped  into  water :  the  water  adhering 
is  said  to  wet  it.  Wood  or  the  finger, 
dipped  into  quicksilver,  is  not  wetted.  Oils 
have  no  adhesion  for  water.  (For  other 
instances  of  adhesion,  see  Cement.) 

ADZE — Addice.  A  cutting  chisel  with 
an  arched  blade  and  the  edge  at  right 


'] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


3 


angles  to  the  handle :  it  differs  from  | 
the  chisel  in  application,  the  force  "being 
impact  and  arising  from  a  blow  and  not 
that  of  mere  pressure.  The  adze  cuts 
the  wood,  if  its  edge  be  fine  ;  but  if  not, 
the  wood  is  split  and  the  tool  acts  then 
more  like  the  axe  as  a  wedge  than  the 
chisel.  In  coarse  preparatory  work,  the 
adze  is  carried  through  the  space  be- 
tween the  workman  two  feet,  and  the 
quantity  of  wood  removed  is  very  great ; 
in  fine  work,  the  foot  is  placed  upon  the 
wood  and  the  adze  is  carried  two  or  three 
inches  under  the  sole,  and  the  smooth- 
ness and  delicacy  of  the  work  accom- 
plished is  surprising. 

AER  ATEDW  ATERS.  Artificial  drinks 
impregnated  with  carbonic  acid — as  soda 
water,  ginger  beer,  carrara  water,  &c. 

AGARIC.  A  species  of  fungus  or  puff- 
ball  ;  occasionally  used  as  a  tinder  and  as 
a  black  dye  in  combination  with  per-salts 
of  iron. 

AGATE.  A  name  given  to  many  com- 
binations of  chalcedony,  carnelian,  quartz, 
amethyst  and  flint.  It  is  one  of  the  varied 
forms  of  silicious  minerals,  and  contains 
98  per  cent,  of  silica ;  it  is  opaque,  and 
has  a  resinous  fracture  with  deep  tints, 
produced  by  traces  of  iron.  when  a 
section  is  made  it  displays  a  series  of  dark 
lines  or  bands,  sometimes  irregular,  some- 
times rounded,  which  are  the  edges  of 
successive  deposits  made  by  the  mineral 
during  its  formation.  Agates  take  a  high 
polish",  and  are  much  valued  as  ornamen- 
tal stones  in  the  manufacture  of  cups, 
rings,  seals,  knife-handles,  snuff-boxes, 
&c. ;  hurnishers  are  made  of  agate  for 
the  use  of  bookbinders  and  silversmiths. 
These  gems  occur  naturally  in  amygdaloid 
trap  rocks,  lying  in  nodules,  surrounded 
by  chloritic  clay,  also  in  beds  of  streams 
and  rivers,  where  they  have  been  washed 
down.  They  are  made  darker  in  tint  by 
being  boiled"  in  oil,  and  then  dipped  in 
oil  of  vitriol.  The  carnelian  is  an  agate 
of  a  flesh  red  or  yellow  tint :  it  is  com- 
mon in  the  sandy  plains  f  Africa,  India, 
and  Asia  Minor. 

AIR.  The  gaseous  envelope  of  the  earth. 
Our  planet  has  two  coverings:  one  the 
water  which  is  distributed  as  lakes  and 
seas,  filling  up  the  deep  cavities  of  the 
solid  surface,  tending  to  produce  a  more 
level  superficies  ;  the  second  covering  is 
the  air  or  atmosphere  which  rests  upon 
the  top  of  the  water  and  the  dry  land, 
enveloping  the  highest  mountains,  and 
rising  upwards  to  an  altitude  somewhat 
above  45  miles  ;  it  is  a  true  aeriform  ocean 
surrounding  our  earth,  and  has  upon  its 


upper  surface  waves  and  tides;  and 
throughout  its  mass,  currents  flowing  in 
constant  and  variable  directions,  precisely 
as  those  of  the  ocean  comport  themselves ; 
it  is  held  down  to  the  surface  of  the  earth 
by  attraction,  and  rotates  with  the  planet ; 
its  density  varies  with  its  actual  height  at 
the  place  of  observation,  of  whicn  the 
barometric  pressure  is  the  evidence.  This 
pressure  diminishes  as  the  elevation 
above  the  sea  increases,  owing  to  the  up- 
per portions  of  the  atmosphere  pressing 
upon  and  condensing  the  lower  strata  so 
much  so,  that  one-half  the  actual  weight 
of  the  atmosphere  is  comprised  within 
the  space  of  the  lower  5  miles  of  its 
total  height,  the  remaining  40  miles  in 
height  containing  the  other  half.  The 
air  is  highly  compressible  and  clastic,  and 
its  volume  diminished  inversely  as  the 
pressure  increases.  This  accounts  for  the 
facility  of  setting  it  in  motion  and  its  ve- 
locity. Like  fluids,  it  presses  equally  in 
every  direction,  and  when  it  comes  in 
contact  with  a  more  expanded,  and  there- 
fore lighter  portion  of  air,  it  pushes  it  up 
and  occupies  its  place,  producing  currents 
of  air  and  winds  when  it  flows  in  streams, 
and  sound  when  it  is  thrown  into  vibra- 
tions or  undulations.  The  air  is  warmed 
solely  by  the  earth,  and  not  by  the  trans- 
mitted rays  of  the  sun, — hence  warm  air 
exists  within  the  tropics,  and  diminishes 
toward  the  poles,  and  sensibly  decreases 
every  350  feet  of  elevation.  Air  was  ono 
of  the  simple  substances  of  the  ancient 

Shilosophers  ;  but  it  has  been  shown  by 
cheele  and  Cavendish  to  be  a  compound 
body  made  up  of  oxygen  gas  and  nitro- 
gen. The  proportions  in  which  they  are 
found  to  exist,  are  21  of  oxygen  and  79  of 
nitrogen  by  volume  in  100  parts.  These 
substances  are  not  chemically  united, 
they  are  merely  mixed  together.  There 
is  also  contained  in  the  atmosphere  a 
small  quantity  of  carbonic  acid,  amount- 
ing to  one  twenty-five  hundredth  part, 
winch,  no  matter  at  what  elevation  the  air 
may  be  drawn,  is  still  found.  Saussure 
detected  it  at  Mont  Blanc,  and  Boussin- 
gault  on  the  Andes,  so  that  it  is  a  regular 
constituent.  Liebig  has  shown  that  am- 
monia can  also  be  detected  in  the  atmos- 
phere, to  which  may  be  added  a  variable 
quantity  of  watery  vapor,  odors  of  plants, 
and  other  volatile  substances ;  it  no 
doubt  also  contains  floating  particles 
(miasmata),  during  periods  of  epidemic 
disease.  The  chemical  properties  and 
the  beneficial  effects  of  the  air  are  due  to 
the  pressure  of  oxygen,  the  removal  of 
which,  or  any  alteration  of  its  amount 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ALA 


and  condition,  renders  the  air  injurious 
to  life.  (See  Ventilation.)  Although  air 
is  invisible,  and  much  lighter  than  solid 
or  fluid  bodies,  yet  it  is  still  subject  to  all 
the  physical  laws  which  govern  gases  ;  in 
a  large  quantity,  as  when  the  sky  is  clear, 
it  gives  us  a  blue  tint  to  the  eye,  which 
may  be  due  to  the  vapor  of  Avater  in  the 
atmosphere  refracting  the  light.  It  occu- 
pies a  given  space,  and  is  impenetrable, 
and  no  other  substance  can  occupy  where 
it  is  except  it  be  by  displacement.  It  is  ca- 
pable of  communicating  weight :  and  100 
cubic  inches  of  it  are  found  to  weigh 
31-0117  grains  at  the  temperature  of  60°, 
and  the  barometric  column  standing  at 
30°.  This  weight  is  equal,  on  the  whole 
atmosphere  of  45  miles  height,  to  a  pres- 
sure of  15  lbs.  on  every  square  inch. 
This  pressure  varies  in  different  places 
and  at  different  times.  {See  Barometer.) 
This  pressure  is  exerted  upon  every  sub- 
stance at  the  level  of  the  sea.  Air  may 
be  compressed  into  a  smaller  volume,  in 
proportion  to  the  pressure  exerted  upon. 
Doubling  the  pressure  condenses  the  air 
into  one-half  its  bulk;  when  released 
from  pressure  it  expands  to  its  original 
bulk :  this  is  due  to  its  elasticity,  which, 
like  all  gases,  is  very  great. 

A 1 R-P  U  M  P — Exhausting  Syringe. 
Instruments  founded  upon  the  elastic 
property  of  the  air.  The  syringe  consists 
of  a  brass  cylinder  with  an  air-tight  piston ; 
a  valve  at  the  top  opens  upwards  into  the 
body,  and  one  at  the  lower  part  opens 
outward  (at  the  side)  into  the  external 
air.  This  apparatus  is  screwed  on  to  any 
vessel  which  requires  to  have  the  air  re- 
moved. On  raising  the  piston  the  air 
from  the  vessel  below  follows  it  upward, 
filling  the  cylinder ;  if  the  lower  stopcock 
be  now  closed,  and  the  cylinder  pressed 
down,  the  air  will  escape  by  the  valve  at 
the  side,  and  the  cylinder  can  be  emptied 
in  this  way.  By  constant  repetitions  of 
raising  the  piston,  and  then  expelling  the 
contained  air  of  the  cylinder,  the  greater 
part  of  the  air  of  the  attached  vessel  is 
drawn  up  and  removed.  The  whole  air 
cannot  be  discharged  in  this  way :  for 
after  it  has  been  worked  some  time,  and 
the  greater  quantity  of  air  discharged, 
the  elastic  force  of  the  remainder  is  so 
slight  as  not  to  be  able  to  raise  the  valve. 
The  air-pump  is  a  doubly  exhausting 
syringe,  which  has  its  valves  in  the  pis- 
ton or  plug.  There  are  two  moving  in 
the  cylinder  or  barrels,  with  a  reciprocat- 
ing motion  communicated  by  a  toothed 
wheel  and  racked  piston  rods.  The  bar- 
rels communicate  by  means  of  a  tube  with 


a  table  of  metal,  upon  which  is  fixed  a 
bell-glass  or  receiver,  made  stoutly,  and 
with  a  strong  rim  at  the  bottom  ground 
finely,  so  as  to  fit  smooth  on  the  table  ;  a 
a  little  tallow  or  fat  is  used  to  smear  the 
table  to  make  the  fitting  more  tight.  The 
receiver  is  thus  a  transparent  air-tight 
chamber  in  which  any  object  may  be 
placed  from  which  it  is  needful  to  remove 
air.  A  stopcock  is  fitted  to  the  connect- 
ing tube,  to  shut  off  or  let  on  external  air 
when  desired.  To  good  air-pumps  a 
mercurial  gauge  is  attached. 

AIR-BEDS.  Another  application  of 
the  elasticity  of  the  air  to  supply  the 
padding  or  stuffing  material  of  pillows, 
cushions,  and  beds,  by  the  use  of  air,  in- 
stead of  solid  substances  :  a  bag  of  cloth 
is  rendered  air-proof  by  means  of  a  var- 
nish of  India-rubber  or  gutta  percha,  a 
tube  and  stopcock  are  affixed  to  one  cor- 
ner, through  which  the  air  is  blown  in  to 
inflate  the  bag.  When  moderately  dis- 
tended with  air  these  beds  and  cushions 
are  tolerably  soft.  The  objection  to  these 
is  that  they  warm  too  soon — the  heat  of 
the  body  accumulates  in  the  pillow,  the 
air  of  Which  is  a  non-conductor. 

AIR-GUNS  are  syringes  used  for  con- 
densing air,  acting  somewhat  similarly  to 
the  exhausting  syringe.  In  the  air-gun 
the  vessel  for"  holding  the  air  is  a  small 
metal  ball,  having  a  small  hole  and  valve 
turned  inwards.  The  ball  is  screwed  on 
to  a  barrel  fitted  with  a  bullet,  when  upon 
turning  a  cock,  communicating  between 
the  condensed  air  and  the  bullet,  the  lat- 
ter is  driven  out  with  great  velocity.  To 
condense  the  air  requires  the  syringe  to 
act  in  the  reverse  manner  to  that  used 
for  exhaustion. 

ALABASTER.  A  term  sometimes  ap- 
plied to  stalactitic  carbonate  of  lime.  By 
the  ancients  was  understood  small  white 
stone  vessels  of  a  peculiar  form,  made  at 
Alabastron  in  Egypt ;  it  is  now  generally 
applied  to  that  variety  of  sulphate  of 
lime,  known  as  granular  gypsum,  used 
for  carving  small  statues,  groups  of 
figures  and  animals,  and  boxes  and  vases, 
which  are  turned  in  a  lathe.  For  these 
purposes  it  is  well  adapted  by  its  white- 
ness, translucency  and  softness.  The 
best  is  quarried  near  Volterrain  Tuscany. 
In  this  duchy  are  the  hot  springs  of  San 
Filippo,  where  the  water,  almost  boiling, 
contains  in  solution  a  large  quantity  of 
carbonate  of  lime,  held  dissolved  by  sul- 
phureted  hydrogen,  which  escapes  as 
soon  as  the  water  is  exposed  to  tlie  air. 
Advantage  is  taken  of  this  property  to 
make  bas-reliefs  of  much  hardness,  by 


alk] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


placing  moulds  of  sulphur  obliquely  in 
wooden  tubs,  open  at  the  bottom.  The 
water  of  the  spring,  after  depositing  its 
turbid  matter,  is  conveyed  above  those 
tubs,  which  have  affixed  to  their  top 
wooden  cross-pieces,  the  water  is  allowed 
to  fall  upon  them,  and  is  then  poured  in 
fine  streams  over  the  moulds  hanging  be- 
low. From  two  to  four  months  are  re- 
quired for  obtaining  castings. 

ALCARAZZAS.  A  species  of  porous 
earthenware  used  in  Spain  for  cooling 
liquors. 

ALBUMEN.  The  white  portion  of  the 
egg  is  in  great  part  albumen.  It  is  also  a 
constituent  of  the  fluid  portion  of  the 
blood,  and  of  the  sap  of  some  plants,  as 
potato,  parsnip,  carrot,  in  the  seeds  ol 
the  cereals,  and  in  most  nuts.  The  cha- 
racteristic property  of  albumen,  under 
any  circumstance,  is  its  coagulating  at  a 
temperature  about  160°  Fahr.  When 
pure,  vegetable  and  animal  albumen  are 
the  same  substance.  That  from  the  egg 
soon  putrefies  in  the  air ;  but  if  it  be 
spread  out  in  thin  films,  it  dries  readily, 
and  may  then  be  preserved  unaltered  for 
any  length  of  time.  Once  coagulated, 
albumen  will  not  dissolve  again  in  wa- 
ter, but  is  soluble  in  caustic  alkalies. 
The  solidification  of  albumen  is  believed 
to  be  due  to  the  loss  of  alkali,  dissolved 
out  by  the  boiling  water.  From  having 
this  property,  albumen  is  used  to  clarify 
syrups,  coffee,  &c.  It  is  also  coagulated 
by  alcohol,  the  majority  of  acids,  except 
the  acetic,  which  dissolves  it,  and  by  a 
few  metallic  salts,  such  as  corrosive 
sublimate,  for  which  it  is  an  antidote. 
Lime,  baryta,  and  strontia,  form  com- 
pounds with  albumen,  which  harden  in 
drying,  and  become  good  lutes  or  cements 
for  china  or  glass,  or  spread  on  paper  for 
chemical  apparatus. 

ALCOHOL.  The  liquor  procured  by 
distillation  of  vegetable  infusions  of  a 
saccharine  nature,  and  juices  which  have 
passed  through  the  vinous  fermentation. 
Ordinary  alcohol  is  not  pure,  containing 
usually  half  its  weight  of  water,  from 
which  it  may  be  freed  by  redistillation  at 
a  gentle  steam  or  water-bath  heat,  until 
its  specific  gravity  is  -880.  To  free  it  per- 
fectly, it  is  necessary  to  add  into  the  still, 
or  retort,  caustic  lime,  calcined  pearl- 
ashes,  or  fused  chloride  calcium ;  it  is 
then  perfectly  free  from  water,  and  has 
a  specific  gravity  of  -793  ;  it  then  boils  at 
169°  Fahr.  Alcohol  may  also  be  concen- 
trated by  exposing  it  in  ox  bladders,  ow- 
ing to  the  property  which  the  latter 
possess,  of  allowing  water  to  pass  through 


the  pores  and  evaporate  out,  but  giv- 
ing little  or  no  facility  for  the  vapor 
of  alcohol  to  escape.  Both  surfaces 
of  the  bladder  should  be  soaked  in  wa- 
ter, and  freed  from  fat  and  minute  ves- 
sels adhering  on  both  the  outer  and 
inner  surfaces ;  it  then  should  get  a 
couple  of  coats  of  a  solution  of  isin- 
glass on  the  outer,  and  double  the  number 
on  the  inside  surface  ;  the  spirit  is  then 

Eoured  in,  but  the  bladder  not  quite  filled 
y  it,  a  portion  of  air  occupying  the  top  : 
it  is  then  tied  tightly  at  the  mouth,  and 
hung  in  a  warm  place  near  a  stove  or  oven. 
In  this  way  alcohol  may  be  concentrated 
in  twelve  hours,  and  this  kind  is  well 
adapted  for  varnishes.  Alcohol  has  a 
great  attraction  for  water,  and  if  left  ex- 
posed, rapidly  attracts  moisture  from  the 
air:  it  should  therefore  be  kept  in  well 
closed  vessels.  From  this  property  it  is 
well  adapted  for  preserving  anatomical 
specimens.  It  has  the  property  of  dis- 
solving many  substances,  as  soap,  cam- 
phor, resins,  essential  oils,  castor  oil, 
forming  varnishes,  essences,  perfumes, 
and  extracts.  If  these  solutions  be  mixed 
with  water,  milkiness  or  opacity  is  pro- 
duced, owing  to  the  alcohol  separating 
these  substances,  by  preferring  to  unite 
with  the  water.  The  strength  of  alcohol 
is  determined  by  instruments  which  read 
off*  its  specific  gravity,  calculated  tables 
for  which  may  be  found  in  more  techni- 
cal works.  The  instruments  are  termed 
alcoholmeters,  hydrometers.  Gay-Lus- 
sac's  instrument,  the  "  alcoometre,"  is 
probably  the  instrument  yielding  the 
most  correct  results :  absolute  alcohol 
consists  chemically  of  4  atoms  of  carbon, 
6  of  hydrogen,  and  2  of  oxygen. 

ALE.  Infusion  of  barley  and  infusion 
of  hops,  fermented  together. 

ALEMBIC.  A  vessel  used  in  distilla- 
tion, for  receiving  the  liquid  to  be  dis- 
tilled. 

ALEMBROTH  SAL.  An  old  term  for 
white  precipitate  of  mercury,  or  the  dou- 
ble chloride  of  mercury  and  ammonia. 

ALIZARINE.  One  of  the  principles  of 
the  madder  plant :  from  which  it  may 
be  obtained  by  charring  the  powder  root 
with  oil  of  vitriol,  washing  the  black 
mass  well  with  water,  drying  and  heat- 
ing, when  alizarine  is  obta'ined  in  crystals 
of  an  orange-red  color. 

ALKALI.  A  name  first  applied  by  the 
Arabians  to  the  carbonates  of  soda  and 
potash  derived  from  the  ashes  of  plants, 
but  now  extended  to  those  substances 
which  dissolve  in  water,  generally  form 
soaps  with  oils,  and  neutralize  acids  form- 


6 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[alr 


ing  crystalline  salts.  The  chief  alkalies  of 
importance  in  the  arts  are  potash,  soda, 
ammonia,  and  qninia.  They  have  a  com- 
mon effect  upon  some  colors — such  as 
turning  the  red  colors  of  roses,  cabbages, 
and  radishes  to  green,  the  red  of  litmus  to 
purple,  and  the  yellow  of  turmeric  and  a 
few  other  vegetable  dyes  to  brown.  Even 
when  these  three  first  named  alkalies  are 
united  with  carbonic  acid,  they  exert  the 
same  reaction,  by  which  they  are  readily 
distinguished  from  lime  and  magnesia. 
When  pure  they  have  an  acrid  and  urin- 
ous taste,  dissolve  animal  matter  readily, 
and  unite  with  oils  :  they  also  unite  with 
water  in  airy  proportion.  A  strong  solu- 
tion in  water  is  termed  a  lye  or  ley. 

ALKALIMETER.  An  instrument  used 
for  testing  the  strength  of  the  alkalies  of 
commerce.  The  operation  is  termed  al- 
kalimetry, the  general  principle  of  which 
consists  in  ascertaining  the  quantity  of 
real  alkali  in  a  given  weight  of  the  sub- 
stance examined,  by  finding  how  much 
of  the  latter  is  required  to  neutralize  a 
known  quantity  of  an  acid — as  sulphuric 
acid.  The  first  step  is  to  prepare  a  stock 
of  dilute  sulphuric  acid  ot  a  known 
strength,  containing  for  example,  100 
grains  of  real  acid  in  every  1000  grain 
measures  of  liquid.  A  large  quantity — as 
a  gallon  or  more — may  be  prepared  at 
once :  thus,  the  oil  of  vitriol,  if  it  be  good 
and  of  the  specific  gravity  of  1-85,  con- 
tains in  every  49  grains  40  grains  of  ab- 
solute acid.  For  the  proportion  required 
above — every  gallon  or  70,000  grains  of 
dilute  acid — 7000  grains  of  real  or  abso- 
lute acid  is  demanded ;  this,  at  the  com- 
position of  the  acid  given,  is  equal  to 
8571  grains  of  common  oil  of  vitriol.  All 
that  is  required,  is  then  to  weigh  out 
8571  grains  of  vitriol  and  dilute  it  with 
water  until  when  cool  the  mixture  shall 
measure  exactly  one  gallon. 

The  "  Alkalimeter"  is  next  to  be  con- 
structed out  of  a  piece  of  even  cylindri- 
cal glass  tube,  fifteen  inches  long  and 
six-tenths  of  an  inch  wide  internally, 
closed  at  one  end  and  moulded  into  a 
spout  or  lip  at  the  other  ;  a  strip  of  paper 
is  pasted  on  the  tube  and  suffered  to  dry, 
after  which  it  is  graduated  by  counter- 
poising it  in  a  nearly  upright  position  in 
the  pan  of  a  delicate  balance,  and  weigh- 
ing into  it  successively  one,  two,  and 
three  hundred  grains  of  distilled  water 
at  60°  until  the  whole  quantity  of  1000 
grains  be  reached,  the  level  of  the  tube 
after  each  addition  being  carefully  marked 
with  a  pen  upon  the  strip  of  paper  while 
the  tube  is  neld  quite  upright  and  the 


mark  made  between  the  top  and  bottom 
of  the  curve  formed  by  the  surface  of 
the  water.  The  smaller  divisions  of  each 
hundred  parts  may  then  be  made  with 
the  compass  into  tenth  parts.  The  gra- 
duation oeing  accurate  and  complete,  the 
operator  may  transfer  the  marking  to  the 
glass  by  means  of  a  file,  and  the  paper 
may  be  removed  with  hot  water.  The 
numbers  can  be  scratched  with  the  hard 
end  of  the  file.  When  this  instrument 
is  used  with  the  dilute  acid  above,  every 
division  of  the  glass  will  correspond  to 
one  grain  of  real  acid. 

The  alkali  is  examined  thus  :  50  grains 
of  the  sample  are  weighed,  dissolved  in 
warm  water,  and  if  needful,  filtered :  the 
alkalimeter  is  then  filled  to  the  top  of  the 
scale  with  the  dilute  acid,  and  the  latter 
poured  from  it  into  the  alkaline  solution, 
which  is  tried  from  time  to  time  with 
red  litmus  paper.  When  the  solution, 
after  being  heated  a  few  minutes,  no 
longer  affects  either  blue  or  red  litmus, 
the  measure  of  liquid  employed  is  read 
off,  and  the  quantity  of  soda  or  potass 
present  in  the  state  of  carbonate  or  hy- 
drate in  the  50  grains  of  salt,  is  found  by 
the  rule  of  proportion.  Suppose  soda 
was  the  alkali,  and  that  33  measures  of 
acid  had  been  used ;  then  by  taking  their 
atomic  proportions  in  which  the  acid  and 
soda  unite,  it  would  stand  thus :  as 

Sulph.  acid  40  :  soda  31-9  :  :  33  :  25-6 
in  50  grains.  The  sample  therefore  con- 
tains 51-2  per  cent,  of  available  alkali. 
The  quantity  of  alkali  in  a  carbonated 
form  may  be  known  bv  weighing  the 
body  before  and  after  the  expulsion  of 
carbonic  acid ;  from  the  loss  may  be  cal- 
culated the  per  centage  of  alkali.  By  the 
use  of  Fresenius's  apparatus  for  this  pur- 
pose, the  precision  attained  leaves  no- 
thing to  be  desired. 

ALKALOID.  Alkalies  found  existing 
in  vegetables  united  with  peculiar  acids. 
They  are  produced  by  the  plant  during 
growth.  They  dissolve  readily  in  boil- 
ing alcohol,  and  sparingly  in  water: 
they  crystallize  out  of  the  alcohol  by 
cooling  the  latter,  from  which  they  can 
be  separated  in  a  crystalline  form ;  they 
restore  the  blue  color  to  red  litmus,  and. 
render  vellow  turmeric  brown.  The  chief 
alkaloids  are  quinine  and  cinchonine  from 
Peruvian  bark,  nicotine  from  tobacco: 
morphia,  codeine,  narcotine,  thebaine, 
from  the  papaveraceaj ;  and  in  other  fami- 
lies, strychnine,  atropine,  brucine,  vera- 
trine,  emetine,  berberine,  and  cafeine. 
They  all  contain  nitrogen  not  existing  in 
the  form  of  ammonia. 


ALU] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


ALKANET.    A  root  used  for  dyeing  i 
red.  The  plant,  anchusa  Uvxtoria,  belongs  | 
to  the  family  Boraginese,  and  is  a  species 
of  bugloss,  cultivated  largely  in  the  south 
of  France :  the  roots  yield  a  deep  red  to 
alcohol  and  oils,  and  a  dull  red  to  water,  j 
It  is  used  extensively  to  color  ointments,  i 
oils,  cheese,  and  perfumery  in  general.  ! 
White  marble  is  stained  a  deep  tint  by 
the  alcoholic  solution. 

ALLOY.  A  compound  formed  of  two 
or  more  metals  fused  together.  Thus 
bronze  is  an  alloy  of  copper  and  tin ; 
brass  an  alloy  of  copper  and  zinc :  they 
all  have  lustre,  are  sonorous,  elastic,  duc- 
tile, and  malleable,  like  simple  metals. 
Metals  do  not  alloy  indifferently  with 
each  other,  but  are  governed  by  peculiar 
affinities.  Silver  unites  readily  with  lead, 
copper,  and  gold,  but  will  scarcely  alloy 
with  iron.  When  a  metal  is  united  with 
mercury,  it  generally  receives  the  title  of 
an  amalgam.  When  metals  are  united 
in  an  alloy  the  specific  gravity  of  the 
new  compound  is  not  the  mean  of  its 
constituents,  but  occasionally  is  greater 
— in  other  instances,  less  :  its  melting 
point  also  is  not  the  mean  of  the  melting 
points  of  the  two  Inetals,  but  it  is  gene- 
rally somewhat  lower  in  temperature — 
the  fusibility  of  an  allov  is  increased. 
Although  the  number  of  metals  is  very 
great  (43),  yet  only  a  few  are  extensively 
found  or  of  much  use — perhaps  the  num- 
ber frequently  employed  is  not  more 
than  twelve :  where  purity  of  a  metal  is 
not  required,  but  some  property  which 
a  single  metal  does  not  possess,  an  alloy 
is  found  to  supply  the  want.  Even  the 
property  of  an  alloy  itself  may  be  varied 
by  uniting  with  a  portion  of  a  third 
metal.  Thus  in  the  case  of  the  alloy 
brass  ;  when  it  is  required  to  have  brass 
fit  for  turning,  a  small  quantity  of  lead 
is  added.  This  improves  it  for  that  pur- 
pose, but  renders  it  unfit  for  hammering. 
The  number  of  useful  metals  can  be  thus 
multiplied,  as  it  were,  by  the  formation 
of  alloys. 

Alloys  can  only  be  properly  formed  by 
fusion,  as  by  melting  the  two  metals  to- 
gether in  a  crucible.  They  require  to  be 
stirred  well  while  melting,' lest  the  metals 
separate  from  each  other,  the  heavier 
taking  the  bottom  of  the  vessel.  The 
strength  or  cohesion  of  alloys  is  greater 
than  that  of  its  constituents.  The  most 
refractory  metals,  which  can  scarcely  be 
fused  in  a  crucible  at  the  greatest  heat  of 
the  furnace,  melt  down  with  ease  when 
surrounded  by  the  more  fusible  metals. 
The  surfaces  of  the  superior  metal  are 


melted  down  or  washed  away,  layer  by 
layer,  until  the  whole  becomes  liquified. 
Nickel  is  nearly  as  difficult  to  melt  as 
iron;  but  it  is  usefully  employed  with 
copper  in  German  silver,  to  which  it  gives 
whiteness  and  hardness,  and  renders  the 
alloy  less  fusible.  Platinum  cannot  be 
melted  at  the  highest  heat  of  a  furnace, 
but  it  combines  so  readily  with  zinc,  tin, 
and  arsenic  that  it  is  dangerous  to  heat 
one  of  these  substances  m  a  platinum 
spoon,  for  an  alloy  would  be  formed  and 
the  spoon  destroyed. 

An  alloy,  remarkable  for  its  easy  fusi- 
bility, is  made  by  melting  together  eight 
parts  of  bismuth,  five  of  lead,  and  three 
of  tin.  This  melts  in  boiling  water,  even 
in  water  of  the  temperature  198°  Eahr. 
It  is  on  this  account  called  fusible  metal. 
The  proportions  may  be  varied  to  make 
a  more  or  less  fusible  compound.  Safety 
plugs  for  valves  of  steam-boilers,  are 
made  of  this  material :  a  hole  made  in 
the  boiler  is  stopped  with  one  of  these 
plugs,  so  that  when  from  any  derange- 
ment of  the  valve  steam  above  the  usual 
pressure  and  temperature  be  formed,  it 
would  melt  the  plug  and  force  its  way  out 
through  the  aperture  rather  than  burst 
the  boiler.  When  quicksilver  is  added 
to  this  alloy,  it  becomes  more  fusible ; 
and  is  used  by  dentists  for  stuffing  de- 
cayed teeth. 

Solders  are  alloys,  and  generally  con- 
tain a  portion  of  the  metal  they  are  used 
to  connect.     (See  Solder.) 

ALMOND  OIL.  A  bland,  fixed  oil, 
obtained  from  the  seeds  or  kernels  of 
bitter  almonds,  either  by  subjecting  them 
to  pressure  in  a  hydraulic  press  m  the 
cold,  or  by  the  aid  of  hot  iron  plates. 

ALUM.  One  of  the  most  useful  salts 
manufactured  ;  it  is  extensively  employed 
in  dyeing  and  calico-printing,  to  which  it 
supplies  the  mordant.  In  candle-mak- 
ing, it  is  used  to  harden  and  whiten  tal- 
low ;  in  bread-making,  it  is  often  used 
for  a  similar  effect ;  it  is  added  to  paste 
to  prevent  its  decomposition ;  it  is  em- 
ployed in  preparing  and  preserving  skins, 
and  also  m  pharmacy.  Our  alum  was 
unknown  to  the  ancients,  who  under  that 
name  used  a  different  substance,  as  sul- 
phate iron,  or  the  latter  mixed  with  alum 
earth.  Alum  is  composed  of  sulphuric 
acid,  alumina,  or  the  earth  of  clay  and  pot- 
ash. It  is  a  double  sulphate  of  alumina  and 
potash.  Crystals  of  alum  are  sometimes 
found  ready  formed  in  the  earth,  as  along 
the  chain  of  the  Andes — as  aluininitc  in 
Germany,  New-York,  and  other  parts  of 
the  United  States.   The  materials  for  alum 


8 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ALU 


are,  however,  found  in  a  state  of  combi- 
nation almost  fit  for  manufacture  into 
alum  in  various  parts  of  the  world.  In 
Italy,  Hungary,  Sweden,  Scotland,  and 
North  of  England,  there  are  rocks  and 
earths  termed  alum  stone— alum  slate, 
A.  clay,  slate  clay,  and  bituminous  shale. 
These  furnish  the  main  material,  and 
when  treated  in  various  ways  yield  the 
greater  part  of  the  alum  of  commerce. 
These  clays  and  rocks  are  abundant  in 
this  continent.  The  Genesee  black  slate 
of  the  New-York  system  of  rocks  is  highly 
impregnated  with  bitumen  and  withlron 
pyrites  (sulphuret  of  iron) ;  these  by  re- 
acting on  each  other  produce  a  decompo- 
sition of  the  rock,  and  an  approach  to 
the  formation  of  the  salt ;  and  from 
these  is  prepared  in  various  ways  the 
alum  of  commerce.  In  the  slaty  stratum 
there  are,  among  other  elements,  sulphur, 
alumina,  and  iron ;  and  these,  by  the 
long-continued  action  of  air  and  mois- 
ture, lead  to  the  formation  of  sulphate 
of  alumina  and  sulphate  of  iron.  Heat 
aids  this  transformation,  and  hence  there 
are  two  modes  of  treatment — one  for  the 
efflorescent,  or  powdery  ore,  and  one  for 
the  stony  ore. 

Alum  slate,  or  alum  shale,  is  a  very 
abundant  source  of  alum.  It  occurs  in 
Tennessee,  and  in  New-York  in  the  small 
lake  district.  It  occurs  in  the  lower  se- 
condary rocks,  and  in  the  latter  district 
is  exposed  by  the  ravines,  which  have 
cut  their  way  over  and  through  the 
strata  in  the  passage  to  the  Lakes :  the 
Falls  of  Lodi,  in  Seneca  Co.,  N.  Y.,  is 
over  alum  slate,  and  the  rough  mineral 
crystallizes  out  on  the  surface  of  the  cas- 
cade. Alum  shale  is  a  grayish  or  blu- 
ish colored  rock,  splitting  readily,  and 
friable  on  exposure  to  the  air  :  it  dries  or 
effloresces  on  the  surface,  and  acquires 
an  astringent  taste.  The  first  step  m  the 
process  is  the  roasting  of  the  ore.  Some- 
times the  shale  contains  so  much  bitu- 
minous matter  that  after  being  fired  it 
keeps  up  its  own  combustion :  in  most 
cases  it  is  necessary  to  add  additional 
fuel,  either  brushwood  or  coal :  a  thin 
layer  of  wood  is  generally  spread  on  the 
ground,  and  then  above  it  a  layer  of 
slate.  This  is  set  fire  to,  and  while'burn- 
ing  an  additional  layer  of  brushwood  and 
of  slate  are  added,  and  alternate  layers 
are  supplied  as  those  below  become  roast- 
ed: by  this  process  the  iron  pyrites  in 
the  ore  is  decomposed,  the  sulphur  and 
the  iron  are  both  oxydized — the  sulphur 
being  converted  into  sulphuric  acid,  and 
the  iron  into  oxide  of  iron — then  unite  to 


form  sulphate  of  iron,  or  copperas,  and 
any  additional  sulphuric  acid  unites  with 
the  alumina  to  form  sulphate  of  alumina. 
These  salts  are  then  removed  from  the 
ore  by  washing  it.    The  ore  is  put  into 
large  flat  pans   of  wood,   or   masonry, 
called    "steeps,"  and  the   water  is  left 
upon  it  for  twelve  or  sixteen  hours  when 
it  is  fresh  ore :  this  process  is  repeated 
three  times  on  each  batch  of  ore,  dimin- 
ishing the  time  of  maceration  as  the  pro- 
cess is  repeated.    The  water,  which  has 
lain  upon  a  weak  slate,  is  transferred  to 
one  containing  more  saline  matters.  From 
these  steeps  the  liquor  is  pumped  into 
a  series  of  long-arched  boilers,  so  formed 
as  to  apply  heat.     By  this  means  the 
water  is  evaporated,  and  the  highly  con- 
centrated liquor  is  then  transferred  to 
large  coolers,  where  it  remains  for  a  fort- 
night undisturbed.    During  this  interval 
crystallization  goes  on :   the  liquor  con- 
tains  sulphate  of  iron  and  sulphate  of 
alumina,  and  the  former  of  these  separ- 
ates from  the  latter  by  gradually  crystal- 
lizing out.    Sticks  are  immersed  in  the 
liquid  in  the  coolers,  and  around  these 
sticks  large  bundles  of  beautiful  green 
crystals  collect,  forming  the  well-known 
green  vitriol  or  copperas  of  the  shops. 
When  the  crystals  of  copperas  have  been 
removed,  the  remaining  liquor  is  drawn 
off  into  an  evaporating  boiler  in  order 
that  the   sulphate  of  alumina  may  go 
through  the  same  process   as  the   cop- 
peras ;  and  after  being  boiled  down  to  a 
certain  strength,  the  liquor  is  drawn  off 
into  a  cooler.    Sulphate  of  alumina  will 
not  crystallize  without  potash  or  some 
other  alkali  be  added,  and  this  substance 
is  therefore  added  to  the  cooler,  in  which, 
after  some  days  standing,  crystals  of  alum 
are  produced  :  it  is  thus  a  double  salt,  a 
sulpnate  of  alumina  and  a  sulphate   of 
potash.     This  is  crude  alum,  and   it  is 
further  purified  by    other  processes  of 
boiling,  evaporating,  and  crystallizing. 

When  the  hard  or  stony  ore  is  used, 
a  preparatory  process  is  necessary.  This 
ore  is  in  appearance  midway  between 
slate  and  stone  coal,  contains  sulphur, 
iron,  and  alumina,  like  the  decomposed 
ore ;  but  these  three  elements  have  not 
yet  been  combined  into  the  sulphates  of 
iron  and  alumina:  the  aid  of  heat  is  ne- 
cessary for  this  transformation.  The  ore 
after  being  broken  into  small  pieces  is 
built  up  into  long  ridges  with  fuel  be- 
neath, and  air-holes  in  different  parts, 
and  it  is  then  fired  ;  after  which  the  ore 
undergoes  the  same  treatment  as  before 
described.    The  copperas  is  thus  always 


4 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


9 


an  extra  product  in  the  manufacture  of 
alum.  It  is  impure,  and  is  usually  roasted 
at  a  strong  heat ;  and  when  washed 
yields  more  alum.  The  red  residue  after 
roasting  is  ground  to  a  fine  powder,  and 
when  dried  is  used  as  a  Venetian  red  pig- 
ment :  by  altering  the  temperature  at 
which  it  is  dried,  a  yellow  ochre  is  ob- 
tained instead  of  a  red.  In  France  alum 
is  made  from  clay,  which  is  first  finely 
ground,  and  mixed  with  half  its  weight 
of  crude  sulphate  of  potash  :  these  are 
formed  into  balls  five  inches  in  diameter, 
and  calcined  in  the  furnace ;  they  are 
then  transferred  to  the  bottom  of  the 
chamber  in  which  sulphuric  acid  is  made, 
where  they  swell  up,  and  open  on  all 
sides,  owing  to  the  acid  vapor  entering 
them.  They  are  then  lixiviated  with 
water,  and  crystals  of  alum  are  obtained 
by  evaporating  the  liquid. 

Dr.  Turner,  of  England,  took  out  a  pa- 
tent in  1842  for  obtaining  alum  by  the 
decomposition  of  felspar. 

It  is  occasionally  made  from  the  pure 
materials  themselves.  The  finest  pottery 
clay  is  calcined  in  an  oven  to  drive  off  the 
water,  and  the  vegetable  matter  combined 
with  it ;  it  is  then  placed  in  a  tank  sunk 
in  the  ground,  and  to  this  is  added  sul- 
phuric acid  :  the  reaction  is  so  powerful 
that  both  together  soon  form  a  boiling 
mixture,  although  no  heat  bo  applied. 
Water  is  then  added,  and  the  whole  al- 
lowed to  settle ;  the  clear  liquid  (solution 
of  sulphate  of  alumina)  is  then  pumped 
up  into  leaden  vessels,  where  it  receives 
the  addition  of  some  sulphate  of  potash 
as  a  means  of  giving  the  third  ingredient 
necessary  to  form  crystallized  alum.  It 
is,  however,  not  yet  pure,  or  fine  in 
quality,  and  has  to  undergo  the  process 
of  roaming :  this  is  meant  to  imply  the 
production  of  an  alum  similar  to  rock 
alum,  which  derives  its  name  from  Koc- 
cha  in  Syria,  where  it  was  first  made. 
In  roaching,  steam  is  brought  to  act  upon 
the  alum  so  as  to  dissolve  it,  and  form  a 
strong  solution.  This  is  done  in  a  leaden 
vessel,  from  which  the  solution  is  trans- 
ferred to  large  cylindrical  crystallizing  I 
vessels,  where  it  attains  the  final  state  in  | 
which  it  is  sent  into  market. 

There  is  a  peculiarity  about  alum  which 
has  led  to  an  entirely  new  branch  of  i 
manufacture.    Alum  is  not  necessarily  a 
sulphate  of  alumina  and  potash  ;  in  some  ! 
instances  soda,  and  in  others  ammonia,  I 
has  been  used,  instead  of  potash,  forming 
soda  alum  and  ammonia  alum!     These 
bodies  merely  aid  by  facilitating  the  crys- 
tallization of  the  sulphate  of  alumina, 
1* 


but  they  are  of  no  practical  service  in 
the  chief  purpose  to  which  alum  is  ap- 
plied in  the  arts  :  the  sulphate  of  alu- 
mina is  the  real  working  agent,  and  if 
this  could  be  obtained  m  a  pure  and 
solid  state  the  alkali  would  in  most  cases 
be  unnecessary.  It  happens  that  the 
iron  contained  in  small  quantity  in  the 
clay,  and  which  would  injure  the  alum  if 
allowed  to  remain,  is  with  difficulty  re- 
moved except  by  crystallization ;  re- 
cently, however,  a  new  process  for  form- 
ing a  "  patent  alum"  has  been  adopted. 
In  making  this  alum  sulphuric  acid  and 
porcelain  clay  are  used  as  before,  but  the 
clay  is  used  in  greater  proportion,  so  as 
to  form  a  mortar,  which  is  placed  in  a 
heated  trough,  where  it  is  converted  into 
a  dry  earth :  thence  it  is  removed  to 
tanks,  where  water  dissolves  it*  and 
while  here  the  composition  is  actea  upon 
by  an  agent  intended  to  remove  the  iron. 
This  is  yellow  prussiate  of  potash,  which 
by  uniting  with  the  iron  forms  Prussian 
blue ;  this  latter  is  allowed  to  subside, 
the  clear  liquor  decanted  off  and  boiled 
down  to  a  solid  residue,  which  is  formed 
into  cakes  two  inches  thick,  and  it  is 
sent  into  the  market.  It  is  now  an 
opaque  earthy  solid,  differing  from  com- 
mon alum  by  containing  no  potash.  The 
Prussian  blue  is  collected,  and  is  so 
treated  as  to  be  restored  to  the  form 
which  it  had  previous  to  use,  and  is  thus 
ready  for  a  fresh  quantity  of  crude  sul- 
phate of  alumina. 

Crystallized  alum  is  composed  of 

1  atom  of  sulphate  of  alumina, 
1  atom  of  sulphate  of  potash, 
24  atoms  of  water 

Or  by  weight — 

Alumina 10*32 

Potash 9-94 

Sulphuric  acid 33-77 

Water 45-47 

100-00 

The  ammonia  alum  contains  more  water. 
ALUMINA.  An  earth  of  very  com- 
mon occurrence  in  primitive  and  secon- 
dary rocks  :  in  the  minerals  felspar  and 
mica  it  is  associated  with  silica,  iron, 
and  potash ;  from  the  decomposition  of 
these  clay  is  formed.  It  is  the  oxide  of  a 
metal  named  aluminum,  and  it  consists 
of  2  equivalents  of  that  metal  united  to 
3  equivalents  of  oxygen.  It  can  be  ob- 
tained pure  by  adding  ammonia  to  a  so- 
lution of  potash  alum,  washing  the  pre- 
cipitate with  warm  water,  and  drying  it : 


10 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[amb 


it  is  then  hydrated,  or  united  with  water, 
from  which  it  may  be  freed  by  exposure 
to  a  red  heat  in  a  crucible ;  it  is  then  a 
clear  white  powder,  soft  to  the  touch, 
adhesive  to  the  tongue,  and  insoluble  in 
acids.  Its  density  varies  from  2  to  4, 
acquiring  the  latter  gravity  after  being 
burned  ;  when  mixed  with  a  small  quan- 
tity of  water,  it  becomes  doughy  and 
plastic :  if  dried  in  this  state  in  the  air, 
and  then  heated,  it  cracks  and  shrinks 
from  loss  of  water.  This  property  is 
communicated  to  common  clays,  which 
cracks  in  great  droughts,  and  to  model- 
ling clays :  Wedgewood  made  use  of  it 
as  a  measure  of  neat  in  his  pyrometer, 
which  is  now  obsolete.  Alumina  has  a 
great  affinity  for  coloring  principles  and 
organic  compounds,  and  its  use  in  dye- 
ing and  calico-printing  depends  on  its 
affinity  for  these  substances  and  for 
woody  fibre  :  from  its  double  affinity  it 
seizes  upon  the  coloring  matter  and  upon 
the  tissue  of  the  stuff,  and  brings  them 
both  into  contact,  and  holds  them  to- 
gether. It  is  on  this  account  the  basis 
of  mordants.  When  ligneous  fibre  is  not 
present,  and  alumina  be  added  to  a 
coloring  matter  of  vegetable  or  animal 
origin,  it  unites  with  the  latter,  and  car- 
ries it  down  to  the  bottom  of  the  vessel, 
leaving  the  liquor  colorless.  Colors  so 
prepared  are  called  a  lake.  Alumina 
freshly  made  is  soluble  in  acids,  and  acts 
as  a  base  to  them ;  with  potash,  and  a 
few  other  bases,  it  unites,  and  acts  as  an 
acid.  When  moistened  with  nitrate  of 
cobalt,  and  exposed  to  a  red  heat,  it 
affords  a  fine  blue  color,  by  which  it  may 
be  readily  detected  in  small  quantity. 
Alumina  occurs  native  and  pure  in  the 
sapphire,  oriental  ruby,  topaz,  and  chry- 
solite. Gibbsite  and  diaspore  contain 
water  united  with  the  alumina :  corun- 
drum  and  emery  are  less  pure  varieties, 
where  the  alumina  is  mixed  with  a  little 
silica  and  oxide  of  iron. 

AMADOU.  A  fungus  (boletus  igni- 
arius),  which  grows  on  the  cherry,  ash, 
and  other  trees,  prepared  by  the  Ger- 
mans into  tinder  for  striking  lights  with. 
It  is  gathered  in  Autumn,  and  is  cut  and 
beaten  until  it  can  be  readily  torn  by  the 
finger.  In  this  state  it  is  valuable  as  a 
styptic:  by  steeping  with  nitre  it  forms 
the  tinder.  Puff-balls  are  frequently 
used  as  a  substitute  for  amadou. 

AMALGAM.  The  union  of  mercury 
or  quicksilver  with  other  metals.  Many 
of  fhet-e  crystallize  definitely,  and  may 
be  separated  from  the  excess  of  mercury 
with  which  they  are  surrounded.    They 


are  mostly  brittle  and  soft.  Tin  and 
mercury  unite  by  mere  rubbing ;  it  has  a 
high  reflecting  surface,  and  is  used  as 
the  back  of  looking-glasses.  Amalgam 
for  the  electrical  machine  is  made  of 
mercury  4  parts,  zinc  2  parts,  and  1  part 
tin.  These  when  melted  and  rubbed  up 
with  a  little  lard  are  fit  for  use. 

AMALGAMATION.  The  mode  by 
which  silver  ores  may  be  reduced,  mer- 
cury being  used  in  the  process.  The 
separation  of  gold  from  sand  and  im- 
purities by  mercury  is  an  amalgamation. 

AMBEK.  A  fossil,  vegetable,  solid, 
resin,  of  various  tints  of  yellow :  it  is 
hard  and  transparent,  when  polished,  a 
little  heavier  than  water,  has  a  resinous 
taste,  and  an  odor  resembling  turpen- 
tine :  it  burns  readily,  giving  off  a  white, 
pungent,  aromatic  smelling  vapor.  By 
friction  it  becomes  highly  charged  with 
negative  electricity,  and  from  this  pro- 
perty being  first  observed  in  this  mineral, 
called  by  the  ancients  electron,  it  received 
the  name  electricity.  According  to  Gop- 
pert  and  others,  amber  is  the  indurated 
resin  of  various  fossil  trees  of  the  family 
coniferse.  It  is  found  in  the  same  con- 
dition in  all  latitudes,  lying  in  nodules 
or  masses,  disseminated  in  the  sand  or 
fragments  of  lignite  (brown  coal)  of  the 
plastic  clay  at  the  junction  of  the  lower 
tertiary  with  the  upper  secondary  bed 
(chalk) :  the  size  varies  from  that  of  a 
nut  to  masses  weighing  several  poimds. 
It  is  sometimes  found  containing  insects 
— a  proof  of  its  once  being  in  a  soft  or 
semi-fluid  condition.  Pictet  has  num- 
bered 800  fossil  species  of  insects-  occur- 
ring in  it.  The  feather  of  a  bird  and  a 
little  of  the  hair  of  the  bat  have  been  found 
imbedded,  with  one  or  two  molluscous 
shells.  These  species  are  those  which 
could  only  have  inhabited  tropical  cli- 
mates. Copal  resembles  amber,  and 
common  copal  inclosing  insects  has  been 
often  fraudulently  sold  for  amber.  It 
occurs  in  Pomerania,  and  on  the  other 
shores  of  the  Baltic,  thrown  up  on  the 
sand  after  storms.  It  is  also  found  in 
the  beds  of  streams.  Pits  are  occasion- 
ally sunk  above  100  feet  down  in  the 
sand,  and  the  amber  sought  for  by  a 
true  mining  operation.  It  is  found  in 
Sicily  associated  with  bitumen  in  beds  of 
clay  and  marl ;  also  in  Poland,  Saxony, 
Siberia,  and  Greenland.  The  finer  kinds 
are  used  for  ornament,  as  ear-rings, 
bracelets,  necklaces,  &c. ;  and  the  coarse 
kind  in  medicine  and  the  arts.  Amber 
dissolved  in  drying  linseed-oil  makes  a 
good  durable  varnish.    With  resin,  as- 


ANC] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


11 


phaltum.  and  drying  oil,  it  forms  the 
coachmaker's  varnish.  Amber  furnishes 
an  oil  used  in  perfumery  and  also  suc- 
cinic acid  used  in  chemistry.  (See  Var- 
nish.) 

AMBERGRIS.  A  substance  used  in 
perfumery.  It  is  found  swimming  on  the 
sea,  off  the  coast  of  Coromandel,  Japan, 
Moluccas,  and  Madagascar.  It  is  the  pro- 
duct of  a  diseased  condition  of  the  liver 
of  the  spermaceti  whale  ;  its  color  is  gray, 
white  or  marbled  yellow,  and  black. 

AMIANTHUS.  A  hornblend  mineral. 
(See  Asbestus.) 

AMMONIA.  Volatile  alkali,  first  ob- 
tained by  Priestly  in  a  gaseous  form,  from 
sal-ammoniac,  whence  its  name.  It  is  a 
volatile  gas,  composed  of  one  equivalent 
of  nitrogen  and  three  equivalents  of  hy- 
drogen. It  is  found  in  tlie  vegetable  and 
animal  kingdom.  Urine  decomposing 
always  contains  it:  hence  the  use  of  that 
substance  in  making  alum,  scouring  wool, 
<fcc.  Ammonia  is  found  united  with  na- 
tive oxide  of  iron,  in  charcoal,  and  all 
soils  which  are  turned  up  and  exposed  to 
the  air.  Rain  water  contains  traces  of 
ammonia  derived  from  the  air,  in  which 
it  is  present  in  minute  quantities. 

Ammonia  cannot  be  made  by  the  direct 
union  of  its  elements :  one  of  these  sub- 
stances must  be  in  the  nascent  state. 
The  usual  mode  of  manufacturing  is  to 
mix  sal-ammoniac,  or  hydro-chlorate  of 
ammonia  reduced  to  powder,  with  an 
equal  weight  of  fresh  slaked  slime  j  these 
are  to  be  put  into  a  retort,  with  just  so 
much  water  as  makes  the  mass  become 
lumpy ;  on  applying  a  gentle  heat  to  the 
retort,  the  ammonia  comes  off  in  large 
quantities  as  a  gas,  and  if  desired  pure, 
may  be  collected  in  vessels  over  the  pneu- 
matic trough.  By  this  process  the  lime  re- 
moves the  hydro-chloric  acid,  forms  with 
it  chloride  of  calcium  and  water,  and  the 
ammonia  is  set  free  ;  if  received  into  ves- 
sels of  water,  it  dissolves  very  speedily, 
water  at  50°  taking  up  670  times  its  vo- 
lume of  gas,  and  the  density  of  the  solu- 
tion diminishes  as  the  strength  increases. 
A  saturated  solution  of  ammonia  contains 
32J  per  cent,  of  gas,  and  has  a  sp.  gr.  of 
•8750.  This  is  called  liquid  ammonia,  and 
is  the  liquor  ammoniae  of  the  pharmaco- 
peia; it  is  colorless,  transparent,  very 
pungent,  and  has  well  marked  alkaline 
propei-tie^.  It  weakens  by  exposure  to 
air  or  heat,  the  ammonia  flying  off  rapidly. 
It  blues  red  litmus,  and  changes  vegeta- 
ble blues  to  green:  it  turns  turmeric  and 
vegetable  yellows  brown,  and  unites  with 
acids  to  form  a  numerous  class  of  3alts. 


Organic  bodies  which  contain  nitrogen, 
in  fermenting  yield  ammonia,  and  gene- 
rally at  the  same  time  carbonic  acid. 
When  hoofs,  bones,  tendons,  horns,  &c, 
are  heated  in  iron  cylinders,  they  are  de- 
composed, and  carbonate  of  ammonia  is 
set  tree  along  with  an  empyreumatic  oil : 
when  freed  from  the  latter  it  is  termed 
spirit  of  hartshorn.  The  gluten  of  corn, 
wheat,  and  other  cerealia,  yield  ammonia 
when  heated  ;  it  is  also  found  in  soot,  and 
in  great  abundance  when  bituminous  coal 
is  heated  to  redness,  as  in  the  manufac- 
ture of  gas. 

ANCHOR.  A  heavy  iron  hook  of  great 
strength,  used  to  hold  on  a  ship  to  the 
ground,  and  fasten  itself  in  a  certain  situ- 
ation  by  means  of  a  rope.  Too  much 
importance  cannot  be  attached  to  the  me- 
chanism and  construction  of  anchors,  for 
upon  these  depends  the  safety  of  the 
ship,  especially  on  lee  shores,  where 
otherwise  the  vessel  may  be  stranded  oi 
wrecked.  The  earliest  anchors  were 
doubtless  heavy  stones,  around  which  a 
rope  passed,  and  which,  by  its  weight, 
retained  the  vessel  in  its  place.  The 
Chinese  use  crooked  pieces  of  heavy  wood 
at  the  present  day.  The  action  of  the 
modern  anchor  is  to  bite  the  ground,  and 
from  the  direction  of  the  strain  upon  it, 
the  anchor  cannot  move  without  plough- 
ing up  the  ground  in  which  the  fluke  or 
hook  is  sunk.  When  this  unhappily  oc- 
curs, it  arises  from  the  softness  oi'  the 
ground,  or  the  violence  of  currents  and 
waves.  The  ship  is  then  said  to  drag 
her  anchor.  When  well  anchored,  the 
cable  will  break,  or  the  fluke  will  be  snap- 
ped off  and  left  in  the  soil,  rather  than 
loope  its  hold.  Anchors  have  different 
names,  according  to  their  sizes  and  the 
purposes  they  serve,  as  sheet,  best  bower, 
small  bower,  spare,  stream,  and  kedge 
anchor.  The  largest  ships  have  seven 
anchors,  the  smaller,  as  brigs,  cutters,  and 
schooners,  only  three  or  four.  The  ma- 
nufacture of  anchors  requires  great  know 
ledge  of  the  structure  of  iron,  and  skill 
in  manufacturing  it. 

The  shank  of  an  anchor  is  made  long, 
so  that  the  stock,  or  cross-piece,  near  the 
cable-ring,  may  have  greater  power  in  di- 
recting one  or  other  of  the  arms  down- 
wards :  where  it  joins  the  stock  it  is 
square  to  receive  and  hold  the  former 
sccureiy.  In  the  square  part  is  a  hole  for 
receiving  the  ring  for  the  cable.  The 
arms  form  an  angle  of  56°  with  the  shaft, 
they  are  rounded  for  the  first  half  of  their 
length,  and  the  remainder  is  flattened 
out  and  is  called  the  blade.    The  length 


12 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[anc 


of  the  arm  is  nearly  half  the  length  of  | 
the  shaft.  The  stock  is  generally  formed 
of  two  oak  beams  embracing  the  square, 
and  firmly  united  by  nuts,  iron  bolts,  and 
hoops  ;  occasionally  it  is  made  of  wrought 
iron,  and  then  it  passes  through  a  hole 
in  the  square. 

The  weight  of  anchors  for  vessels  is 
generally  apportioned  to  the  tonnage,  the 
weight  of  the  anchor  in  hundred  weights 
being  one-twentieth  the  number  of  tons 
of  Imrden, — thus  a  ship  of  1000  tons 
would  require  a  sheet-anchor  of  50  cwt. 
In  the  English  navy  1  cwt.  is  allowed  for 
every  gun  ;  an  80  gun  ship  will  have  an 
anchor  of  SO  cwt.  The  weight  of  an  an- 
chor ten  feet  long,  is  11*4  cwt,  and  if  all 
forms  of  anchor  be  the  same,  the  weights 
would  be  as  the  cubes  of  the  lengths : 
hence  the  weight  of  an  anchor  can  be 
found  by  multiplying  the  cube  of  its 
length  by  *0114.  This  gives  a  sufficiently 
close  approximation;  but  for  large  an- 
chors this  is  too  small,  because  the  thick- 
ness is  greater  in  proportion. 

Anchors  have  been  made  with  only  one 
arm.  Mr.  Stuard  patented  one  ot  this 
kind  some  years  ago.  To  insure  the  an- 
chor falling  the  right  way,  with  the  fluke 
down,  the  shank  was  shortened,  so  that 
when  suspended  by  the  cable,  it  will  cant 
the  most,  and  when  it  has  hold  in  the 
ground,  the  ship  will  ride  more  safely,  as 
a  long  shank  is  more  likely  to  be  bent,  or 
broken  from  its  hold.  The  bars  which 
compose  the  anchor  are  put  together  in 
one  length,  there  is  no  welding  together, 
and  its  strength  is  thus  much  increased. 
The  great  object  in  anchors  is  to  provide 
the  greatest  strength,  by  preserving  such 
a  disposition  of  the  fibres  of  the  metal  as 
shall  conduce  to  this.  The  crossing  or 
bending  of  fibres  at  the  junction  of  the 
flxikcB  with  the  shank  and  with  the  crown 
should  be  avoided,  as  great  strength 
is  required  in  these  parts.  In  this  re- 
spect most  anchors  are  defective,  for  in 
connecting  the  shanks  with  the  crown- 
pieces,  the  grain  of  the  metal  is  crossed 
or  curved,  so  as  to  strain  the  fibre  and 
induce  a  Avcakncss.  Mr.  Piper,  in  1S22, 
proposed  new  forms  and  constructions  to 
meet  and  overcome  this  objection.  Mr. 
Kodgers,  Lieut.  K.N.,  England,  in  1846 
patented  an  improved  construction  of 
stocks,  shanks,  arms  and  palms  of  an- 
chors, in  such  a  mnnner,  that  they  will, 
with  the  same  weight  of  metal,  be 
stronger  in'thc  direction  in  which  the 
strain  comes  on  them,  and  have  greater 
holding  power  than  any  which  have  hi- 
therto been  used.    The  form  is  based  on 


the  principle  of  the  wedge,  which  is  a 
cross-section  of  the  stem  or  shank,  and 
being  of  a  rectangular  form,  is  better  cal- 
culated to  resist  the  strain  to  which  that 
particular  part  is  subjected,  than  any  an- 
chor of  the  usual  form.  The  stem  is  re- 
duced at  the  end  next  the  stock,  where 
the  principal  strain  being  tersion  or  twist- 
ing, it  is  better  suited  to  resist  than  any 
other.  The  arm  is  wedge-shaped,  the 
outer  circumference  of  the  arc  being 
broader  than  the  inner,  thus  disposing  of 
the  metal  so  as  to  obtain  the  greatest 
amount  of  strength,  and  at  the  same  time 
have  a  greater  holding  power  by  the  pres- 
sure of  the  soil  on  the  sides  of  the  arms. 
The  palms  are  made  with  the  bevelled 
sides  in  front  instead  of  the  back,  as  hi- 
therto :  this  also  produces  a  greater  hold- 
ing power,  for  in  dragging  the  anchor  he 
found,  from  actual  experiment,  that  the 
soil  fills  up  behind  the  palm,  and  prevents 
the  water  entering  the  rut.  In  applying 
one  part  of  this  invention  to  anchors  al- 
ready made,  a  piece  of  iron  is  welded  on 
to  the  front  of  the  arm  to  form  the  palm, 
the  parts  projecting  beyond  the  arm  being 
bent  back,  and  forming  the  bevelled  sur- 
faces, which  will  have  a  similar  effect  to 
that  already  described  when  the  palms 
are  forged  out  in  the  solid. 

Anchors  arc  sometimes  liable  to  be  dis- 
ttirbed  by  ground  ice  being  formed  at  the 
bottom  of  the  water ;  this  occurs  when 
the  temperature  is  lower  and  the  water 
not  deep.  Anchors  to  which  buoys  have 
been  attached,  have  been  raised  in  the 
Baltic  sea  owing  to  this  cause,  and  stones, 
from  3  to  6  lbs.,  have  been  floated  to  the 
surface  by  the  lifting  power  of  the  ice. 
Under  such  circumstances,  the  slow  for- 
mation of  ice  round  an  anchor  tends  to 
give  it  a  lifting  power  and  make  it  rela- 
tively lighter,  so  that  upon  a  slight  mov- 
ing force  applied  to  it,  or  even  upon  a 
further  formation  of  ice,  the  anchor  gra- 
dually rises  out  of  the  soil. 

ANCHOVY.  Small  soft-finned  fishes  of 
the  herring  species,  inhabiting  the  tropi- 
cal seas  of  this  continent  and  India. 
They  arc  caught  in  the  Mediterranean  sea 
in  abundance  from  May  to  July,  the  fish 
then  leaving  the  Atlantic  to  deposit  their 
spawn  on  these  shores.  The  fishing  is 
carried  on  by  night,  the  anchovies  being 
attracted  by  the  charcoal  fires  which  are 
burned  in  the  stem  of  the  boats.  The 
head,  gills,  and  entrails  arc  removed,  and 
the  bodies  salted  and  packed  in  small 
casks,  from  5  to  25  lbs.  weight,  and  if  the 
air  have  been  excluded,  they  will  keep 
good  for  any  length  of  time. 


ANEj 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


13 


ANEMOMETER.  A  measurer  of  the  ve- 
locity or  force  of  wind.  To  ascertain  this 
force  is  sometimes  of  considerable  mo- 
ment to  mechanical  science.  Cronne,  in 
the  17th  century,  andWolfius  and  others 
in  later  times,  have  invented  instruments 
for  this  purpose  with  but  partial  success ; 
in  them  the  velocity  of  the  wind  was 
measured  by  its  mechanical  force,  as  by 
the  compression  of  a  spiral  spring,  or  by 
the  elevation  of  a  weight  round  a  centre, 
acting  at  the  arm  of  a  variable  lever. 
Leslie's  anemometer  depended  on  the 
principle  that  a  stream  or  air  had  a  cool- 
ing power  in  proportion  to  its  velocity. 
Linct's  anemometer  raises  a  column  of 
fluid  above  the  general  level  of  its  sur- 
face. It  consists  of  two  tubes,  9  inches 
long  and  £  inch  wide,  connected  together 
at  the  bottom  by  a  tube  of  very  narrow 
bore ;  a  thin  metal  cap,  bent  at  right  an- 
gles, is  fitted  upon  one  extremity,  so  that 
it  mav  receive  the  current  of  air  in  a  hori- 
zontal direction.  The  tubes  are  half  filled 
with  water,  and  a  scale  on  which  inches 
and  tenths  can  be  read  off,  is  placed  be- 
tween the  tubes.  When  the  wind  blows 
into  the  cap  it  depresses  the  water  in  the 
first  tube  and  raises  it  in  the  second,  so 
that  the  distance  of  the  surfaces  of  the 
fluid  is  the  length  of  a  column  of  water 
equal  to  the  base  of  the  column  of  fluid. 
The  absolute  velocity  of  the  wind  is  cal- 
culated from  the  height  of  the  column  of 
water,  or  it  may  be  ascertained  from 
tables  made  for  the  purpose. 

Dr.  Whewel's  form  of  anemometer  is 
one  in  much  use.  By  means  of  a  vane 
a  windmill-fly  is  presented  to  the  wind, 
the  fly  revolving  with  more  or  less  velo- 
city, according  to  the  rapidity  of  the 
wind.  By  means  of  an  endless  screw  and 
wheel-work  attached,  the  motion  of  the 
fly  brings  a  pencil  down  over  a  fixed  cy- 
linder, tracing  a  certain  path,  which  may 
be  longer  or  shorter,  as  the  wind  is  rapid 
or  slow.  The  pencil  descends  only  one- 
twentieth  of  an  inch  with  10,000  revolu- 
tions of  the  fly.  The  surface  of  the  cylin- 
der is  whited,  and  divided  into  thirty-two 
equal  parts  by  vertical  lines,  the  spaces 
corresponding  to  the  points  of  the  com- 
pass, so  that  a  mark  left  by  the  pencil  in 
these  spaces  indicates  the  direction  of  the 
wind.  The  pencil  moves  in  two  ways: 
downwards  to  indicate  the  velocity,  and 
laterally  to  indicate  its  direction.  The 
cylinder  is  fixed,  the  vane  and  wheel- 
work  being  on  a  turning-table  to  which 
the  pencil  is  connected,  and  these  are 
obedient  to  the  wind.  The  friction  in 
this  machine  is  very  great,  arising  from 


the  wheel-work  and  the  pencil ;  in  the 
former  it  chiefly  resides,  because  a  rapid 
motion  has  to  be  converted  into  a  descend- 
ing slow  one. 

Osier's  anemometer  traces  the  direction 
of  the  wind  and  its  pressure  upon  a 
ffiven  space,  with  the  fall  of  rain,  on  a  re- 
gister divided  into  twenty-four  spaces, 
corresponding  to  the  hours  of  the  day. 
A  clean  paper  register  is  placed  on  the 
board  every  day,  which  is  carried  on  by 
clock-work  behind  three  pencils  or  in- 
dices. Tiie  board  moves  on  friction  rol- 
lers, and  is  kept  constantly  and  hourly 
moving,  so  that  a  continued  record  or 
trace  of  the  direction  and  pressure  of  the 
wind,  together  with  the  amount  of  rain, 
is  left  on  the  paper,  and  it  indicates  the 
direction,  the  duration,  and  the  force  of 
the  wind. 

Mr.  Philipps,  in  a  paper  read  to  the 
British  Association,  has  reproduced  Les- 
lie's principle  in  his  "  Anemoscope,"  in 
which  he  proposes  to  measure  the  velo- 
city of  air  by  the  rapidity  of  evaporation, 
and  the  cold  produced  thereby.  When 
the  bulb  of  a  thermometer,  covered  with 
cotton  wool,  is  immersed  in  water  and 
exposed  to  the  air,  the  evaporation  is 
known  to  produce  a  given  amount  of 
diminution  of  temperature,  and  when 
the  thermometer  is  moved  through  the 
air,  the  rapidity  of  evaporation  is  in- 
creased. By  repeated  trials  in  tranquil 
air,  and  when  the  thermometer  was  in 
motion,  he  was  enabled  to  ascertain  the 
increased  rates  of  cooling  by  various  de- 
grees of  speed,  and  on  the  other  hand  to 
tell  the  amount  of  speed  by  the  rapidity 
of  cooling.  He  tested  the  instrument  on 
the  South-Western  Railway  (England), 
and  when  the  carriages  were  at  the  velo- 
city of  thirty-six  miles  an  hour,  his 
new  anemometer  indicated  correctly  the 
amount  of  velocity  in  its  being  held  two 
feet  from  the  carriage. 

Dr.  Kobinson,  oi  Armagh,  Ireland,  in 
1846  constructed  and  worked  an  anemo- 
meter, the  connection  of  the  motion  of 
which  with  the  velocity  is  subject  to  lit- 
tle variation,  and  is  of  easy  determination. 
It  consists  of  two  or  three  arms  attached 
to  a  spindle,  carrying  at  their  extremities 
hollow  hemispheres  of  tin  and  copper, 
with  the  hollows  of  the  hemispheres  all 
turned  in  the  one  direction.  The  force 
of  the  wind  exerted  on  the  concave  sur- 
face being  four  times  greater  than  on  the 
convex,  the  spindle  is  made  to  turn  in 
the  same  direction,  whatever  way  the  wind 
blows.  Attached  to  the  spindie  are  the 
count-wheels  of  a  gasometer,  and  the  ve- 


14 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[ANN 


locity  thus  determined  is  exactly  the  one- 
third  of  that  of  the  wind.  So  trivial  is 
the  friction  in  this  machine  compared 
with  its  power,  that  its  motion  was  quite 
perceptible  in  breezes  which  were  too 
gentle  to  disturb  the  leaves  on  neighbor- 
ing poplar  trees.  It  is  the  most  correct 
anemometer  as  vet  invented. 

ANEROID.  A  new  patent  French  ba- 
rometer. The  principle  of  its  construc- 
tion is  this  :  a  cylinder  of  copper,  with  a 
very  thin  and  corrugated  end,  was  par 
tialiy  exhausted  and  hermetically  sealed, 
the  effect  of  the  varying  pressure  of  the 
atmosphere  on  the  thin  end  was  magni- 
fied by  a  system  of  levers,  so  as  to  affect 
the  index  of  a  dial  very  little  larger  than 
that  of  a  watch.  The  indications  of  this 
instrument  have  been  tested,  by  placing 
it  under  the  receiver  of  an  air-pump,  and 
observing  its  march  in  comparison  with 
the  indications  of  the  long  gauge,  and 
they  were  found  to  agree  to  less  than 
one-hundredth  of  an  inch.  The  con- 
struction of  this  barometer  consists  in 
"  the  application  of  thin  sheets  of  metal, 
glass,  India-rubber,  or  other  flexible  ma- 
terial, to  certain  apparatus  employed  for 
measuring  the  pressure  and  elasticity  of 
the  air  and  other  fluids  in  such  a  man- 
ner as  to  form  a  buffer,  or  cushion,  suscep- 
tible of  the  slightest  variation  of  pressure 
of  the  atmosphere  or  fluid  with  which  it 
is  in  contact,  and  indicating  the  amount 
of  pressure  by  the  amount  of  depression." 
A  detailed  description  of  this  barometer 
is  given  in  the  London  Mechanics'  Maga- 
zine, No.  1307. 

ANIME.  An  exudation  of  the  cour- 
baril  tree  of  Cayenne  and  the  Equatorial 
districts  of  South  America.  It  is  exported 
in  lumps  of  different  sizes,  often  includ- 
ing perfect  insects,  and  parts  of  other  or- 
ganic remains  of  living  species :  hence  it 
has  derived  its  name  as  being  animated. 
It  contains  a  little  volatile  oil,  is  resinous, 
of  a  light  brown  color,  brittle,  and  trans- 
parent. Alcohol  and  essential  oil  of 
caoutchouc  mixed,  dissolve  amine"  into  a 
jelly,  but  not  perfectly. 

ANNEALING,  or  Neaung.  A  pro- 
cess applied  in  the  manufacture  of  glass 
and  some  metals,  to  prevent  the  particles 
arranging  themselves  in  that  condition 
which  produces  a  brittle  quality.  When 
a  glass  vessel  is  allowed  to  cool  immedi- 
ately after  being  blown,  it  will  often  bear 
to  be  struck  violently  on  the  outside  with 
a  stone  or  hammer  without  injury;  but 
if  a  small  piece  of  glass  be  gently  dropped 
into  it,  flies  to  pieces  either  immediately 
or  after  a  few  minutes — a  slight  scratch 


is  often  sufficient  to  break  it.  This  curi- 
ous phenomenon  of  unannealed  glass  is 
illustrated  in  the  Bologna  phial,  and 
Prince  Rupert's  drops.  The  former  will 
bear  a  pistol  bullet  to  fall  on  it  from  a 
height  of  two  feet  without  harm  ;  but  if 
a  grain  of  sand  drop  into  it,  it  flies  to 

Eieces.  These  phials  lose  this  property 
y  age.  Rupert's  drops  are  glass  melted 
off  a  rod,  and  allowed  to  drop  into  cold 
water :  many  will  burst  in  the  water,  but 
those  which  escape  show  the  unanneal- 
ed property  remarkably.  They  may  be 
struck  with  a  hammer  on  the  bulb-end 
unharmed ;  but  snapping  off  an  extrem- 
ity of  the  capillary  tail,  makes  the  whole 
drop  fly  to  pieces  so  small  as  to  be  fine 
dust.  If  the  drops  and  the  phials  be 
heated  and  allowed  to  cool  slowly,  they 
lose  this  property.  By  sudden  cooling, 
the  particles  of  glass  have  not  time  to 
arrange  themselves  in  that  form  which 
constitutes  stable  equilibrium,  and  hence 
on  the  slightest  disturbance  at  favorable 
points,  an  attempt  is  made  at  re-arrange- 
ment. Glass  forms  one  of  the  few  ex- 
ceptions to  the  law  that  bodies  contract 
in  size  in  passing  from  the  fluid  to  the 
solid  form.  When  it  is  allowed  to  cooi 
slowly  its  molecules  arrange  themselves 
in  a  fibrous  form  so  that  freedom  of  mo- 
tion or  elasticity  of  the  whole  mass  re- 
sults ;  and  the  substance  can  propagate 
vibrations  from  one  extremity  to  the 
other.  But  when  melted  glass  is  sud- 
denly cooled,  the  solidification  of  the  sur- 
face occurs  so  fast  that  the  particles  of 
the  interior  are  enclosed  before  they 
have  had  time  to  arrange  themselves  hi 
this  elastic  condition.  The  cohesion  of 
the  particles  is  but  slight,  a  partial  force 
overturns  it.  Drinking  glasses  which 
are  unannealed  and  happen  to  be  thick, 
are  easily  broken  on  that  account  when 
they  are 'thrown  into  vibrations.  While 
annealing,  the  glass  is  kept  at  a  condition 
nearly  fluid  for  several  hours,  by  which 
means  the  interior  particles  can  expand 
and  crystallize  regularly.    Mr.  Pcllat  has 

S roved  that  this  arrangement  of  particles 
oes  take  place  :  he  found  that  two  tubes 
of  equal  size  (forty  inches  long),  the  one 
which  was  annealed  contracted  one-six- 
teenth of  an  inch  more  than  that  which 
was  cooled  in  the  air.  Glasses  which  are 
exposed  to  rapid  transitions  of  tempera- 
ture, may  be  annealed  better  than  is  done 
in  the  glass-house,  by  placing  them  in  a 
vessel  of  cold  water  and  raising  it  to  the 
boiling  point,  and  keeping  it  so  for  some 
hours.  Lamp-shades  ought  to  be  heated 
always  in  this  way. 


ant] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


15 


When  metals  have  been  hammered 
out  very  much  they  become  brittle,  and 
they  will  crack  if  it  be  carried  much  far- 
ther :  their  malleability  is  restored  by 
the  workman  annealing  them,  or  heating 
them  red  hot.  The  annealing  seems  to 
remove  the  closeness  of  the  proximity  of 
the  particles  of  metal  which  the  hammer- 
hardening  had  produced.  In  the  manu- 
facture of  some  articles  of  steel  after  they 
have  been  hammered  into  shape,  they 
arc  annealed  to  allow  of  their  being  cut 
by  the  scissors  or  file.  In  wire  drawing, 
in  the  rolling  and  flattening  of  vessels, 
it  is  necessary  to  anneal  occasionally, 
otherwise  the  metal  would  become  too 
hard  and  woidd  not  extend.  Iron  and 
steel  are  occasionally  annealed  in  the 
open  fire,  and  left  to  cool  gradually  by 
simple  removal.  This  oxydizes  the  sur- 
faces and  destroys  the  steeling. 

Soft  metals,  such  as  tin  and  lead,  are 
annealed  bv  being  dipped  into  hot  water. 

ANNOTTO.  The  red  coloring  matter 
of  the  Bixa  Orellana,  a  plant  of  the  "West 
India  islands,  where  it  is  cultivated  on 
the  banks  of  rivers.  As  obtained  in 
commerce,  it  is  a  dry  and  hard  paste, 
made  from  the  seeds  into  a  pulp,  which, 
after  having  fermented,  is  rolled  into 
pieces  of  two  or  three  pounds'  weight : 
it  is  imported  under  the  names  annotto, 
Eoucou,  or  Orleans,  and  is  used  occa- 
sionally as  an  orange  dye  and  for  color- 
ing cheese.  It  imparts  little  color  to  wa- 
ter, but  dissolves  in  alcohol  and  alkaline 
solutions :  its  color  is  not  materially  al- 
tered by  acids  or  alkalies. 

ANTHRACITE.  (Gr.  av6p4,  charcoal.) 
Mineral  carbon.  A  difficultly  combustible 
species  of  coal. 

ANTIAR.  (A.  Upas.)  A  Javanese 
poison. 

ANTI- ATTRITION.  A  compound  ap- 
plied to  machinery  to  prevent  the  effects 
of  friction.  It  frequently  consists  of  a 
mixture  of  plumbago  with  some  greasy 
material. 

ANTICLINAL  AXIS.    (Gr.  dvri 
against,   and  k\ivciv,   to  incline.)     If  a 
range  of  hills  or  a  valley  be  composed  of 
strata  which,  on  the  two  sides,  dip  in 


opposite  directions,  the  imaginary  line 
that  lies  between  them,  towards  which 
the  strata  on  each  side  rise,  is  called  the 


anticlinal  axis.  In  a  row  of  houses  with 
steep  roofs  facing  the  south,  the  slates 
represent  inclined  strata  dipping  north 
and  south,  and  the  ridge  is  an  east  and 
west  anticlinal  axis  (Lyell).  In  the  an- 
nexed diagram,  a  a  are  the  anticlinal,  b  b 
the  synclinal  lines. 

ANTIMONIC  ACID.  The  peroxide  of 
antimonv.     (See  Antimony.) 

ANTIMONY.  A  brittle  metal  of  a 
silver  white  color;  specific  gravity,  (5.7, 
Fuses  at  810°,  or  just  at  a  red  heat.  The 
principal  properties  of  this  metal  were 
hrst  described  in  the  "  Currus  Trium- 
phalis  Antimonii"  of  Basil  Valentine, 
published  towards  the  end  of  the  13th 
century.  When  heated  in  an  open  vessel, 
it  gradually  combines  with  oxygen,  and 
evaporates  in  a  white  vapor.  There  are 
three  oxides  of  antimony.  The  protoxide 
consists  of  65  antimony  +12  oxygen  ;  it 
is  a  grayish  ;vhite  powder  eminently 
purgative,  suuorific,  and  emetic ;  and  as 
such,  of  much  importance  in  medicine. 
It  is  the  active  base  of  emetic  tartar  and 
of  James's  powder.  The  other  oxides  of 
antimony,  from  combining  with  certain 
bases,  have  been  called  antimonious  and 
antimonic  acid  ;  they  consist  respective- 
ly of  65  antimony  +  16  oxygen,  and 
65  +  20.  The  combination  of  chlorine 
and  antimony  was  known  to  the  old 
chemists  under  the  name  of  butter  of  an- 
timony. The  principal  ore  of  antimony 
is  the  sulphvret :  it  is  met  with  in  com- 
merce, melted  into  conical  ingots,  under 
the  name  of  crude  antimony.  It  is  of  a 
bluish  gray  color,  metallic  iustre,  and  a 
striated  texture ;  specific  gravity  4-62  ;  it 
is  much  more  easily  fusible  than  the  pure 
metal.  Antimony  forms  brittle  alloys 
with  some  of  the  most  malleable  metals  : 
when  gold  is  alloyed  with  a  two-hun- 
dredth part  of  antimony,  the  compound 
is  brittle ;  and  even  the  fumes  of  anti- 
mony in  the  vicinity  of  melted  gold  are 
sufficient  to  render  it  brittle.  Alloyed 
with  lead  in  the  proportion  of  1  to  16,  and 
a  small  addition  oi  copper,  it  forms  the 
metal  used  for  printer's  types  :  with  lead 
only,  a  white  and  rather  brittle  com- 
pound is  formed,  used  for  the  plates  upon 
which  music  is  engraved.  With  iron  it 
forms  a  hard  whitish  alloy,  formerly 
called  martial  regtilus:  12  parts  of  tin  and 
1  of  antimony  form  hard  pewter.  The 
white  metal  spoons  and  teapots  are  form- 
ed of  an  alloy  of  100  tin,  8  antimony,  2 
bismuth,  and  2  copper. 

Antimony  is  the  stimmi,  or  stibium,  of 
the  old  chemists.  The  protoxide  of  anti- 
mony has  been  used  in  France  and  Eng- 


16 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


[a<ju 


land  lately  as  a  white  paint  in  substitu- 
tion for  carbonate  of  lead. 

APATITE.  Native  phosphate  of  lime. 
(See  Phosphorite.) 

APIIRITE.  A  soft  friable  carbonate 
of  lime. 

AQUA.  Water.  A  word  of  uncer- 
tain derivation. 

AQUA  MARINE.    Beryl. 

AQUA  FORTIS.    Nitric  acid. 

AQUA  EEGIA.  A  mixture  of  ni- 
tric and  muriatic  acids,  so  called  from  its 
power  of  dissolving  the  noble  metals,  gold 
and  platinum. 

AQUATINT.  (Lat.  aqua,  water,  tinta, 
dyed.)  In  engraving,  a  species  of  exe- 
cution resembling  an  Indian  ink  drawing 
in  effect.     (See  Engraving.) 

AQUEDUCT.  (Lat.  aqua,  water,  and 
ductus,  a  conduit.)  A  conduit  or  chan- 
nel for  conveying  water  from  one  place 
to  another ;  more  particularly  applied  to 
structures  erected  for  the  purpose  of  con- 
veying the  water  of  distant  springs  across 
valleys,  for  the  supply  of  large  cities. 

The  largest  and  most  magnificent  aque- 
ducts, with  the  existence  of  which  we 
are  acquainted,  were  the  work  of  the 
Romans ;  and  the  ruins  of  several  of 
them,  both  in  Italy  and  other  countries 
of  Europe,  remain  to  the  present  time 
monuments  of  the  power  and  industry 
of  that  enterprising  people.  The  aque- 
duct of  Appius  Claudius  was  the  most  an- 
cient, and  constructed  in  the  442d  year 
of  Eome.  It  conveyed  the  Aqua  Appia 
to  the  city,  from  a  distance  of  between 
7  and  8  miles,  by  a  deep  subterranean 
channel  of  more  than  11  miles  in  length. 
The  aqueduct  of  Quintus  Martius  was  a 
more  extraordinary  structure.  It  com- 
menced at  a  spring  33  miles  distant  from 
Rome,  made  a  circuit  of  three  miles,  and 
afterwards,  forming  a  vault  of  16  feet 
diameter,  it  ran  38  miles,  along  a  series 
of  arcades  at  an  elevation  of  70  English 
feet.  It  was  formed  of  three  distinct 
channels,  placed  one  above  the  other, 
conveying  water  from  three  different 
sources.  In  the  uppermost  flowed  the 
Aqua  Julia;  in  the  second,  the  Aqua 
Tepula :  and  in  the  undermost,  the 
Aqua  Martia.  The  Aqua  Virginia,  con- 
structed by  Agrippa,  passed  through  a 
tunnel  of  800  puces  in  length.  The 
Aqua  Claudia,  begun  by  Nero,  and  fin- 
ished by  Claudius,  conveyed  the  water 
from  a  distance  of  38  miles.  This  aque- 
duct formed  a  subterraneous  stream  of 
30  miles  in  length,  and  was  supported 
on  arcades  through  the  extent  of  7  miles ; 
•nd  such  was  the  solidity  of  its  construc- 


tion, that  it  continues  to  supply  the 
modern  city  with  water  to  the  present 
day.  The  waters  of  the  river  Anio  were 
also  condncted  to  Rome  by  two  different 
channels ;  the  first  was  carried  through 
an  extent  of  43  miles,  and  the  latter 
through  upwards  of  63  miles,  of  which 
6s  miles  formed  one  continued  series  of 
arches,  many  of  them  upwards  of  100 
feet  in  height.  Nine  great  aqueducts 
existed  at  Rome  at  the  commencement 
of  the  reign  of  Nerva.  Five  others  were 
constructed  by  that  emperor,  under  the 
superintendence  of  Julius  Frontinus ; 
and  it  appears  that  at  a  later  period  the 
number  amounted  to  twenty.  The  sup- 
ply of  water  furnished  by  these  different 
works  was  enormous.  "According  to 
the  enumeration  of  Frontinus,  the  nine 
earlier  aqueducts  delivered  every  day 
14,018  quinaria.  This  corresponds  to 
27,743,100  cubic  feet.  We  may  there- 
fore extend  the  supply,  when  all  the 
aqueducts  were  in  action,  to  the  enor- 
mous quantity  of  50,000,000  cubic  feet 
of  water.  Reckoning  the  population  of 
ancient  Rome  at  a  million,  which  it  pro- 
bably never  exceeded,  this  would  fur- 
nish no  less  than  50  cubic  feet  for  the 
daily  consumption  of  each  inhabitant." 

The  remains  of  some  Roman  aqueducts 
in  other  parts  of  Europe  give  evidence  of 
the  existence  of  works  on  a  still  more  mag- 
nificent scale  than  those  of  Rome.  Of 
these  the  aqueduct  of  Metz  was  one  of  the 
most  remarkable.  A  number  of  its  ar- 
cades still  remain.  It  extended  across 
the  Moselle,  a  river  of  very  considerable 
breadth  at  this  place,  and  conveyed  the 
water  of  the  Gorse  to  the  city  of  Metz. 
The  water  was  received  in  a  reservoir, 
whence  it  was  conducted  by  subterra- 
neous canals,  formed  of  hewn  stone,  and 
so  spacious  that  a  man  might  walk  in 
them  upright.  The  arches  appear  to 
have  been  50  in  number,  and  50  feet 
high  at  the  deepest  part.  Some  of  the 
middle  ones  have  been  swept  away  by 
the  descent  of  ice  down  the  river  ;  those 
at  the  extremities  still  remain  entire. 

The  aqueduct  of  Segovia,  in  Spain,  is 
in  a  stiff  more  perfect  state  than  that  of 
Metz.  About  150  of  its  arcades  remain, 
all  formed  of  large  stones  without  ce- 
ment. There  are  two  rows  of  arcades, 
the  one  above  the  other,  and  the  height 
of  the  edifice  is  about  100  feet,  passing 
over  the  greater  part  of  the  houses  of  the 
city. 

Aqueducts  have  been  constructed  in 
modern  times,  particularly  in  France, 
which  rival  those  of  the  ancient  Romans. 


arc] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


17 


One  of  the  most  remarkable  was  con- 
structed by  Louis  XIV.,  for  conveying 
the  waters  of  the  river  Eure  to  Ver- 
sailles. It  extends  about  4400  feet  in 
length,  or  nearly  seven-eighths  of  a  mile, 
and  is  upwards  of  200  feet  in  height.  It 
contains  242  arcades,  each  divided  into 
three  rows,  forming  in  all  726  arches  of 
50  feet  span.  The  introduction  of  cast- 
iron  pipes,  which  has  only  taken  place 
within  the  last  century,  has  superseded 
the  use  of  such  expensive  structures.  (See 
Ckoton  Aqueduct.) 

AQUEOUS  SOIL.  Agr.  and  Hort. 
Soil  naturally  abounding  in  water,  the  fluid 
being  supplied  by  springs  in  the  subsoil. 
AQUETTA.  (Ital.  little  water.)  A 
celebrated  poison  used  by  the  Romans 
under  the  pontificate  of  Alexander  VII. 
It  was  probably  a  preparation  of  arsenic, 
and  was  also  known  under  the  name  of 
aqua  Toff  ana,  from  a  woman  of  the  name 
of  Toffana,  who  prepared  it  at  Naples. 

ARAB.  The  Barbary  name  oi  Thuja 
articulata,  the  tree  whose  wood  is  chiefly 
used  by  the  Mahometans  of  Africa  for 
the  construction  of  their  mosques,  and 
whose  resin  is  the  sandarach  of  com- 
merce. 

ARBOR.  The  spindle  or  axis  which 
communicates  motion  to  the  other  parts 
of  a  machine. 

ARCH.  (Lat.  arcus,  a  low.)  In  build- 
ing, a  structure  of  stones  or  bricks,  or 
distinct  blocks  of  any  hard  material,  dis- 
posed in  a  bow-like  form,  and  support- 
ing one  another  by  their  mutual  pres- 
sure. In  describing  arches  some  techni- 
cal terms  are  made  use  of,  which  it  will 
be  convenient  to  define.  The  arch  itself 
is  formed  by  the  vouissoirs,  or  stones 
cut  into  the  shape  of  a  truncated  wedge, 
the  uppermost  of  which  at  C  is  called 
the  key-stone.  The  seams  or  planes,  in 
which  two  adjacent  voussoirs  are  united, 
are  called  the  joints  ;  the  solid  masonry, 
A  E  and  B  E,  against  which  the  extrem- 
ities of  the  arch  abut  or  rest,  are  called 


T  V 

H 

a    A.        m\W 

E               " \" 

B     b 

the  abutments  ;  and  the  line  from  which 
the  arch  springs  nt  A  a  B  o,  the  impost. 
The  lower  line  of  the  arch-stones,  ACB, 


is  the  intrados  or  soffit :  the  upper  line, 
the  extrados  or  back.  The  beginning  of 
the  arch  is  called  the  spring  ot  the  arch  ; 
the  middle,  the  crown  ;  the  parts  be- 
tween the  spring  and  the  crown,  the 
haunches.  The  distance  A  B  between 
the  upper  extremities  of  the  piers,  or  the 
springing  lines,  is  called  the  span,  and 
C  D  is  the  height  of  the  arch. 

There  is  considerable  difficulty  in  de- 
termining the  form  which  an  arch  ought 
to  have,  in  order  that  its  strength  may 
be  the  greatest  possible,  when  it  sustains 
a  load  in  addition  to  its  own  weight ;  in 
fact,  the  determination  cannot  be  accu- 
rately made,  unless  we  know  not  only 
the   weight   of  the   materials   the  arch 
has  to  support,  but  also  the  manner  in 
which  the  pressure  is  connected ;  that  is 
to  say,  unless  we  know  the  amount  and 
direction  of  the  pressure  on  every  point 
of  the  arch.     Supposing,  however,  that 
the  arch  has  to  sustain  only  its   own 
weight,  and  supposing  further,  that  the 
friction  of  the  arch-stones  is  reduced  to 
nothing,  a  relation  between  the  curve 
and  the  weight  of  the  voussoirs  may  be 
found  by  comparing  the  pressures  which 
are  exerted  on  the  different  joints.  Thus 
the   pressure  on  any  joint,  s  q  for  ex- 
ample, arises   from  the  weight  of  that 
portion  of  the  arch  which  is  between 
s  q  and  the  summit  C  H.    Now,  the  por- 
tion of  the  arch  C  q  s  H  is  sustained  by 
three  forces  :  the  pressure  on  the  joint 
s  q,  the  pressure  on  C  H,  and  its  own 
weight.      Let  *  q  be  prolonged  till  it 
meets  C  D  in  O,  and  let  n  be  its  inter- 
section with  A  B.     It  is  a  theorem  in 
statics,    that   when   a  body  is  held  in 
equilibrium  by  three   forces    balancing 
each  other,  these  forces  are  proportional 
to  the  three  sides  of  a  triangle  formed  by 
lines  respectively  perpendicular  to  the 
directions    of  the    forces.      The    three 
forces  sustaining  C  q  s  H  are,  therefore, 
proportional  to  the  sides  of  the  triangle 
O  L>  n  ;   for  the  pressure  on  s  q  acts  in 
the   direction    perpendicular  to  *  q  or 
O  n ;  the  pressure  on  C  H  is  perpendicu- 
lar to  D  O,  and  wDis  perpendicular  to 
the  direction  of  gravity.    The  pressure 
on  s  q  is,  therefore,  to  the  pressure  on 
C  II  as  n  D  to  D  O.    In  like  manner,  the 
voussoir  p  r  q  s  being  so  shaped  that 
r  p,  when  produced,  meets  OH  in  the 
point  O  ;   the  pressure  on  the  joint  r  p 
is  to  that  on  C  H,   as  m  D  to  D  O. 
Hence,  the  pressure  on  sqis,  to  the  pres- 
sure on  r  p  as  1)  »  to  D  m.     We  are 
thus  led  to  infer  that  the  voussoirs  ought 
to  increase  in  length,  from  the  key-stone 


18 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


L' 


to  the  piers,  proportionally  to  the  lines 
i)»,Dffl,  &c. ;  for  in  this  case,  the  sur- 
faces of  the  joints  heing  increased  in 
proportion  to  the  pressure  they  sustain, 
the  pressure  on  every  point  of  the  arch 
will  De  equal.  It  will  also  be  observed 
that  the  angle  n  O  D  is  equal  to  the 
angle  made  "by  a  tangent  to  the  curve  at 
<?,  and  the  horizontal  line  parallel  to 
A  B;  the  angle  m  0  D  equal  to  that 
made  by  the  tangent  at  p  and  the  hori- 
zontal line ;  and  the  radius  D  O  remain- 
ing constant,  D  n  is  the  tangent  of  the 
point  of  these  angles,  and  L>  m  of  the 
second;  hence  the" pressures  on  the  suc- 
cessive joints  are  proportional  to  the  dif- 
ferences of  the  tangents  of  the  arches 
reckoned  from  the  crown.  From  this 
property,  when  the  intrados  is  a  circle 
given  in  position,  and  the  depth  of  the 
key-stone  is  given,  the  curve  of  the  ex- 
trados  may  be  found.  When  the  weights 
of  the  voussoirs  are  all  equal,  the  arch  of 
equilibration  is  a  catenarian  curve,  or  a 
curve  having  the  form  which  a  flexible 
chain  of  uniform  thickness  would  as- 
sume if  hanging  freely,  the  extremities 
being  suspended  from  "fixed  points. 

Such  is  the  form  which  theory  shows 
to  be  the  best  adapted  to  give  strength 
to  an  arch,  on  the  supposition  that  there 
is  no  superincumbent  pressure.  But  it 
seldom  if  ever  happens  that  this  is  the 
case,  and  therefore  it  is  entirely  unneces- 
sary, in  the  actual  construction  of  an 
arch,  to  adhere  closely  to  the  form  deter- 
mined on  the  above  supposition.  In- 
deed, on  account  of  the  friction  of  the 
materials  and  the  adhesion  of  the  cement, 
the  form  of  the  fu*ch,  within  certain  lim- 
its, is  quite  immaterial,  for  the  deviation 
from  the  form  of  equilibration  must  be 
very  considerable  before  any  danger  can 
arise  from  the  slipping  of  the  arch-stones. 
The  Roman  arches  are  almost  semi-cir- 
cles, yet  they  have  lasted  many  centuries. 
The  arch  is  not  found  in  an  Egyptian 
building  nor  in  the  earlier  Greek.*  The 
Romans  understood  the  advantage  of  the 
arch  from  an  early  period.  The  cloaca 
maxima  is  of  the  age  of  the  Tarquins. 
The  Etruscans  originated  the  arched 
dome,  and  the  Romans  first  applied  the 
arch  to  bridges    and  aqueducts.      The 

Sointed  arch  was  introduced  in  the  mid- 
le  ages  by  the  associated  architects, 
who  have  left  extant  the  noblest  piles  of 
architecture,  and  in  which  the  arch  is 
multiplied  and  combined  in  all  possible 
ways.     (See  Beidgk.) 

ARCHIL.  OrghU.  Cudbear.  A  violet 
dye  obtained  from  many  species  of  li- 


chen, chiefly  the  BocelXa  tinctoria,  fuci- 
formis,  which  grow  in  large  quantities 
in  the  Canary  Islands.  Archil  is  chiefly 
used  to  improve  the  dye  of  other  colors, 
and  to  give  richness  and  brilliancy  to 
them.  The  lichens  grow  on  rocks  near 
the  sea ;  they  are  collected  and  fermented 
with  ammoniacal  liquor,  which  brinsrs  out 
the  color ;  the  mass  is  then  pressed  out, 
and  made  into  a  paste  with  chalk  and 
plaster  of  Paris.  It  is  then  archil.  The 
coloring  matter  is  due  to  the  chemical 
principle  orcine.  In  silk-dyeing  archil 
produces  the  lilac  color;  it  economises 
the  use  of  indigo  on  woollen  cloth.  It 
also  stains  marble  violet. 

AREOMETER.  An  instrument  for 
measuring  the  density  or  specific  gravity 
of  liquids. 

ARGAND.     {See  Lamps.) 

ARGIL.  Argillaceous  earth.  A  name 
applied  to  the  earth  of  clay,  termed  alu- 
mina, from  its  being  found  so  pure  in 
alum. 

ARGOL.    The  tartar  of  wine. 

ARICINA.  An  alkaloid  discovered  by 
Pelletier  in  a  species  of  cinchona. 

ARRACK.  A  spirituous  liquor  ob- 
tained by  distilling  termented  rice  or  the 
juice  of  the  cocoa-nut. 

ARROW  ROOT.  The  commercial 
name  of  the  starch  obtained  by  washing 
the  grated  root  of  the  maranta  arundi- 
nacea,  which  it  yields  to  the  amount  of 
twenty -five  to  thirty  per  cent.  It  is 
sometimes  adulterated  with  potato  starch, 
and  the  fraud  is  not  easily  detected  ;  it, 
however,  gives  a  disagreeable  flavor  and 
smell,  like  that  of  tlie  raw  potato,  and 
forms  a  less  firm  jelly  with  hot  water 
that  when  the  arrow  root  is  genuine. 

The  roots  when  one  year  old  are  dug 
and  washed;   they  are  grated,  and  the 

Eulpy  matter  agitated  with  water.  The 
bres  are  collected  by  hand  and  removed, 
and  the  milky  liquor  strained  through  a 
sieve  and  left  to  settle.  The  white  pasty 
mass  is  the  arrow  root,  which  is  perhaps 
again  washed,  then  dried,  and  packed 
for  exportation.  The  arrow  root  of  Ber- 
muda is  considered  the  finest.  Tous  le 
mois,  or  starch,  is  obtained  from  the  roots 
of  canna  coccinea ;  Otaheite  arrow  root 
from  the  tacca  pinnatifida.  The  East  In- 
dian from  a  curcuma,  and  the  Portland 
arrow  root  from  arum  maculatum  are  oc- 
casionally used  as  substitutes.  The 
grains  of  arrow  root  are  in  the  form  of 
small  globes  or  spheres  when  viewed  by 
the  microscope. 

ARSENICT.  A  very  soft,  brittle,  and 
eminently  poisonous  metal,  of  a  steel 


ARS] 


CYCLOPEDIA   OF   THE    USEFUL   ARTS. 


19 


gray  color :  its  sp.  gr.  5*7.  It  volatilizes, 
exhaling  a  strong  odor  of  garlic,  before 
it  fuses,  at  a  temperature  ot  365°  F.,  and 
is  easily  inflammable.  It  combines  with 
oxygen  in  two  proportions ;  and  as  both 
compounds  are  sour,  and  form  salts  with 
bases,  they  have  been  termed  arsenious 
and  arsenic  acids:  the  former  is  com- 
posed of  38  arsenic  and  12  oxygen,  and 
the  hitter  of  38  arsenic  and  20  oxygen.  Ar- 
senious acid  is  more  commonly  known 
under  the  name  of  white  arsenic^  and  is 
the  usual  state  in  which  this  poison  oc- 
curs in  commerce ;  it  is  obtained  during 
the  extraction  of  several  of  the  metals 
from  their  ores,  and  is  a  white,  brittle, 
semi-transparent  substance,  having  little 
taste,  but  is  virulently  poisonous.  Its 
sp.  gr.  is  3-7.  It  forms  a  dull  white 
powder,  and  it  is  in  this  form  that  it  is 
usually  sold.  When  heated  in  the  flame 
of  a  candle,  it  rises  in  the  form  of  a 
white  poisonous  vapor,  and  exhales,  in 
consequence  of  its  partial  reduction,  a 
strong  garlicky  smell :  1000  parts  of  cold 
water  dissolve  about  2i  of  white  arse- 
nic ;  but  when  the  water  is  boiled  with 
the  arsenic,  1000  parts  take  up  between 
77  and  78  ;  and  this  solution,  after  stand- 
ing a  few  days,  deposits  rather  more 
than  half  of  the  white  arsenic,  in  the 
form  of  small  crystals,  retaining  about 
30  grains  in  permanent  solution.  White 
arsenic  dissolves  in  the  alkalies,  and  com- 
bines with  the  metallic  oxides,  forming  a 
class  of  salts  called  arsenites :  they  are 
all  poisonous.  Of  these  the  arsenite  of 
potash  is  used  in  medicine,  under  the 
name  of  Fowler's  mineral  solution  :  it  is 
employed  in  very  small  doses  in  the  cure 
of  agues,  and  is  an  effective  remedy,  but 
requires  much  care  in  its  administration. 
When  white  arsenic  is  taken  as  a  poi- 
son,— that  is,  in  large  doses,  it  produces 
violent  spasmodic  pains  of  the  stomach 
and  bowels,  attended  by  a  sense  of  heat, 
and  constriction  in  the  mouth  and  throat ; 
an  increased  flow  of  saliva,  tightness 
about  the  head,  itching  of  the  face  and 
neck,  and  nausea.  These  symptoms  are 
succeeded  by  vomiting  and  purging  and 
excruciating  pains  ;  the  pulse  at  "first  full, 
hard,  and  frequent,  sinks  and  becomes 
irregularly  feeble,  and  clamminess  of  the 
skin,  cold  sweats,  purple  spots,  and  con- 
vulsions, precede  death ;  or  if  the  pa- 
tient escape  this  catastrophe,  it  often 
happens  that  hectic  fever,  paralysis,  and 
mental  and  bodily  debility,  attend  him 
for  the  remainder  of  his  days.  It  is 
often  said  that  the  bodies  of  persons 
poisoned  by  arsenic  are  very  prone  to 


putrefaction;  but  this  does  not  appear 
to  be  always  the  case.  After  death  the 
stomach  and  bowels  are  usually  found 
inflamed,  but  often  only  slightly  so ;  and 
it  appears  from  Sir  B.  Brodie's  observa- 
tions, that  this  poison  kills  by  some  pe- 
culiar action  upon  the  heart  and  nervous 
system.  The  treatment  of  persons  thus 
poisoned  consists  in  promoting  the  vo- 
moting  by  an  emetic,  composed  of  a  so- 
lution of  20  grains  of  sulphate  of  zinc  in 
two  ounces  of  water,  aided  by  copious 
draughts  of  warm  barley-water  or  gruel ; 
but  the  most  effective  means  of  getting 
rid  of  the  arsenic,  is  by  the  use  of  the 
stomach-pump,  which,  wlien  immediately 
resorted  to,  has  often  saved  the  patient. 
The  after-treatment  requires  much  cir- 
cumspection. 

The  only  ready  means  of  ascertaining 
the  presence  of  white  arsenic  is  by  heat- 
ing the  suspected  substance  upon  a  red- 
hot  coal,  or  in  the  flame  of  a  candle  or 
spirit  lamp,  when  it  will  exhale  the  pe- 
culiar arsenical  odor  resembling  that  of 
garlic ;  but  the  treatment  of  persons  poi- 
soned by  arsenic,  and  its  detection  in 
doubtful  cases,  must  be  left  to  the  medi- 
cal man  and  the  chemist.  It  is  impossi- 
ble too  strongly  to  represent  the  evil 
which  results  from  the  unfettered  sale  of 
arsenic,  and  from  the  unwarrantable  use 
of  it  as  a  poison  for  rats,  and  as  a  veteri- 
nary remedy,  for  it  is  thus  that  it  finds 
its  way  into  culinary  vessels,  gets  acci- 
dentally mixed  with  articles  of  iood,  and 
that  bottles  which  have  contained  it  are 
used  for  beer,  wine,  vinegar,  or  medi- 
cine :  its  sale  should  be  rigidly  prohibited. 

This  metal  occurs  native  in  the  state 
of  white  oxide  (arsenious  acid) ;  also  with 
sulphur,  known  as  yellow  and  red  ar- 
senic. It  is  associated  with  a  great  many 
metallic  ores,  but  chiefly  with  cobalt  in 
Silesia,  in  Europe.  It  is  separated  from 
that  metal  by  roasting,  and  the  arsenic  is 
obtained  as  white  oxide.  Arsenic  enters 
into  the  composition  of  flint  glass,  the 
body  of  which  it  whitens  and  purifies : 
it  is  apt,  however,  to  make  the  glass 
milky.  It  is  used  in  candle-making,  to 
remove  the  crystalline  tendency  of  stea- 
rine.  It  is  also  used  to  destroy  rats  and 
vermin.  It  has  a  remarkable  tendency 
to  preserve  the  parts  of  the  animal  body 
it  is  brought  into  contact  with,  and  hence 
it  has  been  used  in  the  stuffing  of  birds 
and  the  preservation  of  other  objects  of 
natural  history.  To  make  an  appropriate 
preparation  Dumas  gives  the  lollowing 
recipe : 

White  soap  and  arsenious  acid,  of  each 


20 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[AM 


100  parts ;  carbonate  of  potash,  30  parts ; 
camphor,  15  parts ;  quicklime,  12  parts. 
The  potash,  soap,  and  lime,  are  melted 
together;^  then  the  arsenic  is  added. 
The  camphor  is  dissolved  in  alcohol,  and 
added  in  when  the  mass  is  cold.  Some 
of  this  soap  mixed  with  water  is  laid  on 
with  a  brusn.  Arsenic  alloyed  with  me- 
tals makes  them  more  brittle  and  fusi- 
ble :  with  copper  it  forms  white  tombac. 

Arsenic  acid  is  more  soluble  and  sour, 
but  equally  poisonous  with  the  arsenious 
acid.  Its  salts  are  called  arseniates,  and 
the  arseniate  of  potash  obtained  by  de- 
flagrating a  mixture  of  white  arsenic  and 
nitrate  of  potash  is  occasionally  used  in 
medicine :  it  is  the  active  ingredient  in 
the  tasteless  ague  drop.  It  is  also  used 
in  calico-printing  as  a  resist  paste  laid  on 
by  blocks  to  prevent  the  mordant  acting 
on  the  cloth  in  those  places. 

ARTESIAN  FOUNTAINS,  or  AR- 
TESIAN WELLS.  (Fr.  Puits  Artesiens.) 
Vertical  perforations  of  the  exterior  crust 
of  the  earth,  of  small  diameter,  and  fre- 
quently of  great  depth,  through  which 
subterraneous  water  arises  to  the  sur- 
face, often  forming  abundant  and  ele- 
vated jets.  The  name  Artesian  is  derived 
from  Artois,  a  province  of  France,  where 
especial  attention  has  been  given  to  this 
means  of  obtaining  water  ;  but  it  ap- 
pears, from  sufficient  historical  evidence, 
that  wells  of  this  kind  were  perfectly 
well  known  to  the  ancients.  Niebuhr 
cites  a  passage  from  Olympiadorus,  who 
flourished  at  Alexandria  about  the  mid- 
dle of  the  sixth  century,  in  which  it  is 
stated  that  when  wells"  are  dug  in  the 
Oasis  to  the  depth  of  two  hundred,  three 
hundred,  or  sometimes  five  hundred 
yards,  rivers  of  water  gush  out  from 
their  orifices,  of  which  the  agriculturists 
take  advantage  to  irrigate  their  fields. 
The  oldest  Artesian  well  known  to  exist 
in  France  is  in  the  ancient  convent  of  the 
Chartreux,  at  Lillers  in  Artois.  It  is  said 
to  have  been  made  in  1126.  Others  exist 
at  Stuttgart,  of  great  antiquity,  though 
their  dates  cannot  be  fixed  with  pre- 
cision. The  inhabitants  of  the  great  de- 
sert of  Sahara  appear  also  to  have  been 
long  acquainted  with  this  mode  of  ob- 
taining water,  and  the  Chinese  are  said 
(but  the  truth  of  the  statement  is  ques- 
tionable) to  have  practised  it  for  thou- 
sands of  years. 

Various  conjectures  have  been  made 
as  to  the  source  of  the  water  which  comes 
from  the  Artesian  wells.  It  was  long 
believed  that  the  water  of  the  sea  must 
necessarily  penetrate  by  way  of  infiltra- 


tion into  the  interior  of  the  continents, 
and  at  length  form  large  bodies  of  sub- 
terraneous waters,  which,  excepting  for 
capillary  influences,  would  not  rise  above 
the  general  level  of  the  ocean.  Another 
opinion,  maintained  by  Aristotle,  Seneca, 
Cardan,  and  even  Descartes,  was,  that 
the  subterraneous  water,  from  which  the 
sources  of  rivers  and  springs  are  sup- 
plied, is  the  product  of  the  condensation 
of  aqueous  vapors  ascending  from  the 
interior  parts  ot  the  earth  in  consequence 
of  the  central  heat.  But  these  hypo- 
theses are  founded  on  mere  conjecture, 
unsupported  by  the  slightest  evidence, 
and  consequently  merit  no  attention. 
The  simplest  and  most  natural  explana- 
tion is,  that  the  water  of  ordinary  wells, 
of  Artesian  fountains  and  rivers,  is  sup- 
plied by  the  rain  which  falls  on  the  sur- 
face at  a  higher  elevation,  and  which 
penetrates  through  the  pores  and  fissures 
of  the  ground  till  it  meets  with  some  im- 
permeable stratum,  or  is  collected  in 
subterranean  reservoirs.  It  has  been 
objected  that  springs  are  sometimes  situ- 
ated on  or  near  the  summits  of  moun- 
tains, which  could  not  be  supplied  in 
this  way ;  but  on  an  attentive  examina- 
tion of  all  the  circumstances — that  is  to 
say,  on  measuring  accurately  the  extent 
of  surface  at  a  greater  elevation  than  the 
spring,  and  comparing  it  with  the  quan- 
tity of  rain  that  falls  annually  in  the 
same  climate,  it  has  been  found,  in  every 
instance,  that  the  aqueous  deposition 
from  the  atmosphere  greatly  exceeds  the 
supply  from  the  spring.  It  is  computed 
that  not  more  than  a  third  part  of  the 
rain  which  falls  in  the  valley  of  the  Seino 
is  conveyed  to  the  sea  by  the  river ;  the 
remaining  two-thirds  support  vegetation, 
supply  fountains  and  springs,  or  are  re- 
turned to  the  atmosphere  by  evapora- 
tion. The  immense  bodies  of  water  which 
some  continental  rivers  roll  towards  the 
ocean  are  but  a  small  part  of  the  rain 
which  falls  in  the  surrounding  countries. 

The  average  fall  of  rain  in  these  lati- 
tudes is  about  40  inches  of  rain,  or  about 
3,500  tons  of  water  deposited  in  the 
course  of  the  year  on  every  acre.  In 
sandy  districts  this  rain-water  penetrates 
like  as  through  a  sieve.  In  mines  sunk 
in  limestone  rocks  the  water  increases 
in  the  galleries  very  remarkably  after  a 
fall  of  rain. 

Assuming,  then,  that  the  subterra- 
neous water  is  supplied  from  atmospher- 
ical deposition,  it  remains  to  be  explained 
how  it  arrives  at  the  situation  it  occupies 
in  the  interior  of  the  earth,  and  by  what 


art] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


21 


forces  it  is  raised  from  great  depths  to 
the  surface. 

All  persons  who  have  paid  the  slight- 
est attention  to  geology  are  aware  that  in 
stratified  countries  (and  it  is  in  such 
only  that  Artesian  wells  exist)  different 
beds  of  rocks  are  superposed  on  one 
another,  and  ranged  in  a  certain  constant 
order.  The  strata  sometimes  follow  a 
horizontal  direction  for  a  considerable 
extent  of  country ;  at  other  places  they 
are  inclined,  and  even  placed  perpen- 
dicularly to  the  horizon,  naving  the  ap- 
pearance of  having  been  bent  and  burst 
through  by  the  action  of  a  powerful  force 
from  beneath.  In  those  cases  the  edges 
of  the  strata  arc  often  exposed,  especially 
on  the  summits  and  flanks  of  hills,  to  the 
action  of  the  atmosphere. 

The  following  diagram  illustrates  this  : 
it  represents  a  basin  composed  of  perme- 


able strata  {a  a  a)  separated  by  imper- 
meable layers  (b  o  h).  The  water  which 
falls  on  the  edges  of  a  on  the  side  x  will 
sink  down  and  fill  the  beds  until  the 
water  rises  on  the  other  side,  and  has  a 
tendency  to  run  out  at  A.  If  tubes  be 
sunk  in  the  middle,  as  at  c  d  <?/,  the 
water  will  flow  up  these  tubes  until  it 
attains  the  level  of  the  beds  of  clay  at  b  ; 
and  as  the  ground  at  the  place  of  sinking 
is  on  a  lower  level,  the  water  will  rise  in 
the  tube  considerably  above  the  surface, 
and  will  be  thrown  up  with  great  force. 

Between  the  strata  are  frequently  found 
beds  of  permeable  sand,  through  which 
water,  coming  in  contact  with  them,  must 
necessarily  pass,  first,  through  the  in- 
clined part  by  virtue  of  its  specific  gra- 
vity, and  then  in  the  horizontal  branches, 
by  virtue  of  the  pressure  of  the  water 
remaining  in  the  elevated  portions  of  the 
strata.  In  this  manner  the  water  insinu- 
ates itself  between  the  different  strata ; 
and  hence  we  may  expect  that  in  locali- 
ties where  the  tertiary  stratification  pre- 
vails, as  many  distinct  sources  of  subter- 
raneous water  will  be  met  with  in  pene- 
trating perpendicularly  through  the  sur- 
face, as  there  are  distinct  layers  of  a 
sandy  or  gravelly  nature  reposing  on  im- 
permeable strata.    This  consequence  of 


the  theory  is  perfectly  confirmed  by  ex- 
perience. M.  Arago  mentions,  that  in 
digging  for  coal  near  St.  Nicholas  d'Alier 
mont,  a  short  distance  from  Dieppe, 
seven  distinct  and  copious  sources  of 
water  were  found,  the  respective  depths 
of  which  were  :  1st,  between  80  and  100 
feet ;  2d,  328  feet ;  3d,  from  570  to  590 
feet ;  4th,  from  690  to  710  feet ;  5th,  820 
feet ;  6th,  940  feet ;  7th,  1090  feet ;  and 
the  occasional  force  of  each  source  wM 
very  great.  Similar  occurrences  are  fre- 
quent in  the  neighborhood  of  London, 
and  are  familiar  to  all  miners.  But  it  is 
not  enough  that  the  structure  of  the 
country  is  such  that  water  can  percolate 
between  different  strata ;  the  phenomena 
of  Artesian  fountains  could  not  be  ex- 
plained without  supposing  it  to  be  col- 
lected in  large  quantities,  and  forming 
subterranean  reservoirs  of  immense  ex- 
tent. That  such  reservoirs  exist,  no 
doubt  can  be  entertained.  The  cele- 
brated fountain  of  Vaucluse  sends  forth 
at  all  times  a  stream  of  water  sufficient 
to  form  a  considerable  river.  Even  in 
the  driest  seasons,  when  the  water  is 
least  plentiful,  it  produces  5780  cubic  feet 
per  minute.  After  great  rains,  its  pro- 
duct is  thrice  as  great.  The  mean  quan- 
tity emitted  is  9360  cubic  feet  per  minute, 
or  about  5032  millions  of  cubic  feet  in  a 
year.  Many  other  examples  of  the  same 
kind  might  be  cited ;  showing  that  water 
must  not  only  be  collected  in  subter- 
raneous cavities  in  immense  quantities, 
but  that  it  also  passes  freely  from  one 
place  to  another.  In  fact,  the  disposition 
of  the  rocks  in  strata  permits  the  water 
to  be  collected  under  the  surface,  and  to 
be  conveyed  without  waste,  as  if  in  close 
pipes. 

According  to  the  view  which  has  now 
been  taken  of  the  manner  in  which  sub- 
terraneous water  is  collected,  its  eleva- 
tion to  the  surface  through  a  natural  fis- 
sure or  artificial  perforation  is  a  simple 
result  of  hydrostatic  pressure.  Generally 
speaking,  it  is  only  on  the  acclivities  of 
hills,  or  in  elevated  places,  that  the  edges 
of  the  strata  are  exposed,  and  where, 
consequently,  the  rain  water  can  be  re- 
ceived under  beds  of  impermeable  ma- 
terials. Conceive  two  strata  of  clay,  or 
rocks,  as  a  and  J,  having  a  bed  of  sand 
or  other  matter  permeable  to  water  inter- 
posed, and  suppose  that  d  is  the  place 
where  the  edges  of  the  strata  drop  out, 
or  where  a  fissure  allows  a  free  entrance 
of  the  water  to  the  permeable  stratum. 
The  water  at  first  descends  through  the 
effect  of  gravity ;  it  then  passes  along  to- 


22 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


wards  b  in  consequence  of  the  pressure 
exercised  by  the  superior  part  of  the 


column  near  d.  Now  suppose  a  perfora- 
tion to  be  made  at  e,  and  continued  till  it 
reaches  through  the  stratum  a,  the  water 
will  naturally  continue  to  rise  till  it  gains 
the  same  altitude  as  d,  or  at  least  till  it 
reaches  the  surface,  if  below  that  alti- 
tude. The  water  in  fact  between  the 
two  impermeable  strata  is  in  the  same 
circumstances  as  in  an  artificial  pipe ;  and 
if  the  surface  of  the  ground  at  e  is  con- 
siderably lower  than  a,  the  ascensional 
force  may  be  sufficient  to  cause  a  con- 
siderable jet. 

Some  Artesian  fountains,  for  example 
that  at  Lillers  in  Artois,  are  situated  in 
the  middle  of  immense  plains,  where  not 
the  most  insignificant  hill  is  to  be  seen  on 
any  side.  In  such  cases  it  may  be  inquired 
where  we  are  to  look  for  those  hydrosta- 
tic columns  whose  pressure  causes  the 
rise  of  the  subterraneous  water  to  the 
level  of  the  lowest  points  ?  The  answer 
is  obvious :  we  must  suppose  them  placed 
beyond  the  limits  of  view ;  at  the  dis- 
tance of  50,  100,  or  200  miles,  or  even  at 
a  greater  distance.  The  necessity  of  sup- 
posing the  existence  of  a  subterraneous 
liquid  column  of  two  or  three  hundred 
miles  of  extent,  cannot  appear  a  serious 
objection,  when  it  is  considered  that  the 
same  geological  structure  has  been  found 
to  prevail  sometimes  over  even  a  much 
greater  extent  of  country. 

The  water  which  rises  in  Artesian  wells 
of  great  depth  is  remarkably  warm,  and 
is  used  for  heating  greenhouses  and 
dwellings,  and  for  washing  purposes. 

There  are  no  geologicalcapabilities  in 
this  country  for  the  sinking  of  Artesian 
wells  to  any  depth,  or  for  any  certainty; 
they  are  chiefly  sunk  in  beds  of  the  up- 
per secondary  formation,  which  have  not 
at  all  the  same  extent  of  development  on 
this  as  on  the  Eastern  hemisphere. 

The  fountains  in  the  parks  of  New 
York  and  other  cities,  act  upon  the  same 

Principle  as  Artesian  wells :  thus  in  New 
'ork,  the  water  which  is  thrown  up  in 
Union  Square  and  the  Park  has  a  ten- 
dency to  rise  to  the  height  of  the  surface 


of  the  water  in  the  lower  distributing 
reservoir. 

ASBESTUS— Amianthus.— A  mineral 
in  which  the  long-needle  crystals  have  a 
fibrous  appearance.  It  is  a  variety  of 
hornblend  or  tremolite,  so  soft  in  tex*ture 
as  to  be  spun  and  woven  in  flax,  and  from 
its  incombustible  nature,  the  cloth  made 
of  it  may  be  cleansed  when  dirty  by 
burning  it.  The  ancients  wrapped  "their 
dead  in  this  cloth  before  burning,  to  keep 
the  ashes  from  mixing  with  the  fire.  The 
Greenlanders  use  it  for  the  wicks  of 
lamps.  In  the  Pyrenees,  girdles  are 
made  of  it,  which  are  much  prized. 
There  are  many  varieties,  as  ligniform,  or 
woodlikt  asbest,  which  is  so  hard  as  to  be 
cut  and  polished  •  the  fibres  are  less  close 
in  mountain  leather,  and  rock  cork  is  so 
light  as  to  float  upon  water.  Asbestus  is 
made  up  of  silica,  magnesia,  lime  and  iron. 

ASHLAR.  In  architecture,  common 
freestones,  as  they  are  brought  rough  and 
chipped,  or  detached  from  the  quarry,  of 
different  lengths  and  thicknesses.  Their 
usual  thickness  is  nine  inches. 

ASHLERING.  In  architecture,  the 
upright  timber  or  quarters  towards  the 
rooms,  or  inwards  in  garrets,  by  which 
the  slope  of  the  roof  is  concealed, — some- 
times it  is  only  two  or  three  feet  high, 
and  sometimes  the  whole  height  of  the 
room. 

ASPHALTUM.  A  black  brittle  bitu- 
men, very  fusible  and  inflammable :  it  is 
soluble  in  naptha,  and  forms  a  good  var- 
nish. It  is  found  upon  the  surface  and 
banks  of  the  Dead  Sea  (hence  called  As- 
phaltic  Lake),  and  in  large  quantity  in 
Trinidad  and  Barbadoes.  The  ancients 
employed  it  in  some  of  their  cements,  and 
it  was'used  also  in  the  art  of  embalming. 
It  probably  exists  on  this  continent,  in 
Nova  Scotia  and  New  Brunswick,  and  in 
South  America,  at  Coxitambo.  It  has  of 
late  been  much  used  as  a  cement-paving, 
for  which  purpose  the  asphalte  is  melted, 
and  mixed  with  sand  and  carbonate  of 
lime,  and  run  into  moulds,  forming 
blocks,  weighing  above  100  lbs.  each. 
For  roads,  it  is  spread  upon  a  thick  layer 
of  concrete ;  it  is  also  used  for  lining  cis- 
terns and  rendering  surfaces  waterproof. 
This  cement  has  the  advantage  of  oeing 
very  easy  of  repair,  it  being  only  neces- 
sary to  warm  the  imperfect  part,  and  cut 
it  away  with  the  knife,  it  may  then  be 
melted"  and  poured  into  the  deficiency, 
and  made  to  assume  the  proper  shape. 
The  asphalte  rock  is  a  lime  rock,  contain- 
ing 80  per  cent,  of  carbonate  of  lime  and 
20  per  cent,  of  bitumen. 


ATO] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


23 


A  branch  of 
a  process  b; 


N 


r  Mb   ' 


ASSAY,  ASSAYING, 
chemical  analysis.  It  is  a  process  by 
which  the  quality  of  gold  or  silver  bul- 
lion, trinkets,  plate  and  coin  is  ascertained 
with  precision,  or  by  which  the  quantity 
of  either  of  these  precious  metals  may  be 
determined  in  an  alloy.  It  is  now  ex- 
tended to  determine  the  quantity  of  pla- 
tinum and  palladium  in  certain  bullion 
and  gold  dust  from  Brazil.  The  art  of 
assaying  depends  upon  the  fact  that  gold 
and  silver  have  but  a  very  feeble  affinity 
for  oxygen  in  comparison  with  copper  and 
tin,  and  these  latter,  when  oxydized,  unite 
with  lead,  and  sink  with  it  into  any  por- 
ous earthen  vessel.  This  vessel,  or  cupel, 
may  be  made  of  leached  wood-ashes,  or 
of  burned  bones,  well  powdered. 

Cupellation,  as  this  operation  is  called, 
fig.  1.  is  usually  carried  on  in  a 
small  furnace,  capable  of 
being  heated  so  as  to  melt 
gold.  In  the  annexed  cut, 
fig.  1  represents  the  fur- 
c^Q-j=3  nace,  which  is  lighted  with 
iQi  charcoal  when  an  assay  is 
C^^Tt3  t0  De  made. 

In  the  middle  of  this  fur- 
nace when  heated,  is  placed 
an  earthen  vessel  called  a 
muffle,  fig.  2  (comparatively 
enlarged),  which  is  of  an 
oven   form,  vaulted  above 
and  flat  below,  open  at  one 
end  and  closed  elsewhere,  except  by  a 
few  narrow  slits  at  the  top  and  sides.  The 
fig.  2.  body  of  the 

muffle  is 
surrounded 
with  coals, 
and  before 
cupellation 
is  gradually 
heated  to  a  cherry  red.  Its  use  is  to 
protect  the  small  cupels  ranged  on  its 
floor  from  any  impurities  of  fuel,  and  at 
the  same  time  to  afford  it  plenty  of  air 
to  oxydize  the  metals.  The  cupels  are 
little  bone  dishes,  made  of  the  ma- 
terials stated  previously  moistened 
into  a  paste,  and  pressed  into  a 
shape  by  a  cast-iron  mould,  which 
fig.  3.  represents. 

From  12  to  35  grains  is  the  pro- 
per quantity  of  alloy  to  be  weighed 
out  for  examination.  It  is  wrap- 
ped up  in  lead-foil  or  paper,  and 
surrounded  by  the  thin  plate  of 
lead,  they  are  then  placed  upon  the 
cupel  and  laid  in  the  muffle  iying  in 
the  furnace,  heated  red  hot,  when 


they  immediately  melt.  The  lead  oxidizes, 
and  the  oxide  of  lead  formed,  melts  and 
runs  down  the  sides  of  the  mass  into  the 
body  of  the  cupel.  The  button  of  alloy 
becomes  smaller  and  brighter,  and  ulti- 
mately leaves  the  silver  iriastate  of  great 
purity.  The  quantity  of  lead  necessary 
to  carry  out  this  experiment  is  a  matter 
of  nicety ;  if  too  much  be  used,  some 
silver  will  be  lost ;  if  too  little,  the  cop- 

fier  will  not  be  removed  from  the  alloy. 
n  every  assay,  by  this  way,  a  little  silver 
does  seem  to  be  lost.  The  operation  be- 
ing now  finished,  the  cupel  is  cooled,  and 
the  button  of  pure  metal  weighed.  The 
difference  between  it  and  the  original 
weight  gives  the  amount  of  alloy  present. 
A  gold  assay  is  more  complex  than  a 
silver  one.  The  copper  alloyed  with  gold 
cannot  well  be  separated  by  heat  alone  : 
some  silver  requires  to  be  added  for  this 
purpose,  which  entails  the  necessity  of 
a  subsequent  operation  to  remove  the 
silver.  In  coins  and  manufacture,  gold 
is  often  mixed  with  silver,  and  the  opera- 
tion of  separating  them  is  termed partvng, 
which  consists  in  treating  the  mass  with 
dilute  nitric  acid,  which  dissolves  the  sil- 
ver out  and  leaves  the  gold.  If  the 
amount  of  silver  be  small,  it  is  necessary 
to  add  some  silver  to  it,  for  in  that  case 
the  gold  preponderating,  the  silver  is 
protected  from  the  action  of  the  acid. 
After  the  acid  has  removed  all  the  silver 
and  copper,  the  insoluble  metal  remain- 
ing is  placed  on  the  cupel  and  heated  in 
the  furnace,  it  is  then  cooled  and  weighed, 
and  the  weight  indicates  the  absolute 
quantity  of  gold  in  the  sample. 

Assaying  is  extended  to  copper  ores,  to 
determine  the  value  of  a  sample,  as  to 
the  amount  it  should  produce  in  the 
smelting  furnace,  or  whe'ner  it  be  worth 
working.  Assays  may  be  conducted  by 
the  assistance  of  heat  and  fluxes,  or  in 
the  dry  way  as  it  is  termed,  or  else  in 
the  moist  way,  as  by  acids  or  other  re- 
agents ;  the  former  is  the  readier  mode, 
the  latter  the  more  correct.  Berthier's 
work  on  "  Assays  by  the  Dry  Way,"  and 
Mitchel's  "Manual  of  Practical  Assaying" 
maybe  consulted  for  further  information. 
ATOMS,  or  Atomic  Wkights,  are  the 
original  quantities  in  which  bodies  either 
simple  or  compound  combine  with  each 
other,  referred  to  a  common  body  taken 
as  unity.  Oxygen  is  taken  as  the  stand- 
ard by  some,  and  hydrogen  by  others. 
The  atomic  weight  of  a  substance  is  its 
lowest  combining  figure  :  thus  if  oxygen 
unites  with  bodies  in  several  proportions, 
the  lowest  of  which  is  8,  then  8  is  said 


24 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


V 


to  be  the  atomic  weight  of  oxygen ;  it  is 
better  termed  its  equivalent,  or  its  com- 
bining proportion.  A  knowledge  of 
chemical  equivalents,  or  atomic  weights, 
is  of  great  use  to  the  manufacturer,  as  it 
informs  him  in  many  cases  of  the  proper 
quantity  of  one  substance  to  be  mixed 
with  another,  and  thus  saves  him  from 
waste  or  loss.  The  subjoined  is  a  list  of 
the  equivalents  of  the  elementary  bodies 
from  which  the  atomic  weights  of  many 
of  the  compounds  may  be  calculated. 
Those  substances  which  have  no  figures 
attached,  have  not  had  the  equivalents 
correctly  determined : 

Hydrogen, 1 

Oxygen, 8 

Carbon, 6 

Boron, 11 

Phosphorus, 32 

Sulphur, 16 

Selenium, 40 

Iodine, 126 

Bromine, 78 

Chlorine, 35 

Fluorine, 19 

Nitrogen, 14 

Potassium, 40 

Sodium, 24 

Lithium, 7 

Barium, 69 

Strontium, 44 

Calcium, 20 

Magnesium, 12 

Lanthanum, 44 

Cerium, 46 

Didymium, 

Erbiu  m,. 

Terbium, 

Yttrium, 32 

Glucinum, 5 

Aluminum, 14 

Thorium, ., 60 

Zirconium, 23 

Silicium, 15 

Titanium, 24 

Tantalium, 185 

Niobium, 

Pelopium 

Tungsten 101 

Molybdenum, 48 

Vanadium, 68 

Chromium ... 28 

Uranium,.. 60 

Manganese, 28 

Arsenic, 75 

Antimony, 129 

Tellurium, 64 

Bismuth, 213 

Zinc, 32 

Cadmium, 56 

Tin, 59 

Lead, 104 

Iron, 28 

Cobalt 30 

Nickel, 28 

Copper, 32 

Mercury, 100 

Silver, 108 

Gold 200 


Platinum, 99 

Pal ladium, 54 

Rhodiu m, 52 

Iridium, 99 

Osmium, 100 

Ruthenium, 

AUGEE.  An  instrument  for  boring 
the  soil  for  the  purpose  of  ascertaining 
the  nature  of  the  subsoil,  the  mineral, 
and  in  agriculture  more  especially,  the 
existence  of  water.  There  are  various 
kinds  of  augers,  according  to  the  pur- 

Eoses  to  which  they  are  to  be  applied ; 
ut  they  all  consist  of  three  parts,  viz. 
the  bit,  mouth,  or  cutting  piece,  the  han- 
dle, and  the  connecting  rods.  The  handle 
is  for  the  purpose  of  working  the  instru- 
ment by  tne  means  of  two  c-r  more  men, 
the  rods  for  connecting  the  handle  with 
the  bit  or  cutting  piece,  and  the  bit  for 
penetrating  the  soil.  "When  it  is  neces- 
sary to  pass  through  stony  soil  or  rocks, 
a  chisel  is  substituted  for  the  bit :  and 
after  the  rock  is  broken  in  small  pieces, 
the  chisel  is  removed,  and  replaced  by 
the  common  auger,  by  which  the  loose 
matters  are  drawn  up. 

AUEUM  MUSIVUM.  Mosaic  gold. 
An  obsolete  name  for  the  bisulphuret  of 
tin. 

AUTOMATON.  A^name  applied  to 
pieces  of  mechanism  so  constructed  as  to 
imitate  the  actions  of  living  animals.  The 
term  Android  is  sometimes  applied  to 
such  machines  as  resemble  the  figures 
and  imitate  the  actions  of  mankind. 

The  extent  to  which  these  useless  but 
ingenious  contrivances  has  been  some- 
times carried  is  very  surprising.  Archy- 
tas  of  Tarentum,  about  400  years  before 
our  era,  is  said  to  have  made  a  wooden 
pigeon  that  could  fly.  Friar  Bacon's 
speaking  head  is  a  well-known  tradition. 
Albertus  Magnus  constructed  an  automa- 
ton to  open  his  door  when  any  one 
knocked ;  the  celebrated  Kegiomontanus, 
a  wooden  eagle  that  flew  forth  from  the 
city,  saluted  the  emperor,  and  returned : 
and  likewise  an  iron  fly  which  flew  out  of 
his  hand,  and  returned  after  flying  about 
the  room.  These  instances  may  perhaps 
have  been  exaggerated  in  the  description ; 
but  there  are  some  of  recent  date,  and 
not  less  remarkable,  respecting  which  the 
testimony  is  clear  and  strong.  The  fol- 
lowing are  a  few  of  the  best  authenti- 
cated: The  flute-player  of  Vaueanson, 
described  by  D'Alembert  in  the  Encyclo- 
pedie  MetJiodiqve,  was  exhibited  in  Paris 
in  1738.  It  played  on  the  flute  exactly  in 
the  same  manner  as  a  living  performer, 
and  commanded  three  octaves,  the  fullest 


bal] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


25 


scale  of  the  instrument.  Its  height  was 
nearly  six  feet.  In  Mutton's  Mathemati- 
cal liecreations,  a  description  is  given  of 
an  automaton  group,  constructed  by  M. 
Camus  for  the  amusement  of  Louis  XIV., 
consisting  of  a  coach  and  horses,  with 
coachman  and  page,  and  lady  inside,  &c, 
by  which  the  action  of  driving  up,  alight- 
ing, presenting  a  petition  to  the  King,  and 
setting  off  again,  was  mimicked  with 
wonderful  accuracy.  In  1741,  Vaucanson 
produced  a  flageolet-player,  which  played 
the  flageolet  with  the  left  hand,  wnile  it 
beat  a  tamborine  with  the  right.  He 
also  produced  a  duck  which  dabbled  in 
the  water,  swam,  and  drank,  and  quacked 
like  a  real  duck;  raised  and  moved  its 
wings,  dressed  its  feathers  with  its  bill, 
took  barley  from  the  hand  and  swallowed 
it,  and  even  digested  its  food  by  means 
of  materials  for  its  solution  placed  in  the 
stomach. 

Automaton  flute-players  have  likewise 
been  exhibited  in  England  of  the  size  of 
real  life,  which  performed  ten  or  twelve 
duets.  Maelzel,  the  inventor  of  the  me- 
tronome, exhibited  an  automaton  trumpe- 
ter at  Vienna,  of  which  a  description  is 
given  in  the  Journal  des  Modes  lor  1809. 
It  was  a  martial  figure,  in  the  uniform  of 
a  trumpeter  of  an  Austrian  dragoon  regi- 
ment, which  played  not  only  the  Austrian 
and  French  cavalry  marches,  and  all  the 
signals  of  those  armies,  but  also  a  march 
and  an  allegro,  by  Weigl,  accompanied 
by  the  whole  orchestra,  &c. 

Automata  have  also  been  constructed 
which  wrote,  drew  likenesses,  played  on 
the  pianoforte,  &c. 

Professors  Willis  and  Wheatstone  have 
improved  very  much  a  speaking  automa- 
ton ;  and  one  made  by  a  German  was  ex- 
hibited a  few  years  ago  in  London. 

AVANTURINE— Artificial.  MM. 
Fremy  and  Clemandot  have  lately  redis- 
covered the  mode  of  making  this  beauti- 
ful article,  which  has  hitherto  remained  a 
secret  with  the  glass-blowers  of  Venice. 
Having  unsuccessfully  tried  the  action  of 
different  metals  on  glass,  colored  by  oxide 
of  copper,  they  examined  the  reduction 
which  oxides  of  the  minimum  oxydation 
exercised  on  the  protoxide  of  copper,  and 
chiefly  that  of  the  protoxide  of  iron  of 
the  forges.  Under  heat  this  oxide  readily 
reduced  the  protoxide  of  copper  to  me- 
tallic copper,  and  produced  a  metallic 
oxide  soluble  in  glass,  and  giving  it  a 
slightly  yellow  tint.  Heating  300  parts  uf 
pounded  glass,  40  parts  of  protoxide  of 
copper,  and  80  parts  of  oxide  of  iron, 
they  obtained  a  glass  containing  abun- 
2 


dant  crystals  of  metallic  copper.  The 
appearance  of  this  avanturine  is  some- 
what more  opaque  than  the  Venetian  ar- 
ticles ;  but  it  is  no  doubt  produced  in  a 
similar  way.  The  Venetian  avanturine 
fetches  a  very  high  price. 

AXE-STONE.  A  silico-magnesian 
mineral,  sometimes  shaped  by  the  In- 
dians into  cutting  instruments.  A  variety 
of  nephrite. 

AXINITE.  A  mineral  found  in  axe- 
shaped  crystals.  An  alumino  silicate  of 
lime  and  iron. 

AXIS.  In  architecture,  a  real  or  ima- 
ginary straight  line  passing  through  any 
body  on  which  it  may  revolve.  The  axis 
of  a  column,  for  instance,  is  a  straight 
line  drawn  down  through  its  centre  ;  the 
axis  of  the  Ionic  volute  is  a  line  drawn 
through  the  two  eyes,  front  and  rear. 

In  mechanics,  it  signifies  in  general  the 
straight  line,  real  or  imaginary,  about 
which  a  body  turns.  In  this  sense  it  is 
called  the  axis  of  rotation,  of  oscillation, 
&c,  according  to  the  motion  of  the  body. 
In  geometry,  the  axis  of  a  figure  is  a 
straight  line  about  which  the  parts  of  the 
figure  are  symmetrically  disposed.  Thus 
the  axis  of  a  cone  is  the  line  drawn  from 
the  vertex  to  the  centre  of  the  base ;  and 
the  axis  of  a  cylinder,  the  line  drawn 
through  the  centre  of  its  two  ends.  In 
the  ellipse  and  hyperbola,  the  transverse 
axis  is  the  straight  line  drawn  through 
the  two  foci ;  and  the  conjugate  axis,  that 
drawn  through  the  centre,  perpendicular 
to  the  transverse.  In  general,  by  the 
axis  of  a  curve  line  is  meant  that  diame- 
ter which  has  its  ordinates  at  right  angles 
to  it.  We  also  speak  of  the  axis  of  the 
co-ordinates  of  a  curve,  meaning  the  line 
on  which  the  abscissa  are  taken. 

AXLE.     (See  Wheel  Carriages.) 

AXUNGE.    Hogs  lard. 

AZUEE.  A  fine  blue  pigment :  being 
a  glass  colored  with  oxide  of  cobalt,  and 
ground  to  a  very  fine  powder.  (See 
Smalts.) 

BAGASSE.  The  refuse  of  the  sugar 
cane  as  delivered  from  the  mill. 

BAKING.  The  process  of  drying  and 
consolidating  a  substance  by  the  aid  of 
heat. 

BALANCE.  A  machine  for  weighing 
substances.  The  process  of  weighing: 
may  be  performed  in  various  ways,  and 
accordingly  there  are  several  kinds  of 
balances  ;  as  the  common  balance  or 
scales,  the  bent  lever  balance,  the  spring 
balance,  the  steel-yard,  the  hydrostatic 
balance,  &c.  The  term  is  also  applied  to 
any  apparatus  employed  for  comparing 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


the  intensities  of  very  small  forces;  as 
the  electric  balance,  the  balance  of  tor- 
sion, &c.  We  shall  here  confine  our  re- 
marks to  the  philosophical  balance,  the 
instrument  used  when  great  accuracy  is 
necessary  ;  for  instance  in  assaying,  and 
in  the  more  delicate  investigations  of 
phyBics  and  chemistry. 

Neglecting  the  mere  circumstance  of 
construction,  and  the  particular  methods 
of  suspension,  the  balance  may  be  repre- 
sented thus : 


A  and  B  are  the  points  from  which  the 
scales  are  suspended  at  the  extremities 
of  the  beam,  C  the  point  of  support,  G 
the  centre  of  gravity  of  the  beam,  D  the 
point  in  which  the  straight  line  C  G  in- 
tersects the  straight  line  Joining  A  and  B. 

The  properties  required  in  a  good  bal- 
ance are  sensibility  and  stability.  The 
balance  must  be  sensible ;  that  is  to  say, 
when  it  is  properly  poised  a  very  small 
addition  of  weight'to  either  scale  should 
disturb  the  equilibrium,  and  cause  the 
beam  to  turn ;  and  it  must  be  stable,  that 
is  to  say,  when  the  equilibrium  has  been 
disturbed  it  should  quickly  return,  and 
oscillate  about  the  position  of  rest.  These 
two  properties  are  in  some  degree  op- 
posed to  each  other ;  in  order  to  attain 
them  both,  as  far  as  possible,  it  is  neces- 
sary to  attend  to  certain  mechanical  prin- 
ciples, as  well  as  to  the  physical  circum- 
stances of  construction.    Let  us  suppose 

W  =  the  weight  of  the  beam. 

L  =  the  load,  i.  e.  the  weight  of  the 
scales  and  whatever  is  in  them  when 
the  beam  is  poised. 

P  =  the  preponderating  weight,  or  that 
which  causes  the  beam  to  turn. 

Suppose  now  the  beam  to  be  poised, 
or  that  the  scales  being  loaded  the  posi- 
tion of  the  line  A  B  is  perfectly  hori- 
zontal. The  sensibility  wUl  evidently  be 
measured  by  the  angular  space  through 
which  the  beam  turns  when  a  small 
weight  P  is  added  to  either  scale;  but 
the  force  which  acts  in  turning  the  beam 
is  proportional  to  P  X  B  B,  that  is,  pro- 
portional to  the  weight  multiplied  into 
the  length  of  the  lever  at  the  extremity 
of  wh>h  it  acts ;  therefore  for  a  given 
weight  P,  the  sensibility  of  the  balance, 
all  other  circumstances  being  equal,  is 
proportional  to  the  length  of  the  beam. 
Let  us  next  consider  the  force  which 


tends  to  restore  the  beam  when  the  equi- 
librium is  disturbed.    This  is  made  up 
of  two  parts  ;  the  first  of  which  is  pro- 
portional to  W  X  C  G,  that  is  to  say, 
proportional  to  the  weight  of  the  beam 
(which  may  be  regarded  as  concentrated 
at  the  centre  of  gravity)  multiplied  into 
the  length  of  the  lever  on  which  it  acts  ; 
and  the  second  proportional  to  L  X  C  D, 
that  is,  to  the  load  also  multiplied  into 
its  length  of  lever.    The  whole  restoring 
force  is  therefore  proportional  to  W  X 
CG  +  LXCD.    Now  this  force  is  pre- 
cisely   that  which    the    preponderating 
weight  P  has  to  overcome  in  turning  the 
scale ;    consequently   any    circumstance 
which  tends  to  increase  it,  increases  the 
stability  and  diminishes  the  sensibility  of 
the  balance  ;  and  any  thing  which  tends 
to  diminish  it,  diminishes  the  stability 
and  increases  the  sensibility.    By  bend- 
ing the  arms  of  the  balance,  or  altering 
the  points  of  suspension  of  the  scales, 
the  points  G  and  I)  may  acquire  different 
positions  relatively  to  C.    Supposing  G 
to  be  above  C  in  the  vertical  line  joining 
those  points ;  the  term  W  X  C  G  would 
become  negative,  and  the  restoring  force 
proportional  to  L  X  C  D  —  W  X  C  G.  In 
this  case,  if  the  load  L,  or  the  distance 
C  D,  were  diminished  till  L  X  C  D  be- 
came less  than  "W  X  C  G,  the  balance 
would  be  useless ;  because  if  moved  ever 
so  little  from  the  position  of  rest,  it  would 
have  no  tendency  whatever  to  return. 
The  best  construction  is  to  make  CD  = 
I  O,  that  is,  to  place  the  three  points  of 
!  action  A,  C,  B,  in  the  same  straight  line, 
i  and  to  construct  the  beam  so  that  G,  the 
j  centre  of  gravity,  shall  fall  a  little  below 
I  the  line  A  B.    The  sensibility  is  then  in- 
■  dependent  of  the  load,  and  is  simply  in 
i  the  inverse  portion  of  W  X  C  G  ;  so  that 
i  by  diminishing  the  weight  of  the  beam. 
i  or  the  distance  C  G,  it  may  be  increased 
j  to  any  required  degree.    It  is  supposed 
that  the  two  arms  are  precisely  of  the 
I  same  length,  or  that  C  is  placed  exactly 
!  in  the  middle  between  A  and  B,  and 
I  also  that  they  are  perfectly  inflexible. 

The  conditions  now  determined  from 
|  theory  must  be  the  guide  of  the  artist  in 
the  construction  of  a  good  balance.  It  is 
of  importance  that  the  beam  be  as  light 
!  as  possible,  consistent  with  inflexibility ; 
i  for  not  only  the  inertia,  but  also  the  fric- 
j  tion,  is  increased  in  proportion  to  the 
I  weight,  and  the  sensibility  consequently 
|  diminished.  In  order  to  give  lightness 
1  and  strength  at  the  same  time,  the  beam 
!  should  be  formed  of  two  hollow  cones  of 
|  brass,  joined  together  at  the  broad  ends. 


bal] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


27 


A  cylinder  of  steel,  passing  through  the 
middle  of  the  beam  at  right  angles,  forms 
the  axis  •  and  its  extremities,  ground  into 
sharp  edges  on  the  lower  side,  serve  as 
the  points  of  support.  The  two  edges 
must  be  accurately  in  the  same  straight 
line,  and  turn  on  smooth  planes  of  agate 
or  polished  steel  carefully  levelled.  The 
scales  should  likewise  be  suspended  from 
the  extremities  of  the  beam  on  knife 
edges,  crossing  each  other  at  right  an- 
gles: those  in  the  beam  being  sharp  up- 
wards, and  those  to  which  the  scales  are 
attached  sharp  downwards.  A  needle, 
or  tongue,  is  usually  attached  to  the 
beam,  pointing  directly  upwards  or  down- 
wards when  the  beam  is  horizontal,  for 
the  purpose  of  indicating  the  deviations 
of  the  beam  from  the  horizontal  position 
on  a  graduated  scale.  It  is  better,  how- 
ever, to  bring  the  arms  to  terminate  in 
sharp  points,  and  to  place  a  scale  behind 
each ;  in  this  way  the  slightest  flexure 
of  the  beam  will  be  rendered  evident,  if 
the  zeros  of  the  scales  are  placed  exactly 
in  the  same  level.  The  scale  is  indis- 
pensably necessary,  because  the  balance, 
if  very  sensible,  would  require  a  long 
time  to  come  to  rest ;  but  it  is  known  to 
be  poised,  when  the  excursions  of  the 
needle  on  both  sides  of  the  zero  of  the 
scale  are  equal.  In  order  to  preserve  the 
knife  edges,  the  beam,  when  not  in  use, 
is  supported  on  rests.  Props  should  also 
be  placed  under  the  scales  while  loading 
or  unloading  the  balance.  The  whole 
apparatus  must  be  placed  under  a  glass 
case,  to  protect  it  from  the  disturbing  in- 
fluence of  currents  of  air. 

The  sensibility  of  a  balance  constructed 
with  due  care,  according  to  the  princi- 
ples now  explained,  may  be  carried  to  an 
almost  inconceivable  extent.  There  is 
one  in  the  possession  of  the  Royal  So- 
ciety, made  by  Kamsden,  which  weighs 
ten  pounds,  and  is  said  to  turn  with  the 
ten  millionth  part  of  that  load,  or  the 
thousandth  part  of  a  grain.  Neverthe- 
less, whatever  skill  mav  be  employed  in 
the  construction,  it  is  plain  that  the  con- 
ditions necessary  to  mathematical  accu- 
racy can  never  be  entirely  fulfilled.  It  is 
impossible  to  make  the  two  arms  of  the 
beam  exactly  similar,  or  exactly  equal  in 
length.  Absolute  precision  is  unattain- 
able in  practice.  This  difficulty,  how- 
ever, may  be  overcome  by  the  following 
simple  method,  imagined  by  Borda,  by 
which  accurate  results  are  obtained  in- 
dependently of  extreme  precision  in  the 
construction  of  the  balance:  it  is  only 
necessary  that  it  be  very  sensible.    Let 


P,  the  substance  to  be  weighed,  be  placed 
in  the  6cale  A  ;  instead  of  placing  known 
weights  in  the  scale  B,  put  into  it  some 
other  substance,  for  instance  bits  of  iron, 
chips  of  wire,  or  sand,  added  in  minute 
quantities  till  the  substance  P  is  exactly 
counterpoised,  or  the  beam  becomes  ex- 
actly horizontal.  This  being  done,  let 
the  substance  P  be  gently  removed  out 
of  the  scale  A,  and  let  known  weights, 
as  grains,  be  put  into  it  till  the  substance 
in  the  scale  B  is  again  exactly  counter- 
poised. It  is  now  of  no  consequence 
whether  the  balance  was  accurate  or  not, 
or  whether  the  body  P  was  exactly  equal 
in  weight  to  the  substance  against  which 
it  was  weighed  in  B.  The  weight  of  P 
must  be  precisely  equal  to  that  of  the 
grain  weights ;  because,  under  exactly 
the  same  circumstances,  they  both  form- 
ed a  counterpoise  to  the  substance  placed 
inB. 

Odnese  Balance.  This  is  formed  of  a 
slender  tapering  rod  of  wood  or  ivory, 
about  a  foot  in  length.  A  silk  thread 
passed  through  a  hole  perforated  nearer 
one  of  its  extremities  than  the  other, 
serves  as  the  point  of  suspension.  The 
balance  has  thus  two  unequal  arms. 
From  the  extremity  of  the  shorter  a 
small  scale  is  suspended  to  hold  the  sub- 
stance to  be  weighed.  A  sliding  weight 
passes  along  the  other  arm,  on  which 
divisions  are  marked  ;  and  when  the 
counterpoise  is  made,  the  distance  of  the 
standard  weight  from  the  fulcrum  indi- 
cates the  weight  of  the  substance.  In 
order  to  procure  a  greater  range,  the  rod 
has  generally  four  holes  or  points  of  sup- 
port, at  different  distances  from  the  ex- 
tremity, and  a  corresponding  set  of  divi- 
sions is  marked  on  each  of  its  four  sides. 
The  principle  of  this  machine  is  exactly 
the  same  as  that  of  the  common  steel- 
yard. 

The  Danish  Balance,  much  used  in  the 
north  of  Europe  for  weighing  coarse  com- 
modities, is  usually  formed  of  an  iron 
bar  or  a  batten  of  hard  wood,  having  a 
lump  of  lead  at  one  of  its  extremities. 
The  goods  are  fixed  on  a  hook  in  the 
other  end ;  and  the  whole  is  suspended 
through  a  loop  of  cord,  which  is  passed 
backwards  and  forwards  under  the  rod 
till  equilibrium  is  obtained.  The  weight 
of  the  goods  is  then  to  the  weight  of  the 
lead  reciprocally  as  their  respective  dis- 
tances from  the  loop. 

Roman  Balance  or  Steelyard.  {See 
Steelyard.) 

BALCONY.  In  architecture  a  projec- 
tion from  the  external  wall  of  a  nouse, 


28 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[bal 


borne  by  columns  or  consoles ;  usually 
placed  before  the  windows  or  openings. 

BALLAST.  Is  a  mass  of  weighty  ma- 
terial placed  in  the  bottom  of  a  ship  or 
vessel  to  give  her  stiffness  ;  that  is,  to  in- 
crease her  tendency  to  return  to  the  up- 
right position  when  inclined  or  heeled 
over  by  the  force  of  the  wind  or  other 
cause.  Ballast  consists  of  shingle  (the 
coarse  gravel  of  the  sea-beach),  stones, 
&c.  This  tends  to  give  excess  of  stabi- 
lity, which  renders  the  vessel  uneasy 
from  the  suddenness  of  the  motion :  this 
defect  is  remedied  by  winging  up  the 
ballast,  whereby  its  centre  of  gravity  is 
raised.  For  the  like  reason  in  stowing 
the  ballast  it  is  tapered  to  a  point  at  the 
fore  and  after  extremities.  Iron  ballast, 
from  the  greater  cleanliness,  is  more 
healthy  for  the  crew  than  that  of  other 
materials.  When  a  ship  has  no  other 
loading,  she  is  said  to  be  in  ballast. 

The  quantity  of  ballast  and  the  mode 
of  its  stowage  differ  greatly  in  different 
vessels  ;  and  the  connection  between  the 
motions  of  a  ship  and  her  stowage  has 
not  yet  been  analyzed  sufficiently  to  lead 
to  the  discovery  of  direct  rules  on  these 
important  points. 

BALL-COCK.  A  hollow  sphere  or 
ball  of  metal  attached  to  the  end  of  a 
lever,  which  turns  the  stop-cock  of  a 
cistern  pipe,  and  regulates  the  supply  of 
water.  As  the  surface  of  the  water  rises 
in  the  cistern,  the  ball  is  raised  by  its 
buoyancy  ;  and  as  the  water  descends,  it 
falls  by  its  own  weight.  The  cock  is  thus 
closed  when  the  water  rises  to  a  certain 
height,  and  the  supply  stopped;  but 
when  a  part  of  the  water  is  drawn  off 
from  the  cistern,  the  cock  is  again  open- 
ed, and  the  water  admitted  through  the 

BALLISTIC  PENDULUM.  An  in- 
strument, invented  by  Benjamin  Eobins, 
for  measuring  the  force  or  velocity  of 
cannon  and  musket  balls.  To  one  ex- 
tremity of  an  iron  bar  is  fixed  a  heavy 
cubical  block  of  wood,  lined  at  the  back 
with  iron.  A  transverse  bar  of  iron  at 
the  other  extremity  of  the  first  bar  serves 
as  an  axis  of  suspension,  in  which  the 
pendulum  swings  freely  backwards  and 
forwards.  The  instrument  being  thus 
fitted,  if  the  weight  of  the  pendulum  be 
known,  and  likewise  the  respective  dis- 
tances of  its  centres  of  gravity  and  oscilla- 
tion from  the  axis  of  suspension,  it  is 
easy  to  determine  the  quantity  of  motion 
that  will  be  communicated  to  the  pendu- 
lum by  the  percussion  of  a  body  of  a 
given  weight  moving  with  a  given  velo- 


city and  striking  it  at  a  given  point.  Con- 
versely, if  the  pendulum,  when  at  rest,  is 
struck  by  a  body  of  a  known  weight, 
and  the  vibration  which  the  pendulum 
makes  after  the  blow  is  known,  the  velo- 
city of  the  striking  body  may  thence  be 
determined.  In  order  to  measure  the 
extent  of  the  vibration,  a  riband  is  at- 
tached to  the  lower  end  of  the  pendu- 
lum, passing  loosely  through  an  orifice 
in  a  horizontal  bar  in  the  frame-work : 
when  the  pendulum  is  raised  it  draws 
the  riband  along  with  it,  and  the  quan- 
tity which  thus  passes  through  the  ori- 
fice measures  the  chord  of  the  are  of 
vibration. 

BALLOON.  (Fr.  ballon,  a  little  ball.) 
The  name  of  a  machine,  which,  consist- 
ing of  an  envelope  containing  a  gas  speci- 
fically lighter  than  common  air,  rises  into 
the  atmosphere  with  a  greater  or  less  de- 
gree of  ascensional  force.  A  car,  sup- 
ported by  a  net-work  which  extends  over 
the  balloon,  supports  the  aeronaut :  and  a 
valve,  usually  placed  at  the  top,  to  which 
a  string  is  attached  reaching  to  the  car, 
gives  him  the  power  of  allowing  the  gas 
to  escape,  and  of  descending  at  pleasure. 

During  the  dark  ages,  and  for  some 
time  after  the  revival  of  science,  numer- 
ous projects  were  entertained  for  navigat- 
ing the  air ;  but  it  is  only  in  very  recent 
times,  since  1783,  that  any  of  them  have 
been  realized.  The  first  idea  was  to  em- 
ploy some  mechanical  contrivance  resem- 
bling the  wings  of  birds  ;  but  Borelli  de- 
monstrated that  all  attempts  on  the  part 
of  man  to  fly  must  necessarily  fail,  from 
the  utter  disproportion  of  his  muscular 
power  to  the  force  that  would  be  neces- 
sary to  give  impulsion  to  wings  of  such 
enormous  magnitude  as  would  be  required 
to  sustain  his  weight  in  the  air. 

The  principle  by  which  a  balloon  rises 
in  the  atmosphere  is  exactly  the  same  as 
that  which  causes  the  ascent  of  a  cork 
from  the  bottom  of  a  vessel  filled  with 
water.  The  weight  of  the  volume  of  air 
which  it  displaces  must  exceed  the  weight 
of  the  balloon  and  all  that  it  carries  with 
it.  That  bodies  must  rise  and  remain 
suspended  in  a  fluid  denser  than  them- 
selves was  proved  by  Archimedes ;  but 
the  weight  of  the  air  is  a  modern  discov- 
ery •  and  it  was  only  in  the  latter  half  of 
the  last  century  that  chemistry  detected 
the  nature  and  differences  of  specific  gra- 
vities of  aeriform  fluids.  Mr.  Cavendish, 
in  1766,  by  some  ingenious  experiments, 
recorded  in  the  I'hilosophical  Transactions, 
vol.  lvi.,  found  hydrogen  gas  to  be  from 
about  seven  to  eleven  times  lighter  than 


bal] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


29 


common  air,  according  to  the  mode  of  its 
preparation.  In  its  pure  state  it  is  found 
to  be  nearly  sixteen  times  lighter  than 
common  air.  This  substance,  therefore, 
if  prevented  from  diffusing  itself,  and  al- 
lowed to  obey  the  force  "by  which  it  is 
impelled  upwards,  will  continue  to  mount 
till  it  arrives  at  a  stratum  of  the  atmos- 
phere sixteen  times  more  attenuated  than 
at  the  surface  of  the  earth.  Accordingly, 
no  sooner  had  Cavendish  announced  his 
discovery,  than  it  occurred  to  Dr.  Black 
that  a  very  thin  bag  rilled  with  hydrogen 
gas  would  mount  to"  the  ceiling  of  a  room. 
Through  some  imperfection,  the  experi- 
ment when  he  attempted  to  execute  it 
failed :  and  it  was  several  years  later  be- 
fore an  envelope  was  thought  of  suffici- 
ently light,  and  at  the  same  time  imper- 
meable to  the  gas.  Cavallo  made  a  series 
of  experiments  on  this  subject  in  1782, 
but  did  not  succeed  in  raising  any  thing 
heavier  than  a  soap-bubble.  The  expense 
attending  the  preparation  of  the  gas  Pro- 
bably prevented  the  experiment  from 
being  made  on  a  great  scale. 
Knowing  the  specific  gravities  of  atmos- 

f)heric  air,  of  the  gas  with  which  the  bal- 
oon  is  to  be  filled,  and  the  weight  of  the 
envelope  in  which  it  is  confined,  it  is  not 
difficult  to  compute  the  size  the  balloon 
must  have  in  order    to  rise   from  the 

ground,  or  carry  a  given  weight  to  a  given 
eight  in  the  atmosphere.  A  globe  of 
air,  one  foot  in  diameter,  at  the  level  of 
the  sea  and  under  the  ordinary  pressure, 
weighs  about  l-25th  of  a  pound  avoirdu- 
pois. An  equal  globe  of  hydrogen  gas, 
obtained  in  the  usual  way  by  dissolving 
iron  filings  in  dilute  sulphuric  acid,  may 
be  assumed  (making  every  allowance  for 
imperfect  preparation)  to  be  about  six 
times  lighter  than  atmospheric  air  ;  con- 
sequently 5-6ths  of  its  whole  buoyant 
force  will  act  in  impelling  it  upwards : 
that  is  to  say,  the  force  with  which  a 
sphere  of  such  gas,  one  foot  in  diameter, 
will  tend  to  rise  in  the  atmosphere,  will 
be  J-XfT—^V  °f  a  pound  avoirdupois. 
The  ascensional  forces  of  different  spheres 
will  be  proportional  to  their  magnitudes, 
that  is  to  the  cubes  of  their  diameters : 
therefore  a  sphere  12  feet  in  diameter 
would  rise  with  a  force  of  57  pounds,  and 
one  of  24  feet  in  diameter  with  a  force  of 
8X57=456  pounds.  But  these  determina- 
ations  must  be  diminished  by  the  weight 
of  the  envelope.  The  best  material  for 
the  purpose  at  present  known  is  thin 
silk  varnished  with  elastic  gum,  or  Indian 
rubber.  The  quantity  of  this  material 
required  to  cover  a  globe  one  foot  in  di- 


ameter, weighs  about  l-20th  if  a  pound. 
Now  for  a  globe  of  a  greater  size,  the 
quantity  required  will  increase  with  the 
square  of  the  diameter ;  hence  the  cover- 
ing of  a  balloon  12  feet  in  diameter  must 
weigh  about  7  pounds,  and  of  one  24  feet 
in  diameter  28  pounds.  It  follows,  there- 
fore, that  a  balloon  of  12  feet  diameter 
will  only  raise  from  the  ground  a  weight 
of  50  pounds,  and  one  of  24  feet  428 
pounds.  Computing  in  the  same  man- 
ner, it  is  found  that  a  balloon  60  feet  in 
diameter  would  raise  a  weight  equal  to 
about  6,950  pounds ;  and  that  one  of  a 
foot  and  a  half  would  barely  float,  the 
weight  of  the  bag  being  just  equal  to  that 
of  the  imprisoned  gas. 

The  height  to  which  a  balloon  will  rise 
is  determined  from  the  law  according  to 
which  the  density  of  the  atmospheric 
strata  diminishes  as  the  distance  from  the 
earth  is  increased.  The  buoyant  force 
diminishes  with  the  density ;  and  when 
it  is  reduced  to  a  quantity  only  equal  to 
the  weight  of  the  balloon  and  its  appen- 
dages, no  further  ascension  can  take 
place.  Another  circumstance  also  con- 
fines the  possible  elevation  within  moder- 
ate limits.  As  the  pressure  of  the  exter- 
nal air  is  diminished,  the  expansive  force 
of  the  confined  gas  becomes  greater,  and 
would  ultimately  overcome  the  resistance 
of  any  material  of  which  a  balloon  can  be 
made.  A  balloon  quite  filled  at  the  sur- 
face of  the  earth  would  inevitably  be  torn 
to  shreds  at  the  height  of  a  few  miles  in 
the  atmosphere,  unless  a  portion  of  the 
gas  were  allowed  to  escape.  For  this  pur- 
pose the  balloon  is  iurnished  with  a 
safety  valve,  which  can  be  opened  and 
shut  at  pleasure  ;  but  to  prevent  unneces- 
sary waste  of  gas,  it  ought  to  be  made  of 
such  a  size  that  it  requires  only  to  be 
partly  filled.  A  balloon  half  filled  at  the 
surface  of  the  earth  would  become  fully 
distended  at  the  height  of  3£  miles. 

We  have  hitherto  spoken  only  of  bal- 
loons filled  with  hydrogen  gas  ;  but  it  is 
evident  that  any  other  substance  specific- 
ally lighter  than  air  would  answer  the 
purpose;  in  fact,  the  first  balloons  by 
which  any  one  was  raised  into  the  atmos- 
phere were  not  filled  with  hydrogen,  but 
simply  with  rarefied  air,  the  rarefaction 
being  produced  by  kindling  a  Are  under 
them;  and  as  they  thus  became  filled 
with  smoke,  they  were  called  smoke-bal- 
loons. The  ascensional  force,  however, 
which  can  be  gained  in  this  way  is  not 
great ;  besides  the  aeronaut  must  carry  a 
portion  of  fuel  with  him  for  the  purpose 
of  maintaining  the  fire,  which  adds  scnsi- 


30 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[bal 


bly  to  the  weight  to  he  raised.  The  keep- 
ing up  of  the  fire  is  also  attended  with 
inconvenience,  and  even  danger. 

Two  brothers,  Stephen  and  Joseph 
Montgolfier,  proprietors  of  a  paper  manu- 
factory at  Annonay  in  France,  have  the 
honour  of  first  preparing  and  sending  up 
a  balloon  into  the  air.  After  one  or  two 
previous  trials,  they  announced  a  public 
ascent  on  the  5th  of  June,  1783.  The 
balloon  was  prepared  of  linen  cloth ;  a 
fire  was  kindled  under  it,  and  fed  with 
bundles  of  chopped  straw.  This  sub- 
stance was  used  with  a  view  to  produce 
a  large  quantity  of  smoke.  It  would 
seem  that  they  attributed  the  elevation  of 
the  balloon  to  the  ascending  power  of  the 
smoke,  instead  of  its  true  cause,  the  rare- 
faction of  the  heated  air.  In  the  space 
of  five  minutes  it  was  completely  dis- 
tended ;  and  on  being  let  slip,  ascended 
rapidly.  It  reached  an  elevation  of  about 
a  mile,  remained  suspended  ten  minutes, 
and  fell  at  the  distance  of  a  mile  and  a 
half  from  the  place  of  its  ascension. 
When  the  news  of  this  experiment  was 
carried  to  Paris,  the  surprise  was  general, 
and  the  virtuosi  began  immediately  to 
consider  how  it  could  be  repeated.  It 
was  determined  to  apply  hydrogen  gas  on 
this  occasion ;  and  Charles,  a  celebrated 
lecturer  on  natural  philosophy,  undertook 
the  superintendence  of  the  process.  On 
the  26th  of  August,  1783,  the  preparations 
were  complete,  and  the  balloon  was  trans- 

Sorted  with  much  ceremony  to  the  Champ- 
e-Mars.  On  the  following  day,  at  five 
o'clock  in  the  afternoon,  the  report  of  a 
cannon  announced  to  the  assembled  mul- 
titude that  every  thing  was  ready.  "  The 
globe,  liberated  from  its  stays/ shot  up- 
wards, to  the  great  surprise  "of  the  spec- 
tators, with  such  rapidity  that  in  two 
minutes  it  reached  the  height  of  3000 
feet.  It  traversed  successively  several 
clouds,  by  which  it  was  repeatedly  ob- 
scured. The  violent  rain  which  began  to 
fall  at  the  moment  of  its  ascent  did  not 
retard  its  rapid  progress,  and  the  experi- 
ment was  attended  with  complete  success. 
The  satisfaction  was  so  great  that  even 
elegantly  dressed  ladies  remained  with 
their  eyes  intently  fixed  on  the  balloon, 
regardless  of  the  rain,  which  fell  on  them 
in  torrents."  (Libes.  Dktionnaire  de 
Physique.)  This  balloon  remained  in  the 
atmosphere  only  three  quarters  of  an 
hour ;  it  fell  at  a  distance  of  about  fifteen 
miles,  when  it  was  discovered  that  a  rent 
was  made  in  the  upper  part,  through 
which  the  gas  had  escaped. 
The  first  adventurers  who  had  courage 


to  undertake  an  aerial  ascent  in  a  balloon, 
were  Pilatre  de  Kosier,  a  young  naturalist, 
and  the  Marquis  d'Arlandes.  On  the 
21st  of  November,  1783,  they  took  their 
seats  in  the  basket  of  a  smoke  balloon ; 
and  after  rising  to  am  elevation  of  upwards 
of  3000  feet,  descended  safely  to  the 
earth.  The  next  ascent  was  made  by 
MM.  Charles  and  Kobert  in  a  balloon  filled 
with  hydrogen  gas,  on  the  1st  of  January, 
1784.  After  a  flight  of  a  hour  and  a  half 
they  alighted  on  the  meadow  of  Nesle, 
about  twenty-five  miles  from  Paris,  with- 
out the  slightest  accident.  As  the  bal- 
loon still  retained  a  considerable  buoyant 
force,  M.  Charles  resolved  on  another 
ascent  alone.  It  rose  to  the  height  of 
near  two  miles  in  about  ten  minutes ;  and 
the  aeronaut  had  the  satisfaction  of  see- 
ing the  sun,  which  had  set  when  he  left 
the  earth,  again  rise  above  the  horizon. 
After  remaining  about  thirty-five  minutes 
in  the  air,  he  descended  safely  at  a  dis- 
tance of  about  nine  miles  from  the  spot 
from  which  he  had  risen. 

So  many  aerial  voyages  executed  with 
safety  encouraged  other  attempts  :  and 
no  accident  occurred  till  the  accomplished 
Pilatre  de  Eosier,  with  his  companion 
Eomain,  were  killed  in  an  attempt  to 
cross  the  channel  from  France  to  England. 
On  the  13th  of  June,  1785,  they  ascended 
from  Boulogne.  Under  the  principal  bal- 
loon, which  was  of  hydrogen  gas,  they 
had  suspended,  for  the  purpose  of  in- 
creasing or  diminishing  the  ascensional 
power  at  pleasure,  a  smoke  balloon,  which 
occasioned  the  disastrous  issue.  Scarcely 
a  quarter  of  an  hour  had  elapsed  when 
the  whole  apparatus,  at  the  height  of  3000 
feet,  was  perceived  to  be  on  fire,  and  the 
unfortunate  voyagers  were  precipitated 
to  the  ground.  This  calamitous  occur- 
rence, however,  did  not  damp  the  cour- 
age of  aeronauts.  It  was  obvious  that  it 
had  been  occasioned  by  the  want  of  pro- 
per precautions ;  accordingly  ascents  con- 
tinued to  be  multiplied,  and  have  since 
become  so  common  as  to  be  an  ordinary 
spectacle  in  the  principal  cities  of  Europe. 

When  balloons  first  began  to  be  con- 
structed, it  was  expected  that  they  would 
be  found  applicable  to  many  important 
purposes.  These  expectations  have  been 
disappointed,  chiefly  because  it  has  been 
found  impossible  to  guide  or  control 
their  course.  The  only  power  the  aero- 
naut possesses  over  hisballoon  is  to  regu- 
late its  elevation  within  certain  limits. 
In  one  or  two  instances  they  have  been 
successfully  used  for  military  reconnois- 
sance.    The  victory  which  Jourdan  ol>- 


bar] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


31 


tained  over  the  Austrians  at  Fleurus,  in 
1794,  was  ascribed  to  the  knowledge  ob- 
tained of  the  enemy's  movements  by 
means  of  a  balloon.  A  very  interesting 
ascent  was  made  by  Biot  ancf  Gay  Lussac, 
in  August  1804,  and  by  Gay  Lussac  alone 
in  September  of  the  'same  year,  with  a 
view  to  make  meteorological  observations 
in  the  upper  strata  of  the  atmosphere. 
In  the  first  voyage,  the  two  philosophers, 
at  an  elevation  of  between  9,500  and 
13,000  English  feet,  found  the  oscillations 
of  the  magnetic  needle  to  be  perfonned 
in  the  same  time  as  at  the  surface  of  the 
earth.  At  12,800  feet  the  thermometer, 
which  stood  at  63i°  at  the  observatory, 
had  sunk  to  51°  of  Fahrenheit,  being^ 
only  a  decrease  of  1°  for  every  thousand 
feet.  The  hygroscope  indicated  increased 
dryness  in  proportion  to  the  elevation. 
In  the  second  ascent,  performed  by  Gay 
Lussac  alone,  the  variation  of  the  com- 
pass at  the  height  of  12,680  was  found  to 
remain  unaltered.  At  14,480  feet,  a  key 
held  in  the  magnetic  direction  attracted 
with  one  end  and  repelled  with  the  other 
the  north  pole  of  the  magnetic  needle. 
The  same  was  the  case  at  20,150.  At 
18,000  feet  the  thermometer  fell  to  the 
freezing  point,  and  at  22,912  feet  to  14-9° 
of  Fahr.  Two  flasks,  which  had  been 
previously  emptied  of  air,  were  opened 
and  filled  at  an  elevation  exceeding  21,400 
feet;  and  the  air  brought  down  from  this 
region  was  found,  on  being  analyzed,  to 
contain  exactly  the  same  proportions  of 
the  constituent  elements  as  at  the  surface. 
The  utmost  elevation  which  he  reached 
was  23,040  feet,  or  four  miles  and  a  quar- 
ter above  the  level  of  the  sea,  consider- 
ably higher  than  the  loftiest  peak  of  the 
Andes. 

Excepting  in  these  two  remarkable  as- 
cents of  Gay  Lussac,  nothing  has  been 
gained  to  science  by  the  use  of  balloons. 
The  numerous  other  ascents  undertaken, 
both  before  and  since,  have  as  yet  served 
no  other  purpose  than  to  gratify  idle  curi- 
osity ;  and  from  the  totalfailure  of  every 
scheme  that  has  been  proposed  for  direct- 
ing their  course  through  the  air,  there  is 
little  rvason  to  anticipate  any  great  advan- 
tages from  them  to  society.  Neverthe- 
less, the  comparative  cheapness  and  fa- 
cility with  which  they  can  be  filled  by 
coaf  gas,  now  so  generally  used  for  the 
purposes  of  illumination,  have  been  the 
cause  of  directing  public  attention  to  the 
subject.  Mr.  Green  crossed  the  channel 
from  Vauxhall  to  Nassau,  in  Germany, 
in  1836,  after  a  journey  of  eighteen  hours, 
carrying  two  companions  and  a  ton  of 


ballast.  This  feat  (crossing  the  English 
Channel),  has  been  repeated  since  more 
than  once, — the  last  voyage  being  in  the 
spring  of  1851  from  London,  and  landing 
within  a  few  miles  of  Boulogne. 

BALSAMS.  Exudations  from  and 
juices  of  certain  plants  which  are  liquid, 
or  soft-solid,  and  consist  of  a  substance 
resembling  resin  either  combined  with 
Benzoic  acid  or  an  essential  oil,  or  both. 
The  principal  balsams  are  those  of  Peru, 
Tolu,  Benzoin  storax,  and  liquidambar. 
Those  contain  Benzoic  Acid,  while  Co- 

J)aiva  balsam,  Mecca  balsam,  and  Japan- 
ac  do  not. 

BALUSTRADE.  A  parapet  or  pro- 
tecting fence  formed  with  balusters. 

BANDANA.     (See  Calico  Printing.) 

BARBERRY.     (See  Berberry.) 

BARILLA.  The  name  given  to  the 
impure  carbonate  of  soda  imported  from 
Spain  and  the  Levant.  It  is  the  ash  of 
the  salsola  soda  and  other  plants,  which 
are  grown  on  the  shore  for  the  purpose 
of  supplying  the  ash.  It  seldom  contains 
more  than  20  per  cent,  of  real  alkali,  be- 
sides sulphates  and  chlorides  of  soda, 
lime,  and  alumina,  with  some  sulphur. 
It  was  much  used  in  soap  manufacture  ; 
it  is  now  almost  entirely  superseded  by 
the  carbonate  of  soda  obtained  from 
common  salt. 

BARIUM.  The  metallic  base  of  bary- 
ta. It  is  a  white  metal,  of  the  color  and 
lustre  of  silver,  malleable,  fusing  below 
a  red  heat,  oxidizing  in  the  air,  and  de- 
composing water.  The  oxide  of  barium 
or  baryta  is  abundant  in  nature,  as  car- 
bonate and  sulphate  of  baryta,  forming 
the  vein-stone  in  many  lead  mines.  Pure 
baryta  is  a  white  earth,  resembling  lime 
in  its  affinity  for  water  and  carbonic  acid. 
Nearly  all  the  baryta  compounds  are  poi- 
sonous, except  the  sulphate.  The  best 
antidote  is  a  solution  of  sulphate  of  soda. 
Baryta,  of  all  substances,  has  the  greatest 
affinity  for  sulphuric  acid.  The  sulphate 
of  baryta  is  used  as  a  pigment  "perma- 
nent white,"  and  as  an  adulteration  in 
white  lead  ;  it  is  also  used  in  the  manu- 
facture of  jasper  and  other  earthen  ware. 

BARK.  The  outer  covering  of  the 
trunk  of  the  tree.  It  is  the  depository 
of  many  of  the  secretions  of  the  plant, 
and  generally  contains  a  large  quantity 
of  tannic  and  gallic  acids.  The  most 
important  barks  are  those  of  the  oak  and 
cinchona  trees :  for  which  see  Tanning 
and  Peruvian  Bark. 

BARLEY.  A  valuable  grain  for  malt- 
ing, but  a  poor  one  for  bread :  the  seeds 
of  the  Hordeum  distichon.      It  grows 


32 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[bar 


well  on  light  lands,  and  is  used  in  fattening 
black  cattle,  hogs,  and  poultry.  30  bush- 
els is  a  good  crop  of  63  lb.  each,  and  the 
weight  of  the  straw  is  about  1-Gth  more. 

1000  parts  of  barley  contain,  according 
to  Einhof,  starch,  720 ;  mucilage,  50  ; 
sugar,  56 ;  gluten,  36*6  ;  vegetable  albu- 
men, 12-3  ;  water,  100  ;  phosphate  of 
lime,  2-5  ;  ligneous  matter,  68.  Pot  bar- 
ley is  barley  deprived  of  its  outer  skin  ; 
pearl  barley  lias  also  a  portion  of  the 
grain  removed,  leaving  merely  a  small 
round  kernel.  Both  kinds  are  made  in 
the  same  mill,  but  the  pearl  barley  re- 
ceives more  grinding. 

BARM.  Another  name  for  yeast.  (See 
Beer.) 

BAROMETER.  A  well-known  instru- 
ment for  measuring  the  weight  or  pres- 
sure of  the  atmosphere.  The  invention 
of  the  barometer  was  in  some  degree 
owing  to  an  accident.  Some  workmen 
employed  by  the  Duke  of  Florence  to 
prepare  a  sucking-pump  for  a  deep  well, 
found  to  their  surprise  that  notwith- 
standing the  "utmost  care  in  forming  and 
fitting  the  valves  and  piston,  the  water 
would  not  rise  higher  than  18  palms,  or 
about  32  English  feet.  For  an  explanation 
of  this  unexpected  difficulty  they  applied 
to  the  illustrious  Galileo,  then  passing 
the  evening  of  his  life  at  his  villa  near 
Arcetri ;  but  the  philosopher  was  not  yet 
prepared  with  the  true  answer.  In  that 
age  the  doctrine  of  a  plenum  was  an 
axiom  in  philosophy  ;  and  the  ascent  of 
water  in  the  barrel  of  the  pump  was  uni- 
versally ascribed  to  nature's  horror  of  a 
vacuum.  Galileo,  either  fearing  to  en- 
counter further  persecutions  by  pro- 
pounding opinions  at  variance  with  the 
prejudices  of  the  times,  or  pre-occupied 
by  the  prevailing  metaphorical  modes  of 
expression,  evaded  the  difficulty  by  say- 
ing that  the  power  of  nature  to  overcome 
a  vacuum  was  limited,  and  did  not  ex- 
ceed the  pressure  of  a  column  of  water 
82  feet  in  height.  That  he  was  himself 
little  satisfied  with  this  explanation,  is 
evident  from  the  circumstance  that  pre- 
viously to  his  death,  which  happened 
soon  after,  in  1642,  he  earnestly  recom- 
mended to  his  pupil  Torricelli  to  under- 
take the  investigation  of  the  subject, 
which  the  infirmities  of  advanced  age  no 
longer  permitted  him  to  prosecute.  Tor- 
ricelli, suspecting  the  true  cause  of  the 
suspension  of  the  water,  namclv,  the 
weight  of  the  atmosphere,  happily  con- 
ceived the  idea  of  trying  the  experiment 
with  mercury.  He  perceived  that  if  the 
weight  of  the  atmosphere  forms  a  coun- 


terpoise to  a  column  of  water  of  32  feet, 
it  must  also  counterpoise  a  column  of 
mercury  of  about  28  inches  in  height, 
the  weight  of  mercury  being  about  14 
times  greater  than  that  of  water.  Hav- 
ing accordingly  procured  a  glass  tube  of 
about  3  feet  in  length  and  a  quarter  of 
an  inch  in  diameter,  hermetically  sealed 
at  one  end,  he  filled  it  with  mercury ; 
and  covering  the  open  end  with  the  fin- 
ger, he  immerged  it  in  an  open  vessel 
containing  mercury.  On  bringing  the 
tube  to  the  vertical  position,  and  remov- 
ing the  finger,  the  mercury  instantly 
sank,  leaving  a  vacuum  at  the  top  of  the 
tube,  and,  after  making  several  oscilla- 
tions, stood  in  the  tube  at  the  height  of 
about  28  inches  above  the  surface  of  that 
in  the  vessel.  On  covering  the  mercury  in 
the  vessel  with  a  portion  of  water,  and  rais- 
ing the  tube  till  the  lower  end  came  into 
contact  with  the  water,  the  mercury  all  ran 
out,  and  the  water  rushed  up  to  the  top  of 
the  tube.  This  experiment,  called  after  its 
author  the  Torricellian  experiment,  de- 
monstrated that  the  mercury  was  sustain- 
ed in  the  tube,  and  the  water  in  the 
barrel  of  the  pump,  by  exactly  the  same 
counterpoise,  whatever  the  nature  of  it 
might  be.  Torricelli  died  shortly  after, 
in  the  flower  of  his  age,  without  com- 
pleting his  great  discovery ;  but  the  fame 
of  his  experiment  was  soon  carried  into 
other  countries,  and  the  subject  engaged 
the  attention  of  the  most  eminent  phi- 
losophers; among  others  the  celebrated 
Pascal.  After  a  variety  of  ingenious  ex- 
periments on  the  subject,  all  of  which 
tended  to  establish  the  pressure  of  the 
atmosphere,  it  at  length  occurred  to  Pas- 
cal that  if  the  mercurial  column  was 
really  supported  by  atmospheric  pres- 
sure, it  must  be  affected  by  the  weight 
of  the  superincumbent  mass  of  air,  and 
consequently  be  diminished  at  considera- 
ble elevations.  In  order  to  verify  this 
conjecture,  he  requested  his  brother-in- 
law,  Perier,  to  try  the  experiment  on  the 
Puy  de  Dome,  a  lofty  conical  mountain 
in  the  province  of  Auvergne,  which  rises 
to  the  height  of  500  toises.  At  the  foot 
of  the  mountain  Perier  filled  two  tubes, 
and  observed  the  mercury  in  each  to 
stand  at  precisely  the  same  height,  nearly 
28  English  inches.  Leaving  oiie  of  them 
under  the  care  of  a  person  to  watch  its 
rise  and  fall,  he  carried  the  other  to  the 
top  of  the  mountain ;  and  on  repeating 
the  experiment  there,  the  mercury  stood 
at  the  height  of  only  24*7  English  inches. 
At  two  intermediate  stations  in  his  de- 
scent, the  mercury  was  observed  succes- 


bar] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


33 


sively  to  rise,  and  at  the  foot  of  the  moun- 
tain it  stood  at  exactly  the  same  height 
in  the  tube  as  at  first.  This  experiment 
was  decisive ;  the  result  of  it  was  com- 
municated to  Pascal  at  Paris,  who,  after 
confirming  it  by  similar  observations 
made  successively  on  the  ground,  and  at 
the  top  of  a  glass-house  and  the  belfry  of 
a  church,  proposed  the  barometer  as  an 
instrument  for  measuring  the  height  of 
mountains,  or  the  relative  altitudes  of 
places  above  the  surface  of  the  earth. 

The  barometer  had  been  but  a  short 
time  invented  before  it  was  observed  that 
the  height  of  the  mercurial  column  is 
subject  to  variations  connected  in  some 
way  with  the  changes  of  weather.  But 
the  variations  are  confined  within  a  limit- 
ed range,  scarcely  exceeding  3  inches  in 
all,  and  often,  for  many  days  together, 
do  not  exceed  a  few  hundredths  of  an 
inch.  It  therefore  was  considered  de- 
sirable to  render  these  minute  oscilla- 
tions more  apparent  by  increasing  their 
range ;  and  accordingly,  of  the  numerous 
forms^  which  the  barometer  has  received, 
or  which  have  been  suggested,  the  greater 
part  have  been  proposed  with  a  view  to 
this  purpose.  The  most  remarkable  or 
useful  constructions  are  the  following, 
the  descriptions  of  which  will  be  readily 
understood  with  the  assistance  of  the 
diagrams : — 


Fig.  1,  is  the  Cistern  Barometer,  and  is 
merely  the  inverted  tube  of  Torricelli 
alroady  described.  The  tube  must  be 
about  34  inches  long.  When  placed  in 
the  cistern,  the  mercury  sinks  till  the 
column  between  the  two  surfaces  m  and 
n  just  counterbalances  the  pressure  of  the 
air.  The  space  above  the  mercury,  a  m, 
is  or  ought  to  be  a  perfect  vacuum,  or 
only  filled  with  the  vapor  of  mercury.  In 
this  barometer,  as  the  diameter  of  the 
cistern  is  generally  very  much  greater 
2* 


i  than  that  of  the  tube,  almost  the  whole 
effect  of  the  rise  or  fall  is  perceived  in 
the  variation  of  the  upper  surface  at  m. 
For  supposing  the  section  of  the  cistern 
20  times  greater  than  that  of  the  tube, 
and  that  the  height  of  the  column  m  n 
sutlers  a  diminution  of  one  inch ;  it  is 
evident  that,  as  all  the  mercury  which 
goes  out  of  the  tube  passes  into  the  cis- 
tern, when  it  falls  at  m  it  must  rise  at  n, 
but  less  in  proportion  as  the  section  of 
the  cistern  exceeds  that  of  the  tube.  In 
the  case  supposed,  therefore,  the  altera- 
tion of  the  level  at  m  will  be  20  times 
greater  than  at  n;  that  is  to  say,  there  will 
be  a  fall  of  §T  of  an  inch  at  m,  and  a  rise 
of  2V  of  an  inch  at  n. 

Fig.  2,  is  the  Siplion  Barometer,  which 
was  also  proposed  by  Torricelli,  as  being 
more  convenient  than  the  former.  It  is 
merely  a  tube  hermetically  sealed  at  the 
upper  end,  having  the  lower  or  open  end 
bent  upwards  in  the  form  of  a  siphon. 
The  variations  in  this  are  only  half  as 
great  as  in  the  cistern  barometer ;  for  the 
tube  being  of  the  same  width  through- 
out, a  diminution  of  the  column  m  n 
amounting  to  one  inch  will  be  marked 
by  a  fall  of  half  an  inch  at  m  and  a  rise  of 
half  an  inch  at  n.  This  inconvenience 
may,  however,  be  remedied  by  having 
the  lower  branch  blown  into  a  wide  bulb ; 
but  as  it  is  very  difficult  to  procure  the 
bulb  to  be  blown  into  a  perfectly  regular 
shape,  this  enlargement  ot  the  bulb  is 
found  to  give  rise  to. inaccuracies. 

Fig.  3,  is  the  Wheel  Barometer,  pro- 
posed by  Hooke.  A  small  weight  floats 
on  the  surface  of  the  mercury  in  a  siphon 
barometer,  which  is  very  nearly  counter- 
poised by  another  weight,  w,  connected 
with  the  former  by  a  string  passing  over 
a  pulley,  p.  When  the  mercury  rises  at 
n,  the  weight  w  descends,  and  turns  the 
pulley.  An  index  attached  to  the  axle 
of  the  pulley  shows  on  a  dial  the  quantity 
of  revolution.  This  barometer,  though 
very  commonly  met  with,  is  a  mere  toy ; 
and  indicates  neither  the  absolute  height 
of  the  mercurial  column,  nor  its  varia- 
tions, with  sufficient  accuracy  to  be  of 
the  slightest  use  for  any  philosophical 
purpose  whatever.  Even  as  a  weather- 
glass, it  is  the  worst  of  all  the  common 
forms  of  the  barometer. 

Sir  Samuel  Moreland  proposed  to  en- 
large the  scale,  by  inclining  the  upper 
part  of  the  tube  so  as  to  form  a  consider- 
able angle  with  the  perpendicular.  By 
this  contrivance  the  scale  is  increased  in 
the  proportion  of  radius  to  the  cosine  of 
the  angle  of  inclination ;  but  the  friction 


34 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[bar 


on  the  sides  of  the  tube  is  greatly  in- 
creased, and  it  is  very  difficult  to  deter- 
mine the  exact  plane  of  the  top  of  the 
column  which  requires  to  be  read  off  on 
a  vertical  scale.  This  construction  is 
easily  conceived  without  a  diagram. 

We  shall  notice  two  other  forms  of  the 
barometer,  proposed  with  a  different  view 
from  that  of  enlarging  the  scale.  Fig.  4, 
is  a  modification  of  the  siphon  barometer 
proposed  by  Gay  Lussac.  It  differs  from 
the  common  form  in  this  respect,  that, 
after  the  tube  has  been  filled,  the  short 
branch  is  hermetically  closed  at  the  top, 
and  the  communication  with  the  atmos- 
phere takes  place  through  a  small  capil- 
lary hole  drilled  laterally  through  the 
tube  at  o,  so  fine  that  though  it  admits 
the  air  to  pass  freely,  it  prevents  the 
passage  of  the  mercury.  The  barometer 
is  thus  rendered  very  convenient  for  car- 
riage ;  but  notwithstanding  the  promising 
appearance  of  this  barometer,  it  has  been 
found,  particularly  in  travelling,  that  a 
portion  of  air  wiil  frequently  insinuate 
itself  through  the  mercury.  In  order  to 
prevent  the  possibility  of  the  accident, 
an  ingenious  modification  lias  been  made 
by  M.  Bunten,  a  Parisian  artist.  It  con- 
sists in  causing  the  part  of  the  tube  a  b 
to  terminate  in  a  very  fine  point,  and  to 
penetrate  to  some  depth  into  the  other 
part  c  o,  to  which  it  is  joined  at  c,  in  the 
manner  represented  in  Fig.  5.  Now  if  an 
air  bubble  from  the  end  <?,  which  com- 
municates with  the  atmosphere,  should 
find  its  way  through  the  bent  capillary 
tube,  it  will  pass  along  the  sides  of  the 
bulging  part,  and  instead  of  penetrating 
to  the  vacuum  at  a,  will  be  arrested  at  c, 
whence  it  is  easily  expelled  by  reversing 
the  barometer. 

None  of  the  contrivances  which  have 
been  described  for  increasing  the  range 
of  the  oscillations  have  been  found  to 
succeed  well  in  practice.  It  is  found  to 
be  decidedly  better  to  apply  minute  divi- 
sions, than  to  attempt  to  enlarge  the 
scale  ;  accordingly,  experimenters  now 
adhere  to  one  or  other  of  the  two  ancient 
forms,  the  cistern  barometer  and  the 
siphon  barometer.  The  height  of  the 
column  in  the  siphon  barometer  is  con- 
veniently measured  by  means  of  a  mov- 
able scale  attached  to  the  frame  which 
supports  the  tube ;  by  means  of  a  tangent 
screw,  the  scale  is  raised  or  lowered  till 
its  zero  coincides  exactly  with  the  surface 
of  the  mercury  in  the  lower  branch; 
and  with  the  assistance  of  a  vernier,  the 
height  can  be  read  off  to  the  hundredth 
or  two-hundredth  of  an  inch  with  suffi- 


cient precision.  The  scale  of  the  cistern 
barometer  is  usually  fixed,  and  the  bot- 
tom of  the  cistern  is  raised  or  lowered  by 
a  screw  till  the  surface  of  the  mercury  in 
it  coincides  with  the  zero  of  the  scale ; 
but  the  scale  may  be  movable,  and  its 
zero  brought  to  coincide  with  the  surface 
of  the  mercury  in  the  basin,  as  in  the 
former  case.  In  order  to  determine  when 
this  coincidence  takes  place,  various  ex- 
pedients may  be  had  recourse  to.  The 
most  usual  is  to  place  on  the  surface  of 
the  mercury  a  float  carrying  a  vertical 
needle,  some  point  on  which  answers  to 
a  fixed  point  on  the  scale,  and  the  coin- 
cidence obtains  when  the  two  points  are 
brought  into  the  same  level.  Another 
contrivance  to  effect  the  same  purpose 
was  employed  by  Fortin,  a  celebrated 
French  artist.  An  ivory  needle  is  at- 
tached to  the  scale,  pointing  downwards, 
and  having  its  point  exactly  in  the  same 
level  with  the  zero  of  the  scale.  The 
image  of  the  needle  is  clearly  reflected 
from  the  surface  of  the  mercury  in  the 
cistern,  and  the  cistern  is  raised  or  lower- 
ed till  the  point  of  the  needle  and  its 
image  precisely  coincide. 

In  order  to  construct  a  good  barometer, 
it  is  indispensably  necessary  that  the 
mercury  be  perfectly  free  from  impuri- 
ties, and  carefully  purged  of  air ;  tliis  is 
obtained  by  boiling  it.  The  particles  of 
air  and  moisture  which  cling  obstinately 
to  the  sides  of  the  tube  must  also  be  ex- 
pelled by  heat ;  the  mercury  must  then 
be  introduced  slowly  and  continuously 
in  a  hot  state,  and  while  the  tube  con- 
tinues hot.  Since  the  time  of  Deluc  it 
has  been  usual  to  boil  the  mercury  in  the 
tube  before  inverting  it  and  forming  the 
vacuum  •  but  doubts  now  begin  to  be  en- 
tertained among  the  most  skilful  makers 
of  the  expediency  of  this  very  trouble- 
some process.  The  mercury  is  partially 
oxydated  by  boiling,  and  a  thin  crust 
formed,  which  keeps  the  column  sus- 
pended at  a  greater  height,  and  obstructs 
the  freedom  of  the  motion.  It  is  impor- 
tant that  the  diameter  of  the  tube  be  not 
very  small ;  for  it  is  found  that  the  mer- 
cury moves  with  more  freedom  in  a  tube 
of  considerable  width,  the  oscillations 
following  the  atmospheric  changes  with 
more  promptitude  than  in  one  of  smaller 
dimensions ;  besides  which,  there  is  less 
disturbance  from  capillary  attraction. 
The  interior  diameter  should  in  every 
case  exceed  one-fourth  of  an  inch. 

The  value  of  the  barometer  as  a  scien- 
tific instrument  depends  on  the  purity  of 
the  mercury,  and  the  total  exclusion  of 


bar] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


35 


atmospheric  air.  By  proper  care  in  the 
construction,  it  is,  perhaps,  possible  to 
expel  every  particle  of  air  from  tho  mer- 
cury and  the  interior  of  the  tube  when 
the"  barometer  is  made ;  but  it  seems 
doubtful  if,  by  any  means  whatever,  it 
can  be  preserved  for  a  considerable  length 
of  time  in  this  state.  The  most  carefully 
constructed  barometers  are  liable  to  a 
slow  and  gradual  deterioration  by  the  in- 
trusion ot  air,  which  has  been  supposed 
to  insinuate  itself  between  the  metal  and 
the  tube,  and  not  through  the  mercury. 
To  obviate  this  inconvenience  Professor 
Daniell  conceived  the  ingenious  idea  of 
fixing  to  the  open  end  of  the  tube  of  the 
cistern  barometer  a  substance  having  a 
greater  affinity  than  glass  for  mercury. 
" I  caused,"  says  he,  "a  small  thin  piece 
of  platinum  tube  to  be  made,  about  the 
third  of  an  inch  in  length,  and  of  the 
diameter  of  the  glass  tube ;  this  was  care- 
fully welded  to  its  open  end,  so  that  the 
barometer  tube  terminated  in  a  ring  of 
platinum.  The  tube  was  filled  and  boiled 
as  usual,  and  the  infiltration  of  air  was_ 
completely  prevented  by  the  adhesion  of 
the  mercury  both  to  the  interior  and  ex- 
terior surface  of  the  platinum  guard.  I 
have  no  doubt  that  a  mere  ring  of  wire 
welded,  or  even  cemented,  upon  the  ex- 
terior surface  of  the  glass,  which  would 
be  a  much  easier  and  less  expensive 
operation,  would  be  a  sufficient  protec- 
tion, as  the  slightest  line  of  perfect  con- 
tact must  effectually  arrest  the  passage 
of  the  air" 

In  all  barometic  observations  there  are, 
in  general,  two  essential  corrections  to  be 
made  ;  one  for  the  capillarity  or  depres- 
sion of  the  mercury  in  the  tube,  ana  the 
other  for  temperature.  Pure  mercury  in 
a  glass  tube  always  assumes  a  convex 
surface.  The  following  are  the  correc- 
tions for  tubes  of  different  diameters,  ac- 
cording to  the  theory  of  Mr.  Ivory. 


Diam.  of  Tube. 
Inches. 

•to   -  - 

•15    -  - 

•20    -  - 

•25    -  - 

•30     -  - 

•35     -  - 


Depression. 
Inches. 

•1403. 
•0863. 
•0581. 
•0407. 
•0292. 
•0211. 


Diam.  of  Tube. 

Depression 
Inches. 

Inches. 

•40    -     - 

•0153. 

•45     -    - 

•0112. 

•50     -    - 

•0083. 

•60    -    - 

•0044, 

•70    -    - 

•0023. 

•80    -    - 

•0012. 

These  corrections,  which  must  always 
be  applied  to  cistern  barometers,  show 
that  wide  tubes  ought  to  be  preferred ; 
in  fact,  when  the  diameter  ot  the  tube 
exceeds  half  an  inch,  they  may  be  safely 
omitted.  In  siphon  barometers  having 
both  branches  of  the  same  diameter,  the 


depression  is  equal  at  both  ends  ;  conse- 
quently the  effect  is  destroyed,  and  no 
correction  is  required.  This  is  a  consi- 
derable advantage ;  for  notwithstanding 
the  most  elaborate  calculations,  some  un- 
certainty must  always  remain  with  re- 
gard to  the  exact  amount  of  the  capillary 
repulsion. 

The  correction  for  the  temperature, 
which  is  the  most  important,  depends  on 
the  expansion  of  the  mercury,  and  the 
expansion  of  the  scale  on  which  the  divi- 
sions are  marked.  If  we  make  a  =  the 
height  of  the  thermometer  in  degrees 
above  the  freezing  point,  x  =  the  frac- 
tional part  of  its  bulk  which  mercury  ex- 
Eands  for  one  degree  of  heat  on  Fahren- 
eit's  scale,  y  —  the  fractional  part  of  its 
length  by  which  the  scale  increases,  h  = 
the  observed  height  of  the  barometer; 
then  the  height  which  would  have  been 
observed  had  the  thermometer  stood  at 
the  freezing  point  is 

h  —  h  a(x — y). 

The  expansion  of  mercury  in  part  of  its 
bulk  is  -0001001.  The  scale  is  generally 
of  some  mixed  metal  of  which  the  expan- 
sion is  not  very  well  ascertained:  sup- 
posing it  to  be  equal  to  that  of  copper,  the 
expansion  would  be  *0000096 ;  therefore 
it  will  be  sufficiently  accurate  to  neglect 
the  temperature  of  the  scale,  and  assume 
that  of  the  mercury  to  be  "0001.  Hence 
the  following  practical  rule  for  reducing 
an  observed  height  to  the  corresponding 
height  at  the  temperature  of  the  freezing 
point :    "  Subtract    the   ten-thousandth 

Sart  of  the  observed  altitude  for  every 
egree  of  Fahrenheit  above  32."  Sup- 
pose the  thermometer  54°  and  the  baro- 
meter 30  inches,  the  correction  will  be 
(54—32)  X  30  X  '0001  =  -066,  to  be  sub- 
tracted from  30  inches.  In  order  to  find 
the  value  of  this  correction  a  thermome- 
ter must  be  attached  to  the  barometer, 
and  observed  at  the  same  time.  A  table, 
showing  the  correction  for  temperature 
for  every  degree  of  Fahrenheit  from  30° 
to  90°,  and  for  every  difference  of  half  an 
inch  in  the  height  of  the  mercury  from 
28  to  30*5  inches,  was  constructed  by 
Professor  Schumacher,  and  is  given  by 
Mr.  Baily  in  the  Phil.  Trans,  for  1837. 

Cause  of  the  variations  of  the  barometer. 
— Various  theories  have  been  proposed 
to  account  for  those  frequent  atmosphe- 
rical changes  which  cause  the  rise  and 
fall  of  the  barometer,  but  none  of  them 
can  be  regarded  as  very  satisfactory. 
Whatever  tends  to  increase  or  diminish 
the  vertical  pressure  will  obviously  cause 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[BA5 


the  barometei  to  rise  or  fall ;  but  the  ver-  ; 
tical  pressure  may  be  increased  either  by 
an  influx  of  winds  and  the  accumulation  j 
of  air  at  any  place,  or  by  a  diminution  of  j 
the  elasticity  of  the  atmosphere.     The  ! 
presence  of  heat  or  of  moisture  augments  j 
the  elasticity,  and  consequently  reduces  j 
the  weight  of  the  vertical  column.  During  j 
the  prevalence  of  northerly  and  easterly  j 
winds   the   barometer  stands  high,  the  j 
elasticity  being  diminished  by  the  cold,  j 
But  the  real  difficulty,  Professor  Leslie  \ 
remarks,    "consists   in   explaining  why  \ 
the  variations  of  the  barometer  should  be 
greater  in  the  high  latitudes  than  be- 
tween the  tropics,  and  why  they  should 
exceed  in  all  cases  the  quantities  which 
calculation  might  assign.  The  only  mode, 
perhaps,  of  removing  the  difficulty  is  to 
take  into  consideration  the  comparative 
slowness  with  which  any  force  is  propa- 
gated through  the  vast  body  of  the  at- 
mosphere.    An  inequality  may  continue 
to  accumulate    in  one  spot  before  the 
counterbalancing  influence  of  the  distant 
portions  of  the  aerial  influence  can  arrive 
to  modify  the  result.     In  the  higher  lati- 
tudes, the  narrow  circle  of  air  may  be 
considered  as  in  some  measure  insulated 
from  the  expanded  ocean  of  atmosphere ; 
and  hence,  perhaps,  the  variations  of  the 
barometer   are  concentrated  there,   and 
swelled  beyond  the  due  proportion." 

Uses  of  "the  barometer. — The  barometer 
is  an  instrument  of  great  importance  in 
astronomy,  its  indications  forming  an 
essential  element  in  determining  the 
amount  of  atmospheric  refraction.  It  is 
also,  on  account  of  its  application  to  the 
measurement  of  altitudes,  indispensable 
in  all  researches  connected  with  the  cli- 
mate. The  purpose  for  which  it  is  most 
commonly  sought  after,  is  to  prognosti- 
cate the  state  of  the  weather.  On  land 
this  is  perhaps  the  least  important  of  its 
applications,  but  the  case  is  widely  dif- 
ferent at  sea. 

No  certain  rules  can  be  laid  down  for 
prognosticating  the  state  of  the  weather 
from  the  barometer.  The  following  are 
probably  of  as  general  application  as  any 
that  can  be  given.  It  is  always  to  be  re- 
membered that  what  the  barometer  ac- 
tually shows  is  the  present  pressure  of 
the  atmosphere;  and  that  its  variations 
correspond  to  atmospherical  changes 
which  have  already  taken  place,  the 
effects  of  which  may  follow  their  cause 
at  a  greater  or  less  interval. 

1.  After  a  continunnce  of  dry  weather, 
if  the  barometer  begins  to  fall  slowly  and 
steadily,  rain  will  certainly  ensue ;  but  if 


the  fine  weather  has  been  of  long  dura- 
tion, the  mercury  may  fall  for  two  or 
three  days  before  any  perceptible  change 
takes  place,  and  the  longer  time  elapses 
before  the  rain  comes,  the  longer  the  wet 
weather  is  likely  to  last. 

2.  Conversely,  if  after  a  great  deal  of 
wet  weather,  with  the  barometer  below 
its  mean  height,  the  mercury  begins  to 
rise  steadily  and  slowly,  fine  weather  will 
come,  though  two  or  three  wet  days  may 
first  elapse ;  and  the  fine  weather  will  be 
more  permanent  in  proportion  to  the 
length  of  time  that  passes  before  the  per- 
ceptible change  takes  place. 

3.  On  either  of  the  two  foregoing  sup- 
positions, if  the  change  immediately  en- 
sues on  the  motion  of  the  mercury,  the 
change  will  not  be  permanent. 

4.  If  the  barometer  rise  slowly  and 
steadily  for  two  days  together  or  more, 
fine  weather  will  come,  though  for  those 
two  days  it  may  rain  incessantly,  and  the 
reverse ;  but  if  the  barometer  rise  for 
two  days  or  more  during  rain,  and  then 
on  the  appearance  of  fine  weather  begins 
to  fall  again,  that  fine  weather  will  be 
very  transient,  and  vice  versa. 

5.  A  sudden  fall  of  the  barometer  in 
the  spring  or  autumn  indicates  wind ;  in 
the  summer,  during  very  hot  weather,  a 
thunderstorm  may  be  expected ;  in  win- 
ter, a  sudden  fall  after  frost  of  some  con- 
tinuance indicates  a  change  of  wind,  with 
thaw  and  rain  ;  but  in  a  continued  frost, 
a  rise  of  the  mercuiy  indicates  approach- 
ing snow. 

6.  No  rapid  fluctuations  of  the  baro- 
meter are  to  be  interpreted  as  indicating 
either  dry  or  wet  weather  of  any  con- 
tinuance ;  it  is  only  the  slow,  steady,  and 
continued  rise  or  fall  that  is  to  be  at- 
tended to  in  this  respect. 

7.  A  rise  of  the  mercury  late  in  the 
autumn,  after  a  long  continuance  of  wet 
and  windy  weather,  generally  indicates 
a  change  of  wind  to  the  northern  quar- 
ters, and  the  approach  of  frost. 

BARYTO  CALCITE.  A  mineral  oc- 
curring both  massive  and  crystallized  in 
oblique  rhombic  prisms.  It  contains  66 
per  cent,  of  carbonate  baryta  and  34  per 
cent,  of  carbonate  <  >f  lime. 

BASALT.  A  common  species  of  trap. 
Essentially  composed  of  felspar  and  au- 
gite,  of  a  compact  texture,  and  dark-green 
gray  or  black  color  :  often  found  crystal- 
lized in  pentagonal  or  six-sided  figures, 
as  those  in  the  Giants'  Causeway  and  tho 
Island  of  Staffa  are  magnificent  exam- 
ples. The  Palisades  on  the  Hudson  rive* 
are  of  basalt. 


CYCIOPEDIA    OF    THE    USEFUL    ARTS. 


37 


BASE.  In  chemistry  the  substance 
with  which  an  acid  is  combined:  thus 
in  the  sulphate  of  iron,  iron  is  the  base 
united  with  sulphuric  acid.  Almost  all 
oxides  of  metals  are  bases. 

BASSORINE.  A  modification  of  gum, 
originally  found  by  Vauquelin  in  gum 
bassora.  It  is  semi-transparent,  and 
forms  a  thick  mucilage  with  water  with- 
out dissolving :  an  addition  of  a  little 
nitric  or  muriatic  acid  aids  its  solubility 
very  much. 

BATTEN.  Wooden  scantling  from 
two  to  six  inches  broad,  and  from  one  to 
two  inches  thick,  used  in  walls  to  secure 
the  laths  over  which  the  plaster  is  laid. 

BAY  SALT.  A  large  grained  salt  ob- 
tained by  the  spontaneous  evaporation  of 
sea  water  in  large  shallow  pits  exposed 
to  the  full  action  of  sun  and  air. 

BDELLIUM.  An  African  gum  resin 
of  a  dark  brown  color :  common  in  sam- 
ples of  myrrh. 

BEAM.  A  horizontal  piece  of  timber 
used  for  resisting  the  strain  of  a  weight ; 
as  a  tie-beam,  which  acts  like  a  string  or 
chain  by  its  tension;  a  straining-piece 
where  it  acts  by  compression  ;  or  a  bres- 
summer  where  it  bears  a  resisting  weight. 

BEEK.  Wine  made  from  grain,  chiefly 
by  fermenting  an  infusion  of  barley, 
malt,  and  of  hops,  and  bears  different 
names  according  to  the  color  and  the 
strength.  Wheat  and  maize  are  suscepti- 
ble of  undergoing  a  like  change  with 
barley.  Oats  and  rice  also  are  capable  of 
producing  beer ;  and  many  other  vegeta- 
ble bitters  arc  substituted  for  the  hop. 
The  objects  in  view  in  this  manufacture 
are  to  form  sugar,  and  consequently  the 
alcoholic  portion  of  the  liquor,  the  other 
to  communicate  a  particular  flavor,  and 
assist  in  its  preservation.  The  first  stage 
is  to  convert  the  barley  into  malt,  by 
making  the  grain  germinate  up  to  a  cer- 
tain point,  when  a  peculiar  azotized  sub- 
stance called  diastase  is  formed,  which 
possesses  the  remarkable  property  of 
converting  the  starch  into  a  fermentible 
BUgar,  resembling  grape-sugar.  This 
change  does  not  take  place  at  once,  for 
the  starch  is  first  changed  into  a  gummy 
mucilaginous  substance  called  dextrin. 
This  substance  does  not  ferment  on  the 
addition  of  yeast;  but  by  the  action  of 
diastase  it  is  readily  converted  into  starch- 
sugar,  which  is  'fermentible.  This  is 
generally  a  distinct  operation  from  that 
of  brewing,  and  consists  of  four  pro- 
cesses, namely,  steeping,  couching,  floor- 
ing, and  kiln-drying.  In  steeping,  the 
malt  is  placed  in  sunk  cisterns,  sprinkled 


with  water  so  as  barely  to  cover  it,  and  let 
lie  for  about  40  hours.  The  barley  im- 
bibes moisture  and  increases  in  bulk  ;  it 
gives  out  carbonic  acid,  which  dissolves 
in  the  water ;  some  of  the  husk  colors 
the  water  also.  The  grain  becomes 
whiter  and  so  soft  that  the  two  ends  of  a 
grain  can  be  squeezed  between  the  finger 
and  thumb ;  the  water  is  then  drained 
off;  it  is  then  heaped  or  couched.  When 
it  warms  and  begins  to  germinate,  the 
grain  absorbs  oxygen  and  gives  out  car- 
bonic acid,  and  the  temperature  rises  to 
90°. 

The  germination  of  the  malt  is  now 
stopped  by  drying  on  a  kiln,  which  con- 
sists of  a  chamber,  floored  with  an  iron 
plate,  full  of  holes,  and  furnished  with  a 
vent  in  the  roof  for  the  escape  of  fumes. 
Below  this  floor  is  a  furnace  containing 
charcoal  or  coke,  the  heat  of  which  as- 
cends through  the  malt. 

Pale  amber  and  brown  malt  can  be  pro- 
duced from  the  same  kind  of  malt,  by 
varying  the  temperature  of  the  drying. 
Pale  malt  is  dried  at  the  proper  temper- 
ature, and  produces  the  best  beer  ;  the 
other  varieties  are  scorched  and  charred. 
The  brown  malt  gives  a  bitter  taste,  and 
being  less  alcoholic,  became  a  more  fa- 
vorite drink  with  the  laboring  classes  of 
London  :  and  hence  its  name  "  porter." 
The  malt  is  then  ground  or  crushed  into 
coarse  powder,  and  then  passed  into  a 
mash  tun  containing  water  heated  up  to 
170°.  Here  it  digests  on  the  malt  till  all 
the  sugar  is  extracted,  when  the  liquor, 
now  called  worts,  is  drawn  off.  The 
grain  receives  three  waters,  which,  when 
drawn  off,  are  mixed  together.  The  first 
wort  is  sometimes  set  aside  for  superior 
ales,  and  the  second  and  third  for  inferior 
beers.  The  malster  regulates  the  strength 
of  his  worts  by  an  instrument  called  the 
saccharometer,  a  variety  of  hydrometer. 

The  worts  are  next  concentrated  by 
boiling,  and  cleared  of  the  vegetable  al- 
bumen which  coagulates.  The  hops  are 
added  in  this  vessel,  and  are  kept  stirred, 
so  as  not  to  lie  on  the  bottom.  The 
quantity  of  hops  added  depends  on  the 
quality  of  the  beer,  the  season,  and  cli- 
mate to  which  it  may  be  exported.  In 
warm  weather  a  larger  portion  is  added. 
In  strong  English  beer  4£  lbs.  of  hops  is 
allowed  for  a  quarter  of  malt :  for  ale  and 
porter  1  lb.  of  hops  to  a  bushel  of  malt. 
The  boiling  being  completed,  the  liquid 
is  now  cooled  suddenly.  It  is  then  passed 
into  the  fermenting  tun,  and  yeast  added. 
One  gallon  of  yeast  generally  sets  100 
gallons  of  wort  in  active  fermentation; 


38 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


|B*JR 


by  this  latter  action  the  sugar  is  changed 
into  alcohol.  Before  this  is  fully  com- 
pleted the  worts  are  racked  off  into  large 
hogsheads,  with  the  bungholes  open, 
where  fermentation  is  allowed  to  complete 
itself.  By  this  means  no  vinegar  is  pro- 
duced, which  would  be  the  case  were  the 
process  to  be  completed  in  open  vessels. 
The  fermentation  over,  the  beer  is  pumped 
up  into  store-vats  of  great  size,  where  it 
is  kept  until  required  to  be  drawn  off  for 
consumption.  The  casks  are  bunged 
down  tightly.  The  beer  cleanses  itself  j 
in  these  vats,  throwing  down  a  scum  of 
flocculent  matter.  Isinglass,  or  finings,  is 
sometimes  added  for  this  purpose,  to  ex- 
pedite the  clarification. 

BEET.  The  sweet  succulent  root  of 
Beta  vulgaris,  a  Chenopodiaceous  plant  of 
biennial  duration.  It  is  used  in  the  win- 
ter as  a  salad,  for  which  purpose  the  red 
and  yellow  beets  of  Castelnaudari  are  the 
best ;  for  the  food  of  cattle,  under  the 
name  of  mangel-wurzel ;  and  for  the  ex- 
traction of  sugar :  for  the  last  object  a 
white-rooted  variety  with  a  purple  crown 
is  the  most  esteemed.  Sea  beet,  Beta 
maritima,  is  a  well  known  and  excellent 
substitute  for  spinach. 

To  Napoleon  is  due  the  merit  of  having 
established  the  extraction  of  sugar  from 
beet  as  a  branch  of  manufacture,  which 
is  now  in  so  nourishing  a  condition  in 
France  as  to  gradually  exclude  the  Colo- 
nial sugar  in  the  French  market.  Its  ma- 
nufacture was  twice  attempted  in  Ireland 
with  such  success,  that  the  West  India 
planters  had  their  jealousy  aroused :  and 
their  influence  was  such,  that  a  heavy 
prohibitory  duty  was  laid  on  beet  sugar, 
which  crushed  the  trade ;  it  is  now, 
however,  removed,  and  the  manufacture 
of  sugar  from  beet,  will,  in  a  few  years, 
in  temperate  latitudes,  exclude  that  of 
the  cane  and  the  maple.  (For  a  descrip- 
tion of  the  process,  see  Sugar.) 

BELL  METAL.  An  alloy  of  80  parts 
of  copper  and  20  of  tin.  The  Indian 
gong  metal  is  a  similar  alloy.  An  English 
Dell  metal  analyzed  by  Dr.  Thomson  was 
found  to  consist  of  800  copper,  101  tin, 
56  zinc,  and  43  leajf.  Small  shrill  bells 
generally  contain  zinc. 

BELLOWS.  A  machine  contrived  to 
propel  air  through  a  tube  or  orifice.  It 
is  used  for  blowing  fires,  supplying  the 
pipes  of  organs,  and  other  purposes,  and 
is  constructed  according  to  various  forms ; 
but  the  principle  is  the  same  in  all  of 
them.  The  dimensions  of  a  space  in 
which  air  is  confined  are  contracted ;  the 
air  being  permitted  to  escape  only  at  a 


small  opening,  rushes  out  with  a  velocity 
proportional  to  the  pressure  and  to  the 
smallness  of  the  opening.  (For  improved 
bellows  and  blowing  machines,  see  Metal- 
lurgy.) 

BEN  NUTS.  The  seeds  of  an  Arabian 
plant  called  moringa  aptera  •  they  yield 
an  oil  called  oil  of  ben,  and  have  been 
employed  in  syphilitic  diseases. 

BEN,  OIL  OF.  The  expressed  oil  of 
the  nut  of  the  marimba  aptera.  This  oil 
is  remarkable  for  not  becoming  rancid  by 
age ;  and  as  it  is  perfectly  insipid  and  in- 
odorous, it  is  used  for  extracting  the  fra- 
grancy  of  certain  flowers,  such  as  jessa- 
min, orange,  &c.  The  same  tree  fur- 
nishes the  lignum  nephriticum,  supposed 
to  be  useful  in  certain  affections  of  the 
kidneys. 

BENGAL  STKIPES.  Ginghams,  a 
cotton  fabric  woven  with  colored  stripes. 

BENZOIC  ACID.  A  constituent  of 
many  balsams,  generally  obtained  by 
heating  benzoin  upon  a  shallow  iron  pan, 
surmounted  by  a  frame  capped  with  car- 
tridge paper,  upon  which  the  acid  sub- 
limes at  a  gentle  heat.  It  may  also  be 
obtained  by  boiling  benzoin  with  slaked 
lime,  and  decomposing  the  newly-formed 
benzoate  of  lime  by  nydrochloric  acid ; 
it  is  in  either  case  obtained  in  white 
crystalline  plates.  Its  chemical  composi- 
tion is  C14  H5  O3,  and  is  classed  as  the 
oxide  of  a  supposed  radical  benzule. 
Benzoic  acid  melts  at  212°,  dissolves  in 
200  parts  of  cold  and  25  parts  of  boiling 
water,  in  twice  its  weight  of  alcohol, 
and  freely  in  ether,  fats,  and  volatile 
oils.  It  is  an  ingredient  of  fumigating 
powders  and  pastiles.  It  enters  into  the 
composition  of  Friar's  balsam,  a  veteri- 
narv  medicine,  and  of  the  cosmetic  vir- 
gin's milk,  made  of  two  drachms  of  the  al- 
coholic solution  of  benzoin  with  one  pint 
of  rose  water. 

BENZOIN.  The  resinous  exudation 
of  the  styrax  benzoin,  a  tree  which  is  a  na- 
tive of  Sumatra.  Benzoin  is  a  combina- 
tion of  resin  and  benzoic  acid.  It  has  a 
mottled  or  amygdaloid  texture,  and  is 
composed  of  a  mixture  of  brown  and 
white  parts.  It  has  a  fragrant  odor,  and 
is  much  used  in  perfumery  and  varnishes. 

BERBEREN.  A  yellow  bitter  princi- 
ple, contained  in  the  alcoholic  extract  of 
the  root  of  the  barberry  tree. 

BERBERRY.  (Lat,  bcrberis.)  A  spiny 
shrubby  plant,  bearing  yellow  flowers, 
and  succulent  one-celled  fruit  growing  in 
racemes.  It  is  one  of  a  genus  in  which 
the  fruit  is  universally  fleshy  and  acid, 
although  often  less  so  than  m  the  com- 


bis] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


39 


mon  kind  (berberis  vulgaris.)  Some  of 
the  species  nave  pinnated  leaves,  many 
are  evergreens,  and  several  have  a  black 
fruit ;  even  the  common  sort  has  a  variety 
of  this  description,  as  well  as  others  with 
pale  yellow  and  stoneless  fruit.  There  is 
an  idea  among  people  in  the  country,  that 
a  berberry  bush  brings  blight  to  a  wheat 
field:  but  the  parasitical  fungus  which 
attacks  the  berberry  is  altogether  differ- 
ent from  that  which  produces  the  mildew 
of  wheat,  which  cannot  possibly  be  com- 
municated by  the  one  to  the  other.  It 
gives  a  yellow  dye  to  leather. 

BERGAMOT,  ESSENCE  OF.  The  es- 
sential oil  of  the  rind  of  a  small  pear- 
shaped  fruit,  the  produce  of  the  citrus 
limetta  bergamium.  It  is  much  used  as  a 
perfume,  and  apt  to  be  adulterated  with 
the  oils  of  orange  and  lemon  peel,  and 
with  alcohol. 

BEVEL.  In  architecture,  an  instru- 
ment for  taking  angles.  One  side  of  a 
solid  body  is  said  to  be  bevelled  with  re- 
spect to  another  when  the  angle  con- 
tained between  their  two  sides  is  greater 
or  less  than  a  right  angle. 

BEVEL  ANGLE.  A  term  used  among 
artificers  to  denote  an  angle  which  is 
neither  a  right  angle  nor  half  a  right 
angle. 

BEVEL  GEEE.  In  mechanics,  a  spe- 
cies of  wheelwork,  in  which  the  axles  of 
two  wheels  working  into  each  other  are 
neither  parallel  nor  perpendicular,  but 
inclined  to  one  another  in  a  certain  angle. 
"Wheels  of  this  kind  are  also  called  coni- 
cal wheels,  because  their  teeth  may  be 
regarded  as  cut  in  the  frustrum  of  a 
cone. 

BILE.  A  fluid  secreted  in  the  liver, 
of  a  yellow  color,  and  a  nauseous  taste, 
compounded  of  sweet  and  bitter;  it  sinks 
in  water,  and  mixes  with  it  in  all  pro- 
portions ;  it  is  slightly  alkaline,  and  feels 
soapy.  It  contains  a  peculiar  bitter  prin- 
ciple, which  lias  been  called  picromel, 
and  a  little  free  soda  and  saline  matters. 
According  to  Berzelius,  the  solid  con- 
stituents of  bile  amount  to  about  one- 
tenth  of  its  weight. 

Modern  chemistry  regards  bile  as  a 
soda  soap,  and  on  this  account  ox,  gall  or 
bile  is  used  by  water-color  painters  and 
scourers  of  cloth,  but  it  requires  to  be 
freed  from  its  green  color :  this  is  accom- 
plished by  letting  it  settle,  and  then  eva- 
porating it  in  a  water  bath  to  thickness, 
and  letting  it  dry  into  thin  cakes.  A  little 
alum  added  to  a  solution  of  gall,  removes 
the  color  after  lying  together  for  three 
months..  Prepared  gall  gives  solidity  to 


colors  and  paints,  either  by  being  mixed 
with  them,  or  passed  over  them  on  pa- 
paper.  Mixed  with  gum  it  thickens  the 
colors,  prevents  the  gum  cracking  and 
the  colors  from  running  into  each  other. 
It  heightens  the  tint  of  carmine,  ultra- 
marine, green,  and  the  most  delicate  co- 
lors, and  spreads  them  smoothly  on 
ivory  and  paper.  Coated  over  black  lead 
or  crayon  drawing,  it  keeps  them  from 
being  rubbed  off;  removes  grease  spots 
from  ivory,  paper;  and  cloth ;  and  a  small 
portion  added  to  ink,  renders  it  fluid. 

BINNACLE.  The  case  or  stand  in 
which  the  steering  compass  is  placed  ;  it 
is  fixed  near  the  tiller  or  wheel.  At  night 
the  compass  is  illuminated  by  a  lamp 
placed  over  it. 

BINOCLE,  or  BINOCULAR  TELE- 
SCOPE. A  telescope  to  which  both  eyes 
may  be  applied  at  once,  and  in  which, 
consequently,  an  object  may  be  observed 
with  both  eyes  at  the  same  time. 

BIRDLIME.  A  glutinous  substance 
extracted  by  boiling  the  bark  of  the  holly 
tree  :  a  similar  substance  may  be  obtain- 
ed from  misletoe,  from  the  young  shoots 
of  elder,  and  some  other  plants.  It  is 
much  used  in  India  for  destroying  in- 
sects. It  contains  resin,  mucilage,  free 
acid,  and  coloring  matter. 

BISCUIT.  In  sculpture,  a  species  of 
porcelain,  of  which  groups  and  figures  in 
miniature  are  formed,  which  are  twice 
passed  through  the  furnace  or  oven.  It 
is  executed  without  glaze  upon  it.  In 
pottery,  this  term  is  applied  to  earthen- 
ware and  porcelain,  after  it  has  been 
hardened  in  the  fire,  and  before  it  re- 
ceives the  glaze :  in  this  state  it  is  per- 
meable to  water.  On  which  account  it  is 
now  largely  used  as  porous  cells  for  elec- 
trotype purposes. 

Biscuit.  An  unfermented  bread, 
which,  when  well  prepared,  may  be  kept 
for  a  long  time ;  and  hence  valuable  as  a 
common  form  of  bread  at  sea.  In  Eng- 
land, the  sea  biscuit  manufacture  by  hand 
for  government-contract  has  been  sus- 

? ended  by  the  machinery  invented  by 
'.  T.  Grant,  Esq.,  of  the  Royal  Clarence 
yard,  which  is  this  :  the  meal  or  flour  is 
conveyed  into  a  hollow  cylinder  four  or 
five  feet  long  and  about  three  feet  in  dia- 
meter, and  the  water,  the  quantity  of 
which  is  regulated  by  a  gauge,  is  ad- 
mitted to  it;  a  shaft,  armed  with  long 
knives,  works  rapidly  round  in  the  cylin- 
der with  such  astonishing  effect,  that  in 
the  short  space  of  three  minutes,  340  lbs. 
of  dough  are  produced,  infinitely  better 
made  than  that  mixed  by  the  naked  arms 


40 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


b 


of  a  man.  The  dough  is  removed  from 
the  cylinder  and  placed  under  the  break- 
ing-rollers ;  these  latter,  which  perform 
the  office  of  kneading,  are  two  m  num- 
ber, and  weigh  15  cwt.  each ;  they  are 
rolled  to  and  fro  over  the  surface  of  the 
dough  by  means  of  machinery,  and  in 
five  minutes  the  dough  is  perfectly  knead- 
ed. The  sheet  of  dough,  which  is  about 
two  inches  thick,  is  then  cut  into  pieces 
half  a  yard  square,  which  pass  under  a 
second  set  of  rollers,  by  which  each  piece 
is  extended  to  the  size  of  six  feet  by  three, 
and  reduced  to  the  proper  thickness  for 
biscuits.  The  sheet  of  dough  is  now  to 
be  cut  up  into  biscuits,  and  no  part  of 
the  operation  is  more  beautiful  than  the 
mode  by  which  it  is  accomplished.  The 
dough  is  brought  under  a  stamping  or 
cutting-out  press,  similar  in  effect,  but 
not  in  detail,  to  that  by  which  circular 
pieces  for  coins  are  cut  out  of  a  sheet  of 
metal.  A  series  of  sharp  knives  are  so 
arranged  that,  by  one  movement,  they 
cut  out  of  a  piece*  of  dough  a  yard  square 
about  sixty  hexagonal  biscuits.  The  rea- 
son for  a  hexagonal  (six-sided)  shape  is, 
that  not  a  particle  of  waste  is  thereby- 
occasioned,  as  the  sides  of  the  hexagonals 
accurately  fit  into  those  of  the  adjoining 
biscuits  ;  whereas  circular  pieces  cut  out 
of  a  large  surface  always  leave  vacant 
spaces  between.  That  a  flat  sheet  can  be 
divided  into  hexagonal  pieces  without 
any  waste  of  material  is  obvious. 

Each  biscuit  is  stamped  with  the 
queen's  mark,  as  well  as  punctured  with 
holes,  by  the  same  movement  which  cuts 
it  out  of  the  piece  of  dough.  The  hexa- 
gonal cutters  do  not  sever  the  biscuits 
completely  asunder-  so  that  a  whole 
sheet  of  them  can  be  put  into  the  oven 
at  once  on  a  large  peel  or  shovel  adapted 
for  the  purpose.  About  fifteen  minutes 
are  sufficient  to  bake  them ;  they  are 
then  withdrawn  and  broken  asunder  by 
the  hand. 

The  corn  for  the  biscuits  is  purchased 
at  the  markets,  and  cleaned,  ground,  and 
dressed  at  the  government  mills.  In 
quality  it  is  a  mixture  of  fine  flour  and 
middlings,  the  bran  and  pollard  being 
removed,  The  ovens  for  baking  are 
formed  of  fire-brick  and  tile,  with  an  area 
of  about  160  feet.  About  112  lbs.  weight 
of  biscuits  are  put  into  the  ovens  at  once. 
This  is  called  a  suit,  and  is  reduced  to 
about  110  lbs.  by  the  baking.  From 
twelve  to  sixteen  suits  can  be  baked  in 
each  oven  every  day,  or  after  the  rate  of 
224  lbs.  per  hour.  The  men  engaged 
are  dressed  in  clean  check  shirts  and 


white  linen  trowsers,  apron,  and  cap; 
and  every  endeavor  is  made  to  observe 
the  most  scrupulous  cleanliness :  450  lbs. 
of  dough  may  be  mixed  by  the  machine 
in  four  minutes,  and  kneaded  in  five  or 
six  mhmtes ;  we  need  hardly  say  how 
much  quicker  this  is  than  men's  hands 
could  effect  it.  The  biscuits  are  cut  out 
and  stamped  sixty  at  a  time,  instead  of 
singly  :  besides  the  time  thus  saved,  the 
biscuits  become  more  equally  baked,  by 
the  oven  being  more  speedily  filled.  The 
nine  ovens  at  Gosport  used  to  employ  45 
men  to  produce  about  1,500  lbs.  of  bis- 
cuit per  hour  ;  16  men  and  boys  will 
now  produce,  by  the  same  number  of 
ovens,  2,240  lbs.  of  biscuit  (one  ton)  per 
hour. 

The  comparative  expense  is  thus  stat- 
ed: Under  the  old  system,  wages,  and 
wear  and  tear  of  utensils,  cost  about  1*.  €>d. 
per  cwt.  of  biscuit :  under  the  new  sys- 
tem, the  cost  is  5d.  British  money. 

BISMUTH.  A  brittle,  yellowish-white 
metal,  of  crystalline  texture.  Its  specific 
gravity  is  10 ;  it  fuses  at  476°,  and  at  a 
red  heat  it  sublimes  in  close  vessels.  II 
conducts  heat  less  perfectly  than  most  ol 
the  other  metals.  When  strongly  heat- 
ed it  burns  with  a  bluish  white  flame, 
and  is  rapidly  oxidized.  Its  equivalent 
upon  the  hydrogen  scale  is  71 ;  and  it 
forms  only  one  salifiable  oxide,  the  equi- 
valent of  which  is  79.  "When  nitrate  of 
bismuth  is  dropped  into  water,  a  white 
powder  is  thrown  down,  formerly  called 
magistery  of  bismuth  or  pearl  white :  it  is 
a  subnitrate.  This  is  used  as  a  cosmetic. 
A  brown  peroxide  of  bismuth  is  obtained 
by  fusing  the  protoxide  with  caustic 
potash.  Some  of  the  alloys  of  bismuth 
are  remarkable  for  their  fusibility :  a 
compound  of  8  parts  of  bismuth,  5  ot 
lead,  and  3  of  tin,  melts  in  boiling  water, 
and  is  commonly  called  fusible  mttal. 
The  ores  of  bismuth  are  not  common  ; 
but  it  occurs  native,  and  combined  with 
oxygen,  sulphur,  and  arsenic.  The  Ger- 
mans call  it  wismuth. 

Bismuth,  alloyed  with  lead  and  tin,  has 
been  used  as  the  patent  safety  plug  in 
steam  boilers  to  guard  against  explosion. 
It  was  supposed  that  at  a  high  tempera- 
ture, the  alloy  would  melt  and  allow  the 
steam  to  blow  itself  out.  This  has  not 
been  found  the  case,  for  this  alloy,  when 
exposed  a  long  time  to  the  action  oi 
steam,  undergoes  a  process  of  change  by 
which  the  more  fusible  alloy  is  melted 
out,  and  what  remains  is  so  hard  as  not 
to  fuse  :  after  the  explosion  of  boilers, 
these  plugs  have  been  found  unmelted. 


ble] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


41 


Fusible  metal  has  been  used  for  casts 
for  anatomical  preparations,  casts  from 
medals,  and  even  the  surfaces  of  wood 
and  paper.  Cake  moulds  for  toilet  soap 
manufacture,  are  made  of  this  metal. 

BITTERN.  The  mother  liquor  or  un- 
crystallized  residuum  of  salt  works,  so 
called  on  account  of  its  bitter  taste.  Chlo- 
ride of  magnesium  and  sulphate  of  mag- 
nesia, are  its  chief  ingredients. 

BLACK  LEAD.    (See  Plumbago.) 

BLACK  PIGMENT.  A  fine  lamp- 
black, obtained  in  England  by  burning  a 
thick  jet  of  coal  gas  with  a  small  quantity 
of  air,  by  which  its  carbon  is  deposited 
very  fine.  In  this  country  it  is  made  by 
the  combustion  of  oil  and  of  rosin,  car- 
ried on  incompletely.  This  fine  and  light 
black  is  used  in  the  manufacture  of  the 
better  quality  of  printing  ink. 

BLACKING.  An  article  prepared  in 
various  ways  for  polishing  shoes  and 
boots.  Each  manufacturer  has  his  own 
recipe,  in  which  ivory  black  or  some 
other  black  color,  oil,  and  vinegar,  with 
molasses,  are  the  principal  ingredients. 
The  following  is  the  mode  of  making  the 
waterproof  or  India-rubber  blacking : 

18  ounces  of  caoutchouc  are  to  be  dis- 
solved in  about  9  pounds  of  hot  rape  oil. 
To  this  solution  60  pounds  of  fine  ivory 
black  and  45  pounds  of  molasses  are  to 
be  added,  along  with  1  pound  of  finely- 
ground  gum  arabic,  previously  dissolved 
an  20  gallons  of  vinegar,  of  strength  No. 
24.  These  mixed  ingredients  are  to  be 
finely  triturated  in  a  paint-mill  till  the 
mixture  becomes  perfectly  smooth.  To 
this  varnish  12  pounds  of  sulphuric  acid 
are  to  be  now  added  in  small  successive 
quantities,  with  powerful  stirring  for  half 
an  hour.  The  blacking  thus  compounded 
is  allowed  to  stand  for  fourteen  days,  it 
being  stirred  half  an  hour  daily ;  at  the 
end  of  which  time,  3  pounds  of  finely 
ground  gum  arabic  are  added,  after  which 
the  stirring  is  repeated  half  an  hour  every 
day  for  fourteen  days  longer,  when  the 
liquid  blacking  is  ready  for  use. 

In  making  the  paste  blacking,  the  above 
quantity  of  India-rubber,  oil,  ivory  black, 
molasses,  and  gum  arabic,  may  be  used, 
the  latter  being  dissolved  in  only  12 
pounds  of  vinegar.  These  ingredients 
are  to  be  well  mixed,  and  then  ground 
together  in  a  mill  till  they  form  a  perfectly 
smooth  paste.  To  this  paste  12  pounds 
of  sulphuric  acid  are  to  be  added  in 
small  quantities  at  a  time,  with  powerful 
stirring,  which  is  to  be  continued  for 
half  an  hour  after  the  last  portion  of  the 
acid  has  been  introduced.    This  paste 


will  be  found  fit  for  use  in  about  seven 
days. 
BLANKET.     (See  Woollens.) 
BLAST  FURNACE.    (See  Ikon.) 
BLEACHING.    The  art  of  depriving 
stuffs  and  goods  of  the  coloring  matters 
contained  within  their  texture,  whether 
natural  or  artificial. 

When  calico,  muslin,  or  other  cotton 
fabrics  have  been  spun  and  woven,  they 
generally  pass  into  one  or  other  of  these 
establishments  before  being  brought  to 
market.  If  they  are  to  bo  sold  in  the 
white  state,  they  require  bleaching  •  if  in 
a  colored  state,  they  require  dyeing  ;  if  in 
a  decorated  or  ornamented  state,  they  re- 
quire printing ;  and  hence  it  arises  that 
there  are  in  one  establishment  or  congre- 
gated together,  oleach-worlcs,  dye-works, 
and  print-works.  As,  however,  a  well- 
printed  piece  of  cotton  requires  to  be 
bleached  and  dyed  as  well  as  printed, 
the  print-works  "have,  in  most  cases,  the 
means  for  carrying  on  the  bleaching  and 
dyeing  as  well  as  the  printing  processes ; 
and  there  are  thus  facilities  for  witness- 
ing all  three  operations  in  one  establish- 
ment. Most  of  these  works  are  situated 
in  the  valleys  (when  not  worked  by 
steam-power),  in  order  to  have  a  supply 
of  water  from  the  streams  which  flow 
through  them. 

Bleaching  is  now  a  very  different  pro- 
cess from  what  it  was  in  the  last  century. 
At  that  time  it  required  a  period  of 
several  months  to  bleach  a  piece  of  cloth, 
and  this,  too,  only  in  the  summer  time. 
In  some  cases  the  cloth  was  sent  in  the 
spring  of  the  year  to  Holland,  to  be 
bleached  on  the  level  grassy  plains  of 
that  country,  and  returned  in  the  au- 
tumn ;  while  in  other  cases,  when  bleach- 
ed in  the  English  fields,  there  was  so 
much  depredation  as  to  lead  to  an  unhap- 
py system  of  severe  laws  and  general 
distrust.  Chemists  were  thence  led  to 
inquire  whether  means  might  not  be 
adopted  more  expeditious  than  that  of 
exposure  to  the  open  air  of  a  bleach- 
ground.  Home,  Scheele,  Berthollet,  and 
Henry,  made  successive  steps  in  this 
direction,  and  paved  the  way  for  the  in- 
troduction of  the  use  of  bleaehing-poxvder, 
by  Mr.  Tennant,  about  the  year  1800. 
From  that  date  the  present  most  efficient 
system  of  bleaching  has  been  followed  in 
the  great  works  of  the  north,  modified 
occasionally  in  the  minor  details. 

Most  large  bleach-works  exhibit  a  con- 
siderable range  of  buildings,  comprising 
a  croft  or  bleach-house,  a  dye-house,  re- 
servoirs and  water-filters,  and  subsidiary 


42 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[blk 


buildings.  The  supply  of  water  required 
in  bleaehing  and  dyeing  is  enormous, 
and  extensive  arrangements  are  necessary 
for  the  filtering  of  the  water  before  using, 
since  the  success  of  the  process  very 
much  depends  on  the  purtiy  of  the  water. 

Matters  are  then  ready  for  the  bleach- 
ing process.  The  croft  (so  named  proba- 
bly because  it  renders  the  same  service 
as  the  croft  or  bleaching-ground  under 
the  old  system),  is  generally  a  large  stone- 
floored  building,  filled  with  coppers  and 
vessels  of  various  kinds,  abundantly  sup- 
plied with  water,  and  not  often  free  from 
clouds  of  steam.  Here  successive  wash- 
ings, boilings,  and  steepings  bring  the 
cotton  to  a  white  state.  In  the  first 
place  the  singed  cloth,  which  has  ac- 
quired a  kind  of  nankeen  colour,  is  fur- 
ther sewn  up,  until  five  hundred  pieces 
are  connected  together,  end  to  end ;  that 
is,  there  are  500  X  28  =  14,000  yards,  or 
eight  miles  of  cloth  in  one  continuous 
piece.  This  enormous  piece  passes  into 
a  wasking-en<fine,  to  cleanse  it  from  the 
"  dressing"  or  mucilage  which  the  weaver 
had  introduced  into  his  warp.  The  en- 
gine contains  an  abundant  and  constantly 
renewing:  supply  of  water ;  and  the  cloth 
is  wound  spirally  round  a  kind  of  beam 
above  it,  hanging  in  the  water  in  a  suc- 
cession of  bends  or  curvatures.  The 
cloth  travels  onwards,  and  in  so  doing 
passes  twenty  times  through  the  water 
beneath,  every  part  of  it  ascending  and 
descending  twenty  times  before  it  leaves 
the  machine.  About  two  hundred  and 
fifty  yards  are  thus  washed  per  minute  ; 
and  the  paste  which  is  washed  from  the 
cloth  is  carried  away  by  a  pipe. 

As  the  cloth  leaves  the  washing-ma- 
chine, it  is  taken  by  one  or  two  men  and 
folded  backward  and  forward  till  the 
whole  connected  piece  forms  a  cube  of 
five  or  six  feet.  From  this  heap  it  is 
again  removed  to  undergo  the  process  of 
"  liming."  The  cloth  passes  into  a  kind 
of  boiler  called  a  "  keir,"  where  it  is  ex- 
posed for  eight  or  ten  hours  to  the  action 
of  a  solution  of  lime,  40  lbs.  of  lime  being 
used  for  the  eight  miles  of  cloth.  In  this 
keir  or  vessel  the  hot  liquor  is  brought 
up  a  central  tube  in  such  a  manner,  that, 
being  echoed  or  reflected  from  a  concave 
surface  above,  it  falls  down  on  the  cloth 
in  a  profuse  shower,  thus  acting  equally 
on  the  whole  of  the  cloth.  The  cloth  is 
next  subjected  to  a  second  washing,  to  re- 
move the  lime  which  may  be  retained  by 
its  fibres.  Then  ensues  the  process  of 
"  grey  souring,"  in  which  the  cloth  passes 
through  a  machine  similar  to  the  wash- 


ing-machine, but  containing  very  dilute 
sulphuric  acid  instead  of  water ;  and  af- 
ter this  there  is  a  third  washing  in  the 
machine,  to  remove  all  the  adherent  acid. 
After  this  comes  the  "first  ashing." 
Twenty-four  miles  of  cloth  (the  real  ex- 
tent of  these  operations,  as  conducted  at 
the  present  day  in  large  establishments, 
will  be  better  appreciated  thus  than  by 
speaking  of  1500  pieces),  are  put  into  a 
keir,  or  cast-iron  boiler,  and  exposed  for 
sixteen  hours  to  the  action  of  a  boiling- 
hot  solution  of  soda :  this  constitutes  the 
"  ashing."  Then  for  a  fourth  time  the 
cloth  is  washed,  preparatory  to  the  pro- 
cess named  "  chemicking."  A  weak  so- 
lution of  bleaching-powder,  or  chloride  of 
lime,  is  put  into  a  machine  something 
like  the  washing-machine,  and  the  cloth 
is  passed  through  it.  After  lying  wet  in 
the  heap  for  six  or  eight  hours,  to  allow 
the  "chemick"  to  act  on  the  fibres,  the 
cloth  goes  through  the  process  of  "  se- 
cond souring"  in  weak  sulphuric  acid, 
somewhat  as  before.  It  is  then  washed 
for  a  fifth  time  in  the  machine,  to  which 
succeeds  the  "second  ashing;"  then  a 
sixth  washing,  then  a  "second  chemick- 
ing," then  a  "  third  souring,"  and  then  a 
seventh  washing.  It  will  thus  be  seen 
that  there  is  a  succession  of  processes 
following  in  a  certain  order;  the  three 
agents, — sulphuric  acid,  soda,  and  bleach- 
ing-powder,— being  separately  applied, 
each  more  than  once,  and  the  cloth  being 
washed  in  clean  water  after  every  such 
application.  So  powerful  is  the  bleach- 
ing-agent,  that  7  lbs.  of  chloride  of  lime 
are  said  to  suffice  for  the  bleaching  of 
500  pieces  of  cloth.  The  machines  here 
described  are  a  late  improvement:  for 
until  recently  the  cloth  was  dipped  in 
tanks  to  be  "soured" and  "chemicked," 
and  thence  hauled  up  by  poles. 

After  a  process  of  "  hot-watering"  and 
squeezing,  the  cloth  leaves  the  croft,  and 
passes  into  a  room  where  boys  and  girls 
rip  or  pick  the  pieces  asunder,  so  that 
each  piece  of  twenty-eight  yards  becomes 
again  separated  from  the  others.  Each 
piece  is  folded  into  a  flat  square  mass, 
and  men  beat  these  masses  against  the 
edge  of  a  stone  in  a  peculiar  manner,  for 
the  purpose  of  removing  creases  from  the 
cloth.  The  cloth  is  then  hung  up  on 
wooden  bars  in  a  drying-room,  which  is 
heated  to  a  high  temperature  by  steam- 
pipes  near  the  floor.  Finally,  the  bleached 
cloth,  which  now  presents  a  whiteness  of 
the  utmost  purity,  is  brought  into  the 
warehouse,  sorted,  and  tied  up  into  par- 
cels of  ten  pieces  each. 


BLO] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


43 


Such  is  a  brief  sketch  of  the  process  of 
bleaching  cotton ;  and  whether  we  notice 
it  in  connexion  with  dyeing  and  printing, 
or  take  the  instance  of  a  bleachery  inde- 
pendent of  them,  the  preceding  details 
will  equally  serve  to  convey  a  general 
idea  of  this  important  process. 

The  colour  of  manufactured  wool  de- 
pends partly  upon  its  own  oil,  and  partly 
upon  the  applications  made  to  it  in  the 
loom.  These  are  got  rid  of  in  the  fulling 
mill  by  the  joint  action  of  fullers'  earth 
and  soap ;  the  cloth  is  then  well  washed 
and  dried,  and  is  tolerably  white ;  if  the 
slight  yellow  tint  which  it  retains  is  ob- 
jectionable, it  is  prevented  bj  adding  a 
little  stone-blue  to  the  washing  water,  or 
by  exposure  to  the  fumes  of  burning  sul- 
phur ;  this  latter  method,  however,  give3 
it  a  harsh  feel,  and  if  afterwards  soaped, 
its  yellowishness  returns. 

TMie  colour  of  raw  silk  depends  upon  a 
natural  yellow  varnish,  which  is  got  rid 
of  by  boiling  it  in  white  soap  and  water, 
and  by  repeated  rincings.  Certain  arti 
"los  of  wove  cotton,  such  as  stockings, 
are  bleached  as  usual,  and  finished  by  the 
action  of  sulphurous  acid,  or  the  fumes 
of  burning  sulphur.  Straw  is  also  whiten- 
ed by  a  similar  operation;  and  hence 
bleached  straw  hats  are  apt  to  have  a  dis- 
agreeable sulphurous  smell. 

BLEACHING  POWDER.  Chloride 
of  lime,  made  by  exposing  slaked  lime  to 
the  action  of  chlorine.  The  best  samples 
do  not  contain  more  than  30  per  cent,  of 
chlorine;  it  varies  greatly  in  strength. 
Professor  Graham's  test  is  simple  in 
practice,  and  depends  on  the  effect  of  the 
chlorine  of  the  bleaching  powder  in  per- 
oxidizing  the  proto-salt  of  iron,  of  which 
two  equivalents  require  one  of  chlorine. 
The  chlorine  acts  by  decomposing  water, 
and  liberating  a  corresponding  quantity 
of  oxygen. 

BLENDE.     Native  sulphuret  of  zinc. 

BLOCK.  (Teutonic.)  In  architecture, 
a  large  unworked  mass  of  marble  or  other 
stone.  It  is  also  vulgarly  used  to  denote 
a  modillion  in  a  cornice. 

Block.  In  navigation,  the  case  that 
contains  the  wheel  or  sheeve  of  the  pulley 
(which  last  term  is  not  used  at  sea.)  Two 
or  more  blocks,  with  the  rope,  constitute 
a  tackle  (pronounced  tacle.)  Blocks  are 
also  the  pieces  of  wood  and  iron  on  which, 
piled  up,  the  ship's  keel  is  supported 
when  she  is  in  dock. 

BLOCK  TIN.  Tin  cast  into  blocks  or 
ingots.  It  is  generally  less  pure  than 
grain  tin. 

BLOOD.    The  fluid  which  circulates 


in  the  heart  and  blood-vessels.  When 
viewed  under  the  microscope  it  appears 
to  consist  of  very  minute  red  globules,  or 
spheroids,  floating  in  a  colourless  fluid. 
The  average  quantity  in  an  adult  man  is 
estimated  at  about  28  lbs. ;  it  is  of  two 
distinct  colours  in  the  arterial  and  venous 
systems, — florid  red  approaching  to  scar- 
let in  the  former,  and  dark  crimson  in 
the  latter.  Its  specific  gravity  is  between 
1-050  and  1-070.  When  drawn  from  its 
vessels  it  gelatinizes  or  coagulates  in  the 
course  of  a  few  minutes  of  common  tem- 
perature, and  soon  separates  spontane- 
ously into  serum  and  coagulum.  The 
serum  is  a  yellowish  soapy-feeling  fluid, 
of  the  specific  gravity  of  about  1*080.  It 
exhibits  a  slight  alkaline  reaction  upon 
test  papers ;  when  heated  it  becomes 
opaque,  and  at  156°  it  coagrjates.  It  is 
also  coagulated  by  alcohol,  i*nd  by  most 
of  the  acids  ;  acetic  acid  ar.d  ether  do  not 
coagulate  it ;  solutions  oi  corrosive  sub- 
limate, of  subacetate  of  lead,  and  of  chlo- 
ride platinum,  occasion  precipitates  in  it, 
even  when  considerably  diluted  with  wa- 
ter. These  properties  of  serum  are  de- 
pendent upon  the  presence  of  a  peculiar 
proximate  animal  principle  called  albu- 
men :  the  same  substance,  and  with  very 
nearly  the  same  properties,  constitutes 
the  white  of  egg,  the  coagulability  of 
which  by  heat  is  well  known.  Besides 
the  above  there  is  another  most  delicate 
test  of  albumen  in  solution,  which  con- 
sists in  adding  to  the  liquid  suspected  to 
contain  it  a  little  strong  acetic  acid,  and 
afterwards  a  few  drops  of  ferrocyanate  of 
potash.  If  albumen  be  present,  a  white 
cloud  is  produced.  This  is  even  a  more 
accurate  test  than  corrosive  sublimate. 
White  of  egg  is  coagulated  by  ether, 
while  serum  is  not.  According  to  Mar- 
cet,  1000  parts  of  serum  of  human  blood 
are  composed  of  water  900,  albumen,  86-8, 
muriates  of  potassa  and  soda  6-6,  muco- 
extractive  4,  carbonate  of  soda  1-65,  sul- 
phate of  potassa  0*35,  earth  phosphates 
0-60. 

The  coagulum  of  the  blood  is  or  a  more 
or  less  firm  texture,  and  has  a  greater 
specific  gravity  than  the  serum.  It  con- 
tains the  coloring  particles  of  the  blood  ; 
and  when  carefully  washed,  these  are 
carried  out  of  it,  and  a  tenacious  whitish 
matter  remains,  which  has  been  termed 
fibrine,  but  which,  in  all  essential  points, 
has  the  properties  of  coagulated  albumen. 

The  coloring  matter  of  the  blood,  hanma- 
tosine,  may  be  obtained  by  evaporating 
its  aqueous  solution  at  a  temperature  be- 
low 100° ;  it  then  appears  almost  black, 


44 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[blo 


but  resumes  its  red  color  when  dissolved 
in  water.  It  is  soluble  in  acids  and  in 
alkalies.  These  solutions  are  dark-color- 
ed; but  when  mixed,  so  as  to  become 
neutral,  the  hsematosine  falls  of  a  bright 
red  color.  Accordingly,  when  the  clot  of 
blood  is  put  into  acids  it  becomes  brown 
or  blackish,  and  is  very  similarly  disco- 
lored by  alkalies  ;  but  most  neutral  salts 
render  it  florid. 

The  chief  use  of  blood  is  as  a  manure 
made  into  a  compost  of  50  gallons  of 
blood  with  a  quarter  of  peat-ashes  and 
charcoal  powder ;  on  light  soils,  48  bush- 
els have  been  laid  on  each  acre,  or  half  a 
hundred  weight  with  twelve  tons  of  farm 
dung.  It  is  now  rarely  used  in  sugar  re- 
fining. It  is  used  to  make  animai  char- 
coal in  Prussian  blue  works,  and  also  in 
gome  Turkey-red  dye  works. 

BLOW-PIPE.  An  instrument  for  di- 
recting a  small  jet  of  air  laterally  into  the 
flame  of  a  candle  or  lamp,  so  that  a  por- 
tion of  the  flame  is  formed  into  a  long 
slender  cone  in  the  direction  of  the  jet, 
the  heat  of  which  increases  towards  the 
end  of  the  cone,  and  at  the  point  is  most 
intense.  A  common  flame  thue  becomes 
a  small  furnace  :  so  that  a  small  piece  of 
any  substance  may  be  subjected  to  a  high 
temperature  almost  instantly,  and  fused. 
It  is  much  used  in  soldering  by  the  jewel- 
er, goldsmith,  and  workers  in  fine  me- 
tal ;  by  the  glass-blower  and  the  enamel- 
ler.  In  the  bands  of  the  analytic  chemist 
it  is  an  invaluable  instrument.  The 
mouth  blow-pipe  is  a  small  tube  tapering 
gradually  to  a  fine  point,  having  a  small 
bulb  intermediate,  not  far  from  the  fine 
jet.  The  latter  blow-pipe  is  blown  with 
a  bellows  instead  of  the  mouth. 

BLUBBER.  The  cellular  membrane 
in  which  the  oil  or  fat  of  the  whale  is  in- 
cluded. Its  thickness  varies  from  eight 
to  twenty  inches,  and  yields  as  much  fre- 
quently as  100  tons  of  oil  from  a  full- 
frown  whale.  It  is  generally  brought 
ome  from  the  fishing-ground' packed' in 
casks.  The  oil  is  drained  out  of  the 
blubber  by  placing  the  latter  cut  up  on 
racks,  through  which  the  oil  drips  down 
into  casks.  It  is  then  heated  up  to  225°, 
to  deprive  it  of  its  rancid  smell,  and  also 
to  make  the  grosser  parts  settle.  The  oil 
is  then  pumped  over  with  cool  water,  left 
to  cool,  and  finally  stored  in  casks. 

BO  ATS— Like-Boats.  Since  the  exten- 
sive application  of  India-rubber  and  gut- 
ta  percha  to  useful  purposes,  these  sub- 
stances have  been  employed  -tfith  much 
success  in  the  constitution  of  life-boats 
and  buoys.     {See  Life  Boat.) 


BOMBAZINE.  A  fabric,  the  warp  of 
which  is  silk  and  the  weft  worsted.  It 
It  is  chiefly  made  in  black,  and  is  an  ar- 
ticle of  mourning  for  female  dress. 

BOLE.  An  earthy  mineral ;  a  hydrated 
silicate  of  alumina,  resembling  soapstone. 
When  put  in  water  it  absorbs  it,  and  falls 
to  pieces.  Armenian  bole  is  used  as  an 
ingredient  of  tooth-powders,  and  it  also 
enters  into  the  composition  of  common 
red  paints. 

BONE.  An  important  organ  in  the 
higher  orders  of  animals,  forming  the 
solid  support  of  their  fabric,  and  pro- 
tecting the  vital  organs,  such  as  the  brain 
and  the  heart  and  lungs,  from  external 
pressure  and  injury.  In  the  human  skele- 
ton there  are  commonly  enumerated  260 
distinct  bones.  They,  however,  admit  of 
classification  under  three  heads  :  namely, 
long  or  cylindrical  bones,  such  as  those  of 
the  extremities ;  broad  and  fiat  bones, 
such  as  those  of  the  skull ;  and  short, 
square,  irregular,  or  solid  bjnes,  such  as 
the  vertebra?,  and  those  ol  the  wrist  and 
instep,  and  the  patella  o»  knee-pan :  the 
first  bones  are  generally  filled  with  mar- 
row, and  are  admirable  specimens  of 
strength  of  structure  with  the  least  possi- 
ble weight.  The  bones  are  covered  by  a 
membrane  called  periosteum,  by  which 
the  ramifications  of  blood-vessels  and 
nerves  pass  into  the  bone.  In  the  growth 
of  a  bone,  the  gelatinous  or  cartilaginous 
portion,  as  it  has  been  sometimes  called, 
is  first  formed,  and  the  earthy  or  indur- 
ating part  is  afterwards  deposited.  We 
are  indebted  to  Mr.  Hatchett  for  our 
principal  information  respecting  the 
proximate  chemical  components  ot  bone. 
The  soft  parts  consist  ot  gelatine  and  al- 
bumen, and  the  hard  portion  is  composed 
of  phosphate  of  lime  and  carbonate  of 
lime,  with  small  quantities  of  other  salts. 
The  animal  matter  of  bones  amounts  on 
an  average  to  about  half  their  weight,  or 
when  dried,  to  between  30  and  40  per 
cent.;  so  that  they  contain  a  large  relative 
proportion  of  nutritive  matter.  The 
bones,  including  their  animal  matter,  are 
the  most  durable  parts  of  the  animal  fa- 
bric :  hence  the  proposal  of  storing  them 
up  as  occasional  sources  of  nutriment; 
for  not  only  is  the  cartilaginous  portion 
unimpaired,  in  bones  which  have  been 
kept  dry  for  many  years,  but  it  has  even 
been  found  perfect  m  bones  of  apparently 
antediluvian  origin.  The  best  mode  of 
extracting  the  nutritious  part  of  bone  for 
human  food  consists  in  grinding  it  fine, 
and  subjecting  it  with  water  to  a  heat  of 
about  220°  iii  a  digester ;  or  the  earthy 


BOO 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


45 


part  may  be  removed  by  dilute  muriatic 
acid.  When  dogs  and  some  other  ani- 
mals devour  bones,  the  nutritive  part  is 
abstracted  by  their  gastric  juice,  and  the 
earthy  part  is  voided  in  their  excrement, 
forming  what  was  formerly  called  album 
grcecum. 

When  bones  are  submitted  to  destruc- 
tive distillation,  the  gelatine  and  albumen 
which  they  contain  is  abundantly  produc- 
tive of  ammonia;  hence  a  copious  source 
of  that  alkali  and  its  compounds ;  the 
residue  is  a  mixture  of  the  earthy  part  of 
the  bone  with  charcoal,  commonly  termed 
ivory  or  bone  black. 

BONE  DUST,  or  ground  bones,  has 
recently  been  used  with  the  best  effect  as 
a  manure.  It  is  usually  applied  to  light 
or  turnip  soils,  which  it  has  rendered  in 
no  ordinary  degree  productive.  It  is  an 
excellent  addition  to  grass  land,  and  its 
application  generally  is  too  much  neglect- 
ed in  this  country,  where  a  large  exporta- 
tion of  bones  to  England  occurs  yearly 
from  Boston.  The  agriculture  of  the  At- 
lantic States  requires  the  use  of  bones  as 
much  as  that  of  England  does. 

BONE  EARTH.  The  residue  of  bones 
which  have  been  calcined  so  as  to  destroy 
the  animal  matter  and  carbon,  and  become 
converted  into  a  white  porous  and  friable 
substance,  composed  chiefly  of  phosphate 
of  lime.  According  to  Berzelius,  100 
parts  of  human  bones  are  composed  of 
51-04  phosphate  of  lime,  11*30  carbonate 
of  lime,  2  fluoride  of  calcium,  1-20  soda 
and  chloride  of  sodium,  1-16  phosphate 
of  magnesia,  and  33-30  animal  matter. 
Albumen,  gelatine,  and  fat  constitute  the 
animal  part  of  bone,  the  greater  part  of 
which  remains  in  the  form  of  a  tough 
cartilage  when  bones  are  steeped  in  dilute 
muriatic  acid. 

In  the  arts,  bones  are  employed  by  cut- 
lers, turners,  manufacturers  of  animal 
charcoal,  and  by  assayers  for  making  cu- 
pels. 

BONE  BLACK  is  the  carbonaceous 
substance  which  remains  after  the  calcin- 
ation of  bones  in  close  vessels.  This 
kind  of  charcoal  has  two  applications :  to 
deprive  syrups  and  other  solutions  of 
their  coloring  matters,  and  to  furnish  a 
black  pigment.  (&*>  Ivoky  Black.)  In  the 
calcination  bones  lose  half  their  weight, 
and  the  resulting  charcoal  is  more  valuable 
when  the  bones  have  been  steamed  pre- 
viously, so  as  to  remove  fat  and  mem- 
brane. It  is  after  being  calcined,  ground 
in  a  mill,  and  sifted.  In  the  calcina- 
tion volatile  inflammable  gases  and  oils 
are  given  off, — the  latter  are  used  to  fon 


lamp  black ;  at  the  close  of  the  process 
muriate  of  ammonia  and  sulphate  of  soda, 
— the  latter  is  washed  out,  and  the  for- 
mer, which  is  a  valuable  salt,  is  sublimed. 

Bone  black  has  a  remarkable  attraction 
for  organic  coloring  matter;  this  varies 
with  the  heat  at  which  it  was  made  :  if 
too  high,  it  becomes  glazed ;  if  too  low 
a  heat  was  employed,  the  albumen  of  the 
bone  is  not  destroyed.  After  this  char- 
coal has  been  used,  it  may  be  renovated 
by  heating  it  to  redness  in  a  furnace. 

BOOKBINDING.  There  are  several 
and  distinct  branches  of  this  business, — 
plain  and  ornamental  binding, — law  bind- 
ing,— blank  book  and  ledger  binding ;  the 
latter  is  a  department  in  itself,  and  usually 
conducted  by  stationers. 

The  various  sizes  of  a  book  are  desig- 
nated by  the  number  of  leaves  in  which 
the  sheet  is  folded :  thus  folio  is  2  leaves ; 
quarto,  4  leaves ;  octavo,  8  leaves ;  duo- 
decimo, 12  to  a  sheet;  and  so  on  to  the 
smallest  sizes  of  24mo  and  32mo.  After 
the  sheets  of  a  book  have  been  folded, 
they  are  collated  by  the  wumeral  or 
letter  placed  at  the  foot  of  the  first 
page  in  the  first  sheet,  in  order  to 
ascertain  that  the  work  is  perfect.  The 
next  process  is  that  of  pressing:  this 
is  done  in  a  hydraulic  press.  The  back 
of  the  sheets  is  then  sawed  by  machine, 
after  which  the  sewing  process  com- 
mences. This  last  is  a  quick  operation, 
as  a  girl  can  sew  three  thousand  sheets 
a  day.  The  middle  of  the  sheets  are 
stitched  with  thread  to  the  upright  cords 
fastened  on  the  press;  as  soon  as  one 
sheet  is  fastened  to  all  the  strings,  ano- 
ther is  laid  down  on  it,  and  fastened  in 
a  similar  manner.  India-rubber  binding 
supersedes  the  necessity  of  sewing,  bind- 
ing every  leaf  as  securely,  and  giving 
greater  flexibility. 

When  the  sewing  is  finished  the  strings 
are  cut,  leaving  an  inch  or  so  hanging, 
which  are  used  to  fasten  the  book  to  its 
case.  The  backs  of  the  sheets  are  now 
all  glued  to  increase  the  connection. 

By  hammering  on  wooden  blocks,  or 
better  still,  by  passing  the  sheets  be- 
tween rollers,  the  back  is  rounded  and 
the  front  hollowed  out,  and  a  grooved 
hollow  made,  into  which  the  millboard  is 
fitted,  the  covers  being  fastened  by  the 
strings  through  the  boards.  The  book  is 
next  placed  between  boards  and  screwed 
up  in  a  press,  with  one  of  its  ends  pro- 
jecting. The  ends  of  the  leaves  are  now 
cut  off  fair'by  a  plough,  the  cutting  edge 
of  which,  in  its  action,  is  midway  between 
a  knife  and  a  plane-iron.    When  books 


46 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


are  bound  in  leather,  the  sides  of  the 
covers  are  previously  stamped  with  a  de- 
vice, or  embossed  as  it  is  termed.  The 
embossing  machine  sometimes  exerts  a 
pressure  of  50  tons.  The  devices  on  the 
back,  edges,  and  margin,  are  placed  on 
by  hand  \vith  a  revolving  wheel,  which 
has  on  its  edge  the  device  cut  out,  and 
which  leaves  its  impression  when  the 
wheel  is  rolled  along. 

Gutta  percha  has  lately  been  introduced 
into  binding,  to  imitate  the  antique  old 
oak  binding. 

When  books  are  to  be  gilt,  the  edges 
are  scraped  and  burnished  with  the  agate 
burnisher,  then  colored  over  with  red 
bole  or  chalk,  ground  in  soap,  rubbed  in 
fine  paper,  and  aerain  well  burnished; 
this  brightens  up  the  gilding.  The  gold 
leaf  is  then  cut  into  slips,  and  laid  on. 
Gilding  on  marbled  edges  has  a  very 
beautiful  effect,  as  the  marbling  is  per- 
ceived through  the  gold. 

Several  of  the  book  binderies  in  New- 
York,  Philadelphia,  and  Boston,  employ 
from  fifty  to  one  hundred  persous,  in- 
cluding females  who  stitch  and  fold. 

BORACIC  ACID.    (See  Boron.) 

BORAX.  This  salt  is  found  native  in 
some  of  the  lakes  of  Thibet  and  Persia, 
and  is  imported  from  India  under  the 
name  of  tlncal,  which,  after  purification, 
forms  the  refined  borax  of  commerce.  Of 
late  years  borax  has  been  obtained  by 
combining  native  boracic  acid  with  soda. 
Borax  forms  hexahedral  prisms,  slightly 
efflorescent,  and  requiring  20  of  cold  and 
6  of  boiling  water  for  solution.  When 
heated,  water  of  crystallization  is  driven 
off,  and  the  residuary  salt  fuses  into  what 
is  called  glass  of  borax. 

Crystallized  borax  consists  of  68  boracic 
acid  +  32  soda  +  90  water.  It  has  upon 
some  tests  an  alkaline  reaction,  and  lias 
hence  been  called  svb-borate  of  soda.  Bor- 
ax is  chiefly  used  by  workers  in  metals  as 
a  flux :  it  is  also  employed  in  medicine. 

Dry  borax  acts  on  metallic  oxides  at  a 
high  temperature,  melting  and  vitrifying 
them  into  beautiful  colored  glasses",  on 
which  account  it  is  a  most  useful  reagent 
with  the  blow-pipe.  It  tinges  oxide  of 
chrome,  emerald  green ;  oxide  of  cobalt, 
intense  blue ;  oxide  of  copper,  pale  green ; 
oxide  of  tin,  opal ;  oxide  of  iron,  bottle- 
green  ;  oxide  manganese,  violet.  In  the 
fusion  of  metals  it  protects  the  surface 
from  oxidizement,  and  dissolves  any  ox- 
ides off  the  surface :  hence  it  is  an  excel- 
lent flux  in  the  hands  of  the  goldsmith,  in 
soldering  precious  metals,  and  to  the 
brazier,  in  soldering  copper  and  iron. 


When  mixed  with  shell-lac,  in  the  ratio 
of  1  to  5,  it  renders  the  lac  soluble  in  wa- 
ter, and  forms  with  it  a  species  of  varnish. 

BORON.  The  base  of  boracic  acid, 
discovered  by  Davy  in  1807.  It  may  be 
procured  by  heating  dry  boracic  acid  with 
potassium.  It  is  a  dark  olive-colored 
substance,  a  nonconductor  of  electricity, 
insoluble  in  water,  infusable,  and  of  a 
specific  gravity  =  2,  Heated  to  redness 
it  burns  into  boracic  acid,  which  consists 
of  20  boron  +  48  oxygen. 

Boracic  acid  is  found  in  the  hot  springs, 
and  amongst  the  volcanic  products  of  the 
Lipari  islands,  and  in  the  waters  of  Sasso 
in  the  Florentine  territory ;  it  also  occurs 
in  some  minerals.  It  may  be  obtained 
by  adding  excess  of  sulphuric  acid  to  a 
strong  solution  of  borax.  Its  specific  gra- 
vity is  1*48.  In  its  usual  state  of  scaly 
crystals  it  is  a  hydrate,  composed  of  68 
dry  acid  +  27  water.  In  this  state  it  re- 
quires about  30  parts  of  cold  and  3  of 
boiling  water  for  its  solution.  It  dis- 
solves in  alcohol,  and  the  solution  burns 
with  a  characteristic  green  flame.  It 
reddens  litmus  ;  but  renders  turmeric 
brown,  like  an  alkali.  When  its  water 
is  driven  off  by  fusing  it  at  a  high  heat, 
the  anhydrous  acid  concretes  into  a  glassy 
substance  of  the  specific  gravity  of  1*8. 
It  is  a  useful  flux,  and  was  formerly  used 
in  medicine  under  the  name  of  Homberg's 
sedative  salt. 

The  boracic^  acid  lagoons  of  Tuscany 
are  an  interesting  instance  of  the  conver- 
sion of  a  natural  phenomenon,  which 
seemed  only  a  subject  of  wonder,  into 
a  productive  manufacture.  These  lagoons 
are  depressions  or  mud  holes  in  the  soil, 
from  which  issue  hot  vapors  highly  im- 
pregnated with  boracic  acid,  which  were 
formerly  regarded  with  terror  by  the 
inhabitants  of  their  vicinity,  and  they 
sought  by  public  prayers  a  deliverance 
from  this  scourge.  In  1818,  Mr.  Lan- 
derel  conceived  the  idea  of  rendering 
these  vapors  a  source  of  profit.  The  la- 
goons being  situated  upon  the  declivity 
of  a  mountain,  they  were  surrounded  by 
a  basin  of  mason  work,  and  water  from 
the  mountain  stream  conducted  into 
them,  so  as  to  form  a  series  of  artificial 
lakes  at  different  levels.  The  water  is 
let  into  the  upper  basin,  where  it  remains 
some  twenty  or  thirty  hours  and  becomes 
impregnated  by  the  acid  vapors ;  at  the 
end  of  this  time  the  water  is  drawn  off 
into  the  second  basin,  when  it  receives  a 
further  pregnation ;  and  so  on  successive- 
ly through  six  or  eight,  until  it  reaches 
the  evaporating  reservoirs.     These  are 


bra] 


CYCLOPEDIA    OF   THE   USEFUL    ARTS 


41 


of  lead,  and  the  heat  for  carrying  on  the 
evaporation  is  obtained  from  the  vapors 
themselves,  which  are  brought  in  pipes 
below  the  boilers.  All  the  means  of  ma- 
nufacture are  furnished  by  the  locality 
itself.  The  annual  product  of  these  la- 
goons is  two  and  a  half  millions  of  pounds. 
The  boracic  acid  is  converted  into  borax 
bv  combining  with  soda. 
'BOTTLE.    (See  Glass). 

BK  AN.  The  husk  of  wheat  which  im- 
mediately covers  the  grain,  and  which 
remains  in  the  bolting  machine.  It  is 
gently  laxative ;  an  infusion  of  it,  under 
the  name  of  bran  tea,  is  frequently  used 
as  a  domestic  remedy  for  coughs  and 
hoarseness.  Calico  prmters  employ  bran 
and  warm  water  with  great  success  to  re- 
move coloring  matter  from  those  parts  of 
their  goods  which  are  not  mordanted. 
This  appears  to  be  due  to  the  quantity  of 
earthy  phosphates  which  the  bran  con- 
tains. 

BRANDY.  A  spirituous  product  ob- 
tained by  distilling  wine  :  the  quality  va- 
ries with  the  wine  employed.  When 
pure  it  is  perfectly  colorless,  and  only  ac- 

Suires  a  pale-brown  or  yellow  tint  from 
le  cask.  The  deep  color  of  common 
brandy,  intended  to  imitate  that  which  it 
acquires  from  great  age  in  the  cask,  is 
generally  given  by  the  addition  of  burn- 
ed sugar.  The  average  proportion  of  al- 
cohol in  brandy  varies  from  48  to  54  per 
cent.  The  best  brandy  is  made  in  France, 
the  preference  being  generally  given  to 
that  shipped  from  Cognac.  (See  Distil- 
lation). 

BRASS.  An  alloy  of  copper  and  zinc : 
to  make  brass,  the  English  method  is  by 
melting  together  copper  in  round  masses, 
or  in  bars,  with  calamine,  which  is  a  na- 
tive oxyde  or  ore  of  zinc,  and  a  native 
carburet  of  zinc  combined  with  oxyde  of 
iron,  which  make  it  of  reddish  color,  and 
it  usually  contains  more  or  less  lead. 
The  calamine  is  powdered  and  separated 
by  washing,  then  heated  on  the  hearth 
of  a  reverberatory  furnace,  which  expels 
nie  volatile  matter,  usually  water  and 
carbonic  acid.  The  remainder  is  oxyde  of 
zinc,  and  a  small  portion  of  carbon,  which 
the  heat  cannot  wholly  remove,  and  some 
earthy  substances,  'the  proportions  are 
nearly  equal  weights  of  copper  and  cala- 
mine and  one-tenth  of  their  weight  of 
pulverized  charcoal,  which  are  together 
put  into  a  crucible  capable  of  containing 
100  pounds  of  brass  when  completed, 
but  when  charged  holding:  663,  calamine 
93,  and  charcoal  13,  which  is  covered 
with  clay,  sand,  &c,  to  keep  it  free  from 


the  air.  The  fire  is  continued  from 
twelve  to  twenty  hours,  when  the  refuse 
is  poured  oif,  the  metal  cast  into  ingots, 
then  usually  remelted  and  cast,  to  render 
it  better  and  finer,  when  it  is  rolled, 
drawn,  or  made  into  castings  for  use. 

Brass  is  often  made  by  melting  toge- 
ther small  pieces  of  cast  copper  and  zinc, 
which  is  made  into  ingots,  then  rolled 
into  sheets  slitted  and  drawn  into  wire. 
For  knife  scales,  sheet  brass  is  used 
which  is  not  annealed,  but  stiff  and  hard. 
Corinthian  brass,  famous  in  antiquity, 
was  an  alloy  of  gold,  silver,  and  copper. 
Lucius  Numminus,  146  years  before 
Christ,  captured  and  burned  the  city  of 
Corinth ;  and  the  violence  of  the  confla- 
gration formed,  from  the  abundance  of 
metals  in  its  course,  a  solid  sea  of  this 
alloy  in  the  streets  and  low  places.  Ger- 
man chemists  make  copper  of  a  gold  co- 
lor, by  exposing  it  to  the  fumes  of  zinc. 
The  comparative  stiffness  of  this  alloy 
permits  it  to  be  cut  by  saws  and  files, 
turned  and  worked  much  easier  than  iron. 
The  metal  anciently  called  brass,  is  the 
copper  of  modern  times  ;  and  the  Colos- 
sus at  Rhodes,  and  other  so-called  brazen 
fabrics,  were  formed  entirely  of  the  last 
named  metal. 

Brass-making  was  introduced  into  Eng- 
land in  1694,  where  it  proved  a  failure  to 
its  first  manufacturers,  but  it  is  now  a 
great  business  in  that  country.  Brass 
must  be  annealed  after  it  is  cast  into 
moulds,  or  it  will  be  so  brittle  that  it 
cannot  be  drawn.  Brass  is  lighter  than 
pure  copper,  but  it  is  harder.  It  is  only 
malleable  while  cold.  If  brass  is  heatea 
beyond  a  cherry  red,  the  zinc  separates 
from  the  copper  in  the  form  of  gas. 
There  are  a  great  variety  of  brass  alloys. 
Four  parts  of  copper  and  two  of  zinc, 
makes  a  beautiful  brass.  The  copper 
must  be  first  melted  then  the  zinc  is 
introduced,  and  as  soon  as  it  is  melted  it 
must  be  stirred  then  run  into  the  mould. 
The  reason  for  doing  this  is,  that  zinc  is 
volatilized  at  the  heat  of  fluid  copper, 
therefore,  if  the  zinc  and  copper  were  in- 
troduced together,  before  the  copper  was 
all  melted  a  great  portion  of  the  zinc 
would  have  departed  in  the  state  of  vapor. 

The  usual  proportion  of  metals  in  yel- 
low brass,  is  30  of  zinc  and  70  of  copper. 

Tomback  or  red  brass,  is  an  alloy  of 
copper  and  zinc  containing  not  more  than 
20  per  cent,  of  the  latter. 

Pinchbeck,  is  made  of  2  parts  copper 
and  1  of  yellow  brass. 

Prince's  Metal,  3  parts  copper  and  1 
of  zinc. 


48 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


I' 


Mannheim  gold,  28  copper,  12  yellow 
brass,  and  3  tin. 

Cast  white  metal-buttons,  are  made  of 
an  alloy  of  32  parts  brass  (yellow),  4  parts 
of  zinc,  and  2  of  tin. 

The  French  state  that  brass  containing 
two  per  cent,  of  lead  works  more  freely 
in  the  turning-lathe,  but  does  not  ham- 
mer so  well  as  the  ordinary  brass. 

BRASS  FOIL.  Dutch-leaf:  it  is  made 
from  very  thin  sheet  brass,  beat  out 
under  a  hammer  worked  by  water  power 
which  gives  3  or  400  strokes  per  minute : 
from  40  to  80  leaves  being  laid  over  each 
other.  By  this  treatment  it  acquires  its 
characteristic  solidity  and  lustre. 

BRAZIL  WOOD.  A  valuable  wood, 
imported  from  South  America  and  the 
West  Indies,  where  it  is  produced  by 
certain  species  of  Ccesalpima,  especially 
G.  echinata  and  Braziliensis  /  large  trees 
with  repeatedly  pinnated  leaves,  showy 
yellow  flowers,  and  long  richly  colored, 
stamens.  It  is  used  for  the  preparation 
of  a  red  dye,  but  the  consumption  of  it 
in  this  country  is  inconsiderable.  The 
coloring  matter  is  easily  affected  by  acids, 
producing  an  orange  or  yellow  color 
which  is  durable :  with  alkalies,  a  violet 
and  purple  color  is  produced — these  are 
fleeting.  The  color  given  to  silks,  known 
as  false  crimson,  is  by  means  of  Brazil 
wood.  The  silk  is  boiled  with  20  parts 
of  soap,  rinsed  and  passed  through  a 
bath  charged  with  this  wood.  Stronger 
colors  are  gained  by  giving  a  ground  of 
annotto  to  the  silk,  or  by  adding  log- 
wood to  the  bath. 

Nicaragua  and  peach  wood,  are  varie- 
ties of  the  Cfflsalpkna,  and  produce  dyes. 

The  coloring  .substances  belonging  to 
Brazil,  are  called  by  chemists  braziUne 
and  brazileine ;  the  first  being  the  color- 
ing matter  of  the  wood,  and  the  second 
a  colorless  substance  which  appears  to 
pass  into  the  proper  coloring  matter  by 
oxidation. 

BREAD.  (Ger.  brod.)  This  impor- 
tant article  of  food  is  made  of  the  flour 
of  different  grains  ;  but  it  is  only  those 
which  contain  gluten  that  admit  of  con- 
version into  a  light  or  porous  and  spongy 
bread,  of  which  wheaten  bread  furnishes 
the  best  example.  When  flour  is  made 
into  a  tough  paste  or  dough  by  the  ad- 
dition of  a  little  water,  rolled  out  into 
thin  cakes,  and  more  or  less  baked,  it 
forms  biscuit.  For  the  formation  of 
bread  a  certain  degree  of  fermentation, 
not  unlike  vinous  fermentation,  is  requi- 
site, care  being  taken  to  avoid  acetous 
fermentation,  which  renders  the  bread 


sour,  and  to  most  persons  disagreeable. 
If  dough  be  left  to  itself  in  a  moderately 
warm  place  (between  80°  and  120°),  a 
degree  of  fermentation  comes  on,  which, 
however,  is  sluggish,  or,  if  rapid,  ace- 
tous /  so  that  to  effect  that  kind  of  fer- 
mentation requisite  for  the  production  of 
the  best  bread,  &  ferment  is  added,  which 
is  either  leaven  or  dough  which  is  already 
in  a  fermenting  state,  and  which  tends 
to  accelerate  the  process  in  the  mass  to 
which  it  is  added  ;  or  yeast,  the  peculiar 
matter  which  collects  in  the  torm  of 
scum  upon  beer  in  the  act  of  fermenta- 
tion. Of  these  ferments  leaven  is  slow 
and  uncertain  in  its  effect,  and  gives  a 
sour  and  often  slightly  putrid  flavor. 
Yeast  is  more  effective ;  and  when  clean 
and  good,  it  rapidly  induces  panary  fer- 
mentation ;  but  it  is  often  bitter,  and 
sometimes  has  a  peculiarly  disagreeable 
smell  and  taste. 

All,  then,  that  is  essential  to  make  a 
loaf  of  bread  is  dough  to  which  a  certain 
quantity  of  yeast  has  been  added.  This 
mixture  is  put  into  any  convenient 
mould  or  form,  or  merely  shaped  into 
one  mass  ;  and  after  having  been  kept 
for  a  short  time  in  rather  a  warm  place, 
so  that  fermentation  may  have  begun,  it 
is  subjected  to  the  process  of  baking  in  a 
proper  oven.  Carbonic  acid  is  generated  ; 
and  the  viscidity  or  texture  of  the  dough 
preventing  the  immediate  escape  of  that 
gas,  the  whole  mass  is  puffed  up  by  it, 
and  a  light  porous  bread  is  the  result. 
Along  with  the  carbonic  acid  traces  of 
alcohol  are  at  the  same  time  produced, 
but  so  insignificant  and  impure  as  not  to 
be  worth  notice ;  hence  the  attempts 
which  have  been  made  to  collect  it  upon 
the  large  scale  have  entirely  failed  in  an 
economical  point  of  view.  Other  flour 
besides  that  of  wheat  will,  under  similar 
circumstances,  undergo  panary  fermen- 
tation ;  but  the  result  is  a  heavy,  un- 
palatable, and  often  indigestible  bread ; 
so  that  the  addition  of  a  certain  quantity 
of  wheat  flour  is  almost  always  had  re- 
course to.  It  is  the  gluten  in  wheat 
which  thus  peculiarly  fits  it  for  the  man- 
ufacture of  bread,  chiefly  in  consequence 
of  the  tough  and  elastic  viscidity  which 
it  confers  upon  the  dough. 

It  is  well  Known  that  home-made  bread 
and  baker's  bread  are  two  very  different 
things  :  the  former  is  usually  sweeter, 
lighter,  and  more  retentive  of  moisture  ; 
the  latter,  if  eaten  soon  after  it  has 
cooled,  is  pleasant  and  spongy ;  but  if 
kept  for  more  than  two  or  three  days,  it 
becomes  harsh   and  unpalatable.      The 


•] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


49 


cause  of  this  difference  may  perhaps  be 
obvious  from  the  following  details  of  the 
operations  of  the  wholesale  baker. 

In  making  his  dough  he  takes  the 
water,  or  part  of  it,  which  he  intends  to 
use,  and  having  slightly  warmed  it,  dis- 
solves in  it  a  certain  portion  of  salt ;  then 
he  adds  the  yeast,  and  then  a  certain 
quantity  of  flour.  This  mixture  is  set 
aside  in  a  warm  place,  where  it  soon  be- 
gins to  ferment.  This  process  is  called 
setting  the  sponge  ;  and  according  to  the 
relation  which  the  water  in  it  bears  to 
the  whole  quantity  to  be  used  in  the 
dough,  it  is  called  whole,  half,  or  quar- 
tern sponge.  The  evolution  of  carbonic 
acid  causes  the  sponge  to  heave  and 
swell ;  and  when  the  surface  bursts  it 
subsides,  and  then  swells  again,  and  so 
on ;  but  the  baker  is  careful  to  use  it 
before  this  fermentation  has  communi- 
cated sourness  to  the  mass.  He  then 
adds  to  the  sponge  the  remaining  quan- 
tity of  flour,  water,  and  salt,  which  may 
be  required  to  form  dough  of  proper 
quality  and  consistence,  and  incorporates 
the  whole  by  long  and  laborious  knead- 
ings  till  the  entire  mass  acquires  unifor- 
mity, and  is  so  tough  and  elastic  as  to 
bear  the  pressure  of  the  hand  without 
adhering  to  it.  It  is  then  left  for  a  few 
hours,  during  which  fermentation  goes 
on ;  and  the  inflated  mass  is  again 
kneaded,  so  as  to  break  down  any  lumps 
or  portions  which  had  accidentally  escap- 
ed diffusion  in  the  first  operation,  and  to 
confer  perfect  uniformity  on  the  whole. 
The  dough  is  then  weighed  out  into  loaves, 
which  are  shaped,  and  put  aside  in  a 
warm  place  for  an  hour  or  two,  during 
which  they  swell  up  to  about  double 
their  original  size  ;  they  are  then  put  into 
the  oven  and  baked  :  "during  which  ope- 
ration they  again  enlarge  considerably  in 
bulk,  in  consequence  of  the  dilatation  of 
the  previously  generated  carbonic  acid 
pent  up  in  the  dough  ;  for,  as  soon  as  the 
mass  is  exposed  to  the  heat  of  the  oven, 
the  fermentation  is  put  an  end  to. 

II'  we  compare  the  baked  loaf  with  the 
flour  of  which  it  is  composed,  we  shall 
find  that  panary  fermentation  has  pro- 
duced a  considerable  change  in  the  latter. 
The  gluten  and  the  starch,  which  (exclu- 
sive of  a  trace  of  sugar)  were  the  compo- 
nents of  the  flour,  have  mutually  acted 
upon  and  altered  each  other  ;  the  tough- 
ness and  viscidity  of  the  gluten  is  gone, 
and  the  starch  no  longer  forms  a  gelati- 
nous mixture  with  hot  water ;  a  little 
sugar  is  generally  formed,  as  well  as  al- 
cohol; but  the  principal  cause  of  the 
3 


change  in  the  characters  of  the  flour  is 
the  evolution  of  carbon  and  of  oxygen  in 
the  form  of  carbonic  acid,  the  production 
[  of  which  is  independent  of  the  presence 
of  external  oxygen  (or  of  air).  Small 
quantities  of  alum  are  also,  it  is  said, 
invariably  used  with  the  view  of  whiten- 
ing or  bleaching  the  bread  ;  for  it  may  be 
observed,  that  whatever  may  be  the 
quality  of  flour  which  is  used,  home- 
made bread  is  always  of  a  comparatively 
dingy  hue.  According  to  Mr.  Accum, 
the  requisite  quantity  of  alum  for  this 
purpose  depends  upon  the  quality  of  the 
flour.  The  mealman,  he  says,  makes 
different  sorts  of  flour  from  the  same 
kind  of  grain.  The  best  flour  is  chiefly 
used  for  biscuits  and  pastry,  and  the  in- 
ferior kinds  for  bread.  The  smallest 
quantity  of  alum  used  is  from  three  to 
four  ounces  to  the  sack  of  flour  of  240 
pounds. 

Another  article  occasionally  employed 
in  bread-making  is  carbonate  of  ammo- 
nia. As  it  is  wholly  dissipated  by  the 
heat  of  the  oven,  none  remains  in  the 
baked  loaf.  It  renders  the  bread  light, 
and  perhaps  neutralizes  any  acid  that 
may  have  been  formed  (exclusive  of  car- 
bonic acid) ;  but  it  is  too  dear  to  be  much 
employed.  To  some  kinds  of  biscuit  it 
gives  a  peculiar  shortness,  and  a  few  of 
the  most  celebrated  manufacturers  use  it 
largely.  The  French  chemists  have  ac- 
cused the  bakers  of  employing  sulphate 
of  copper  or  blue  vitriol,  for  the  purpose 
of  improving  the  color  of  the  bread ;  but 
so  dangerous  and  easily  detected  an  addi- 
tion can  scarcely  be  supposed  to  be  com- 
mon. According  to  Mr.  E.  Davy,  bread, 
especially  that  of  indifferent  flour,  is 
materially  improved  by  the  addition  of  a 
little  carbonate  of  magnesia,  in  the  pro- 
portion of  twenty  to  thirty  grains  to  the 
pound  of  flour;  it  requires  to  be  very 
intimately  mixed  with  the  dough.  The 
most  nefarious  adulteration  of  bread  con- 
sists, however,  in  the  addition  of  certain 
insipid  and  colorless  earthy  substances, 
with  a  view  of  increasing  its  weight; 
such  as  pipe-clay,  porcelain  clay,  chalk, 
and  plaster  of  Paris.  These,  however, 
are  probably  very  rarely  resorted  to; 
though  in  one  instance  the  writer  of  this 
article  had  occasion  to  examine  a  quantity 
of  biscuits,  which  were  adulterated  with 
gypsum  to  the  amount  of  10  per  cent. 

For  the  manufacture  of  domestic  bread 
the  following,  perhaps,  may  not  be  un- 
acceptable. 

White  Bread. — Take  an  earthen  vessel, 
larger  at  the  top  than  the  bottom,  and 


50 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[bre 


in  it  put  a  pint  of  milk- warm  water,  II 
lbs.  of  flour  and  i  pint  of  good  malt 
yeast ;  mix  these  well  together  and  set  it 
away  (in  winter  it  should  be  in  a  warm 
place)  until  it  rises  and  falls  again,  which 
will  be  in  from  three  to  five  hours.  It 
may  be  set  at  night  if  wanted  in  the 
morning.  Then  put  two  large  table- 
spoons full  of  salt  into  two  quarts  of  wa- 
ter, and  mix  it  well  with  the  above  ris- 
ing. Then  put  in  nine  pounds  of  flour, 
and  work  your  dough  well ;  then  set  it 
by  until  it  becomes  light.  Then  make  it 
out  in  loaves,  of  which  it  will  make  four. 
As  some  flour  is  "  dry,"  and  other  "  run- 
ny," the  above  quantity  will  be  a  guide. 
The  person  making  bread  will  observe 
that  runny,  or  new  flour,  will  require 
one-fourth  more  salt  than  old  or  dry 
flour.  The  water  also  should  be  tem- 
pered according  to  the  weather.  In 
spring  and  fall  it  should  only  be  milk- 
warm.  In  hot  weather  cold,  and  in  win- 
ter warm. 

Brown  Bread. — Take  one  part  of  rye 
meal  and  two  parts  of  Indian  meal,  mix 
it  well,  add  a  little  salt,  and  thoroughly 
wet  the  whole  with  boiling  milk.  Stir  it 
frequently,  until  cold,  and  add  cold  milk 
till  it  is  thin  enough  to  pour  into  pans. 
Bake  it  in  a  brick  oven  five  or  six  hours. 
Take  six  quarts  of  water,  one  teacup 
full  of  salt,  one  pint  of  lard  or  other 
clean  grease,  one  pint  of  yeast,  the  whole 
to  be  quite  warm ;  then  stir  in  meal 
enough  to  make  a  stiff  batter,  let  it  stand 
till  it  rises,  then  mix  up  and  put  in  pans 
to  bake.  The  quanties  can  of  course  be 
reduced  proportionately  as  desired. 

Unfermented  Bread. — Five  pounds  of 
flour,  i  oz.  sesqui  carbonate  soda,  i  dram 
sesqui  carbonate  of  ammonia,  4  teaspoon- 
fuls  of  common  salt.  Mix  well  together, 
and  then  add  2£  pints  (50  oz.)  cold  wa- 
ter, and  5  drams  of  hydrocloric  acid.  It 
requires  li  hours  to  bake. 

The  theory  of panification  (bread-bak- 
ing) is  easy  of  comprehension.  The  flour 
owes  this  valuable  quality  to  the  gluten, 
which  it  contains  in  greater  abundance 
than  any  other  of  the^cerealia  (kinds  of 
corn).  This  substance  does  not  consti- 
tute, as  had  heretofore  been  imagined, 
the  membranes  of  the  tissue  of  the  peris- 
perm  of  the  wheat ;  but  is  inclosed  in 
cells  of  that  tissue  under  the  epidermic 
coats,  even  to  the  centre  of  the  grain. 
In  this  respect  the  gluten  lies  in  a  situa- 
tion analogous  to  that  of  the  starch,  and 
of  most  of  the  immediate  principles  of 
vegetables.  The  other  immediate  prin- 
ciples which  play  a  part  in  panification 


are  particularly  the  starch  and  the  sugar  ; 
and  they  all  operate  as  follows : — 

The  diffusion  of  the  flour  through  the 
water,  hydrates  the  starch  and  dissolves 
the  sugar,  the  albumen,  and  some  other 
soluble  matters.  The  kneading  of  the 
dough,  by  completing  these  reactions 
through  a  more  intimate  union,  favors  al- 
so the  fermentation  of  the  sugar,  by 
bringing  its  particles  into  close  contact 
with  those  ot  the  leaven  or  yeast;  and 
the  drawing  out  and  malaxating  the  dough 
softens  and  stratifies  it,  introducing  at 
the  same  time  oxygen  to  aid  the  ferment- 
ation. The  dough,  when  distributed  and 
formed  into  loaves,  is  kept  some  time  in 
a  gentle  warmth,  in  the  folds  of  the  cloth, 


pans,  &c,  a  circumstance  propitious  to 

^lume  by 
mentation.    The  dimensions  of  all  the 


the  development  of  their  volume  by  fer- 


lumps  of  dough  now  gradually  enlarge, 
from  the  disengagement  of  carbonic  acid 
in  the  decomposition  of  the  sugar ;  which 
gas  i*:  imprisoned  by  the  glutinous  paste. 
Were  these  phenomena  to  continue  too 
long,  the  dough  would  become  too  vesic- 
ular ;  they  must,  therefore,  be  stopped  at 
the  proper  point  of  sponginess,  by  plac- 
ing the  loaf  lumps  in  the  oven.  Though 
this  causes  a  sudden  expansion  of  the 
enclosed  gaseous  globules,  it  puts  an  end 
to  the  fermentation,  and  to  their  growth, 
as  also  evaporates  a  portion  of  their  wa- 
ter. 

The  richness  or  nutritive  powers  of 
sound  flour  and  also  of  bread  are  propor- 
tional to  the  quantity  of  gluten  they  con- 
tain. It  is  of  great  importance  to  deter- 
mine this  point,  for  both  of  these  objects 
are  of  enormous  value  and  consumption  ; 
and  it  may  be  accomplished  most  easily 
and  exactly  by  digesting  in  a  water-bath, 
at  a  temperature  of  167°  F.,  1000  grains 
of  bread  (or  flour)  with  100Q  grains  of 
bruised  barley-malt,  in  5,000  grains  or 
in  a  little  more  than  half  a  pint,  of 
water.  When  this  mixture  ceases  to 
take  a  blue  color  from  iodine  <^that  is, 
when  all  the  starch  is  converted  into  so- 
luble dextrine)  the  gluten  left  unchanged 
may  be  collected  on  a  filter  cloth,  washed, 
dried  at  a  heat  of  212°,  and  weighed. 
The  color,  texture,  and  taste  of  the  glu- 
ten, ought  also  to  be  examined,  in  form- 
ing a  judgment  of  good  flour,  or  bread 
(See  Flour.) 

BKICK.  (Dutch,  bricke.)  In  archi- 
tecture, a  mass  of  clay  earth,  sometimes 
mixed  with  coal  ashes,  chalk,  and  other 
substances,  formed  in  a  mould,  and 
burned  in  a  kiln  or  clamp.  The  earth 
used  for  this  purpose  is  of  two  sorts. 


BRl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


51 


The  one  a  stiff  clay,  with  little  or  no  ex- 
traneous mixture,  which  produces  a  hard 
red  brick  ;  the  other  a  yellowish-colored 
fat  earth,  called  loam,  which  produces  a 
gray-colored  brick.  The  clay  is  usually 
tempered  in  a  clay  mill.  For  the  sea 
coal  ashes  that  are  mixed  with  it  in  cities, 
they  substitute  in  the  country  a  light 
sandy  earth.  In  making  the  paste  as  lit- 
tle water  should  be  introduced  as  possi- 
ble. In  moulding  them,  which  is  done 
in  a  wooden  mould,  a  clever  workman 
will  mould  about  five  thousand  in  fifteen 
hours.  The  kiln  in  which  they  are  burnt 
is  a  large  building,  about  13  feet  long,  10 
feet  6  inches  wide,  and  12  feet  high,"" fur- 
nished with  a  proper  furnace.  When 
otherwise  burnt,  the  clamp,  as  it  is  called, 
is  formed  of  the  bricks  themselves,  gene- 
rally oblong  on  the  plan,  and  the  founda- 
tions made  with  place  bricks.  Each 
course  of  bricks  is  laid  on  a  layer  of 
breeze  or  cinders :  and  flues  are  formed, 
filled  with  coals,  breeze,  and  wood.  The 
burning  continues  from  twenty  to  thirty 
days.  The  size  of  bricks,  when  burnt, 
is  'required  in  England  to  be  84  inches 
long,  2i  inches  thick,  and  4  inches  wide. 
The  different  varieties  of  bricks  are, 
malms,  which  are  of  a  yellowish  uniform 
color  and  texture ;  seconds,  not  quite  so 
uniform  in  color  and  texture  as  malms  ; 


red  and  qrey  stocks,  the  former  being 
burnt  in  kilns,  both  of  a  quality  rather 
inferior  to  seconds  ;  place  bricks  or  peck- 
iii'js,  sometimes  called  sandel  or  samel 
bricks,  which  are  those  furthest  from  tho 
fire,  and  rarely  well  burnt,' — these  should 
never  be  used  in  a  building  where  dura- 
bility is  required ;  burrs  or  clinkers, 
which  are  masses  of  several  bricks  run 
together  in  the  clamp  or  kiln  from  the 
violent  action  of  the  fire  ;  fire  bricks,  of 
a  red  color,  about  9  inches  lon^r,  4i  inches 
broad,  and  an  inch  and  a  half  thick, — 
they  are  made  for  use  in  furnaces  to  re- 
sist the  action  of  the  fire,  and  from  having 
been  formerly  manufactured  in  the  neigh- 
borhood of  Windsor,  they  are  sometimes 
called  Windsor  bricks ;  paving  bricks, 
made  for  the  purpose  their  name  implies ; 
compass  bricks,  are  circular  on  the  plan, 
chiefly  used  in  walling  wells  and  the  like ; 
Dutch  clinkers  or  Flemish  bricks,  chiefly 
used  in  stables  ;  the  Dutch  clinkers  6 
inches  long,  8  inches  broad,  and  1  inch 
thi^k. 

The  moulding  of  bricks  in  tins  country 
is  altogether  performed  by  machinery; 
one  of  the  latest  improvements  in  which 
is  the  invention  of  J.  Z.  A.  Wagner,  of 
Philadelphia,  of  which  the  annexed  is  an 
illustration. 


This  machine  consists  of  a  large  re- 
volving metal  wheel,  which  has  a  num- 
ber of  boxes  in  its  periphery,  of  the  form 
of  the  brick  to  be  moulded,  and  which 
constitute  the  moulds.    In  the  inside  of 


these  moulds  are  plungers,  which  recede 
to  allow  the  clay  to  come  in  for  mould- 
ing, but  when  they  come  to  an  endless 
apron  below,  a  earn  acts  upon  the  said 
plungers,  and  they  push  out  the  bricks, 


52 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lIRI 


delivering  them  on  the  endless  apron  to 
be  carried  away.  This  is  an  outline  of 
its  main  working  features.  A  is  the  me- 
tal base  of  the  machine ;  B  is  the  frame  ; 
0  is  a  pully  on  the  shaft  of  the  mould 
wheel,  E.  'The  rims  of  the  mould  wheel 
are  made  of  toothed  gearing,  and  gear 
into  wheels,  F  (one  on  each  side),  of  a 
pressure  metal  roller,  which  works  close 
up  against  the  face  of  the  mould  wheel, 
excepting  that  part  opposite  the  moulds, 
which  is  a  little  recessed  all  around,  leav- 
ing a  space  between  the  two ;  D  is  a  pul- 
ley to  drive  the  drum  0  (fig.  2),  of  the 
endless  apron,  J.  G  is  the  hopper  to  re- 
ceive the  prepared  clay.  This  hopper  is 
supported  by  screw  rods  or  posts,  M 
(one  on  each  side).  The  hopper  has  a 
rim  which  fits  snugly  into  recesses  in 
the  mould  wheel,  and  the  pressure  roller, 
F,  to  keep  the  clay  from  getting  between 
the  teeth  of  the  wheels.  In  case,  how- 
ever, that  the  moulded  brick  might  stick  to 
the  end  of  the  plunger,  Mr.  Wagner  has 
attached  a  lever  on  each  side,  secured  to 
the  inside  of  the  frame,  B,  under  the 
mould  wheel  and  above  the  apron,  and 
the  end  of  these  levers  are  touched  by 
cams  on  each  side  of  the  mould  wheel 
(one  cam  for  each  mould)  when  the  lever 
immediately  pushes  the  moulded  brick 
from  contact  with  the  mould  wheel,  and 
it  drops  on  the  carrying'  apron.  The  first 
roller,  F,  acts  like  a  feeoTroller  to  pack  the 
moulds  with  the  clay,  but  leaving  a  little 
clay  projecting  out,  and  then  the  second 
pressure  roller,  by  being  placed  closer  to 
the  face  of  the  moulds,  presses  the  clay 
solidly  into  the  moulds,  and  smooths  the 
face  of  the  brick.  This  is  a  rotary  brick 
moulding  machine. 

Mr.  H.  Roberts,  of  Hyde  Park,  London, 
has  lately  taken  out  a  patent  for  a  new 
kind  of  bricks,  which  are  so  made  that 
there  will  be  no  vertical  joints  in  the 
wall  which  may  be  built  of  them,  as  are 
now  made  by  the  headers,  where  the 
English  and  Flemish  bonds  are  used. 
The  bricks  are  made  hollow  to  be  lighter. 
They  are  made  so  that  one  side  of  the 
brick  is  inclined  to  the  top  or  the  bottom, 
or  the  one  part  projecting  beyond  the 
other,  so  that  one  brick  being'  laid  the 
other  is  to  be  reversed,  so  that  the  pro- 
jecting sides  of  the  bricks  will  fit  into 
one  another,  to  bond  the  work,  using 
only  stretchers  to  avoid  vertical  joints. 

Mr.  Legros  has  taken  out  a  patent  in 
London  for  machines  to  mould  bricks, 
tiles,  and  other  articles,  by  which  supe- 
rior produce  is  obtained  at  less  cost.  In 
one  of  his  inventions  Mr.  L.  lias  adapted 


the  principle  of  motion  on  a  small  rail- 
way to  the  performance  of  the  several 
steps  of  the  manufacture.  For  this  pur- 
pose rails  are  laid  down  so  as  to  traverse 
on  the  same  level  all  the  buildings  in 
which  the  various  parts  of  the  machin- 
ery are  erected.  One  machine  will  turn 
out  66  bricks  in  a  minute,  or  40,000  in  a 
day,  at  an  economy  of  one  dollar  per 
thousand. 

BRIDGE.  (Sax.  brigge.)  In  Archi- 
tecture, a  structure  for  the  purpose  of 
connecting  the  opposite  banks  of  a  river, 
gorge,  valley,  &c.  &c,  by  means  of  cer- 
tain materials,  forming  a  roadway  from 
one  side  to  the  other.  It  may  be  of 
stone,  brick,  iron,  timber,  suspended 
chains  or  ropes ;  or  the  roadway  may  be 
formed  by  means  of  boats.  Long  previ- 
ous to  the  introduction  of  bridges  con- 
structed upon  geometrical  principles,  the 
modes  of  crossing  rivers  by  throwing  the 
trunks  of  trees  across  them,  or  by  sus- 
pension of  ropes,  or  twisting  together 
the  branches  of  trees  from  bank  to'bank, 
were  so  obvious  that  they  must  have  been 
resorted  to  at  an  early  period.  The 
former  method,  however,  could  only 
have  been  practised  over  narrow  streams, 
whilst  the  latter  might  have  been  carried 
to  almost  any  required  extent.  Mungo 
Park  found  this  mode  employed  in  Afri- 
ca ;  and  in  South  America  rope  bridges 
of  bujuco,  or  thongs  made  from  the  hides 
of  oxen,  are  in  use  at  the  present  day. 
Don  Antonio  de  Ulloa  tells  us,  that  over 
some  of  the  rivers  of  Peru  the  bujuco 
bridges  are  of  such  dimensions  that 
loaded  mules  in  droves  pass  over  them, 
and  especially  on  the  river  Apurimac, 
forming  the  liigh  road  for  the  trade  car- 
ried on  between  Lima,  Cuzco,  and  other 
places  to  the  southward.  Though  such 
bridges  are  the  contrivance  of  man  in  a 
less  civilized  state,  they  are  the  only 
means  by  which  many  streams  whose 
currents  are  deep  and  rapid  can  be 
crossed ;  and  the  stupendous  suspension 
bridges  of  the  present  day  are  but  im- 
provements on  the  simple  scheme  of  the 
untutored  architect  of  a  savage  period 
and  people. 

The  use  of  the  arch  in  bridging  ap- 
pears to  have  been  first  practically  ap- 
plied by  the  Romans.  The  Chinese, 
though  using  the  arch,  did  not  make  it 
strong  enough  to  bear  wheel  carriages. 
In  Egypt  and  India  it  was  unknown,  or 
was  not  applied.  There  is  no  trace  of 
the  arch  in  the  ancient  works  of  Plienicia 
and  Persia,  and  even  the  Greeks  have  a 
doubtful  claim  to  it.     Over  the  Tiber  the 


'] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


53 


ancient  Romans  built  -wooden  bridges ;  J 
such  was  that  which  joined  the  Janicu- 
lum  to  the  Mons  Aventinus,  and  was 
called  the  Pons  Sublicius,  from  the  word  j 
suhlLcce  (stakes)  of  which  it  was  formed. 
Without  enumerating  the  bridges  of  | 
Koine,  some  of  which  are  still  standing 
to  attest  the  science  of  their  architects, 
wc  must  mention  the  Pons  Narniensis, 
on  the  Flaminian  way,  near  Narni,  and 
about  sixty  miles  from  Rome.  It  was 
built  by  Augustus,  and  vestiges  of  it  re- 
main to  the  present  day,  one  arch  above 
150  feet  span  and  100  feet  high  being 
still  entire.  But  of  works  of  art,  perhaps 
the  most  wonderful  ever  raised  was  the 
bridge  built  by  Trajan  over  the  Danube. 
It  consisted  of  twenty  piers,  whose  height 
from  their  foundation  was  150  feet,  and 
170  feet  apart ;  its  breadth  being  sixty 
feet.  This  stupendous  work  was  demo- 
lished by  Hadrian,  the  successor  of  Tra- 
jan, under  the  pretence  that  it  might 
serve  as  a  passage  for  the  barbarians,  if 
they  became  masters  of  it ;  but  some 
writers  have  said  it  was  through  envy 
of  the  fame  that  attached  to  its  founder. 
Over  the  Tagus,  in  Spain,  an  ancient 
Roman  bridge,  near  Alcantara,  is  still 
partly  standing.  It  consisted  of  six 
arches  of  eighty  feet  span,  extending  al- 
together 600  feet  in  length,  and  some  of 
the  arches  200  feet  high  above  the  water. 
Of  the  temporary  bridges  of  the  Romans, 
the  most  famous  was  that  of  timber 
thrown  by  Caesar  over  the  Rhine. 

From  the  fall  of  the  Roman  Empire  to 
the  revival  of  the  arts,  the  history  of 
bridge  architecture  is,  with  the  exception 
of  the  Moorish  works  in  Spain,  of  no  in- 
terest. It  appears  from  Gautier,  who 
uses  the  authority  of  Mag.  Agricola  of 
Aix,  that  when  the  arts  beganto  revive 
in  Europe,  an  order  was  founded  by  St. 
Benezet,  under  the  title  of  Brethren  of 
the  Bridge ;  and  that  under  them  was 
begun,  in  1176,  the  bridge  at  Avignon, 
consisting  of  eighteen  arches  and  about 
3000  feet  in  length.  During  the  conten- 
tions of  the  popes,  in  1385,  some  of  its 
arches  were  destroyed,  and  in  1602  three 
others  fell.  In  1670  the  ice  destroyed  all 
but  the  third  pier,  which,  with  the  Cha- 
pel of  St.  Nicholas  upon  it,  still  remains. 
In  1354  a  bridge  of  three  arches  was  con- 
structed at  Verona,  the  roadway  sloping 
from  the  city ;  the  largest  of  its  arclies, 
which  are  segmental,  is  160  feet  span ; 
but  a  still  larger  arch  was  built  at  Vielle- 
Brioude  in  France,  over  the  Allier,  in 
1454,  of  nearly  184  feet  span,  which  is  the 
largest  stone  arch  upon  record.    Among 


the  most  celebrated  bridges  of  Italy,  is 
that  of  the  Rialto  at  Venice,  whose  span 
is  98i  feet.  It  was  begun  in  1588,  and 
finished  in  1591,  from  the  designs  of 
Antonio  dal  Ponte,  though  by  most  au- 
thors absurdly  attributecf  to  M.  A.  Buo- 
narroti. In  this  city  alone  there  are  no 
less  than  339  bridges;  but  they  are 
mostly  of  small  spans.  We  must  not 
omit  in  this  place  the  bridge  of  Delia 
Santissima  Trinita,  at  Florence,  by  Am- 
manati,  which,  as  Milizia  truly  observes, 
has  not  been  surpassed  since  the  revival 
of  architecture.  It  is  of  three  arches,  the 
middle  one  of  96  and  the  two  side  ones 
86  feet  span,  the  width  of  the  piers  being 
26  feet  9  inches  ;  the  breadth  of  the  car- 
riage and  footways  between  the  parapets 
is  33  feet.  It  has  been  usual  for  writers 
to  call  the  form  of  the  arches  of  this 
bridge  cycloidal ;  but  from  our  own  mea- 
surements and  most  particular  investiga- 
tion, we  can  assert  that  they  are  not  of 
that  form.  They  are  very  slightly  pointed, 
after  the  fashion  of  what  is  called  the  Tu- 
dor arch  of  this  country ;  the  point  at 
the  summit,  which  is  extremely  obtuse, 
being  hidden  by  the  ram's  head  sculp- 
tured on  the  key-straes.  During  the 
two  last  centuries,  the  French  have  ad- 
vanced their  bridge  architecture  to  very 
great  perfection ;  but  more  particularly 
in  the  latter  part  of  the  last  century,  in 
which  appeared  Perronet,  the  father  of 
the  modern  system  of  the  art,  whose 
elegant  designs  have  not  since  been  im- 
proved upon,  either  in  France  or  in  any 
other  country.  His  is  the  beautiful 
bridge  of  Neuilly  over  the  Seine.  It  con- 
sists of  five  arches,  each  about  128  feet 
span  and  32  feet  rise  :  it  was  finished  in 
1774,  and  remains  a  splendid  monument 
of  the  powers  of  its  architect.  Some  of 
the  more  modern  specimens  of  their 
bridges  do  great  honor  to  the  French 
school,  in  which  beauty  of  form  is  united 
with  sound  engineering. 

In  England,  the  progress  of  bridge  ar- 
chitecture has  kept  pace  with  that  of  the 
Continent;  and  if  her  bridges  cannot 
boast  the  elegance  in  design  of  her 
lively  neighbors,  they  are  fully  equal  to 
them  in  boldness  of  conception  and  exe- 
cution of  the  work.  Indeed,  if  the  de- 
signs of  the  late  Messrs.  Telford  and 
Rennie  had  been  equal  to  their  engin- 
eering skill,  no  country  in  the  world 
would  have  been  able  to  compete  with 
what  she  would  have  been  able  to  exhibit. 
And  here  must  not  be  forgotten  the 
bridge  over  the  river  Taaf,  near  Llan- 
trissart,   in  Glamorganshire,   celebrated 


54 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


b 


for  its  great  span ;  the  work  of  William  ; 
Edwards,  a  country  mason,  in  1765.  The 
chord  line  is  140  feet,  and  the  versed 
sine  35  feet. 

Of  timber  bridges  the  boldest  and 
most  ingeniously  constructed  was  that  at 
SchafFhausen,  in  Switzerland,  destroyed 
by  the  French  in  1799.  It  was  designed 
and  executed  by  Grubenman,  a  common 
carpenter,  in  1758.  The  total  length  of 
the  bridge  was  364  feet,  but  it  was  re- 
lieved by  a  pier  in  the  middle  of  the 
river. 

This  country  has  some  of  the  grandest 
specimens  of  timber  bridges  in  the  world. 
The  Colossal  bridge  over  the  Schuylkill, 
at  Philadelphia  (since  burnt)  was  340 
feet  span,  with  a  rise  of  only  20  feet,  and 
the  thickness  of  the  timber  at  the  vertex 
only  7  feet.  That  at  Piscataqua,  over 
the  river  of  same  name,  has  a  span  of 
250  feet,  and  a  rise  of  27,  built  in  1794  by 
Palmer. 

The  bridge  of  the  Kennebec  and  Port- 
land Railroad,  over  the  Androscoggin 
River  at  Topsham,  is  one  of  the  largest  and 
most  substantial  structures  of  the  kind  in 
the  United  States.  It  is  a  deck  bridge, 
the  upright  posts  and  rods  being  about 
18  feet  from  the  lower  to  the  upper  deck. 
One  of  them  reaching  from  centre  to  cen- 
tre of  the  piers,  is  one  hundred  and 
eighty  feet.  The  piers  are  of  granite 
laid  in  the  most  durable  manner.  The 
whole  length  of  the  bridge  is  over  seven 
hundred  feet.  The  track  of  the  road 
along  the  upper  deck  will  be  about  fifty 
feet  above  tide  water.  The  large  lower 
and  upright  timbers,  and  the  iron  work, 
together  with  the  X  work  between  decks, 
give  the  bridge  an  appearance  of  strength 
and  solidity  sufficient  for  any  weight. 

Suspension  bridges  derive  their  chief 
value  from  the  fact  of  their  independence 
of  the  bed  of  the  river.  Hence  they 
may  be  used  where  it  is  impossible  from 
the  force  of  the  current  or  the  altitude  of 
the  banks  to  erect  centreing  for  a  stone 
bridge.  They  are  built  with  ease  and 
expedition,  and  are  economical.  The 
celebrated  suspension  bridsre  over  the 
Menai  Strait,  by  the  late  Mr.  Telford, 
is  almost  the  giant  of  its  species,  and 
renders  unnecessary  any  enumeration 
of  others.  It  consists  of  one  opening  of 
560  feet  between  the  points  of  suspen- 
sion, the  height  between  high  water  and 
the  under  side  of  the  roadway  being  100 
feet.  The  platform  is  30  feet  in  breadth. 
The  whole  is  suspended  from  four  lines 
of  strong  iron  cables  by  perpendicular 
rods  5  feet  apart.    On  the  tops  of  the  pil- 


lars the  cables  pass  over  iron  rollers,  and 
are  fixed  under  ground  to  iron  frames, 
which  are  retained  in  their  places  by  ma- 
sonry. The  weight  of  the  whole  bridge 
between  the  points  of  suspension  is  489 
tons.  In  suspension  bridges  it  has  been 
found  that  the  most  trying  circumstances 
under  which  they  can  be  placed,  as  af- 
fecting the  stability  of  their  equilibrium, 
is  the  heavy  and  measured  tread  of  a  long 
line  of  infantry,  whose  feet  drop  at  the 
same  instant  of  time. 

The  wire  suspension  bridge  at  Wheel- 
ing, Va.,  over  the  Ohio,  has  been  com- 
pleted by  Charles  Ellett,  Jr.,  Architect. 
The  flooring  is  supported  by  12  cables  of 
iron,  each  cable  4  inches  in  diameter, 
composed  of  550  strands  of  No.  10  wire, 
and  is  1,380  feet  long  ;  and  from  centre 
to  centre  of  the  abutments,  the  flooring 
is  1,010  feet  long,  24  feet  wide,  with  two 
foot-ways,  each  3£  feet,  and  an  interme- 
diate carriage-way  17  feet  wide.  The 
cables  rest  on  iron  rollers,  placed  on  the 
summits  of  the  towers,  the  movements 
of  which  will  relieve  the  towers  of  the 
strain,  and  are  anchored  into  the  heavy 
masonry  of  the  wing  walls  at  each  end  of 
the  bridge.  The  length  of  the  wood- 
work which  rests  on  the  cables  is  960 
feet ;  its  weight  546  lbs.  per  lineal  foot, 
or  524,160  pounds  of  262  tons  in  the 
whole.  The  weight  of  each  lineal  foot 
of  the  12  cables,  composed  of  6,600 
strands,  is  330  pounds,  making,  with  the 
weight  of  timber,  bolts,  castings,  sus- 
penders, &c,  920  lbs.  per  lineal  foot,  or 
441  tons  as  the  permanent  weight  of  the 
bridge  itself.  Above  its  own  weight  the 
bridge  is  constructed  to  support  the 
greatest  transitory  weight  that  is  ever 
likely  to  be,  or  we  may  say,  can  possibly 
be  brought  upon  it,  such  as  two  columns 
of  teams,  and  the  sides  loaded  with  men, 
so  as  to  weigh,  jointly,  297  tons,  or  the 
average  weight  of  4,000  men,  and  the 
strength  of  the  bridge  is  calculated  to 
support  three  times  t'Ae  amount  of  ten- 
sion that  ever  can  be  brought  to  bear 
upon  it.  This  bridge  will  no  doubt  last 
long  as  a  monument  of  American  skill 
and  enterprise. 

The  wire  suspension  bridge  erected 
across  the  Cumberland  River  at  Nash- 
ville has  the  following  measurements. 
The  length  of  the  bridge  is  656  feet,  and 
the  whole  lencrth  of  the  bridge  and  em- 
bankment 1,956  feet.  Width  of  super- 
structure, 28  feet ;  carriage  way,  20 ;  two 
footways,  each  4  feet.  The  bridge  will 
span  the  Cumberland  opposite  the  south- 
east corner  of  the  public  square  of  tho 


BRl] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


55 


city,  at  an  elevation  of  110  feet  above 
low  water,  over  the  main  steamboat 
channel.  Base  of  pier,  60  by  20  feet, 
solid  mason  work ;  anchorage,  60  by  56 
on  the  north  side ;  solid  limestone  clitf 
on  the  south  side.  There- are  to  be  16 
cables,  each  cable  composed  of  200 
strands  of  No.  10  wire,  each  wire  tested 
to  bear  1500  lbs.  The  whole  work  is 
calculated  to  bear  a  weight  of  4,800,000 
lbs.,  or  2400  tons.  The  cost  of  this  mag- 
nificent structure  is  estimated  at  but 
$100,000,  though  the  Wheeling  Bridge, 
1010  feet  long,  "cost  $225,000. 

The  wire  suspension  bridge  over  the 
Niagara  River  is  the  largest  of  its  kind 
in  the  world.  It  is  built  over  the  river 
H  miles  below  the  Falls,  and  directly 
over  the  rapids,  which  commence  at  this 
point.  It  is  nearly  800  feet  long,  and  260 
feet  above  the  river.  Towers  80  feet 
high  are  erected  on  the  bank  each  side, 


and  at  a  point  100  feet  in  their  rear  the 
immense  wire  cables  which  sustain  the . 
bridge  are  firmly  secured.  These  strands 
pass  from  their  fastenings  immediately 
over  the  top  of  the  tower  upon  either 
clitf ;  they  pass  thence  across  the  chasm, 
and  then  over  the  top  of  the  tower  on 
the  opposite  cliff,  in  the  rear  of  which 
the  ends  are  fastened  in  the  rock.  It  is 
10  feet  wide,  and  a  temporary  path  of  wire 
and  slats  of  wood  has  been  constructed 
on  each  side.  The  flooring  is  composed 
of  light  planks  resting  upon  their  scant- 
lings, to  which  the  wires  are  fastened. 
Mr.  Ellett  is  the  architect. 

Mr.  Dredge,  of  Bath,  England,  builds 
his  suspension  bridge  on  a  very  improved 
plan,  hi  which  bars  connected  the  road- 
way to  the  catenary  chain,  are  not  verti- 
cal, as  in  other  suspension  bridges,  but 
are  made  by  him  to  pass  obliquely  from 
the  tower  toward  the  centre,  as  shown 


>^^N^^^^ 


in  the  cut,  where  C  represents  the  cen- 
tre, B  the  tower,  and  E  the  platform ;  g 
shows  the  point  to  which  dependence  on 
the  tower  extends :  this  tends  to  strength- 
en the  bridge  considerably.  The  chains 
in  his  bridge  are  made  of  great  thick- 
ness at  the  points   of  suspension,   and 


taper  off  to  the  middle  of  the  bridge, 
where  the  strain  is  least.  Mr.  Dredge 
has  erected  in  England,  Ireland,  and 
Scotland,  many  bridges  on  this  plan, 
which  are  models  of  "cheapness,  beauty, 
and  durability. 


This  represents  a  portion  of  the  bridge 
at  Ballock  Ferry,  Loch  Lomond,  Scotland, 
erected  on  that  principle. 

Mr.  Eemington  has  planned  a  bridge 
which  appears  to  be  the  simplest  as  yet 
designed,  and  is  remarkably  cheap  in 
construction,  according  to  the  length  of 
span.      Models  of  his' bridge  have  been 


exhibited  in  New- York  and  the  other 
cities  of  the  Union,  as  well  as  in  London. 
That  exhibited  in  New-York  was  160  feet 
in  the  clear,  composed  of  four  stringers 
of  a  little  over  two  inches  square  at  the 
abutments,  and  tapering  to  about  an  inch 
square  at  the  centre.  It  is  of  the  form  of 
an  inverted  arch.  The  stringers  are  made 


56 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[bri 


of  several  pieces  of  white  pine  joined  to- 
gether by  a  scarfe  joint ;  their  ends,  when 
they  are'joined,  being  bevelled  at  a  very 
slight  angle,  and  the  bevelled  parts  lapped 
over  each  other,  and  attached  with  glue, 
so  that  when  united,  each  Btringer  ap- 
pears to  be  a  continuous  and  single  piece. 
These  jointings  are  so  arranged  as  that 
only  one  of  them  ever  occurs  in  the  same 
cross  section  of  the  bridge,  and  they  are 
neither  bolted  nor  clamped,  but  depend 
entirely  upon  the  glue  for  their  adhesion. 
Each  of  these  stringers  have  about  nine 
feet  bearing  on  the  abutments  or  suspen- 
sion piers,  to  which  they  are  firmly  at- 
tached by  iron  bolts. 

At  New  Orleans,  Mr.  E.  exhibited  a 
model,  extending  "  across  a  space  of  nine- 
ty-six feet,  and  eievated  some  ten  feet  from 
the  floor.  Its  appearance  is  so  fragile, 
that  few  men,  judging  from  this  alone, 
would  willingly  trust  themselves  upon  it, 
yet  plenty  walk  over  it  and  stand  on  it. 
It  has  four  longitudinal  supporters,  each 
less  than  one  inch  square  at  the  centre, 
but  increasing  gradually  in  size,  until  at 
the  ends  or  points  fastening,  they  are  2i 
inches  square.  The  bridge  has  one  caten- 
ary and  two  parabolic  curves,  by  which 
strength  and  beauty  are  both  secured. 
The  flooring  is  attached  diagonally,  and 
is  made  to  sustain  a  portion  of  the  strain. 
The  deflexion  of  the  supporters  is  22* 
inches.  It  is  capable  of  bearing  the  pres- 
sure of  7  tons ;  while  each  of  the  support- 
ers, occupying  their  place  in  the  bridge, 
will  sustain  a  weight  greater  than  the  ab- 
solute strength  of  the  timber  and  the  di- 
rect cohesion  of  its  fibres." 

Upon  this  pin  n,  Mr.  Remington  has 
erected  one  in  Montgomery,  Alabama, 
that  was  opened  for  travel  last  year. 
The  span  is  436  feet,  and  the  track  is 
10  feet  wide.  It  is  without  hand-rails, 
and  is  described  as  appearing  at  a  dis- 
tance like  a  slight  ribbon,  or  shaving  of 
wood,  flung  across  a  ravine — apparently 
too  frail  to  bear  the  pressure  ot  a  bird, 


but  proved  to  be  capable  of  bearing  al- 
most any  amount  of  weight  that  can  be 
placed  upon  it.  Hundreds  of  people 
crossed  it  on  the  day  it  was  opened,  who 
were  completely  convinced  of  its  strength. 
Its  strength  is  due  to  the  fact  that  the 
fibres  of  the  stringers  are  not  subject  to 
any  transverse  strain,  the  only  action 
upon  them  being  exerted  in  the  direction 
ot  the  length  of  the  fibre.  Each  end  of 
one  of  its  stringers  is  firmly  bolted  down 
to  an  abutment,  and  any  weight  being 
laid  upon  them  between  the  abutments, 
causes  just  the  same  tension  of  the  fibres 
as  in  the  case  of  an  attempt  to  break  a 
walking-stick  by  drawing  it  apart,  while 
holding  the  ends. 

Wiebiking  states  that  a  rise  of  1  in  24 
is  a  convenient  ascent  for  a  bridge.  In 
timber  bridges  the  settlement  is  1  in  72 : 
that  is,  if  a  timber  bridge  of  144  feet  span 
rise  one  foot  in  the  middle  when  first 
framed,  it  will  settle  so  as  to  be  horizon- 
tal ;  so  that  when  it  is  intended  for  the 
bridge  to  have  an  ascent  of  1  in  24  when 
finished,  it  must  be  framed  so  as  to  have 
a  rise  of  1  in  18 :  for  -^  =  2V +  ^. 

The  Britannia  Tubular  Bridge  is  one  of 
the  most  remarkable  structures  in  the 
world,  the  design  of  the  celebrated  Ar- 
chitect, Sir  E.  Stephenson.  This  bridge 
is  on  the  line  of  the  Chester  and  Holyhead 
Railway,  crossing  the  Menai  Straits, 
within  sight  of  Telford's  Chain  Suspen- 
sion Bridge.  It  is  made  of  cast  iron  of 
a  tubular  form,  in  the  tube  of  which  the 
railway  passes.  Four  of  these  span  the 
Strait,  and  are  supported  by  piles  of  ma- 
sonry; that  on  the  Anglesey  side  is 
143  feet  6  inches  high,  and  from  the  front 
to  the  end  of  the  wing  walls  is  173  feet. 
These  wing  walls  terminate  in  pedestals, 
on  which  repose  colossal  lions  of  Egyptian 
character.  The  Anglesey  pier  is  196  feet 
high,  55  feet  wide,  and  32  feet  long.  In 
the  middle  of  the  Strait  is  the  Britannia 
Eock,  from  which  the  bridge  derives  its 
name  ;  on  this  the  Britannia  pier  is  raised. 
It  is  equally  distant  from 
the  Anglesey  and  Caernar- 
von piers,  being  460  feet 
in  the  clear  from  each,  and 
sustains  the  four  ends_  of 
the  four  long  tubes,  which 
span  the  distance  from 
shore  to  shore.  There  are 
two  pair  of  short  and  two 
*"  of  long  tubes,  the  lengths 
of  these  pairs  being  250 
feet  and  470  respectively. 
Tho  Egyptian  lions  are  25 
feet  6  inches  long,  12  feet 


BRO] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


57 


6  inches  high,  8  feet  wide,  and  weigh  80 
tons.  Two  thousand  cubic  feet  of  stone 
were  required  for  each  lion.  The  total 
quantity  of  stone  in  the  bridge  is  1,400,000 
cubic  feet.  The  weight  of  malleable  iron 
in  the  tubes  is  10,000  tons,  of  cast  iron, 
1,400  tons.  The  whole  length  of  the  en- 
tire bridge,  measuring  from  the  extreme 
front  of  the  wing  walis,  is  1,833  feet,  and 
its  greatest  elevation  at  Britannia  pier, 
240  feet  above  low-water  mark.  The 
total  cost  of  the  structure  is  £601,865. 

The  following  observations  refer  to  the 
arrangement  of  parts  in  ordinary  bridg- 
ing : 

In  the  building  of  bridges,  where  piers 
are  required  in  the  stream  for  the  support 
of  the  arches,  it  is  important  to  place 
them  as  nearly  as  possible  at  right  angles 
to  the  stream  or  current ;  and  the  piers 
should  be  made  convex  towards  the 
stream,  for  their  better  resistance  to 
floods.  The  position  of  a  bridge,  more- 
over, should  not  be  in  a  narrow  part,  nor 
one  liable  to  swell  with  tides  or  floods, 
inasmuch  as  the  contraction  of  the  water- 
way increases  the  depth  and  velocity  of 
the  current,  and  may  thus  endanger  the 
navigation  as  well  as  the  bridge  itself.  It 
is  usual  to  construct  bridges  with  an  odd 
number  of  arches,  and  this  on  several  ac- 
counts :  among  which  arc,  that  the  stream 
being  usually  most  powerful  in  the  mid- 
dle, an  egress  through  that  part  is  best 
provided  for  by  having  a  central  arch  ; 
and  again,  if  the  bridge  be  not  perfectly 
horizontal,  symmetry  is  gained  by  rising 
from  the  sides  to  the  centre,  and  the 
whole  roadway  may  be  made  one  con- 
tinued curve.  When  a  bridge  is  equally 
high  throughout,  much  saving  of  cen- 
tring is  made,  because  the  arches  being  all 
equal,  two  sets  of  centres  will  be  sufficient. 
If,  however,  the  bridge  be  higher  in  the 
middle  than  at  the  extremities,  the  arches 
on  each  side  the  centre  one  must  dimin- 
ish similarly,  so  as  to  be  respectively 
symmetrical;  and  by  this  arrangement 
beauty  is  gained,  and  the  centring  for 
one  side  equally  suits  the  other.  It  is  de- 
sirable to  construct  a  bridge  with  as  few 
arches  as  circumstances  will  allow,  that 
there  may  be  a  free  passage  for  the  water, 
aa  well  as  for  the  vessels  tha.  have  to  pass 
up  and  down,  not  to  mention  the  saving 
ot  materials  and  labor  where  there  are 
fewer  piers  and  centres.  When  a  single 
arch  can  be  compassed,  no  more  should 
be  permitted.  The  piers  should  be  of 
sufficient  solidity  to  resist  the  thrust  or 
push  of  the  arch,  independent  of  other 
arches,  so  that  the  centring  of  an  arch 
3* 


may  be  struck  without  danger  of  over- 
turning the  pier  left  naked ;  and  the  piers 
should' also  be  spread  as  much  as  possible 
on  the  bases,  and  diminish  gradually  up- 
wards from  their  foundations.  The  me- 
thod of  laying  the  foundations  in  a  river 
is  now  usually  by  means  of  coffer-dams, 
which  are  large  inclosures,  made  by  pil- 
ing round  the  space  to  be  occupied  by  the 
pier,  so  as  to  render  it  water-tight,  and 
then  pumping  out  the  water,  and  keeping 
the  space  dry  till  the  pier  is  built  up  to 
the  ordinary  level  of  the  water ;  but  if  the 
ground  about  be  loose,  this  method  can- 
not be  well  practised,  and  recourse  is  had 
to  caissons,  which  are  a  species  of  flat- 
bottomed  boat,  in  which  the  pier  is  built 
up  to  a  certain  height,  and  then  sunk 
over  the  place  where  it  is  intended  to  re- 
main, the  bed  of  the  river  being  dredged 
out  to  receive  it,  or  piles  driven  on  which 
it  may  lodge  when  the  sides  of  the  chest 
or  caisson  are  knocked  away.  In  con- 
structing the  centres,  great  care  must  bo 
taken  to  make  them  incapable  of  bending 
or  swerving  while  the  arch  is  being 
turned,  otherwise  the  form  of  the  arch 
will  be  crippled. 

BRIMSTONE.    (See  Sulphur.) 

BRINE.     (See  Salt.) 

BRITISH  GUM.  When  starch  is  ex- 
posed to  a  temperature  of  about  600°,  it 
Becomes  of  a  brownish  color,  and  so  far 
altered  in  its  chemical  character  as  no 
longer  to  form  a  blue  color  with  iodine  : 
it  is  also  soluble  in  cold  water.  In  this 
state  it  is  used,  under  the  above  name, 
by  calico  printers. 

BROMINE.  (Gr.  /fyw/jos,  a  strong 
odor.)  An  undecompounded  substance, 
discovered  in  1826  by  M.  Balard  of  Mont- 
pelier.  In  its  general  chemical  habitudes 
it  much  resembles  chlorine  and  iodine, 
and  is  generally  associated  with  them.  It 
exists,  but  in  very  minute  quantities,  in 
sea-water,  and  in  the  ashes  of  marine 
plants.  It  is  usually  extracted  from  bit- 
tern by  the  agency  of  chlorine.  At  com- 
mon temperatures  it  is  a  very  dark  red- 
dish liquid,  of  a  powerful  and  suffocating 
odor,  and  emitting  red  vapor.  Its  spe- 
cific gravity  is  about  3.  It  boils  at  116°, 
and  congeals  at  4°.  The  density  of  its 
vapor  is  5*5 ;  100  cubic  inches  at  mean 
temperature  and  pressure  weighing  167*25 
grains.  It  is  an  electro-negative  ;  it  lias 
bleaching  powers,  and  it  is  very  poison- 
ous. Its  equivalent  number  is  about  78  ; 
it  combines  with  hydrogen  to  form  hydro- 
bromw  acid  gas,  100  cubic  inches  of  which 
weigh  84*7  grains.  With  oxygen  it  forms 
the  bramic  acid.      Its  combinations  are 


58 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


termed  bromides  ;  they  have  not  hitherto 
heen  applied  to  any  use,  hut  some  of 
them  are  probably  possessed  of  powerful 
medical  qualities. 

In  this  country  bromine  is  obtained 
from  the  mother  waters  of  the  Salt 
Springs  in  the  Valley  of  the  Mississippi. 
Its  chief  use  is  in  daguerreotyping,  as  an 
accelerator,  to  coat  the  silver  plate,  and 
aid  the  iodine  in  producing  the  image  in 
a  shorter  period. 

BRONZE.  A  material  used  for  casting 
statues,  groups,  &c,  in  a  mould  similar 
in  principle  to  that  wherefrom  all  plaster 
casts  are  produced.  From  the  extraordi- 
nary dimensions  which  involve  the  chief 
differences  between  the  operations  of  cast- 
ing in  brass  and  plaster,  much  intelligence 
and  care  on  the  part  of  the  sculptor  is 
necessary  to  produce  the  fac-simile  of  the 
work  on  which  his  labor  has  been  expen- 
ded. The  material  employed  for  the  pur- 
pose is  a  compound  chiefly  consisting  of 
copper^  tin,  and  other  metals.  The  pro- 
cess ot  procuring  the  cast  depends  on 
circumstances  requiring  much  nice  ar- 
rangement. 

Bronze  is  a  compound  metal,  consisting 
of  copper  and  tin,  to  which  sometimes  a 
little  zinc  and  lead  are  added.  The  alloy 
is  much  harder  than  copper,  and  was  cm- 
ployed  by  the  ancients  to  make  swords, 
hatchets,  &c,  before  the  method  of  ma- 
king iron  was  understood.  The  art  of 
casting  bronze  statues  may  be  traced  to 
the  most  remote  antiquity:  but  it  was 
first  brought  to  a  certain  degree  of  re- 
finement by  Theodorus  and  Roocus  of 
Samoa  about  700  years  before  the  Chris- 
tian era,  to  whom  the  invention  of  model- 
ling is  ascribed  by  Pliny.  The  ancients 
were  well  aware,  that  by  combining  cop- 
per with  tin  a  more  fusible  metal  was 
obtained,  that  the  process  of  easting  was 
therefore  rendered  easier,  and  that  the 
statue  was  harder  and  more  durable;  and 
yet  they  frequently  made  them  of  cop- 
per nearly  pure,  because  they  possessed 
no  means  of  determining  the  proportions 
of  their  alloy,  and  because  by  their  mode 
of  managing  the  fire,  the  copper  became 
refined  in  the  course  of  melting,  as  has 
happened  to  many  founders  in  our  own 
days.  It  Avas  during  the  reign  of  Alex- 
ander that  bronze  statuary  received  its 
greatest  extension,  when  the  celebrated 
artists  Lysippus  succeeded  by  new  pro- 
cesses of  moulding  and  melting  to  multi- 
ply groups  of  statues  to  such  a  degree 
that  Pliny  called  them  the  mob  of  Alex- 
ander. Soon  afterwards  enormous  bronze 
colossuses  were  made  to  the  height  of 


towers,  of  which  the  isle  of  Rhodes  pos- 
sessed no  less  than  one  hundred. 

The  Roman  consul  Mutianus  found 
3,000  bronze  statues  at  Athens,  3,000  at 
Rhodes,  as  many  at  Olympia  and  at  Del- 
phi, although  a  great  number  had  been 
previously  carried  off  from  the  last  town. 

In  forming  such  statues  the  alloy  should 
be  capable  of  flowing  readily  into  all  the 
parts  of  the  mould,  however  minute  ;  it 
should  be  hard,  in  order  to  resist  acci- 
dental blows,  be  proof  against  the  influ- 
ence of  the  weather,  and  be  of  such  a  na- 
ture as  to  acquire  that  greenish  oxidized 
coat  upon  the  surface  which  is  so  much 
admired  in  the  antique  bronze.  The 
chemical  composition  of  the  bronze  alloy 
is  a  matter  therefore  of  the  first  moment. 
The  brothers  Keller,  celebrated  founders 
in  the  time  of  Louis  the  Fourteenth, 
whose  chefs  cPceuvre  are  well  known,  di- 
rected their  attention  towards  this  point, 
to  which  too  little  importance  is  attached 
at  the  present  day.  The  statue  of  Desaix, 
in  the  Place  Vendome  in  Paris,  is  a  noted 
specimen  of  most  defective  workman- 
ship from  mismanagement  of  the  alloy3 
of  which  it  is  composed. 

On  analyzing  separately  specimens  ta- 
ken from  the  bas-reliefs  of  the  pedestal 
of  this  column,  from  the  shaft,  and  from 
the  capital,  it  was  found  that  the  first 
contained  only  6  per  cent,  of  the  alloy, 
and  94  of  copper,  the  second  much  less, 
and  the  third  only  0-21.  It  was  there- 
fore obvious  that  the  founder,  unskilful 
in  the  melting  of  bronze,  had  gone  on 
progressively  refining  his  alloy  by  the 
oxidizement  of  the  tin,  till  he  had  ex- 
hausted the  copper,  and  that  he  had  then 
worked  up  the  scoria  in  the  upper  part  of 
the  column.  The  moulding  ot  the  seve- 
ral bas-reliefs  was  so  ill-executed  that  the 
chisellers  employed  to  repair  the  faults, 
removed  no  less  than  70  tons  of  bronze, 
which  was  given  them,  besides  300,000 
francs  for  their  work. 

The  alloy  most  proper  for  bronze  med- 
als, which  are  to  be  afterwards  struck,  is 
composed  of  from  8  to  12  parts  of  tin, 
and  from  92  to  88  of  copper;  to  which  if 
2  or  3  parts  in  the  hundred  of  zinc  be 
added,  they  •will  make  it  assume  a  finer 
bronze  tint.  The  medal  should  be  sub- 
jected to  three  or  four  successive  stamps 
of  the  press,  and  be  softened  between 
each  blow  by  being  heated  and  plunged 
in  cold  water. 

Bell-Metal.  The  bronze  of  bells,  or  bell 
metal,  is  composed  in  100  parts  of  78  cop- 
per and22  tin.  This  alloy  has  a  fine  com- 
pact grain ;  is  very  fusible  and  sonorous. 


BRO] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


59 


The  other  metals  sometimes  added  are  ra- 
ther prejudicial,  and  merely  increase  the 
profit  of  the  founders.  Some  of  the  Eng- 
lish bells  consist  of  80  copper,  10-1  tin,  5-6 
zinc,  and 4-3  lead;  the  latter  metal,  when 
in  such  large  quantity,  is  apt  to  cause  in- 
sulated drops,  hurtful  to  the  uniformity 
of  the  alloy.  A  little  phosphorus  is  some- 
times added  with  advantage. 

The  Chinese  gongs  are  composed  of  78 
parts  copper,  and  22  parts  tin.  This  alloy 
when  newly  cast  is  as  brittle  as  glass,  but 
by  being  plunged  at  a  cherry-red  heat 
into  cold  water,  and  confined  between 
two  discs  of  iron  to  keep  it  in  shape,  it 
becomes  tough  and  malleable.  The  Chi- 
nese cymbals  consist  of  80  parts  copper 
and  20  parts  tin. 

Common  Metal  consists  of  about  90  or 
91  copper,  and  9  or  10  of  tin.  Never  less 
than  8  or  more  than  11  parts  of  tin  in  the 
100  should  be  employed. 

Speculum  Metal.  One  part  of  tin  and 
two  parts  (or  more  exactly  100  parts  tin 
and  215  parts  copper)  form  the  ordinary 
speculum  metal  of  reflecting  telescopes, 
which  is  of  all  the  alloys  the  whitest,  the 
most  brilliant,  the  hardest,  and  the  most 
brittle.  The  alloy  of  1  part  tin  and  10  of 
copper,  is  the  strongest  of  the  whole  series. 

The  bronze  founder  ought  to  melt  his 
metals  rapidly,  in  order  to  prevent  the 
loss  of  tin,  zinc,  and  lead,  by  their  oxi- 
dizement.  Keverberatory  furnaces  have 
been  long  used  for  this  operation,  the 
best  being  of  an  elliptical  form.  The  fur- 
naces with  dome  tops  are  employed  by 
bell  founders,  because  their  alloy  being 
more  fusible,  they  do  not  require  so  in- 
tense a  heat ;  but  they  also  would  find  an 
advantage  in  using  a  more  rapid  mode  of 
fusion.  The  surface  of  the  melting  met- 
als should  be  covered  with-  small  charcoal 
or  coke,  and  when  the  zinc  is  added  it 
should  be  dexterously  thrust  to  the  bot- 
tom of  the  melted  copper.  Immediate!  y 
after  stirring  the  melted  mass  so  as  to  in- 
corporate the  ingredients,  it  should  be 
poured  out  into  the  moulds.  In  general 
the  metals  most  easily  altered  by  the  fire, 
as  the  tin,  should  be  put  in  last.  The 
coating  should  be  as  quick  as  possible  in 
the  moulds  to  prevent  the  metals  separa- 
ting from  each  other  in  the  order  of  their 
destiny,  as  they  are  very  apt  to  do  so. 
The  addition  of  a  little  iron  in  the  form  of 
tin-plate,  to  bronze  is  reckoned  to  be  ad- 
vantageous. 

Bronzing  (of  Objects  in  Imitation,  of 
Metallic  Bronze),  blaster  of  Paris,  paper, 
wood,  and  pasteboard,  may  be  made  to 
resemble  pretty  closely  the  appearance  of 


articles  of  real  bronze,  modern  or  an- 
tique. The  simplest  way  of  giving  a 
brilliant  aspect  ot  this  kind  is  with  a  var- 
nish made  of  the  waste  gold  leaf  of  the 
beater,  ground  up  on  a  porphyry  slab 
with  honey  or  gum-water.  A  coat  of 
drying  linseed-oil  should  be  first  ap- 
plied, and  then  the  metallic  powder  put 
on  with  a  linen   dossil.      Mosaic    gold 

? ground  up  with  six  parts  of  bone-ashes 
ms  been  used  in  the  same  way.  When 
it  is  to  be  put  on  paper,  it  should  be 
ground  up  alone  with  white  of  eggs  or 
spirit  varnish,  applied  with  a  brusn,  and 
burnished  when  dry.  When  a  plate  of 
iron  is  plunged  into  a  hot  solution  of  sul- 
phate of  copper,  it  throws  down  fine 
scales  of  copper,  which  being  repeatedly 
washed  with  water,  and  ground  along  with 
six  times  its  weight  of  bone-ashes,  forms 
a  tolerable  bronze. 

Powdered  and  sifted  tin  may  be  mixed 
with  a  clear  solution  of  isinglass,  applied 
with  a  brush,  and  burnished  or  not,  ac- 
cording as  a  bright  or  dead  surface  is  de- 
sired. '  Gypsum  casts  are  commonly  bron- 
zed by  rubbing  brilliant  black-lead,  gra- 
phite,  upon  them  with  a  cloth  or  brush. 
Keal  bronze  long  exposed  to  the  air  gets 
covered  with  a  thin  film  of  carbonate  of 
copper,  called  by  virtuosi  antique  cerugo 
(patine  antique,  Fr).  This  maybe  imita- 
ted in  a  certain  degree  by  several  appli- 
cations skilfully  made.  The  new  bronze 
being  turned  or  filed  into  a  bright  surface, 
and  rubbed  over  with  dilute  acquafortis 
by  a  linen  rag  or  brush,  will  become  at 
first  grayish,  and  afterwards  take  a  green- 
ish blue" tint;  or  we  may  pass  repeatedly 
over  the  surface  a  liquor  composed  of  1 
part  sal  ammoniac,  three  parts  of  carbo- 
nate of  potash,  and  6  or  sea  salt,  dis- 
solved in  12  parts  of  boiling  water,  to 
which  8  parts  of  nitrate  of  copper  are  to 
be  added;  the  tint  thereby  produced  is 
at  first  unequal  and  crude,  but  it  becomes 
more  uniform  and  softer  by  time.  A  fine 
green-blue  bronze  may  be  obtained  with 
very  strong  water  of  ammonia  alone,  rub- 
bing it  at  intervals  several  times  upon  the 
metal. 

The  base  of  most  of  the  secret  compo- 
sitions for  giving  the  antique  appearance 
is  vinegar  with  sal  ammoniac.    Skilful 
workmen  use  a  solution  of  2  ounces  of 
that  salt  in  an  English  quart  of  French 
vinegar.   Another  compound  which  gives 
good  results  is   made  with  an  ounce  of 
sal  ammoniac,  and  a  quarter  of  an  ounce 
I  of  salt  of  sorrel  (binoxalate  of  potash),  dis- 
|  solved  in  vinegar.     One  eminent  Parisian 
I  sculptor  makes  use  of  a  mixture  of  half  an 


60 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[but 


ounce  of  sal  ammoniac,  half  an  ounce  of 
salt,  an  ounce  of  spirits  of  hartshorn,  and 
an  English  quart  of  vinegar.  A  good  re- 
Bult  will  also  be  obtained  by  adding  half 
an  ounce  of  sal  ammoniac,  instead  of  the 
spirits  of  hartshorn.  The  piece  of  metal 
being  well  cleaned,  is  to  be  rubbed  with 
one  of  these  solutions,  and  then  dried  by 
friction  with  a  fresh  brush.  If  the  hue 
be  found  too  pale  at  the  end  of  two  or 
three  days,  the  operation  may  be  repeated. 
It  is  found  to  be  more  advantageous  to 
operate  in  the  sunshine  than  in  the  shade. 

In  bronzing  plaster  figures  a  cement 
may  be  used  or  not ;  if  used,  the  bronz- 
ing will  be  more  durable,  the  powders 
are  mixed  with  strong  gum  water  or  isin- 
glass, and  laid  on  with  a  pencil.  The  sub- 
ject may  be  covered  with  gold-size  dilu- 
ted with  turpentine,  and  when  nearly 
dry  rubbed  with  a  piece  of  soft  leather. 

Coins  of  copper  and  medals  may  be 
bronzed  thus  : — Dissolve  in  vinegar  2 
parts  of  verdigris  and  1  part  sal  ammoniac. 
Boil,  shim,  and  dilute  the  solution  with 
water  until  it  ceases  to  let  fall  a  white 
precipitate.  The  solution  is  then  boiled 
and  poured  upon  the  objects  to  be  bron- 
zed, previously  made  perfectly  clean  and 
free  from  grease,  the  articles  are  then 
washed  and  dried. 

A  deposit  of  brass  or  bronze  may  be 
thrown  on  objects  by  the  electrotype  pro- 
cess, by  employing  a  solution  of  500  parts 
carbonate  of  potash,  20  parts  chloride  of 
copper,  40  parts  sulphate  zinc,  250  parts 
nitrate  of  ammonia. 

For  bronzing,  a  salt  of  tin  is  substitu- 
ted for  the  zinc  salt.  By  this  solution, 
iron,  cast  iron  steel,  lead,  zinc,  tin  or 
their  alloys  are  easily,  coated  with  brass  or 
bronze,  by  placing  the  article  in  contact 
with  the  negative  pole  of  a  Bunsen  bat- 
tery, and  a  plate  of  bronze  or  brass  used 
as  a  positive  pole. 

BRUNSWICK  GREEN.  A  pigment 
obtained  by  exposing  metallic  copper  to 
the  action  of  muriate  of  ammonia.  It  is 
a  compound  of  chloride  and  oxide  of  cop- 
per. It  is  also  generated  by  the  action 
of  sea  water  upon  copper,  as  'in  the  green 
matter  which  incrusts  the  copper  sheath- 
ing of  ships. 

BUDE  LIGHT.    (See  Gas). 

BURETTE.  An  instrument  occasion- 
ally used  in  the  chemical  laboratory,  and 
in  the  assay  office,  for  the  purpose  of 
dividing  a  given  portion  of  any  liquid 
into  100  or  1000  equal  parts. 

BUOYS.  Vessels  formed  of  wood, 
cork,  or  some  light  substance,  moored  or 
anchored  so  as  to  float  over  a  certain 


spot,  in  order  to  indicate  the  situation  of 
a  shoal  or  sand-bank,  and  mark  out  the 
course  a  ship  is  to  follow.  When  used 
for  this  purpose,  buoys  are  usually  close 
vessels  in  the  form  of  a  cone,  of  large 
dimensions,  in  order  that  they  may  be 
seen  from  a  distance  ;  and  generally 
painted  of  some  particular  color,  in  order 
that  they  may  be  more  readily  distin- 
guished from  one  another.  Private  buoys 
are  used  for  the  purpose  of  indicating 
the  situation  of  ships'  anchors  (to  which 
they  are  fastened  by  a  rope),  in  order 
that  the  ship  may  be  prevented  from 
running  foid  of  the  anchor,  and  that  the 
anchor  and  cable  may  be  recovered  when 
the  latter  happens  to  be  broken,  or  has 
been  cut. 

BUTTER.  The  oil  or  fat  of  milk.  The 
light  matters  suspended  in  milk  separate 
in  the  form  of  cream,  and  this  cream  by 
churning  becomes  separated  into  butter 
and  buttermilk.  During  this  process  the 
temperature  of  the  cream  is  slightly 
raised,  a  little  oxygen  absorbed,  and  the 
acid  produced :  this  change  is  not,  how- 
ever, essential  to  the  separation  of  the 
butter  which  takes  place  when  air  is  ex- 
cluded and  depends  upon  tho  rupture  of 
the  oil  globules.  It  is  naturally  of  a  yel- 
low color,  and  is  deepened  when  cows 
are  fed  in  rich  pastures  ;  and  carrot  juice 
and  arnotto  are  often  added  to  heighten 
the  tint.  The  Tartars  and  French  pre- 
serve butter  by  melting  it  in  a  water  bath 
at  a  temperature  of  176°,  whereby  the  al- 
buminous and  curdy  matters,  which  are 
putrescible,  are  coagulated.  If  it  be  de- 
canted while  liquid,  strained  and  lightly 
salted,  it  may  be  kept  fresh  for  years. 

In  November,  1849,  a  patent  was  grant- 
ed to  Mr.  Elias  H.  Merryman,  of  Spring- 
field, Illinois,  for  improvements  in  But- 
ter-working Machines.  His  claim  is  the 
use  of  two  or  more  rollers,  with  adjusta- 
ble scrapers,  held  in  contact  with  the 
rollers  by^  springs,  or  other  devices, 
operating  in  a  vat  of  running  water,  to 
wash  butter  and  separate  the  broken 
capsules,  cheesy  matter,  buttermilk,  and 
other  impurities,  by  dissolving  thost 
that  are  soluble  in  water,  and  washing 
away  those  that  are  not  soluble,  sub 
stantially  as  described — the  water  bcina 
let  into  the  vat  from  a  cistern  placed 
above  the  level  of  the  vat,  and  escaping 
at  the  spout,  on  a  level  with  the  journals 
of  the  rollers. 

According  to  the  census  return  of  1845, 
the  quantity  of  butter  mode  in  the  State 
of  New-York,  was  79,501,770  pounds; 
which  at  twelve  and  a  half  cents  a  pound, 


but] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


61 


would  amount  to  $9,937,716.  American 
butter,  if  well  prepared,  would  find  a 
leady  sale  in  the  English  market. 

The  following,  taken  from  the  Patent- 
Office  Reports  of  1847,  is  the  plan,  in 
substance,  pursued  by  Philip  Physick  of 
Germantown,  who  has  taken  the  pre- 
mium of  the  Philadelphia  Agricultural 
Society  for  two  or  three  years  succes- 
sively. In  the  first  place,  great  atten- 
tion is  paid  to  cleanliness  :  the  tin  pans 
are  put  into  a  boiler  and  boiled  for  an 
hour,  then  scoured  with  white  silver- 
sand  and  pure  hard  soap  and  rinsed  in 
pure  water,  and  then  put  away  for  use. 
The  udders  of  the  cows  are  washed  for 
three  days,  and  wiped  with  a  clean  towel. 
The  milk  is  also  drawn  in  tin  pails,  which 
have  been  cleansed  in  the  same  manner 
as  the  pans  ;  it  is  strained  through  a  per- 
fectly clean  muslin  strainer,  and  put  into 
the  spring-house  till  four  milkings  are 
collected ;  then  *he  whole  milk  and  cream 
are  thrown  into  a  common  barrel-churn, 
which  has  been  rinsed  with  boiling  wa- 
ter with  a  quarter  of  a  peck  of  hickory 
ashes  and  live  coals  stirred  about  in  it 
by  turning  the  crank,  and  then  thrown 
out  and  the  churn  rinsed  several  times 
with  boiling  water  ;  the  cows'  udders 
are  then  washed  and  milked,  and  this 
milk  strained  and  poured  warm  into  the 
churn — the  churning  is  done  slowly,  as 
the  tenacity  and  hardness  of  the  butter 
depends  on  this;  it  should  take  three 
hours.  When  the  butter  has  come  it  is 
collected  by  a  clean  wooden  ladle  and  laid 
on  a  clean  linen  cloth  as  flat  as  possible, 
not  more  than  two  inches  thick.  Next 
take  a  clean  coarse  cotton  bag,  which  will 
hold  a  half  peck  or  more,  and  fill  it  with 
ice,  and  with  a  mallet  mash  it  down  flat 
about  four  inches  thick  ;  place  the  cloth 
on  it  till  it  is  hard ;  then  on  a  clean  white 
marble  slab  add  finely  pulverized  salt  to 
suit  the  taste,  and  work  out  the  butter- 
milk with  a  wooden  spoon  and  ladle; 
spread  the  butter  flat  again,  and  again 
sopping  up  the  buttermilk  with  the  linen 
cloth,  which  must  however,  be  done  very 
slowly.  When  it  is  free  from  all  the  but- 
termilk, make  it  up  into  pounds  or  half 
pounds. 

BUTTONS.  .The  materials  of  which 
buttons  are  made  are  very  various,  and 
this  variety  gives  rise  to  a  subdivision 
somewhat  akin  to  that  which  marks 
many  other  departments  of  manufac- 
tures. Besides  the  well  known  gilt  but- 
tons, plain  and  figured,  there  are  plated, 
silk,  florentine,  and  other  covered  but- 
tons—pearl,   horn,   shell,   bone,   wood, 


glass,  and  porcelain  buttons,  and  proba- 
bly many  others.  The  two  latter-named 
varieties  are  made  at  the  works  where 
cither  glass  or  porcelain  articles  are  ma- 
nufactured ;  but  the  rest  are  produced 
chiefly  at  Birmingham,  the  different  ma- 
nufacturers producing  their  respective 
varieties. 

The  number  of  females  to  which  the 
manufacture  gives  employment  is  very 
large,  and  the  nimbleness  with  which 
most  of  the  processes  are  carried  on  by 
them  is  truly  remarkable. 

We  may  first  select  a  common  gilt 
button,  and  follow  it  through  its  pro- 
cesses of  manufacture.  The'material  of 
which  these  are  made  is  sheet  copper,  or  a 
mixed  metal  of  which  copper  is  a  compo- 
nent part.  From  these  sheets,  "blanks" 
or  circular  pieces  are  cut  out,  a  trifling 
degree  larger  than  the  intended  size  of 
the  button.  This  is  done  by  means  of 
small  presses,  of  which  there  is  a  large 
number  in  every  factory,  devoted  to  one 
or  other  of  the  different  kinds  of  button. 
The  press  for  cutting  the  "blanks"  ha3 
a  circular '  cutter  or  punch,  worked  by  a 
lever  or  handle ;  and  a  female  holding  a 
sheet  of  metal  in  one  hand  and  the  lever 
of  the  press  in  the  other,  cuts  the  blanks 
with  surprising  rapidity,  shifting  the 
copper  after  each  cut  in  order  to  expose 
a  new  part  of  the  surface,  and  causing 
the  punch  to  descend  after  each  adjust- 
ment. 

Whatever  be  the  form  or  nature  of  the 
button,  this  preliminary  punching  of  the 
blank  is  almost  always  observed;  but 
beyond  this,  many  varieties  occur.  The 
common  flat  gilt  buttons  for  coats  are  flat 
on  both  sides,  and  consist  of  but  one 
thickness  of  metal,  which  is  punched  out 
in  the  form  of  a  blank.  But  there  are 
many  kinds  of  livery  buttons,  small  glo- 
bular buttons  for  boys'  dresses,  and  other 
kinds,  which  are  convex  on  the  outer 
surface ;  and  this  convexity  has  to  be 
given  to  them  after  the  blawk  is  cut. 
Again,  of  those  which  are  convex,  some 
are  of  one  thickness  only,  presenting  at 
the  back  the  concave  side  of  the  same 
piece  of  metal  which  is  convex  in  front ; 
while  others  (called  "shell"  buttons) 
are  hollow,  and  made  of  two  pieces  of 
metal — one  for  the  front  and  the  other  for 
the  back.  In  this  latter  case,  there  are 
two  blanks  or  circular  pieces  punched 
out  separately ;  one  called  the  "  shell," 
and  the  other  the  "  bottom."  The  shell, 
as  well  as  convex  buttons  generally,  is 
pressed  to  a  convex  shape  by  a  machine 
similar   in    principle    to    the    punching 


62 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[but 


press,  but  having  a  curved  polished  sur- 
face to  act  upon  the  metal,  instead  of  a 
punch.  One  female  will  stamp  twelve 
gross  in  an  hour,  or  nearly  thirty  per 
minute. 

The  rawness  of  the  edge  is  removed 
by  turning  each  button  slightly  in  a  lathe, 
to  give  regularity  of  surface. 


To  bring  both  parts  of  the  shell  button 
together,  they  are  pressed  in  a  die  and 
punch,  so  peculiarly  adjusted  that  the 
edge  of  the  shell  becomes  bent  over  and 
lapped  down  upon  the  bottom,  securing 
the  two  together  in  a  way  at  once  firm 
and  neat  without  the  employment  of  any 
solder,  rivet,  or  other  mode  of  fastening. 
The  device,  or  letters  on  buttons,  is  given 
by  steel  dies,  and  a  stamping  press  simi- 
lar in  construction  with  the  wood-cut. 

The  shank  of  a  button  is  in  some  re- 
spects more  remarkable  even  than  the 
blank,  partly  on  account  of  its  manufac- 
turing arrangements  —  strange  as  they 
will  appear  to  most  persons.  It  might 
well  be  supposed  that  in  large  factories 
where  five  or  six  hundred  persons  are 
employed  in  making  buttons,  the  pro- 
duction of  the  bit  of  twisted  wire  which 
forms  the  shank,  would  at  least  form  one 
of  the  departments.  Yet  this  is  not  the 
case :  the  button-makers  are  not  shank- 
makers  ;  the  latter  branch  being  carried 
on  by  a  \>  holly  distinct  class  of  manufac- 
turers, of  whom  there  are  three  or  four 
in  Birmingham.  The  reason  seems  to 
be,  that  the  machinery  employed  is  so 
costly  and  intricate,  and  the  value  of  each 
shank  when  made  so  extrcmelv  minute, 
that  nothing  less  than  making  for  a  great 
many  button-makers  could  pay  for  the 
maintenance  of  a  regular  establishment ; 


so  that  the  button-makers,  as  a  body,  can 
buy  the  shanks  cheaper  than  make  them, 

Thus  does  the  commerce  of  manufac- 
tures adjust  and  regulate  itself,  when  left 
to  seek  its  natural  channels.  The  shanks 
are  made  of  brass  wire,  and  vary  from 
eight  to  forty  gross  per  pound  weight. 
In  the  beautiful  machine  now  employed 
for  their  manufacture,  a  coil  of  wire  is  so 
placed  that  one  end  gradually  advances 
towards  a  point  where  a  pair  of  shears 
cut  off  a  short  piece ;  a  stud  then  presses 
against  the  middle  of  the  piece,  and 
forces  it  between  the  two  jaws  of  a  kind 
of  vice  in  a  staple-like  form ;  the  jaws 
then  compress  it  so  as  to  form  the  eye  of 
the  shank ;  a  little  hammer  next  strikes 
the  end  to  make  it  level ;  and  lastly,  an- 
other movement  enables  the  shank  to 
drop  into  a  box  quite  ready  for  use. 
Some  English  firms  manufacture  two 
hundred  million  shanks  per  year. 

The  blanks  or  body  of  the  buttons  be- 
ing ready  to  receive  the  shank,  they  are 
handed  over  to  workwomen  who  'con- 
nect them.  The  button  is  laid  flat,  bot- 
tom upwards  ;  the  woman  places  the 
shank  in  the  proper  position  with  a  piece 
of  bent  iron,  like  a  spring  clasp ;  she 
presses  the  shank  tightly  to  the  bottom, 
touching  then  the  foot  of  the  shank  where 
it  joins  the  bottom,  with  a  little  solder. 
When  some  hundreds  are  so  adjusted,  the 
whole  are  placed  on  an  iron  plate  and  ex- 
posed on  an  oven  to  a  heat  sufficient  to 
melt  the  solder  and  unite  the  shank 
firmly  to  the  button. 

To  cleanse  the  buttons,  they  arc  dipped 
twice  in  nitric  acid,  and  let  drain.  To  be 
silvered  they  are  put  in  an  earthen  pan, 
containing  a  nearly  dry  mixture  of  silver, 
common  salt,  cream  tartar,  and  some 
other  ingredients,  and  well  stirred  up  for 
a  minute  or  two.  This  gives  them  a  sil- 
ver white  color.  The  gilding  is  a 
more  elaborate  process,  in  some  cases 
the  gilding  is  only  applied  to  the  face,  01 
top  gilding  ;  in  others,  to  the  whole  sur- 
face, called  all-over  gilding.  For  the  lat- 
ter purpose  the  buttons  are  first  pickled 
in  dilute  sulphuric  acid,  and  then  im- 
mersed in  a  solution  of  nitrate  of  mer- 
cury, which  leaves  a  thin  mercurial  de- 
posit over  the  whole  surface.  For  top- 
gilding,  the  tops  are  laid  on  a  board,  and 
washed  over  with  a  brush.  Five  grains  ot 
gold  will  cover  144  one-inch  buttons,  and 
sometimes  even  half  of  that  quantity  is 
made  to  serve.  A  few  grains  of  gold  leaf 
dissolved  in  ten  times  its  weight  of  mer- 
cury, is  the  amalgam  used  in  gilding. 
This  is  gently  heated  in  an  iron  ladle, 


cab] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


63 


and  stirred  with  an  iron  rod;  then 
poured  in  cold  water,  and  finally  strained 
through  wash  leather,  to  remove  the  su- 

Serfluous  mercury.  This  mass  is  then 
issolved  in  dilute  nitric  acid,  and  the 
buttons  either  dipped  in  or  washed  with 
it.  The  next  process  is  to  drive  off  the 
mercury  by  heat.  This  is  done  by  plac- 
ing the  buttons  in  a  wire  cage,  within  a 
furnace,  framed  to  carry  up  and  condense 


the  mercurial  vapors,  and  passing  them 
into  a  vessel  of  water,  to  polish  them. 
They  are  now  removed  to  the  lathe,  and 
carefully  burnished  with  bloodstone. 

The  ilorentine  and  silk  buttons  have 
now  nearly  superseded  the  gilt  button 
manufacture.  These  contain  each  two 
circular  bits  of  iron,  a  piece  of  thick 
pasteboard,  another  of  canvas,  and  the 
outer  silk  or  florentine  covering.  All 
these  are  cut  out  by  stamping  presses. 
The  sheet  of  iron,  of  paper,  of  canvas,  or 
of  Ilorentine,  is  shifted  gradually  till  it  is 
nearly  all  cut  up  into  little  discs'. 

The  mode  in  which  all  the  pieces  are 
fixed  together  is  very  remarkable.  There 
is  no  glue  or  cement,  no  riveting,  no  sew- 
ing, plaiting,  twisting,  or  other  modes  of 
fastening ;  'all  being  adjusted  and  fixed 
simply  by  stamping  or  pressure.  With- 
in tne  outer  cloth  cover  is  an  iron  casing 
called  the  '  shell,'  within  this  is  a  disc  of 

Eaper,  then  a  disc  of  cloth,  and  at  the 
ack  of  all  a  disc  of  iron  having  a  hole  in 
the  centre,  through  which  some  of  the 
canvas  is  forced  as  a  means  for  sewing  the 
button  on  the  coat  or  garment.  All  these 
are  placed,  in  their  proper  order,  in  a 
kind  of  die  or  cell,  and  a  descending 
punch,  worked  by  a  press,  first  fixes  the 
cover  to  the  shell,  and  then  these  two  to 


the  other  three  bits,  curling  up  the 
edges  of  the  two  discs  of  iron  in  such  a 
peculiar  way  as  to  enable  them  to  clasp 
all  the  five  bits  firmly,  and  to  hide  all 
raggedness  and  imperfections  of  edge. 
The  internal  mechanism  of  the  presses, 
to  effect  this,  is  beautiful  and  ingenious. 
Some  of  the  silk  buttons  have  the  iron 
'  shell '  blacked  with  japan  before  being 
used ;  some  are  convex,  while  others  are 
flat ;  some  have  a  woven  device  in  the 
centre  of  each,  obtained  by  having  the 
silk  or  other  material  woven  expressly 
for  the  purpose,  and  by  having  each  lit- 
tle disc  marked  out  carefully  by  a  separate 
apparatus  to  insure  accurate  punching ; 
some  have  braided  edges,  produced  by  an 
additional  number  of  pieces,  and  an  addi- 
tional complication  of  the  stamping  pro- 
cess ;  and,  indeed,  there  are  numerous  mo- 
difications of  the  covered  button  which  it 
would  be  difficult  to  particularize  here ; 
but  the  punching  out  of  separate  little 
discs,  and  the  fixing  of  these  by  stamping 
or  pressure,  are  the  prevailing  features 
of  the  manufacture  among  all. 

White  linen  buttons,  of  a  remarkably 
neat  appearance,  are  among  the  novelties 
of  recent  times.  They  consist  of  a  tin  or 
white  metal  ring,  over  which  a  disc  of 
linen  is  stretched  like  the  parchment  of  a 
tamborine ;  and  the  beautiful  manner  in 
which  the  two  are  fixed  together  by  a 
singular  action  of  the  press  is  very  strik- 
ing. The  buttons  made  of  bone,  of  horn, 
of  wood,  of  mother-of-pearl,  and  of  other 
materials,  are  generally  the  produce  of 
other  manufacturers,  who  work  out  their 
results  by  the  aid  of  the  circular  saw, 
the  lathe,  the  press,  and  a  few  other 
pieces  of  apparatus. 

CABLE.  The  rope  or  chain  by  which 
the  anchor  of  a  ship  is  held.  Cables,  un- 
til within  a  recent  period,  were  usually 
made  of  hemp,  but  of  late  years  iron 
chains  have  come  much  into  use.  A 
hempen  cable  of  12  inches  girth,  and 
length  120  fathoms,  weighs  3075  lbs. 
Since  the  weights  of  two  cables  of  equal 
lengths  will  be  as  their  sections,  or 
squares  of  their  girths,  it  is  easy  to  de- 
duce the  following  rule  for  the  weight  of 
any  hempen  cable  : — Multiply  the  square 
of  the  girth  in  inches  by  21-3"(or  21  near- 
ly enough),  the  product  is  the  weight 
in  lbs.  Since  also  as  the  breaking 
strain,  or  resistance  against  the  force  to 
part  the  cable,  will  be  as  the  section,  it 
will  be  as  the  weight,  and  will  be  found 
nearly  by  dividing  the  weight  in  lbs.  by 
100:  the  quotient  i~  the  breaking  strain 
in  tons.    This  rule  is  of  course  liable  to 


64 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CAL 


great  uncertainty  from  the  quality  or 
wear  of  the  cable.  Chain  cables  possess 
great  advantages  over  hempen  cables ; 
they  are  not  liable  to  be  destroyed  by 
chafing  on  rocky  grounds,  nor  to  become 
rotten  and  insecure  from  alternate  expo- 
sure to  the  air  and  water ;  and  by  reason 
of  their  greater  weight  the  strain  is  ex- 
erted on  the  cable  rather  than  on  the 
ship.  In  order  that  the  ship  may  be  en- 
abled to  let  slip  her  cable  in  case  of  neces- 
sity, chain  cables  are  furnished  with 
bolts  at  distances  from  each  other  of  a 
fathom  or  two,  which  can  be  readily  with- 
drawn. A  chain  of  which  the  section  is 
1  inch  in  diameter  breaks  with  16  tons  ; 
such  a  chain  is  equivalent  to  a  10  inch 
hemp  cable  nearly.  And  the  dimensions 
of  the  chain  cable  corresponding  to  any 
hemp  cable  are  therefore  easily  found  by 
merely  dividing  the  circumference  of  the 
hemp  cable  by  10.  The  strength  of  every 
part  of  the  chain  is  proved  before  it 
leaves  the  manufactory. 

CADMIUM.  A  white  metal,  much 
like  tin.  It  fuses  and  volatilizes  at  a 
temperature  a  little  below  that  at  which 
tin  melts.  Specific  gravity  about  9.  Its 
ores  are  associated  with  those  of  zinc. 
It  was  discovered  in  1818  by  Professor 
Stromeyer  of  Gottingen.  Its  equivalent 
number  is  56.  It  forms  a  yellow  sali- 
fiable oxide  eomposed  of  56  cadmium+8 
oxygen=64  oxide  of  cadmium.  Its  scarci- 
ty prevents  its  employment  in  the  arts, 
but  the  oxide  has  been  used  as  a  pig- 
ment, and  the  metal  has  been  used  in 
stopping  teeth. 

CAFFEINE.  A  bitter  crystalline  sub- 
stance contained  in  coffee.  It  is  volatile, 
and  part  of  it  is  lost  in  roasting  the  berry. 
It  is  also  found  in  tea,  and  in  the  ilex 
guaranensis  of  Brazil.  It  has  not  been 
applied  in  the  arts  to  any  useful  purpose. 

CAISSON.  In  architecture,  a  sunken 
panel  in  a  flat  or  vaulted  ceiling,  or  in  the 
soffit  of  a  cornice.  In  ceilings  they  are 
of  various  geometrical  forms,  and  often 
enriched  with  rosettes  or  other  orna- 
ments. Caisson,  in  bridge  building,  is  a 
large  chest  or  vessel  in  which  the  piers 
of  a  bridge  are  bnilt.  This  sinking  as 
the  work  advances,  its  bottom  at  last 
comes  in  contact  with  the  bed  of  the  ri- 
ver, when  the  sides  are  disengaged,  its 
construction  being  such  as  to  admit  of 
their  being  thus  detached  without  injury 
to  the  floor  or  bottom. 

CALAMINE.  Native  carbonate  of 
zinc. 

CALCINATION.  The  reduction  of 
substances  to  cinder  or  ash.   The  term  is 


derived  from  the  Latin  word  calx,  quick- 
lime, which,  as  is  well  known,  is  pre- 
pared by  the  action  of  heat  upon  lime- 
stone; and  hence  the  old  chemists  em- 
ploy the  word  calcination  to  express  any 
supposed  analogous  change,  metallic  sub- 
stances being  apparently  converted  into 
earthy  matter  by  calcination. 

CALCIUM.  The  metallic  base  of  lime, 
discovered  in  1808  by  Davy.  This  sub- 
stance has  hitherto  been  obtained  in  such 
small  quantities,  that  its  properties  have 
not  been  accurately  investigated.  It  is 
probably  a  brilliant  white  metal,  highly 
inflammable,  and  more  than  twice  as 
heavy  as  water.  Combined  with  oxygen 
it  forms  lime,  which  consists  of  20  cal- 
cium+8  oxygen=28  lime.     (See  Lime.) 

CALENDERING.  The  subjection  of 
cloth  and  other  articles  to  a  machine, 
which,  when  so  prepared,  are  calendered, 
literally  meaning  7iot-pressed ;  by  passing 
between  cylinders  or  rollers  it  acquires  a 
level  or  uniform  surface.  After  goods 
are  bleached  and  washed,  they  are  twisted 
and  tangled,  so  that  they  would  not  pass 
smoothly  between  the  cylinders.  Ihcy 
are  previously  passed  over  the  surface  of 
a  water-cistern,  and  reaching  the  rollers 
in  a  damp  state,  they  unfold  themselves 
readily.  The  first  pair  of  rollers  over 
which  the  cloth  is  passed,  does  not  dry 
or  quite  smooth  it.  The  rollers  in  the 
calender  are  fixed  in  a  vertical  series  in 
an  upright  frame,  the  rollers  being 
pressed  forcibly  together  by  lever  power. 
The  lower  rollers  are  generally  grooved 
to  remove  creases  ;  the"  upper  rollers  are 
smooth,  and  of  wood  and  brass.  In  pass- 
ing between  these  the  cloth  is  smoothed 
and  stretched,  when  it  is  wound  upon  a 
roller,  ready  to  be  starched. 

The  starch  is  made  from  flour,  fer- 
mented and  strained  to  separate  the  bran ; 
a  little  indigo  is  added  to  give  a  blue 
tint,  and  the  liquor  thickened  with  por- 
celain clay,  or  calcined  gypsum,  to  give 
apparent  strength  and  thickness  to  the 
cloth,  and  make  it  more  attractive  to  the 
purchaser.  The  starch  is  laid  on  by  a  stiff- 
ening mangle ;  the  cloth  first  passing  un- 
der a  roller  into  a  trough  containing  the 
starch-liquor,  becomes  filled  with  starch, 
and  then  carried  upwards,  passes  be- 
tween rollers  of  brass  and  wood,  tightly 
fitting  against  each  other,  by  which  the 
superfluous  starch  is  pressed  out,  and 
falls  down  into  the  trough  below.  The 
cloth  is  then  dried  by  being  passed  over 
tin  or  copper  cylinders,  heated  by  steam. 
Muslins  arc  merelv  stretched  on  long 
frames  to  dry.      T^ic  finish  for  cotton 


cal] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


65 


goods  is  generally  by  glazing^  which 
gives  a  bright  gloss  to  the  material.  In 
this  case  the  cloth  must  first  be  damped, 
which  is  done  by  passing  it  over  a  cylin- 
der, while  a  brush  is  at  the  same  time 
scattering  fine  spray  of  water  on  the  stuff. 
It  is  then  passed  between  the  rollers  of 
the  colors,  and  gets  a  silky  lustre. 

Copper-embossed  rollers  are  occasion- 
ally used  for  producing  figures  and  pat- 
terns on  velvet  goods.  After  the  cloth 
has  received  its  final  gloss,  it  is  smoothly 
folded  on  a  clean  board,  and  taken  to  be 
measured  preparatory  for  sale.  There 
are  upwards  of  one  hundred  ways  for 
making  up  goods.  Muslin  is  made  up 
in  book-folds,  in  pieces  of  24  yards ; 
usually  two  half  pieces  are  made  up  in  one 
book.  Cambrics  and  linens  are  in  pieces 
34  inches  wide,  and  8s  yards  long,  fold- 
ed up  small,  and  tightly  pressed.  Hand- 
kerchiefs are  sometimes  folded  in  dozens. 

CALICO  PKINTING.  The  art  of  pro- 
ducing figured  patterns  upon  cotton  by 
colored  substances.  Silk  and  woollen  fa- 
brics have  been  made  of  late  years,  sub- 
ject to  a  similar  style  of  dyeing.  The  fab- 
ric takes  its  name  from  Calicut,  a  district 
where  it  has  been  practised  for  many 
hundred  years.  The  art  of  Topical  dye- 
ing was  also  known  to  the  ancient  Egyp- 
tians. 

Before  cloth  can  receive  good  colored 
impressions,  it  must  be  freed  from  fibrous 
down  by  singing,  and  be  rendered  smooth 
by  the  calender.  They  are  next  bleached, 
except  those  intended  for  Turkey-red; 
after  being  bleached,  dried,  singed,  and 
calendered,  they  are  lapped  in  lengths  of 
several  pieces,  stitched  together. 


Four  different  modes  are  in  -jse  for 
printing  figures  upon  calico :  the  oldest 
is  by  wooden  blocks,  on  the  face  of  which 
the  design  is  cut,  which  are  worked  by 
hand.  The  wood-blocks  measure  about 
twelve  inches  by  seven.  They  have  a 
smooth  surface  of  sycamore  on  a  substra- 
tum of  some  commoner  kind  of  wood : 
and  the  design,  after  being  sketched  on 
the  block,  is  cut  as  in  common  wood-en- 
graving, the  parts  being  left  pi'ominent 
which  are  to  constitute  and  print  the  pat- 
tern. In  some  patterns,  where  there  are 
fine  lines,  the  wood  would  soon  be  worn 
away,  or  brought  to  a  defective  state  by 
use ;  and  to  obviate  this,  little  slips  of 
copper  are  inserted  into  delicate  grooves 
cut  for  them,  the  copper  slips  all  stand- 
ing at  an  equal  height,  and  forming  the 
printing  surface.  Small  pieces  of  felt 
are  in  some  places  introduced  to  fill  up 
the  instertices  between  the  coppers,  so  as 
to  imprint  a  broader  patch  of  color. 
One  block  can  only  print  one  color  : 
and,  therefore,  if  five  or  six  colors  form 
the  design,  and  all  be  printed  by  blocks, 
there  must  be  five  or  six  blocks,  all  equal 
in  size,  but  the  raised  parts  in  each  block 
corresponding  with  depressed  parts  in  all 
the  other  blocks.  The  principle  involved 
is  precisely  the  same  as  that  displayed  in 
floor-cloth  printing. 

Another  method,  quite  of  modern  in- 
troduction, is  somewhat  analogous  to 
stereotype  printing.  In  the  first  place  a 
model  is  formed  from  the  design,  com- 
prising so  much  of  it  as  may  be  included 
within  a  space  of  five  inches  long  bv  an 
inch  and  a  half  wide.  This  model  is 
formed  of  bits  of  metal  inserted  into  a 
ground  or  block,  and  a  mould 
is  produced  by  stamping  from 
the  model.  From  the  mould 
fixed  in  a  block,  and  adjusted 
in  a  convenient  way,  stereo- 
type pieces  or  copies  are  pro- 
duced, in  a  mixed  metal  of 
tin,  lead,  and  bismuth.  When 
a  number  of  these  pieces  are 
prepared,  their  surfaces  are 
brought  to  a  perfect  level  by 
means  of  a  file,  and  they  are 
then  firmly  fixed  down  upon 
a  stout  and  carefully  prepared 
piece  of  wood. 

The  block  -  printing  room 
generally  exhibits  a  number  of 
machines  similar  to  that  in 
the  cut. 

The  cloth  wound  off  rol- 
lers, passes  on  the  surface 
of  the  table  to  be  printed, 


66 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


fcAL 


and,  after  printing,  passes  on  to  another 
roller,  the  printer  regulating  this  move- 
ment. Each  machine  is  besides  attended 
by  a  boy  and  a  girl :  one  of  these  dips 
a  brush  into  the  color-vessel,  and  spreads 
a  layer  on  the  elastic  trough.  The  prin- 
ter takes  his  engraved  block  by  the  nan- 
die  on  its  back,  and  presses  it  on  the 
trough,  the  elasticity  of  which  allows 
every  part  of  the  raised  device  on  the 
block  to  take  up  a  layer  of  color,  and  then 
prints  a  portion  of  the  cloth  equal  to  the 
size  of  the  block.  There  are  small  pais 
or  guide-marks  on  the  corner  of  the 
block,  by  which  the  printer  is  enabled  to 
adjust  each  successive  impress  from  the 
block.  When  the  whole  piece  has  been 
worked  over  with  one  block,  the  printer 
goes  over  the  same  piece  with  a  second, 
perhaps  with  a  third,  and  so  on  according 
to  the  number  of  colors  in  the  design,  a 
new  block  being  used  for  every  color. 

Another  mode  of  printing  is  that  by 
which  all  the  colors  may  be  laid  on  at 
once  by  stereotype  plates.  A  flat  piece 
of  wood  is  provided  two  or  three  feet 
square,  on  which  are  fixed  all  the  stereo- 
type pieces ;  those  for  one  color  are 
ranged  in  one  row  or  stripe,  five  inches 
wide :  those  for  another  color  form  a  se- 
cond stripe,  contiguous  to  and  parallel 
with  the  first,  and  so  on  for  the  3d,  4th, 
or  5th.  The  length  of  each  stripe  is  equal 


to  the  breadth  of  the  cloth,  the  whole 
forming  a  compound  printing-block,  di- 
vided in  five  compartments.  These  block* 
are  used  in  a  printing-machine  similar  to 
type-printing:  the  block  is  fixed,  face 
downwards,  to  the  bottom  of  a  descend- 
ing frame,  capable  of  receiving  a  vertical 
motion,  and  the  cloth  being  laid  on  a  ta- 
ble beneath,  the  block  is  brought  down 
at  intervals  upon  it,  by  means  of  a  lever 
managed  by  the  pressman.  The  color  is 
laid  on  the  block  thus  : 

The  boy  has  five  troughs  of  color  (or 
more)  ranged  before  him;  with  a  long 
piece  of  wood  so  formed  as  to  dip  in  all 
these,  and  take  up  a  small  portion  from 
each,  he  dabs  it  on  a  flat  felt  cushion ; 
then  with  a  brush  he  spreads  these  five 
colors  in  an  equal  number  of  patches  over 
the  surface  of  the  felt,  without  combining 
or  smearing  one  over  the  other.  He  next 
slides  the  cushion  along  a  kind  of  railway 
till  it  comes  underneath  the  block,  which 
is  made  to  descend  upon  it,  and  to  imbibe 
a  layer  of  color  all  over  its  surface,  each 
one  of  the  five  rows  of  device  falling 
upon  one  particular  color  on  the  cushion, 
without  touching  the  others.  The  boy 
then  draws  out  the  cushion,  and  the  man 
guides  the  block  in  its  descent  upon  the 
cloth,  which  it  imprints  upon  five  differ- 
ent places  in  five  different  colors.  All 
this  is  repeated  a  second  time ;  but  be- 
fore the  wetted  block 
actually  descends, 
the  cloth  has  been 
made  to  shift  about 
five  inches  length- 
wise, or  equal  to  the 
width  of  one  row  of 
the  block.  By  this 
means  each  color  falls 
upon  a  part  which 
had  been  printed 
with  a  different  color 
in  the  former  de- 
scent. At  each  de- 
scent the  cloth  is 
shifted,  so  that  each 
portion  of  the  cloth 
is  brought  into  con- 
tact -with  each  of  the 
five  divisions  of  the 
block,  and  thus  re- 
ceives five  different 
colors. 

The  illustration 
serves  to  convey  an 
idea  of  this  which  is 
termed  press  print- 
ing. 


cal] 


CYCLOPEDIA    OP   THE   USEFUL   ARTS. 


67 


The  cylinder  printing  machine  con- 
sists of  an  engraved  copper  cylinder,  so 
mounted  as  to  revolve  against  another 
cylinder  lapped  in  woollen  cloth,  and 
imbued  with  a  colored  paste,  from  which 
it  derives  the  means  of  giving  colored 
impressions  to  pieces  of  cotton  passed 
over  it.  The  cylinder  as  it  rotates  dips 
in  a  long  trough  of  color,  and  every  part 
of  it  becomes  coated.  The  excess  of 
color  has  to  be  removed  from  the  sur- 
face of  the  cylinder  with  a  knife  :  this  is 
called  doctoring.  The  cloth  then  passes 
in  a  continuous  strip  between  the  cylin- 
der and  a  large  roller  or  drum  above,  by 
which  it  is  pressed  close  so  as  to  imbibe 
the  color  from  the  sunken  device  on  its 
surface.  As  the  cylinder  is  continually 
revolving  while  the    cloth   passes,   the 


printing  goes  on  uninterruptedly  with- 
out stoppage  or  break.  When  a  ma- 
chine prints  several  colors,  there  are  as 
many  cylinders  as  colors  required,  each 
having  a  trough  and  doctor  of  its  own, 
and  the  cloth  passes  in  contact  with  each 
in  turn. 

Each  cylinder  machine  prints  a  piece  (23 
yards)  of  cloth  in  a  minute  and  a  quarter, 
or  three  quarters  of  a  mile  per  hour.  In 
the  subjoined  illustration  the  cloth  may 
be  seen  traversing  the  cylinder. 

The  economy  of  cylinder  printing  is 
very  great.  One  machine  with  a  man, 
and  a  boy  to  tend  the  color  trough,  being 
capable  of  printing  as  many  pieces  as  200 
men  and  boys  could  do  with  blocks.  A 
modification  of  cylinder  printing  is  with 
wooden  rollers  cut  in  relief ;  it  is  called 
surface  printing,  the 
thick  color  being 
first  laid  on  a  tense 
woollen  surface,  and 
then  transferred  to 
the  cylinder.  When 
copper  and  wooden 
cylinders  are  com- 
bined in  one  appara- 
tus, it  has  gotten  the 
name  of  union  print- 
ing. Having  alluded 
to  the  mechanical 
operations,  those 
which  are  chemical 
require  now  to  be 
noticed. 

If  one  hundred 
patterns  of  cotton  re- 
quire to  be  printed, 
nearly  one  hundred 
different  modes  of 
proceeding  are  ne- 
cessary in  the  print- 
ing; for  not  only 
must  the  coloi-s  be 
different,  but  each 
color  may  perhaps 
require  a  peculiar 
groundwork  to  make 
it  adhere  to  the 
cloth.  Herein  lie  the 
delicacy  and  com- 
plexity of  the  calico- 
printer's  operations ; 
and  hence  arises  a 
different  chemical 
formula  for  almost 
every  different  pat- 
tern. Sometimes  a 
piece  of  cloth  is  par- 
tially printed,  then 
dyed,  and  then 
printed    again ;     at 


68 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[CAl 


other  times  the  printing  is  effected  at 
once  5  and  at  others  a  portion  of  the 
printing  is  to  lay  on  color  which  is  to  be 
afterwards  visible,  while  the  other  por- 
tion is  merely  to  imprint  the  cloth  with 
a  chemical  agent  which  shall  exert  some 
peculiar  effect  on  the  colors.  This  may 
perhaps  be  rendered  intelligible  by  al- 
luding to  four  different  kinds  of  liquids 
or  mixtures  which  are  printed  on  the 
cloth  by  means  of  the  cylinder,  the  press, 
or  the  block.  These  four  are  colors, 
mordants,  dischargers,  and  resists.  The 
name  colors  speaks  for  itself;  it  relates 
to  the  pigments  or  pastes  which  impart 
color  to  the  cloth,  and  includes  a  very 
wide  range  of  vegetable  and  mineral 
substances.  A  mordant  is  a  liquid  mix- 
ture which  enables  the  coloring  sub- 
stance to  combine  permanently  with  the 
textile  fibre  ;  and  this  is  used  when  the 
mordant  has  a  combining  affinity  with 
the  cloth  as  well  as  with  the  color,  al- 
though the  two  latter,  used  singly,  have 
no  affinity  for  each  other.  Thus,  if  a 
red  color  were  imparted  to  cloth  by  mad- 
der, it  would  wash  out,  or  not  be  a  "  fast 
Ofjlor;"  but  if  the  cloth  were  previously 
wetted  with  an  aluminous  salt,  the  mad- 
der color  would  be  permanent.  In  most 
cases  the  mordant  is  a  body  of  liquid, 
into  which  the  cloth  is  immersed ;  but 
sometimes  it  is  used  in  the  same  way  as 
a  paint  or  ink  by  the  cylinder-machine. 
Dischargers,  instead  of  being  intended  to 
fix  the 'color  to  the  cloth,  are  used  to 
drive  off  or  discharge  the  color  after  the 
latter  is  applied.  This  kind  of  chemical 
agent  is  used  in  combination  with  mor- 
dants, thus  :  the  cloth  is  wholly  satu- 
rated with  the  mordant,  but  certain  parts 
are  also  printed  with  a  discharger  formed 
cf  lemon-juice  or  some  other  substance  ; 
the  result  of  which  is,  that  when  the 
dye-color  is  afterwards  applied,  it  com- 
bines with  the  cloth  at  the  parts  where 
the  mordant  has  been  unaffected,  but 
becomes  a  "loose"  color  at  the  parts 
printed  with  the  discharger,  so  as  to  be 
easily  washed  out  from  those  parts.  Re- 
sists are  mixtures  which  enable  the 
printer  to  produce  white  portions  of  pat- 
tern by  a  process  rather  different  from 
the  discharge-method.  The  mordant  is 
printed,  not  dipped,  in  those  parts  which 
are  to  be  colored  in  the  pattern ;  while 
those  which  are  to  be  kept  white  are 
previously  printed  with  a  mixture  called 
a  resist  or  resist-paste.  The  cloth  is  then 
wholly  immersed  in  a  dye-vat,  but  those 
portions  which  had  been  printed  with 
the  resist  refuse  to  receive  the  dye,  and 


hence  remain  white.  It  will  be  seen, 
therefore,  that  in  "  discharge  work,"  as 
it  is  called,  the  white  portions  are  re- 
tained by  driving  out  the  mordant,  which 
would  otherwise  fix  the  color ;  while  in 
"  resist- work"  the  white  portions  are  re- 
tained by  shielding  the  cloth  at  those 
parts  from  the  action  of  the  color. 

In  calico  printing  it  is  necessary  to 
bring  the  mordant  or  the  color  into  that 
state  of  consistence  that  it  will  not 
spread  in  the  cloth  beyond  the  limit  of 
the  design.  The  usual  mordants  are 
alum  or  sulphate  of  alumina,  acetate  of 
alumina,  peroxide  of  iron,  protoxide  of 
tin,  and  oxide  of  chrome :  their  solu- 
tions are  made  of  the  proper  density  by 
thickeners,  such  as  wheat,  starch,  ancl 
flour ;  other  thickeners  are  used,  as  gum 
arabic,  British  gum,  gum  Senegal,  traga- 
canth,  jalap,  pipe  clay,  dextrine,  potato 
and  rice  starch,  sulphate  of  lead,  with 
gum,  sugar,  molasses,  and  glue.  These 
with  either  the  colon,  or  mordants  are 
prepared  in  vessels  furnished  with  steam 
jackets. 

The  manner  of  applying  a  pattern  on 
cloth  is  called  a  style :  of  these  there  are 
six. 

1.  The  madder  style. 

2.  Printing  by  steam. 

3.  The  padding  style. 

4.  The  resist  style. 

5.  The  discharge  style. 

6.  The  china  blue  style. 

The  madder  style  is  not  confined  to 
that  color,  but  the  process  is  applied  to 
many  others.  In  it  the  cotton  is  first 
printed  with  a  mordant  over  those  parts 
where  it  is  desired  to  have  a  color  pro- 
duced. When  the  mordant  has  been 
laid  on  by  the  cylinder  the  cloth  is  hung 
up  in  a  room  for  a  few  days,  when  the 
mordant  has  suffered  an  alteration  where- 
by it  becomes  insoluble,  and  fastened 
into  the  fibre  of  the  cloth.  Any  portion 
of  the  mordant  which  remains  soluble 
has  now  to  be  removed,  or  the  color 
when  applied  would  pass  beyond  the 
pattern.  It  is  removed  by  passing  the 
dry  calico  through  a  warm  mixture  of 
cowdung  and  water.  This  operation  is 
called  dunging.  It  is  then  washed  in 
water  in  a  urine  pit,  and  again  in  a  dash 
wheel.  By  this  process  the  thick  paste 
is  removed  which  accompanied  the  mor- 
dant. The  difficulty  of  procuring  cow- 
dunof  in  sufficient  quantity  has  led  to  the 
employment  of  other  substances,  which 
are  easily  procured,  and  which  are  found 
on  analysis  to  be  the  active  agents  in  the 
dung :    thus  solutions  of  phosphate  of 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


69 


soda  and  phosphate  of  lime,  thickened 
with  glue,  are  used  under  the  name  of 
substitute  for  this  purpose.  After  wash- 
ing in  cold  water,  the  cloth  mordanted^ 
is  rinsed  through  a  weak  solution  of 
substitute  and  size,  when  it  is  ready  for 
the  color :  this  is  laid  on  by  drawing  the 
cloth  for  two  or  three  hours  through  a 
colored  solution  {see  Dyeing)  ;  the  color 
attaches  itself  permanently  to  those  por- 
tions of  the  cloth  to  which  the  mordant 
has  been  applied,  and  form  a  chemical 
compound  with  it.  On  the  portions  not 
mordanted  the  color  is  so  fee ibly  attached 
as  to  be  removed  by  washing  in  soap 
and  water,  or  in  bran  and  water,  or  in  a 
dilute  solution  of  chloride  of  lime.  This 
is  called  clearing. 

The  processes  for  finishing  a  piece  of 
cloth,  even  with  one  color,  are  very  nu- 
merous :  thus  if  a  red  stripe  be  required 
on  a  white  ground,  no  less  than  nineteen 
processes  have  to  be  passed  through, 
viz.: 

1.  Printing  on  mordant  of  red  liquor 
(acetate  of  alumina)  thickened  with  flour, 
and  dyeing.  2.  Exposure  of  cloth  till 
mordant  is  altered.  3.  Dunging.  4. 
Wincing  in  cold  water.  5.  Washing  at 
the  dash-wheel.  6.  Wincing  in  dung  sub- 
stitute and  size.  7.  Wincing  in  cold  water. 
8.  Dyeing  in  madder.  9.  Wincing  in  cold 
water.  10.  Washing  with  dash  wheel. 
11.  Wincing  in  soap  water  with  a  salt  of 
tin.  12.  Dash-wheel  washing.  13.  Win- 
cing in  soap  water.  14.  Wincing  in  a  so- 
lution of  bleaching  powder.  15.  Washing 
at  the  dash- wheel.  16.  Drying  by  the 
water  extractor.  17.  Folding.  18.  Starch- 
ing. 19.  Drying  by  steam. 

From  this  it  "may  be  seen  how  impor- 
tant the  washing  and  rinsings  aret> 

In  steam  printing  the  mordant  is  first 
laid  on  and  the  cloth  then  dipped  in  the 
color  vat :  union  does  not  however  take 
place  between  the  mordant  and  the  color 
until  steam  is  brought  into  contact  with 
the  cloth,  when  immediately  the  two 
unite.  In  some  instances  the  cloth  is 
hung  in  a  room  into  which  steam  is  ad- 
mitted. In  other,  the  goods  are  put  in 
a  box  made  almost  steam  tight  and  the 
steam  admitted  through  a  pipe  perforated 
with  a  multitude  of  "small  holes;  most 
commonly  the  cloth  is  wrapped  round 
a  cylinder  perforated  with  holes  into 
which  the  steam  is  admitted  by  a  pipe. 
The  temperature  is  kept  at  212°  to  pre- 
vent condensation,  which  would  make 
the  colors  run ;  a  higher  temperature  is 
injurious.  The  steaming  is  carried  on 
for  half  an  hour  or  less  according  to  the 


nature  of  the  color.  This  gives  a  great 
brilliancy  and  delicacy  of  finish  to  the 
cloth.      A  variety  of  cheap  goods   are 

Srintedin  fugitive  colors  ;  these,  not  being 
xed  by  steaming  or  by  a  mordant,  are 
called  spirit  or  fancy  colors  :  they  wash 
off. 

The  padding  style  is  only  applied  to 
mineral  colors.  The  cloth  is  uniformly 
imbued  with  a  color  and  then  dried.  This 
color  is  sometimes  obtained  by  once  dip- 
ping in  the  trough ;  at  others  it  is  neces- 
sary to  dip  the  cloth  first  in  one  mineral 
solution  and  then  in  a  second,  when  an 
insoluble  color  becomes  fixed  in  the  tissue  ; 
after  each  dipping  the  cloth  is  dried,  or 
the  cloth  may  be  padded  in  one  solution 
and  afterwards  winced  in  the  other.  To 
produce  a  design  on  a  white  or  colored 
ground,  the  cloth  is  printed  with  one 
of  the  solutions  and  then  padded  or 
winced  in  the  other.  In  the  resist  style 
the  cloth  is  first  printed  with  a  resist 
paste  to  prevent  the  cloth  from  taking  up 
the  color  when  it  passes  through  the,  dye 
bath.  Some  resists  act  mechanically,  such 
as  fat  resists,  these  are  used  for  silk  ; 
others  act  chemically,  such  as  acetates  of 
copper  andlead,  chlorides  of  zinc,  and  mer- 
cury, and  arseniate  of  potash,  thickened 
with  gum,  pipe  clay,  and  til.  The  dis- 
charge style,  is  that  when  a  white  or  col- 
ored pattern  is  to  be  produced  upon  a 
colored  ground.  Here  the  mordanted 
cloth  is  printed  with  a  substance  called 
the  discharger,  which  acts  either  on  the 
coloring  matter,  or  on  the  mordant,  by 
converting  them  into  colorless  or  soluble 
matters,  which  may  be  removed  to  allow 
the  parts  thus  discharged  to  be  died  of 
another  color.  Vegetable  and  animal 
coloring  matters  are  discharged  by  chlo- 
rine and  chromic  acid,  and  a  mordant  is 
usually  discharged  by  an  acid  solution, 
such  as  lemon  or  lime  juice,  cream  tartar, 
oxalic,  citric,  and  weak  sulphuric  acids, 
thickened  with  gum  or  starch.  In  this 
way  are  produced  the  imitations  of  Ban- 
dana handkerchiefs,  in  which  white  fig- 
ures are  formed  on  a  ground  of  Turkey 
red  by  means  of  a  solution  of  chlorine, 
which  is  made  to  flow  through  the  red 
cloth  on  certain  points  defined  by  the 
pressure  of  hollow  lead  types,  inserted  in 
plates  of  lead  contained  in  a  hydraulic 
press.  This  is  furnished  with' pattern 
plates,  one  fixed  on  the  upper  block  and 
the  other  on  the  lower,  or  movable  plate. 
Fourteen  pieces,  previously  dyed  with 
Turkey  red,  are  laid  flat  and  smooth 
one  on  another,  the  whole  is  wound  on  a 
roller  at  the  back  of  the  press.   The  first 


70 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[CAL 


yard  is  then  unwound  and  laid  flat  on  the 
slab  of  the  machine.  Then  the  workman 
turning  a  handle  brings  the  pressure  to 
act  from  a  hydraulic  machine,  and  the 
bed  plate  rises  slowly  till  the  cloth  comes 
in  contact  with  the  upper  horizontal 
plate ;  such  is  the  power  of  the  machine 
that  the  cloth  is  pressed  between  the  two 
plates  with  a  force  of  300  tons.  The  chlo- 
rine liquor  is  then  poured  into  the  trough 
on  the  upper  plate,  and  after  remaining  a 
short  time  is  drawn  off  by  a  small  cock, 
the   pressure  is  removed  and  the  bed 

Slate  sinks  down ;  the  cloth  is  now  with- 
rawn  and  comes  out  diversified  with 
white  spots,  which  are  as  clearly  defined 
on  the  lowest  of  the  fourteen  as  on  the 
top  one.  The  red  dye  has  here  been  im- 
mediately removed  from  the  stuff  by  the 
chlorine ;  fifteen  minutes  is  found  to  be  a 
sufficiently  long  exposure.  These  white 
spaces  are  occasionally  dyed  of  another 
color  subsequently. 

The  China  Um  style  is  only  practised 
with  indigo.  The  bleached  cotton  is 
printed  of  the  desired  pattern  with  a  mix- 
ture of  indigo,  orpiment,  sulphate  of  iron, 
gum  and  water.  It  is  then  exposed  to 
the  air  for  two  days  and  then  stretched  on 
a  frame.  This  is  immersed  in  three  cis- 
terns containing  different  liquids  ;  1st,  in 
milk  of  lime ;  2d,  in  a  solution  of  sul- 
phate of  iron  ;  3d,  in  a  solution  of  caus- 
tic soda.  The  frames  are  dipped  several 
times  alternately  in  1  and  2.  The  dip- 
ping in  No.  3  is  less  often,  but  follows 
immediately  that  into  2.  The  insoluble 
indigo  which  had  been  applied  to  the 
surface  becomes  converted  into  solu- 
ble indigo  or  indigotin,  which  is  dissolved 
and  transferred  to  the  interior  of  the 
fibre  when  it  is  gradually  precipitated  in 
the  insoluble  form. 

CALIPER  COMPASSES,  or  simply 
Calipers,  are  compasses  with  curved 
legs,  for  measuring  the  caliber  or  di- 
ameter of  cylinders,  "balls,  or  other  round 
bodies.  Calipers  of  the  best  sort  are 
made  with  a  scale  having  different  sets  of 
numbers  engraved  on  it,  like  a  sliding 
rule,  for  the  purpose  of  exhibiting  at 
once  various  relations  depending  on  the 
magnitude  of  the  diameter  of  the  body 
measured.  Thus,  as  the  weights  of  balls 
of  the  same  metal  are  in  a  constant  ratio 
to  the  cubes  of  their  diameters,  the  scale 
may  be  so  graduated  and  numbered  that 
the  observer  may  read  oil'  either  the  di- 
ameter in  inches,*or  the  weight  in  pounds. 
Other  numbers  having  a  less  immediate 
application  arc  also  frequently  attached; 
for  example,  the  degrees  of  a  circle,  the 


proportions  of  troy  and  avoirdupois 
weight,  tables  of  the  specific  gravities 
and  weights  of  bodies,  &c.  It  is  obvious 
that  these  may  be  varied  infinitely,  ac- 
cording to  the  purposes  proposed  to  be 
accomplished. 

CALOMEL.  Protochloride  of  mercu- 
ry, composed  of  mercury  10,  chlorine  35. 
It  may  be  made  by  rubbing  mercury  with 
corrosive  sublimate,  and  applying  heat  to 
sublime  the  mixture;  the  white  powder 
which  rises  is  calomel :  this  is  called  sub- 
limed calomel.  Precipitated  calomel  is 
made  by  adding  proto-nitrate  of  mercury 
in  solution  to  a  solution  of  common  salt. 
Dr.  A.  T.  Thompson  has  patented  a  mode 
of  making  calomel,  by  combining  chlorine 
in  the  gaseous  state  with  the  vapor  of 
mercury.  Mr.  Jewel  prepares  a  finely 
divided  calomel  by  passing  its  vapor  into 
a  room  into  which  steam  was  admit- 
ted. It  is  one  of  the  most  useful  of 
medicines. 

CALOKIMETEE.  ^  An  instrument  for 
measuring  the  quantity  of  heat  given  out 
by  bodies  passing  from  one  temperature 
to  another. 

CALORIMOTOK.  This  terrn  has  oc- 
casionaly  been  appllied  to  a  peculiar  form 
of  the  voltaic  apparatus  composed  of  one 
pair  of  plates  or  great  extent  of  surface, 
the  electricity  of  which,  when  transmit- 
ted through  good  conductors,  produces 
intense  heat.  To  Dr.  Hare  of  Philadel- 
phia, the  philosophical  world  is  indebted 
tor  the  most  powerful  apparatus  of  this 
kind. 

CALOTYPE  is  the  name  given  by  Mr. 
II.  Pox  Talbot  to  his  improved  Photo- 
graphic method.  The  method  of  obtain- 
ing Caloty  pe  pictures  is  as  follows  : — Take 
a  sheet  of  the  best  writing  paper.  Dis- 
solve 100  grains  of  crystallized  nitrate  of 
silver  in  6  ounces  of  distilled  water. 
Wash  the  paper  with  this  solution,  with 
a  soft  brush,  on  one  side,  and  put  a  mark 
on  that  side,  whereby  to  know  it  again. 
Dry  the  paper  cautiously  by  a  distant 
fire,  or  else  let  it  dry  spontaneously  in  a 
dark  room.  When  dry,  or  nearly  so,  dip 
it  into  a  solution  of  iodine  of  potassium, 
of  500  grains  to  a  pint  of  distilled  water, 
and  let  it  stay  two  or  three  minutes  in 
this  solution."  Then  dip  it  into  a  vessel 
of  water,  dry  it  lightly  with  blotting  pa- 
per, and  finish  drying  it  at  a  fire,  or  spon- 
taneously. All  this  is  best  done  by 
candlelight.  The  paper  so  prepared  the 
author  calls  iodized  paper.  It  is  scarcely 
sensitive  to  light;  nevertheless  it  ought 
to  be  kept  protected  from  the  'light. 
Shortly  before  this  paper  is  wanted  for 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


71 


use,  wash  a  sheet  of  it  with  this  liquid: 
Dissolve  100  grs.  of  crystallized  nitrate  of 
silver  in  2  oz.  of  distilled  water ;  add  one 
sixth  of  its  volume  of  strong  acetic  acid  : 
let  this  mixture  be  called  A.  Make  a 
saturated  solution  of  crystallized  gallic 
acid  in  cold  distilled  water  ;  the  quanti- 
ty dissolved  is  very  small ;  call  this  so- 
lution B.  When  a  sheet  of  paper  is 
wanted  for  use,  mix  together  the  liquids 
A  and  B  in  equal  volumes,  hut  only  mix 
a  small  quantity  of  them  at  a  time,  he- 
cause  the  mixture  will  not  keep  long 
without  spoiling ;  call  this  mixture  the 
gallo-nitrate  of  silver.  With  it  wash  the 
iodized  paper  on  the  marked  side,  by 
candlelight.  Let  the  paper  rest  half  a 
minute,  and  then  dip  it  into  water,  Then 
dry  it  lightly  with  blotting  paper,  and  at 
a  distance  from  the  fire.  The  author  has 
named  the  paper  thus  prepared  Calotype 
paper,  on  account  of  its  great  utility  in 
obtaining  the  pictures  of  objects  with  the 
camera  obscura.  If  this  paper  be  kept 
in  a  press,  it  will  often  retain  its  quali- 
ties in  perfection  for  three  months  or 
more,  being  ready  for  use  at  any  mo- 
ment ;  but  this  is  not  uniformly  the  case. 
It  is  best  used  a  few  hours  after  it  has 
been  prepared.  The  Calotype  paper  is 
sensitive  to  light  in  an  extraordinary 
degree,  which  transcends  a  hundred 
times  or  more  that  of  any  kind  of  photo- 
genic paper ;  it  will  take  an  impression 
From  simple  moonlight  not  concentrated 
by  a  lens. 

Use  of  the  Paper. — Take  a  piece  of 
this  paper,  and  having  covered  half  of  it, 
expose  the  other  half  to  daylight  for  the 
space  of  one  second  in  dark  cloudy 
weather  in  winter,  when  there  will  be  a 
strong  impression  upon  the  paper,  but 
latent  and  invisible,  and  its  existence  not 
to  be  suspected  by  any  one.  To  make  it 
visible  wash  the  paper  once  more  with 
the  gallo-nitrate  of  silver,  and  then  warm 
it  gently  before 'the  fire.  In  a  few  se- 
conds, the  part  of  the  paper  upon  which 
the  light  has  acted  begins  to  darken,  and 
finally  grows  entirely  black,  while  the 
other  part  of  the  paper  retains  its  whiter 
nass.  This  paper  is  well  suited  to  re- 
ceive images  in  the  camera  obscura. 
When  the  aperture  of  the  lens  amounts 
to  one  third  of  the  focal  length,  and  the 
object  is  very  white,  as  a  plaster  bust, 
&c.,  one  second  is  sufficient  to  obtain  a 
pretty  good  image  of  it,  made  visible  bv 
washing  and  warming. 

<  T7ie  Fixing  Process.— First  wash  the 
picture  with  water,  then  lightly  dry  it 
with  blotting-paper,   and  next  wash  it 


with  a  solution  of  hromide  of  potassium, 
containing  100  grains  of  that  salt  dis- 
solved in  eight  or  ten  ounces  of  distilled 
water.  After  a  minute  or  two  it  should 
be  again  dipped  in  water,  and  then  finally 
dried.  The  picture  is  in  this  manner 
very  strongly  fixed ;  and  with  this  great 
advantage,  that  it  remains  transparent, 
and  that,  therefore,  there  is  no  difficulty 
in  obtaining  a  copy  of  it.  The  Calotype 
picture  is  a  negative  one,  in  which  the 
lights  of  nature  are  represented  by 
shades  ;  but  the  copies  are  positive,  hav- 
ing the  lights  conformable  to  nature.  A 
negative  calotype  may  serve  to  furnish 
several  positive  ones,  but  after  a  while  it 
grows  faint ;  but  it  may  be  restored  by 
washing  by  candlelight  with  gallo-nitrate 
of  silver,  and  warming.  A  second  series 
may  now  be  taken. 

CALP.  Argillaceous  limestone,  con- 
taining sulphuret  of  iron  and  vegetable 
matter. 

CAMBRIC.  Very  fine  white  linen, 
first  made  at  Cambray,  in  Flanders, 
whence  its  name. 

CAMEL.  A  machine  invented  by  the 
Dutch  for  carrying  vessels  into  harbors, 
where  there  is  not  a  sufficient  depth  of 
water.  It  consists  of  two  large  boxes, 
or  half  ships,  built  in  such  a  manner  that 
they  could  be  applied  on  each  side  of  the 
hull  of  a  large  vessel.  On  the  deck  of 
each  part  of  the  camel  a  number  of  hori- 
zontal windlasses  were  placed,  from  which 
ropes  proceeded  on  one  side,  and  being 
carried  under  the  keel  of  the  vessel, 
were  attached  to  the  windlasses  on  the 
deck  of  the  other  part.  When  about  to 
be  used,  as  much  water  as  necessary  was 
suffered  to  run  into  them ;  all  the  ropes 
were  then  cast  loose,  and  large  beams 
were  then  placed  horizontally"  through 
the  port-holes  of  the  vessel,  the  ends 
resting  on  the  camels  alongside.  When 
the  ropes  were  made  fast,  and  the  vessel 
properly  secured,  the  water  was  pumped 
out,  on  which  the  camels  rose  and  bore 
up  the  vessel. 

A  ship  drawing  15  feet  can  be  made 
by  one  of  these  "to  draw  only  11  feet. 
The  length  of  one  of  these  camels  was 
127  feet,  and  the  greatest  breadth  22 
feet. 

CAMLET,  or  CAMBLET.  A  light 
stuff,  of  several  varieties.  Some  are  made 
of  goat's  hair  ;  in  some  the  warp  is  hair, 
and  the  woof  hair  or  silk:  others  en- 
tirely of  wool,  or  a  warp  of  wool  and  a 
woof  of  thread.  Camlets  may  be  striped, 
watered,  and  figured. 
CAMPIIENE.    One  of  the  hydrocar- 


72 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CAN 


bons,  composed  of  10  atom3  of  carbon 
and  8  atoms  of  hydrogen.  It  is  identi- 
cal with  oil  of  turpentine.  Camphor 
may  be  looked  on  as  its  protoxide — a 
term  applied  to  one  of  the  numerous 
fluids  used  for  illumination :  it  is  made 
of  one  part  of  oil  of  turpentine,  mixed 
with  about  twelve  parts  of  alcohol,  and 
then  distilled. 

CAMPHOR..  The  produce  of  the  cam- 
phor laurel  of  Japan  and  China.  The 
roots  and  wood  chopped  small  are  boiled 
with  water  in  an  iron  vessel,  to  which  an 
earthen  cap,  filled  with  straw,  is  fitted.  The 
camphor  sublimes,  and  is  condensed  up- 
on the  straw.  There  are  two  kinds  of 
camphor;  1,  the  Dutch  or  Japan  cam- 
phor; and  2,  the  crude  or  China  cain- 
Shor.  The  first  is  the  finest  quality, 
rude  camphor  resembles  moist  sugar 
before  it  is  refined.  This  process  is  car- 
ried on  in  thin  glass  globes,  which  are 
filled  with  crude  camphor,  with  a  little 
bone-black  and  quick-lime.  The  globe  is 
then  placed  on  a  water  bath,  and  boiled. 
The  camphor  rises  and  sublimes  upon 
the  upper  part  of  the  vessel.  When  the 
sublimation  is  completed,  the  vessel  is 
cracked  by  pouring  cold  water  on  it  while 
hot,  and  the  cake  of  camphor  is  removed. 
Camphor  (C10  H8  O)  is  a  white  and  semi- 
transparent  solid  of  a  crystalline  fracture, 
and  warm  pungent  taste.  It  is  soft  and 
tough,  and  not  easily  powdered,  until 
mixed  with  spirit  of  wine.  It  evaporates 
in  the  air,  and  in  phials  at  ordinary  tem- 

Eeratures,  and  attaches  itself  to  the  sur- 
ice  most  exposed  to  the  light. 

Camphor  floats  on  water,  and  ro- 
tates rapidly  if  the  water  be  clean  ;  if  the 
surface  be  greasv,  the  phenomenon  will 
cease.  It  fuses  at  347°,  and  boils  at  400°, 
is  sparingly  soluble  in  water  (about  5 
grains  in  a  pint)  but  readily  in  alcohol, 
ether,  sulphuret  of  carbon,  a  few  volatile 
oils,  and  other  substances.  It  is  used  as  a 
stimulant,  both  externally  and  internally, 
but  it  is  a  powerful  poison.  It  is  also 
used  in  some  varnishes. 

CAMPHORIC  ACID.  Obtained  by 
boiling  camphor  in  nitric  acid  ;  its  com- 
position is  C'»  H?  03XH  0. 

CAMWOOD.  A  red  dye-wood,  ob- 
tained from  Sierra  Leone.  Its  coloring 
matter  differs  but  little  from  Nicaragua 
wood. 

CANAL.  An  artificial  channel  filled 
with  water,  formed  for  the  purpose  of 
draining,  irrigation,  supplying  towns  with 
water,  or  of  inland  navigation.  The  Cay- 
uga Canal,  which  drains  the  marshes  at 
the  head  of  the  lake,  and  empties  into 


the  Ontario  Lake,  is  an  illustration  of  the 
first.  Those  of  Ancient  Egypt  are  the  best 
instances  of  the  second.  The  supplying 
stream  from  the  Croton  river  to  the  re- 
ceiving basins  in  New  York,  illustrates 
the  third.  It  is  to  the  fourth  kind,  that 
for  inland  navigation,  that  the  term  is 
now  almost  wholly  restricted. 

There  is  no  country  in  the  world  where 
the  advantages  of  canals  are  more  appre- 
ciated than  in  China.  From  time  imme- 
morial the  rivers  that  intersect  that  vast 
empire  have  been  united  by  innumerable 
canals ;  and  the  Grand  Canal  is  said  to 
be  the  most  stupendous  work  of  the  kind 
that  has  ever  been  executed.  Russia, 
too,  exhibits  a  remarkable  degree  of  en- 
terprise in  the  construction  of  canals  for 
the  purpose  of  inland  navigation ;  and 
though  innumerable  difficulties  peculiar 
to  that  country  for  a  long  period  impeded 
the  progress  of  works  of  this  description, 
that  empire  is  now  traversed  by  an  un- 
broken line  of  water  communication  from 
St.  Petersburg  to  the  Caspian  Sea. 

The  section  of  a  canal  is  usually  a  tra- 
pezium, of  which  two  sides  are  parallel 
and  horizontal,  and  the  other  two  equally 
inclined  to  the  horizon.  The  inclination 
depends  on  the  nature  of  the  soil.  It  is 
least  in  tenacious  earth,  and  greatest  in 
loose  soil ;  but  no  soil  will  maintain  itself 
unless  the  base  of  the  slope  exceeds  its 
height  at  least  in  the  ratio  of  four  to 
three.  In  loose  soils  the  base  requires 
to  be  twice  as  great  as  the  height. 

A  canal  is  usually  confined  between  a 
bank  on  one  side,  and  a  towing  path  on 
the  other,  the  breadth  of  whose  upper 
surface  must  be  sufficient  for  a  road  on 
which  the  animals  employed  in  draught 
may  easily  pass.  This  requires  the 
breadth  of  the  upper  surface  to  be  at 
least  9  feet.  The  usual  mode  for  the 
other  bank  is  to  make  the  breadth  at  top 
equal  to  the  height,  measured  from  the 
bottom  of  the  canal:  but  in  this  case 
there  should  be  a  berm  of  a  foot,  or  a  foot 
and  a  half,  at  the  level  of  the  water,  which 
increases  the  thickness  of  the  bank  at 
bottom,  and  prevents  the  wash  of  the 
banks  from  tailing  into  the  canal.  To 
prevent  the  entrance  of  rain-water,  a 
counter-ditcTi  is  formed  on  the  outside  of 
each  of  the  banks.  The  form  of  a  wcll- 
constructed  canal  will  therefore  present 
the  following  figure  :— 


The  dimensions  of  navigable  canals 
must  depend  on  the  size  of  the  vessels  in- 
tended to  navigate  them.    In  order  that 


can] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


■78 


they  may  enable  two  vessels  to  pass  each 
other  with  freedom,  the  breadth  at  bot- 
tom is  usually  made  twice  as  great  as  the 
breadth  of  the  beam  of  the  vessels ;  the 
depth  requires  to  be   at  least  one  foot 
more  than  the  vessel's  draught  of  water. 
The  bed  of  a  canal  must  be  absolutely 
level,  or  have  no  more  slope  than  is  ne- 
cessary to  convey  water  to  replace  that 
which  has  been  wasted.    Hence,  when  a 
canal  intersects  a  sloping  country  in  a  se- 
ries   of    channels    at    different    levels, 
means  must  be  provided  to  enable  vessels 
to  pass  from  one  level  to  another.    This 
is  commonly  effected  by  means  of  a  lock. 
The  invention  of  locks  as  a  means  of 
carrying  a  canal  through  an  undulating 
country  has  given  an  entirely  new  fea- 
ture to  the  inland  navigation  of  Europe. 
Various  nations  have  claimed  the  honor 
of  this  invention ;  but  it  would  appear 
that  the  controversy  which  has  arisen  on 
the  subject  is  not  yet  settled.      A  lock 
is  a  chamber,  formed  of  masonry,  occu- 
pying the  whole  bed  of  the  canal  where 
the  difference  of  level  is  to  be  overcome. 
This  chamber  is  so  contrived  that  the 
level  of  the    water    which    it   contains 
may  be  made  to  coincide  with   either 
the  upper  or  lower  level  of  the   canal. 
This  is  effected  by  two  pairs  of  gates, 
one  of  which  pairs  is  placed   at  each 
end  of  the  chamber  of  the  lock.    By 
this  means,  while  the  gates  at  the  lower 
end  of  the   chamber  are    opened,   and 
those  at  the  upper  end  are  closed,  the  wa- 
ter in   the   chamber  will   stand   at  the 
lower  level  of  the  canal;  and  on  the  con- 
trary, when  the  lower  gates  are  closed, 
and  the  upper  ones  are  opened,  the  level 
of  the  water  in  the  lock  will  coincide  with 
the  level  of  the  water  in  the  upper  part 
of  the  canal.    In  the  first  case,  a  boat 
may  be  floated  into  the  lock  from  the 
lower  part  of  the  canal;  and  if  then  the 
gates  be  closed,  and  water  is  admitted 
into  the  lock  from  the  upper  level  unite 
the  surface  of  the  lock  is  in  a  line  with 
the  water  above,  the  boat  will  be  floated 
up,  and  on  the  opening  of  the  upper 
gates  may  be  passed  onward.   By  revers- 
ing the  course  of  procedure,  boats  may 
be  as  readily  conveyed  from  the  upper  to 
the  lower  level.     (See  Lock.) 

The  supply  of  water  required  for  main- 
taining a  canal  depends  on  the  lockage 
or  quantity  wasted  in  passing  a  vessel 
through  the  locks,  on  the  evaporation 
from  the  surface,  and  on  the  leakage.  It 
has  been  found  by  experiment  that  the 
annual  quantity  of  evaporation  from  the 
canal  of  Languedoc  is  32  inches ;  that  is 


to  say,  the  body  of  water  required  to 
supply  this  waste  is  equal  to  a  parallelo- 
piped  whose  base  is  the  whole  surface  of 
water  in  the  canal,  and  whose  altitude  is 
32   inches :    in  most  calculations  it  has 
been  customary  to  take  this  altitude  at  36 
inches.     With  respect  to  the    leakage, 
when  the  soil  is  porous  the  inner  surface 
of  the  banks  may  be  lined  with  an  earth 
retentive  of  water,  or  a  portion  of  the 
middle  of  each  bank  may  be   built  up 
with  earth  of  this  character.    The  opera- 
tion of  lining  a  bank  with  clay,  or  earth 
retentive  of  moisture,  is  called  puddling. 
The  advantages   derived  from   canals 
are  now  so  generally  known  and  acknow- 
ledged, as  to  render  it  almost  superfluous 
to  allude  to  the  question.     The  beneficial 
effects  of  canals  are  felt  in  a  greater  or 
less  degree  by  all  classes  of  society:  by 
their  means  the  manufacturer  is  enabled 
to  collect  his  materials  and  his  fuel  with 
less  labor  and  expense  ;  the  farmer  ob- 
tains a  supply  of  manure  at  a  cheap  rate, 
and  a  ready  conveyance  of  his  produce  to 
the    most  profitable  market;    and    the 
merchant  is  enabled  to  extend  his  com- 
merce  by  exporting  greater  quantities 
and  varieties  of  goods  from  places  remote 
from  the  sea,  and  by  more  easily  supply- 
ing a  wider    extent  of  inland  country 
-with  articles    of   foreign  produce.      In 
short,  general  arguments  in  favor  of  ca- 
nals are  superseded  by  the  rapidly  im- 
proving and  thriving  state  of  all  the  ci- 
ties, towns,  and  villages  in  their  neigh- 
borhood ;  while  the  great  works  of  every 
kind  to  which  they  have  been  conducted, 
and  to  which  a  large  portion  of  them  owe 
their  rise,  are  their  best  recommenda- 
tion.   Experience   has   shown  that    the 
formation  of  railroads  does  not  yet  su- 
persede the  necessity  for  canals,  as  where 
cheapness,   and   not    expedition,   is  re- 
quired, the  canal  will  be  preferred.    The 
general  introduction  of  steam  propulsion 
on  our  canals  would  be  of  great  service. 
It  has  been  tried  on  the  Erie,  and  Chesa/- 
peake,  and  Ohio  Canals. 

CANDLE.  Candles  can  be  made  from 
any  fatty  substance  which,  at  ordinary 
temperatures,  is  in  a  solid  state ;  wax, 
spermaceti,  and  tallow  being  the  usual 
substances  employed.  That  very  essen- 
tial part  of  a  candle,  the  wick,  performs 
an  office  which  involves  a  scrap  of  philo- 
sophy not  always  well  understood.  The 
wick  is  composed  of  a  dozen  or  more 
fibres  of  soft  cotton,  ranged  side  by  side, 
and  having  just  sufficient  twist  given 
them  to  make  them  cling  together.  The 
threads  are  not  so  close  together  but  that 


14: 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[can 


oil,  or  tallow  in  a  melted  state,  will  as- 
cend between  them,  by  virtue  of  that  ca- 
pillary attraction  which  will  cause  a  piece 
of  loaf-sugar  to  become  wet  throughout, 
if  placed  on  a  wet  spot.  When  a  candle 
is  lighted,  the  heat  melts  the  upper  part 
of  the  tallow,  which  then  ascends  between 
the  fibres  of  the  wick,  and  furnishes 
minute  streams  of  combustible  matter  as 
fast  as  the  oxygen  of  the  air  will  consume 
it  in  the  form  of  flame.  The  current  of 
air  constantly  supplying  oxygen,  keeps 
the  outer  surface  ot  the  tallow  cool,  and 
causes  the  formation  of  the  cup  which 
contains  the  melted  tallow  that  other- 
wise would  run  down  and  disfigure  the 
candle  :  the  tallow  is  the  combustible 
matter,  and  the  wick  is  the  series  of 
tubes  through  which  it  ascends  to  the 
flame.  Wax  candles  are  made  by  pouring 
melted  wax  over  the  wicks,  which  for 
the  convenience  of  turning  and  placing 
them  successively  over  the  caldron,  are 
usually  attached  to  the  circumference  of 
a  hoop  ;  when  of  a  proper  thickness,  they 
are  rolled  smooth  upon  a  table,  and  the 
ends  are  cut  and  trimmed.  It  is  in  con- 
w.quence  of  this  method  of  manufacture, 
that  when  we  cut  a  wax  candle  we  ob- 
serve it  composed  of  successive  layers  or 
coats.  Attempts  have  been  made  to  cast 
wax  candles  in  moulds,  but  those  which 
are  thus  made  never  burn  so  well  as 
those  which  are  poured.  Spermaceti  can- 
dles, are  mixtures  of  wax  and  spermaceti. 
This  material  forms  a  very  good  and 
cleanly  candle ;  but  in  consequence  of  its 
ready  fusibility  and  hardness  when  con- 
crete, it  does  not  admit  of  being  carried 
about  without  spilling  the  melted  mate- 
rial. The  fused  portions  also,  which  run 
down  the  candle^  are  apt  to  curl  and  fall 
upon  the  table.  Composition  candles. 
This  term  was  originally  conferred  by  a 
manufacturer  who  had  a  large  stock  of 
spermaceti  candles  on  hand  which  were 
of  a  dirty  hue,  and  which  therefore  were 
ansalable  ;  he  advertised  them  under 
the  above  name,  and  they  were  soon  dis- 
posed of,  under  the  notion  of  their  being 
composed  of  some  new  combination  of 
materials.  The  term  has  since  been  ap- 
plied to  various  mixtures ;  but  what  are 
now  sold  under  the  name  of  composition 
candles  are  chiefly  mixtures  of  sperma- 
ceti, tallow,  and  a  little  resin,  and  occa- 
sionally wax.  Tallow  candles,  which  are 
either  cast  upon  the  wick  in  pewter 
moulds,  or  made  by  dipping  the  wicks, 
attached  in  rows  to  proper  frames,  into 
melted  tallow.  Stearine  candles.  Under 
this  term  we  may  include  cocoa-nut  oil 


candles,  and  a  few  others  made  of  the 
stearine,  or  what  may  be  compared  to 
the  spermaceti  of  the  vegetable  oils.  The 
stearine,  or  rather  the  stearic  acid  of  tal- 
low, is  also  now  extensively  employed 
for  making  candles.  Mould  candles  are 
made  in  two  ways.  1.  From  ten  to  six- 
teen cylindrical  pewter  moulds  are  placed 
together  in  a  wooden  frame,  so  that  their 
upper  ends  terminate  in  a  kind  of  trough 
common  to  the  whole.  The  wicks  are 
inserted  and  kept  firmly  in  their  proper 
places  in  the  centre  of  each  cylinder  by 
strong  wires.  The  frame  being  then 
placed  with  the  trough  uppermost,  the 
moulds  are  filled  with  melted  tallow,  and 
are  placed  in  the  air  to  cool,  after  which 
the  wires  by  which  the  wicks  have  been 
fixed  are  withdrawn,  the  superfluous  tal- 
low is  removed  from  the  trough,  and  the 
candles  are  pulled  out  of  the  moulds. 

In  the  following  illustration  of  a  mould 
candle  machine,  a  represents  the  candle, 
b  the  mould  through  which  the  candles 
are  pushed  by  the  rod  c. 

Messrs.  Mattewson,  candle  manufac- 
turers of  Baltimore,  have  introduced  a 
new  English  patent  machine  for  making 
candles,  which  is  both  ingenious  and 
possesses  uncommon  merit  in  an  econo- 
mical point  of  view. 

It  consists  of  a  number  of  moulds, 
holding  18  each,  which  are  furnished 
with  a  bobbin  to  each  mould,  holding 
wick  for  over  100  candles  on  each  bobbin. 

At  the  commencement,  the  first  mould 
is  threaded  by  hand.  It  is  then  placed 
on  a  railroad  and  brought  under  a  cistern 
from  which  it  is  filled  with  tallow ;  it  is 
then  shoved  along  to  a  carriage,  which, 
when  it  has  received  its  load,  is  convey- 
ed by  rail  outside  to  an  open  shed  in  the 
yard,  where  it  is  allowed  to  cool.  "When 
that  operation  is  completed  it  still  con- 
tinues its  circuit  on  the  railroad,  until  it 
arrives  at  the  machine,  upon  which  it  is 
placed,  and  a  stroke  of  a  lever  ejects  the 
whole  18  candles,  at  the  same  time 
threading  the  moulds  for  a  fresh  charge ; 
a  revolving  saw-knife  cuts  oft7  the  wicks 
as  quick  as  the  hand  can  move  it  across 
the  machine ;  the  ends  of  the  wicks  are 
seized  by  pincers,  which  grip  each  of 
them  as  a  person  would  with  the  finger 
and  thumb;  it  is  again  placed  on  the 
rail  and  continues  its  course  to  undergo 
the  same  operation.  On  their  way  over 
the  rail  they  are  interrupted  by  a  person 
who  removes  the  pincers  and  trims  the 
butt-ends  of  the  candles. 

Mr.  A.  L.  Brown  of  New  Haven,  Conn., 
took  out  a  patent  in  October,  1849,  for  an 


can] 


CYCLOPEDIA    OP   THE    USEFUL    ARTS. 


76 


improved  moulding 
apparatus.  The  im- 
provement in  this 
apparatus  consists 
in  constructing  the 
mould  with  a  screw- 
on  the  upper  part, 
about  two  inches 
from  the  end,  for  ad- 
justing and  secur- 
ing it  in  the  frame, 
and  a  shoulder  near 
the  upper  end,  to 
support  the  tallow 
table,  and  a  hole  to 
admit  the  wire  which 
supports  the  wick  : 
also  in  attaching  all 
the  wires  which  sup- 
port the  wicks  to  a 
slide  worked  by  a 
jointed  wire  han- 
dle, and  governed 
by  a  guard,  so  that  _ 
be  evened  by  one  motion  of  the  hand, 
and  then  be  all  centred  by  another 
motion ;  also  in  using  a  smooth  tallow 
table,  level  with  the  tops  of  the  moulds, 
to  allow  the  tallow  to  be  easily  scraped 
off  and  the  whole  kept  clean. 

Fig.  1,   is  a  side-view  of  one  of  the 
moulds,   showing   the   screw  by  which 
FIG.l.  fig.  2. 


the  wicks  may 


it  is  to  be  adjusted  and  secured  in  the 
frame;  the  shoulder  on  which  the  tal- 
low table  rests,  and  the  hole  through 
which  the  wire  passes.  Fig.  2,  is  a  sec- 
tional view  of  one  of  the  moulds,  show- 
ing the  wick  when  in  the  mould,  as 
supported  by  the  wire. 

Great  care  is  requisite  in  selecting  the 
cotton  for  the  wicks  of  candles,  which 
should  be  of  such  a  nature  as  to  leave  no 
ash,  or  scarcely  any,  when  burned.  The 
wick  is  occasionally  impregnated  with 
different  substances,  and  sometimes  so 
platted  as  to  curl  out  of  the  flame.  The 
following  table  contains  the  results  of 
some  experiments  made  by  Dr.  Ure,  with 
a  view  of  ascertaining  the  relative  inten- 


sities of  light  and  the  duration  of  dif- 
ferent candles : 


a   . 
fl 

il 

il 
P 

il 

P 

0 

|| 

S 

s  . 

U 

3  § 

o 

oM 

£ 

w 

2  ° 

10  Mould 

5  h.  9  m. 

682 

132 

12.25 

68-0 

5-70 

10  dipped 

4    36 

672 

150 

13.00 

65-5 

5  25 

8  Mould 

6    31 

856 

132 

10.50 

59  5 

6  60 

6  Ditto 

7    2* 
9    36 

1160 

163 

14.66 

660 

5-00 

4  Ditto 

1787 

186 

20.25 

80-9 

3  50 

Argand  oil  flame 

512 

69.40 

100*0 

In  reference  to  the  above  table,  it  ap- 
pearsfrom  Dr.  Ure's  experiments  that 
one-eighth  of  a  gallon  of  good  oil,  weigh- 
idg  6,010  grains,  or  13  and  l-10th  ounces 
avoirdupois,  lasts  in  a  bright  argand  lamp 
11  hours  44  minutes.  The  weight  of  oil 
it  consumes  per  hour  is  equal  to  four 
times  the  weight  of  tallow  in  candles 
eight  to  the  pound,  and  3  and  l-7th  times 
the  weight  of  tallow  in  candles  six  to  the 
pound ;  but,  its  light  being  equal  to  that 
of  five  of  the  latter  candles,  it  appears 
from  the  above  table,  that  two  lbs.  weight 
of  oil,  value  one  shilling  (sterling),  in  an 
argand  lamp,  are  equivalent  in  illuminat- 
ing power  to  3  lbs.  of  tallow  candles, 
which  cost  about  three  shillings,  sterling. 
The  larger  the  flame  in  the  above  candles, 
the  greater  the  economy  of  light.  In  re- 
ference to  the  comparative  cost  of  coal 
gas,  oil,  tallow,  and  wax,  it  appears  that 
the  cost  of  a  lamp  fed  by  gas,  and  giving 
the  light  of  about  seven  candles,  will  be 


76 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CAO 


cannon  are 


about  one  penny  sterling  per  hour  ;  of  an 
argand  lamp,  "fed  with  spermaceti  oil 
about  threepence,  of  mould  candles  about 
threepence-halfpenny,  and  of  wax  candles 
about  one  shilling.  Ninety  cubic  feet  of 
good  coal  gas,  value  about  one  shilling 
sterling,  will  produce  the  light  of  about 
ten  wax  candles  for  one  hour. 

CANE  MILL.  {See  Sugar,  Manufac- 
ture of.) 

CANNELL  COAL.  (Perhaps  candle 
coal,  from  the  flame  with  which  it  burns.'* 
A  species  of  coal  found  in  most  of  the 
English  collieries;  especially  at  Wigan  in 
Lancashire.  It  is  difficultly  frangible, 
does  not  soil  the  Angers ;  when  burn- 
ing it  splits  and  crackles,  but  does  not 
cake,  and  leaves  3  or  4  per  cent,  of  ash.  It 
is  sometimes  worked  into  ornamental 
utensils,  like  jet. 

CANNON.  A  military  engine  for  pro- 
jecting balls,  shells,  &c,  by  the  force  of 
gunpowder.  The  principal  parts  of  a 
1.  The  breech,  which  is  the 
solid  metal  from  the  bottom 
of  the  bore,  or  concave  cy- 
linder, to  the  extremity  of 
the  cascabel,  a.  2.  The  trun- 
nions, b  b,  which  project  on 
each  side,  and  serve  to  sup- 
port the  cannon  in  equili- 
brio,  their  axis  being  in 
the  vertical  plane  passing 
through  the  centre  of  gra- 
vity, but  intersecting  it  be- 
low that  point.  3.  The  bore 
or  cylindrical  cavity.  This 
in  several  sorts  of  cannon  is  made  of 
smaller  diameter  towards  the  breech,  thus 
assuming  the  shape  of  two  cylinders, 
united  by  a  portion' of  a  spherical  surface. 
The  smaller  part  of  the  bore  is  of  such  a 
length  as  to  receive  the  maximum  service 
charge  of  gunpowder,  and  is  called  the 
chamber.  The  entrance  of  the  bore,  c,  is 
called  the  mouth  or  muzzle. 

Cannon  are  made  either  of  cast  iron  or 
brass,  the  latter  being  an  alloy  of  copper 
and  tin,  in  the  proportion  of  about  10 
parts  of  copper  to  1  of  tin,  and  called 
gun-metal.  This  has  a  greater  tenacity 
than  iron,  but  is  objectionable  on  account 
of  its  greater  density  and  higher  price, 
besides  being  liable  "in  rapid  service  to 
soften  and  droop  at  the  muzzle,  whereby 
it  is  rendered  unserviceable.  Since  the 
advantage  of  using  smaller  charges  of 
gunpowder  was  discovered,  cast  iron, 
though  possessing  less  tenacity  than  gun- 
metal,  has  been  substituted  for  ship,  gar- 
rison, and  battering  guns.  But  the  small- 


er species  of  cannon  (field-pieces)  con- 
tinue to  be  made  generally  of  brass  :  for 
by  reason  of  the  rapid  cooling  of  the  iron 
in  small  masses  its  strength  is  considera- 
bly impaired,  so  that  it  is  difficult  to  be 
procured  of  the  requisite  quality. 

Cannon  were  formerly  cast  with  a  cave 
or  hollow,  but  they  are  now  always  cast 
solid;  experience  having  shown  that 
when  cast  solid  they  are  stronger,  and 
less  liable  to  burst,  that  the  metal  is  freer 
from  honeycombs,  and  that  the  bore,  can 
be  rendered  more  perfect,  and  its  axis 
made  to  coincide  more  accurately  with 
that  of  the  piece.  In  boring  cannon,  the 
gun  itself  is  made  to  revolve  about  the 
bit  or  borer,  the  size  of  which  is  succes- 
sively increased. 

CANNON-METAL.  Bronze;  a  cop- 
per alloy. 

CANVAS.  A  very  clear  unbleached 
cloth  of  hemp  or  flax,  woven  regularly  in 
little  squares,  chiefly  used  to  make  sails 
for  shipping.  Besides  serving  for  various 
domestic  purposes,  such  as  for  the  ground 
of  tapestry  work,  canvas  forms  the  cloth 
on  which  painters  usually  draw  their  pic- 
tures. 

A  kind  of  canvas  made  solely  from 
hemp,  and  called  huckaback,  is  used  for 
coarse  towels  and  table-cloths. 

CAOUTCHOUC.  This  curious  sub- 
stance is  the  inspissated  juice  or  sap  of 
several  plants ;  the  principal  supplies  are 
from  South  America  and  Java,  and  are 
derived  from  the  Shphonia  elastica  (Hevea 
caoutchouc),  and  probably  from  other  Eu- 
phorbiaceous  plants.  It  is  often  termed 
gum  elastic  and  India-rubber.  Its  gen- 
eral properties  and  uses  arc  well  known. 
Among  its  more  recent  applications  are 
those  of  elastic  wove  fabrics,  formed  of 
caoutchouc  stretched  into  threads  and 
covered  with  cotton  ;  and  various  water- 
proof clothing,  which  is  made  by  inter- 
posing a  layer  of  caoutchouc  between  two 
folds  of  the  cloth,  and  then  forcibly  unit- 
ing them  by  pressure.  For  this  purpose 
the  caoutchouc  is  dissolved  by  coal  naph- 
tha, and  in  that  state  brushed  over  the 
surfaces  which  are  to  be  united. 

Caoutchouc  is  a  compound  of  carbon 
and  hydrogen ;  when  heated  it  fuses,  and 
afterwards  remains  viscid.  When  sub- 
jected to  destructive  distillation  at  a  high 
temperature,  it  yields  4-5ths  of  its  weight 
of  a  highly  inflammable  and  very  light 
volatile  oily  liquid  (hydrocarbon),  which 
has  been  called  caouUhovcine,  and  which 
is  a  good  solvent  of  the  unaltered  caout- 
chouc. Washed  sulphuric  ether  dissolves 


CAPJ 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


11 


caoutchouc,  and  it  is  also  soluble  in  sev- 
eral essential  oils  ;  but  of  these  latter  so- 
lutions the  greater  number  leave  it  in  a 
sticky  state  on  evaporation. 

The  trees  have  incisions  made  into 
them  through  the  bark ;  the  milky  juice 
exudes,  is  collected  on  clay  moulds,  dried 
in  the  sun,  or  with  the  smoke  of  a  lire, 
which  blackens  it.  The  juice  itself  is  a 
pale  yellow,  creamy  liquid,  which  is  mis- 
cible  in  water ;  it  dries  off  into  caoutchouc, 
and  loses  55  per  cent.  Caoutchouc  is  in- 
soluble in  alcohol,  but  is  soluble  (besides 
ether),  in  naphtha  from  coal,  oils  of  sassa- 
fras and  lavender,  and  linseed  oil.  It 
melts  at  248°,  and  burns  with  a  bright 
flame  and  much  smoke.  It  is  not  acted 
on  by  caustic  potass,  cold  sulphuric  acid, 
nor  nitric  acid,  unless  very  concentrated. 
From  its  great  elasticity  it  has  been  used 
in  articles  of  dress  and  machinery.  (See 
Elastic  Bands.) 

The  India-rubber  manufacture  is  one 
of  the  most  important  branches  of  art, 
rivalling  that  of  some  of  the  older  textile 
fabrics.  In  this  country  it  has  made  pro- 
digious strides  within  a  few  years.  The 
India-rubber  shoes  are  made  by  women 
on  the  Amazon,  by  dipping  the  lasts,  sent 
there  from  this  country,  into  the  juice  of 
the  tree,  and  then  holding  the  last  over 
a  palm  Are  to  dry  it  off  quickly  ;  the  last 
is  then  dipped  again  in  the  milk,  and 
again  dried,  and  "so  repeated  till  it  ac- 
quires the  due  thickness ;  this  is  com- 
pleted in  five  minutes.  Two  gallons  of 
milk  suffice  for  ten  pair  of  shoes.  The 
shoes  are  then  sun-dried,  and  next  day 
stamped  with  pointed  sticks,  or  the  spines 
of  the  palm.  The  shoe  is  then  cut  from 
the  last,  and  is  ready  for  packing. 

From  its  softness  and  impermeability 
it  is  made  into  bougies,  catheters,  gas- 
tubes,  and  bottles.  Its  use  as  a  varnish  is 
almost  endless,  dissolved  in  any  of  the 
solvents  previously  mentioned,  or  in  bi- 
sulphuret  of  carbon,  without  the  use  of 
heat.  This  constitutes  Parker's  patent 
solvent.  Chloroform  is  an  excellent  sol- 
vent, but  it  is  too  costly.  By  digesting 
the  rubber  in  solution  of  carbonate  of 
soda,  or  water  of  ammonia,  previously,  it 
dissolves  more  readily. 

India-rubber  is  now  rarely  used  alone 
in  manufacture,  but  is  previously  mixed 
with  other  matters,  which  do  not  to  any 
great  extent  affect  its  elasticity,  or  its 
waterproof  properties.  By  mixing  in 
sulphur  when  the  rubber  is  in  a  semi- 
fluid condition  it  is  said  to  be  vulcanized, 
but  as  this  gives  an  unpleasant  odor  to 
Uie  fabric,  various  improvements  have 


been  made  to  obviate  it.  Patents  have 
been  taken  out  to  use  the  hyposulphites, 
either  alone  or  combined  with  sulphites 
and  sulphurets.  The  sulphuret  ot  anti- 
mony has  been  used  with  advantage. 
In  another  patent  the  rubber  after  being 
steamed  and  dried  is  thionized,  which 
consists  in  submitting  the  mass  to  the 
action  of  the  fumes  of  sulphur  or  sul- 
phurous acid,  by  which  the  sulphur  be- 
comes incorporated.  For  manufactur* 
the  rubber  is  now  never  prepared  by  so 
lution  in  turpentine  or  other  menstruum 
but  it  is  reduced  into  a  pasty  mass  bj 
heavy  grinding,  and  then  passed  througl 
a  succession  of  rollers  until  it  is  brought 
into  sheets  of  uniform  texture. 

CAOUTCHOUCINE.  A  volatile  hy 
drocarbon  obtained  by  distilling  India 
rubber  in  an  iron  vessel  at  600°  Fahr. 
it  is  purified  by  rectification,  when  it  ia 
colorless,  and  has  a  sp.  gr.  of  680.  Thi"' 
liquid  is  a  solvent  for  caoutchouc,  copal 
and  very  many  resinous  and  oleaginous 
bodies  when  combined  with  alcohol.  Ir 
the  liquid  state  it  is  the  lightest  liquid 
known,  but  its  vapor  is  so  heavy  that  it 
may  be  transferred  from  one  vessel  to 
another  by  simple  pouring.  The  liquid 
is  very  volatile,  mixes  readily  with  oils, 
and  renders  viscid  oil  paint  liquid.  Its 
constitution  is  C8  II7. 

CAPERS.  The  buds  or  unexpanded 
flowers  of  the  Capparis  spinosa,  in  com- 
mon use  as  a  pickle. 

•  CAPSICUM.  The  berry  or  seed-ves- 
sel of  different  species  of  capsicum.  The 
larger  pods  of  the  Capsicum  annunm) 
and  the  smaller  ones  of  the  C.  baccatum 
or  bird  pepper,  when  powdered,  form  the 
Kyan  pepper  of  commerce,  so  well  known 
as  a  powerful  condiment,  and  often  use- 
ful as  a  stimulating  medicine.  Kyan 
pepper  is  often  grossly  adulterated  with 
common  salt,  and  occasionally  red  lead 
and  earthy  powders  are  said  to  be  added 
to  it :  it  often  has  a  disagreeable  rancid 
odor,  owing  to  its  being  sprinkled  with 
oil  to  prevent  its  dust  affecting  those 
who  powder  and  sift  it. 

CAPSTAN,  sometimes  called  CAP- 
STERN.  A  strong  massive  piece  of 
timber,  in  the  form  of  a  cylinder  or  trun- 
cated cone,  round  which  a  rope  is  coiled  ; 
and  being  turned  by  means  of  bars  or 
levers,  it  affords  an  advantageous  mode 
of  applying  power  to  overcome  an  ob- 
stacle. The  capstan  is  chiefly  employed 
in  ships,  where  it  is  used  for  weighing 
anchors,  hoisting  sails,  &c.  It  is  gene- 
rally placed  vertically,  the  lower  end  be- 
ing' let  down  through  the  deck  of  the 


18 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[car 


ship,  and  the  levers 
inserted  in  holes  in  the 
head  or  top;  so  that 
the  force  of  the  men 
can  be  exerted  con- 
tinuously, and  that 
there  may  be  no  ne- 
cessity for  removing 
the  levers  from  one  hole  to  another,  as 
is  the  case  when  it  is  placed  horizontally. 
The  power  of  the  capstan  may  be  greatly 
increased  by  adapting  an  arrangement 
of  wheel  work  to  it — an  improvement 
which  has  been  adopted  for  several  years 
past  in  the  navy. 

Improved  forms  of  capstan  have  been 
patented  in  this  country  within  the  last 
few  years. 

CARAT.  A  weight  used  by  gold- 
smiths and  jewellers.  Originally  the 
Kuara  bean  was  used  for  this  purpose — 
hence  the  name.  A  carat  is  a  weight  of 
4  grains,  used  in  weighing  diamonds. 
The  term  carat  is  also  used  in  reference 
to  the  fineness  of  gold,  in  expressing 
which  the  mass  spoken  of  is  supposed 
to  weigh  24  carats,  of  12  grains  each  ; 
and  the  pure  gold  is  called  fine.  Thus, 
if  gold  be  said  to  be  22  carats  fine  (or 
standard),  it  is  implied  that  22-24ths  are 
pure  gold,  and  2-24ths  alloy.  In  the 
process  of  assaying  gold,  the  real  quan- 
tity taken  is  very  small,  generally  from 
6  to  12  grains ;  and  this  is  termed  the 
assay  pound.  It  is  subdivided  into  24 
carats,  and  each  carat  into  4  assay  grains, 
and  each  grain  into  quarters;  so  that 
there  are  384  separate  reports  for  gold. 
"When  the  gold  assay  pound  is  only  6 
grains,  the  quarter  assay  grain  only 
weighs  l-64th  of  a  grain.  'This  will  give 
an  idea  of  the  accuracy  required  in  the 
weights  and  scales  used  for  such  delicate 
operations. 

CAEBON  in  a  perfectly  pure  state 
is  the  diamond :  less  pure  forms  are 
plumbago,  graphite,  coke,  anthracite, 
and  charcoal.  For  its  various  proper- 
ties, see  these  different  heads.  The 
soot  and  smoke  of  lamps,  gas,  and  other 
substances  of  vegetable  origin,  is  carbon 
almost  pure.  Carbon  has  many  uses  :  it 
forms  the  base  of  a  durable  ink ;  of 
crayons ;  of  the  filtering  substance,  such 
as  common  charcoal,  bone,  and  ivory 
black.  It  is  an  admirable  manure  for 
the  soil :  it  is  one  of  the  best  substances 
for  reducing  metals.  When  a  piece  of 
charcoal,  which  is  very  clean,  and  free 
from  ash,  is  immersed  in  a  solution  of 
metallic  salt,  the  metal  itself  is  deposited 
on  the  charcoal  with  all  its  natural  bril- 


i  liancy.    Salts  of  tin,  copper,  platina,  sil- 
ver,  and  gold,    furnish   very  beautiful 
i  deposits.      When  the  salts  are  too  acid 
j  these  effects  are    not  produced.      The 
i  weak  salts  of  copper  often  yield  upon 
|  charcoal  the  most  varied  shades  of  color, 
j  from  the  rich  azure  blue  to  the  deep  cop- 
per   color.      There    are    some  parts   of 
charcoal  for  which  some  metals  exhibit  a 
preference  to  that  of  others. 

In  the  three  first  forms  it  has  a  crys- 
talline arrangement.  In  the  others  it  is 
amorphous,  and  generally  presents  itself 
as  a  black,  brittle,  hard  substance,  easily 
powdered,  and  quite  unalterable  at  com- 
mon temperatures. 

CAEBON ATES.  Salts  containing  car- 
bonic acid.  They  are  recognized  by  the 
effervescence  which  is  excited  when  they 
are  put  into  dilute  muriatic  acid.  Carbo- 
nate of  lime  is  one  of  the  most  important 
of  these  compounds,  forming  the  vari- 
eties of  marble,  limestone,  calcareous 
spar,  chalk,  &c.  Carbonate  of  lime  con- 
sists of 

Lime 1  atom=  ..28.. 56 

Carbonic  acid  1     "     =  . .  22 . .  44 

1  50  100 

Carbonate  of  potash  and  carbonate  of 
soda  are  also  important  salts.  (See  Pot- 
ash, Soda.)  Carbonate  of  ammonia  is 
used  in  medicine  ;  it  is  a  white  pungent 
salt,  commonly  known  under  the  name 
of  smelling  salt.  Spirits  of  hartshorn  is  a 
solution  of  impure  carbonate  of  am- 
monia, obtained  by  distilling  bone  or 
horn. 

CAEBONIC  ACID.  This  important 
compound  is  obtained  when  any  form  of 
carbon,  such  as  the  diamond  or  pure 
charcoal,  is  burned  in  oxygen  gas.  It 
consists  of  6  carbon -{-16  oxygen  =22 
carbonic  acid ;  or  of 

Carbon  .  .1  atom 6 27-27 

Oxygen.. 2    "     ...  .16.. .  .72-73 

1  22       100-00 

100  cubical  inches  of  carbonic  acid  gas 
Aveigh  47-3  grains.  Under  a  pressure  of 
36  atmospheres,  at  the  temperature  of 
32°,  it  becomes  liquid;  and  when  the 
pressure  which  retains  it  in  the  liquid 
state  is  removed,  the  rapidity  of  the 
evaporation,  and  the  sudden  and  enor- 
mous expansion  of  the  vapor,  are  such 
as  to  produce  a  degree  of  cold  under 
which  the  acid  solidifies,  forming  a  white 
concrete  substance  possessed  of  very  ex- 
traordinary properties.  Mr.  Faradav  was 
the  first  who  liquefied  carbonic  acid,  but 


car] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


79 


it  was  first  described  as  a  solid  by  M. 
Thilourier. 

At  common  temperatures  and  pres- 
sures water  absorbs  its  own  volume  of 
carbonic  acid;  under  a  pressure  of  two 
atmospheres  it  dissolves  twice  its  vol- 
ume, and  so  on.  Carbonic  acid  imparts 
briskness  and  a  slightly  pungent  and 
sour  taste  to  water  thus  impregnated 
with  it :  it  also  confers  the  effervescent 
quality  upon  many  mineral  springs.  Car- 
bonic acid  is  recognised  by  its  rendering 
lime-water  turbid.  It  extinquishes  flame 
and  suffocates  animals  ;  hence  the  miners 
call  it  choke  damp.  Carbonic  acid  is  con- 
tained in  marble,  chalk,  and  all  the  va- 
rieties of  lime-stone;  from  which  it  is 
extracted  by  strong  heat,  as  in  the  pro- 
cess of  burning  lime  ;  or  by  the  action 
of  stronger  acids,  in  which  case  the  car- 
bonic acid  escapes  with  effervescence. 
Mountains  of  lime-stone,  therefore,  are 
great  natural  repositories  of  carbonic 
acid.  This  gas  is  also  produced  during 
the  respiration  of  animals,  and  is  evolved 
in  the  process  ot  fermentation. 

CARBONIC  OXIDE.  A  gas  com- 
posed of 

Carbon  .  .1  atom 6 42-8 

Oxygen.. 1     "     ....  8 57-2 

4  14        100-0 

100  cubical  inches  weigh  30*2  grains.  It 
is  fatal  to  animals,  and  extinguishes 
flame  ;  but  it  burns  in  contact  with  air, 
and  forms  carbonic  acid.  It  is  obtained 
by  passing  carbonic  acid  over  red-hot 
charcoal,  or  by  heating  a  mixture  of  chalk 
or  pounded  marble  and  iron  or  zinc  fil- 
ings to  redness.  It  is  not  absorbed  by 
water. 

CARBONIFEROUS.  A  geological 
term,  generally  applied  to  beds  or  strata 
containing  coal. 

CARBOY.    A  large  globular  bottle  of 

green  glass  protected  "by  basket-work, 
arboys  are  seldom  used,  except  for  con- 
taining certain  acids  and  other  highly 
corrosive  liquids  likelv  to  act  upon  stone- 
ware. A  carboy  of  oil  of  vitriol  usually 
contains  about  160  lbs.  of  that  acid,  or  12 
gallons  of  water. 

CARBUNCLE.  The  ancient  name  of 
a  gem,  probably  corresponding  with  our 
precious  aarnet. 

CARBURET  OF  SULPHUR.  A  lim- 
pid volatile  liquid  of  fetid  smell  and  acrid 
taste.  It  boils  at  112°  F.,  and  eva- 
porates so  rapidly  as  to  congeal  mercury 
in  a  vacuum.    It  is  composed  of  two 


atoms  of  sulphur  and  one  of  carbon.  It 
is  used  as  a  solvent  for  caoutchouc. 

CARBURETTED  HYDROGEN.  A 
generic  name  for  the  compounds  of  car- 
bon and  hydrogen,  of  which  there  are 
several,  viz. :  oil  and  coal  gas,  oil  of  lem- 
ons, turpentine,  naphtha,  otto  of  rcses,  &c. 

CARDS — Carding  Machines.  Instru- 
ments for  arranging  cotton  and  other 
fibres.  After  picking  and  disentangling, 
the  cotton  is  in  the  form  of  a  very  clean, 
light,  downy  substance,  consisting  of 
short  fibres  thoroughly  disentangled.  But 
these  fibres  are  not  parallel:  they  lie 
across  each  other  at  every  imaginable  an- 
gle, and  any  attempt  to  combine  them  to- 
gether in  this  state  would  be  fruitless ; 
they  must  be  rendered  parallel,  and  to 
effect  this  is  the  object  of  the  beautiful 
operation  of  carding,  one  of  those  which 
have  exercised  such  a  large  amount  of  in- 
ventive ingenuity.  If  we  were  to  take 
two  combs,  and  pass  the  teeth  of  one  be- 
tween those  of  the  other,  we  should  have 
a  rude  idea  of  the  process  of  carding,  es- 
pecially if  we  had  a  few  fibres  of  cotton 
entangled  among  the  teeth  :  for  the  move- 
ment of  the  two  combs  would  tend  to  ar- 
range the  fibres  in  some  degree  parallel. 
A  number  of  pieces  of  wire  are  inserted 
in  a  piece  of  wood  or  leather,  so  that  all 
shall  project  to  an  equal  distance  and  at 
an  equal  angle  ;  and  if  two  such  pieces 
of  apparatuswere  placed  with  their  wires 
in  contact,  and  moved  in  contrary  direc- 
tions, a  few  fibres  of  cotton  placed  on  the 
lower  one  would  be  combed  out  by  the  up- 
per one,  and  arranged  parallel.  In  vari- 
ous stages  of  the  history  of  the  manufac- 
ture, the  two  cards  have  been  arranged  in 
different  ways.  Sometimes  one  was  on  a 
convex  surface,  and  the  other  on  a  con- 
cave surface  fitted  to  it ;  sometimes  one 
was  on  a  cylinder,  and  the  other  on  a  flat 
surface ;  sometimes  both  were  on  the 
surfaces  of  cylinders.  But  the  principle 
of  action  is  the  same  in  all,  and  is  nothing 
more  or  less  than  a  process  of  combing. 
In  some  arrangements  the  cotton  is 
brought  into  the" form  of  a  "  lap,"  or  flat 
layer,'  by  the  scutching-machine,  and  in 
that  state  transferred  "to  the  carding-en- 
gine ;  while  in  other  cases  the  latter  is 
fed  by  hand  with  cotton. 

These  card-combs  arc  sometimes  set  on 
cylinders,  and  applied  to  the  burring  and 
carding  of  cotton  and  avooI. 

In  1848,  letters  patent  were  granted  for 
the  mode  of  constructing  the  hollow  cy- 
linder, to  which  the  teeth  of  burring  or 
carding  cylinders  are  to  be  attached.  A 
light  cylinder  of  tinned  sheet  metal  is  first 


80 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[car 


made, — wire,  covered  with  tin,  is  then 
wound  tight  and  spirally  all  over  the  con- 
vex surface  of  the  cylinder.  Metal  pro- 
per for  soldering  is  then  poured  over  the 
surface  thus  formed,  which  renders  the 
whole  firm  and  compact,  the  surface  is 
then  turned  true,  and  the  cylinder  is 
ready  to  receive  the  teeth  of  such  charac- 
ter as  may  be  desired. 

In  the  same  year  patents  were  granted 
for  a  new  method  of  constructing  burring 
cylinders.  A  proper  cylinder  is  first  con- 
structed for  the  reception  of  the  teeth, 
wire  of  proper  size  is  then  rolled  flat,  and 
afterwards  planed  in  such  a  manner  as  to 
leave  a  rib  or  shoulder  its  whole  length 
on  the  one  side,  and  a  thin  edge  on  the 
other.  Notches  are  then  filed  into  the 
thin  edge  at  intervals,  thus  forming  teeth. 
The  convex  surface  of  the  cylinder  is  then 
grooved  at  proper  intervals  around  its 
surface,  and  the  toothed  strips  on  the 
edge  having  the  shoulder,  are  laid  into  I 
the  groove,  and  the  ridges  of  metal  be- 
tween the  grooves  are  forced  down  upon 
the  shoulders  to  hold  them  in  place ;  or 
the  toothed  strips  are  wound  upon  the 
cylinder  and  soldered,  and  the  cylinder  is 
finished,  the  shoulders,  &c,  giving  pro- 
per distance  between  the  rows  of  teeth. 

A  patent  was  also  granted  for  a  carding 
machine,  in  which  a  cylinder,  like  Park- 
hurst's  burring  cylinder,  is  made  to  work 
against  the  main  cylinder.  When  cards 
are  used  the  teeth  will  yield,  and  a  knot, 
closely  matted  together,  might  be  carried 
through  the  machine  without  being  pro- 
perly opened ;  but  the  cylinder  above- 
mentioned  would  hold  such  a  knot,  and 
bring  it  successively  in  contact  with  the 
teeth  of  the  main  cylinder,  until  by  de- 
priza  it  would  be  opened  and  carried  for- 
ward. 

Another  patent  has  been  granted  for 
improvements  in  this  variety  of  machines, 
which  consists  principally  in  banding 
i*om  the  main  cylinder,  and  thus  giving 
a  high  speed  to'  the  workers  with  little 
increase  of  power. 

Messrs.  J.  Lambert  and  J.  Zimmerman, 
of  Waterloo,  New  York,  have  made  an 
improvement  in  the  working  of  carding 
machines,  for  which  they  have  taken  mea- 
sures for  a  patent,  and  which  is  said  to 
card  double  the  quantity  at  least,  in  the 
same  time,  that  has  usually  been  done 
by  the  old  mode  of  operation.  The 
"  workers,"  instead  of  carrying  round 
the  wool  from  the  main  cylinder,  at  once, 
by  revolving  in  a  contrary  direction,  re- 
volve with  it,  and  carry  the  wool  but  a 
short  distance  to  the  strippers,  and  thus, 


by  the  way,  they  are  geared ;  the  "work- 
ers" are  rendered  workers  indeed,  and 
not  merelv  in  name. 

CAEM1NE.  A  brilliant  lake,  made  of 
the  coloring  matter  of  the  cochineal  in- 
sect, combined  with  alumina  and  oxide  of 
tin.  It  is  of  different  shades, — either  de- 
pendent on  the  amount  of  alumina  pre- 
sent, or  of  the  adulterations  to  which  it 
is  liable.  Vermillion  is  a  common  one  of 
these.  It  is  always  easy  to  discover  the 
amount  of  impurity,  as  true  carmine  dis- 
solves in  water  of  ammonia,  and  leaves 
the  adulteration  behind.  Starch  is  a  com- 
mon impurity.  To  make  ordinary  car- 
mine, take  1  lb.  powdered  cochineal,  Si 
drachms  of  carbonate  of  potash,  1  oz.  of 
alum,  and  3£  drachms  of  fish  glue ;  boil 
the  cochineal  and  potash  together  in 
thirty  quarts  of  water  in  a  copper,  take  it 
off  the  fire,  and  let  it  settle,  then  add  the 
alum  in  powder :  after  fifteen  minutes  the 
liquor  clears,  and  may  be  decanted  from 
the  sediment, — the  bright  clear  fluid  con- 
taining the  carmine.  This  is  next  de- 
canted into  another  copper,  the  glue  dis- 
solved in  a  large  quantity  of  water  added, 
and  the  whole  boiled ;  th*e  carmine  separ- 
ates from  the  liquid,  and  rises  like  a  scum 
to  the  top ;  this  must  be  collected,  and 
drained  on  a  filter  of  canvas  or  linen. 

The  China  carmine  is  made  by  adding 
to  the  solution  of  cochineal  and  alum, 
when  freed  from  sediment,  a  solution  of 
tin  (chloride),  until  the  carmine  ceases  to 
be  thrown  down.  Ordinary  carmine  may 
be  brightened  by  dissolving  in  water  of 
ammonia,  and  precipitating  by  acetic 
acid,  washing  in  alcohol,  and  drying. 
Carmine,  dissolved  in  ammonia,  is  used 
by  painters,  and  called  liquid  carmine. 
Carmine  is  used  in  miniature  painting, 
fine  inks,  water  colors,  and  artificial  flower 
tinting,  because  it  is  more  transparent 
than  the  other  colors. 

CAEPET.  An  ornamental  covering  for 
the  floor.  The  manufacture  of  carpets  is 
carried  on  to  great  perfection  in  this 
country.  The  principal  varieties  are  the 
Brussels,  Axminster,  Wilton,  Kidder- 
minster, and  Venetian.  They  are  gener- 
ally composed  of  linen  and  Avorsted.  In 
some  the  pile  is  cut  so  as  to  give  the  car- 
pet the  character  of  velvet,  as  in  the  Wil- 
ton carpets.  Kidderminster  or  Scotch 
carpets  are  entirely  fabricated  of  wool. 

The  manufacture  may  be  classed  under 
two  heads:  that  of  double  fabrics,  and 
that  cut  to  imitate  velvets.  The-  Jacquard 
■loom  has  lately  been  used  in  carpet  manu- 
tacture. 

Plain  Venetian  carpets  for  stairs  and 


car] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


81 


passages,  are  woven  in  simple  looms,  pro- 
vided with  common  heddles  and  reed. 
The  warp  should  be  a  substance  of  wor- 
sted yarn  so  as  to  cover  in  the  weft.  Kid- 
derminsters are  composed  of  two  woollen 
webs  which  intersect  each  other,  so  as  to 
produce  definite  figures.  Brussels  carpet- 
ing has  a  basis  composed  of  a  warp  and 
woof  of  strong  linen  thread.  In  the  warp 
there  is  added  to  every  two  threads  of 
linen  ten  threads  of  woollen,  of  different 
colors.  The  use  of  the  linen  thread  is  to 
bind  the  worsted  together,  and  is  not  visi- 
ble on  the  upper  surface.  The  worsted 
yarn,  which  is  raised  to  form  the  pile,  is 
not  cut ;  in  the  Wilton  it  is  cut.  The 
following  figure  and  description  will  ex- 
plain the  construction  of  the  three-ply 
imperial  Scotch  and  two-ply  Kiddermin- 
ster carpet-loom,  which  is  merelv  a  modi- 
fication of  the  J  acquard  metier.  The  Brus- 
sels carpet-loom,  on  the  contrary,  is  a 
draw-boy  loom  on  the  damask  plan,  and 
requires  the  weaver  to  have  an  assistant. 


Fig.  a  a  a,  is  the  frame  of  the  loom,  con- 
sisting of  four  upright  posts,  with  caps 
and  cross-rails  to  bind  them  together. 
The  posts  are  about  six  feet  high,  c  c, 
the  cloth-beam,  is  a  wooden  cylinder,  six- 
inches  or  thereby  in  diameter,  of  suffi- 
cient length  to  traverse  the  loom,  with 
iron  gudgeons  in  the  two  ends,  which 
work  in  bushes  in  the  side  frame.  On 
one  end  of  this  beam  is  a  ratchet-wheel, 
with  a  tooth  to  keep  it  from  turning  round 
backwards  by  the  tension  of  the  web.    r>, 


the  lay,  with  its  reed,  its  under  and  up- 
per shell,  its  two  lateral  rulers  or  swords, 
and  rocking-tree  above.  There  are 
grooves  in  the  upper  and  under  shell,  in 
to  which  the  reed  is  fitted,  e,  the  hed- 
dles, or  harness,  with  a  double  neck  at- 
tached to  each  of  the  tower  or  card  me  • 
onanisms  ff,  of  the  Jacquard  loom.  The 
heddles  are  connected  and  work  with  the 
treddles  u  b,  by  means  of  cords,  as  shown 
in  the  figure,  o  g  are  wooden  boxes  for 
the  cards.    11,  the  yarn  or  warp-beam. 

Mr.  James  Templeton,  of  Glasgow, 
Scotland,  has  taken  out  a  patent  in  Eng- 
land for  an  improved  method  of  manu- 
facturing carpets,  the  designs  of  which 
are  produced  from  the  weft  threads, 
which  are  previously  printed*  to  produce 
the  design  or  pattern.  He  makes  velvet- 
carpets  by  employing  chenile  weft,  previ- 
ously printed,  which  weaves  up  into  the 
Eatterns  designed ;  he  also  makes  carpets 
y  the  printed  weft,  which  work  up  into 
patterns  on  both  sides  of  the  carpet,  like 
those  of  the  ingrain  carpet.  The  princi- 
ple of  this  important  improvement  in 
carpet-weaving  to  do  away  with  the  Jac- 
quard, lies  in  the  mode  of  printing  and 
preparing  the  weft  previous  to  weaving. 

The  most  extensive  manufacturers  in 
the  United  States  are  at  Thompsonville. 
They  use  10,000,000  lbs.  of  wool,  and 
10,000  lbs.  of  flax-yarn  per  annum.  They 
manufacture  three-ply  Brussels  and  Ax- 
minster  carpeting  ot  the  richest  patterns, 
the  weaving  being  mostly  done  at  pre- 
sent on  hand-looms.  They  have,  how- 
ever, introduced  power-looms  into  this 
factory,  for  weaving  rugs  and  Axminster 
carpets.  The  wool  for  Axminster  carpet- 
ing is  first  woven  in  a  web,  and  afterwards 
cut  in  strips,  forming  what  is  called  che- 
nile card ;  this  is  done  on  a  machine,  in- 
vented by  Messrs.  Davidson  and  Parks, 
of  Springfield,  Vt.,  which  is  the  first  and 
only  one  of  the  kind,  and  has  more  than 
paid  for  itself  in  six  months.  This  ma- 
chine has  over  200  hundred  cutters,  or 
knives,  which  are  attached  to  a  cylinder, 
making  some  300  revolutions,  and  cutting 
full  two  yards  of  the  web  per  minute  into 
strips,  which  being  passed  over  a  grooved 
cylinder,  heated  by  having  hot  irons  in- 
serted within  it,  it*  is  prepared  for  weav- 
ing. Besides  the  large  carpet  establish- 
ment, there  is  in  the  same  village  a  fac- 
tory, 150  feet  by  143  on  the  group,  and 
five  stories  high,  for  the  manufacture  of 
knit  shirts,  drawers,  and  fancy  ginghams. 
This  establishment  has  30  sets  of  wool 
cards,  and  25  or  30  gingham  rooms. 

CAKTHAMUS.    {See  Safflowek.)  : 


82 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[< 


CASE.  Is  the  receptacle  for  the  types, 
from  which  the  compositor  gathers  them 
separately,  and  arranges  them  in  lines 
and  pages  to  print  from.  They  are  al- 
ways in  pairs ;  one  of  which  is  styled  the 
upper  case,  and  is  divided  into  ninety- 
eight  boxes  or  recesses  of  equal  size,  in 
which  are  deposited  the  capitals,  small 
capitals,  accented  letters,  figures,  &c. ; 
the  other  is  styled  the  lower  case,  and  is 
divided  into  fifty-four  boxes  or  recesses, 
of  unequal  size,  containing  the  small  let- 
ters, spaces,  &c,  the  letters  most  in  use 
having  the  largest  boxes  assigned  to 
them.  The  cases  are  two  feet  nine  inches 
long,  one  foot  four  inches  and  a  half 
broad,  and  a  full  inch  deep. 

CASE  HAKDENING.  A  process  by 
which  tools *and  other  iron  articles  have 
their  surfaces  converted  into  steel.  This 
is  sometimes  effected  by  putting  the  arti- 
cles into  an  iron  box  filled  with  charcoal, 
and  cemented  together  for  some  time ;  by 
this  means,  a  thin  coating  of  steel  is 
formed  on  the  outside.  Immersion  of 
the  articles  in  boiling  water  or  boiling 
oil  partially  steels  the"  surface.  Ferrocy- 
anide  of  potassium  is  used  in  powder  for 
this  purpose,  thus  : — the  article  when 
polished  is  made  red  hot,  then  rubbed 
with  the  powdered  salt.  It  is  decom- 
posed by  the  heat,  and  the  iron  is  then 
quenched  in  cold  water.  Gas  flame  hard- 
ens iron  verv  well. 

CASHMERE  SHAWLS.  First  im- 
ported from  that  province,  now  imitated 
in  France  to  great  perfection.  They  are 
made  from  the  downy  wool  found  about 
the  roots  of  the  hair  of  the  Thibet  goat. 
The  oriental  cashmeres  are  woven  by 
slow  processes,  and  bring  from  500  tb 
2000  dollars  each,  on  sale,  but  with  the 
draw  loom  and  the  jacquard  loom  the 
French  shawls  rival  the  oriental,  and 
some  of  them  have  the  advantage  of  be- 
ing woven  without  seam  in  a  single 
piece. 

CASSAVA,   or    Tapioca,  is    obtained 

frincipaily  from  the  Jatroplia  Manioc. 
ts  extraction  is  remarkable  for  the  large 
quantity  of  hydrocyanic  acid  which  the 
juice  of  that  plant  contains.  When  dis- 
tilled, it  affords,  as  a  first  product,  a  li- 
quor which,  in  the  dose  of  30  drops, 
will  cause  the  death  of  a  man  in  the 
course  of  six  minutes ;  and  it  is  well 
known  that  this  acid  does  not  pre-exist 
in  the  plant,  but  that  it  is  generated  in 
it,  after  it  is  grated  down  into  a  pulp.  It 
would  be  interesting  to  discover  in  what 
state  the  substance  exists,  from  which  it 


proceeds.  After  the  grating  of  the  root, 
and  washing  of  the  pulp,  this  is  dried 
upon  hot  plates,  to  agglutinate  it  into 
the  form  of  concretions,  constituting  the 
tapioca  of  commerce.  But  the  starch  of 
the  washed  root  floated  in  water,  is  spon- 
taneously deposited,  and,  when  dried  in 
the  sun,  forms  Cassava  flour,  called  mous- 
tache by  the  French. 

CASSIUS,  PUEPLE  OF.  So  called 
from  its  inventor.  A  beautiful  purple 
used  in  porcelain  painting,  and  for  stain- 
ing glass.  It  is  formed  by  immersing 
tin  in  a  solution  of  gold.  It  is  probably 
a  mixture  of  oxide  of  tin  and  finely  di- 
vided gold. 

CASTING— of  Guns.  A  new  method 
has  been  resorted  to  at  the  Cannon  Foun- 
dry, near  Pittsburgh,  for  the  production 
of  guns.  Instead  of  bringing  them  from 
the  mould  solid,  and  afterwards  boring 
them,  they  are  cast  with  the  proper  bore, 
the  core  being  carefully  prepared  so  as  to 
enclose  a  circle  of  cold  water,  which  it 
receives  and  discharges  in  a  continuous 
current,  during  the  process  of  cooling, 
the  object,  probably,  being  to  chill  the 
inner  surface  more  rapidly  than  the  outer, 
and  thereby  give  it  a  greater  density  and 
strength.  The  plan  is  the  suggestion  of 
Lieut.  Rodman  :  and  two  guns — one  cast 
on  the  old  and  the  other  on  the  new  plan 
— having  been  subjected  to  the  usual 
tests,  the  first  exploded  on  the  84th,  and 
the  latter  on  the  255th  round.  This 
shows  a  great  superiority  over  the  com- 
mon mode  of  making  cannon,  and  if  fu- 
ture experiments  substantiate  this  suc- 
cessful one,  Lieut.  Rodman's  invention 
will  come  into  general  use. 

CASTING— in  Metal.    (See  Foundry.) 

CATECHU.  The  extract  of  the  Aca- 
cia Catechu,  an  astringent  substance, 
consisting  of  tannin  and  extractive  mat- 
ter imported  from  Bengal  and  Bombay. 
The  tannin  constitutes  one-half  of  the 
extract,  and  unlike  that  from  galls,  is  sol- 
uble in  alcohol,  and  more  soluble  in  water. 
It  is  much  used  for  brown  color  in  dye- 
ing and  calico-printing. 

CATGUT.  The  strings  of  musical  in- 
struments, clock  cords,  and  a  few  other 
materials  of  support,  are  made  of  an  ani- 
mal substance  called  catgut,  which  is  the 
twisted  muscular  coat  of  the  intestines 
of  cattle  and  sheep.  To  separate  the 
muscular  from  the  peritoneal  and  mu- 
cous coats,  the  intestine  is  steeped,  scour- 
ed, fermented,  and  inflated.  It  is  then 
twisted,  rubbed  smooth  with  horsehair, 
bleached  with  sulphur,  and  dried.    Tho 


bal] 


CYCLOPEDIA    OF   THE    USEFUL    MtTS. 


Italian  catgut  for  violin  and  harp-strings 
is  the  finest.  Lean  animals  furnish  the 
best  catgut ;  hence  this  manufacture 
might  in  our  Western  States  be  made 
not  only  profitable,  but  of  superior  qual- 
ity. 

CAUSTIC,  Lunar,  is  the  salt  obtained 
by  evaporating  gently  the  nitric  acid  so- 
lution of  silver  to  dryness,  in  a  silver 
vessel,  continuing  the  neat  until  it  melts ; 
and  when  in  fusion,  pouring  it  into 
moulds,  or  cast  it  into  sticks,  the  size  of 
the  barrel  of  a  common  quill. 

CAVIAR.  The  salted  row  of  the  stur- 
geon :  a  manufacture  confined  to  the 
Russians. 

CAULKING-  SHIP  consists  in  driving 
a  quantity  of  oakum  or  old  ropes  un- 
twisted, and  drawn  asunder  into  the 
seams  of  the  planks,  or  in  the  intervals, 
where  the  planks  are  joined  together  in 
the  ships,  deck,  or  sides,  in  order  to 
prevent  the  entrance  of  water.  After 
the  oakum  is  driven  into  these  seams,  it 
is  covered  with  hot  melted  pitch  or  resin 
to  keep  the  water  from  rotting  it. 
Among  the  Poles  in  Europe  a  sort  of 
unctuous  clay  is  used  for  the  same  pur- 
pose on  their  navigable  rivers. 

CEDE  A.  The  "fruit  of  a  species  of 
citron,  having  a  thick  peel,  and  an  epi- 
dermis having  a  fragrant  and  essential 
oil.    The  peelis  used  in  making  liqueur. 

CELESTINE.  Native  sulphate  of 
strontia;  decomposed  by  ignition  with 
charcoal  into  sulphuret  of  strontia,  which 
is  converted  into  nitrate  by  saturation 
with  nitric  acid,  evaporation,  and  crys- 
tallization. The  nitrate  is  used  for  fed 
light  in  theatres. 

CEMENTATION  implies  the  imbed- 
ding of  any  solid  substance  in  a  pulve- 
rulent matter,  and  exposing  both  to  ig- 
nition in  an  earthen  or  metallic  case. 
Iron  is  thus  cemented  with  charcoal  to 
form  steel,  and  bottle-glass  with  gypsum 
powder,  or  sand,  to  form  Reaumur's 
porcelain. 

CEMENTS.  Substances  capable  of 
taking  the  liquid  form,  and  of  being  in 
that  state  applied  between  the  surfaces 
of  two  bodies,  so  as  to  unite  them  by 
solidifying.  They  may  be  divided  into 
two  classes,  those  which  arc  applied 
through  the  agency  of  a  liquid  men- 
struum, such  as  water,  alcohol,  or  oil, 
and  those  which  arc  applied  by  fusion 
with  heat. 

The  diamond  cement  for  uniting  broken 
pieces  of  china,  glass,  &c,  which  is  sold 
as  a  secret  at  an  absurdly  dear  price, 


is  composed  of  isinglass  soaked  in  water 
till  it  becomes  soft,  and  then  dissolved 
in  proof  spirit,  to  which  a  little  gum 
resin,  ammoniac,  or  galbanum,  and  resin 
mastic  are  added,  each  previouslv  dis- 
solved in  a  minimum  of  alcohol.  When 
to  be  applied,  it  must  be  gently  heated 
to  liquefy  it ;  and  it  should  be  kept  for 
use  in  a  well-corked  vial.  A  glass  stop- 
per would  be  apt  to  fix  so  as  not  to  be 
removable.  This  is  the  cement  cm- 
ployed  by  the  Armenian  jewellers  in 
Turkey  for  glueing  the  ornamental  stones 
to  trinkets  of  various  kinds.  When  well 
made  it  resists  moisture. 

Shellac  dissolved  in  alcohol,  or  in  a 
solution  of  borax,  forms  a  pretty  good 
cement.  White  of  egg  alone,  or  mixed 
with  finely  sifted  quicklime,  will  answer 
for  uniting  objects  which  are  not  ex- 
posed to  moisture.  The  latter  combina- 
tion is  very  strong,  and  is  much  em- 
ployed for  joining  pieces  of  spar  and 
marble  ornaments.  A  similar  compo- 
sition is  used  by  copper-smiths  to  secure 
the  edges  and  rivets  of  boilers ;  only 
bullock's  blood  is  the  albuminous  matter 
used  instead  of  white  of  egg.  Another 
cement  in  which  an  analogous  substance, 
the  curd  or  caseum  of  milk  is  employed, 
is  made  by  boiling  slices  of  skim-milk 
cheeses  into  a  gluey  consistence  in  a 
great  quantity  of  water,  and  then  incor- 
porating it  with  quicklime  on  a  slab  with 
a  muller,  or  in  a  marble  mortar.  When 
this  compound  is  applied  warm  to  broken 
edges  of  stoneware,  it  unites  them  very 
firmly  after  it  is  cold. 

A  cement  which  gradually  indurates 
to  a  stony  consistence  may  be  made  by 
mixing  20  parts  of  clean  river  sand,  two 
of  litharge,  and  one  of  quicklime,  into  a 
thin  putty  with  linseed  oil.  The  quick- 
lime may  be  replaced  with  litharge. 
When  this  cement  is  applied  to  mend 
broken  pieces  of  stone,  as  steps  of  stairs, 
it  acquires  after  some  time  a  stony  hard- 
ness. A  similar  composition  has  been 
applied  to  coat  over  brick  walls,  under 
the  name  of  mastic. 

The  iron-rust  cement  is  made  of  from 
50  to  100  parts  of  iron  borings,  pounded 
and  sifted,  mixed  with  one  part  of  sal- 
ammoniac  ;  and  when  it  is  to  be  applied, 
moistened  with  as  much  water  as  will 
give  it  a  pasty  consistency.  Formerly 
flowers  of  sulphur  were  used,  and  much 
more  sal-ammoniac  in  making  this  ce- 
ment, but  with  decided  disadvantage, 
as  the  union  is  effected  by  the  oxydize- 
ment,  consequent  expansion,  and  solidi- 


84 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


fication  of  the  iron  powder,  and  any  he- 
terogeneous matter  obstructs  the  effect. 
The  best  proportion  of  sal-ammoniac  is, 
I  believe,  one  per  cent  of  the  iron  bor- 
ings. Another  composition  of  the  same 
kind  is  made  by  mixing  4  parts  of  fine 
borings,  or  filings  of  iron,  2  parts  of 
potter's  clay,  and  1  part  of  pounded  pot- 
sherds, and  making  them  into  a  paste 
with  salt  and  water.  When  this  cement 
is  allowed  to  concrete  slowly  on  iron 
joints,  it  becomes  very  hard. 

For  making  architectural  ornaments  in 
relief,  a  moulding  composition  is  formed 
of  chalk,  glue,  and  paper  paste.  Even 
statues  have  been  made  with  it,  the 
paper  aiding  the  cohesion  of  the  mass. 

Mastics  of  a  resinous  or  bituminous 
nature  which  must  be  softened  or  fused 
by  heat  are  the  following : 

Mr.  S.  Varley's  consists  of  sixteen 
parts  of  whiting  sifted  and  thoroughly 
dried  by  a  red  heat,  adding  when  cold 
a  melted  mixture  of  16  parts  of  black 
resin  and  1  of  bees'-wax,  and  stirring 
well  during  the  cooling. 

Mr.  Singer's  electrical  and  chemical 
apparatus  cement  consists  of  5  lbs.  of 
resin,  1  of  bees'-wax,  1  of  red  ochre, 
and  two  table-spoonsful  of  Paris  plaster, 
all  melted  together.  A  cheaper  one  for 
cementing  voltaic  plates  into  wooden 
troughs  is  made  with  6  lbs.  of  resin,  1 
pound  of  red  ochre,  i  of  a  pound  of 
plaster  of  Paris,  and  j  of  a  pound  of  lin- 
seed oil.  The  ochre  and  the  plaster  of 
Paris  should  be  calcined  beforehand,  and 
added  to  the  other  ingredients  in  their 
melted  state.  The  thinner  the  stratum 
of  cement  that  is  interposed,  the  strong- 
er, generally  speaking,  is  the  junction. 

Boiled  linseed  oil  and  red  lead  mixed 
gether  into  a  putty  are  often  used  by  cop- 
persmiths and  engineers,  to  secure  joints. 
The  washers  of  leather  or  cloth  are  smear- 
ed with  this  mixture  in  a  pasty  state. 

The  resin  mastic  alone  is  sometimes  to- 
used  by  jewellers  to  cement  by  heat  ca- 
meos of  white  enamel  or  colored  glass  to 
a  real  stone,  as  a  ground  to  produce  the 
appearance  of  an  onyx.  Mastic  is  like- 
wise used  to  cement  false  backs  or 
doublets  to  stones,  to  alter  their  hue. 

Melted  brimstone,  either  alone,  or 
mixed  with  resin  and  brick  dust,  forms 
a  tolerably  good  and  very  cheap  cement. 

Plumber's  cement  consists  of  black 
resin  one  part,  brick  dust  two  parts,  well 
incorporated  by  a  melting  heat. 

The  bituminous  or  black  cement  for 
bottle  corks,  is  pitch  hardened  by  resin 
and  brick  dust.     The  following  makes  a 


good  cement  for  mastic  works :  mix  50 

parts  of  silicious  sand,  50  parts  of  lime 

marl,  or  pulverized  brown  sand  stone 

|  and  8  parts  of  litharge.    When  the  ce- 

!  ment  is  used  it  is  to  be  ground  up  with 

j  linseed  oil. 

An  excellent  cement  for  resisting  mois- 
J  ture  is  made  by  incorporating  thoroughly 
!  8  parts  of  melted  glue,  of  the  consistence 
I  used  by  carpenters,  with  4  parts  of  lin- 
j  seed  oil,  boiled  into  varnish  with  litharge. 
]  This  cement  hardens  in  about  forty-eight 
i  hours,  and  renders  the  joints  of  wooden 
!  cisterns  and  casks  air  and  water  tight. 
|  A  compound  of  glue  with  one-fourth  its 
i  weight  of  Venice  turpentine,  made  as 
|  above,  serves  to  cement  glass,  metal,  and 
j  wood,  to  one  another.  Fresh  made 
I  cheese-curd,  and  old  skim-milk  cheese, 
j  boiled  in  water  to  a  slimy  consistence, 
!  dissolved  in  a  solution  of  bicarbonate  of 
|  potash,  are  said  to  form  a  good  cement 
;  for  glass  and  porcelain.  The  gluten  of 
I  wheat,  well  prepared,  is  also  a  good 
;  cement.  White  of  eggs,  with  flour  and 
;  water  well  mixed,  and  smeared  over  linen 
I  cloth,  forms  a  ready  lute  for  steam  joints 
in  small  apparatus. 

White  lead  ground  upon  a  slab  with 
linseed  oil  varnish,  and  kept  out  of  con- 
tact of  air,  affords  a  cement  capable  of 
repairing  fractured  bodies  of  all  kinds. 
It  requires  a  few  weeks  to  harden.  When 
stone  and  iron  are  to  be  cemented  toge- 
ther, a  compound  of  equal  parts  of  sul- 
phur with  pitch  answers  very  well. 
For  hydraulic  cement,  see  Mortar. 
Mr.  Seating,  of  London,  has  patented 


a  mode  of  combining  ervpsum  or  other 
cement. 


calcareous  substances  with  borax,  for  a 


Separate  solutions  of  borax  and  crude 
tartar  are  made,  and  then  mixed :  cal- 
cined gypsum  is  then  added  in  lumps  to 
the  liquor,  and  allowed  to  remain  till  it 
has  absorbed  all  it  will  take  up.  It  is 
then  taken  out  and  heated  in  an  oven : 
again  put  in  the  solution  and  afterwards 
burned  :  when  it  is  fit  for  use. 

CENTIGKADE  DIVISION.  The  di- 
vision into  grades  or  degrees  by  hun- 
dredth parts.  A  unity  of  any  denomi- 
nation being  divided  into  100  equal 
parts,  forms  a  centigrade  scale ;  but  the 
term  most  frequently  occurs  in  scientific 
works,  in  reference  to  the  French  divi- 
sion of  the  scale  of  the  thermometer. 
The  fixed  points  of  the  thcrmometric 
scale  are  the  points  at  which  water  freezes 
on  the  one  hand,  and  boils  on  the  other ; 
the  distance  between  these  two  points 
being  divided  into  100  degrees,  the  cen- 


cha] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


85 


tigrade  scale  is  formed.  In  Fahrenheit's 
scale,  which  is  usually  applied  to  the 
thermometer  in  this  country,  the  same 
distance  is  divided  into  180  degrees  ;  a 
degree  of  the  centigrade  scale  is  there- 
fore greater  than  a  degree  of  Fahrenheit 
in  the  proportion  of  180  to  100,  or  of  9  to 
5.  Any  number  of  degrees,  therefore, 
on  the  centigrade  scale,  being  multiplied 
by  9  and  divided  by  5,  will  give  the  equi- 
valent number  of  degrees  of  Fahrenheit. 
But  in  comparing  temperatures  express- 
ed by  the  two  scales,  it  is  necessary  to 
recollect  that  the  zero  of  Fahrenheit's 
scale  is  not  placed  at  the  freezing  point, 
but  82°  below  it.  An  example  will  best 
show  how  this  is  to  be  taken  into  ac- 
count. Let  it  be  required  to  express  on 
Fahrenheit's  scale  the  temperature  corre- 
sponding to  10°  centigrade.  Here  10  X 
9  -r  5  =  18 ;  to  this  add  82,  and  we  have 
18  -+-  82  =  50  ;  so  that  10  degrees  of  the 
centigrade  scale  correspond  to  50  degrees 
of  Fahrenheit's. 

CENTK1FUGAL  FORCE.  The  force 
by  which  a  body  in  rotation  tends  to  re- 
cede from  the  centre  of  motion  :  Centri- 
petal Force,  that  by  which  a  body  in 
motion  is  urged  towards  a  centre,  and 
compelled  to  describe  a  curve  instead  of 
a  straight  line. 

CENTRIFUGAL  MACHINE.  A  ma- 
chine moved  by  the  centrifugal  force  of 
water  ;  frequently  called  from  its  inven- 
tor, Barker's  Mill.  It  consists  of  a  hol- 
low metal  cylinder  or  pipe  of  metal  placed 
upright,  and  resting  on  a  pointed  steel 
pivot  at  A.  The  pipe  is  widened  or  ex- 
tended into  a  funnel  shape  at  the  top  B, 
and  is  kept  in  its  position  by  a  vertical 
steel  axis  C  D,  passing  through  a  frame 
at  the  top.  Towards  "the  lower  extrem- 
ity, two  or  more  small  pipes  A  E,  A  F, 
with  closed  external  ends,  are  inserted  at 
right  angles  to  the  axis.  In  the  side  of 
each  of  these  an  orifice  is  made  as  near 
as  possible  to  the  end,  and  on  opposite 
sides,  so  that  water  from  them  may 
spout  horizontally  in  opposite  directions. 
Water  is  conveyed  into 
the  funnel  at  the  top, 
through  the  pipe  G,  in 
such  quantities  that 
the  tube  is  kept  con- 
stantly full,  while  the 
discharge  is  going  on 
at  the  orifice  "near  the 
extremities  of  the  ho- 
rizontal pipes.  In  this 
state  of  things  the  re- 
sistance or  reaction  ge- 
nerated by  the  water 


issuing  from  the  side-holes  is  such  as  to 
throw  the  vertical  pipe,  with  its  arms 
and  axis,  into  rapid  rotatory  motion ;  and 
this  axis  may  communicate  its  motion  or 
power  to  wheelwork  or  machinery,  or  to 
a  mill-stone  connected  with  its  upper 
end.  A  machine  of  the  same  construc- 
tion, but  having  the  arms  at  the  upper 
end,  and  turned  rapidly  by  means  of  a 
wheel  and  pinion,  was  invented  by  a  Mr. 
Erskine  for  raising  water.  Centrifugal 
Machine  is  also  used  synonymously  with 
Whirling  Machime. 

CERAS1N.  Cherry-tree  gum  :  a  name 
given  to  gums  which  swell  and  soften, 
but  do  not  readily  dissolve  in  water. 

CERATE.  An  ointment  made  of  wax 
and  oil,  or  spermaceti. 

CERATR1N.  The  bitter  principle  of 
Iceland  moss. 

CEREAL  GRASSES.  Those  which 
give  flour  fit  for  bread  :  such  as  corn, 
wheat,  rye,  barley,  oats,  rice,  and  millet. 

CERINE.  One  of  the  principles  of 
wax  :  soluble  in  alcohol ;  there  is  nearly 
80  per  cent,  of  it  in  bees-wax.  It  is  white, 
melts  at  134°,  and  is  carbonized  by  sul- 
phuric acid.  Cork  grated  and  boiled  in 
alcohol,  furnishes  a  substance  resembling 
cerine. 

CERITE.  A  siliceous  oxyde  of  cerium. 

CERIUM.  A  metal  named  after  the 
planet  Ceres,  and  discovered  in  1803  by 
Hisinger  and  Berzclius  in  a  Swedish  mi- 
neral termed  cerite,  and  since  found  by 
Dr.  Thompson  in  Allanite,  a  mineral 
from  Greenland.  It  is  said  to  be  a  white 
brittle  metal,  very  difficult  of  fusion,  and 
volatile  when  intensely  heated ;  but  we 
are  scarcely  acquainted  with  it  in  its 
metallic  state.  Its  equivalent  number 
appears  to  be  48,  on  the  hydrogen  scale. 

CEROSTROTUM,  or  CESTROTUM. 
A  species  of  encaustic  painting,  executed 
chiefly  on  horn  or  ivory  with  a  particular 
sort  of  stylum  called  a  cestrum,  which 
was  pointed  at  one  end  and  flat  on  the 
other.  The  cestrum  was  heated,  and 
with  it  the  lines  of  the  subject  were 
burnt  in,  and  wax  introduced  into  the 
furrows  made  by  the  heated  instrument. 
Doors  Avere  sometimes  ornamented  with 
this  species  of  painting. 

CERULIN.  Indigo  dissolved  in  sul- 
phuric acid. 

CERUSE.    Carbonate  of  lead. 

CETI NE.    Pure  spermaceti . 

CHABAZITE.    A  variety  of  Zeolite. 

CHAFF.  The  husk  or  withered  calyx 
of  grasses,  and  more  especially  of  the 
bread  corns.  The  term  is  also  applied  to 
straw  or  hay  cut  into  very  short  lengths, 


86 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CHA 


and  used  for  mixing  with  corn,  roots,  or 
other  food  for  horses  or  cattle.  This 
kind  of  chaff,  in  greater  lengths,  is  also 
used  for  mixing  with  mortar  on  some 
parts  of  the  Continent,  more  particularly 
m  Germany  and  Kussia ;  and  it  is  used 
as  a  substitute  for  hair  in  making  plaster 
for  rooms.  Both  stubble  and  cut  hay 
were  used  by  the  ancient  Egyptians  in 
making  bricks. 

CHAIN  WORK.  A  peculiar  style  of 
fabric  to  which  hosiery  and  tambouring 
belong. 

RAIL-CHAIR.  Mr.  Van  Anden  has 
secured  a  patent  for  a  wrought  iron  chair, 
which  displays  much  ingenuity,  and  is 
an  useful  invention.  Figure,  ISo.  1,  is  a 
view  of  the  rail  secured  in  the  chair,  and 
figure,  No.  2,  is  a  view  of  the  chair  it- 
self. 

Fie.  i. 


D  E  are  the  sections  of  two  rails  placed 
together  and  secured  at  the  joint  on  the 
chair  by  the  jaws,  B  B.  The  chair  is 
bolted  down  by  the  spikes,  C  C.  In  fig. 
2  the  chair  is  represented  as  made  of  a 
single  block  or  plate,  A,  of  wrought  iron. 

The  machine  takes  the  bar  of  iron  as  it 
comes  from  the  rolls — cuts  it — forms  the 
jaws,  punches  the  holes,  and  completes 
the  chair  at  a  single  blow.  The  chair  is 
set  in  its  proper  place  on  the  track, 
spiked  down,  and  the  ends  of  the  two 
rails  brought  together  within  the  jaws, 

Fig.  2. 


as  represented  in  fig.  1.  The  jaws  are 
then  hammered  down  snug  upon  the 
bed  plate  of  the  rails,  thus  securing  them 
in  the  most  perfect  manner.  The  advan- 
tages of  the  wrought  over  the  cast  iron 
rail  chair  admits  of  but  little  argument. 

CHALCEDONY.  A  semi-transparent 
silicious  mineral,  apparently  formed  by 
the  infiltration  of  silicious  matters  origin- 
ally in  a  state  of  solution.  It  is  of  various 
colors,  and  often  banded.  The  finest 
specimens  are  said  to  have  been  found  at 
Chalcedon  in  Asia. 

CHALCOGRAPHY.  The  art  of  en- 
graving on  brass  and  copper. 

CHALK.  Earthy  carbonate  of  lime. 
(See~Liuv.) 

CHALYBEATE.  Medicines  and  min- 
eral waters  containing  iron  are  called 
chalvbeates. 

CHAMELEON  MINERAL.  A  com- 
pound of  manganesic  acid  and  potash, 
which  presents  a  variety  of  tints  when 
dissolved  in  water.  As  it  has  of  late 
been  largely  employed  for  whitening  tal- 
low, palm  oil,  and"  decoloring  other  or- 
ganic matters,  it  merits  description.  It 
exists  in  two  states ;  one  of  which  is 
called  by  chemists  the  manganate  of  pot- 
ash, and  the  other  the  oxymanganate ; 
denoting  that  the  first  is  a  compound  of 
manganic  acid  with  potash,  and  that  the 
second  is  a  compound  of  oxymanganic 
acid  with  the  same  base.  They  are  both 
prepared  in  nearly  the  same  way  •  the 
former  by  calcining  together,  at  a  red  heat, 
in  a  covered  crucible,  a  mixture  of  one  part 
of  the  black  peroxide  of  manganese  with 
three  parts  of  the  hydrate  of  potash  (the 
fused  potash  of  the  apothecary).  The 
mass  is  of  a  green  color  when  cold.  It  is 
to  be  dissolved  in  cold  water,  and  the 
solution  allowed  to  settle,  and  become 
clear,  but  by  no  means  filtered  for  fear  of 
the  decomposition  to  which  it  is  very 
prone.  When  the  decanted  liquid  is 
evaporated  under  the  exhausted  receiver 
of  an  air  pump,  over  a  surface  of  sul- 
phuric acid,  it  affords  crystals  of  a  beau- 
tiful green  color,  which  should  be  laid  on 
a  clean  porous  brick  to  drain  and  dry. 
They  may  be  preserved  in  dry  air,,  but 
should  be  kept  in  a  well-corked  bottle. 
They  are  decomposed  by  water,  but  dis- 
solve in  weak  water  of  potash.  On  dilut- 
ing this  much,  decomposition  of  the  salt 
ensues,  with  all  the  chameleon  changes 
of  tint ;  red,  blue,  and  violet.  Sometimes 
a  green  solution  of  this  salt  becomes  red 
on  being  heated,  and  preserves  this  co- 
lor even  when  cold,  but  resumes  its  green 
hue  the  moment  it  is  shaken.    The  ori- 


ohe] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


87 


ginal  calcined  mass,  in  being  dissolved, 
always  deposits  a  considerable  quantity  of 
a  brown  powder,  which  is  a  compound  of 
the  acid  and  peroxide  of  manganese  com- 
bined with  water.  Much  of*  the  potash 
remains  unchanged,  which  may  be  reco- 
vered. 

A  permanent  oxymanganic  salt  may  be 
made  as  follows  : — Melt  chlorate  of  pot- 
ash over  a  spirit  lamp,  and  throw  into  it 
a  few  pieces  of  hydrate  of  potash,  which 
immediately  dissolve,  and  lorm  a  limpid 
liquid.  When  peroxide  of  manganese  in 
fine  powder  is  gradually  introduced  into 
that  melted  mixture,  it  immediately  dis- 
solves, with  the  production  of  a  rich 
green  color.  After  adding  the  manganese 
in  excess,  the  whole  is  to  be  exposed  to  a 
gentle  red  heat,  in  order  to  decompose 
the  residuary  chlorate  of  potash.  It  is 
now  a  mixture  of  manganate  of  potash, 
chloride  of  potassium  and  peroxide  of 
manganese.     It  forms  with  water  a  deep 

freen-colored  solution,  which  when 
oiled  assumes  a  fine  red  color,  in  conse- 
quence of  its  becoming  an  oxymanganate, 
and  it  ought  to  be  decanted  off  the  sedi- 
ment while  hot.  By  cooling,  and  still 
more  after  further  evaporation,  the  oxy- 
manganate of  potash  separates  in  crystals 
possessed  of  great  lustre ;  but  toward  the 
end  colorless  crystals  of  chloride  of  potas- 
sium. 

CHARCOAL.  A  form  of  carbon,  ob- 
tained by  burning  wood  with  the  imper- 
fect access  of  air,  or  by  heating  or  dis- 
tilling it  in  iron  cylinders  so  constructed 
as  to  allow  of  the  collection  of  the  vola- 
tile products ;  among  which  are  tar, 
and  pyroligneous  acid,  which  is  impure 
vinegar.  Charcoal,  exclusive  of  its  im- 
portant use  as  a  fuel,  is  possessed  of  some 
curious  and  valuable  properties.  It  is  a 
very  bad  conductor  of  heat ;  and  hence 
powdered  charcoal  is  used  to  surround 
tubes  and  vessels  which  are  required  to 
retain  their  heat.  It  is  not  injured  by 
air  and  moisture  :  hence  stakes  and  piles 
are  superficially  charred  to  preserve  them. 
It  is  infusible ;  and  provided  air  be  care- 
fully excluded,  it  undergoes  no  change 
in  most  intense  heats.  It  absorbs  air 
and  moisture,  and  also  the  coloring  and 
odoriferous  parts  of  many  animal  and  ve- 
getable substances.  Tainted  flesh  and 
putrid  water  are  thus  sweetened  by  the 
action  of  powdered  charcoal,  especially 
by  what  is  called  animal  charcoal,  ob- 
tained by  burning  bone,  or  the  clippings 
of  hides,  leather,  ~&c.  Colored  vegetable 
solutions  filtered  through  well  burned 
charcoal  are  materially  decolored  by  it : 


when  burned  in  oxygen  or  air,  it  is  con- 
verted into  carfomic  acid.  {See  Diamond 
and  Carbon.)  Common  charcoal,  in- 
tended merely  for  fuel,  is  prepared  by 
cutting  pieces  of  wood  from  1  inch  to  3 
inches  in  diameter,  into  lengths  of  from 
1  foot  to  3  feet,  forming  them  into  a  coni- 
cal pile,  and  covering  them  with  turf  or 
clay ;  leaving  two  or  three  small  holes, 
close  to  the  ground,  for  lighting  the 
wood,  and  boring  through  the  turf  m  the 
upper  part  of  the  cone  a  few  other  small 
holes  for  the  escape  of  the  smoke.  The 
pile  being  lighted  at  the  several  holes 
along  the  bottom,  continues  burning 
with  a  slow  smouldering  flame  for  a  week 
or  two,  and  is  allowed  to  cool  before  the 
turf  is  removed.  In  the  case  of  very 
high  winds,  the  holes  to  the  windward, 
are  stopped,  to  prevent  combustion  from 
going  on  with  too  great  rapidity.  Char- 
coal obtained  by  distilling  beech-  ivood, 
log-wood,  willow,  and  other  woods  which 
are  free  from  resin,  is  called  cylinder 
charcoal.  The  charcoal  employed  in  the 
manufacture  of  gunpowder  is  now  always 
so  prepared. 

It  is  not,  however,  by  any  means  as 
good  as  that  prepared  by  the  burning  of 

Eeat  or  turf.  More  charcoal  is  obtained 
y  the  slow  combustion  of  the  wood  than 
by  the  quick.  The  quantity  of  charcoal 
obtainable  from  wood  varies  from  12  to 
25  per  cent. 

Animal  charcoal  is  superior  in  its  de- 
colorizing power  to  vegetable  charcoal. 
In  filtering  ale  through  it,  it  was  found  to 
abstract  all  the  bitter  principle ;  it  has 
also  the  property  of  separating  sulphate 
of  quina,  many  salts  of  the  alkaloids,  as 
well  as  other  saline  matters  from  their 
solutions. 

Its  absorbing  power  over  gases  is  great- 
est when  it  is  fresh.  It  acts  with  differ- 
ent energy  on  different  gases  ;  thus,  one 
cubic  inch  of  charcoal  will  absorb  of 

Ammoniacal  Gas 90  cubic  inches. 

Muriatic  Acid 85  " 

Sulphurous  Acid    65  " 

Sulphuretted  Hydrogen   ..55  " 

Carbonic  Acid 35  "    , 

Oyxgen 9i  " 

Hydrogen \\  " 

Hence  the  great  value  of  charcoal 
thrown  into  cesspools  and  privies,  to  ab- 
sorb odors  ;  hence  its  use,  added  to  gua- 
na, fcecal  matter,  urine,  or  any  substance 
giving  off  gases  valuable  for  growth  of 
vegetation.  Its  chief  value  as  a  manure 
depends  on  this  property.  Charcoal  is 
occasionally  used  as  a  polishing  powder. 

CHAKRED  WOOD.   Wood,  the  outer 


88 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CHA 


surface  of  which  has  been  carbonized  by 
burning,  in  order  to  preserve  it  from  de- 
cay when  it  is  buried  in  the  soil. 

CHARRING  OF  POSTS.  The  prac- 
tice of  carbonizing  by  burning  that  por- 
tion of  the  surface  of  wooden  posts 
which  is  to  be  inserted  in  the  ground. 
The  object  is  to  prevent  the  posts  from 
decaying,  more  especially  at  the  surface 
of  the  ground,  or,  as  the  common  phrase 
is,  between  wind  and  water.  The  prac- 
tice is  common  in  most  parts  of  Europe, 
and  even  in  Russia  and  Sweden,  though 
timber  is  there  so  abundant.  Dipping 
the  ends  of  the  timber  in  oil  of  vitriol, 
diluted  with  four  parts  of  water,  chars 
the  outside  of  the  wood,  and  answers 
verv  well  for  stakes  and  fence  wood. 

CHASING.  Embossing  in  metal.  The 
work  to  be  embossed  as  bassi  relievi  are 
punched  out  from  the  back,  and  then 
cut  on  steel  blocks  or  puncheons,  and 
cleared  with  small  chisels  or  gravers. 

CHEESE  consists  of  the  curd  of 
milk  mixed  with  some  of  the  fatty  mat- 
ter and  sugar  of  milk.  Difference  in  the 
quality  of  the  milk  and  the  dairy  man- 
agement determines  endless  variety  in 
the  produce.  To  separate  the  curd  or 
casein  it  is  necessary  to  acidify  the  milk, 
and  adopt  such  other  means  as  will  sepa- 
rate the  curd  rapidly  and  effectually. 
The  liquid  portions  have  then  to  be 
expressed  from  the  cake  of  curd.  Any 
acid  will  coagulate  milk,  but  rennet  is  the 
acidulous  substance  always  used.  Before 
adding  rennet  new  milk  should  be  heated 
up  to  95°  F. ;  skim  milk  not  so  high. 
This  separates  the  curd  in  a  tougher 
and  harder  state.  The  milk  should  not  be 
fire  fanged  in  the  heating.  A  naked  fire 
is  objectionable  ;  immersing  the  milk 
vessel  in  a  larger  one  containing  boiling 
water  is  the  proper  mode.  Vessels  with 
a  double  bottom  might  be  used  for  this 
purpose.  The  rennet  ought  never  to  be 
putrid,  nor  added  in  too  large  quantity, 
ior  then  the  curd  is  too  tough.  If  too 
little,  time  islost.  When  acids,  as  vinegar, 
are  used  instead  of  rennet,  the  cheese  is 
apt  to  have  their  flavor. 

The  acid,  formed  by  the  addition  of  the 
rennet,  should  be  separated  slowly  from 
the  whey?  for  if  done  hastily,  the  fat  of 
the  milk  is  squeezed  out,  and  the  cheese 
is  poorer.  The  whey  should,  however, 
be  completely  removed,  for  as  it  contains 
sugar  and  lactic  acid,  if  left  behind,  fer- 
mentation will  set  in.  Curd-mills  and 
cheese-presses  arc  used  to  effect  this  re- 
moval. 

The  preservation  of  the  fresh  cake  de- 


pends on  the  purity  of  the  salt,  and  the 
mode  of  applying  it. 

Cheese  is  then  colored  sometimes  by 
saffron,  but  chiefly  by  annotto,  in  the 
proportion  of  i  an  oz.  to  60  lbs.  of  cheese ; 
sometimes  the  marigold  and  carrot  are 
boiled  in  milk,  and  used  as  coloring. 

In  milk  of  average  quality,  there  is 
from  4  to  5  per  cent,  of  pure  casein,  which, 
if  all  extracted,  would  give,  according  to 
Professor  Johnston,  6  to  7  lbs.  of  skim 
milk  cheese,  or  9  to  10  lbs.  pure  new  milk 
cheese,  in  every  100  lbs.  of  milk ;  and  on 
an  average,  8  to  10  lbs.  of  good  milk  in 
summer,  will  yield  1  lb.  of  whole  milk 
cheese.  The  following  abstract  of  Euro- 
pean cheeses,  taken  from  Brandos  Ency- 
clopedia, may  be  interesting : 

"  The  following  are  the  principal  British 
cheeses :  Brickhat,  formed  of  new  milk 
and  cream,  chiefly  in  "Wiltshire,  in  the 
autumn,  and  sold  in  little  square  pieces 
about  the  size  of  brickbats.  Cheddar, 
round  thick  cheeses,  weighing  about  150 
or  200  lbs.,  with  a  spongy  appearance,  and 
the  eyes  or  vesicles  filled  with  a  rich  oil. 
Cheshire,  large  round  thick  cheeses,  com- 
monly weighing  from  100  to  200  lbs.  each, 
— solid,  homogeneous,  and  dry  and  friable 
rather  than  viscid.  They  are  made  from 
the  whole  of  the  milk  and  cream,  the 
morning's  milk  being  mixed  with  that  of 
the  preceding  evening  previously  warmed. 
Derbyshire  is  a  small  white  rich  cheese. 
Bunfop,  originally  made  in  Ayrshire,  but 
now  general  throughout  Scotland,  is 
large,  round,  white,  buttery,  and  weighs 
from  30  to  60  lbs.  This  and  the  Derby- 
shire cheese  are  very  much  alike  in  form, 
color,  and  flavor.  Gloucester,  large,  round, 
and  mild;  buttery  rather  than  friable. 
There  are  two  kinds,  the  single  and  dou- 
ble Gloucester :  the  single  is  made  of  the 
milk  deprived  of  about  half  the  cream, 
and  the  double  of  the  milk  with  the  whole 
of  the  cream.  Green  or  Sage  cheese  may 
be  made  of  any  of  the  other  kinds,  by 
mixing  the  milk  before  it  has  curdled 
with  a  decoction  of  sage  leaves,  among 
which  some  put  a  few  flowers  of  marigold 
and  leaves  of  parsley.  In  the  Highlands 
of  Scotland  the  leaves  or  seeds  of  lovage 
are  added  to  the  sage,  which  communi- 
cate a  very  strong  "flavor.  Lincolnshire 
is  made  of  new  milk  and  cream;  it  is 
quite  soft,  not  above  2  inches  thick,  and 
will  not  keep  more  than  two  or  three 
months.  Norfolk,  the  weight  is  generally 
from  30  to  50  pounds ;  the  curd"  is  dyed 
yellow  with  arnotto  or  saffron,  and  though 
not  a  rich  cheese,  it  is  considered  a  good 
keeper.     Soft  or  Slipcoat  is  a  small,  soft, 


che] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


89 


rich  cheese,  which  might  almost  be  mis- 
taken for  butter,  if  it  were  not  white,  and 
which  must  be  eaten  in  a  week  or  two 
after  making.  Stilton,  so  named  from 
the  town  m  Huntingdonshire  where  it 
was  first  brought  into  notice,  but  which 
is  made  principally  in  Leicestershire.  It 
is  solid,  rich,  buttery,  and  white,  and,  un- 
like all  the  other  cheeses  which  have  been 
mentioned,  it  is  twice  as  high  as  it  is 
broad.  It  is  much  improved  by  keeping, 
and  is  seldom  used  before  it  is  two  years 
old.  It  is  the  dearest  of  all  English 
cheeses,  the  price  being  generally  to~that 
of  Chester  as  2  to  1,  or  2  to  lj.  In  order 
to  induce  premature  decay  and  the  conse- 
quent appearance  of  age  in  these  cheeses, 
it  is  said  the  makers  sometimes  bury  them 
in  masses  of  fermenting  straw.  Cotten- 
ham,  so  named  from  a  town  in  Cambridge- 
shire ;  it  differs  chiefly  from  the  cream 
cheese  of  Stilton  in  being  flat,  broader, 
and  superiorly  flavored.  The  flavor  is 
said  to  be  owing  to  the  rich  grasses  which 
grow  on  the  fens.  Suffolk,  or  skim-milk, 
is  round  and  thin,  weighing  from  25  to 
80  lbs.  each,  and  is  the  best  keeping 
cheese  made  in  England.  Wiltshire  re- 
sembles the  Cheshire,  but  is  poorer,  and 
of  inferior  flavor.  It  is  apt  to  become 
scurfy,  to  prevent  which  it  is  generally 
coated  over  with  red  paint.  Yorkshire, 
or  cream  cheese,  is  the  same  as  the  slip 
coat  cheese,  already  mentioned. 

European  Cheeses. — The  most  remark- 
able ot  these  are  the  following :  Parmesan 
is  chiefly  made  at  Parma  and  other  places 
in  Lombardy,  of  the  curd  of  skimmed 
milk  hardened  by  heat.  Its  flavor  is  said 
to  be  owing  to  the  rich  pastures  of  that 
part  of  Italy,  where  all  plants,  from  the 
greater  quantity  of  bright  sunshine  than 
in  Britain,  have  doubtless  their  aromatic 
properties  greatly  increased.  Siviss  cheese 
is  of  various  kinds ;  but  the  chief  sorts 
are  the  Gruyere  or  Jura  cheese,  and 
Schabzieger  or  green  cheese :  the  last  is 
flavored  with  the  seeds  and  leaves  of  the 
melilot  (Mdilotis  officinalis).  German 
cheeses  are  of  different  kinds ;  but  none 
are  celebrated,  unless  we  except  that  of 
Westphalia,  which  is  made  up  into  round 
balls  or  short  cylinders,  under  a  pound 
weight  each.  The  peculiar  flavor  which 
this  cheese  acquires,  arises  from  the  curd 
being  allowed  to  become  putrid  before  it 
is  compressed.  In  Holland  very  good 
cheese  is  made,  particularly  the  Edam  and 
Gouda  cheeses  :  the  former  is  very  salt, 
and  keeps  well  at  sea.  In  many  parts  of 
the  Continent,  and  even  in  the  interior  of 
Poland  and  Russia,  there  are  imitations 


of  English  cheese  made ;  but  what  may 
be  called  the  indigenous  cheese  of  the 
Russian  empire  is  nothing  more  than 
salted  curd  put  into  a  bag  and  powerfully 
pressed,  and  taken  to  market  as  soon  as 
it  is  made,  in  the  same  manner  as  butter 
is.  In  some  places,  instead  of  a  press, 
the  whey  is  forced  out  of  the  curd  by 
putting  it  into  a  long  cloth  midway  be- 
tween the  two  ends,  while  a  person  at 
each  end  twists  the  cloth  in  an  opposite 
direction,  and  thus  wrings  out  the  whey. 
In  some  miserable  Russian  villages  the 
curd  is  exposed  for  sale  in  small  lumps, 
retaining  the  marks  of  the  fingers,  which 
shows  that  no  other  pressure  has  been 
employed  than  what  can  be  given  with 
the  hand.  In  France  the  Roquefort 
cheese  is  the  most  esteemed,  and  next 
that  of  Neufchatel.  The  former  some- 
what resembles  Stilton,  but  is  much  in- 
ferior, and  the  latter  is  a  cream  cheese, 
seldom  exceeding  a  quarter  of  a  pound 
in  weight. 

The  cheese  manufacture  is  a  large  and 
important  one  in  the  Northern  and  West- 
ern States,  and  the  exportation  is  great 
and  increasing.  New  York  is  the  chief 
station  for  export,  and  the  quantity  which 
reaches  that  city  may  be  estimated  from 
the  following  abstract  from  the  Patent- 
Office  Report  for  1847. 

The  Albany  Journal  gives  the  following 
statement  of  the  amount  of  Cheese  re- 
ceived at  Albany  and  Troy  during  the 
past  twelve  years : 

1836,  pounds, 14,060,000 

1S37,      "       15,500,000 

1838,  "   13,810,000 

1839,  "   14,530,000 

1840,  "   18,S20,000 

1841,  "   14,170,000 

1842,  "   19,004,000 

1843,  "   24,331,000 

1844,  "   26,677,500 

1845,  "   27.542,861 

1846,  "   35,560,180 

1847,  "   40,S14,000 

This  last  having  a  value  of  $2,860,854. 
The  importation  of  cheese  into  Great 

Britain  is  larger  than  that  of  butter.  The 
total  quantity  in  1846  from  Europe 
amounted  to  249,664  cwt.,  and  from  the 
United  States  to  91,901  cwt.  The  Ameri- 
can cheese,  however,  is  said  to  have  some 
faults  which  need  to  be  corrected  to  ren- 
der it  acceptable  to  the  English  market. 
These  are  stated  by  Mr.  Coleman  to  be, 
first,  the  softness  of  the  rind,  which  ren- 
ders them  liable  to  crack,  and  which  is 
imputed  to  their  richness,  and  the  remedy 
for  which  is  to  let  the  cheese,  when  taken 
from  the  press,  remain  in  brine  so  strong 


90 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[cm 


that  it  mil  take  up  no  more  salt,  for  four 
or  five  hours.  It  must  not,  however,  be 
kept  too  long  in  the  brine,  as  it  may  re- 
ceive injury.  The  second  fault  complain- 
ed of  is  the  acid  and  sharp  taste.  This 
is  imputed  to  some  improper  preparation 
of  the  rennek,  and  possibly  to  something 
wrong  in  the  feed  or  pastures.  Cheese  of 
good  quality  is  manufactured  in  Saxony 
from  potatoes.  These  are  boiled,  peeled 
and  pulpified  with  rasps.  1  lb.  of  sour 
milk  is  added  to  5  lbs.  of  this  pulp,  mixed 
well  and  set  aside  for  four  days.  It  is  then 
kneaded,  the  moisture  drained  off,  and 
thev  are  potted.    They  improve  by  age. 

CHEMITYPE.  A  newly  invented  style 
of  printing,  the  object  of  which  is  to  su- 
persede, to  a  great  extent,  wood-cutting. 
By  this  method,  an  etching  or  engraving 
made  in  metal  in  the  usual  way,  may  be 
converted  into  a  high  relieve  stamp,  to  be 
used  for  printing  on  an  ordinary  press,  as 
is  the  case  with  common  wood  engravings. 
The  following  statement  may  in  general 
illustrate  the  character  of  the  invention: 
On  a  highly  polished  plate  of  pure  zinc 
an  etching  or  engraving  is  made  in  the 
usual  manner,  which,  under  common  cir- 
cumstances, would  be  fitted  for  impres- 
sions on  an  engraver's  press,  having  the 
same  harmony  and  proportion  of  all  the 
respective  etched  or  engraved  lines.  The 
tracery  thus  deepened  is  now  to  be  fused 
or  melted  down  with  a  negative  metal, 
and  the  original  metal  plate  (zinc)  cor- 
roded, or  etched  by  means  of  a  certain 
acid,  thus  making  the  characters  of  the 
former  drawing  appear  in  the  shape  of  a 
high  relieve  stamp.  This  effect  is  only 
produced  in  consequence  of  the  metal 
composition  in  the  lines  of  the  tracery 
not  being  acted  upon  by  the  acid  on  ac- 
count of  the  galvanic  agency  subsisting 
between  the  two  metals,  and  the  acid 
corroding  only  the  zinc. 

As  every  drawing  on  the  metal  plate  is 
completely  exact  on  the  relieve  stamp, 
the  practice  is  absolutely  independent^ 
the  exact  and  accurate  representation  of 
the  original  sketch  is  always  to  be  expect- 
ed. Wood-engraving  cannot,  in  most 
cases,  be  superseded  by  this  novel  me- 
thod; but  in  many  other  instances  the 
new  practice  is  preferable,  chiefly  when 
colored  printing  is  required,  in  the  repre- 
sentation of  maps,  plans,  architectural 
drawings,  &c,  &c.  At  the  same  time, 
the  correction  or  improvement  of  any 
drawing  can  be  much  better  executed 
than  in  wood-engraving. 

CHIMNEY.  (Fr.  cheminee.)  The 
place  in  a  room  where  the  fire  is  burnt, 


and  from  which  the  smoke  is  carried 
away  by  means  of  a  conduit  called  a  flue. 
Chimneys  are  usually  made  by  projection 
from  a  wall,  and  recess  in  the  same  from 
the  floor,  ascending  within  the  limits  of  the 
projection  and  recess.  That  part  of  the 
opening  which  faces  the  room  is  properly 
the  fire-place,  the  stone  or  marble  under 
which  is  called  the  hearth.  That  on  a 
level  with,  and  in  front  of  it,  is  called  the 
slab.  The  vertical  sides  of  the  opening 
are  called  jambs.  The  head  of  the  fore- 
plate  resting  on  the  jambs  is  called  the 
mantel;  and  the  cavity  or  hollow  from 
the  fire-place  to  the  top  of  the  room  is 
called  the  funnel.  The  part  of  the  funnel 
which  contracts  as  it  ascends  is  termed 
the  gathering,  or  by  some  the  gathering  of 
the  wings.  The  tube  or  cavity  of  a  paral- 
lelogrammatic  form  on  the  plan,  from 
where  the  gathering  ceases  up  to  the  top 
of  the  chimney,  is  called  the  flue.  The 
part  between  the  gathering  and  the  flue 
is  called  the  throat.  The  part  of  the  wall 
facing  the  room,  and  forming  one  side  of 
the  funnel  parallel  thereto,  on  the  part  of 
the  wall  forming  the  sides  of  the  funnels, 
where  there  are  more  than  one,  is  the 
breast.  In  external  walls,  that  side  of  the 
funnel  opposite  the  breast  is  called  the 
back.  When  there  is  more  than  one 
chimney  in  the  same  wall,  the  solid  parts 
that  divide  them  are  called  withs.  And 
when  several  chimneys  are  collected  into 
one  mass,  it  is  called  a  stack  of  chimneys. 
The  part  which  rises  above  the  roof  for 
discharging  the  smoke  into  the  air,  is 
called  a  chimney  shaft,  whose  horizontal 
upper  surface  is  termed  the  chimney  top. 
The  covings  were  formerly  placed  at 
right  angles  to  the  face  of  the  wall,  and 
the  chimney  was  finished  in  that  manner; 
but  Count  Rumford  showed  that  more 
heat  is  obtained  from  the  fire  by  reflexion 
when  the  covings  are  placed  in  an  oblique 
position.  He  likewise  directed  that  the 
fire  itself  should  be  kept  as  near  to  the 
hearth  as  possible,  and  that  the  throat  of 
I  the  chimney  should  be  constructed  much 
|  narrower  than  had  been  practised,  with 
j  a  view  to  prevent  the  escape  of  so  much 
j  heated  air  as  happened  with  wide  throats. 
'  If  the  throat  be  too  near  the  fire,  the 
j  draught  will  be  too  strong,  and  the  fuel 
will  be  wasted ;  and  if  it  be  too  high  up, 
;  the  draught  will  be  too  languid,  and  there 
I  will  be  a  clanger  of  the  smoke  being  occa- 
sionally beat  back  into  the  room.  Beforo 
Count  Rumford  directed  his  attention  to 
this  subject,  smoky  chimneys  were  very 
'  common  ;  but  by  studying  his  principles, 
:  these  at  present  seldom  occur. 


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CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


91 


Lieut.  Mason,  in  a  letter  to  the  London 
Builder  on  the  subject  of  smoky  chim- 
neys, writes  :  "  I  have  built  many  chim- 
neys in  all  possible  situations,  and  have 
found  one  simple  plan  everywhere  suc- 
ceeded, the  secret  being  only  to  construct 
the  throat  of  the  chimney,  or  that  part 
of  it  just  above  the  fire-place,  so  small 
that  a  man  or  a  boy  can  barely  pass 
through  it.  Immediately  above  this 
the  chimney  should  be  enlarged  to  double 
its  width,  like  a  purse,  to  the  extent  of 
about  two  feet  in  height,  and  then  dimin- 
ished again  to  its  usual  proportions.  No 
chimney  that  I  ever  constructed  thus, 
smoked." 

CHINA  INK.  The  finest  kind  of  this 
useful  pigment  is  seldom  met  with  in  our 
market.  According  to  a  description  in  a 
Japanese  book,  it  is  made  from  the  con- 
densed smoke  or  soot  of  burned  camphor : 
and  hence,  when  of  the  best  quality,  it 
has  this  odor.  Most  of  the  China  ink  is 
made  from  oil-lampblack  occasionally  dis- 
guised, as  to  smell,  with  musk,  or  with  a 
little  camphor  black.  The  binding  sub- 
stance is  gelatine,  commonly  made  from 
parchment  or  ass's  skin;  but  isinglass 
answers  equally  well.  A  good  imitation 
may  be  made  by  dissolving  isinglass  in 
warm  water,  with  the  addition  of  a  very 
little  alkali  (soda),  to  destroy  its  gelatin- 
izing power,  and  incorporating  with  that 
solution,  by  levigation  on  a  porphyry 
slab,  as  much  of  the  finest  lampblack  as 
to  produce  a  mass  of  the  pi-oper  consist- 
ence. The  minute  quantity  of  alkali 
serves  also  to  saponify  the  oil  which  usu- 
ally adheres  to  lampblack,  and  thereby  to 
make  a  pigment  readily  miscible  with 
water. 

CH I NTZ.  A  peculiar  pattern  on  print- 
ed calicos,  in  which  flowers  and  other  de- 
vices are  printed  in  five  or  six  different 
colors,  upon  white  and  colored  grounds. 
A  good  chintz  pattern  in  fast  colors  is  one 
of  the  most  surprizing  and  difficult  efforts 
of  the  art. 

CHLORAL.  A  liquid,  obtained  by 
the  action  of  chlorine  eras  upon  alcohol. 

CHLORATE  OF  POTASH.  A  salt 
composed  of  chloric  acid  and  potass.  It 
is  formed  by  passing  chlorine  gas  through 
a  solution  of  caustic  potass  till  no  more 
gas  is  absorbed,  evaporating  the  liquor 
and  crystallizing.  By  the  action  of  the 
gas  two  salts  are  formed :  a  chloride  of 
potassium  and  a  chlorate  of  potass, — the 
former  remains  in  solution,  the  latter 
crystallizes  readily,  and  it  may  be  separ- 
ated thus  from  the  chloride.  Washing 
and  1  ecrystallization  are  necessary  to  ob- 


tain a  pure  salt.  Mr.  Calvert's  improved 
process  consists  in  forming  a  mixture  of 
5s-  ounces  of  burnt  lime  for  1  equivalent 
of  caustic  potash,  and  passing  a  current 
of  chlorine  through  the  not  mixture.  In 
this  wa}'  chloride  of  calcium  and  chlorate 
of  potash  are  formed.  The  loss  of  potash 
is  thus  avoided.  Chlorate  of  potash  cry- 
stallizes in  flat,  pearly-looking  plates,  and 
has  an  unpleasant  cool  taste ;  it  does  not 
bleach.  It  dissolves  in  six  parts  of  cold 
water,  and  when  heated  to  redness,  gives 
out  39  per  cent,  of  oxygen ;  if  rubbed 
hardly  in  a  mortar,  it  crackles  and  gives 
off  sparks.  When  rubbed  with  sulphur 
and  phosphorus,  it  detonates  danger- 
ously. A  mixture  of  this  salt  with  sugar 
and  sulphuret  of  antimony,  is  used  for 
tipping  lucifer  matches,  as  it  explodes 
when  rubbed  on  emery  or  sand-paper.  It 
formed  the  detonating  powder  which  was 
dropped  in  percussion  caps ;  but  owing 
to  trie  rusting  property  of  the  gases  pro- 
duced by  explosion,  fulminate  of  mercury 
is  now  preferred. 

Owing  to  its  property  of  giving  off  oxy- 
gen readily  when  decomposed,  it  has 
been  used  to  some  extent  in  bleaching 
fats  and  oils.  It  contains  76  parts  of 
chloric  acid,  and  48  of  potassa,  in  124 
parts  of  the  chlorate. 

CHLORATES.  Combination  of  chloric 
acid  with  salifiable  bases. 

CHLORIDE  OF  LIME— BLEACH- 
ING POWDER.  Its  composition  is  tot 
yet  fully  determined.  The  chief  agent 
in  bleaching  appears  to  be  the  hypochlor- 
ite of  lime,  one  of  the  constituents.  It 
constitutes  a  large  branch  of  chemical 
manufacture,  which  is  carried  on  in  con- 
nection with  that  of  carbonate  of  soda. 

When  hydrate  of  lime,  very  slightly 
moist,  is  exposed  to  chlorine  gas,  the  lat- 
ter is  eagerly  absorbed,  and  a  compound 
produced  which  has  attracted  a  great  deal 
of  attention :  this  is  the  bleaching  pow- 
der of  commerce,  now  manufactured  on 
an  immense  scale,  for  bleaching  linen 
and  cotton  goods.  It  is  requisite,  in  pre- 
paring this  substance,  to  avoid,  with  the 
greatest  care,  all  elevation  of  temperature, 
which  may  be  easily  done  by  slowly  sup- 

? lying  the  chlorine  in  the  first  instance, 
'he  product,  when  freshly  and  well  pre- 
pared, is  a  soft,  white  powder,  which  at- 
tracts moisture  from  the  air,  and  exhales 
an  odor  sensibly  different  from  that  of 
chlorine.  It  is  soluble  in  about  10  parts 
of  water,  merely  the  unaltered  hydrate 
being  left  behind  ;  the  solution  is  highly 
alkaline,  and  bleaches  feebly.  When  hy- 
drate of  lime  is  suspended  in  cold  water, 


92 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[CHL 


and  chlorine  gas  transmitted  through  the 
mixture,  the  lime  is  gradually  dissolved, 
and  the  same  peculiar  bleaching  com- 
pound produced ;  the  alkalies  also,  either 
caustic  or  carbonated,  may,  by  similar 
means,  be  made  to  absorb  a  large  quan- 
tity of  chlorine,  and  give  rise  to  corres- 
ponding compounds ;  such  are  the  "  dis- 
infecting solutions"  of  M.  Labarraque. 

The  most  consistent  view  of  the  con- 
stitution of  these  curious  compounds  is 
that  which  supposes  them  to  contain 
salts  of  hydrochlorous  acid,  a  substance 
as  remarkable  for  bleaching  powers  as 

Chlorine 

Lime     j  Oxygen 
I  Calcium 
Chlorine 
Lime 


chlorine  itself;  and  this  opinion  seems 
borne  out  by  a  careful  comparison  of  tha 
properties  of  the  bleaching  salts  with 
those  of  the  true  hypochlorites.  Hypo- 
chlorous  acid  can  be  actually  obtained 
from  good  bleaching  powder,  by  distill- 
ing it  with  dilute  sulphuric  or  nitric  acid, 
in  quantity  insufficient  to  decompose  the 
whole ;  when  the  acid  is  used  in  excess, 
chlorine  is  disengaged. 
_  If  this  view  be  correct,  chloride  of  cal- 
cium must  be  formed  simultaneously  with 
the  hypochlorite,  as  in  the  following  dia- 
gram : 

Chloride  of  calcium. 


Hyperchlorite  of  lime. 


When  the  temperature  of  the  hydrate 
of  lime  has  risen  during  the  absorption 
of  the  chlorine,  or  when  the  compound 
has  been  subsequently  exposed  to  heat, 
its  bleaching  properties  are  impaired,  or 
altogether  destroyed;  it  then  contains 
chlorate  of  lime  and  chloride  of  calcium ; 
oxygen,  in  variable  quantity,  is  usually 
set  free.  The  same  change  seems  to  en- 
sue by  long  keeping,  even  at  the  common 
temperature  of  the  air.  In  an  open  ves- 
sel it  is  speedily  destroyed  by  the  carbonic 
acid  of  the  atmosphere.  Commercial 
bleaching  powder  thus  constantly  varies 
in  value  with  its  age,  and  with  the  care 
originally  bestowed  upon  its  preparation ; 
the  best  may  contain  about  30  per  cent, 
of  available  chlorine,  easily  liberated  by 
lu.  acid,  which  is,  however,  far  short  of 
the  theoretical  quantity. 

The  general  method  in  which  this  sub- 
stance is  employed  for  bleaching  is  the 
following :  The  goods  are  first  immersed 
in  a  dilute  solution  of  chloride  of  lime, 
and  then  transferred  to  a  vat  containing 
dilute  sulphuric  acid  ;  the  chlorine  or  hy- 
pochlorous  acid  thus  disengaged  in  con- 
tact with  the  cloth,  causes  the  "destruction 
of  the  coloring  matter.  This  process  is 
often  repeated,  it  being  unsafe  to  use 
strong  solutions.  White  patterns  are,  on 
this  principle,  imprinted  on  colored  cloth, 
the  figures  being  stamped  with  tartaric 
acid  thickened  with  gum-water,  and  then 
the  stuff"  immersed  in  the  chloride  bath, 
when  the  parts  to  which  no  acid  has 
been  applied  remain  unaltered,  while  the 
printed  portions  are  bleached. 

For  purifying  an  offensive  or  infections  | 
atmosphere^  as  an,  aid  to  proper  ventilation,  I 


the  bleaching  powder  is  very  convenient. 
The  solution  is  exposed  in  shallow  ves- 
sels, or  cloths  steeped  in  it  are  suspended 
in  the  apartment,  when  the  carbonic 
acid  of  the  air  slowly  decomposes  the 
chloride.  An  addition  of  a  strong  acid 
causes  rapid  disengagement  of  chlo- 
rine. 

The  value  of  any  sample  of  bleaching 
powder  may  be  easily  determined  by  the 
following  method,  in  which  the  loosely- 
combined  chlorine  is  estimated  by  its  ef- 
fect in  peroxidizing  a  proto-salt  of  iron, 
of  which  two  equivalents  require  one  oi 
chlorine  ;  the  latter  acts  by  decomposing 
water  and  liberating  a  corresponding 
quantity  of  oxygen — 78  grains  of  green 
sulphate  of  iron  are  dissolved  in  about 
two  ounces  of  water,  and  acidulated  by  a 
few  drops  of  sulphuric  or  hydrochloric 
acid ;  this  quantity  will  require  for  per- 
oxidation exactly  "l0  grains  of  chlorine. 
Fifty  grains  of  the  chloride  of  lime  to  be 
examined  are  next  rubbed  up  with  a  little 
tepid  water,  and  the  whole  transferred  to 
the  alkalimcter  before  described,  which 
is  then  filled  up  to  0  with  water,  after 
which  the  contents  are  well  mixed  by 
agitation.  The  liquid  is  next  gradually 
poured  into  the  solution  of  iron,  with 
constant  stirring  until  the  latter  has  be- 
come peroxidized,  which  may  be  known 
by  a  drop  ceasiug  to  give  a  deep  blue 
precipitate  with  red  ferrocyanide  of  pot- 
assium. The  number  of  grain-measures 
of  the  chloride  solution  employed  may 
then  be  read  off,  and  since  these  must 
contain  10  grains  of  serviceable  chlorine, 
the  quantity  of  the  latter  in  the  50  grains 
may  be  easily  reckoned.    Thus,  suppose 


chl] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


93 


72  such  measures  have  been  taken,  then 

Measures.    Gms.  chlorine.    Measures.    Gms.  chlorine. 

72       :        10       :  :       100      :       13-89 
The  bleaching  powder  contains,  therefore, 
27*78  per  cent. 

A  partv  of  Germans  have  erected  in 
Steubenville,  Ohio,  an  establishment  for 
the  manufacture  of  soda  ash  and  chloride 
of  lime.  It  is  the  only  one  of  the  kind 
in  the  United  States  ;  it  is  estimated  that 
during  the  first  year  it  will  produce  be- 
tween"$40,000  and  $50,000  worth  of  soda 
ash,  and  nearly  $20,000  in  value  of  chlor- 
ide of  lime.  It  is  supposed  that  the 
amount  of  manufacture  will  be  doubled 
the  second  year. 

CHLORIDES.  Combinations  of  chlo- 
rine, corresponding  with  the  oxides.  Com- 
mon salt  is  a  chloride  of  sodium  ;  that  is, 
a  binary  compound  of 'chlorine  and  sodi- 
um. Where  there  are  two  chlorides  of 
the  same  base,  the  relative  proportions  of 
chlorine  in  them  are  almost  invariably  as 
1  to  2  :  hence  the  terms  protochhride  and 
bichloride.  Calomel  and  corrosive  subli- 
mate arc  the  protochloride  and  bichloride 
of  mercury.  The  latter  is  frequently 
termed  perchloride.  In  calomel,  200  of 
mercury  are  combined  with  36  of  chlo- 
rine, and  in  corrosive  sublimate  with 
twice  36,  or  72. 

CHLORINE.  This  gas  was  discovered 
in  1774  by  Scheele,  who  called  it  dephlo- 
gisticated  muinatic  acid  •  the  French  no- 
mcnclaturists  afterwards  termed  it  oxygen- 
ated muriatic  acid,  conceiving  it  to  be  a 
compound  of  oxygon  and  muriatic  acid. 
This  erroneous  viow  of  its  nature  waa 
corrected  in  1809  by  Sir  II.  Davy,  who 
gave  it  the  present  ntune,  indicative  i  f 
its  color.  Chlorine  is  s.  simple  substanc  ;, 
existing  at  common  temperatures  ar.d 
pressures  in  the  gaseous  state  ;  but  wh^n 
subjected  to  a  pressure  of  about  fom  at- 
mospheres, it  become:!  condensed  iri)  a 
yellow  transparent  liq aid,  which  io  t.  non- 
conductor of  electricity.  100  cibical 
inches  of  chlorine,  at  mean  temr/jiature 
and  pressure,  weign  between  7c  and  77 
grains  :  water  absorbs  twice  its  volume, 
and  acquires  a  yeJJow  color,  ur.d  the  pe- 
culiar suffocating  odor  of  tho  gas.  When 
humid  chlorine  in  exposed  to  a  tempera- 
ture of  32°,  it  as* ames  a  crystalline  form  ; 
this  hydrate  of  chlorine  consists  of  1  equi- 
valent of  chlorine  =  37  -f  10  of  water  —  9 
•+•  10  or  90.  Chlorine  is  not  only  unre- 
spirable,  but  very  injurious  when  breath- 
ed, even  if  largely  diluted  ;  a  taper  burns 
in  it  with  a  red  smoky  flame,  and  is  soon 
extinguished.    Some  of  the  metals,  when 


finely  divided,  spontaneously  take  fire  in 
chlorine,  such  as  brass  leaf,  or  powdered 
antimony.  A  remarkable  property  ot 
chlorine  is  its  power  of  destroying  almost 
all  vegetable  and  animal  colors :  hence 
the  important  application  of  this  gas  and 
of  some  of  its  combinations  to  the  art  oj 
bleaching.  It  also  destroys  the  putrid 
odor  of  decomposing  vegetable  and  ani- 
mal substances,  and  infectious  effluvia  of 
all  kinds  :  whence  its  use  in  fumigation, 
and  in  preventing  the  spread  of  infecti- 
ous and  contagious  matter,  and  purifying 
noxious  atmospheres. 

The  great  natural  source  of  chlorine  is 
common  salt,  which  contains  it  in  the  pro- 
portion of  about  60  per  cent.  It  is  pro- 
cured by  decomposing  common  salt  by 
the  joint  agency  of  sulphuric  acid  and 
peroxide  of  manganese.  The  best  pro- 
portions are  3  parts  of  salt  and  1  of  oxide 
of  manganese ;  these  are  well  mixed,  and 
put  into  a  retort  with  2  parts  of  sulphuric 
acid  previously  diluted  with  2  of  water. 
Chlorine  is  evolved,  and  its  extrication  is 
quickened  by  the  application  of  a  gentle 
heat.  Chlorine  may  also  be  obtained 
from  a  mixture  of  muriatic  acid  with  half 
its  weight  of  black  oxide  of  manganese. 
The  gas  may  be  collected  over  water,  and 
should  be  preserved  in  bottles  with  glass 
stoppers;  if  left  in  the  contact  of  water, 
it  is  soon  absorbed.  (See  Muriatic  Acid.) 

CHLORIODINE,  OR  CHLORIODIC 
ACID.  A  compound  of  chlorine  and 
iodine. 

CHLORITE.  An  earthy  mineral  of  a 
green  color,  often  found  in  the  cavities 
and  veins  of  slate  rocks. 

CHLOROCARBONIC  ACID.  A  com- 
pound formed  by  exposing  a  mixture  of 
chlorine  and  carbonic  oxide  to  the  action 
ofliffht, 

CHLOROCYANIC  ACID.  A  com- 
pound of  chlorine  and  cyanogen. 

CHLOROFORM.  A  most  valuable 
agent  to  the  physician  in  producing  tem- 
porary insensibility  to  pain :  and  a  still 
more  useful  aid  in  the  arts,  where  it  has 
taken  its  place  as  a  solvent  for  many 
resins,  &c.  It  is  obtained  by  distilling 
alcohol,  woodspirit,  or  acetone  with  a  so- 
lution of  chloride  of  lime.  One  part  of 
hydrate  of  lime  is  suspended  m  four 
parts  of  cold  water,  and  chlorine  passed 
through  the  mixture  until  nearly  the 
whole  lime  is  dissolved.  A  little  more 
hydrate  is  then  added  to  restore  the  al- 
kaline reaction,  the  clear  liquid  mixed 
with  one  part  of  alcohol  or  woodspirit, 
and,  after  an  interval  of  24  hours,  cau- 
tiously distilled  in  a  very  spacious  vessel. 


94 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[CHO 


A  watery  liquid  containing  a  little  spirit, 
and  a  heavy  oil  collect  in  the  receiver ; 
the  latter,  in  which  is  the  chloroform,  is 
agitated  with  water,  digested  with  chlo- 
ride of  calcium,  and  rectified  in  a  water- 
bath.  It  is  a  thin,  colorless  liquid  of 
agreeable  ethereal  odor,  much  resembling 
that  of  Dutch- liquid,  and  sweetish  taste. 
Its  density  is  1*48,  and  it  boils  at  141° ; 
the  density  of  its  vapor  is  4*1 16.  Chloro- 
form is  with  difficulty  kindled,  and  burns 
with  a  greenish  flame.  It  is  nearly  in- 
soluble in  water,  and  is  not  affected,  by 
concentrated  sulphuric  acid.  Alcoholic 
solution  of  potash  quickly  decomposes  it 
with  production  of  chloride  of  potassium 
and  formiate  of  potash. 

Chloroform  contains  C*  H  CI3  ;  it  is 
changed  to  formic  acid  by  the  substitu- 
tion of  three  eq.  of  oxygen  for  the  three 
eq.  of  chlorine  removed  by  the  alkaline 
metal. 

It  is  difficult  to  obtain  pure  chloro- 
form. Gregory  directs  it  to  be  agitated 
with  oil  of  vitriol  and  filtered  subse- 
quently through  oxide  of  manganese  :  it 
will  then  be  free  from  impurity  and  keep 
better. 

Chloroform  has  already  been  applied 
to  many  uses ;  it  is  a  valuable  test  for 
iodine  and  other  bodies  in  the  hand  of 
the  chemist :  gutta  percha  dissolved  in 
it,  constitutes  the  collodion  or  artificial 
skin  used  by  the  surgeon  in  dressing 
abraded  surfaces.  It  dissolves  bro- 
mine and  the  essential  oils,  gun  cotton, 
caoutchouc,  copal  and  gum  lac ;  and  if 
produced  sufficiently  cheap,  would  be  a 
valuable  substance  in  the  manufacture  of 
varnishes.  The  credit  of  first  using  sub- 
stances for  producing  insensibility,  of 
which  ether  and  chloroform  are  the 
chief,  belong  to  this  country — having 
been  first  applied  by  Dr.  Jackson  of 
Boston,  and  Mr.  Morton. 

CHLOROMETER.  An  instrument  for 
the  purpose  of  testing  the  decoloring  or 
bleaching  powers  of  chloride  of  lime,  by 
which  the  relative  values  of  different 
samples  of  that  important  bleaching  and 
disinfecting  compound  may  be  ascer- 
tained. 

CHLOROPHAlTE.  A  mineral,  which, 
when  recently  broken,  is  green,  but  af- 
terwards becomes  black. 

CHLOROPHANE.  A  species  of  fluor 
spar,  which,  when  heated,  shines  with  a 
beautiful  pale-green  light. 

CHLOROPHYLL.  The  green  color- 
ing matter  of  the  leaves  of  plants. 

CHOCOLATE  is  an  alimentary  prepa- 
ration of  very  ancient  use  in  Mexico, 


from  which  country  it  was  introduced 
into  Europe  by  the  Spaniards  in  the 
year  1520,  and  by  them  long  kept  a  secret 
from  the  rest  of  the  world.  Linnaeus 
was  so  fond  of  it,  that  he  gave  the  speci- 
fic name,  iheobroma  (food  of  the  gods),  to 
the  cacoa-tree  which  produced  it.  The 
cacao-beans  lie  in  a  fruit  somewhat  like 
a  cucumber,  about  5  inches  long  and  3i 
thick,  which  contains  from  20  to  30 
beans,  arranged  in  5  regular  rows  with 
partitions  between,  and  which  are  sur- 
rounded with  a  rose-colored  spongy  sub- 
stance, like  that  of  water-melons.  There 
are  fruits,  however,  so  large  as  to  contain 
from  40  to  50  beans.  Those  grown  in 
the  West  India  islands,  Berbice  and  De- 
marara,  are  much  smaller,  and  have  only 
from  6  to  15;  their  development  being 
less  perfect  than  in  South  America.  After 
the  maturation  of  the  fruit,  when  their 
green  color  has  changed  to  a  dark-yel- 
low, they  are  plucked,  opened,  their 
beans  cleared  of  the  marrowy  substance, 
and  spread  out  to  dry  in  the  air.  Like 
almonds,  they  are  covered  with  a  thin 
skin  or  husk.  In  the  West  Indies,  they 
are  immediately  packed  up  for  the  market 
when  they  are  dried ;  but  in  the  Caraccas, 
they  are  subjected  to  a  species  of  slight 
fermentation,  by  putting  them  into  tubs 
or  chests,  covering  them  with  boards  or 
stones,  and  turning  them  over  every 
morning  to  equalize  the  operation. 

Dr.  lire  in  his  Dictionary  of  Arts,  from 
which  this  article  is  condensed,  gives  an 
analysis  of  Guayaquil  coco,  made  by  him- 
self,'as  follows : 
Concrete  fat  or  butter  of  coco,  dissolv- 
ed out  by  ether 87 

Brown  extractive,  extracted  by  hot 

water,  after  the  operation  of  ether. .      10 
Ligneous  matter,  with  some  albumine      30 

Shells 14 

Water 6 

Loss 3 

100 

Dr.  U.  thinks :  "  the  solid  fat  of  the  coec 

I  should  be  most  intimately  combined  by 

i  milling  with   the   extractive,  albumine, 

j  and  ligneous  matter,  in  order  to  render 

!  it  capable  of  forming  an  emulsion  with 

water ;  and,  indeed,  on  account  of  the 

large  proportion  of  concrete  fat  in  the 

beans,  some  additional  substance  should 

be  introduce  to  facilitate  this  emulsive 

union  of  the  fat  and  water.    Sugar,  gum, 

and  starch  or  flour,  are  well  adapted  for 

this  purpose." 

The  fatty  matter  is  of  the  consistence 
of  tallow,  white,  of  a  mild  agreeable  taste, 
called  butter  of  cacao,  and  not  apt  to 


chr] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


95 


turn  rancid  by  keeping.  It  melts  only 
at  122°  Fahr.,  ana  should,  therefore, 
make  tolerable  candles.  It  is  soluble  in 
boiling  alcohol,  but  precipitates  in  the 
cold.  It  is  obtained  by  exposing  the 
beans  to  strong  pressure  in  canvass  bags, 
after  they  have  oeen  steamed  or  soaked 
in  boiling  water  for  some  time.  From  5 
to  6  ounces  of  butter  may  be  thus  ob- 
tained from  a  pound  of  cacao.  It  has  a 
reddish  tinge  when  first  expressed,  but 
it  becomes  white  by  boiling  with  water. 

The  beans,  being  freed  from  all  spoiled 
and  mouldy  portions,  are  gently  roasted 
over  a  fire  in  an  iron  cylinder,  with  holes 
in  its  ends  for  allowing  the  vapors  to 
escape  ;  the  apparatus  being  similar  to  a 
coffee -roaster.  When  the  aroma  begins 
to  be  well  developed,  the  roasting  is 
known  to  be  finished;  and  the  beans 
must  be  turned  out,  cooled,  and  freed  by 
fanning  and  sifting  from  their  husks. 
The  kernels  are  then  to  be  converted 
into  a  paste,  either  by  trituration  in  a 
mortar  heated  to  130°  F.,  or  by  the  aid 
of  an  ingenious  and  powerful  machine. 
The  chocolate  paste  has  usually  in  France 
a  little  vanilla  incorporated  with  it,  and 
a  considerable  quantity  of  sugar,  which 
varies  from  one-third  of  its  weight  to 
equal  parts.  For  a  pound  and  a  half  of 
cacao,  one  pod  of  vanilla  is  sufficient. 
Chocolate  paste  improves  in  its  flavor  by 
keeping,  and  should  therefore  be  made 
in  large  quantities  at  a  time.  But  the 
roasted  beans  soon  lose  their  aroma,  if 
exposed  to  the  air. 

CHEOMATYPE,  is  a  new  process  of 
photography.     It    consists    in  washing 

f^ood  letter-paper  with  the  following  so- 
ution : — Bichromate  of  potash,  10  grains  • 
sulphate  of  copper,  20  grains ;  distilled 
water,  1  ounce.  Papers  prepared  with 
this  are  of  a  pale-yellow  color,  and  may 
be  kept  for  any  length  of  time  without 
injury,  and  are  always  ready  for  use. 
For  copying  botanical  specimens,  or  en- 
gravings, nothing  can  be  more  beautiful. 
After  the  paper  has  been  exposed  to  the 
influence  of  sunshine,  with  the  object  to 
be  copied  superposed,  it  is  washed  over 
in  the  dark  with  a  solution  of  nitrate  of 
silver  of  moderate  strength  ;  as  soon  as 
this  is  done  a  very  vivid  positive  picture 
makes  its  appearance,  which  then  only 
requires  washing  in  pure  water. 

CHEOM1UM,  {Chrome.)    A  metal  dis- 
covered by  Vauquelin  in  1797.    It  exists 
chiefly  in  two  native  compounds ;  the 
one  formerly  called  red  lead  of  Siberia,  ; 
which  is  a  chromate  of  lead ;  the  other,  a  '' 
compound  of  the  oxides  of  chromium  ! 


and  iron.  Chromium  is  a  whitish,  brit- 
tle, and  very  infusible  metal ;  sp.  gr.  5-5. 
When  heated  with  nitre,  it  is  converted 
into  chromic  acid.  Its  equivalent  num- 
ber is  28.  It  forms  two  compounds  with 
oxygen, — a  green  oxide,  and  a  red  per- 
oxide ;  the  latter  being  sour,  and  com- 
bining with  salefiable  bases,  is  called 
chromic  acid.  The  oxide  consists  of  28 
chromium  +  12  oxygen  ;  and  chromic 
acid  of  28  chromium  -f  24  oxygen.  Chro- 
mic acid  is  of  a  red  color,  and  forms  a 
variety  of  colored  compounds,  some  of 
which  are  much  used  in  the  arts  ;  such 
as  the  chromate  and  bichromate  of  potash, 
largely  manufactured  for  the  use  of  cali- 
co-printers, and  the  chromates  of  lead, 
employed  as  yellow  and  red  dyes  and 
paints.  The  oxide  of  chrome  is  green, 
and  furnishes  a  valuable  color  for  porce- 
lain and  in  enamel.  Chromic  acid  gives 
color  to  the  ruby,  and  the  green  of  the 
emerald  is  due  to  oxide  of  chrome. 

Chrome  iron  ore  is  found  in  abund- 
ance distributed  over  the  United  States. 
In  Maryland,  at  the  Bare  Hills  near  Bal- 
timore ;  and  in  Delaware  county,  Pa.,  it 
is  found  very  plentifully.  In  that  locality, 
one  firm  has  upwards  of  100  hands  em- 
ployed, and  are  daily  shipping  the  mi- 
neral to  Baltimore.  The  proprietors  of 
farms  upon  which  it  is  found,  receive  $3 
per  ton  for  washed  chrome — and  in  the 
rock  state  it  is  sometimes  worth  $5  per 
ton.  Mr.  WTood's  chrome  iron  ore  mine, 
on  the  Eiver  Ortorara,  separating  Chester 
and  Lancaster  counties,  Pa.,  is  probably 
the  most  extensive  chrome  mine  in  the 
world,  being  170  feet  deep — 200  feet  long 
and  30  feet  broad :  the  ore  yields  93  per 
cent,  of  oxide  of  chrome.  The  mineral 
is  also  found  in  great  abundance  at  vari- 
ous points  east  of  the  Mine  Eidge,  in 
Lancaster,  Chester,  and  Delaware  coun- 
ties, Pa.,  and  is  all,  or  nearly  all,  shipped 
to  Baltimore,  whence  it  is  exported  large- 
ly to  Europe.  This  ore  forms  the  basis  of 
many  of  the  colored  preparations  of 
chrome,  for  which  see  Dyeing. 

The  chief  application  of  this  ore  is  to 
the  production  of  chromate  of  potash, 
from  which  salt  the  various  other  prepa- 
rations of  this  metal  used  in  the  arts  are 
obtained.  The  ore,  freed,  as  well  as  pos- 
sible, from  its  gangue,  is  reduced  to  a 
fine  powder,  by  being  ground  in  a  mill 
under  ponderous  edge-wheels,  and  sifted. 
It  is  then  mixed  with  one-third  or  one- 
half  its  weight  of  coarsely  bruised  nitre, 
and  exposed  to  a  powerful  heat,  for  seve- 
ral hours,  on  a  reverberatory  hearth, 
where  it  is  stirred  about  occasionally.  In 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


the  large  manufactories  of  this  country, 
the  ignition  of  the  above  mixture  in  pots 
is  laid  aside,  as  too  operose  and  expen- 
sive. The  calcined  matter  is  raked  out, 
and  lixiviated  with  water.     The  bright- 

J'ellow  solution  is  then  evaporated  brisk- 
y,  and  the  chromate  of  potash  falls  down 
in  the  form  of  a  granular  salt,  which  is 
lifted  out  from  time  to  time  from  the 
bottom  with  a  large  ladle,  perforated  with 
small  holes,  and  thrown  into  a  draining- 
box.  This  saline  powder  may  be  formed 
into  regular  crystals  of  neutral  chromate 
of  potash,  by  solution  in  water  and  slow 
evaporation ;  or  it  may  be  converted  into 
a  more  beautiful  crystalline  body,  the 
bichromate  of  potash,  by  treating  its  con- 
centrated solution  with  nitric,  muriatic, 
sulphuric,  or  acetic  acid,  or,  indeed,  any 
acid  exercising  a  stronger  affinity  for  the 
second  atom  of  the  potash  than  the  chro- 
mic acid  does. 

Bichromate  of  potash,  by  evaporation 
of  the  above  solution,  and  slow  cooling, 
may  be  obtained  in  the  form  of  square 
tables,  with  bevelled  edges,  or  flat  four- 
sided  prisms.  They  are  permanent  in 
the  air,  have  a  metallic  and  bitter  taste, 
and  dissolve  in  about  one-tenth  of  their 
weight  of  water,  at  60°  F. ;  but  in  one- 
half  of  their  weight  of  boiling  water. 
Thev  consist  of  chromic  acid  13,  potash 
6 ;  or,  in  100  parts,  68-4  +  31-6.  This  salt 
is  much  employed  in  calico-printing  and 
in  dyeing  ;  which  see. 

Chromate  of  lead,  the  chrome-yellow 
of  the  painter,  is  a  rich  pigment  of  vari- 
ous shades,  from  deep  orange  to  the 
palest  canary-yellow.  It  is  made  by  add- 
ing a  limpid  solution  of  the  neutral  chro- 
mate (the  above  granular  salt)  to  a  solu- 
tion, equally  limpid,  of  acetate  or  nitrate 
of  lead.  A  precipitate  falls,  which  must 
be  well  washed,  and  carefully  dried  out 
of  the  reach  of  any  sulphureted  vapors. 
A  lighter  shade  of  yellow  is  obtained  by 
mixing  some  solution  of  alum,  or  sul- 
phuric acid,  with  the  chromate,  before 
pouring  it  into  the  solution  of  lead  ;  and 
an  orange  tint  is  to  be  procured  by  the 
additiorTof  subacetate  of  lead,  in  any  de- 
sired proportion. 

Lately  great  use  has  been  made  of  the 
green  oxyde  to  dyeing  and  painting  on  por- 
celain. This  oxyde  may  be  prepared  by 
decomposing,  with  heat,  the  chromate  of 
mercury,  a  salt  made  by  adding  to  ni- 
trate of  protoxyde  of  mercury,  chromate 
of  potash,  in  equivalent  proportions. 
This  chromate  has  a  flne  cinnabar  red, 
when  pure ;  and,  at  a  dull  red  heat,  parts 
with  a  portion  of  its  oxygen  and  its  mer- 


curial oxyde.  From  M.  Dulong's  ex- 
periments it  would  appear,  that  the 
Surest  chromate  of  mercury  is  not  the 
est  adapted  for  preparing  the  oxyde  of 
chrome  to  be  used  in  porcelain  painting. 
he  thinks  it  ought  to  contain  a  little 
oxyde  of  manganese  and  chromate  of 
potash,  to  afford  a  green  color  of  a  fine 
tint,  especially  for  pieces  that  are  to  re- 
ceive a  powerful  heat.  Pure  oxyde  of 
chrome  preserves  its  color  well  enough 
in  a  muffle  furnace ;  but,  under  a  stronger 
fire,  it  takes  a  dead-leaf  color. 

An  improved  method  of  making  this 
valuable  color  for  enamelling,  is  to  mix 
intimately  45  parts  of  gunpowder  with 
240  parts  of  perfectly  dry  chromate  of 
potash,  and  35  parts  of  hydrochlorate  of 
ammonia  (sal  ammoniac),  reduce  to  pow- 
der, and  pass  through  a  fine  sieve ;  fill  a 
conical  glass  or  other  mould  with  this 
powder,  gently  pressed,  and  invert  so  as 
to  leave  the  powder  on  a  porcelain  slab 
of  any  kind.  When  set  on  fire  at  its 
apex  with  a  lighted  match,  it  will  burn 
down  to  the  bottom  with  brilliant  corus- 
cations. The  black  residum,  being  elu- 
triated with  warm  water,  affords  a  fine 
bright  green  oxide  of  chromium. 

CHROMIC  ACID.  As  this  substance 
is  now  much  used  by  calico  printers  and 
bleachers,  the  following  mode  of  obtaining 
it  is  subjoined.  To  100  parts  of  yellow 
chromate' cf  potash,  add  136  of  nitrate  of 
barytes,  each  in  solution.  A  precipitate  of 
the  yellow  chromate  of  barytes  falls,  which 
being  washed  and  dried  would  amount 
to  1 30  parts.  But  while  still  moist  it  is  to 
be  dissolved  in  water  by  the  intervention 
of  a  little  nitric  acid,  and  then  decom- 
posed by  the  addition  of  the  requisite 
quantity  of  sulphuric  acid,  whereby  the 
barytes  is  separated,  and  the  chromic 
acid  remains  associated  with  the  nitric 
acid,  from  which  it  can  be  freed  by  evapo- 
ration to  dryness.  On  re-dissolving  the 
chromic  acid  residum  in  water,  filtering 
and  evaporating  to  a  proper  degree,  50 
parts  of  chromic  acid  may  be  obtained  in 
crystals. 

This  acid  may  also  be  obtained  from 
chromate  of  lime,  formed  by  mixing  chro- 
mate of  potash  and  muriate  of  lime ; 
washing  the  insoluble  chromate  of  lime 
which  precipitates,  and  decomposing  it  by 
the  equivalent  quantity  of  oxalic  acid, 
or  for  ordinary  purposes  even  sulphuric 
acid  may  be  employed. 

Chromic  acid  is  obtained  in  quadrangu- 
lar crystals,  of  a  deep  red  color  ;  it  has  a 
very  acrid  and  styptic  taste.  It  reddens 
powerfully  litmus  paper.    It  is  delique- 


chr] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


97 


scent  in  the  air.  When  heated  to  red- 
ness it  emits  oxygen,  and  passes  into  the 
deutoxyde.  When  a  little  of  it  is  fused 
along  with  vitreous  borax,  the  compound 
assumes  an  emerald  green  color. 

CHRONOGRAPH,  Locke's  Electro  C. 
This  apparatus,  for  which  an  appropria- 
tion was  made  by  Congress,  has  been 
put  in  operation  at  the  National  Observa- 
tory Washington. 

The  clock  case  is  of  fine  Italian  marble, 
ornamented  with  glass  panels,  set  in 
silver  sashes.  The  dial  and  hands  are 
like  those  of  an  ordinary  clock,  but  the 
dial  is  cut  out  and  made  a  skeleton,  for 
the  purpose  of  giving  access  to  the  elec- 
trical works  behind  it.  The  pendulum 
is  made  throughout  of  glass  ;  to  compen- 
sate for  the  expansion  even  of  glass  by 
heat,  the  weight  of  the  pendulum  con- 
sists of  four  large  glass  tubes,  placed 
side  by  side,  like  organ  pipes,  all  filled 
four  or  five  inches  deep  with  quicksilver. 
The  suspension  of  the  pendulum  con- 
sists of  hardened  steel  cylinders,  rolling 
on  jewelled  planes  made  of  polished 
chrysolite.  The  mechanism  by  which 
the  electrical  contact  surfaces  are  kept 
clean  and  bright  is  very  ingenious  and 
was  suggested  to  Dr.  Locke  by  Prof. 
House  oi  New  York.  It  consists  of  a 
small  platinum  cylinder  which  is  kept 
revolving  with  a  wiper  to  keep  it  clean. 
Thts  cylinder  has  also  a  longitudinal  mo- 
tion, which  by  reciprocation  makes  the 
electrical  contacts,  which  occur  every 
second,  travel  in  a  spiral,  which  also  re- 
volves. The  result  is,  that  the  contacts 
are  made  every  second  for  36  days  with- 
out occuring  twice  in  the  same  place ; 
and  even  then  it  is  a  mere  chance  if  the 
contacts  are  recommenced  in  the  same 
track. 

Every  time  a  contact  is  made  a  slight 
mark  is  left,  by  electrical  action,  on  the 
platinum  surface ;  and  when  the  spiral 
revolution  has  been  completed,  the  cylin- 
der is  mai-ked  all  over  its  surface  by  geo- 
metric intersections. 

The  clock  contains  a  duplicate  interrup- 
ter or  electrotome,  which  may  be  brought 
into  action  when  desired.  It  consists  of 
a  little  tilt-hammer,  pivoted  concentri- 
cally with  the  pendulum,  and  lifted  by  a 
little  arm,  or  its  equivalent,  projecting 
from  the  pendulum  itself. 

No  less  than  four  patents  have  been 
recently  taken  out  in  England  for  im- 
provements in  Clocks  moved  by  Electri- 
city. The  first  Electric  Clock  known  was 
invented  in  1815,  by  a  German  named 
Buzengeiger.  This  was  a  local  clock. 
6 


The  first  Electric  Clock  to  move  in  unison 
any  number  however  distant,  was  inven- 
ted by  Bain  in  1840.  Since  then  there 
have  been  a  great  number  of  modifica- 
tions such  as  combining  a  register  with 
the  clock,  which  is  a  most  important  im- 
provement. 

CHRONOMETER.  A  watch  of  pecu- 
liar construction,  and  great  perfection  of 
workmanship,  used  for  determining  geo- 
graphical longitudes,  or  other  purposes 
where  time  must  be  measured  with  ex- 
treme accuracy.  The  chronometer  differs 
from  the  ordinary  watch  in  the  principle 
of  its  escapement,  which  is  so  construct- 
ed that  the  balance  is  entirely  free  from 
the  wheels  during  the  greater  part  of  its 
vibration  ;  and  also  in  having  the  balance 
compensated  for  variations  of  tempe- 
rature. Marine  chronometers  generally 
beat  half  seconds,  and  are  hung  in  gim- 
bals, in  boxes  about  six  or  eight  inches 
square.  The  pocket  chronometer  does 
not  differ  in  appearance  from  the  ordi- 
nary watch,  excepting  that  it  is  generally 
a  little  larger.  Chronometers  are  of  im- 
mense utility  in  navigation  ;  and  ships 
going  on  distant  voyages  are  usually  fur- 
nished with  several,  for  the  purpose  of 
checking  one  another,  and  also  to  guard 
against  the  effects  of  accidental  derange- 
ment in  any  single  one.  The  accuracy 
whith  which  some  of  the  better  sort  of 
chronometers  have  been  found  to  perform 
is  truly  astonishing ;  the  error  in  a  two 
months'  voyage  not  exceeding  two  or 
three  seconds. 

Chronometers,  offered  to  the  British 
Government  to  purchase,  are  placed  in 
the  Greenwich  Observatory  in  the  first 
or  second  week  in  January,  and  ranged 
on  shelves  round  the  chronometer  room, 
and  each  is  daily  compared  with  the  astro- 
nomical clock,  and  its  rate  carefully 
noted.  This  is  continued  until  the  mid- 
dle of  July,  during  which  time  the  tempe- 
rature of  the  room  is  much  varied.  In 
the  coldest  weather  the  room  is  thrown 
open,  so  that  it  is  as  cold  inside  as  out ; 
and  in  summer  the  change  is  all  of  70°  of 
difference.  The  chronometers  are  also 
submitted  day  and  night  for  about  six 
weeks  to  80  degrees  heat,  raised  by  fire. 
This  is  the  usual  trial. 

Chronometers  are  more  in  use  in  Ameri- 
can vessels  than  in  those  of  any  other  na- 
tion. 

Mr.  Loseby  has  introduced  mercury 
into  the  chronometer  to  compensate  for 
the  loss  of  elasticity  in  the  balance  spring 
when  subjected  to  heat.  It  acts  equally 
by  its  fluidity  and  by  its  thermal  expan- 


98 


OTCLOPEDIA    OF    THE    USEFUL    ARTS. 


[cm 


sion,  and  has  been  favorably  reported  on 
after  trial,  by  the  Astronomer  Eoyal  of 
England. 

CHRYSOBERIL.  This  mineral  occurs 
in  small  rounded  masses,  and  in  crystals, 
it  is  very  hard,  transparent  or  translu- 
cent, and  of  different  shades  of  greenish 
yellow.  It  is  employed  in  jewelry.  It 
has  been  brought  from  Brazil ;  and  is  as- 
sociated in  the  sand  of  the  Ceylonese 
rivers  with  rubies  and  sapphires.  The 
cymo-pham  of  Kauy,  which  is  a  species  of 
chrysoberil,  consists  of  alumina  76*7, 
glucina  17*8,  oxide  of  iron  5-5. 

CHRYSOLITE.  A  crystallized  mineral, 
often  of  a  golden  yellow  color.  It  is  a 
ferriferous  silicate  of  magnesia,  and  is 
sometimes  used  in  jewelry. 

CHURN.  An  instrument  used  to  sepa- 
rate the  butter  out  of  milk.  So  long 
as  the  milk  is  alkaline  the  butter  will  not 
separate,  but  when  it  becomes  faintly 
acid  the  butter  commences  to  gather 
on  the  top.  Agitating  the  milk  by  in- 
troducing air  hastens  this  by  forming  lac- 
tic and  acetic  acids  in  the  milk. 

In  1850  Mr.  Z.  C.  Robins  of  St.  Louis, 
Mo.,  patented  a  telegraph  churn,  of  which 
the  following  figure  is  an  illustration. 

The  nature  of  this  invention  is  to  agi- 
tate the  cream  or  milk  by  the  operation  of 
the  rotation  of  the  beaters,  (formed  for 
that  purpose)  like  to  the  actionproduced 
by  knives  for  whipping  eggs.  The  speci- 
fication says : — 

I  produce  this  effect  by  forming  the 
beaters  on  the  agitator,  of  thin  slats  or 
boards,  A  A,  secured  to  radial  arms,  B  B, 
or  discs,  in  such  positions  as  to  bring 
their  sides  at  right  angles,  or  nearly  so, 
with  the  radii  of  the  agitator.  I  generally 
construct  the  agitator  of  four  series  of 
beaters,  as  represented  in  the  drawings, 
each  series  being  composed  of  two,  three 
or  more  beaters,  one  placed  within  the 
other,  with  narrow  spaces  be- 
tween each  beater. 

Unless  the  agitator  is  driven 
at  a  high  velocity,  the  particles 
of  milk,  &c,  are  not  thrown  off 
tangentially.  It  can  operate  in  a 
round  vessel  as  well  as  a  square 
one,  and  produces  butter  at  the 
usual  temperature,  in  about  ten 
minutes.  When  the  butter  has 
been  made,  it  is  collected  into  a 
roll  in  the  centre,  by  reversing 
the  motion. 

The  wording  of  his  claim  is : 
"  What  I  claim  is  the  series  of 
parallel  floats  or  beaters  A  A, 


j  formed  and  arranged  within  the  agitator, 
substantially  as  above  described,  so  that 
when  their  motion  is  reversed,  their 
thick  inclined  rear  edges  will  gather  the 
butter  into  a  roll  in  the  centre  of  the  agi- 
tator, substantially  as  herein  set  forth. 

CIDER.  A  fermented  liquor  made 
from  the  juice  of  apples.  Cider  is  made 
in  all  the  temperate  climates  of  the  world 
which  are  not  sufficiently  warm  for  ma- 
turing the  grape,  and  where  the  cold  is 
not  so  great  as  to  reduce  the  inhabitant? 
to  only  the  beer  produced  by  a  ferment- 
ed decoction  of  grain.  Cider  is  formed 
by  grinding  or  crushing  the  apples  when 
ripe,  either  in  a  circular  stone  trough  by 
a  stone  roller  turned  by  a  horse,  or  be- 
tween fluted  or  spiky,  and  afterwards 
between  smooth  rollers  of  wood  or  iron, 
driven  by  men.  The  apples,  including 
the  core  and  the  seeds,  being  reduced  to 
a  pulp  by  crushing  or  grinding,  the  mass 
is  put  into  a  hair  clotn  and  powerfully 
pressed  ;  and  the  liquor  which  runs  from 
it  is  put  into  casks,  where  it  is  allowed 
to  ferment,  the  casks  being  freely  expo- 
sed to  the  air  in  the  shade :  the  progress 
of  the  fermentation  is  then  carefully 
watched,  and  as  the  sediment  has  subsi- 
ded the  liquor  is  racked  off;  on  the 
I  proper  time  being  chosen  for  doing  this 
'  depends  the  excellence  of  the  cider.  The 
best  cider,  other  circumstances  being  the 
same,  is  that  in  which  the  fermentation 
has  gone  on  slowly,  and  where  the  vinous 
fermentation  has  not  gone  so  far  as  to  be- 
come acetous.  The  check  to  fermenta- 
tion consists  in  racking  off  from  one  cask 
to  another.  Before  winter  the  casks  are 
removed  to  a  cellar,  and  by  the  following 
spring  the  liquor  is  fit  for  use,  or  bot- 
tling. 

The  value  of  apples  to  produce  this 
beverage  of  good  quality  is  proportionate 
to  the  specific  gravity  of  their  juice.    M. 


cla] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


99 


Couverchel  has  given  the  following  tahle, 
illustrative  of  that  proposition : — 

Juice  of  the  green  renette,  queen 

apple  (reinstte  verte)       .       .        .  1,084 

English  renette 1,080 

Red  renette 1,0  <  2 

Musk  renette 1,069 

Fouilletrayd 1,064 

Orange  apple 1,063 

Renette  of  Caux 1,060 

Water  1,000 

\\\  November,2,  340  kilogrammes  of 
apples  (2*  tons  English,  nearly)  are  sup- 
posed to  afford  1,000  litres  (220*  gallons) 
of  pute  eider;  and  600  litres  of  a  small  ci- 
der made  with  the  marc  mixed  with  water 
and  pressed.  But  many  persons  mix  all 
together,  and  thus  manuiacture  1,600  li- 
tres out  of  the  ahove  weight  of  fruit. 
In  France,  the  fermented  liquor,  as  soon 
as  it  is  clear,  is  often  racked  off  into  casks 
containing  the  fumes  of  burning  sulphur, 
whereby  it  ceases  to  ferment,  and  pre- 
serves much  of  its  sugar  undecomposed. 
It  is  soon  afterwards  bottled.  Average 
cider  should  yield  6  per  cent,  of  alco- 
hol on  distillation. 

Cider-apples  may  be  distributed  into 
three  classes,  the  sweet,  the  bitter,  and 
the  sour.  The  second  are  the  best ;  they 
afford  a  denser  juice,  richer  in  sugar, 
which  clarifies  well,  and  when  fermented 
keeps  a  long  time;  the  juice  of  sweet 
apples  is  difficult  to  clarify ;  but  that  of 
the  sour  ones  makes  bad  cider.  Late  ap- 
ples are  in  general  to  be  preferred. 

Frederick  Falkener,  in  the  fourth  vol- 
ume of  the  Royal  Agricultural  Journal  of 
England,  adverts  judiciously  to  the  ne- 
cessity of  the  presence  of  alkaline  and 
earthy  bases,  in  the  soils  of  all  deciduous 
trees,  and  especially  of  such  as  produce 
acid  fruits. 

CINNABAE.  An  Indian  name,  given, 
according  to  Pliny,  to  a  mixture  of  the 
blood  of  the  dragon  and  elephant,  and 
other  substances  of  similar  color.  It  is 
now  exclusively  applied  to  the  red  pig- 
ment called  vermilion.  It  is  a  bisvlphuret 
of  mercury,  composed  of  200  mercury-f- 
32  sulphur. 

CINNAMON.  The  bark  of  the  Cin- 
namomum  zeylanicum.  This  tree  is  a  na- 
tive of  Ceylon,  whence  the  finest  cinna- 
mon is  obtained ;  it  is  of  an  astringent 
and  highly  aromatic  and  warm  flavor, 
and  yields  by  distillation  an  extremely  fra- 
grant and  pungent  volatile  oil,  kept  for 
pharmaceutical  use  under  the  name  of 
oil  of  cinnamon.  An  inferior  kind  of 
cinnamon  is  often  met  with  in  commerce, 
which  is  remarkably  deficient  in  flavor. 


CINNAMON  STONE.  (So  called  from 
its  color.)  A  silicate  of  lime,  alumine, 
and  oxide  of  iron,  from  Ceylon.  It  oc- 
curs massive  and  in  rounded  pieces  in 
the  sand  of  rivers  ;  some  of  these  are  oc- 
casionally cut  and  polished  for  jewelry. 

CITRIC  ACID.  The  acid  of  lime  and 
lemon  juice.  It  is  largely  made  for  do- 
mestic use  and  for  calico  printing.  The 
juice  is  saturated  with  lime  to  separate 
the  mucilage  and  extraneous  matters. 
The  citrate  of  lime  so  formed  is  treated 
with  oil  of  vitriol,  which  taking  the  lime 
to  form  sulphate  of  lime  sets  the  citric 
acid  free  :  this  is  treated  with  water,  and 
evaporated  and  crystallized. 

CIVET.  A  brown  semifluid  contained 
in  a  gland  near  the  anus  of  the  Viverra 
Civetta  or  civet  cat.  The  odor,  unless 
dilute,  is  very  unpleasant,  combined 
with  other  perfumes. 

CLARET.  A  term  applied  to  several 
of  the  Bordeaux  wines.  An  excellent 
claret  is  now  manufactured  in  Texas  from 
the  Mustang  grape.  As  many  as  five 
barrels  have  heen  made  upon  a  single 
plantation.  The  spontaneous  production 
of  this  grape  in  Texas  exceeds  all  belief. 
Thousands  of  hogsheads  of  wine,  nowise 
inferior  to  French  claret,  could  be  manu- 
factured every  year  from  this  hardy,  na- 
tive grape. 

CLAY.  In  chemistry,  a  term  gene- 
rally applied  to  a  variety  of  plastic  earthy 
compounds  of  different  colors,  and  hav- 
ing much  attraction  for  water.  They  are 
essential  in  the  manufacture  of  pottery, 
and  consist  of  silica,  with  variable  quan- 
tities of  alumina,  and  generally  some  ox- 
ide of  iron. 

Clay.  In  agriculture,  one  of  the  most 
common  ingredients  that  enter  into  the 
composition  of  soils.  Indeed,  it  may  be  as- 
serted that  no  soil  whatever  will  maintain 
its  fertility  for  any  length  of  time  without 
a  due  proportion  of  clay  in  its  composi- 
tion. The  most  fertile  soils  in  the  world 
are  the  alluvial  deposits  on  the  banks  of 
rivers ;  and  these,  in  an  agricultural 
sense,  all  belong  to  clayey  soil.  In  many 
cases  the  clays  of  agriculture  are  inti- 
mately united  with  calcareous  earths,  and 
in  others  with  sands ;  but  in  both  cases 
these  earths  are  in  such  a  state  of  minute 
division,  that  the  mixture  has  all  the  ap- 
pearance and  the  mechanical  properties 
of  a  strong  clay,  and  they  are  treated  by 
cultivators  accordingly  ;  and  these,  when 
examined,  are  found  in  many  cases  to 
contain  a  considerable  proportion  of  lime, 
and  in  others  of  sand.  The  best  wh*s,ts 
are  every  where  grown    on    calcareous 


100 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[COA 


clays ;  and  also  the  best  fruits  and  flow- 
ers of  the  Eosaceous  kind,  such  as  ap- 
ples, pears,  plums,  cherries,  roses,  &c. ; 
but  it  is  remarkable  that  the  grape,  when 
grown  on  clayey  soil,  produces  neither 
high-flavored  fruit  nor  good  wine. 

CLAYEY  SOIL.  Soil  in  which  clay 
is  the  principal  earthy  ingredient.  _  Soils 
of  this  description  when  first  subjected 
to  cultivation  are  expensive  to  labor,  and 
uncertain  in  their  produce;  but  after 
they  have  been  drained,  cultivated, 
limed,  and  manured  for  two  or  three  ge- 
nerations, they  become  the  most  fertile 
of  all  soils,  producing  immense  crops  of 
wheat,  beans,  clover,  rye-grass,  &c. 

CLOCK.    (See  Watoh.) 

CLOTH.  (See  Textile  Fabrics  and 
Weaving.) 

Cloth,  incombustible.  At  a  late  meet- 
ing of  the  British  Association,  Sir  Da- 
vid Brewster  read  a  paper  "  On  a  speci- 
men of  incombustible  cloth,  for  the 
dresses  of  ladies  and  children,  manufac- 
tured in  Dundee,  Scotland,  by  Mr. 
Latts."  This  cloth  is  printed  calico,  of 
which  several  specimens  were  prepared 
by  immersion  in  phosphate  of  magnesia. 
When  inflamed  it  soon  went  out  without 
the  flame  spreading,  and  Sir  David  stated 
that  a  spark  of  red  coal  would  not  ignite 
it.     ' 

Cloth,  Vulcanized  IndiaEubber  (pa- 
tented). Mix  15  parts  of  golden  sulphuret 
of  antimony  with  100  parts  of  India  rub- 
ber, and  when  it  is  thoroughly  "  masti- 
cated" as  known  to  manulacturers,  the 
articles  are  to  be  made  up  and  then  sub- 
mitted to  heat  in  a  boiler  under  pressure 
at  a  temperature  varying  from  260°  to 
280°  Fahrenheit. 

Cloth,  or  Silk  French  Waterproof. 
The  following  is  the  process  adopted  by 
M.  Collet :— Take  1  lb.  of  linseed  oil,  li 
lb.  of  white  lead,  1  oz.  of  umber,  and  a 
little  garlic;  boil  these  ingredients  for 
12  hours  over  a  slow  fire,  and  when  this 
composition  acquires  a  skin  upon  its 
surface,  it  is  fit  for  use.  The  cloth  or 
silk  is  then  to  be  immersed,  being  pre- 
viously spread  over  a  frame,  then  hung 
up  to  dry,  and  afterwards  rubbed  smooth 
with  pumice  stone. 

The  material  is  next  to  be  coated  with 
another  composition,  prepared  in  the  fol- 
lowing manner  : — Take  1  lb.  of  linseed 
oil,  1  oz.  litharge,  4  drachms  of  sulphate 
of  zinc,  and  4  oz.  of  white  lead,  calcined 
to  a  yellow  color :  boil  these  in  an  iron 
pot  until  they  assume  the  consistence  of 
paste.  This  preparation  is  then  to  be 
spread  over  the  cloth  on  the  side  of  it, 


and  then  dried  in  a  heated  chamber.  For 
covering  of  silk  this  operation  should  be 
repeated.  Oil-skin  cloth,  perfectly  flexi- 
ble and  waterproof,  is  thus  produced. 

COAL.  This  highly  important  sub- 
stance is  found  in  beds  or  strata  in  that 
group  of  the  secondary  rocks  which  in- 
cludes the  red  sandstone  and  mountain 
limestone  formations,  and  which  is  com- 
monly called  the  carboniferous  group,  or 
coal  measures.  From  the  peculiarities  of 
their  depositions  they  are  often  spoken 
of  under  the  names  of  coal  basins,  and 
coalfields.  There  are  two  or  three  points, 
and  those  of  much  theoretical  importance, 
respecting  the  origin  of  coal,  on  which 
geological  authorities  are  nearly  unani- 
mous .  The  one  is,  that  our  present  coal 
is  exclusively  of  vegetable  origin,  formed 
apparently  from  the  destruction  of  vast 
forests ;  and  the  prodigious  quantities  of 
timber  drifted  by  some  of  the  great 
rivers  of  the  world  into  the  present 
ocean  render  it  not  improbable  that  a 
similar  formation  may  now  be  carrying 
on  in  the  depths  of  certain  parts  of  the 
sea.  Secondly,  from  the  nature  of  the 
preserved  vegetables  it  appears  probable 
that  the  climate  of  these  parts  was  not 
merely  tropical,  but  ultratropieal.  It  may 
also  be  inferred  that  the  coal  strata  were 
deposited  in  the  neighborhood,  and  often 
probably  upon  the  very  verge  of  exten- 
sive tracts  of  dry  land  ;  for  the  trees  that 
are  found  in  coal  strata  are  often  like 
those  of  our  submarine  forests,  as  far  as 
position  goes.  And,  finally,  the  deposits 
of  coal  appear  afterwards  to  have  been 
elevated,  and  often  singularly  dislocated 
and  contorted  by  forces  acting  from  be- 
low, and  probably  of  a  volcanic  nature. 

In  some  coal  fields  there  are  appear- 
ances which  justify  the  term  coal  basin ; 
they  are  of  limited  extent,  frequently  dip 
as  it  were  to  a  common  centre,  and  con- 
sist of  various  beds  of  sandstone,  shale, 
and  coal,  irregularly  stratified ;  and 
sometimes  mixed  with  conglomerates, 
showing  a  mechanical  origin. 

That  "these  deposites  have  taken  place, 
and  that  the  change  of  wood  into  coal 
has  often  been  effected  under  great  pres- 
sure, and  often  under  the  pressure  of 
heat,  seems  evident  from  the  appearance 
of  some  of  the  vegetable  masses,  and  al- 
so from  the  manner  in  which  the  carbu- 
retted  hydrogen  escapes  in  the  form  of 
blowers  and  eructations  from  the  strata, 
as  if  pent  up  in  their  cavities  fender  vast 
condensation,  and  even  sometimes,  per- 
haps, in  a  liquid  form. 

Though  there  are  often  many  bods  and 


cob] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


101 


Beams  of  coal  in  one  field,  it  is  seldom 
that  many  of  them  are  worked.  They 
are  generally  of  uniform  thickness 
through  a  great  extent,  hut  are  some- 
times subject  to  irregularities.  When 
less  than  two  feet  thick  they  are  sel- 
dom worked  to  any  great  extent.  The 
nature  of  the  upper  stratum,  or  stony 
matter  of  the  roof,  is  very  important :  if 
compact,  it  is  secure  from  falling,  and 
keeps  out  water;  if  loose,  the  expenses 
incurred  in  supporting  it  absorbs  the 
profits  of  the  coal. 

The  Beds  of  Coal  in  the  U.  S.  are  numer- 
ous and  extensive,  embracing  the  whole 
country  from  the  border  of  New  Bruns- 
wick to  Tuscaloosa  in  Alabama,  and  from 
the  Allcghanies  to  Vancouver's  Island. 
The  coal  is  of  both  kinds,  anthracitic  and 
bituminous.  The  former  existing  on  the 
slope  of  the  Alleghanies,  where,  by  up- 
heaval of  heated  mineral  masses,  the  bitu- 
men has  been  expelled,  and  the  coal  con- 
verted into  anthracite.  The  bitumen  in 
coal  increases  as  the  beds  pass  westward 
toward  the  Mississippi,  where  as  well  as 
on  the  Pacific  shores,  the  quantity  of 
bitumen  is  equal  to  that  in  English  sea- 
coal.  The  geological  survey  of  the  state 
of  New  York  has  not  brought  to  light 
any  important  deposit  of  coal  in  that 
state  ;  but  it  has  been  stated  in  the  Al- 
bany livening  Journal  of  1850,  that  a  seam 
of  coal,  four  feet  in  thickness,  has  been 
discovered  by  Mr.  J.  N.  Cutler,  of  that 
city,  in  Coeymans — a  few  miles  only  from 
Albany,  on  the  farm  of  a  Mr.  Vanduzee. 
It  is  believed  to  extend  through  Albany, 
Green,  and  Schoharie  counties. 

The  three  great  coal-fields  in  the  country 
are : — the  Ohio,  740  miles  long,  and  180 
wide,  covering  an  area  of  60,000  square 
miles ;  the  Illinois  coal-field,  covering 
50,000  square  miles ;  and  the  Michigan, 
15,000  square  miles.  Besides  these,  there 
are  the  numerous  anthracitic  basins  in 
Pennsylvania  and  Virginia,  the  furthest 
being  100  miles  S.E.  of  the  margin  of  the 
Ohio  coal-field.  In  passing  across  the 
coal-fields  there  is  a  gradual  diminution 
of  the  bitumen  eastward.  The  coal  of 
every  kind  rests  on  the  same  basis  of 
rock,  with  the  same  fossils  distributed 
through  it,  and  the  particular  coal-fields 
can  be  identified  even  when  separated 
by  an  interval  of  50  miles.  The  anthra- 
cite field  is  5000  feet  deep,  and  contains 
50  seams  of  coal.  The  bituminous  coal- 
field of  Ohio  is  2,800  feet  deep,  3,000,000 
tons  of  anthracite,  and  1,000,000  tons  of 
bituminous  coal  are  raised  yearly.  The 
anthracite    coal-mines    on   the    Lehigh 


River,  Pa.,  are  worked  like  an  open  quar- 
ry on  the  slope  of  a  mountain,  rising  900 
feet  above  the  river.  The  coal  is  60  feet 
thick,  and  surrounds  the  quarry  in  black 
glistening  walls,  capped  by  40  feet  of  yel- 
low sandstone,  and  is  conveyed  by  a  self- 
acting  railway  for  eight  miles  down  a  de- 
clivity, from  100  to  140  feet  per  mile,  the 
whole  of  obtaining  being  about  4  cents  a 
ton  ;  when  quarried  to  some  distance  the 
bed  splits  up  into  branches.  The  anthra- 
cite district  extends  across  two  counties, 
Luzerne  and  Schuylkill.  At  Portsmouth, 
R.  I.,  abed  of  anthracite  has  been  worked 
for  25  years  back.  A  mine  of  anthracite 
has  been  open  in  Worcester,  Mass.,  at 
the  head  of  the  Blackstone  Canal.  The 
cost  of  transport  of  a  ton  of  coal  is — 

From  Maunch  Chunk  to  Philadelphia  $1  93 
From  Maunch  Chunk  to  New  York  .  2  42 
From  Penham  to  Philadelphia  .  .  I  93 
From  Penham  to  New  York  .        .    2  55 

The  value  of  coal  exported  in  1850  was 
$167,090.  The  coal  imported  in  the  same 
year  was  180,439  tons,  value  $378,817. 

COBALT.  From  Kohold,  "  evil  influ- 
ence," applied  by  the  German  miners, 
who  considered  it  unfavorable  to  the 
presence  of  the  more  important  metals. 

Cobalt  is  a  brittle  metal  of  a  reddish 
gray  color ;  its  specific  gravity  is  7*8.  It 
fuses  at  a  temperature  a  little  below  that 
required  for  the  fusion  of  iron.  It  is 
magnetic.  When  heated  red  hot,  and 
freely  exposed  to  air,  cobalt  absorbs 
oxygen.  Its  equivalent  number  is  30 ; 
and  the  salifiable,  or  protoxide  of  cobalt, 
consists  of  30  cobalt  +  8  oxygen  =  38  oxide 
of  cobalt.  The  oxide  of  cobalt  is  nearly 
black ;  but  when  in  the  state  of  hydrate', 
or  when  largely  diluted  by  fusion  with 
glass  or  borax,  it  produces  its  characteris-. 
tic  blue  color ;  and  as  this  color  is  perma- 
nent at  very  high  temperatures,  it  is  an 
invaluable  article  in  the  manufacture  of 
porcelain  and  pottery,  all  the  blue  colors 
of  which  are  derived  from  oxide  of  cobalt. 
When  fused  with  glass  it  communicates 
a  blue  tint  without  impairing  its  trans- 
parency. A  very  deep  blue  glass  of  this 
kind  when  finely  powdered  acquires  a 
pale  and  brilliant  color,  and  is  called  smalt. 
Impure  oxide  of  cobalt  is  known  in  com- 
merce under  the  name  of  zaffre.  Cobalt 
is  said  by  Stromeyer  to  exist  in  all  mete- 
oric iron,  although  in  very  small  quantity. 
In  its  ores  it  is  always  associated  with  ar- 
senic, and  zaffre  is  prepared  by  roasting 
these  native  arseniurets  of  cobalt. 

COCCOLITE.  A  mineral  of  a  concre- 
tional  or  granular  texture. 


102 


QYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[coc 


COCOON.  The  silken  case  which 
the  larvae  of  certain  insects  spin  for  the 
purpose  of  a  covering  during  the  period 
of  their  metamorphosis,  and  which  some 
spiders  prepare  as  a  protection  to  their 
ova  during  the  development  of  the 
young.  The  cod  or  cocoon  of  the  silk- 
worm is  a  well  known  example  of  the 
most  valuable  of  these  productions. 

COCCULUS  INDICUS.^  The  fruit  of 
the  Mervlspermum  cocculus,  imported  from 
the  East  Indies.  It  contains  a  poisonous 
principle,  which  has  been  termed  picro- 
toxia.  It  is  often  used  to  poison  hshes ; 
a  few  handfuls  of  it  ground  into  coarse 
powder,  and  thrown  into  a  pond,  bring 
the  fish,  in  the  course  of  a  few  hours,  to 
the  surface  in  an  intoxicated  or  poisoned 
state  ;  but  if  quickly  removed  into  fresh 
water,  they  recover.  It  is  sometimes  ad- 
ded to  ale  to  increase  its  stupefying  qua- 
lity. 

COCHINEAL.  The  Coccus  cacti.  This 
valuable  insect  was  first  introduced  into 
Europe  about  the  year  1523.     It  is  im- 

Eorted  from  Mexico  and  New  Spain.  It 
jeds  on  several  species  of  cactus.  It  is 
small,  rugose,  and  of  a  deep  mulberry 
color.  They  are  scraped  from  the  plants 
into  bags,  killed  by  boiling  water,  and 
dried  in  the  sun.  Those  are  preferred 
which  are  plump,  of  a  peculiar  silvery 
appearance,  and  which  yield  a  brilliant 
crimson  when  rubbed  to  powder.  Cochin- 
eal is  sometimes  adultered  by  the  admix- 
ture of  a  manufactured  article  composed 
of  colored  dough.  This  is  detected  by 
the  action  of  boiling  water,  which  dis- 
solves and  disintegrates  the  imitation, 
but  has  little  effect  upon  the  real  insect. 
The  principal  component  of  cochineal  is 
a  peculiar  coloring  matter,  which  has 
been  called  carminium  and  cochinelia.  It 
is  obtained  by  digesting  the  powder  of 
cochineal  first  in  ether,  which  takes  up 
fat,  and  then  in  alcohol,  which  dissolves 
the  cochinelia.  Acids  change  its  color 
from  crimson  to  an  orange  red,  and  alka- 
lies turn  it  violet.  When  mixed  with  re- 
cently precipitated  aluminous  earth,  it 
forms  a  beautiful  lake.  Cochineal  yields 
a  brilliant  scarlet  dye,  which  is  produced 
by  fixing  the  coloring  matter  of  the  in- 
sect by  a  mordant  of  alumina  and  oxide 
of  tin,  and  exalting  the  color  by  the  ac- 
tion ot  3upertartrate  of  potash.  {See 
Carmine  and  Dvking.) 

COCOA,  MANUFACTURES  FEOM. 
The  cocoa  manufactures  are  remarkable 
for  simplicity  of  the  process  resorted  to, 
and  for  the  usefulness  of  the  articles  pro- 
duced, in  many  instances,  from  materials 


formerly  thrown  away  as  useless.  The 
cocoa  nut  as  it  comes  from  the  tree  con- 
sists, first,  of  the  outer  husk,  composed 
of  fibres  matted  and  adhering  together ; 
secondly,  the  shell ;  and  thirdly,  the  ker- 
nel. The  manufacturers  up  to  the  present 
time  employed  only  the  outer  husk  and 
kernel.  Tlie  natives  of  India  have  long 
used  the  fibres  obtained  by  rotting  the 
outer  husk  till  the  fibres  can  be  separated 
by  beating  the  husks.  The  fibres  are 
spun  into  yarn  by  the  native  girls  and 
women,  by  rubbing  such  fibres  between 
the  palm  of  the  hand  and  the  surface  of 
the  leg ;  and  in  this  manner  is  made  the 
large  quantity  of  Coir  yarn  brought  into 
that  country,  and  used  for  weaving-cloths 
for  covering  passages  and  rooms,  and 
also  matting  for  various  uses.  Notwith- 
standing this  rude  mode  of  spinning  the 
fibres,  up  to  the  present  time  no  better 
means  have  yet  been  introduced ;  and  the 
whole  of  the  yarn  employed  in  England 
is  imported.  This,  however,  may  be  ac- 
counted for,  by  reason  of  there  having 
been  no  practical  mode  of  obtaining  the 
fibre  in  Britain  from  the  husks  till  very 
lately.  The  husks  are  beaten  to  obtain 
the  fibre,  which  consists  'of  three  descrip- 
tions :  first,  a  light  elastic  fibre  suitable 
for  stuffing  furniture ;  secondly,  a  coarser 
fibre  used  for  making  mats ;  and  thirdly, 
a  strong  fibre  used  for  brushes  and 
brooms.  The  husks  are  soaked  for  some 
time,  then  subjected  to  the  pressure  of 
grooved  rollers,  and  then  by  successive 
processes  of  carding,  by  revolving  cylin- 
ders armed  with  bent  teeth,  the  fibres  are 
combed  out,  the  separate  descriptions  of 
fibres  being  deposited  in  different  re- 
ceivers. The  uses  of  these  fibres  are  for 
making  brushes,  brooms,  mats,  and  mat- 
tresses. The  kernels  are  dried  in  the 
sun,  then  pounded  in  mills  to  extract  the 
oil ;  but  in  more  modern  times  the  dried 
kernel  has  been  pressed  between  mats  in 
powerful  presses.  The  oil  for  the  most 
part  is  sent  to  England,  and  was  formerly 
largely  employed  in  the  manufacturing  of 
candles.  The  oil  being,  when  it  comes 
to  London,  of  about  the  consistency  of 
lard,  requires  pressing  to  separate  the 
stearine  from  theelaine,  and  this  is  done 
between  mats  of  cocoa  nut  fibre  pressed 
in  powerful  presses.  The  stearine  was 
used  for  candles  at  first  alone,  then  in 
combination  with  stearic  acid  of  tallow, 
producing  what  are  called  composite 
candles  ;  and  it  was  the  introduction  of 
stearine  of  cocoa  nut,  combined  with 
stearic  acid,  which  constituted  the  first 
step  to  the  great  improvement  which  has 


com] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


103 


taken  place  in  the  manufacture  of  candles. 
The  larger  quantities  of  cocoa  nut  oil, 
however,  are  now  exported  to  France  to 
make  soap,  the  use  of  such  oil  in  candle 
making  being  now  for  the  most  part  sub- 
stituted bv  palm  oil.  It  has  lately  been 
proposed  m  Ceylon,  to  employ  the  juice 
of  the  cocoa  nut  tree  for  the  making  of 
sugar,  it  being  considered  that  each  tree 
is  capable  of  producing  upwards  of  one 
hundred  weight  per  annum,  and  that  an 
acre  of  cocoa  nut  trees,  requiring  little 
cultivation,  will  produce  at  least  twice  as 
much  sugar  as  an  acre  of  sugar-cane  re- 
quiring much  more  cultivation. 

COFFEE.  The  seed  of  an  evergreen 
shrub,  coffea  Arabica,  of  the  family  liuhi- 
acem.  It  rises  twenty  feet  high.  The 
berry  is  imported  from  Arabia,  the  East 
and  West  Indies.  In  Java  large  quanti- 
ties are  grown  and  exported. 

It  grows  upon  large  bushes,  and  the 
grains  of  coffee  are  formed  two  in  a  ber- 
ry, about  the  size  and  shape  of  our  com- 
mon plum.  The  skin  ot  the  berry  is 
about  as  thick  as  that  of  the  plum,  and 
the  color,  when  ripe,  a  pale  scarlet. 

The  bush  is  very  productive.  Every 
branch  is  loaded  with  the  berries,  which 
grow  two  in  a  place,  on  the  opposite  sides 
of  each  other,  and  about  an  inch  and  a 
half  apart.  When  ripe,  the  skin  bursts 
open,  and  the  grains  of  coffee  fall  out 
upon  the  ground;  but  a  more  general 
way  is  to  spread  something  tinder  the 
bush,  and  shake  the  coffee  down.  After 
the  outer  skin  is  taken  off  there  remains 
a  kind  of  husk  over  each  kernel,  which  is 
broken  off  (after  being  well  dried  in  the 
sun)  by  heavy  rollers.  The  coffee  after 
this  needs  winnowing,  in  order  to  be 
freed  from  the  broken  particles  of  the 
bush.  It  has  been  said  by  some  writers 
that  one  bush  will  not,  with  another, 
average  more  than  a  pound  of  coffee. 

Coffee  might  be  cultivated  with  advan- 
tage in  Florida. 
The  analysis  of  the  raw  berry  affords 

Cellular  matter, 34 

Moisture, 12 

Fatty  matters, 10  to  13 

Glucose  dextrin, 15*5 

Legumen  and  casein, 3 

Caffein, 3*5  to  5 

Nitrogenized  matters, 8 

Essential  oil  and  aromatic  principles,        -005 
Potash,  lime,  magnesia,  phosphoric  ) 
and  sulphuric"  acids,  silica  and  V      6-697 
chlorine, ) 

In  100  parts. 
The  change  coffee  undergoes  by  roast- 


ing is  not  fully  understood ;  some  of  the 
essential  oils  are  driven  off,  and  the  berry 
is  charred ;  the  peculiar  aroma  is  deve- 
loped, which  is  soluble  in  water,  and  is 
acid. 

COKE.  The  charcoal  obtained  by 
heating^  coal  with  the  imperfect  access  of 
air,  or  by  its  distillation.  The  former  is 
usually  called  oven  coke;  the  latter  gas 
coke,  being  abundantly  produced  in  gas- 
works. The  weight  of  coke  usually 
amounts  to  between  60  and  70  per  cent. 
of  the  coal  employed.  Coke  is  a  valuable 
fuel  for  many  purposes  in  the  arts. 

COLCOT1IAE.  Brown  peroxide  of 
iron.     (See  Rouge.) 

COLOPIIANY.  The  dark  colored  re- 
sin which  remains  after  the  distillation  of 
oil  of  turpentine. 

COLUMBIUM.  A  metal  discovered 
by  Mr.  Hatchett  in  1801,  in  a  mineral 
from  Massachusetts  in  North  America. 
It  has  since  Deen  found  in  a  Swedish 
mineral  called  tantalite,  but  its  ores  are 
extremely  rare.  It  is  acidifiable,  and 
hence  the  peroxide  has  been  termed  Co- 
lumbia acid. 

COLZA,  OIL  OF.  The  oil  expressed 
from  the  seed  of  the  Brassica  oleracea,  a 
species  of  cabbage.  Colza  oil  is  much 
used  in  France  and  Belgium  for  burning 
in  lamps  and  other  purposes. 

COMB.  The  name  of  an  instrument 
made  of  a  thin  plate,  either  plane  or 
curved  of  wood,  horn,  tortoise-shell, 
ivory,  bone,  or  metal,  cut  out  upon  one 
or  both  of  its  sides  or  edges,  into  a  series 
of  somewhat  long  teeth,  not  far  apart ; 
which  is  employed  for  disentangling, 
laying  parallel  and  smooth  the  hairs  of 
man,  horses,  or  other  animals. 

A  thin  steel  saw  bow,  mounted  in  an 
iron  or  wooden  handle,  is  the  implement 
used  by  the  comb-maker  to  cut  the  bone, 
ivory,  and  wood,  into  slices  of  from  a 
twelfth  to  a  quarter  of  an  inch  thiok,  and 
of  a  size  suitable  to  that  of  the  comb. 
The  pieces  of  tortoise-shell  as  found  in 
commerce  are  never  flat,  or,  indeed,  of 
any  regular  curvature,  such  as  the  comb 
must  have.  They  are  therefore  steeped 
in  boiling  water  sufficiently  long  to  soften 
them,  and  set  to  cool  in  a  press  between 
iron  and  brass  moulds,  which  impart  to 
them  the  desired  form  which  they  pre- 
serve after  cooling.  After  receiving  their 
outline  shape  and  curvature,  by  proper 
flat  files  or  fine  rasps,  the  place  of  the 
teeth  is  marked  with  a  triangular  file, 
and  then  the  teeth  themselves  are  cut 
out  with  a  double  saw,  composed  of  two 


104 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[com 


thin  slips  of  tempered  steel,  such  as  the 
main-spring  of  a  watch,  notched  with 
very  iine  sharp  teeth.  These  slips  are 
mounted  in  a  wooden  or  iron  stock  or 
handle,  in  which  they  may  be  placed  at 
different  distances,  to  suit  the  width  of 
the  comb-teeth.  A  comb-maker,  how- 
ever, well  provided  in  tools,  has  an  as- 
sortment ot  double  saws  set  at  every  or- 
dinary width.  The  two  slips  of  this  saw 
have  their  teeth  in  different  planes,  so 
that  when  it  begins  to  cut,  the  most 
prominent  slip  alone  acts  ;  and  when  the 
teeth  of  this  one  have  fairly  entered  into 
the  comb,  the  other  parallel  blade  begins 
to  saw.  The  workman,  meanwhile,  has 
fixed  the  plate  of  tortoise-shell  or  ivory 
between  the  flat  jaws  of  two  pieces  of 
wood,  like  a  vice  made  fast  to  a  bench, 
so  that  the  comb  intended  to  be  cut  is 
placed  at  an  angle  of  45°  with  the  hori- 
zon. He  now  saws  perpendicularly, 
forming  two  teeth  at  a  time,  proceeding 
truly  in  the.  direction  of  the  first  tracing. 

Dr.  Ure  mentions  a  much  better  mode 
of  making  combs,  which  is  to  fix  upon  a 
shaft  or  arbor  in  a  lathe  a  series  of  circu- 
lar saws,  with  intervening  brass  washers 
or  discs  to  keep  them  at  suitable  dis- 
tances ;  to  set  in  a  frame  like  a  vice,  in 
front  of  these  saws,  the  piece  of  ivory  or 
horn  to  be  cut ;  and  to  press  it  forward 
upon  the  saws  at  an  angle  of  45  degrees, 
by  means  of  a  regulated  screw  motion. 
Wli  en  the  teeth  are  thus  cut,  they  are 
smoothed  and  polished  with  files,  and 
by  rubbing  with  pumice-stone  and  tri- 
p'oli. 

Mr.  Bundy,  of  Camden  Town,  Eng- 
land, obtained  a  patent  so  long  ago  as 
1796,  for  an  apparatus  of  that  kind,  which 
had  an  additional  arbor  fitted  with  a  se- 
ries of  circular  saws,  or  rather  files,  for 
sharpening  the  points  of  the  comb-teeth. 

More  recently,  Mr.  Lyne  has  invented 
a  machine  in  which,  by  means  of  pres- 
sure, two  combs  are  cut  out  at  once  with 
chisels  from  any  tough  material,  such  as 
horn  or  tortoise-shell,  somewhat  softened 
at  the  moment  by  the  application  of  a 
heated  iron  to  it.  The  piece  of  horn  is 
made  fast  to  a  carriage,  which  is  moved 
forward  by  means  of  a  screw  until  it 
comes  under  the  action  of  a  ratchet- 
wheel,  toothed  upon  a  part  of  its  circum- 
ference. The  teeth  of  this  wheel  bring 
a  lever  into  action,  furnished  with  a 
chisel  or  knife,  which  cuts  out  a  double 
comb  from  the  flat  piece,  the  teeth  of 
which  combs  are  opposite  to  each  other. 
By  this  means,  no  part  of  the  substance 
is  lost,  as  in  sawing  out  combs.      The 


1  same  carriage  may  be  used,  also,  to  bear 

'  a  piece  of  ivory  in  the  hard  state  toward 

a  circular  saw,  on  the  principles  above 

explained,  with  such  precision,  that  from 

J  80  to  100  teeth  can  be  formed  in  the 

space  of  one  inch  by  a  proper  disposition 

j  of  the  tool. 

Bullocks'  horns,    after   the    tips    are 
I  sawed  off,  are  roasted  in  the  flame  of  a 
|  wood  fire,  till  they  are  sufficiently  soft- 
I  ened ;  when  they  are  slit  up,  pressed  in 
i  a  machine  between  two  iron  plates,  and 
[  then  plunged  into  a  trough  of  cold  water, 
I  whereby  they  are  hardened.     A  paste  of 
!  quicklime,  litharge,  and  water,  is  used  to 
!  stain  the  horn  to  resemble  tortoise-shell. 
COMBINATION.      A  chem'-al  term 
j  which  denotes  the  intimate  union  of  dis- 
similar particles  of  matter  into  a  homo- 
geneous-looking compound,  possessed  of 
properties  generally  different  from  those 
of  the  separate  constituents. 

COMBUSTIBLE.  Any  substance 
which,  exposed  in  the  air  to  a  certain 
temperature,  consumes  spontaneously 
with  the  emission  of  heat  and  light.  All 
such  combustibles  as  are  cheap  enough 
for  common  use  go  under  the  name  of 
Fuel ;  which  see.  Every  combustible 
requires  a  peculiar  pitch  of  temperature  to 
be  kindled,  called  its  accendible  point. 
Thus  phosphorus,  sulphur,  hydrogen, 
carburetted  nydrogen,  carbon,  each  takes 
fire  at  successively  higher  heats. 

COMPASS.  A  name  given  to  instru- 
ments contrived  to  indicate  the  magnetic 
meridian,  or  the  position  of  objects  with 
respect  to  that  meridian.  According  to 
the  purposes  to  which  the  instrument  is 
chiefly  applied,  it  becomes  the  mariner's 
compass,  the  azimuth  compass,  the  varia- 
tion compass,  each  particular  application 
requiring  some  peculiarity  of  construc- 
tion ;  but  whatever  modifications  it  may 
receive,  the  essential  parts  are  the  same 
in  all  cases.  These  are  a  magnetized  bar 
of  steel,  called  the  needle,  having  fitted  to 
it  at  its  centre  a  cap  which  is  supported 
on  an  upright  pivot,  made  sharp  at  the 
point  in  order  to  diminish  the  friction  as 
much  as  possible,  and  allow  the  needle 
to  turn  with  the  slightest  force.  The 
mariner' 8  compass  has  a  circular  card  at- 
tached to  its  needle,  which  turns  with  it ; 
and  on  the  circumference  of  which  are 
marked  the  degrees,  and  also  the  32 
points  or  rliomhs,  likewise  divided  into 
naif  and  quarter  points.  The  pivot  rises 
from  the  centre  of  the  bottom  of  the  cir- 
cular box,  called  the  compass  box,  which 
contains  the  needle  and  its  card,  and 
which  is  covered  with  a  glass  top  to  pre- 


coo] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


105 


vent  the  needle  from  being  disturbed  by 
the  agitation  of  the  air.  The  compass 
box  is  suspended  within  a  large  box,  by 
means  of  two  concentric  brass  circles  or 
gimbals,  the  outer  one  being  fixed  by  ho- 
rizontal pivots,  both  to  the  inner  circle 
which  carries  the  compass  box,  and  also 
the  outer  box,  the  two  sets  of  axes  being  at 
right  angles  to  each  other.  By  means  of 
this  arrangement  the  inner  circle,  with 
the  compass  box,  needle,  and  card,  al- 
ways retain  a  horizontal  position  notwith- 
standing the  rolling  of  the  ship. 

The  principal  requisites  of  a  compass 
are  intensity  of  directive  force,  and  sus- 
ceptibility. The  first  of  these  is  obtained 
by  constructing  the  needle  of  the  mate- 
rial and  form  best  suited  to  receive  and 
retain  the  magnetic  virtue.  A  number 
of  experiments  on  this  subject  were  made 
by  Coulomb,  and  more  recently  by  Cap- 
tain Kater,  an  account  of  which,  is  given 
in  the  Phil.  Trans,  for  1821.  Captain 
Kater  found  that  the  kind  of  steel  capable 
of  receiving  the  greatest  magnetic  force 
is  shear  steel ;  and  that  the  best  form  is 
that  of  a  lozenge  or  rhomboid  cut  out  in 
the  middle,  so  as  to  diminish  the  extent 
of  surface  in  proportion  to  the  mass,  it 
being  found  that  the  directive  force  of 
the  needle,  when  magnetized  to  satura- 
tion, depends  not 
on  the  extent  of 
surface,  but  on  the 
mass.  Beyond  a 
certain  limit  (about  five  inches)  no  addi- 
tional power  is  gained  by  increasing  the 
length  of  the  needle ;  and  needles  ex- 
ceeding a  very  moderate  length  are  apt 
to  have  several  consecutive  poles,  the  ef- 
fect of  which  is  to  produce  a  great  dimi- 
nution of  directive  force.  On  this  ac- 
count short  needles,  made  very  hard,  are 
to  be  preferred. 

The  azimuth  compass,  being  intended 
to  show  the  bearing  of  objects  in  respect 
of  the  magnetic  meridian,  has  its  circle 
divided  merely  into  degrees,  instead  of 
the  rhombs  used  in  navigation,  and  is 
provided  with  sights  to  allow  the  angles 
to  be  taken  more  accurately. 

The  variation  compass,  is  designed  to 
exhibit  the  diurnal  changes  in  the  devia- 
tion of  the  magnetic  from  the  true  me- 
ridian ;  and  the  needle  is  generally  made 
of  much  greater  length  than  the  mariner's 
compass,  in  order  to  render  minute  va- 
riations more  sensible. 

Mr.  Dent,  of  England,  in  1845,  made 

an  improvement  in  the  compass,  which 

consists  in  placing  the  iv  \gnetic  needles 

and  the  card  on  an  axis,  instead  of  the 

5* 


usual  mode  of  suspension,  the  point  be- 
ing higher  than  the  centre  of  gravity, 
and  subject  when  on  shipboard  to  the 
law  of  pendulous  bodies.  Mr.  Dent  has 
also  so  improved  the  azimuth  compass, 
that  by  turning  an  azimuth  180°,  it  effects 
the  correction  lor  collimation  ;  and  by  in- 
verting the  card,  it  being  engraved  on  both 
sides,  affords  the  means  or  determining 
the  error  of  the  zero  on  the  ard,  not  co- 
inciding with  the  magnetic  meridian. 

CONCRETE.  In  architecture  and  en- 
gineering a  mass  composed  of  stone 
chippings  or  ballast  cemented  together 
through  the  medium  of  lime  and  sand, 
usually  employed  in  making  foundations 
where  the  soil  is  of  itself  too  light  or  bog- 
gy, or  otherwise  insufficient  for  the  re- 
ception of  the  walls.  The  essential  qual- 
ity of  concrete  seems  to  be  that  the  ma- 
terials should  be  of  small  dimensions,  so 
that  the  cementing  medium  may  act  in 
every  direction  round  them,  and  that  the 
latter  should  on  no  account  be  more  in 
quantity  than  is  necessary  for  that  pur- 
pose. Architects  and  engineers  nave 
much  varied  the  proportions  of  lime  and 
sand  used.  If  the  lime,  which  should  be 
fresh  and  ground  to  powder,  be  good 
stone  lime,  it  will  bear  three  or  four 
times  its  measure  by  bulk  of  sand.  These, 
and  the  ballast  or  gallots,  as  the  stone 
chippings  are  called,  should,  be  thorough- 
ly turned  over  and  mixed  together.  If 
the  foundations  be  wet,  the  mixture  will 
want  very  little,  if  any  water;  indeed, 
sometimes  the  ballast  only  is  wetted,  and 
then  covered  over  with  the  lime  and 
sand.  It  is  then  filled  into  the  barrows, 
and  run  on  to  be  dropped  from  a  stage 
into  the  foundations.  This  latter  opera- 
tion should  be  performed  at  as  great  a 
height  as  possible  above  the  level  of  the 
trench,  in  order  that  the  whole  of  the 
different  particles  of  the  composition 
may  be  compressed  together  so  as  to  oc- 
cupy the  least  possible  space.  The  stones 
employed  should  not  exceed  the  size  of 
a  common  hen's  egg.  The  mass  very 
quickly  sets  and  becomes  extremely  hard. 

COOLEK.  An  apparatus  used  by 
brewers  and  distillers  for  cooling  worts. 
The  coolers  generally  consist  of  very  shal- 
low vessels  exposing  great  surface,  and 
placed  in  the  high  and  airy  parts  of  the 
brewery:  the  cooling  is  sometimes  as- 
sisted by  fans,  which  agitate  the  air 
over  their  surfaces.  Worts  are  also  oc- 
casionally cooled  by  causing  them  to  tra- 
verse metal  pipes,  which  are  surrounded 
by  a  counter-current  of  cold  water. 

COP-SPINNER.  A  piece  of  machinery 


106 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[coi 


for  this  purpose  was  exhibited  at  the 
fair  of  the  American  Institute,  N.  Y.,  in 
1849,  which  appears  to  combine  the  qua- 
lities of  the  throstle  and  mule  in  one 
frame.  The  rovings  from  bobbins,  at 
the  top  of  the  frame,  are  drawn  through 
drawing  rollers,  like  the  throstle-frame: 
and  from  the  drawing  rollers,  the  thread 
passes  at  once  to  a  small  traveller,  mov- 
ing around  a  ring  which  surrounds  the 
cop  spindle,  and  the  which  ring  has  a 
coping  motion  up  and  down,  to  build  the 
cop  on  the  spindle,  by  a  cam  gearing  be- 
low, connected  by  a  rocking  shaft  to  the 
main  driving  shaft.  The  whole  of  this 
machinery  occupies  no  more  room  than 
the  whole  throstle  frame  ;  no  carriage, 
like  the  mule  frame,  is  used ;  the  whole 
is  compact  and  simple,  and  it  does  its 
work  well.  It  is  asserted  that  it  will 
spin  100  per  cent  more  yarn  than  the  flyer 
spindle,  with  one  half  the  power,  com- 
pared to  the  quantity  produced ;  and  that 
2,820  spindles  produces  as  much  yarn  as 
4,600  spindles  on  the  old  machines. 
There  can  be  no  question  about  the  su- 
perior and  safe  speed  with  which  this 
machine  can  be  driven.  The  inventors 
and  proprietors  are  Mr.  John  C.  Dodge 
and    Sons,    Dodgeville,    Attleborough, 

Mnoa 

COPAIBA  or  COPIVI  BALSAM.  An 
exudation  from  the  Copaifera  officinalis, 
a  South  American  tree  :  it  is  a  liquid  re- 
sin, and  yields  by  distillation  a  consider- 
able quantity  of  a  pungent  volatile  oil. 
A  small  teaspoonful  taken  twice  a  day 
in  a  glass  of  water  proves  diuretic,  and  is 
of  use  in  the  cure  of  gleet  and  the  latter 
stages  of  gonorrhoea.  A  larger  dose  is 
aperient,  and  has  been  of  service  in  the 
treatment  oHhannorrhoids. 

COPAL.  A  generic  name  applied  to 
clear  gums?  This  substance  is  often 
improperly  called  gun  copal.  It  is  a  pe- 
culiar resin,  very  difficultly  soluble  in 
alcohol ;  hard,  brittle,  and  inodorous  ;  its 
specific  gravity  varies  from  1-04  to  1-13. 
It  is  the  produce  of  the  ETius  copalinum 
and  of  the  Elmocarpus  copaliferm  of  the 
East  Indies  :  a  third  kind  ot  copal  is  also 
brought  from  the  coast  of  Guinea.  It  is 
used  in  varnishes.  It  dissolves  in 
caoutchicine  diluted  with  alcohol. 

COPPER.  This  metal  was  known  at  a 
very  remote  period ;  and  in  the  early 
ages  of  the  world,  before  iron  was  in  use, 
copper  was  the  chief  ingredient  in  do- 
mestic utensils  and  instruments  of  war.  It 
is  an  abundant  metal,  and  is  found  native, 
and  in  many  ores  ;  of  these  the  most  im- 
portant are  the  varieties  of  pyrites,  which 
are  sulphurets  of  copper  and  iron.  There 


are  19  principal  ores  of  copper,  and  seve- 
ral subvarieties.  There  are  no  rules  by 
which  copper  ores  may  be  known  exter- 
nally, but  after  fusion  with  nitre,  water 
of  ammona  receives  a  deep  blue  tint 
from  any  cupreous  ore.  The  ores  are  na- 
tive copper,  sulphurets,  oxides,  silicates, 
carbonates,  sulphates,  phosphates,  clo- 
rides,  and  arseniates.  Native  copper  is 
found  abundantly  on  the  shores  of  Lake 
Superior,  both  in  Canada  and  this  coun- 
try, where  it  is  found  imbedded  in  trap, 
intruded  through  secondary  rocks ;  per- 
haps this  is  the  largest  district  of  native 
copper  in  the  world.  The  mass  disco- 
vered by  Schoolcraft  on  the  west  bank  of 
the  river  Onontagon  weighs  12,200  lbs.  It 
is  now  at  Washington.  "Large  masses  of 
pure  copper  are  quarried  at  the  several 
mines  in  that  region  fMinesota)  to  which 
attention  was  first  called  by  Dr.  Hutton. 

Some  of  these  veins  contain  10  per 
cent  of  silver,  which  brings  its  value  up 
to  between  four  and  five  thousand  dollars 
per  ton.  The  Eagle  Harbor  Mining 
Company  drifted  aiong  a  piece  of  na- 
tive copper  ninety  feet  without  finding 
its  length  and  four  feet  downwards, 
without  reaching  its  depth;  its  average 
thickness  was  18  inches.  The  veins  vary 
in  thickness  from  6  inches  to  2  feet 
branching  east  and  west,  in  small  strings 
2  inches  thick,  and  12  to  24  inches  long. 
The  trap  in  the  interstices  are  charged 
with  native  copper  to  about  50  per  cent. 
There  are  six  very  profitable  veins  in  this 
shore.  Dr.  Jackson  has  shewn  that  these 
mines  were  worked  by  the  native  Indians 
many  years  back.  Congress,  in  1817,  di- 
rected a  survey  of  these  mines  to  be 
made  ;  the  report  has  not  yet  been  sent 
in.  In  the  working  of  the  Cliff  and  Mine- 
sota mine  the  difficulty  has  been  to  get 
away  pieces  small  enough.  Seven  pieces 
taken  from  the  Cliff  mine  in  1850  weighed 
29,852  lbs.,  and  4  from  Minesota  weighed 
14,611  lbs.  The  latter  company  smelt 
their  copper  in  New  York.  The  copper 
is  chiselled  away  with  heavy  hammers. 

The  pyritic  ores  are  the  vitrious  copper 
ore,  which  consists  of  81  copper  and  19 
sulphur,  found  in  the  U.  S.  in  old  red 
sandstone.  The  purple  copper  ore  con- 
tains iron  with  sulphur  :  it  is  not  found 
in  quantity.  The  grey  copper  ore  con- 
sists of  copper  52,  iron  23,  and  14  sul- 
phur. It  occurs  plentifully  in  Kussia, 
Chili,  and  Mexico. 

Yellow  copper  ore  is  the  most  abun- 
dant ore,  found  plentifully  in  this  north- 
ern and  southern  continent.  It  contains 
copper  30,  iron  32,  sulphur  36  ;  lead  and 
arsenic  3. 


cot] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


107 


The  red  oxide,  or  tile  ore,  is  the  richest 
variety,  containing  88-5  per  cent  of  cop- 
per. It  occurs  in  Peru  and  Chili.  Azure 
copper  and  malachite  are  carbonates  ; 
they  are  found  in  Pennsylvania  and  Lake 
Superior.  The  finest  specimens  of  mala- 
chite are  from  the  Siberian  Ural  Chain  in 
Russia,  where  it  occurs  so  massive  that 
large  doors  30  feet  by  18  have  been  cut 
out  of  the  mineral,  and  are  now  exhibited 
in  the  Crystal  Palace,  London. 

The  ores  are  repeatedly  roasted  and 
fused  to  drive  off  the  sulphur,  and  the 
oxide  of  copper  is  ultimately  reduced  by 
the  joint  agency  of  heat  and  carbon.  Cop- 
per is  distinguished  by  its  color.  Its  spe- 
cific gravity  is  8'6.  It  is  ductile  and  mal- 
leable, and  requires  a  temperature  equal 
to  about  2000°  of  Fahrenheit's  scale  for 
its  fusion ;  that  is,  nearly  a  white  heat.  Ex- 
posed to  air  and  moisture,  copper  gradual- 
ly becomes  covered  by  a  green  rust ;  heated 
red-hot,  it  absorbs  oxygen,  and  is  super- 
ficially converted  into  a  black  oxide,  which 
is  the  basis  of  the  principal  salts  of  cop- 
per ;  it  consists  of  32  copper  and  8  oxy- 
gen. It  forms  blue  or  green  salts  with 
the  acids  ;  of  these  the  sulphate  of  copper, 
or  blue  vitriol,  is  a  good  example.  The 
salts  of  copper  are  poisonous ;  and  in 
consequence  of  the  use  of  copper  vessels 
for  culinary  purposes,  food  is  sometimes 
contaminated  by  them.  It  is  detected 
when  in  very  minute  quantities  by  the 
bright  blue  color  produced  by  the  addi- 
tion of  liquid  ammonia,  and  by  a  brown 
precipitate  with  ferrocyanate  of  potash. 
A  clean  plate  of  iron  dipped  into  a  solu- 
tion containing  copper  becomes  covered 
with  the  latter  metal  in  a  metallic  state. 

Two  improvements  in  the  smelting  of 
copper  ores  have  been  suggested.  One 
is  to  roast  the  sulphuretted  copper  ores 
with  salt.  The  sulphur  Is  converted  into 
sulphuric  acid,  which  seizes  on  the  soda 
of  the  salt.  Its  chlorine  passes  to  the 
copper,  forming  a  chloride,  which  can 
be  dissolved  out  by  water.  The  copper 
is  separated  from  this  solution  by  pieces 
of  iron  dropped  into  it. 

The  other  mode  is  by  roasting  to  con- 
vert the  ore  into  a  sulphate  of  copper, 
and  dissolve  this  in  water.  The  copper 
is  thrown  down  by  iron  as  in  the  first 
instance.     {See  Metallurgy.) 

Bronze  and  Bell  Metal  are  alloys  of  cop- 
per and  tin.  They  are  melted  in  cruci- 
bles, and  cast  in  charcoal  moulds.  An  alloy 
of  100  copper  and  4  of  tin  makes  a  good 
metal  for  medals. 

Copper  100,  and  tin  14,  affords  a  metal 
for  edge  tools  equal  in  hardness  to  steel. 
Cymbal  and  Gong  Metal  consists  of  copper 


I  100,  and  tin  25.  After  being  heated  it 
!  should  be  suddenly  cooled. 

Eor  White  Copper,  «ee  German  Silver. 

Copper  may  be  tinned  by  placing  a 
sheet  of  tin  on  a  well  polished  surface  of 
copper,  and  subjecting  them  to  a  strong 
heat,  a  little  resin  or  muriate  of  ammoni- 
um being  sprinkled  between  the  plates 
to  prevent  oxidation. 

COPPERAS.  Green  vitriol,  or  sul- 
phate of  iron. 

COPPERPLATE.  In  engraving,  a 
plate  of  copper  highly  polished  on  which 
an  engraving  is  made. 

CORAL.  A  calcareous  substance,  the 
covering  of  the  coral  insect.  It  :,s  fished 
up  in  the  Mediterranean,  Red,  and  Indian 
sens  ;  mostly  of  a  red  tint,  but  also  flesh 
colored,  or  white.  It  is  used  for  making 
necklaces,  crosses,  &c,  and  is  worked 
like  precious  stones.  It  is  composed  of 
carbonate  of  lime,  with  a  trace  of  phos- 
phate. The  debris  of  the  coral  animal 
washed  on  shore,  or  dredged  up,  forms  a 
valuable  manure. 

CORK.  The  bark  of  the  Quercus  liber, 
a  species  of  oak  which  grows  along  the 
shores  of  Mediterranean  Europe.  It  i9 
removed  from  the  tree  by  making  circu- 
lar incisions,  and  connecting  these  by 
longitudinal    ones;     the    bark    is    then 

Eeeled  off,  wetted  to  flatten  it  between 
oards  ;  it  is  then  fire  dried,  which  black- 
ens the  surface.  When  burned,  it  forms 
a  light  black  substance,  known  as  Span- 
ish black.  Corks  are  cut  with  the  pores 
laterally;  bungs  have  them  downwards, 
hence  they  do  not  keep  in  the  liquid  as 
well.  Cork  is  also  used  for  inner  soles, 
floats  in  water,  models,  and  false  limbs. 
Powdered  cork,  treated  with  alcohol, 
leaves  70  per  cent  of  suberine ;  treated 
with  nitric  acid,  it  is  changed  into  resin, 
OXalic  acid  and  suberic  acid. 

CORROSIVE  SUBLIMATE.  The  bi- 
cloride  of  mercury,  composed  of  200  mer- 
cury+72  chlorine.  It  is  an  acrid  poison 
of  great  virulence  :  the  stomach-pump 
and  emetics  are  the  surest  preventives 
of  its  deleterious  effects  when  accidental- 
ly swallowed  ;  white  of  egg  has  also  been 
found  serviceable  in  allaying  its  poison- 
ous influence  upon  the  stomach.  Its  spe- 
cific gravity  is  5*2.  It  requires  20  parts 
of  cold  water,  but  only  two  of  boiling 
water,  for  its  solution.     {See  Mercury.) 

CORUNDUM.  A  crystallized  or  mas- 
sive mineral  of  extreme  hardness,  and 
composed  of  nearly  pure  alumina ;  it  is 
usually  almost  opaque,  and  of  a  reddish 
color.     It  is  allied  to  the  sapphire. 

COTTON.  The  soft  vegetable  down 
in  the  seed  vessels  of  the  cotton  plant 


108 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[cot 


(gossypium  Tierhaceum),  cultivated  in  this 
country,  South  America,  the  East  and 
West  Indies,  and  Egypt.  It  is  an  annual 
plant,  which  forms  its  seed  in  pods, 
which  are  triangular,  and  have  each  three 
cells  ;  in  these  lie  the  downy  cotton.  The 
fibres  of  cotton  are  very  fine,  delicate, 
and  flexible  ;  under  the  microscope  they 
are  flat,  triangular,  and  somewhat  con- 
torted ;  their  sides  are  serrated,  which 
explains  the  cause  of  their  adhering  to- 
gether, and  enables  them  to  be  spun  into 
thread.  In  the  southern  states,  three 
kinds  are  cultivated :  the  nankeen  cotton, 
the  green  seed,  and  the  black  seed  cotton. 
The  two  first  are  upland  and  short  staple 
variety.  The  last  has  a  long  fine  staple. 
Two  machines  are  used  to  clean  the 
cotton  from  the  seed, — the  roller  gin  and 
the  saw  gin.  The  first  consists  of  two 
small  cylinders,  between  which  the  cotton 


is  drawn,  while  the  seed  is  prevented  by 
its  size  from  passing.  The  saw  gin,  in- 
vented by  E.  Whitney,  is  used  for  the 
black  seed,  which  adhere  too  strongly  to 
be  separated  by  the  rollers.  His  appa- 
ratus is  a  receiver,  fitted  on  one  side 
with  wires  an  eighth  of  an  inch  apart; 
between  these  pass  a  number  of  circular 
saws,  revolving  on  a  common  axis.  The 
cotton  is  caught  by  the  teeth  of  the 
saws,  and  drawn  through  the  grating, 
which  is  too  narrow  to  admit  the  seeds 
to  pass.  The  cotton  thus  separated  is 
swept  off  the  saws  by  a  revolving  brush  ; 
the  seeds  fall  out  at  the  bottom.  The  cot- 
ton crop  of  this  country  in  1848  was 
estimated  at  1,066,000,000  lbs.,  value 
$74,620,000.  The  following  is  a  tabular 
view  of  the  value  of  raw  and  manufac- 
tured cotton  for  the  last  five  years,  with  the 
amount  of  export  to  Britain  and  France. 


Raw  Cottcn. 

Home 
Manufactured. 

Exported  to  Great  Britain. 

Exported  to  France. 

Years. 

Raw  Cotton. 

Manufac. 
Cotton. 

Cotton  Wool. 

Manufac. 
Cotton. 

1846 
1847 
1848 
1849 
1850 

$42,707,341 
53,415,848 
61,998,294 
66,396,967 
71,984,616 

$  3,545,481 
4,082,543 
5,718,205 
5,933,129 
4,734,424 

$27,707,717 
35,841,265 
41,925,258 
47,444,899 
48,884,453 

$9,607 

6,765 
28 

2,591 
50 

$10,080,485 
10,381,318 
11,428,850 
10,185,713 
14,395,449 

$   216 

2,374 
539 

$296,563,066 

$53,013,762 

$201,803,592 

$19,041 

$56,471,798 

$3,229 

COTTON  MANUFACTURE  embraces 
so  many  operations,  each  of  which  is  per- 
formed in  various  ways,  and  by  mechan- 
ism variously  termed,  that  it  requires  a 
volume  of  ordinary  size  to  give  a  full  de- 
scription of  it.  It  is  impossible,  in  the 
limits  here  assigned,  to  give  more  than  a 
faint  outline  of  the  most  common  pro- 
cesses. 

The  first  process  is  that  of  separating 
and  spreading  it  out  in  a  light  uniform 
mass,  and  is  "termed  batting  and  scutch- 
ing, or  willeyingand  spreading,  according 
to  the  description  of  machinery  employed 
for  the  purpose.  This  machinery  consists, 
mainly,  of  revolving  beaters  which  beat 
the  cotton  against  gratings  or  screens, 
through  which  the  dirt,  sand  and  short 
broken  fibres  are  blown  by  fans. 

The  next  process  is  that  of  carding, 
which  serves  to  equalize  the  substance  of 
the  cotton,  and  dispose  the  fibres  in  a 


*  The  ginning  operation  is  always  |>ert'orine<l 
on  the  plantation,  or  IwHore  the  cotton  is  packeo* 
in  bales  for  transportation  to  the  place  where  it 
is  manufactured. 


parallel  direction.  The  carding  engine 
consists  of  a  revolving  cylinder  covered 
with  cards,  which  is  nearly  surrounded 
by  a  fixed  concave  framing  also  lined 
with  cards,  with  which  the  cylinder 
comes  in  contact.  From  the  cylinder, 
called  the  breaker,  the  cotton  is  taken 
out  by  the  motion  of  a  transverse  comb, 
called  thu  drffing  plate,  and  passes  through 
a  second  carding  in  the  finishing  cylinder. 
The  cotton  leaves  the  carding-engine 
in  the  state  of  a  delicate,  flat,  narrow  strip 
or  ribbon,  called  a  sliver  y  and  these  sli- 
vers have  now  to  be  converted  into  draw- 
ings, by  being  elongated,  narrowed,  and 
thinned  to  a  still  more  delicate  condition. 
This  process  is  one  to  which  Arkwright 
paid  particular  attention,  as  having  an 
important  influence  on  the  quality  of 
spun  cotton.  In  the  first  place  the  sli- 
vers are  collected  in  tall  cans,  generally 
either  four  or  six  in  number,  on  one  side 
of  the  drawing  frame,  and  are  from 
thence  carried  upwards  to  two  pairs  of 
rollers,  the  two  rollers  of  each  pair  re- 
volving in  contact.    Here  all  the  slivers  or 


cot] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


109 


cardings  are  collected  into  one  group,  and 
are  drawn  between  the  rollers  by  the  ro- 
tation of  the  latter.  Now  if  these  rollers 
are  revolved  equally  fast,  the  cotton 
would  leave  thein  with  the  same  united 
thickness  as  when  it  entered  ;  hut  the 
last  pair  revolves  quicker  than  the  first, 
so  as  to  draw  out  the  cotton  in  a  more 
attenuated  ribbon  ;  because  the  more 
slowly-revolving  rollers  do  not  supply 
the  material  fast  enough  for  the  main- 
tenance of  the  original  thickness.  This 
is  perhaps  the  most  important  principle 
in  the  whole  range  of  the  cotton  manu- 
facture ;  for  it  is  exhibited  alike  in  the 
present  process  and  in  the  next  two 
which  follow.  All  the  four  or  six  slivers 
are  connected  into  one  before  being 
Caught  between  the  rollers ;  and  after 
leaving  the  rollers,  the  united  "drawing1' 
passes  through  a  kind  of  trumpet-shaped 
funnel,  and  is  thence  conducted  into  a 
tall  can,  round  the  interior  of  which  it 
recoils  itself.  One  consequence  of  the 
drawing  process,  if  properly  conducted, 
is,  that,  the  drawing  is  perfectly  equal  in 
thickness  in  every  part,  and  formed  of 
parallel  fibres ;  and  in  order  to  insure 
this,  the  drawing  is  repeated  more  than 
once,  each  narrow  ribbon  being  "dou- 
bled" with  others  before  each  successive 
drawing. 


The  preliminary  spinning  process  is 
called  roving.  At  first  the  torsion  is 
slight  in  proportion  to  the  extension, 
since  the  solidity  of  the  still  coarse  sliver 
needs  that  cohesive  aid  only  in  a  small 
degree,  and  looseness  of  texture  must  be  I 


maintained  to  facilitate  to  the  utmost  the 
further  elongation. 

Fig.  33,  is  a  section  of  the  can  roving 
frame,  the  ingenious  invention  of  Ark- 
wright,  which,  till  within  these  14  years, 
was  the  principal  machine  for  communi- 
cating the  incipient  torsion  to  the  spongy 
cord  furnished  by  the  drawing  heads. 
It  differs  from  that  frame  in  nothing  but 
the  twisting  mechanism:  and  consists  of 
two  pairs  of  drawing  rollers,  a  and  b,  be- 
tween which  the  sliver  is  extended  in 
the  usual  way  ;  c  are  brushes  for  cleaning 
Uie  rollers ;  and  d  is  the  weight  which 
presses  the  upper  set  upon  the  lower. 
The  wiping  covers  (not  shown  here)  rest 
upon  a  b.  The  surface  speed  of  the  pos- 
terior or  second  pair  of  rollers  is  3,  4,  or 
5  times  greater  than  that  of  the  front  or 
receiving  pair,  according  to  the  desired 
degree  of  attenuation.  Two  drawn  sli- 
vers were  generally  united  into  one  by 
this  machine,  as  is  shown  in  the  figure, 
where  they  are  seen  coming  from  the  two 
cans  c  e,  to  be  brought  together  by  the 
pressure  rollers,  before  they  reach  the 
drawing  rollers  a  b.  The  sliver,  as  it  es- 
capes from  these  rollers,  is  conducted  into 
the  revolving  conical  lantern  g,  through 
the  funnel/ at  its  top.  This  lantern-can 
receives  its  motion  by  means  of  a  cord 
passing  over  a  pulley  k,  placed  a  little 
way  above  the  step  on  which  it  turns. 
The  motion  is  steadied  by  the  collet  of 
the  funnel/,  being  embraced  by  a  brass 
busk.  Such  a  machine  generally  con- 
tained four  drawing  heads,  each  mounted 
with  two  lanterns;  in  whose  side  there 
was  a  door  for  taking  out  the  conical  coil 
of  roving. 

The  bobbin  and  fly  frame  is  now  the 
most  common  roving  machine  for  fine 
spinning.  Its  main  feature  consists  of  a 
system  of  vertical  spindles,  on  each  of 
which  is  placed  a  reel  or  bobbin,  and  also 
a  kind  of  fork  called  a  "fly,"  still  farther 
removed  than  the  bobbin  from  the  axis 
of  the  spindle.  The  drawing  or  delicate 
silver  of  cotton  is  first  drawn  through  or 
between  rollers,  and  elongated  to  the  state 
of  a  roving  ;  then  this  roving  passes  down 
a  tube  in  one  prong  of  the  fork  or  fly, 
and  becomes  twisted  by  the  revolution  of 
the  fly  round  the  bobbin,  while  at  the 
same  time  the  twisted  roving  becomes 
wound  with  great  regularity  upon  the 
bobbin.  The  machine  in  fact  performs 
three  different  and  distinct  operations ; 
it  first  attenuates  the  "drawing"  to  a 
state  of  still  greater  thinness  and  delicacy 
than  it  had  before  ;  it  then  gives  to  the 
"roving"  thus  produced  a  slight  twist, 


110 


CYCLOPEDIA   OF    THE    USEFUL    ARTS. 


[cot 


sufficient  to  enable  the  fibres  to  cohere  ; 
and  lastly,  it  winds  this  twisted  roving 
upon  a  bobbin,  on  which  it  is  convenient- 
ly transferred  to  the  spinning-machine. 

The  next,  or  finishing  operation  is  that 
of  spinning.  One  of  the  earliest  machines 


e.  d  is  the  clasp  or  clove,  having  a  han- 
dle for  lifting  its  upper  jaw  a  little  way, 
in  order  to  allow  a  few  inches  of  the  soft 
roving  to  be  introduced.  The  compound 
d  being  now  pushed  forward  upon  its 
friction  wheels  to  a,  was  next  gradually 
drawn  backward,  while  the  spindles  were 
made  to  revolve  with  proper  speed  by  the 
right  hand  of  the  operative  turning  the 
fly-wheel  b.  Whenever  one  stretch  was 
thereby  spun,  the  clove  frame  was  slid 
home  towards  a  ;  the  spindles  being  si- 
multaneously whirled  slowly  to  take  up 
the  yarn,  which  was  laid  on  in  a  conical 
cop  by  the  due  depression  of  the  faller 
wire  at  a  with  the  spinner's  left  hand. 

The  machines  which  are  now  most  in 
use  for  spinning,  are  the  throstle,  or 
water-twist  frame,  and  the  self-acting 
mule,  which  are  both  so  perfect  as  to 
work  almost  without  the  aid  of  manual 
labor.  These  machines  are  so  complex  as 
to  preclude  the  possibility  of  rendering 
them  intelligible  here.  Suffice  it  to  say, 
that  the  principle  of  their  operation  is 
substantially  the  same  as  that  of  the  ma- 
chine described,  the  improvements  in- 
creasing the  amount  of  work  performed, 
improving  its  quality,  and  dispensing  in 
a  greater  degree  with  manual  labor. 

The  yarn  being  spun  into  either  fine  or 
coarse  thread,  is  applicable,  for  the  warp 
or  weft  in  woven  goods  ;  when  the  weav- 
ing is  done  at  home,  it  is  by  hand-loom  ; 
when  in  a  factory,  it  is  by  power-loom. 
This  process  will  be  followed  under 
Weaving  and  Textile  Fabrics. 

The  following  tables,  extracted  from  an 


employed  for  this  purpose,  was  the  jenny 
of  llargreaves,  which  is  represented  by 
the  following  cut.  By  this  machine  one 
person  was  enabled  to  spin  from  16 
to  40  threads  at  once.  The  soft  cords  of 
rovings  wound  in  double  conical  cops  up- 
on skewers,  were 
placed  in  the  in- 
clined frame  at  c ; 
the  spindles  for 
first  twisting  and 
then  winding-on 
the  spun  yarn 
were  set  upright 
in  steps  and  bush- 
es at  a,  being  fur- 
nished near  their 
lower  ends  with 
whorls,  and  end- 
ess  cords,  which 
were     driven    by 

fmssing  round  the 
ong  revolving 
drum  of  the  plate 
article  on  Cotton  Manufacture,  written  by 
Mr.  Dodge  for  the  Scientific  American, 
are  inserted  hers,  as  they  present  some 
valuable  results. 

A  Table  showing  the  number  of  Operatives 
employed  by  the  principal  cotton  manu- 
facturing establishments  in  the  United 
States,  together  with  the  annual  and  ag- 
gregate amount  of  wages  paid  the  same 
from  1838  to  1848,  inclusive. 


i  &£ 


Eft! 


9,287,200 
9,880,000 
10,275,200 
9,0S9,f>00 
10.868,000 
11,658,400 
13,041,000 
11,227,200 
14,S20,000 
16.796,000 
18,772,000 


4,368,000 
4,680,000 
4,836,000 
4,805,000 
5,148,000 
4,304,000 
6.240,000 
6,864,000 
7,176,000 
7,800,000 
8,4-M,000 


'13,655,200 
14,560,000 
15,111,200 
13,395,200 
16,016,000 
16,962,400 
19,281,600 
21,091,200 
21,996,000 
24,596,000 
27,196,000 


Total  aggregate  of  males  employed  in 
eleven  years,  208,800 ;  females,  702,000. 
Total  aggregate  wages  paid  to  females 
for  eleven  years,  $138,715,200  ;  males, 
$65,145,600.     Total,  $203,860,800. 

Average  No.  of  males  employed  per 
year,  for  eleven  years,  18,982 ;  females, 
63,818.  Average  aggregate  paid  females 
per  year  for  eleven  "years,  $12,610,472; 
males,  $5,922,327.     Total,  $18,532,800. 

The  chief  manufactures  of  cotton  are 
carried  on  in  the  New  England  States :  it 


cre] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


Ill 


is  only  of  late  years  that  manufactures 
have  sprung  up  in  the  South ;  at  the  pre- 
sent time  in  Georgia,  there  are  40  cotton 
mills  working  60,000  spindles,  and  using 
45,000  bales  of  cotton  per  annum.  In 
Tennessee  there  are  30  factories,  run- 
ning 30,000  spindles  and  700  looms,  and 
using  15,000  bales.  In  Alabama  there  are 
12  lactones,  working  15,580  spindles  and 
300  looms,  and  consuming  5,000  bales  of 
raw  cotton. 

A  Table  showing  the  number  of  Spindles  run, 
and  the  annual  increase  of  toorlc  in  U.  8. 


«!  n^      m    |NTo,  of  yiirds.  Increase 

.»ji        i  maniifiietur-  I  of  Xo.  of  J.'"** 
»!»*<**]  „,.  Ispin.Ji.s.   No.  ofyardB. 


1838!  1.422.000  409.200,000  185,000  51,000,000 
1839 '  1.521  >,< !00  501 ,500,000  93,000  32,300,000 
184011,530.000  51)4,900,000'  10,000  3,400,000 
1841 1 1,375,000  45:-!,9(M>,000  decreas.  decrease 
1842ll.674.iM)0  552.5011,000,  *97,000  *32,300,000 
1843 ;  1,788,000  5s9,900,000j  114,000  37,400,000 
1844:2,004,000  601,300,000  216,000  71,400,000 
1845 12,174,000  717,400,000!  170,000  5(5,100,000 
1846  j  2,207,000-748,000,000 1  93,000  30,600,000 
1847 12,576,000  850,000,000,:  309,000  102,000,000 
1848  2,800,000;918,000,000!  224,000!  68,000,000 

*  Gain  after  deducting  what  1841  lost 
COURT  PLASTEE.  To  make  this, 
black  silk  is  strained  and  brushed  over 
ten  or  twelve  times  with  the  following 
preparation :  —  Dissolve  £  an  ounce  of 
balsam  of  benzoin  in  6  ounces  of  rectified 
spirits  of  wine ;  and  in  a  separate  vessel 
dissolve  1  ounce  of  isinglass  in  as  little 
water  as  may  be.  Strain  each  solution, 
mix  them,  and  let  the  mixture  rest,  so 
that  any  undissolved  parts  may  subside ; 
when  the  clear  liquid  is  cold  it  will  form 
a  jelly,  which  must  be  warmed  before  it 
is  applied  to  the  silk.  When  the  silk 
coated  with  it  is  quite  dry,  it  must  be 
finished  off  with  a  coat  of  a  solution  of  4 
ounces  of  Chian  turpentine  in  6  ounces 
of  tincture  of  benzoin,  to  prevent  its 
cracking. 

CEANE.  In  Mechanics,  a  machine  for 
raising  heavy  weights,  and  depositing 
them  at  some  distance  from  their  origi- 
nal place  ;  for  example,  raising  bales  from 
the  hold  of  a  ship,  and  depositing  them 
on  the  quay.  A  jib  or  transverse  beam, 
inclined  to  the  vertical  in  an  angle  of  40° 
or  50°,  is  constructed,  which,  by  means 
of  a  collar,  turns  on  a  vertical  arbor.  The 
upper  end  of  the  jib  carries  a  fixed  pulley, 
and  the  lower  end  a  cylinder,  which  is 
put  in  motion  by  a  wheel  and  pinion,  or 
cog  wheel,  or  merely  with  a  handle.  The 
weight  is  made  fast  to  a  rope  which  pas- 
ses over  the  pulley  and  is  wound  round 
the  cylinder.    On  turning  the  cylinder, 


the  weight  is  raised  as  far  as  necessary  j 
the  jib  is  then  turned  on  its  arbor  till  the 
weight  is  brought  immediately  over  the 
spot  where  it  is  to  be  deposited ;  when, 
by  withdrawing  the  moving  power,  it  is 
allowed  to  descend  by  its  own  gravity. 
Cranes  may  be  constructed  of  immense 

Eower.  They  are  generally  turned  by 
uman  force  ;  sometimes,  however,  by  a 
steam  engine. 

CEANK.  A  mechanical  contrivance 
for  changing  a  revolving  into  an  alternate 
motion.  An  iron  axis  is  bent  in  some 
part  of  its  length  out  of  its  rectilinear  di- 
rection. As  the  axis  turns,  the  bent  part 
describes  the  circumference  of  a  circle, 
and  gives  a  reciprocating  motion  to  a  pis- 
ton rod  attached  to  it. 

Crank.  In  Nautical  language,  a  ship 
is  said  to  be  crank,  when  by  the  form  of 
its  construction,  or  by  want  of  a  sufficient 
quantity  of  ballast  or  cargo,  or  by  being 
loaded  too  much  above,  it  is  incapable  ?p 
carrying  sail  without  being  exposed  to 
the  danger  of  oversetting. 

CEAPE.  A  species  of  gauze  made  of 
raw  silk  woven  without  crossing.  It  is 
stiffened  with  gum-water. 

CRAYONS.  Colored  cylinders  used 
for  drawing  upon  paper  ;  they  are  usually 
made  of  a  fine  pipe-clay,  colored  with 
metallic  pigments  or  carmine.  Crayons 
containing  plumbago  are  styled  solid  lead 
pencils. 

General  Lomet  proposes  the  following 
composition  for  red  crayons :  He  takes 
the  softest  hematite,  grinds  it  upon  a  por- 
phyry slab,  and  then  carefully  elutriates 
it.  He  makes  it  into  a  plastic  paste  with 
gum  arabic  and  a  little  white  soap,  which 
he  forms  by  moulding,  as  above,  through 
a  syringe,  and  drying,  into  crayons.  The 
proportions  of  the  ingredients  require  to 
be  carefully  studied. 

Crayons,  Lithographic  Various  form- 
ulas have  been  given  for  the  formation  of 
these  crayons.  One  of  these  prescribes, 
white  wax  4  parts ;  hard  tallow  soap, 
shellac,  of  each  2  parts ;  lamp  black  1 
part.  Another  is,  dried  tallow  soap  and 
white  wax,  each  6  parts;  lamp  black  1 
part.  This  mixture  being  fused  with  a 
gentle  heat,  is  to  be  cast  into  moulds  for 
forming  crayons  of  a  proper  size. 

CEEAM.  A  semifluid  yellowish  sub- 
stance which  collects  on  the  surface  of 
milk,  and  which  is  made  into  butter  by 
the  process  of  churning.  When  the  milk 
of  any  animal  is  allowed  to  stand  for  some 
time,  it  spontaneously  undergoes  certaiD 
changes ;  this  substance  rises  to  the  sur- 
face and  forms  a  thin  stratum,  which  is 


112 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[CRO 


called  cream,  and  which  consists  chiefly 
of  oily  particles ;  while  the  milk  below, 
which  of  course  is  thinner  than  it  was 
before  the  cream  separated  from  it,  is  of 
a  pale,  blueish  color,  and  consists  of  curd, 
coagulum,  or  the  matter  of  which  cheese 
is  made.  When  cream  is  kept  for  some 
days  it  gradually  becomes  thicker,  and 

fmrtially  coagulated ;  and  if  put  into  a 
inen  bag,  and  suspended  from  the  ceil- 
ing of  a  cool  room,  it  will  acquire  the 
consistence  of  cheese ;  and  this  is  one 
among  other  modes  of  making  cream 
cheeses.  When  cream  is  shaken  by 
churning,  it  is  resolved  into  its  compo- 
nent parts,  and  hence  we  have  butter  and 
buttermilk.  In  order  to  make  butter  it 
is  not  always  necessary  that  the  cream 
should  be  separated  from  the  milk  ;  but 
whether  separated  or  not,  the  process  is 
facilitated  by  allowing  the  liquid  to  stand 
for  some  time,  during  which  a  part  of  the 
sugar  contained  in  the  serum  is  changed 
into  an  acid,  which  shortens  the  process 
of  churning  by  facilitating  the  separation 
of  the  butter  from  the  milk.  When 
either  cream  or  milk  is  churned  without 
having  previously  become  sour,  the  pro- 
cess is  much  more  tedious;  and  some- 
times, from  causes  not  easily  accounted 
for  by  the  dairy-maid,  it  is  unsuccessful, 
and  the  milk  is  said  to  be  bewitched.  The 
true  cause,  however,  is  the  want  of  acid- 
ity ;  because  it  has  been  found  that  the 
addition  of  a  small  portion  of  vinegar  will 
dissolve  the  charm,  and  cause  the  almost 
immediate  appearance  of  butter.  Cream, 
when  separated  from  milk,  and  kept  till 
it  has  become  acid,  is  frequently  mixed 
with  milk  newly  drawn  from  the  cow ; 
and  this  eaten  with  sugar  is  one  of  the 
most  delicious  preparations  of  the  dairy. 
Common  clotted  cream  is  simply  milk  and 
cream  in  a  coagulated  state,  and  sour. 
When  the  clotted  cream  is  broken  and  stir- 
red, and  the  whey  drawn  off,  the  mass  may 
be  turned  into  cheese  by  artificial  pressure, 
by  whioh  the  whey  is  separated  instan- 
taneously ;  or  by  suspending  it  in  a  po- 
rous bag,  in  a  cool  airy  situation,  when  it 
will  be  separated  by  degrees. 

CEEOSOTE  or  KREASOTE.  A  color- 
less, transparent,  oily  liquid,  separable 
from  wood-tar  and  pyroligneous  acid,  by 
repeated  distillation  and  rectification  ;  it 
appears  to  be  the  principle  to  which  the 
antiseptic  power  or  wood-tar,  smoke,  and 
crude  pyroligneous  acid  is  owing. 

Creosote  dissolves  several  salts,  particu- 
larly the  acetates,  and  the  chlorides  of 
calcium  and  tin ;  it  reduces  nitrate  and 
acetate  of  silver.    It  also  dissolves  indigo 


blue  ;  a  remarkable  circumstance.  Its 
action  upon  animal  matters  is  very  inter- 
esting. It  coagulates  albumen,  and  pre- 
vents the  putrefaction  of  butchers'  meat 
and  fish.  For  this  purpose  these  sub- 
stances must  be  steeped  a  quarter  of  an 
hour  in  a  weak  watery  solution  of  creo- 
sote, then  drained  and  hung  up  in  the 
air  to  dry.  Hence  Riechenbach  has  in- 
ferred that  it  is  owing  to  the  presence  of 
creosote  that  meat  is  cured  by  smoking ; 
but  he  is  not  correct  in  ascribing  the 
effect  to  the  mere  coagulation  of  the  albu- 
men, since  jibrine  alone,  without  creosote, 
will  putrefy  in  the  course  of  24  hours, 
during  the  heat  oi    summer.     It  kills 

Slants  and  small  animals.  It  preserves 
our  paste  unchanged  for  a  long  time. 

Creosote  exists  in  the  tar  of  beech- 
wood,  to  the  amount  of  from  20  to  25  per 
cent.,  and  in  crude  pyroligneous  acid,  to 
that  of  H. 

It  ought  to  be  kept  in  well-stoppered 
bottles,  because  when  left  open  it  becomes 
progressively  yellow,  brown,  and  thick. 

CROTON  AQUEDUCT.  This  beauti- 
ful structure  has  been  built  after  the  plan 
of  the  Eoman  buildings — that  is,  in  chan- 
nels of  masonry,  rather  than  in  metal 
pipes.  The  following  account  is  abridged 
from  Tower's  work  on  the  Crotpn  Aque- 
duct: 

Dr.  Brown,  in  1798,  first  called  attention 
to  the  necessity  of  a  good  supply  of  wa- 
ter for  the  city  of  New-York.  In  the 
next  year  the  Manhattan  Company  sank 
wells  of  great  depth.  In  1834,  an  act 
passed  the  Legislature,  authorizing  five 
Water  Commissioners  to  examine  and 
consider  ail  matters  relative  to  a  supply 
of  water  to  the  city.  These  Commission- 
ers decided  in  favor  of  using  the  Croton 
River,  and  bringing  it  in  a  closed  aque- 
duct of  masonry,  at  an  estimate  of 
$5,412,336  72.  The  work  was  commenced 
in  May,  1837,  and  the  22d  June,  1842,  the 
aqueduct  received  the  water  from  the 
fountain  reservoir  on  the  Croton ;  on  the 
27th  it  entered  the  receiving  reservoir  in 
the  city,  and  on  4th  July  it  was  admitted 
into  tne  distributing  reservoir.  The 
sources  of  the  Croton  River  are  in  Put- 
nam county,  50  miles  from  New-York ; 
they  are  about  twenty  lakes  or  ponds,  oc- 
cupying about  3,800  acres.  The  water  is 
so  remarkably  clear  and  pure,  that  the 
native  Indians  called  it  clear  water.  The 
dam  on  the  Croton  River  is  thirty-eight 
feet  above  the  original  level  of  the  water- 
flow,  and  sets  the  water  back  about  six 
miles,  forming  the  fountain  reservoir, 
which  contains  an  area  of  400  acres.  This 


CRU] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


113 


large  reservoir  allows  the  water  to  settle 
before  entering  the  aqueduct,  and  it  has 
an  available  capacity  of  600,000,000  gal- 
lons ;  this  has  been  looked  on  as  sufficient 
store  for  one-third  of  a  million  of  people 
for  ninety  days,  a  longer  period  than 
any  drought  would  last.  The  minimum 
flow  of  water  in  the  river  where  the  aque- 
duct begins,  is  27,000,000  gallons  in 
twenty-four  hours.  The  aqueduct  itself 
is  calculated  to  convey  60,000,000  gallons 
in  that  time.  From  the  fountain  reser- 
voir to  the  receiving  reservoir  is  thirty- 
eight  miles,  the  aqueduct  for  which  is  of 
stone,  except  where  the  Haarlem  Kiver 
is  crossed  over,  and  in  passing  a  deep 
valley  in  the  island,  where  iron  pipes  are 
used.  These  pipes  descend  and  rise 
again,  so  that  they  are  always  full.  The 
surface  of  the  reservoir  is  166£  feet  above 
the  level  of  the  tide  at  New-York  ;  that 
of  the  receiving  reservoir  is  119  feet,  so 
that  the  fall  of  the  river  during  its  course 
through  the  38  miles  of  aqueduct,  is  47  & 
feet.  From  the  receiving  reservoir  it  is 
carried  in  iron  pipes  (two  miles)  to  the 
distributing  reservoir,  where  the  surface 
of  the  water  is  115  feet  above  the  tide 
level. 

At  suitable  places  on  the  line  of  aque- 
duct six  waste  weirs  are  constructed,  to 
discharge  surplus  water  in  such  a  mode, 
that  when  the  water  reaches  a  certain 
level,  it  flows  off  at  the  side. 

For  ventilation,  hollow  cylinders  of 
stone  are  erected  over  the  aqueduct,  and 
rise  14  feet  above  the  surface  of  the 
ground.  These  occur  at  every  mile,  and 
at  every  third  mile  there  is  one  having  a 
door  to  allow  of  entrance  into  the  aque- 
duct ;  these  have  a  diameter  of  four  feet, 
the  former  only  of  two ;  the  top  is  cov- 
ered by  an  iron  grating.  Besides  these 
there  are  places  marked  at  every  quarter 
of  a  mile  of  the  course,  where  opening 
can  be  made  readily  in  cases  of  emergency. 
Where  streams  intersect  the  line  of  aque- 
duct, culverts  are  built  to  allow  them  to 
pass  under.  At  each  end  of  the  aqueduct 
are  gate  chambers,  with  two  sets  ot  gates, 
the  regulating  and  the  guard  gates  :  the 
former  of  gun  metal,  the  latter  of  cast  iron. 

The  height  of  the  interior  of  the  aque- 
duct is  8  feet  5?  inches,  and  the  greatest 
width  7  feet  .5  inches.  The  velocity  of 
the  water  is  lft  miles  per  hour  when  the 
water  is  two  feet  deep.  The  average 
depth  is  probably  four  feet. 

The  foundations  of  the  channel  were 
formed  with  cement,  the  side  walls  of 
stone,  and  the  bottom  and  inside  faced 
with  brick ;  the  top  also  covered  with  an 


arch  of  brick.     In  tunnel-cutting,  the  na- 
tural rock  in  some  places  served  as  roof. 

The  bridge  which  crosses  the  Haarlem 
River  is  the  most  interesting  work  on  the 
line  ;  its  width  is  21  feet,  and  it  is  150 
feet  from  the  top  of  the  work  to  the 
foundations  in  the  river.  The  iron  pipe 
conveying  the  water  along  this  is  3  feet 
in  diameter.  In  passing  through  the 
Manhattan  valley  two  pipes  are  used, 
each  3  feet  in  diameter ;  provision,  how- 
ever, has  been  made  for  four  such. 

The  capacity  of  the  receiving  reservoir 
is  150,000,000  gallons  when  full.  It  is 
divided  into  two  unequal  parts,  with  a 
connecting  pipe  to  sJIow  of  an  equalizing 
of  the  level.  The  distributing  reservoir 
is  two  miles  lower  down  the  island,  and 
three  miles  from  City  Hall ;  the  water  in 
it  is  36  feet  deep,  and  it  is  calculated  to 
hold  20,000,000  gallons.  It  is  40£  miles 
distant  from  the  fountain  reservoir. 

The  whole  of  the  cost  of  the  work,  ex- 
clusive of  the  pipes  in  the  city  below  the 
distributing  reservoir,  is  about  $9,000,000. 
It  is  a  beautiful  work  of  art, — a  worthy 
rival  of  the  finest  of  the  Roman  aque- 
ducts. The  success  of  this  undertaking 
in  New- York  has  stimulated  other  Atlan- 
tic cities  to  supply  themselves  Avith 
abundance  of  pure  water  in  a  similar 
manner  and  the  aqueduct  which  sup- 
plies Boston  from  the  Cochituate  pond 
is  highly  creditable. 

CRUCIBLES  are  small  conical  vessels, 
narrower  at  the  bottom  than  the  mouth, 
for  reducing  ores  in  docimacy  by  the  dry 
analysis,  for  fusing  mixtures  of  earthy 
and  other  substances,  for  melting  metals, 
and  compounding  metallic  alloys.  They 
ought  to  be  refractory  in  the  strongest 
heats,  not  readily  acted  upon  by  the  sub- 
stances ignited  in  them,  not  porous  to  li- 
quids, and  capable  of  bearing  considera- 
ble alternations  of  temperature  without 
cracking  ;  on  which  account  they  should 
not  be  made  too  thick.  The  best  cruci- 
bles are  formed  from  a  pure  fire-clay, 
mixed  with  finely  ground  cement  of  old 
crucibles,  and  a  portion  of  black  lead  or 
graphite.  Some  pounded  coke  may  be 
mixed  with  the  plumbago.  The  '  clay 
should  be  prepared  in  a  similar  way  as 
for  making  pottery-ware  ;  the  vessels  af- 
ter being  formed  must  be  slowly  dried 
and  then  properly  baked  in  the  kiln. 
Crucibles  formed  of  a  mixture  of  8  parts 
in  bulk  of  Stourbridge  clay  and  cement, 
5  of  coke,  and  4  of  graphite,  have  been 
found  to  stand  23  meltings  of  76  pounds 
of  iron  each,  in  the  RoyarBerlin  foundry. 
Such  crucibles  resisted  the  greatest  possi- 


114 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[cup 


ble  heat  that  could  be  produced,  in  which 
even  wrought  iron  was  melted,  equal  to 
150°  or  155°  Wedgewood,  and  bore  sud- 
den cooling  without  cracking.  Another 
composition  for  brass-founding  crucibles 
is  the  following :  i  Stourbridge  clay, 
$  burned  clay  cement,  I  coke  powder,  | 
pipe  clay.    The  pasty  mass  must  be  com- 

{>ressed  in  moulds.  The  Hessian  cruci- 
>les  of  Germany  are  made  from  a  fire- 
clay which  contains  a  little  iron,  but  no 
lime;  it  is  incorporated  with  silicious 
sand.  The  dough  is  compressed  in  a 
mould,  dried,  and  strongly  kilned.    They 


stand  saline  and  leaden  fluxes  in  docimas- 
tic  operations  very  well ;  are  rather  po- 
rous on  account  of  the  coarseness  of  the 
sand,  but  are  thereby  less  apt  to  crack 
from  sudden  heating  or  eoohng.  They 
melt  under  the  fusing  point  of  bar  iron. 
Beaufay  in  Paris  has  lately  succeeded  in 
making  a  tolerable  imitation  oi  the  Hes- 
sian crucibles  with  a  fire-clay  found  near 
Namur  in  the  Ardennes. 

Berthier  has  published  the  following 
elaborate  analysis  of  several  kinds  of  cru- 
cibles : 


St.  Etienne 

Hessian. 

Beaufay. 

English  for 

for 

Glass  Pots 

Bohemian 

Glass  Pots 

Oast  Steel. 

Cast  Steel. 

at  Nemours. 

Glass  Pots. 

of  Creusot. 

Silica,  -    -    -    - 

70-9 

64-6 

63-7 

65-2 

67-4: 

6S-0 

68-0 

Alumina,  -    -    - 

24-8 

34-4 

20-7 

25-0 

32-0 

29-0 

28-0 

Oxide  of  Iron,  - 

3-8 

1-0 

4-0 

7-2 

0-8 

2-2 

2-0 

Magnesia,      -    - 

trace 

— 

— 

trace 

trace 

0-5 

trace 

Water,      -    -    - 

— 

— 

10-3 

— 

— 

— 

1-0 

Wurzer  states  the  composition  of  the 
sand  and  clay  in  the  Hessian  crucibles  as 
follows : 

Clay — silica  10*1,  alumina  65-4,  oxides 
of  iron  and  manganese  1*2,  lime  0-3, 
water  23. 

Sand — silica  95*6,  alumina  2*1,  oxides 
of  iron  and  manganese  1*5,  lime  0-8. 

Black  lead  crucibles  arc  made  of  two 
parts  of  graphite  and  one  of  fire-clay, 
mixed  with  water  into  a  paste,  pressed  in 
moulds,  and  well  dried,  but  not  baked 
hard  in  the  kiln.  They  bear  a  higher  heat 
than  the  Hessian  crucibles,  as  well  as 
sudden  changes  of  temperature,  have  a 
smooth  surface,  and  are,  therefore,  pre- 
ferred by  the  melters  of  gold  and  silver. 
This  compound  forms  excellent  small  or 
portable  furnaces. 

CUDBEAR,  OR  PEESIO,  is  a  powder 
of  a  violet  red  color,  difficult  to  moisten 
with  water,  and  of  a  peculiar  but  not  dis- 
agreeable odor.  It  is  partially  soluble  in 
boiling  water,  becomes  red  with  acids, 
and  violet  blue  with  alkalies.  It  is  pre- 
pared in  the  same  way  as  archil,  only  to- 
wards the  end  the  substance  is  dried  in 
the  air,  and  is  then  ground  to  a  fine  pow- 
der, taking  care  to  avoid  decomposition, 
which  renders  it  glutinous.  In  Scotland 
they  use  the  lichen  tartareus,  more  rarely 
the  lichen  calcareus,  and  omphalodes, 
most  of  which  lichens  are  imported  from 
Sweden  and  Norway,  under  the  name  of 
rock  moss.  The  lichen  is  suffered  to  fer- 
ment for  a  month,  and  is  then  stirred 
about  to  allow  any  stones  which  may  be 
present  to  fall  to  the  bottom.    The  red 


mass  is  next  poured  into  a  flat  vessel,  and 
left  to  evaporate  till  its  urinous  smell  has 
disappeared,  and  till  it  has  assumed  an 
agreeable  color  verging  upon  violet.  It 
is  then  ground  to  fine  powder.  During 
the  fermentation  of  the  lichen,  it  is  wa- 
tered with  stale  urine,  or  with  an  equiva- 
lent ammoniacal  liquor  of  any  kind,  as  in 
making  archil. 

CUPELLATION  is  a  mode  of  analyz- 
ing gold,  silver,  palladium,  copper,  and 
platinum,  by  adding  to  small  portions  of 
alloys,  containing  these  metals,  a  bit  of 
lead,  fusing  the  mixture  in  a  little  cup  of 
bone  earth  called  a  cupel,  then  by  the 
joint  action  of  heat  and  air,  oxidizing 
the  copper,  tin,  &c,  present  in  the  pre- 
cious metals.  The  oxides  thus  produced 
are  dissolved  and  carried  down  into  the 
porous  cupel  in  a  liquid  state,  by  the  vi- 
trified oxide  of  lead.  (See  Assay,  Gold, 
and  Silver.) 

CURRYING  is  the  art  of  dressing 
cow-hides,  calf-skins,  seal-skins,  &c, 
principally  for  shoes  :  and  this  is  done 
either  upon  the  flesh  or  the  grain.  In 
dressing  leather  for  shoes  upon  the  flesh, 
the  first  operation  is  to  soak  the  leather 
in  water  until  it  is  quite  wetted,  then  the 
flesh  side  is  shaved  on  a  beam  about 
seven  or  eight  inches  broad,  with  a  knife 
of  peculiar  construction,  to  a  proper  sub- 
stance, according  to  the  custom  of  the 
country  and  the  uses  to  which  it  is  des- 
tined. This  is  one  of  the  most  curious 
and  laborious  steps  of  the  whole  process. 
The  knife  used  is  of  a  rectangular  form, 
with  two  handles,  one  at  each  end,  and  a 


cut] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


115 


double  edge.  It  is  thrown  into  water 
again,  and  scoured  on  a  board  or  stone 
commonly  set  apart  for  that  use.  Scour- 
ing is  done  by  rubbing  the  grain  or  hair 
side  with  pumice-stone,  or  with  some 
other  stone  of  a  good  grit.  These  stones 
force  out  of  the  leather  a  white  substance 
called  the  bloom,  produced  by  the  oak 
bark  in  tanning.  The  hide  or  skin  is 
then  conveyed  to  the  shade  or  drying- 
place,  where  the  oily  substances  are  ap- 
plied termed  stuffing,  or  dubbing ;  when 
it  is  thoroughly  dry,  an  instrument,  with 
teeth  on  the  under  side,  called  a  grain ing- 
board,  is  first  applied  to  the  fresh  side, 
which  is  called  graining, — then  to  the 
grain  side,  called  bruising.  The  whole 
of  this  operation  is  to  soften  the  leather 
to  which  it  is  applied.  Whitening  or 
paring  succeeds,  which  is  performed  with 
a  fine  edge  to  the  knife  already  described, 
ana  used  in  taking  off  the  grease  from 
the  flesh.  It  is  then  boarded  up  or 
grained  again,  by  applying  the  graining- 
board  first  to  the  grain,  and  then  to  the 
flesh.  It  is  then  fit  for  waxing,  which  is 
now  performed  by  coloring,  which  is  done 
by  rubbing  with  a  brush,  dipped  in  a 
composition  of  oil  and  lamp-black,  on  the 
flesh,  until  it  be  thoroughly  black.  It  is 
then  sized,  called  black-sizing,  with  a 
brush  or  sponge,  dried  and  tallowed ; 
and  when  dry,  this  sort  of  leather  called 
waxed,  or  black  on  the  flesh,  is  curried. 
The  currying  leather  on  the  hair  or  grain 
side,  called  blade,  on  the  grain,  is  the 
same  as  currying  on  the  flesh  until  we 
come  to  the  operation  of  scouring  it. 
Then  the  first  black  is  applied  to  it  while 
wet,  which  black  is  a  solution  of  sul- 
phate of  iron  or  copperas,  in  plain  wa- 
ter, or  in  the  water  m  which  the  skins 
as  they  come  from  the  tanner  have  been 
soaked.  This  is  first  put  upon  the  grain 
after  it  has  been  rubbed  with  a  stone ; 
then  rubbed  over  with  a  brush  dipped 
in  stale  urine  :  the  skin  is  then  stufted, 
and  when  dry,  it  is  seasoned — that  is, 
rubbed  over  with  a  brush,  dipped  in  cop- 
peras water,  on  the  grain  till  it  is  per- 
fectly black.  After  this,  the  grain  is 
raised  with  a  fine  graining-board :  when 
it  is  thoroughly  dry  it  is  whitened, 
bruised  again,  and  grained  in  two  or 
three  different  ways,  and  when  oiled 
upon  the  grain  with  a  mixture  of  oil  and 
tallow  it  is  finished. 
CURRY  POWDER.  {See  Turmeric.) 
CUTLERY,  in  the  general  sense,  com- 
prises all  edged  tmls ;  but  it  is  now  more 
particularly  confined  to  the  manufacture 
of  knives  and  forks,  scissors,  pen-knives, 


razors,  and  swords.  Those  articles  which 
do  not  require  a  fine  polish,  are  made 
from  blistered  steel;  while  those  which 
require  the  edge  to  possess  great  tenacity 
at  the  same  time  that  hardness  is  not  re- 
quired, are  made  from  shear  steel.  The 
finer  kinds  of  cutlery  are  made  from 
steel  which  has  been  in  a  state  of  fusion, 
termed  cast  steel;  no  other  kind  being 
susceptible  of  a  high  polish — {see  Steel.) 
It  can  then  be  made  so  as  to  be  welded 
to  iron  with  great  ease.  Table-knives 
are  mostly  made  of  shear  steel.  The 
blade  is  first  rudely  formed  and  cut  off. 
It  is  next  welded  to  a  rod  of  iron  about 
half  an  inch  square,  so  as  to  leave  as 
little  of  the  iron  part  of  the  blade  ex- 
posed as  possible :  of  the  iron  attached 
to  the  blade  enough  is  then  taken  off 
from  the  rod  to  form  the  bolster  or 
shoulder  and  the  tang.  To  give  the  bol- 
ster size,  shape,  and  neatness,  it  is  intro- 
duced into  a  die  and  a  swage  placed 
upon  it :  the  swage  has  a  few  small  dIows 
given  to  it  by  the  striker.  The  die  and 
swage  are  called  prints.  The  blade  is 
now  heated,  and  the  proper  anvil  finish 
is  given  to  it :  this  is  termed  smithing. 
It  is  again  heated  red-hot,  and  plunged 
down  into  cold  water.  It  thus  becomes 
hardened  and  requires  to  be  tempered 
down  to  a  blue  color,  when  it  is  ready 
for  the  grinder. 

Forks  are  a  different  branch,  of  manu- 
facture ;  they  are  made  of  small  rods  of 
steel,  drawn  out  flat  at  one  end  to  about 
the  length  of  the  prongs.  The  shank 
and  tang  are  heated,  and  the  form  given 
by  a  die  and  swage.  The  prongs  are 
then  formed  at  one  blow  by  a  stamp, 
which  weighs  about  100  lbs.,  and  falls 
from  a  height  of  7  or  8  feet  upon  the 
heated  end  of  the  rod:  a  fly-press  re- 
moves the  metal  left  between  the  prongs. 
The  forks  are  then  annealed,  which  sof- 
tens and  prepares  them  for  filing.  The 
inside  is  then  filed  ;  they  are  then  bent 
into  form  and  hardened,  by  heating  and 
plunging  them  into  cold  water.  The 
tempering  is  done  by  exposure  to  the 
degree  of  heat  at  which  grease  inflames. 

Almost  all  razors  are  made  of  cast  steel, 
the  quality  of  which  should  be  very  good, 
the  razor's  edge  requiring  great  hardness 
and  tenacity.  The  tempering  is  usually 
performed  by  placing  them  on  the  open 
fire,  in  a  sand  bath,  or  an  oil  bath,  or  a 
bath  of  fusible  metal  of  8  parts  of  bis- 
muth, 5  parts  of  lead,  and  3  of  tin  heated 
up  to  500°  Fahr.  Razors  are  ground 
crosswise,  upon  stones  from  4  to  7  inches 
in  diameter ;  a  small  stone  being  needful 


116 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[CYA 


to  make  the  sides  concave :  they  are  then 
smoothed  and  polished. 

Pen-knives  have  three  stages  in  their 
manufacture  :  1st,  the  forging  of  the 
blades,  the  spring,  and  iron  scales ;  the 
2d,  the  grinding  and  polishing  of  the 
blades:  and  3d,  the  handling,  or  fitting 
up  of  all  the  parts. 

The  finest  hind  of  cast  steel  is  used  in 
the  manufacture  of  ladies'  scissors  ;  the 
larger  scissors  have  a  blade  of  iron,  with 
steel  edge. 

The  various  processes  of  grinding  and 
polishing  are  performed  by  machinery, 
moving  in  general  by  the  power  of  steam, 
or  a  water-wheel.  The  grinding  and 
polishing  of,  cutlery  is  the  most  ruinous 
occupation  to  health  and  life  at  which 
any  man  can  be  occupied :  few  who  com- 
mence to  work  at  it  early  in  life,  reach 
forty  years  of  age. 

The  manufacture  of  handles  is  carried 
on  often  in  the  same  establishment  with 
the  steel  work.  According  to  the  tech- 
nical phraseology  applied,  all  handles  are 
called  hafts  in  which  a  tang  of  the  knife 
passes  into  a  hole  in  the  handle,  and  is 
there  fixed ;  while  the  handles  which  are 
formed  of  two  flat  pieces  riveted  to  a 
central  plate,  as  in  pen-knives,  are  called 
scales. 

The  workmen  who  engage  in  this  em- 
ployment confine  themselves  each  pretty 
nearly  to  one  kind  of  material.  The 
pearl-handle  makers  procure  the  shells 
from  the  shores  of  India  and  Africa; 
these  shells  are  about  six  inches  in  dia- 
meter, and  are  so  extremely  hard  that 
they  have  to  be  wetted  while  being  cut 
with  a  saw,  to  prevent  the  saw  from  be- 
ing softened  by  the  heat.  This  is  a 
dirty  occupation,  and  is  accompanied  by 
a  "  very  ancient  and  fish-like  smell," 
elicited  by  the  heat  from  the  shell  itself. 
The  pearl,  or  rather  mother-of-pearl,  is 
cut  up  into  thin  slices,  to  be  afterwards 
used  tor  the  scales  for  pen-knives,  razors, 
&c.  Ivory  handles  are  made  by  sawing 
up  elephants'  tusks  into  the  most  useful 
pieces  they  can  make,  by  means  of  a  cir- 
cular saw.  If  the  ivory  is  for  scales,  it  is 
cut  into  veneers ;  but  if  for  hafts,  it  is 
cut  into  small  oblong  pieces,  which  are 
afterwards  brought  to  shape  by  hand, 
polished,  and  pierced  for  the  reception 
of  the  tang.  Bone  handles  are  similarly 
made  by  cutting  with  a  small  circular 
saw,  and  then  filing  into  shape  ;  and  the 
same  may  be  said  of  ebony  and  fancy 
wood  handles  generally.  Saw-handles 
are  cut  out  of  wood,  which,  after  being 
planed  to  the  proper  thickness,  is  fixed 


in  a  vice,  cut  with  a  very  fine  saw, 
smoothed  with  files  and  glass-paper, 
pierced  with  rivet-holes,  and  riveted  to 
the  saws.  Metal  handles  are  of  course 
made  in  a  way  similar  to  other  articles  of 
metal. 

Horn  handles  have  a  peculiarity  in 
their  mode  of  manufacture,  which  places 
them  in  a  distinct  rank.  When  horn  is 
made  hot,  it  becomes  so  soft  and  ductile 
that  it  may  be  pressed  into  moulds  ;  and 
this  circumstance  is  taken  advantage  of 
to  give  an  ornamental  device  to  horn 
handles,  except  stages  horn,  which  is  left 
in  its  natural  state.  The  tips  or  solid 
parts  of  the  ox-horn  and  buffalo-horn 
are  made  into  hafts,  while  the  other  parts 
are  made  into  scales.  The  mould  for 
pressing  is  in  two  halves,  which  close 
together  like  a  pair  of  pincers ;  and  this 
mould  has  the  device  on  each  of  its 
halves.  The  mould  is  heated  in  a  fire ; 
the  piece  of  horn  is  cut  nearly  to  the  re- 
quisite size,  and  put  into  it ;  and  the 
mould  is  pressed  in  a  powerful  vice, 
whereby  the  horn  receives  the  impress 
of  the  device. 

There  is  also  a  good  deal  of  skill  shown 
in  staining  horn,  bone,  and  ivory,  or  in 
bleaching  them ;  as  also  in  studding  and 
ornamenting  them  in  various  ways. 

CYANIDE  OF  POTASSIUM.  This 
salt,  so  much  used  now  in  the  electrotype 
processes,  is  prepared,  according  to  Lie- 
big's  formula,  oy  mixing  8  parts  of 
Sounded  prussiate  of  potash,  sharply 
ried,  with  3  parts  of  pure  carbonate  of 
potash,  fusing  the  mixture  in  an  iron 
crucible,  by  a  moderate  red  heat,  and 
keeping  it  so,  till  the  glass  or  iron  rod 
with  which  the  fluid  mass  should  be  oc- 
casionally stirred,  comes  out  covered 
with  a  white  crust.  The  crucible  is  then 
to  be  removed  from  the  fire;  and  after 
the  disengaged  iron  has  fallen  to  the  bot- 
tom, the  supernatant  fluid,  still  obscure- 
ly red  hot,  is  to  be  poured  off  upon  a 
clean  surface  of  iron  or  platinum.  After 
concretion  and  cooling,  the  white  saline 
mass  is  to  be  pounded  while  hot,  and 
then  kept  in  a  well-stopped  bottle.  It 
consists  of  about  5  parts  of  cyanide  of 
potassium,  and  1  of  cyanate  of  potash. 
For  most  purposes,  and  the  analysis  of 
ores,  the  latter  ingredient  is  in  no  ways 
detrimental. 

CYANITE.  A  massive  and  crystal- 
lized mineral.  It  has  a  pearly  lustre,  is 
translucent,  and  of  various  shades  of 
blue :  it  is  a  silicate  of  alumina,  with  a 
trace  of  oxide  of  iron.  Only  found  in  pri- 
mitive rocks. 


dag] 


CYCLOPEDIA    OP    TUB    USEFUL    ARTS, 


117 


CYANOGEN.  An  essential  ingredient 
of  Prussian  blue.  Cyanogen  is  a  gas  of 
a  strong  and  peculiar  odor,  resembling 
that  of  rubbed  peach  leaves ;  it  is  ob- 
tained by  heating  cyanuret  of  mercury. 
Under  a  pressure  of  between  three  and 
four  atmospheres  it  becomes  a  limpid 
liquid.  It  extinguishes  a  taper,  is  high- 
ly poisonous  and  unrespirable,  and  burns 
in  contact  of  air  with  a  rich  purple  flame. 
Water  absorbs  between  4  and  5  times  its 
volume  of  the  gas.  It  is  composed  of 
carbon  and  nitrogen  in  the  proportions 
of  12  carbon+14  nitrogen=26  cyanogen; 
it  is  therefore  a  bicarburet  of  nitrogen. 
Mixed  with  oxygen  it  explodes  by  the 
electric  spark,  and  is  resolved  into  car- 
bonic acid  and  nitrogen  gas.  It  com- 
bines with  hydrogen  to  produce  the  hy- 
drocyanic or  prussic  acid  :  it  forms  with 
the  metals  cyanurets  or  cyanides. 

CYANOMETER.  An  instrument  con- 
trived by  Saussure  for  determining  the 
cteepness  of  the  tint  of  the  atmosphere. 
A  circular  band  of  thick  paper  or  paste- 
board is  divided  into  51  parts,  each  of 
which  is  painted  with  a  different  shade 
of  blue,  decreasing  gradually  from  the 
deepest  blue  formed  by  a  mixture  of 
black,  to  the  lightest  formed  by  a  mix- 
ture of  white.  The  colored  zone  is  held 
in  the  hand  of  the  observer,  who  notices 
the  particular  tint  which  corresponds  to 
the  color  of  the  sky.  The  number  of 
this  tint,  reckoned  from  the  lightest 
shade,  marks  the  intensity  at  the  time 
of  observation. 

DAGUERREOTYPE.  The  art  of  im- 
pressing distinct  and  permanent  images 
on  polished  metallic  surfaces.  It  received 
its  name  from  M.  Daguerre,  who  disco- 
vered the  mode  in  1839,  and  from  whom 
the  French  government  bought  the  right 
to  the  discovery  by  giving  him  an  annu- 
ity of  10,000  francs.  Compared  with  the 
present  processes  his  views  were  very 
meagre  and  incomplete.  The  views  taken 
were  of  landscapes,  and  the  process  in 
his  hands  consisted  in  coating  the  silver 
plate  with  iodine  to  a  gold  color,  expos- 
ing in  the  camera  for  ten  minutes  in  full 
sunlight,  then  exposing  the  plate  to  the 
fumes  of  mercury,  and  washing  in  hypo- 
sulphate  of  soda.  Dr.  Draper  (now  of 
New  York)  made  the  plate  more  sensi- 
tive by  exposing  it  to  chlorine  gas  after 
it  had  received  the  iodine  coating.  Views 
could  thus  be  taken  in  shade,  and  in  a 
shorter  time  ;  the  impression  also  was 
more  distinct.  Chloride  of  iodine  was 
soon  after  substituted  for  chlorine  and  io- 
dine separately ;  and,  still  later,  bromide 


of  iodine  was  tried  with  much  gi eater 
success. 

At  the  present  time  the  art  is  practised 
with  wonderful  delicacy  of  manipulation, 
and  perfection  in  result,  in  this  country. 
It  is  acknowledged  that  American  da- 
guerreotypes excel  European  in  beauty  of 
finish,  with  mellowness  and  depth  of 
tint.  Those  taken  in  France  are  much 
better  than  English  ones,  which  i3  no 
doubt  due  to  the  clearer  and  less  cloudy 
skies  of  France.  Perhaps  it  may  be  the 
same  reason  which  causes  to  be  produced 
better  portraits  in  America  than  in  west- 
ern Europe. 

The  plate  which  receives  the  image  is 
copper  coated  with  silver,  either  by  the 
ordinary  process  of  plating,  or  by  the 
electrotype  method :  the  latter  is  prefer- 
able. The  first  step  in  the  process  is  the 
cleansing  the  plate.  Too  much  atk  ntion 
cannot  be  devoted  to  this,  as  upon  it  de- 
pends subsequent  success.  It  is  impos- 
sible to  take  a  picture  on  a  dirty  plate. 
The  slightest  trace  of  oxide,  sulphuret, 
or  even  film  of  air  adhering  to  the  plate, 
is  sufficient  to  prevent  the  appearance  of 
an  image.  Various  plans  of  cleaning 
plates  are  practised.  Some  use  rotten 
stone  and  water,  made  acid  by  nitric 
acid ;  others  use  alcohol  and  ammonia 
water.  These  are  rubbed  on  to  the  plate 
with  small  pieces  of  Canton  flannel.  The 
rotten  stone  should  be  very  fine,  and  the 
acid  very  dilute,  else  the  plate  will  be 
streaked.  It  should  be  cleaned  in  the 
centre  first,  and  then  the  edges  wiped 
off.  The  acid  may  be.  removed  from  the 
plate,  by  washing  with  alcohol,  or  weak 
solution  of  potass  ;  washing  with  a  solu- 
tion of  hydriodate  of  potass  increases  the 
sensitiveness.  After  being  cleaned  the 
plates  are  Imffed,  or  rubbed  with  a  pad 
covered  with'  cotton,  velvet,  or  buckskin 
leather.  Great  delicacy  is  employed  in 
the  application  of  the  buff,  which  should 
remove  all  traces  of  the  materials  used 
for  polishing,  and  give  the  final  purity  to 
the  plate.  The  plate  is  now  ready  to  re- 
ceive the  coating,  or  films  of  iodine  and 
bromine.  Small  boxes  hold  the  ingre- 
dients in  a  glass  saucer  at  the  bottom, 
and  the  plates  are  placed  on  the  sliding 
frame  above,  and  passed  over  the  surface 
of  the  saucers  until  they  receive  the  due 
quantity  of  these  ingredients.  This  quan- 
tity varies  with  the  nature  of  the  light  and 
desired  appearance  of  the  picture.  The 
depth  of  the  coating  is  known  by  the  co- 
lor of  the  plate,  which  is  first  straw  yel- 
low, then  orange,  then  rose  color,  violet, 
steel  blue,   indigo,   and  green.     If  the 


118 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[> 


coating  be  continued  beyond  this,  it 
passes  into  yellow  again,  and^  through  the 
same  range  of  colors.  The  iodine  in  the 
box  should  be  quite  dry,  as  the  slightest 
damp  on  the  plate  mars  the  coating. 
The  Dromine  is  used  as  bromide  of  lime, 
made  by  mixing  bromine  with  fresh 
slaked  lime,  till  the  whole  is  of  an  orange 
tint.  As  a  rule,  a  good  picture  will  be 
produced  by  coating  with  iodine  to  a 
dark  orange  yellow,  then  with  the  bro- 
mide of  lime  coat  to  a  deep  rose  red,  coat 
again  with  iodine  one-tenth  as  long  as  at 
first  coating.  The  plate  now  coated  is 
very  sensitive,  the  least  exposure  to  light 
decomposing  its  surface.  Hence  it  ir  ne- 
cessary to  shut  the  plate  up  in  the  tablet 
immediately :  this  is  a  close  case  with  a 
a  sliding  lid.  It  is  introduced  into  the 
camera,  and  the  lid  raised  when  we  wish 
it  to  receive  an  image.  The  selection  of 
a  good  camera  is  a  tine  qua  nan  with  the 
daguerreotype  artist.  Generally  those  of 
Voigtlander  of  Germany  have  the  best 
lenses,  and  are  to  be  preferred.  Daguer- 
reotypists,  however,  in  this  country  pre- 
fer the  American  cameras.  For  taking 
views,  the  camera  invented  by  Mr.  Har- 
rison is  by  far  the  best  yet  made  for  such 
purposes.  It  has  been  found  advanta- 
geous to  blacken  the  inside  of  the  came- 
ra, which  absorbs  the  rays  falling  on  the 
sides,  and  thus  prevents  their  reflection 
and  interference  Avith  the  rays  falling 
upon  the  plate.  A  room  lighted  from 
above  is  more  suitable  than  a  window  or 
side  light,  the  latter  producing  the  sha- 
dows too  deeply  marked.  A  northern 
aspect  is  preferred,  as  the  light  is  more 
uniform  through  the  day,  although 
light  from  the  south  has  a  greater  chemi- 
cal influence.  The  sitter  should^  not  be 
placed  too  near  the  window,  nor  in  front 
of  it.  The  thus  of  exposure  in  the  came- 
ra varies  with  the  light,  amount  of  coat- 
ing, and  time  of  the  day,  from  10  se- 
conds to  1*  minutes.  The  operator's 
judgment  is  the  best  guide.  The  plate 
is  now  removed  from  the  camera  in  the 
closed  tablet,  and  has  to  be  exposed  to 
the  vapor  of  mercury,  in  order  to  bring 
out  the  image,  for  as  yet  no  trace  of  any 
delineation  is  visible.  The  mercury 
bath  is  an  iron  vessel  of  an  inverted 
conical  form,  the  mercury  occupying  the 
lower  part ;  is  heated  with  a  spirit  lamp 
until  it  reaches  the  temperature  of  90 
centigrade,  when  the  plate  is  now  placed 
on  the  frame  attached  to  the  upper  part 
of  the  bath,  where  it  receives  the  vapor 
of  the  quicksilver.  A  little  window  at 
the  side  allows  the  operator  to  observe 


the  advancement  of  the   process.    The 
I  image  gradually  is  developed  as  the  mer- 
|  curial  vapor  coats  the  plate,  and  when 
j  the    greatest    distinctness    is    produced 
(which  is  generally  after  two  minutes), 
the  plate  is  removed.     As  far  as  the 
image  is  concerned,  nothing  more  is  ne- 
cessary to  be  done. 

The  picture  is  made,  and  has  now  to 
be  preserved.  It  is  necessary  first  to  re- 
move the  superfluous  iodine  and  bro- 
mine from  the  sides  of  the  picture,  where 
the  light  has  not  produced  any  chemical 
action  ;  this  is  accomplished  by  washing 
with  hyposulphate  of  soda,  a  salt  which 
is  capable  of  dissolving  the  iodide  of  sil- 
ver formed  on  the  plate.  The  washing 
should  be  performed  immediately  after 
the  exposure  to  the  mercury.  The  plate 
is  held  by  a  pliers  in  the  hand,  and  the 
hyposulphate  solution  is  poured  over 
the  plate,  and  washed  around  it.  The 
plate  is  then  rinsed  with  water,  and  dried 
off  by  the  heat  of  a  spirit  lamp  applied 
underneath.  The  hyposulphate  solution 
should  be  weak. 
The  picture  is  now  formed,  and  the  su- 

Eerfluous  coating  removed  :  it  has  yet  to 
<sfi,ced.  This  is  accomplished  by  gild- 
ing, or  applying  a  weak  solution  of  chlo- 
ride of  gold,  washed  over  the  plate.  This 
protects  it  from  any  further  action  of  light, 
rendering  the  image  permament.  The 
solution  of  the  chloride  of  gold  is  poured 
on  the  plate,  heated  beneath  by  the  lamp, 
and  allowed  to  remain  on  as  long  as  any 
small  bubbles  continue  to  appear. 

The  pictures  are  usually  colored  by 
means  of  mineral  powders,  laid  on  dry 
with  a  brush.  Yellow  ochre  burned  is 
the  usual  flesh  color,  mixed  with  carmine 
or  chrome  yellow.  Oxide  of  bismuth 
forms  the  white ;  Prussian  blue,  the 
blue ;  and  the  green  is  formed  by  the 
mixture  of  blue  and  yellow. 

AVhen  the  silver  plate  is  coated,  an  io- 
dide of  silver  is  produced.  When  it  is 
further  exposed  to  bromine,  a  portion  of 
bromide  of  silver  is  also  formed,  so  that 
the  plate  is  then  covered  with  two  pre- 
parations of  silver,  the  bromide  and  the 
iodide  ;  the  latter  is  the  salt  which  it  is 
desirable  to  have  formed  upon  the  plate, 
and  all  applications  have  for  their  object 
the  ready  formation  and  decomposition 
of  it.  When  exposed  to  the  light  the  io- 
dide of  silver  is  decomposed  in  some 
places,  while  in  other  places  the  decom- 
position is  not  effected.  When  the  plate 
already  acted  on  by  light  is  exposed  to 
the  mercury,  the  latter  coats  these  places 
where  the  light  has  acted  on  so  that  the 


dag] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


119 


light  parts  of  the  picture  are  an  amalgam 
of  mercury  while  the  dark  places  are  of 
silver ;  the  intermediate  tints  are  a  mix- 
ture of  the  two.  The  daguerreotype  as 
at  present  produced  shows  only  the  ef- 
fect of  lights  and  shade.  It  has  not  yet 
satisfactorily  produced  color.  Occasion- 
ally indeed,  in  the  hands  of  an  artist,  a 
single  color  is  produced,  and  Becquerel, 
by  the  aid  of  a  galvanic  current  travers- 
ing the  plate  while  in  the  camera,  has 
produced  an  occasional  color  (not  the  na- 
tural one).  Mr.  Hill,  of  Greene  Co. 
N.  Y.,  has  been  asserted  to  have  pro- 
duced the  colors  of  nature,  and  plates  so 
colored  have  been  seen  by  a  few;  but 
whether  from  uncertainty  in  the  use 
of  the  materials,  or  want  of  artistic  finish 
in  the  plates  so  produced,  the  publication 
has  not  yet  appeared.  It  may  not  be 
amiss  to  point  out  the  road  to  success — 
it  lies  in  the  taking  images  more  rapidly  ; 
more  sensitive  plates,  and  more  powerful 
accelerators  must  be  used.  It  is  very 
probable  that  a  polished  surface  is  not 
that  which  is  capable  of  receiving  the  co- 
lors ;  a  surface  chemically  pure,  yet  not 
capable  of  reflection,  will  be  likely  to  an- 
swer better;  hence  the  newly  electro- 
typed  surface  should  be  most  effective, 
and  when  this  is  excited  by  more  sensi- 
tive coatings  than  the  present,  it  is  likely 
that  the  colors  of  nature  will  be  reflected 
as  they  impinge.  There  is  no  doubt  that 
the  coating  with  mercury  covers  these 
up,  hence  this  must  ultimately  be  dis- 
pensed with,  as  also  the  use  of  cloride  of 
gold.  Chloro-cromic  acid  is  a  powerful 
accelerator,  and  may  be  useful  in  the 
first  stages  ;  but  the  whole  difficulty  has 
not  as  yet  been  solved. 

Daguerreotype  plates  may  be  etched  and 
thus  the  art  usefully  applied  to  objects  of 
natural  history.  To  do  this  it  is  neces- 
sary to  etch  away  the  dark  parts  and 
leave  the  white  untouched.  The  plate  is 
immersed  in  a  fluid  consisting  of  dilute 
nitric  acid,  nitrous  acid,  chloride  of  sodi- 
um, and  nitrate  of  potass.  These  two 
salts  are  decomposed  when  the  fluid  is 
heated  and  chlorine  and  nitrous  acids  are 
evolved,  these  attack  and  remove  the 
silver  or  dark  parts,  but  have  no  effect  on 
the  mercury,  so  that  the  lights  of  the  pic- 
ture form  the  etching  ground,  and  pro- 
tect these  portions  of  the  plate.  Am- 
monia is  used  to  wash  the  plate  and  re- 
move the  cloride  of  silver  formed,  and 
allow  the  etching  being  carried  on  far- 
ther. The  plate  is  now  inked  and  allowed 
to  dry,  the  surface  is  then  polished,  and 
gilded  by  the   electrotype,  those   parts 


only  taking  the  gold  which   had  been 

Eolished  previously.  The  plate  may  now 
e  still  further  etched  with  nitric  acid ; 
the  ink  having  been  washed  out  by  pot- 
ash and  the  etching  carried  on  until  it 
has  gone  sufficiently  deep.  M.  Claudet 
has  obtained  some  beautiful  engravings 
of  the  lower  animals  by  this  process. 

Daguerreotye  images  and  photographic 
impressions  may  be  reproduced  in  the 
following  manner : 

The  image  is  received  in  the  camera 
obscura  on  a  plate  of  silver,  strongly 
iodized  ;  the  plate  is  then  exposed  to  the 
vapour  of  mercury,  but  not  to  the  action 
of  hyposulphite'  of  soda.  It  is  then 
plunged  into  a  solution  of  sulphate  of  cop- 
per, placing  it  for  a  few  instants  in  com- 
munication with  the  negative  pole  of  a 
battery  and  closing  the  circuit  with  a  pla- 
tina  wire.  The  copper  deposits  itself 
only  on  the  parts  covered  by  the  mercury, 
the'iodide  of  silver  not  being  a  conduc- 
tor of  electricity.  The  plate  is  then 
washed  with  distilled  water,  then  with 
the  hyposulphite  of  soda  to  remove  the 
iodide,  and  quickly  dried  ovp.r  a  spirit 
lamp.  The  image,  in  which  the  copper 
represents  the  light  parts  and  the  silver 
dark,  is  transferred,  at  least  the  copper, 
on  very  thin  plates  of  gelatine.  An  in- 
verted image  is  thus  obtained,  since  the 
copper  which  is  opaque,  represents  the 
light  parts.  The  transfer  is  made  by  run- 
ning on  the  plate  a  clear  solution  of  gela- 
tine, and  allowing  it  to  dry  ;  after  which 
the  gelatinous  foil  on  which  the  copper 
adheres,  is  attached.  The  negative  proof 
obtained,  the  next  part  of  the  process  is, 
to  re-produce  a  positive  image ;  for  this 
purpose  a  sheet  of  photographic  paper  is 
taken,  on  which  is  carefully  applied  the 
proof  in  gelatine  the  face  on  which  is  the 
copper  underneath.  The  whole  is  then 
exposed  to  diffused  light  during  a  quar- 
ter of  an  hour ;  the  paper  is  then  plunged 
into  water  in  order  to  be  washed,  and 
then  into  a  solution  of  hyposulphite  of 
soda  to  remove  the  salt  of  silver ;  it  is 
then  washed  in  a  large  quantity  of  water 
and  driedj,  by  this  a  perfect  and  positive 
reproduction  of  a  daguerreotype  image  is 
obtained.  If  it  be  desired  to  obtain  the 
reproduction  of  a  drawing  or  an  engrav- 
ing, a  negative  proof  is  taken  on  a  pre- 
pared iodized  plate,  in  placing  it  over  the 
design  or  engraving  and  exposing  the 
whole  to  the  light.  It  is  then  passed 
through  the  mercurial  process  and  the 
series  of  operations  above  described. 

The  following  improvement  in  the  pro- 
cess of  Daguerreotyping  has  just  been 


120 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[dam 


discovered  by  Niepce,  the  first  discove- 
rer of  the  art.  Trie  engraving  is  to  be 
submitted  to  vapor  of  iodine  (at  a  tempe- 
rature of  15  or  2(>  degrees)  during  about 
ten  minutes  ;  a  longer  time  is  necessary 
if  the  temperature  be  less  elevated ;  ten 
grammes  of  iodine  to  be  used  per  square 
of  4  inches.  The  paper  intended  to  re- 
ceive the  impression  is  to  be  covered 
with  a  coat  of  paste,  taking  care  previ- 
ously to  have  it  moistened  with  water 
containing  one  degree  of  pure  sulphuric 
acid.  The  proofs,  after  being  pressed 
with  a  linen  cloth,  present  a  design  of 
admirable  purity.  These  impressions, 
taken  on  paste  will,  however,  in  drying, 
become  vaporous ;  but  if  taken  on  paper 
prepared  with  one  or  two  layers  of  starch, 
the  design  will  not  only  be  clear,  but  will 
preserve  much  better.  What  is  most 
extraordinary  is,  that  many  impressions 
may  be  taken  from  the  same  print  with- 
out submitting  it  to  a  new  preparation — 
the  last  proofs  being  always  the  clearest. 
Designs  of  various  colors  may  thus  be 
obtained  according  as  the  paste  is  more 
or  less  boiled,  or  according  to  the  quanti- 
ty of  acid  used.  Proofs  may  also  be  taken 
on  different  metals  by  observing  the  fol- 
lowing precaution.  In  submitting  the 
engraving  to  the  vapor  of  iodine,  care 
should  be  taken  to  have  it  perfectly  dry, 
in  order  that  the  white  portions  of  it  may 
become  impregnated.  In  this  case  it 
should  be  exposed  but  a  few  minutes  to 
the  vapor.  Let  it  be  afterwards  applied, 
without  wetting  it,  to  a  plate  of  silver, 
and  then  placed  under  a  press ;  at  the  end 
of  five  or  six  minutes  there  will  be  a  most 
faithful  reproduction  of  the  original.  By 
afterwards  exposing  the  plate  to  the  va- 
por of  mercury,  a  proof  similar  to  that  of 
a  daguerreotype  is  obtained. 

It  h.as  been  rumored,  that  at  a  meeting 
of  the  French  Academy  of  Sciences,  M. 
Niepce  had  declared  iiis  capability  of 
taking  the  pictures  in  the  natural  colors  ; 
his  process  has  not  yet  reached  this 
countrv. 

DAliLINE,  the  same  as  Inuline,  the 
fecula  obtained  from  elecampane,  and 
analogous  in  many  respect  to  starch.  It 
is  not  employed  in  the  arts. 

DAIRY.  An  apartment  in  a  house,  or 
a  separate  building,  for  the  purpose  of 
holding  milk  and  "manufacturing  it  into 
butter,  cheese,  or  other  dairy  produce. 
On  a  small  scale,  where  butter  only  is 
made  from  milk,  the  dairy  may  be  a  room 
in  the  north  side  of  the  dwelling  house ; 
or  it  may  form  one  of  the  offices  connect- 
ed with  the  kitchen  court.    The  requi- 


sites for  the  room  to  contain  the  milk 
are — an  equal  temperature  throughout, 
the  year,  viz :  between  48°  and  55°  ;  .suf- 
ficient ventilation  to  carry  off  all  bad 
smells  and  impurities  in  the  air;  and  the 
exclusion  of  flies  and  other  insects.  An 
equable  temperature  is  maintained  by 
thick  or  by  hollow  walls,  and  by  double 
windows.  In  winter  the  temperature  is 
somewhat  raised  by  the  warm  milk,  and  in 
summer  it  is  cooled  to  the  degree  required 
by  ventilation  and  the  evaporation  of 
water  poured  on  the  floor.  The  ventilation 
is  effected  by  opening  the  glazed  sashes  of 
the  windows,  and  supplying  their  places 
by  wire  shutters,  and  indeed  one  of  the 
best  modes  of  arranging  the  windows  of 
a  dairy  is  to  have  wooden  shutters  out- 
side for  closing  in  the  most  severe  weather 
in  winter ;  next,  a  fixed  frame  of  wire- 
work  to  exclude  the  flies ;  and  within 
this,  at  three  or  four  inches  distance,  the 
glazed  sash,  which  should  be  made  to 
open.  A  dairy  on  a  large  scale  is  most 
conveniently  arranged  as  a  detached 
building;  in  which  case,  it  contains  a 
milk-room,  a  churning-room,  and  a  dairy 
scullery,  or  place  for  scalding  the  utensils. 
If  cheese  is  to  be  made,  a  room  will  be 
required  for  a  cheese  press  and  another 
for  drying  the  cheeses. 

DAMASCUS  BLADES,  are  swords  or 
cimeters,  presenting  upon  the  surface  a 
variegated  appearance  of  watering,  as 
white,  silvery,  or  black  veins,  in  fine 
lines,  or  fillets ;  fibrous,  crossed,  inter- 
laced, or  parallel,  &c.  They  are  brought 
from  the  East,  being  fabricated  chiefly  at 
Damascus,  whence  their  name.  Their 
excellent  quality  has  become  proverbial ; 
for  which  reason  these  blades  are  much 
sought  after  by  military  men,  and  are 
high  priced.  The  oriental  processes  have 
never  been  satisfactorily  described;  but 
of  late  years  methods  have  been  devised 
in  Europe  to  imitate  the  fabric  very 
well. 

Clouet  and  Hachette  pointed  out  the 
three  following  processes  for  producing 
Damascus  blades:  1,  that  of  parallel  fil- 
lets;  2,  that  by  torsion;  3,  the  mosaic. 
The  first,  which  is  still  pursued  by  some 
French  cutlers,  consists  in  scooping  out 
with  a  graving  tool  the  faces  of  a  piece  of 
stuff  composed  of  thin  plates  of  different 
kinds  of  steel.  These  hollows  are  by  a 
subsequent  operation  filled  up,  and 
brought  to  a  level  with  the  external  faces, 
upon  which  they  subsequently  form  tress- 
like figures.  2.  The  method  of  torsion 
which  is  more  generally  employed  at 
present,  consists  of  forming  a  bundle  of 


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CYCLOPEDIC    OF    THE    USEUL    ARTS. 


121 


rods  or  slips  of  steel,  which  are  welded 
together  into  a  well-wrought  bar,  twisted 
several  times  round  its  axis.  It  is  re- 
peatedly forged,  and  twisted  alternately ; 
after  which  it  is  slit  in  the  line  of  its  axis, 
and  the  two  halves  are  welded  with  their 
outsides  in  contact ;  by  which  means  their 
faces  will  exhibit  very  various  configura- 
tions. 8.  The  mosaic  method  consists  in 
preparing  a  bar,  as  by  the  torsion  plan, 
and  cutting  this  bar  into  short  pieces  of 
nearly  equal  length,  with  which  a  fagot 
is  formed  and  welded  together;  taking 
eare  to  preserve  the  sections  of  each  piece 
at  the  surface  of  the  blade.  In  this  way, 
all  the  variety  of  the  design  is  displayed, 
corresponding  to  each  fragment  of  the  cut 
bar. 

The  blades  of  Clouet,  independently  of 
their  excellent  quality,  their  flexibility, 
and  extreme  elasticity,  have  this  advant- 
age over  the  oriental  blades,  that  they 
exhibit  in  the  very  substance  of  the  metal, 
designs,  letters,  inscriptions,  and,  gener- 
ally speaking,  all  kinds  of  figures  which 
had  been  delineated  beforehand. 

Notwithstanding  these  successful  re- 
sults of  Clouet,  it  was  pretty  clear  that 
the  watered  designs  of  the  true  Damas- 
cus cimeter  were  essentially  different. 
M.  Breant  has  at  last  completely  solved 
this  problem.  He  has  demonstrated  that 
the  substance  of  the  oriental  blades  is  a 
cast-steel  more  highly  charged  with  car- 
bon than  our  European  steels,  and  in 
which  by  means  of  a  cooling  suitably  con- 
ducted, a  crystallization  takes  place  of  two 
distinct  combinations  of  carbon  and  iron. 
This  separation  is  the  essential  condition; 
for  if  the  melted  steel  be  suddenly  cooled 
in  a  small  crucible  or  ingot,  there  is  no 
damascene  appearance. 

DAMASKEENING.  The  art  of  inlay- 
ing iron  and  steel  with  gold  and  silver, 
originally  practised  at  Damascus  in  Syria. 

DAMASSIN.  A  species  of  woven 
damask  with  gold  and  silver  flowers. 

DAMPEE.  An  iron  plate  sliding  back- 
wards and  fowards  in  a  groove,  and  so 
arranged  as  to  enlarge  or  contract  and 
occasionally  close  the  chimneys  of  fur- 
naces, steam  boilers,  &c,  so  as  to  in- 
crease or  diminish  the  draught  of  air 
through  the  fire,  and  consequently  regu- 
late the  intensity  of  the  combustion. 

DAMPS.  The  noxious  exhalations  of 
mines  and  excavations.  The  carbu- 
retted  hydrogen  of  coal  mines  is  called 
Fire  Damp  ;  carbonic  acid  is  termed  Choke 
Damp. 

D  ATHOL1TE  or  DATOLITE.  A  mine- 
ral compound  of  lime,  silica,  and  boracic 


acid,  a  boro  silicate  of  lime.  It  becomes 
:  opaqe  when  heated. 

DAVIT.  A  piece  of  timbei  used  in 
I  managing  the  anchor. 

DAVITE.  Fibrous  sulphate  of  alumi- 
na, found  near  Bogota  in  Columbia. 

DEAD  BEAT.  In  clock-work  (called 
also  dead  scapement,  or  scapement  of  re- 
pose), a  peculiar  kind  of  scapement  in- 
vented by  Mr.  George  Graham  about  the 
year  1700,  with  a  view  to  lessen  the 
effect  of  the  wheel-work  on  the  motion 
of  the  pendulum ;  and  acquired  its  name 
from  the  circumstance  that  the  seconds' 
index  stands  still  after  each  drop,  whereas 
the  index  of  a  clock  with  a  recoiling 
scapement  is  always  in  motion,  hobbling 
backward  and  forward. 

DEAD  LIGHTS.  Strong  wooden  prists 
or  shutters,  put  over  the  glass-windows 
of  the  cabin  in  bad  weather,  as  a  defence 
against  the  sea. 

DEAD  BECKONING.  A  term  used 
in  navigation  to  express  the  estimation 
that  is  made  of  a  ship's  place  without 
having  recourse  to  observation  of  the  ce- 
lestial bodies.  It  is  made  by  observing 
the  way  she  makes  by  the  log,  and  the 
course  on  which  she  lias  been  steered, 
making  allowance  for  drift,  leeway,  &c. 

DECANTATION.  The  pouring  off  a 
clear  liquid  from  its  subsidence  or  resi- 
due ;  it  is  often  resorted  to  in  the  chemi- 
cal laboratory  instead  of  filtration,  the 
clear  supernatant  liquor  being  poured  or 
syphoned  off  from  precipitates,  which 
may  thus  be  repeatedly  washed  or  edul- 
corated, so  as  to  free  them  from  all  solu- 
ble matters. 

DECAEBONIZATION  OF  CAST 
IBON.  This  process  is  resorted  to  in 
order  to  convert  cast  iron  into  steel,  or 
by  a  further  decarbonization  to  reduce  it 
to  the  state  of  malleable  iron  •  hence, 
many  articles  which  were  formerly  exclu- 
sively manufactured  of  wrought  iron  are 
now  cast,  and  afterwards  decarbonized — 
such  as  horseshoes,  &c. ;  and  in  other 
cases  various  cutting  instruments  are 
cast,  and  afterwards  brought  to  a  proper 
hardness  by  a  similar  process.  The  arti- 
cles to  be  decarbonized  are  packed  in 
finely  powdered  haematite,  or  native  oxide 
of  iron,  and  exposed  for  a  sufficient  time 
to  a  high  red  heat.  It  is  often  necessary 
to  mix  iron  filings  or  turnings  with  hae- 
matite :  these  substances,  thus  applied, 
gradually  abstract  the  excess  of  carbon 
in  cast  iron,  and  reduce  it  to  a  state  ana- 
lagous  to  that  of  steel ;  or,  by  a  longer 
continuance  of  heat,  to  that  of  soft  iron. 
In   some    cases,   however,   the    process 


122 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[det 


seems  rather  to  affect  the  texture  and 
mechanical  properties  than  the  composi- 
tion of  the  iron,  and  is  therefore  more 
analogous  to  annealing. 

DECOMPOSITION,  is  the  separation 
of  the  constituent  principles  of  any  com- 
pound body.  The  following  table,  the 
result  of  important  researches  recently 
made  by  M.  Persoz,  professor  of  chemis- 
try at  Strasburgh,  shows  the  order  in 
which  decompositions  take  place  among 
the  successive  substances,  diminishing  in 
power  from  above  downwards. 


Nitric  Acid. 

Muriatic  Acid. 

Oxide   of  Magnesium 

Oxide  of  Magnesium 

—           Silver 

—           Cobalt 

—           Cobalt 

—          Nickel 

—           Nickel 

Protox  of  Mercury 

Protox.  of  Cerium 

—           Cerium 

Oxide   of  Zinc 

Oxide   of  Zinc 

Protox  of  Manganese 

Protox  of  Manganese 

Oxide    of  Lead 

—           Iron 

—           Cadmium 

—           Uranium 

—           Copper 

—           Copper 

—           Glucinum 

—           Tin 

—           Alumium 

Oxide  of  Glucium 

—           Uranium 

—           Alumium 

—           Chromium 

—           Uranium 

Protox  of  Mercury 

—           Chromium 

Oxide    of  Mercury 

—           Iron 

—           Iron 

—           Tin 

—           Bismuth 

—           Bismuth 

— 

—           Antimony 

The  study  of  the  tables  of  decomposi- 
tion are  of  the  utmost  importance  to  the 
practical  and  manufacturing  chemist,  as 
they  are  the  means  of  protecting  him 
from  much  waste  and  loss. 

DECREPITATION,  is  the  crackling 
noise,  attended  with  the  flying  asunder 
of  their  parts,  made  by  several  salts  and 
minerals,  when  heated.  It  is  caused  by 
the  unequal  sudden  expansion  of  then- 
substance  by  the  heat.  Sulphate  of  bary- 
ta, chloride  of  sodium,  calcareous  spar, 
nitrate  of  baryta,  and  many  more  bodies 
which  contain  no  water,  decrepitate  most 
violently,  separating  at  the  natural  joints 
of  their  crystalline  structure. 

DEFECATION.  The  freeing  from 
dregs  or  impurities. 

DEFLAGRATION.  The  sudden  blaz- 
ing up  of  a  combustible ;  as  of  charcoal 
or  sulphur  when  thrown  into  melted  nitre. 

DELPHIN1A.  The  vegeto-alkaliue 
principle  of  the  Delphinium  stapliysa- 
gria,  or  stavesacre.    It  is  poisonous. 

DELIQUESCENT,  is  said  of  a  solid 
which  attracts  so  much  moisture  from 
the  air  as  to  become  spontaneously  soft 
or  liquid;  such  as  potash  and  muriate 
of  lime. 

DEPILATORY,   is  the  name  of  any 


substance  capable  of  removing  hairs  from 
the  human  skin  without  injuring  its  tex- 
ture. They  act  either  mechanically  or 
chemically.  The  first  are  commonly  glu- 
tinous plasters  formed  of  pitch  and  resin, 
which  stick  so  closely  to  the  part  of  the 
skin  where  they  are  applied,  that  when 
removed,  they  tear  away  the  hairs  with 
them.  This  method  is  more  painful,  but 
less  dangerous  than  the  other,  which 
consists  in  the  solvent  action  of  a  men- 
struum, so  energetic  as  to  penetrate  the 
pores  of  the  skin,  and  destroy  the  bulb- 
ous roots  of  the  hairs.  This  is  com- 
posed either  of  caustic  alkalies,  sulphuret 
of  baryta,  or  arsenical  preparations.  Cer- 
tain vegetable  juices  have  also  been  re- 
commended for  the  same  purpose ;  as 
spurge  and  acacia.  The  bruised  eggs  of 
ants  nave  likewise  been  prescribed.  But 
the  oriental  rusma  yields  to  nothing  in 
depilatory  power.  Gadet  de  Gassincourt 
has  publish. ed  in  the  Dictionnaire  des 
Sciences  Medicales,  the  following  recipe 
for  preparing  it. 

Mix  two  ounces  of  quicklime  with  half 
an  ounce  of  orpiment  or  realgar,  (sulphu- 
ret of  arsenic ;  j  boil  that  mixture  in  one 
pound  of  strong  alkaline  ley,  then  try  its 
strength  by  digging  a  feather  into  it,  and 
when  the  flue  falls  off,  the  rusma  is  quite 
strong  enough.  It  is  applied  to  the  hu- 
man skin  by. a  momentary  friction,  fol- 
lowed by  washing  with  warm  water. 
Such  a  caustic  liquid  should  be  used  with 
the  greatest  circumspection,  beginning 
with  it  somewhat  diluted.  A  soap  is 
sometimes  made  with  lard  and  the  above 
ingredients;  or  soft  soap  is  combined 
with  them  ;  in  either  case  to  form  a  depi- 
latory pommade.  Occasionally  one  ounce 
of  orpiment  is  taken  to  eight  ounces  of 
quicklime,  or  two  to  twelve,  or  three  to 
fifteen ;  the  last  mixture  being  of  course 
the  most  active.  Its  causticity  may  be 
tempered  by  the  addition  of  one-eighth 
of  starch  or  rye  flour,  so  as  to  form  a  soft 
paste,  which  being  laid  upon  the  hairy 
spot  for  a  few  minutes,  usually  carries 
away  the  hairs  with  it. 

DESTRUCTIVE  DISTILLATION.  A 
term  applied  to  the  distillation  of  organic 
products  at  high  temperatures,  by  which 
the  ultimate  elements  are  separated  or 
evolved  in  new  combinations.  The  de- 
structive distillation  of  coal  is  resorted  to 
for  the  production  of  gas,  and  that  of 
bone  for  the  production  of  ammonia,  and 
of  wood  for  the  formation  of  vinegar. 

DETONATING  TUBE.  A  stout  glass 
tube,  used  in  the  chemical  laboratory  for 
the  detonation  of  gaseous  bodies.    It  is 


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CYCLOPEDIA    OF    TTIE    USEFUL    ARTS. 


123 


generally,  as  represented  in  the  annexed 
cut,  graduated  into  centesimal  parts,  and 
perforated  by  two  opposed  wires,  for  the 
purpose  of  passing  an  electric 
spark  through  the  gases  which 
are    introduced    into    it,    and 
which  are  confined  within   it 
over  water  or  mercury.     When 
a  detonating  tube  is  used  over 
eit  ler  of  these  fluids,  the  small- 
est possible  quantity  of  explo- 
sive gas  should  be  introduced 
(       into  it,  as  in  consequence  of 
/—A     the  expansion  which  ensues,  a 

portion  is  apt  to  be  forced  out 

at  the  moment  of  the  explosion.  The 
tube,  when  used,  should  be  firmly  held  : 
a  spring  is  sometimes  substituted  for  the 
grasp  of  the  hand,  but  it  is  inconvenient. 
DETONATING  POWDER.  A  term 
applied  in  chemistry*  to  fulminating  mer- 
cury and  silver,  and  to  other  compounds 
which  suddenly  explode  when  struck  or 
heated.  Some  of  these  compounds  have 
lately  been  much  used  for  the  ignition  of 
gunpowder  in  percussion  locks. 

DETONATION.  When  chemical  com- 
bination or  decomposition  is  sudden  and 
attended  by  flame  and  explosion,  it  is 
often  said  to  be  effected  by  detonation. 
If  a  mixture  of  hydrogen  gas  and  oxygen 
be  inflamed  by  the  electric  spark  or  by  a 
taper,  it  burns  rapidly  and  with  explo- 
sion, and  is  said  to  detonate.  When  a 
grain  or  two  of  phosphorus  is  mixed 
with  chlorate  of  potassa  and  struck  witli 
a  hammer,  the  mixture  detonates. 

DETRITUS.  A  geological  term  applied 
to  deposits  composed  of  various  sub- 
stances which  have  been  comminuted  by 
attrition.  The  larger  fragments  are  usu- 
ally termed  debris ;  those  which  are  pul- 
verized, as  it  were,  constitute  detritus. 
Sand  is  the  detritus  of  siliceous  rocks. 

D  E  U  T  0  X I D  E,  literally  means  the 
second  oxide ;  but  is  usually  employed 
to  denote  a  compound  containing  two 
atoms  or  two  prime  equivalents  of  oxy- 
gen to  one  or  more  of  a  metal.  Thus  we 
say  deutoxide  of  copper,  and  deutoxide 
of  mercury.  Berzefius  has  abbreviated 
this  expression  by  adopting  the  princi- 
ples of  the  French'  nomenclature  ot  1787 ; 
according  to  which  the  higher  stage  of 
oxydizement  is  characterized  by  the"  ter- 
mination ic,  and  the  lower  by  ous,  and  he 
writes  accordingly  cupric  and  mercuric, 
to  designate  the  deutoxides  of  these  two 
metals ;  cuprous  and  mercurous,  to  de- 
signate their  protoxides. 

DEXTRINE.  This  substance  has  ex- 
actly the  same  chemical  composition  as 


starch,  consisting  of  24  atoms  of  carbon, 
20  of  hydrogen,  and  10  of  oxygen  (Du- 
mas) ;  but  it  is  distinguished  from  starch 
by  its  solubility  in  cold  water,  like  gum, 
and  not  being  affected  by  iodine.  British 
gum,  as  it  is  called,  or  roasted  starch,  is 
merely  dextrine  somewhat  discolored  ;  a 
substance  apparently  used  for  the  paste 
on  the  queen's  head  British  letter- 
stamps.  A  process  discovered  by  M. 
Pay  en,  and  patented  in  France  by  M. 
Henze,  for  making  dextrine,  consists  in 
moistening  one  ton  of  dry  starch  with 
water  containing  4i  lbs.  of  strong  nitric 
acid.  The  starch  thus  uniformly  wetted, 
is  made  up  into  small  bricks  or  loaves, 
and  dried  in  a  stove.  It  is  then  rubbed 
down  into  a  coarse  powder,  and  exposed 
in  a  stove-room  to  a  stream  of  air  heated 
to  about  180°  F.  Being  now  triturated, 
sifted,  and  heated  in  a  stove  to  about 
228°  F.,  it  forms  a  perfect  dextrine  of  a 
fair  color ;  because  the  acid  acts  as  a 
substitute  for  the  higher  heat,  used  in 
making  the  British  gum.  Such  an  arti- 
cle makes  a  fine  dressing  for  muslin  and 
silk  goods,  and  is  much  employed  in 
French  surgery,  for  making  a  stiff  paste- 
support  to  the  bandages  of  fractured 
limbs. 

DIALS  are  instruments  known  to  and 
constructed  by  the  ancients,  for  the  mea- 
surement of  time. 

In  constructing  a  sun-dial,  the  object 
is  to  find,  by  means  of  his  shadow,  the 
sun's  distance  at  any  time  from  the  meri- 
dian. When  this  distance  is  known,  the 
hour  is  also  known,  provided  we  suppose 
the  sun's  apparent  motion  to  be  uniform, 
and  that  (Turing  the  whole  course  of  a 
day  he  moves  hi  a  circle  parallel  to  the 
equator.  Neither  of  these  conditions  is, 
in  fact,  accurately  fulfilled,  bnt  the  er- 
ror which  this  gives  rise  to  is  of  small 
amount;  and  it  is,  moreover,  sufficiently 
obvious  that  the  use  of  a  dial  is  not  to 
indicate  the  hour  with  astronomical  pre- 
cision, but  merely  to  give  such  an  ap- 
proximation as  is  necessary  for  the  pur- 
poses of  civil  life. 

Dials  are  usually  constructed  on  an 
immovable  surface,  and  admit  of  an  in- 
finite number  of  different  constructions, 
all  depending  on  the  nature  of  the  sur- 
face and  its  position  with  regard  to  the 
equator  of  the  earth.  The  general  prin- 
ciples, however,  are  the  same  in  all,  and 
depend  on  the  simplest  elements  of 
geometry  and  astronomy.  The  first  part 
that  claims  attention  is  the  style  or  gno- 
mon, or  axis  of  the  dial,  which  is  usually 
a  cylindrical  rod,  or  the  edge  of  a  thin 


124 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[dta 


plate  of  metal.  The  style  must  be  di- 
rected perpendicularly  to  the  terrestrial 
equator ;  in  which  direction  it  may  be 
considered,  on  account  of  the  smallness 
of  the  earth's  diameter  in  comparison  of 
the  distance  of  the  sun,  as  coinciding 
with  the  axis  of  the  diurnal  rotation ; 
consequently  the  plane  which  passes 
through  the  style  and  its  shadow  on  the 
surrounding  surfaces,  and  which  always 
passes  through  the  centre  of  the  sun, 
will  be  an  hour  plane,  and  turn  with  the 
sun  as  the  sun  turns  round  the  style  by 
the  effect  of  the  diurnal  motion.  All  that 
remains  to  be  done,  in  addition,  is  to  dis- 
cover, and  describe,  for  the  different 
hours  of  the  day,  the  intersections  of  this 
variable  hour  plane  with  the  surface  on 
which  the  dial  is  to  be  constructed.  On 
these  intersections  the  shadow  of  the 
style  will  be  projected  every  day  at  the 
same  hour ;  because  at  the  same  hour 
the  sun  must  have  returned  to  the  same 
hour  plane,  although  his  distance  from 
the  equator  may  be  different. 

From  these  considerations  it  is  mani- 
fest that  the  whole  theory  of  dialling  is 
comprehended  in  the  solution  of  this 
general  problem : — "  Twelve  planes  all 
intersecting  each  other  in  the  same 
straight  line,  and  making  with  each  other 
equal  angles  of  15°,  being  given  in  posi- 
tion; to  find  the  intersections  of  those 
planes  with  any  surface  whatever,  also 
given  in  form  and  position."  The  sur- 
face which  intersects  the  hour  planes 
may  be  of  any  kind  whatever,  but  for 
obvious  reasons  it  is  generally  a  plane  ; 
and  when  its  position  with  respect  to  the 
common  intersection  of  the  hour  planes 
(which  is  the  style  of  the  dial)  and  to  any 
one  of  those  planes  is  given,  the  traces 
or  intersections,  which  are  in  this  case 
all  straight  lines,  are  the  hour  lines  on 
the  dial,  and  easily  calculated  by  the 
ordinary  rules  of  trigonometry  or  geo- 
metry. 

According  to  the  position  of  the  dial 
with  respect  to  the  horizon  of  the  place, 
the  dial  is  horizontal,  vertical,  or  inclined. 
The  most  com- 
mon    construc- 
tion is  the  Hori- 
zontal  Dial,    or 
that     in    which 
the  plane  of  the 
dial    is    parallel 
to  the   horizon, 
and  consequent- 
ly  makes    with 
the  style  an  an- 
gle equal  to  the 


^jt> 

n 

'//\ 

V 

H 

\V 

IV 

x  xi  xn  i  u 

equo 
this  is  the  same  as  th»;  polar  dial ;  but 
at  all  other  places,  the  hour  lines  inter- 
sect each  other  in  the  point  in  which  the 
style  intersects  the  plane  of  the  dial, 
which  point  is  called  the  centre,  and  the 
angles  they  make  with  one  another,  or 
with  the  xii  hour  line,  depend  on  the 
latitude. 

After  the  horizontal  dials,  the  construc- 
tion most  frequently  employed  is  that  in 
which  the  plane  of  the  dial  is  vertical ; 
for  example,  when  fixed  on  the  wall  of  a 
house.  In  this  case,  the  positions  of  the 
different  hour  lines  depend  on  the  lati- 
tude of  the  place  and  on  the  aspect  ot  the 
dial ;  that  is  to  say,  its  position  with  re- 
spect to  the  meridian.  _  If  the  dial  is  per- 
pendicular to  the  meridian,  it  is  a  smith 
dial,  or  north  dial,  according  as  it  faces 
the  south  or  north.  (The  vertical  south 
dial  is  represented  in 
the  annexed  figure.) 
When  not  perpendi- 
cular to  the  meridian, 
the  vertical  dial  is  said 
to  be  declined.  The 
formula  for  the  hour 
lines  of  a  south  verti- 
cal dial  differs  from 
that  for  a  horizontal 
dial  in  no  respect  excepting  that  the  sine 
of  the  latitude  is  changed  into  the  co- 
sine, the  cause  of  which' will  be  obvious 
when  it  is  considered  that  the  plane  of 
the  dial  in  passing  from  the  horizontal 
to  the  south  vertical  direction  preserves 
its  inclination  to  the  different  hour 
planes  unaltered ;  while  the  angle  which 
it  makes  with  the  style,  or  the  axis  of  the 
earth,  is  the  complement  of  the  angle  it 
made  with  the  same  line  in  its  former 
position.  Let  y,  therefore,  be  the  hour 
angle  at  the  centre  of  the  dial ;  and  put- 
ting, as  before,  h  =  the  hour  from  noon, 
and  I  =  the  latitude,  the  formula  for  the 
south  vertical  dial  is  tan.  y  =  tan.  h  cos. 
I ;  whence  it  follows  that  a  horizontal 
dial  constructed  for  any  given  latitude 
will  be  a  south  vertical  dial  for  any  place 
of  which  the  latitude  is  the  complement 
of  the  latitude  of  the  former  place, — a 
property  which  was  discovered  by  the 
Arabians.  The  hour  lines  of  the  vertical 
north  dial  are  found  exactly  in  the  same 
way  as  those  of  the  south  dial. 

DIAMOND.  (A  corruption  of  ada- 
mant). The  most  valuable  of  the  pre- 
cious stones.  Diamonds  were  originally 
discovered  in  Bengal,  and  in  the  Island 
of  Borneo.  About  the  year  1720  they 
were  found  in  Brazil.    One  lately  found 


dia] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


125 


at  Bahia  was  worth  $225,000,  though 
sold  hy  the  negro  finder  for  $175.  #  They 
always  occur  in  a  detached  state  in  allu- 
vial soil.  The  primitive  crystalline  form 
of  the  diamond  is  a  regular  octahedron, 
of  which  there  are  numerous  modifica- 
tions. Diamonds  are  found  of  all  colors  : 
those  which  are  colorless,  or  which  have 
some  very  decided  tint,  are  most  es- 
teemed; the  latter,  however,  are  rare. 
Those  which  are  slightly  discolored  are 
the  least  valuable.  "The  diamond  is  the 
hardest  known  substance,  and  can  only 
be  polished  by  its  own  dust  or  powder. 
The  art  of  splitting  or  cutting  and  polish- 
ing this  gem,  though  probably  of  remote 
antiquity  in  Asia,  was  first  introduced 
into  Europe,  in  1486,  by  Louis  Berghem, 
of  Bruges,  who  accidentally  discovered 
that  by  rubbing  two  diamonds  together 
their  surfaces  might  be  abraded.  They 
are  cut  chiefly  into  two  forms,  rose  and. 
brilliant :  the  latter  have  the  finest  effect, 
but  require  a  sacrifice  of  a  larger  portion 
of  the  gem  ;  so  that  the  weight  ot  an  or- 
dinary polished  diamond  often  does  not 
exceed  half  that  of  the  rough  gem.  The 
largest  known  diamond  is  probably  that 
mentioned  by  Tavernier,  in  possession  of 
the  great  mogul ;  it  was  found  in  Gol- 
conda  in  1550;  is  of  the  size  of  half  a 
hen's  egg,  and  said  to  weiirh  900  carats. 

The  next  most  valuable  diamond  in 
the  world  has  lately  come  into  the  pos- 
session of  Queen  Victoria,  and  was 
exhibited  in  the  World's  Fair.  It  was 
brought  from  the  East  Indies,  and  pre- 
sented to  the  queen  by  the  East  India 
Company ;  it  is  called  the  "  Koh-i- 
Noor  "  (Mountain  of  Light).  All  the  na- 
tives of  Iliridostan  have  heard  of  it,  and 
it  has  had  a  mythological  lame  for  a 
number  of  centuries.  Its  possession  by 
any  prince  was  superstitiously  held  to  be 
the  type  of  dominion.  It  was  discovered 
in  the  famous  diamond  mines  of  Golcon- 
da,  but  when  is  unknown.  It  was  a 
state  jewel  of  the  Delhi  Emperors  until 
1739.  In  that  year  the  Persian  warrior, 
Nadir  Shah,  conquered  the  Delhi  mon- 
arch, and  carried  away  as  his  most  pre- 
cious trophy,  the  "  Koh-i-Noor."  It  af- 
terwards came  into  the  possession  of  the 
Meers  of  Affghan,  and  was  an  heir  loom 
in  the  family  of  Ahmed  Khan  Abdali, 
and  was  carried  to  Lahore  by  the  fugi- 
tive prince  Shah  Shooja,  from  whom  it 
was  extorted  by  the  basest  of  means — 
starvation.  This  was  the  hospitality  of 
the  Sikhs.  By  the  conquest  ol  the  Sikh 
territory,  in  1848,  this  diamond  came  in- 
to the  possession  of  Lord  Dalhousie,  ac- 


cording to  stipulation,  to  be  presented  to 
the  queen.  Its  value  is  about  eight  mil- 
lions of  dollars  ;  it  weighs  280  carats,  and 
is  of  the  finest  water.  It  never  has  been 
in  a  dealer's  hands,  but  has  descended, 
either  by  fraud  or  force,  from  one  prince 
to  another.  Its  shape  is  like  the  pointed 
Jialf  of  a  hen's  egg. 

Among  the  crown  jewels  of  Russia  is  a 
magnificent  diamond,  weighing  195  ca- 
rats :  it  is  of  the  size  of  a  pigeon's  egg, 
and  was  purloined  from  a  brahminical 
idol  by  a  French  soldier;  it  passed 
through  several  hands,  and  was  ultimately 
purchased  by  the  Empress  Catharine  for 
the  sum  of  90,0002.  and  an  annuity  of 
4,0002.  Perhaps  the  most  perfect  and 
beautiful  diamond  hitherto  found  is  a 
brilliant  brought  from  India  by  a  gentle- 
man of  the  name  of  Pitt,  who  sold  it  to 
the  recent  Duke  of  Orleans  for  the  sum 
of  100,0002.  It  weighs  about  136  carats, 
or  544  grains. 

That  the  diamond  is  combustible  wa3 
first  proved  by  the  Florentine  academi- 
cians in  16?4,"who  found  that  when  ex- 
posed to  the  heat  of  the  sun  concentrated 
in  the  focus  of  a  large  lens,  it  burned 
away  with  a  blue  lambent  flame.  The 
products  of  its  combustion  were  first 
examined  by  Lavoisier,  in  1772,  who 
showed  that  when  it  was  burned  in  air 
or  oxygen  it  produced  carbonic  acid; 
subsequent  experiments  have  shown 
that  nothing  but  carbonic  acid  is  thus 
formed  ;  and  hence  it  is  proved  that  the 
diamond  is  charcoal  or  carbon  in  a  pure 
and  crystalline  form. 

On  the  banks  of  the  river  Nik olaiefska, 
Tobolsk,  in  Siberia,  in  the  midst  of  the 
auriferous  sand  washings,  has  been  dis- 
covered a  mine  of  stones  resembling  dia- 
monds ;  they  are  a  little  less  heavy  and 
hard,  but  are  harder  than  granite.  It  is 
proposed  to  call  them  Diamantoid.  Dia- 
mond dust  is  used  for  working  cameos, 
polishing  brilliants,  and  sharpening  cut- 
lery. 

Diamonds  are  valued  by  multiplying 
the  square  of  their  weight  by  the  value 
of  each  carat.  Allowing  a  rough  diamond 
to  weigh  4  carats,  and  the  value  of  each 
carat  is  $8,  then  4X4=16X8=1128,  the 
value  of  a  rough  diamond.  Manufac- 
tured or  cut  diamonds,  have  their  values 
found  by  doubling  the  weight — for  ex- 
ample, a  cut  diamond  of  two  carats,  dou- 
ble the  2,  thus  4X4=16  ;  multiply  as  be- 
fore 16X8=128,  the  value  of  a  cut  dia- 
mond 2  carats  fine.  rT<v?\onds  are 
weighed  by  the  carat  of  3$  grains  Troy 
weight. 


126 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[< 


Diamonds,  cutting  of.  Although  the 
diamond  is  the  hardest  of  all  known 
substances,  yet  it  may  be  split  by  a  steel 
tool,  provided  a  blow  be  applied;  but 
this  requires  a  perfect  knowledge  of  the 
structure,  because  it  will  only"  yield  to 
such  means  in  certain  directions.  This 
circumstance  prevents  the  workman  from 
forming  facettes  or  planes  generally,  by 
the  process  of  splitting ;  he  is  therefore 
obliged  to  resort  to  the  process  of  abra- 
sion, which  is  technically  called  cutting. 
The  process  of  cutting  is  effected  by  fix- 
ing the  diamond  to  be  cut  on  the  end  of 
a  stick  or  handle,  in  a  small  ball  of  ce- 
ment, that  part  which  is  to  be  reduced 
being  left  to  project.  Another  diamond 
is  also  fixed  in  a  similar  manner ;  and  the 
two  stones  being  rubbed  against  each 
other  with  considerable  force,  they  are 
mutually  abraded,  flat  surfaces,  or  fa- 
cettes, being  thereby  produced.  Other 
facettes  are  formed  by  shifting  the  dia- 
monds into  fresh  positions  in  the  cement, 
and  when  a  sufficient  number  are  pro- 
duced, they  are  fit  for  polishing.  The 
stones,  when  cut,  are  fixed  for  this  pur- 
pose, by  imbedding  them  in  soft  solder, 
contained  in  a  small  copper  cup,  the 
part  or  facette,  to  be  polished,  being  left 
to  protrude. 

DIAMOND  MICROSCOPES  were  first 
suggested  by  Dr.  Goring,  and  have  been 
well  executed  by  Mr.  Pritchard.  Previ- 
ous to  grinding  a  diamond  into  a  spheri- 
cal figure,  it  should  be  ground  flat  and 
parallel  upon  both  sides,  that  by  looking 
through  it,  as  opticians  try  flint  glass,  we 
may  see  whether  it  has  a  double  or  triple 
refractive  power,  as  many  have,  which 
would  render  it  useless  as  a  lens.  Among 
the  fourteen  different  crystalline  forms  of 
the  diamond,  probably  the  octahedron 
and  the  cube  are  the  only  ones  that  will 
give  single  vision.  It  will,  in  many  cases, 
be  advisable  to  grind  diamond  lenses 
plano-convex,  both  because  this  figure 
gives  a  low  spherical  aberration,  and  be- 
cause it  saves  the  trouble  of  grinding  one 
side  of  the  gem.  A  concave  tool  of  cast 
iron,  paved  with  diamond-powder,  ham- 
mered into  it  by  a  hardened  steel  punch, 
was  employed  by  Mr.  Pritchard.  This 
ingenious  artist  succeeded  in  completing 
a  double  convex  of  equal  radii,  of  about 
one-twenty-fifth  of  an  inch  focus,  bear- 
ing an  aperture  of  one-thirtieth  of  an 
inch  with  distinctness  upon  opaque  ob- 
jects, and  its  entire  diameter  upon  trans- 
parent ones.  This  lens  gives  vision  with 
a  trifling  chromatic  aberration ;  in  other 
respects,  like  Dr.  Goring's  Amician  Re- 


flector, but  without  its  darkness  ;  its  light 
is  said  to  be  superior  to  that  of  any  com- 
pound microscope  whatever,  acting  with 
the  same  power  and  the  same  angle  of 
aperture.  The  advantage  of  seeing  an 
object  without  aberration  by  the  interpo- 
sition of  only  a  single  magnifier,  instead 
of  looking  at  a  picture  of  it  with  an  eye- 
glass, is  evident.  We  thus  have  a  simple 
direct  view,  whereby  we  shall  see  more 
accurately  and  minutely  the  real  texture 
of  objects. 

DIAPER.  A  woven  linen  ornamented 
with  patterns,  and  used  for  towels  and 
table-linen ;  it  sometimes  resembles  an 
inferior  kind  of  damask.  It  is  said  to 
hav«  been  originally  manufactured  at 
Ypres  in  Flanders :  whence  the  term 
d' Ypres,  corrupted  into  diaper. 

DIAPHANOUS.  A  term  applied  to 
bodies  which  permit  the  light  to  pass 
through  their  substances.  It  is  the  sy- 
nonyme  of  translucent.  A  body  which 
allows  the  forms  of  objects  to  be  seen 
through  it  is  transparent. 

DIASPORE.  A  laminated  mineral, 
composed  of  80  alumina,  18  water,  3  oxide 
of  iron.  A  small  fragment  decrepitates 
when  heated,  and  is  dispersed  in  numer- 
ous fragments :  hence  its  name. 

DIASTASE.  A  peculiar  substance 
generated  during  the  germination  of  bar- 
ley, wheat,  &c,  which  tends  to  accelerate 
the  formation  of  sugar  during  the  fer- 
mentation of  worts.  It  is  precipitated 
from  infusions  of  bruised  malt  by  alcohol. 
It  is  the  principle  which,  by  its  reaction 
on  starch,  tends  to  develop  sugar  in  the 
processes  of  germination  and  malting. 

DIE.  in  coinage,  is  the  instrument  by 
which  the  impressions  are  given  upon  the 
various  denominations  of  coin.  The  fol- 
lowing is  an  outline  of  the  die  manvfac- 
ture :  The  engraver  selects  a  forged  plug 
of  the  best  cast  steel  of  proper  dimen- 
sions for  his  intended  work,  and  having 
carefully  annealed  it,  and  turned  its  sur- 
faces smooth  in  the  lathe,  proceeds  to  en- 
grave upon  it  the  intended  device  for  the 
coin.  When  this  is  perfect,  the  letters  are 
put  in,  and  the  circularity  and  size  duly 
adjusted;  it  is  then  hardened,  and  is 
termed  a  matrix.  Another  plug  of  soft 
steel  is  now  selected,  and  the  matrix  be- 
ing carefully  adjusted  upon  it,  they  are 
placed  under  a  very  powerful  fly-press, 
and  two  or  three  blows  so  directed  as  to 
commence  an  impression  of  the  matrix 
upon  the  plug  ;  this  is  then  annealed,  and 
the  operation  repeated  till  the  plug  re- 
ceives a  perfect  impression  of  the  work 
upon  the  matrix.    This  impression  is  of 


i 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


course  in  relief,  the  original  work  upon 
the  matrix  being  indented,  and  produces 
what  is  termed  the  punch.  This  being 
duly  shaped  in  the  lathe,  is  hardened,  and 
is  employed  in  the  production  of  impres- 
sions in  soft  steel  or  dies,  which,  being 
properly  turned  and  hardened,  are  exact 
fac-similes  of  the  original  matrix,  and  are 
used  in  the  process  of  coinage.    When  a 

{>air  of  dies  are  made  of  good  steel  duly 
lardencd  and  tempered,  and  are  carefully 
used,  they  will  sometimes  yield  from  two 
to  three  hundred  thousaud  impressions 
before  they  become  so  far  worn  or  injured 
as  to  require  to  be  removed  from  the 
coh  ing  presses. 

DIFFERENTIAL  THERMOMETER. 
An  ingenious  instrument  of  great  use  in 
experimental  philosophy,  for  measuring 
very  small  differences  of  temperature ; 
invented  and  re-applied  by  Sir  John 
Leslie,  though  the  idea  of  an  instrument 
of  the  same  hind  seems  to  have  long  be- 
fore been  suggested  by  Sturmius.  The 
differential  thermometer  is  described  by 
Leslie,  in  his  Experimental  Inquiry  into 
the  Nature  and  Propagation  of  Meat,  nearly 
as  follows  :  Two  glass  tubes  of  unequal 
lengths,  each  terminating  in  a  hollow  ball, 
and  having  their  bores  somewhat  widened 
at  the  other  ends,  a  small  portion  of  sul- 
phuric acid  tinged  with  carmine  being  in- 
troduced into  the  ball  of  the  longer  tube, 
are  joined  together  by  the  flame  of  a  blow- 
pipe, and  afterwards  bent  into  nearly  the 
shape  of  the  letter  U;  the  one  flexure 
being  made  just  below  the  joining,  where 
the  small  cavity  facilitates  the  adjustment 
of  the  instrument,  which,  by  a  little  dex- 
terity, is  performed  by  forcing  with  the 
heat  of  the  hand  a  few  minute  globules 
of  air  from  the  one  ball  into  the  other. 
The  balls  are  blown  as  equal  as  the  eye 
can  judge,  and  from  four-tenths  to  seven- 
tenths  of  an  inch  in 
diameter.  To  one 
of  the  legs  of  the 
thermometer  a  scale 
is  attached ;  and  the 
liquid  in  the  tube  is 
so  disposed  that  it 
stands  in  the  gradu- 
ated  leg  opposite  the 
zero  of  the  scale, 
when  both  balls  are 
exposed  to  the  same 
temperature.  From 
this  construction  of 
the  instrument,  it  is 
easy  to  see  that  it  is 
affected  by  the  difference  only  of  heat  in 
the  two  balls.    As  long  as  both  balls  are 


of  the  same  temperature,  whatever  this 
may  be,  the  air  contained  in  the  one  will 
have  the  same  elasticity  as  that  contained 
in  the  other;  and  consequently  the  inter- 
eluded  colored  liquid,  being  thus  pressed 
equally  in  opposite  directions,  remains  sta- 
tionary. But  if,  for  instance,  the  ball 
which  holds  a  portion  of  the  liquor  be 
warmer  than  the  other,  the  superior  elas- 
ticity of  the  confined  air  will  drive  it  for- 
wards, and  make  it  rise  in  the  opposite 
branch  above  the  zero,  to  an  elevation 
proportional  to  the  excess  of  elasticity  or 
of  heat.  Sulphuric  acid  is  chosen  as  the 
liquor  best  adapted  to  the  purpose  ;  be- 
cause it  is  not  vaporizable,  and  conse- 
quently does  not  by  its  vapor  affect  the 
pressure  of  the  air  above  it.  The  car- 
mine is  used  to  render  it  more  easily 
visible. 

DIGESTER  is  the  name  of  a  strong 
kettle  or  pot  of  small  dimensions,  made 
very  strong,  and  mounted  with  a  safety 
valve  in  its  top.  Papin,  the  contriver  of 
this  apparatus,  used  it  for  subjecting 
bones,  cartilages,  &c,  to  the  solvent  ac- 
tion of  high-pressure  steam,  or  highly 
heated  water,  whereby  he  proposed  to 
facilitate  their  digestion  in  the  stomach. 
This  contrivance  is  the  origin  of  the 
French  cookery  pans,  called  autoclaves, 
because  the  lid  is  self-keyed,  or  becomes 
steam-tight  by  turning  it  round  under 
clamps  or  ears  at  the  sides,  having  been 
previously  ground  with  emery  to  fit  the 
edge  of  the  pot  exactly.  In  some  auto- 
claves the  hd  is  merely  laid  on  with  a 
fillet  of  linen  as  a  lute,  and  then  secured 
in  its  place  by  means  of  a  screw  bearing 
down  upon  its  centre  from  an  arched  bar 
above.  The  safety  valve  is  loaded  either 
by  a  weight  placed  vertically  upon  it,  or 
by  a  lever  of  the  second  kind  pressing 
near  its  fulcrum,  and  acted  upon  by  a 
weight  which  may  be  made  to  bear  upon 
any  point  of  its  graduated  arm. 

Chevreul  has  made  a  useful  application 
of  the  digester  to  vegetable  analysis.  His 
instrument  consists  of  a  strong  copper 
cylinder,  into  which  enters  a  tight  cylin- 
der of  silver,  having  its  edge  turned  over 
at  right  angles  to  the  axis  of  the  cylinder, 
so  as  to  form  the  rim  of  the  digester.  A 
segment  of  a  copper  sphere,  also  lined 
with  silver,  stops  the  aperture  of  the  sil- 
ver cylinder,  being  applied  closely  to  its 
rim.  It  has  a  conical  valve  pressed  with 
a  spiral  spring,  of  any  desired  force,  esti- 
mated by  a  steelyard'  This  spring  is  in- 
closed w;ithin  a  brass  box  perforated  with 
four  holes ;  which  may  be  screwed  into 
a  tapped  orifice  in  the  top  of  the  digester. 


128 


CYCLOPEDIA  OF  THE  USEFUL  AUTS. 


[dis 


A  tube  screwed  into  another  hole  serves 
to  conduct  away  the  condensable  vapors 
at  pleasure  into  a  Woulfe's  apparatus. 

1)1  MIT  Y  is  a  kind  of  cotton  cloth  ori- 
ginally imported  from  India,  and  now 
manufactured  in  great  quantities  in  vari- 
ous parts  of  Britain,  especially  in  Lanca- 
shire. Dr.  Johnson  calls  it  dimmity,  and 
describes  it  as  a  kind  of  fustian.  The 
distinction  between  fustian  and  dimity 
seems  to  be,  that  the  former  designates  a 
common  twilled  cotton  cloth  of  a  stout 
fabric,  which  receives  no  ornament  in  the 
loom,  but  is  most  frequently  dyed  after 
being  woven.  Dimity  is  also  a  stout  cot- 
ton cloth,  but  not  usually  of  so  thick  a  tex- 
ture ;  and  is  ornamented  in  the  loom, 
either  with  raised  stripes  or  fancy  figures  ; 
is  seldom  dyed,  but  usually  worn  white, 
as  for  bed  and  bed-room  furniture.  The 
striped  dimities  are  the  most  common ; 
they  require  less  labor  in  weaving  than 
the  others ;  and  the  mounting  of  the  loom 
being  more  simple,  and  consequently  less 
expensive,  they  can  be  sold  at  much  lower 
rates. 

DIPPEL'S  OIL.  An  empyreumatic 
oil,  produced  during  the  destructive  dis- 
tillation of  bone. 

DIPPER.  A  name  commonly  given  to 
the  water-ouzel  and  other  species  of  the 
genus  C Indus. 

DIPPING  NEEDLE.  An  instrument 
for  showing  the  direction  of  the  magnetic 
force  of  the  earth.  It  is  a  magnetic  nee- 
dle, furnished  with  an  axis  at  right  angles 
to  its  length,  and  passing  as  exactly  as 
possible  through  its  centre  of  gravity, 
about  which  it  moves  in  a  vertical  plane. 
When  a  needle  thus  mounted  is  placed 
any  where  not  on  the  magnetic  equator, 
it  dips,  or  points  downwards  :  and  if  the 
vertical  plane  in  which  it  moves  coincides 
with  the  magnetic  meridian  (which  is  al- 
ways known  by  means  of  a  variation  com- 
pass), the  position  which  it  assumes 
shows  at  once  the  direction  of  the  mag- 
netic force ;  and  the  intersection  of  two 
or  more  directions,  found  by  making  the 
experiment  at  different  places,  indicates 
the  place  of  the  magnetic  pole.  Though 
the  principles  on  which  the  dipping  needle 
acts  are  abundantly  simple,  its  practical 
construction  is  found  to  be  exceedingly 
difficult.  It  must  be  accurately  balanced 
on  its  axis ;  the  axis  must  be  placed  ex- 
actly horizontal ;  the  friction  must  be 
diminished  to  the  utmost  extent  possible ; 
and  the  adjustments  can  only  be  made 
when  the  needle  is  perfectly  free  from 
magnetism,  and  also  secured  from   the 


effects  of  the  magnetic  influence  of  the 
earth.  It  must  be  subsequently  magne 
tized,  and  during  this  process  much  care 
is  required  to  guard  against  derangement. 
The  simple  construction  is  represented 
in  the  annexed  figure.  The  needle  D  d 
consists  of  a  flat  oblong  piece  of  steel, 
tapering  to  a  point  at  both  ends,  and  hav- 
ing a  slender  cylindrical  axis  passed 
through  its  centre  of  gravity.  The  axis 
moves  freely  in  circu- 
lar holes  made  in  the 
lateral  horizontal  bars 
II  A,  which  support  a 
vertical  circular  C  C, 
graduated  for  the  pur- 
pose of  showing  the 
in clin ation  of  th e  nee- 
dle to  the  horizon. 
The  stand  S.  T,  to  which  the  circle  is 
fixed,  is  provided  with  levels,  and  ad- 
justed to  horizontality  by  means  of 
screws.  But  in  the  most  improved  form 
of  construction  of  the  dipping  needle, 
the  axis,  instead  of  being  a  cylinder,  is  a 
knife  edge,  resting  perpendicularly,  like 
the  supports  of  a  pendulum,  on  two  agate 
planes.  A  needle  thus  supported,  how- 
ever, must  necessarily  make  small  oscil- 
lations ;  consequently  it  must  be  so  ad- 
justed that  when  it  points  in  the  direc- 
tion of  the  magnetic  force,  the  knife  edges 
may  be  perpendicular  to  the  agate  planes. 
The  mean  value  of  the  angle  of  the  dip 
must  therefore  be  known  previously  to 
its  construction  ;  but  it  is  the  best  adapt- 
ed, on  account  of  its  delicacy,  for  ascer- 
taining the  minute  variations  of  the  dip 
at  the  same  place.  The  angle  of  the  dip, 
like  that  of  the  variation,  changes  its 
value  even  at  the  same  place,  following 
of  course  the  motion  ot  the  magnetic 
poles,  which,  from  the  observations  made 
by  Scoresby,  Parry,  Eoss,  and  others,  in 
high  latitudes,  appear  to  have  a  motion 
westward,  the  annual  amount  of  which  is 
about  11'  4".  In  the  summer  of  1831, 
Commander  Ross,  in  an  excursion  from 
the  vessel  in  which  his  party  were  so 
long  detained  in  the  polar  seas,  reached 
a  spot  on  the  continent  of  North  Ameri- 
ca, which  had  been  calculated  to  be  the 
position  of  the  magnetic  pole.  There  he 
found  the  dip  of  the  needle  to  be  S9°  59', 
within  one  minute  of  the  vertical ;  and 
i  compass-needles  suspended  in  the  most 
delicate  manner  possible  exhibit  no  pol- 
arity whatever.  The  latitude  of  this  spot 
is  70°  ;V  17"  north,  and  its  longitude  96° 
46'  4.">"  west. 
DISTILLATION.      The   evaporation 


DIS] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


129 


and  subsequent  condensation  of  liquids 
by  means  of  a  still  and  refrigeratory,  or 
of  a  retort  and  receiver. 

The  discovery  of  the  art  of  distillation 
is  generally  ascribed  to  the  alchemists  ; 
but  it  was  doubtlessly  known  in  more  re- 
mote ages  to  the  Arabians,  and  by  them 
probably  derived  from  nations  further 
east. 

The  process  of  distillation,  though  in 
continual  use  in  the  chemical  and  phar- 
maceutical laboratory,  is  carried  on  upon 
the  most  extensive  scale  for  the  produc- 
tion of  ardent  spirits  in  the  distilleries. 
Under  the  words  Alcohol,  Brandy,  Fer- 
mentation, Wine,  &c,  will  be  found  some 
details  bearing  upon  the  nature,  sources, 
and  production  of  spirituous  liquors. 

There  are  two  distinct  operations  in  the 
production  of  ardent  spirits  ;  the  one  is 
the  conversion  of  certain  vegetable  prin- 
ciples into  alcohol ;  and  the  other,  the 
separation  of  the  alcohol  from  the  other 
substances  with  which  it  is  necessarily 
blended  during  its  production. 

All  those  species  of  corn  which  are  em- 
ployed in  breweries  answer  for  distil- 
leries ;  as  wheat,  rye,  barley,  and  oats  ; 
as  well  as  buckwheat,  and  maize  or  In- 
dian corn.  The  product  of  spirits  which 
these  different  grains  afford,  depends 
upon  the  proportion  of  starch  they  con- 
tain, including  the  small  quantity  of  un- 
crystallizable  sugar  present  in  them. 
Hermstaedt,  who  has  made  exact  experi- 
ments upon  the  subject,  reckons  a  quart, 
(Trussian  or  British)  of  spirits,  contain- 
ing 80  per  cent,  of  the  absolute  alcohol 
of  Kichter,  for  two  pounds  of  starch. 
Hence  100  pounds  of  starch  should  yield 

35  pounds  of  alcohol ;  or  4-375  gallons 
imperial,  equal  to  7.8  gallons  of  spirits, 
excise  prool. 

100  pounds  of  the  following  grains 
afford  in  spirits  of  specific  gravity  0.9427, 
containing  45  per  cent,  of  absolute  alco- 
hol, (=  9-11  ot  British  proof,)  the  follow- 
ing quantities : — 

Wheat,  40  to  45  pounds  of  spirits  ;  rye, 

36  to  42  ;  barley,  40  ;  oats,  36  ;  buck- 
wheat, 40  ;  maize,  40.  The  mean  of  the 
whole  may  be  taken  at  forty  pounds, 
equal  to  4j  gallons  imperial,  of  0-9427 
specific  gravity  =  3-47  gallons,  at  excise 
proof.  The  chief  difference  in  these  sev- 
eral kinds  of  corn  consists  in  their  differ- 
ent bulks  under  the  same  weight ;  a  mat- 
ter of  considerable  importance  ;  for  since 
a  bushel  of  oats  weighs  little  more  than 
the  half  of  a  bushel  of  wheat,  the  former 
becomes  for  some  purposes  less  conve- 

6* 


nient  in  use  than  the  latter,  though  it 
affords  a  good  spirit. 

Barley  and  rye  are  the  species  of  grain 
most  commonly  employed  in  the  Euro- 
pean distilleries  for  making  whiskey. 
On  this  continent  corn  and  potatoes  are 
the  chief  materials  used  for  producing 
alcohol. 

The  vegetable  principle  which  is  es- 
sential to  the  formation  ot  alcohol  is  sugar  ; 
and  this  is  sometimes  used  directly,  as 
where  molasses  and  analogous  saccharine 
products  are  subjected  to  immediate  fer- 
mentation 5  or  it  is  indirectly  obtained  by 
subjecting  amylaceous  grains  to  certain 
processes,  by*  which  the  starch  they 
contain  is  first  converted  into  sugar, 
and  then  that  sugar  afterwards  alcoho- 
lized. 

In  distilleries  the  latter  alternative  is 
adopted ;  and  various  kinds  of  grain,  but 
chiefly  barley,  wheat,  and  rye,  with  more 
or  less  malt,  are  subjected  to  the  opera- 
tion of  mashing.  For  this  purpose  the 
§  round  grain  and  the  bruised  malt  are 
uly  mixed,  and  infused  under  constant 
agitation  in  a  proper  quantity  of  hot 
water  in  the  mash-tub  ;  the  wort  is  then 
run  off,  and  fresh  water  added,  till  the 
soluble  materials  of  the  grain  are  ex- 
tracted. 

In  this  way  the  mixed  worts  or  wash  is 
obtained,  which  is  afterwards  to  be  sub- 
jected to  fermentation  ;  but  in  the  dis- 
tilleries of  Great  Britain  the  operator  is 
not,  as  in  the  brewery,  left  to  his  own 
judgment  or  convenience,  but  enforced 
to  conform  to  the  excise  laws,  which  are 
of  a  very  peremptory  and  often  of  a  very 
unscientific  character.  By  these  laws 
the  distiller  is  restricted  in  the  density  of 
his  worts  to  specific  gravities  between 
1050  and  1090  ;  and  in  Scotland  between 
1030  and  1075.  It  is  presumed  that  as 
those  specific  gravities,  which  are  called 
50  and  90,  and  30  and  75,  the  actual  quan- 
tity of  saccharine  or  saccharifiable  matter 
contained  in  each  barrel  (or  36  imperial 
gallons)  amounts  respectively  to  from 
47  £  lbs.  to  85  lbs.,  and  from  28  lbs.  to 
79  3-10  lbs.  In  this  country  the  distiller 
is  untrammelled. 

When  the  wash  above  alluded  to  is  ad- 
justed as  to  density,  it  is  run  into  the 
fermenting  vats,  where,  mixed  with  a 
small  quantity  of  yeast,  it  is  subjected  to 
the  process  of  fermentation,  which  con- 
tinues from  six  to  ten  or  twelve  days, 
the  time  required  for  its  completion  vary- 
ing with  the  mass  of  liquid  and  with  the 
temperature  of  the  atmosphere. 


130 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[dis 


During  mashing,  as  well  as  during  fer- 
mentation, the  starch  passes  into  sugar, 
and  the  sugar  into  alcohol ;    the  conse- 

Suence  of  which  is  that  the  wash  gradu- 
ily  decreases  in  density  or  attenuates; 
and.  as  soon  as  this  attenuation  has  reach- 
ed its  maximum,  which  may  be  deter- 
mined by  the  hydrometer,  it  should  be 
distilled,  in  order  to  prevent  the  access 
of  acetous  fermentation. 

In  all  large  distilleries  there  are  two 
sets  of  stills  :  one  for  the  purpose  of  dis- 
tilling from  the  wash  a  weak  spirit,  tech- 
nically called  low  wines;  and  the  other 
for  redistilling  (or  rectifying)  the  low 
wines.  In  these  distillations  there  passes 
over  along  with  the  first  and  last  portions 
of  the  spirits  a  peculiar  volatile  oil  of  a 
disagreeable  flavor  and  odor,  and  render- 
ing the  weaker  spirit  milky.  These  por- 
tions are  c&MedJaints,  and  are  carefully 
turned  into  separate  receivers  as  soon  as 
the  appearance  of  the  runnings  from  the 
worm-end  indicates  their  presence. 

The  quantity  of  alcohol  which  may  be 
obtained  from  a  given  quantity  of  sugar 
will  depend  upon  the  skill  and  care  with 
which  mashing,  fermentation,  and  distil- 
lation have  been  respectively  conducted  ; 
theoretically,  100  pounds  of  sugar  are 
convertible  into  about  51  of  alcohol  and 
49  of  carbonic  acid.  The  quantity  of  al- 
cohol to  be  procured  from  different  kinds 
of  grain  will  also  depend  upon  the  same 
causes,  and  upon  the  quantity  of  sugar, 
and  of  starch  and  gum  convertible  into 
sugar,  which  each  may  contain. 

Sometimes  malt  only  is  used  ih  the  dis- 
tillery, in  which  case  the  distiller  calcu- 
lates in  obtaining  two  gallons  of  whiskey 
of  proof  strength  from  each  bushel  of 
malt.  In  some  distilleries  as  much  as 
3000  gallons  per  day  are  produced,  and 
the  wonn  of  the  still  is  passed  into  the 
body  of  a  second  still,  so  that  the  heat 
arising  from  the  condensation  ha  the 
worm  raises  the  temperature  in  the  second 
still,  and  thus  economises  fuel. 

There  is  a  kind  of  ardent  spirits  man- 
ufactured in  Holland,  vulgarly  called 
Dutch  gin,  Hollands,  and  sometimes 
geneva,  from  genievre,  the  French  for 
juniper,  a  plant  with  the  essential  oil  of 
whose  berries  it  is  flavored.  One  cwt. 
of  ground  malt  mixed  with  two  cwts.  of 
rye  meal  are  mashed  for  two  hours,  with 
about  450  gallons  of  water  at  the  temper- 
ature of  160°  F.  The  mash  drawn  off  is 
reduced  with  cold  water  till  the  liquid 
part  has  the  density  of  45  lbs.  per  barrel, 
=  specific  gravity  1*047;  and  is  then  put 
altogether  into  the  fermenting  back  at 


the  temperature  of  80°  F.  One  or  two 
gallons  of  yeast  are  added.  The  fermen- 
tation soon  becomes  so  vigorous  as  to 
raise  the  heat  to  90°  and  upwards,  but  it 
is  not  pushed  far,  being  generally  over 
in  two  days,  when  the  gravity  of  the 
wash  still  indicates  12  lbs.  of  saccharurn 
per  barrel.  By  this  moderate  attenua- 
tion, like  that  practised  by  the  contra- 
band distillers  of  the  Highlands  of  Scot- 
land, it  is  supposed  that  the  fetid  oil  of 
the  husks  is  not  evolved,  or  at  least  in 
very  small  quantity.  The  grains  are  put 
into  the  alembic  along  with  the  liquid 
wash*,  and  distilled  into  low  wines,  which 
are  rectified  twice  over,  some  juniper  ber- 
ries and  hops  being  added  at  the  last  dis- 
tillation. But  the  junipers  are  some 
times  bruised  and  put  into  the  mash. 
The  produce  of  worts  so  imperfectly  fer- 
mented, is  probably  little  more  than  one 
half  of  what  the  British  distiller  draws 
from  the  same  quantity  of  grain.  But 
the  cheapness  of  labor  and  of  grain,  as 
well  as  the  superior  flavor  of  the  Skie- 
dam  spirits,  enables  the  Dutch  distiller 
to  carry  on  his  business  with  a  respecta- 
ble profit.  In  opposition  to  the  above 
facts,  Dubrunfaut  says  that  about  one 
third  more  spirits  are. obtained  in  Hol- 
land from  grain  than  in  France,  because 
a  very  _  calcareous  spring  water  is  em- 
ployed in  the  mashing  operation.  Were 
this  account  well  founded,  all  that  the  dis- 
tillers of  other  countries  would  have  to  do 
would  be  merely  to  introduce  a  portion  of 
chalk  into  their  mash  tubs,  in  order  to 
be  on  a  par  with  the  Dutch.  But  the 
statement  is  altogether  a  mistake. 

In  the  vine  countries,  the  inferior 
wines,  or  those  damaged  by  keeping,  as 
also  a  fermented  mash  of  the  pressed 
grapes,  mixed  with  water,  are  distilled  to 
form  the  eau  de  vie  de  Cognac  of  the 
French,  called  Brandy  in  tins  country. 
It  contains  less  essential  oil,  and  that  of 
a  more  agreeable  flavor,  than  corn  spirits. 

Of  making  wliisJcey  from  potatoes. — 
This  root,  in  certain  localities  where  it 
abounds  at  a  moderate  price,  is  an  ex- 
cellent material  for  fermenting  into  al- 
cohol. When  sound,  it  possesses  from 
20  to  25  per  cent,  of  solid  substance,  of 
which  starch  constitutes  at  least  three- 
fourths  ;  hence  100  pounds  contain  from 
16  to  22  pounds  of  starch  susceptible  of 
being  saccharified.  In  the  expressed 
juice  there  is  a  small  quantity  of  tartaric 
acid. 

As  potatoes  readily  pass  into  the  ace- 
tous fermentation,  the  admixture  of  the 
malt,  the  mashing  and  the  cooling  should 


Div] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


131 


be  rapidly  performed,  while  the  utmost 
cleanliness  must  be  observed. 

The  fermentation  is  brisk,  probably 
from  the  agency  of  the  albumen,  and  fur- 
nishes a  good  head  of  barm,  which  an- 
swers well  for  the  bakers ;  100  pounds 
of  potatoes  yield  from  18  to  20  pounds 
measure  of  spirits,  nine-elevenths  of  our 
excise-proof;  or  about  16  pounds  mea- 
sure of  proof  =  about  1|  gallons. 

It  has  been  observed  that  after  the 
month  of  December  potatoes  begin  to 
yield  a  smaller  product  of  fermented 
spirits;  and  when  they  have  once  sprout- 
ed or  germinated,  they  afford  very  little 
indeed^  From  the  difficulty  of  keeping 
and  transporting  potatoes,  distillation 
from  them,  can  never  become  general  till 
some  plan  be  adopted  for  overcoming 
these  disadvantages. 

When  acetic  ether  is  added  to  well  pu- 
rified or  clean  spirits,  such  as  the  distil- 
lers call  silent  whiskey,  it  gives  it  some- 
what of  the  flavor  of  brandy.  For  this 
purpose,  also,  the  spirits  are  rectified 
from  bruised  prunes,  or  the  lees  of  the 
cognac  distilleries,  whereby  they  acquire 
additional  flavor.  The  astringent  taste 
of  old  brandy  is  imitated  by  "the  intro- 
duction of  a  little  catechu  into  the  British 
spirits.  Burned  sugar  is  employed  as  a 
coloring  in  these  imitations.  Butyric  ether 
gives  a  pine-apple  flavor. 

DIVING  BELL.      An  apparatus  by 
means   of  which  persons   are  let  down 
and  enabled  to  remain  under  water,  and 
execute  various  operations  ;    such  as  le- 
velling or  clearing  the  bottoms  of  har- 
bors, preparing  a  foundation  for  build- 
ings, bringing  up  sunken  materials,  &c. 
The  principle  of  the  diving  bell  depends 
on   the   impenetrability   of  atmospheric 
air,  and  may  be  illustrated  by  a  very  fa- 
miliar experiment.     Bring  the  edge  of 
an  inverted  tumbler,  or  any  close  vessel, 
to  the  surface  of  water,  and,  keeping  the 
mouth  horizontal,  press  it  down  in  the 
water.      It  will   be    seen    that,   though 
some  portion  of  water  ascends  into  the 
tumbler,  the  greater  part  of  the  space 
remains  empty,  or  only  filled  with  air; 
and   any  object    placed    in  this   space, 
though  surrounded  on    all   sides   with  j 
water,  would  remain  perfectly  dry.     In  I 
fact,   the  quantity   of  air    remains   the  j 
same,  but  it  is  compressed  into  a  smaller  j 
volume,  in  proportion  to  the  depth  to  i 
which  it  is  made  to  descend.     Isow,  if 
we  conceive  a  vessel  of  wood  or  iron,  { 
sufficiently  capacious  to  hold  several  men,  | 
to  be  suspended  by  a  chain,  and  lowered  | 
by  means  of  weights  attached  to  it,  to  i 


any  moderate  depth  under  water,  it  is 
evident  that  they  may  remain  there  for  a 
considerable  time,  and  perform  any  ope- 
ration that  could  be  executed  on  land  in 
the  same  confined  space.  The  machine, 
however,  as  thus  described,  is  liable  to 
two  great  defects,  which  must  be  obvi- 
ated by  other  contrivances  before  any 
great  advantage  can  be  derived  from 
it.  In  the  first  place,  as  the  air  by  its 
compressibility  allows  the  water  to  enter 
the  lower  part  of  the  bell,  the  dry  space 
is  not  only  diminished,  but  the  bottom 
on  which  the  bell  rests,  and  where  the 
operations  are  to  be  carried  on,  is  also 
covered  with  water  to  a  proportional 
depth.  In  the  second  place,  the  air 
within  the  bell,  by  repeated  respiration, 
soon  becomes  mephitic,  and  unfit  to  sup- 
port life  ;  so  that  it  is  necessary  to  ele- 
vate the  apparatus  after  short  intervals, 
to  admit  a  fresh  supply. 

It  is  not  known  at  what  period  the 
diviner  bell  was  invented.  Beckmann,  in 
his  History  of  Inventions,  mentions  that 
at  Toledo,  in  the  sixteenth  century,  two 
Greeks,  in  the  presence  of  the  emperor 
Charles  V.  and  several  thousand  specta- 
tors, let  themselves  down  under  water 
in  a  large  inverted  kettle  with  a  burning 
light,  and  rose  again  without  being  wet. 
George  Sinclair,  the  author  of  Satan's  In- 
visible World  Displayed,  in  his  work  en- 
titled Ars  Nova  et  Magna  Gravitatis  et 
Levitatis,  mentions  some  attempts  that 
were  made  about  1665  to  raise,  by  means 
of  a  diving  bell,  the  treasure  from  the 
ships  of  the  Invincible  Armada  that  went 
to  the  bottom  near  the  Isle  of  Mull  in 
the  Hebrides,  and  describes  the  kind  of 
bell  that  was  employed.  But,  on  account 
of  the  defects  to  which  we  have  alluded, 
the  diving  bell  continued  to  be  of  very 
little  use  till  the  time  of  Dr.  Halley,  who 
contrived  a  means  of  introducing  fresh 
air  into  the  bell  while  under  water,  and 
of  allowing  the  mephitic  or  breathed  air 
to  escape.  The  bell  he  made  use  of  he 
describes  as  having  been  of  wood,  con- 
taining about  60  cubic  feet  in  its  cavity, 
and  of  the  form  of  a  truncated  cone, 
whose  diameter  at  the  top  was  three 
feet,  and  at  the  bottom  five.  This  was 
coated  with  lead,  so  heavy  that  it  could 
sink  empty,  ana  the  weight  so  distri- 
buted about  its  bottom  that  it  could  only 
descend  in  a  perpendicular  direction 
In  the  top  a  clear  glass  was  fixed,  to  let 
in  the  light  from  above,  and  a  cock  to  let 
out  the  air  that  had  been  breathed.  To 
supply  the  air  to  the  bell  he  caused  a 
couple  of  barrels,   of  about  36  gallons 


132 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[div 


each,  to  be  cased  with  lead  so  as  to  sink 
empty,  each  of  them  having  a  bung-hole 
in  its  lowest  part,  to  let  in  the  water  as 
the  air  in  them  condensed  on  their  de- 
scent, and  to  let  it  out  again  when  they 
were  drawn  up  full  from  below.  To  a 
hole  in  the  uppermost  part  of  the  barrels 
a  trunk  or  hose  was  fixed,  long  enough 
to  fall  beloAV  the  bung-hole,  and  kept 
down  by  a  weight,  sothat  no  air  could 
escape  by  the  hose  till  its  end  was  raised 
up.  The  barrels  thus  prepared  were  let 
down  by  the  side  of  the  bell.  A  man 
stationed  on  a  stage  suspended  from  the 
bell  was  ready  to  take  up  the  hose  ;  and, 
as  soon  as  their  ends  were  brought  t^ 
the  surface  of  the  water  in  the  barrels, 
all  the  air  that  was  included  in  the  upper 

f>arts  of  them  was  blown  with  great  vio- 
ence  into  the  bell,  while  the  water  en- 
tered at  the  bung-holes  below  and  filled 
the  barrels.  By  means  of  this  contriv- 
ance the  air  was  not  only  kept  fresh,  but 
another  great  advantage  was  gained ; 
namely,  that  by  admitting  a  sufficient 
quantity  of  it  the  whole  of  the  water  was 
expelled  from  the  inside  of  the  bell,  and 
the  bottom  of  the  sea  laid  dry. 

By  means  of  this  contrivance  for  the 
admission  of  fresh  air,  it  was  now  pos- 
sible to  remain  for  any  length  of  time 
Tinder  water ;  but  the  use  of  the  appara- 
tus was  still  found  to  be  attended  with 
some  inconveniences,  and  even  consider- 
able danger.  The  divers  within  the  bell 
having  no  power  over  it,  its  rising  or 
sinking  depends  entirely  upon  the  peo- 
ple at  the  surface  of  the  water ;  and  as 
the  bell,  even  when  in  the  water,  has  a 
considerable  weight,  there  is  always  a 
possibility  of  the  chain  by  which  it  is 
raised  breaking,  which  would  inevitably 
be  attended  with  the  destruction  of  the 
divers.  Another  danger,  still  more  to  be 
apprehended,  is,  that  if  the  mouth  of  the 
bell  in  its  descent  should  come  upon  a 
sunken  ship,  or  a  roek  projecting  ab- 
rup:ly  from  the  bottom,  it  might  be 
overset  before  any  signal  could  be  given 
to  those  above.  These  defects  were  ob- 
viated by  the  very  ingenious  contrivances 
of  Mr.  Spalding  of  Edinburgh.  In  order 
to  avoid  the  risk  of  being  upset  when 
the  bell  descends  on  a  rocky  or  uneven 
bottom,  he  suspended  a  considerable 
weight,  which  is  called  a  balance  weight, 
below  the  bell,  by  a  rope  passing  over  a 
pulley  fixed  in  the  inside  ;  and  the  other 
weights  attached  to  the  bell  being  so 
adjusted  that  they  could  not  sink  it 
without  the  balance  weight,  as  soon  as 
the  latter  rested  on  the  ground  the  bell 


remained  suspended  in  the  water.  In 
case  of  the  mouth  of  the  bell  being 
caught  by  any  obstacle,  the  balance 
weight  is  immediately  lowered,  till  it 
rests  on  the  bottom ;  and  as  the  bell, 
when  thus  relieved,  is  buoyant,  the  di- 
vers, having  disengaged  it  from  the  rock, 
have  it  in  their  power  either  to  descend 
by  pulling  in  the  rope,  or  by  allowing  it 
to  run  to  ascend  to  the  surface.  Another 
contrivance  of  Mr.  Spalding  deserves 
mention.  He  divided  the  bell  into  two 
compartments,  the  one  above  the  other, 
and  communicating  by  means  of  a  stop- 
cock. The  divers  are  stationed  in  the 
lower  one,  and  the  weights  are  so  ad- 
justed that  when  the  cavity  above  is 
empty  the  bell  is  buoyant;  when  it  is 
filled  with  water,  the  bell  sinks.  Imme- 
diately above  the  partition  are  some  slits 
in  the  sides  of  the  bells  ;  and  at  the  top 
is  an  orifice,  which  can  be  opened  or 
shut  at  pleasure.  Suppose  now,  this 
orifice  being  open,  the  bell  is  required  to 
be  lowered ;  as  it  descends,  the  water 
enters  at  the  slits,  and  the  air  escapes  by 
the  orifice.  When  the  apparatus  is  en- 
tirely under  water,  and  the  cavity  conse- 
quently completely  filled,  let  the  orifice 
be  shut.  The  bell  will  now  continue  to 
descend  ;  but  if  the  stopcock  communi- 
cating with  the  upper  compartment  be 
opened,  the  air  will  rush  from  the  under 
to  the  upper,  and  displace  a  quantity  of 
the  water,  and  the  apparatus  will  be 
lightened  by  the  whole  of  the  water  so 
displaced.  The  divers  have  it  thus  in 
their  power  to  regulate  the  descent  or 
rise  as  they  please.  By  admitting  a  cer- 
tain quantity  of  air  into  the  upper  cavity, 
the  descent  of  the  bell  is  arrested;  by 
admitting  a  greater  quantity  it  becomes 
buoyant,  and  rises  to  the  top.  This  me- 
thod of  constructing  the  diving  bell  has 
not,  however,  been  adopted. 

The  greatest  improvement  on  the  div- 
ing bell,  since  that  of  Halley,  was  made 
by  the  celebrated  Mr.  Smeaton,  and  con- 
sists in  forcing  down  a  continued  stream 
of  air  by  means  of  an  air-pump  through 
a  flexible  tube  ;  and  this  plan  is  now  al- 
ways adopted.  In  the  year  1788,  Smea- 
ton constructed  a  diving  bell  to  be  used 
in  the  operations  then  contemplated  at 
Bamsgate  harbor  on  a  new  and  improved 
plan.  Instead  of  a  bell-shaped  vessel 
sunk  by  weights,  his  apparatus  consisted 
of  a  square  chest  of  cast  iron,  four  and  a 
half  feet  long,  four  and  a  half  feet  high, 
and  three  feet  wide,  affording  sufficient 
room  for  two  men  under  it.  It  was  cast 
of  such  a  thickness  that  its  own  weight 


DIV] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


133 


was  sufficient  to  sink  it ;  and  its  thick- 
ness was  greatest  near  the  mouth  or 
lower  part,  to  prevent  it  from  being 
easily  overset.  Thi3  construction  of  the 
diving  bell  gave  the  men  jyithin  it  no 
power  of  raising  or  sinking  it ;  but  as 
the  apparatus  was  made  to  be  used  at  a 
place  where  the  nature  of  the  bottom 
was  known,  this  advantage  was  not  con- 
sidered of  great  consequence  ;  and,  in 
fact,  it  is  found  by  experience  that  it  is 
better  to  leave  the  bell  to  be  entirely 
guided  from  above.  On  account  of  the 
facility  with  which  water  conveys  sound, 
the  strokes  of  a  hammer  on  the  inside  of 
the  bell  can  be  heard  at  a  great  distance  ; 
and  the  sound  coming  through  the 
water  has  a  peculiar  character,  which 
cannot  be  mistaken.  By  previous  ar- 
rangements any  directions  can  be  given 
in  this  manner.  For  instance,  one  blow 
may  denote  more  air ;  two,  stand  fast ; 
three,  heave  up ;  four,  lower  down,  and 
so  on.  With  these  successive  improve- 
ments, the  diving  bell  is  found  to  be  a 
most  important  machine  in  all  the  great 
operations  to  be  performed  under  water. 
It  was  used  with  great  advantage  by  Mr. 
Kennie  in  the  construction  of  the  various 
harbors  he  projected ;  and  it  has  recently 
been  successfully  employed  in  deepening 
the  Clyde  between  Glasgow  and  Green- 
ock, and  improving  the  condition  of  the 
river. 

DIVING.  The  art  of  descending  in 
water.  Independently  of  the  valuable 
native  productions  which  are  found  at 
the  bottom  of  the  sea,  such  as  pearls, 
coral,  sponges,  &c,  the  treasure  which 
is  so  frequently  carried  down  in  wrecked 
vessels  makes  it  an  object  of  importance 
to  be  able  to  descend'to  the  bottom  and 
remain  there  long  enough  to  execute  the 
operations  necessary  to  recover  it.  But 
without  the  assistance  of  some  mechani- 
cal apparatus,  it  is  extremely  little  that 
even  the  most  practised  divers  can  per- 
form. A  minute  and  a  half,  or  two 
minutes,  is  the  longest  time  that  a  diver, 
in  general,  can  remain  under  water.  Be- 
sides, on  account  of  the  loss  of  weight  in 
water,  the  power  which  a  man  can  exert 
is  extremely  small,  unless  borne  down 
by  a  load  which  would  entirely  prevent 
him  from  rising  again  to  the  top.  For 
these  reasons,  numerous  projects  have 
been  brought  forward  to  assist  the  natural 
powers  of  the  body,  and  render  diving 
an  art  of  more  extensive  utility.  In  all 
these  projects,  the  principal  object  aimed 
at  is  to  supply  the  diver  with  fresh  air 
and  light,  and  leave  him  the  free  use  of 


his  arms,  and  the  power  of  walking 
within  a  moderate  range  at  the  bottom. 
Borelli  contrived  an  apparatus  which  he 
called  a  diving  bludder;  the  bladder  be- 
ing of  brass  or  copper,  about  two  feet  in 
diameter,  to  contain  the  diver's  head, 
and  fastened  to  a  goat-skin  covering  ex- 
actly fitted  to  the  shape  of  the  head.  An 
apparatus  of  this  kind  was  successfully 
used  by  Mr.  Deane  on  the  west  coast  of 
Scotland,  at  Spithead,  and  at  Donagha- 
dee,  where  he  brought  up  an  immense 
number  of  dollars  and  various  other  ar- 
ticles from  a  vessel  which  had  been 
wrecked  there  more  than  thirty  years 
before. 

The  principal  part  of  Mr.  Deane's  ap- 
paratus consists  of  a  helmet  of  thin  sheet 
copper,  which  covers  the  head  of  the 
diver,  large  enough  to  admit  of  free  mo- 
tion, and  furnished  with  three  eye-holes, 
covered  with  glass  protected  by  brass 
wires.  The  helmet  comes  pretty  well 
down  over  the  breast  and  back,  and  is 
fastened  by  rivets  to  a  waterproof  can- 
vass jacket  so  tightly  that  no  water  can 
penetrate.  A  leather  belt  passes  round 
the  diver,  to  which  are  attached  two 
weights,  one  before  and  the  other  be- 
hind, each  about  40  lbs.  The  belt  is 
supplied  with  a  buckle  in  front,  which, 
in  case  of  any  accident  happening,  can 
be  instantly  undone.  The  diver  is  sup- 
plied with  fresh  air  by  means  of  a  flexi- 
ble water-proof  pipe,  which  enters  the 
helmet,  and  communi- 
cates with  an  air-pump, 
wrought  above  m  the 
barge" from  which  he  de- 
scends. This  pipe  pas- 
ses under  the  left  arm 
of  the  diver,  and  enters 
the  back  of  the  helmet, 
being  so  contrived  that 
the  fresh  air  is  made  to 
impinge  on  the  glasses ;  which  in  a  great 
measure  prevents  their  being  dimmed  by 
the  moisture  of  the  breath.  From  the 
back  part  of  the  helmet  there  is  also  led 
an  eduction  pipe,  to  allow  the  escape  of 
the  breathed  air.  A  single  line  passes 
under  the  right  arm  to"  communicate 
with  attendants  at  the  surface.  The 
diver  descends  from  the  side  of  the  ves- 
sel, either  by  means  of  a  rope  or  wooden 
ladder,  loaded  at  the  lower  end,  the 
weight  being  kept  at  a  little  height  above 
the  ground.  When  the  diver  descends 
to  the  bottom,  the  weight  is  let  down, 
and  the  rope  allowed  to  become  slack,  to 
prevent  the  motion  of  the  boat  from  ob- 
structing him.    His  motion  is  rendered 


134 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


|dra 


steady  by  heavy  weights  attached  to  his 
feet :  and  he  carries  a  line  in  his  hand, 
that  he  may,  when  necessary,  guide  him- 
self back  to  the  rope.  A  waterproof 
dress  covers  his  body  entirely ;  and  he  is 
thus  enabled  to  remain  under  water  five 
or  six  hours  at  once,  all  the  while  per- 
fectly drv. 

DIVISIBILITY.  The  property  which 
all  bodies  possess  of  being  separable  into 
parts.  It  was  a  question  formerly  much 
agitated  among  philosophers,  whether 
matter  is  divisible  in  infinitum ;  or 
whether  a  certain  term  does  not  exist 
beyond  which  the  particles  are  reduced 
to  simple  atoms  incapable  of  further  di- 
vision. The  question  is  incapable  of  di- 
rect solution,  and  fortunately  is  of  no 
importance  to  science  ;  but  the  extent  to 
which  the  actual  subdivision  of  bodies 
has  been  carried  in  many  cases  in  the 
arts  may  well  be  considered  as  prodigious. 
"In  the  gilding  of  buttons,  5  grains  of 
gold,  which  is  applied  as  an  amalgam 
with  mercury,  is  allowed  to  each  gross  ; 
so  that  the  coating  left  must  amount  to 
the  110,000th  part  of  an  inch  in  thick- 
ness. If  a  piece  of  ivory,  or  white  satin, 
be  immersed  in  a  nitro-muriate  solution 
of  gold,  and  then  exposed  to  a  current 
of  hydrogen  gas,  it  will  become  covered 
with  a  surface  of  gold  hardly  exceeding 
in  thickness  the  ten-millionth  part  of  an 
inch. 

"  The  solution  of  certain  saline  bodies, 
and  of  other  colored  substances,  exhibits 
a  prodigious  subdivision  and  dissemina- 
tion of~matter.  A  single  grain  of  the 
sulphate  of  copper,  or  blue  vitriol,  will 
communicate  a  fine  azure  tint  to  five  gal- 
lons of  water.  In  this  case  the  copper 
must  be  attenuated  at  least  ten  million 
times  ;  yet  each  drop  of  the  liquid  may 
contain  so  many  colored  particles,  dis- 
tinguishable by  our  unassisted  vision. 
Odors  are  capable  of  a  still  wider  diffu- 
sion. A  single  grain  of  musk  has  been 
known  to  perfume  a  room  for  the  space 
of  twenty  years.  Animal  matter  like- 
wise exhibits  in  many  instances  a  won- 
derful subdivision.  The  milt  of  a  cod- 
fish when  it  begins  to  putrefy  has  been 
computed  to  contain  a  billion  of  perfect 
insects,  so  that  thousands  of  these  living 
creatures  could  be  lifted  on  the  point  of 
a  needle.  But  the  infusory  animalcules 
display  in  their  structure  and  functions 
the  most  transcendant  attenuation  of 
matter.  The  Vibrio  undvla,,  found  in 
duck  weed,  is  computed  to  be  ten  thou- 
sand million  times  smaller  than  a  hemp 
seed.    The  Vibrio  lineola  occurs  in  vege- 


table infusions,  every  drop  containing 
myriads  of  these  oblong  points.  The 
Monas  gelatinosa,  discovered  in  ditch  wa- 
ter, appears  in  the  field  of  a  microscope 
a  mere  ator^  endued  with  life,  millions 
of  them  playing  like  sunbeams  in  a  single 
drop  of  liquid." 

DOCTMASTIC  ART.  The  art  of  as- 
saying minerals  or  ores,  with  a  view  of 
determining  the  quantity  of  metal  which 
they  contain. 

DOCK.  An  artificial  basin  for  the  re- 
ception of  ships.  Docks  are  of  two  sorts, 
wet  and  dry :  the  former  are  used  for 
the  purpose  of  loading  and  unloading  a 
ship^s  cargo  out  of  the  influence  of  the 
tide,  and  are  constructed  with  gates, 
which  when  shut  keep  the  ship  con- 
stantly on  float  at  low  water ;  the  latter 
are  intended  for  the  building,  repairing, 
or  examination  of  ships,  which  ar.  ad- 
mitted into  them  at  flood  tide,  and  are 
so  called  because  they  are  either  left  dry 
by  the  ebbing  of  the  sea,  or  rendered  so 
by  the  use  of  great  flood  gates  or  of 
pumps.  A  naval  dock  is  a  place  provided 
with  all  sorts  of  naval  stores,  timber, 
and  all  the  requisite  machinery  for  ship- 
building. 

DRAGON'S  BLOOD  is  a  resinous 
substance,  which  comes  to  us  sometimes 
in  small  balls  of  the  size  of  a  pigeon's- 
egg,  sometimes  in  rods,  like  the  finger, 
and  sometimes  in  irregular  cakes.  Its 
color,  in  lump,  is  dark  brown  red;  in 
powder,  bright  red :  friable ;  of  a  shining 
fracture;  sp.  grav.,' 1-196.  It  contains  a 
little  benzoic  acid,  is  insoluble  in  water, 
but  dissolves  readily  in  alcohol,  ether, 
and  oils.  It  is  brought  from  the  East 
Indies,   Africa,  South   America,   as  the 

Sroduce  of  several  trees,  the  Dracana 
h-aco,  the  Pterocarpus  santalinus,  the 
Pterocarpus  Draco,  and  the  Calamus  Bo- 
tang. 

Dragon's  blood  is  used  chiefly  for 
tingeing  spirit  and  turpentine  varnishes, 
for  preparing  gold  lacker,  for  tooth  tinc- 
tures and  powders,  for  staining  marble, 
&c.  According  to  Herbenger,  it  consists 
of  9-07  parts  ofred  resin,  2  of  fat  oil,  3  of 
benzoic  acid,  1-6  of  oxalate,  and  3-7  of 
phosphate  of  lime. 

DRAINING.  The  art  of  freeing  the 
surface  of  the  soil  from  superfluous  wa- 
ter, considered  with  reference  to  culti- 
vated vegetables,  and  the  health  of  man 
and  animals.  "Water  may  become  super- 
fluous by  being  collected  in  the  natural 
hollows  on  the  surface,  and  thus  form- 
ing bogs ;  by  being  retained  in  the  sur- 
face stratum,  in  consequence  of  a  reten- 


dra] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


135 


tive  subsoil ;  or  by  oozing  through  a 
moist  subsoil  to  the  surface  stratum,  in 
consequence  of  supplies  from  subter- 
raneous sources.  Water  collected  in  bogs, 
or  marshy  places,  remains  there,  because 
it  has  no  natural  outlet,  neither  by  an 
opening  or  hollow  along  the  natural  sur- 
face, nor  by  the  porosity  of  the  subsoil, 
in  consequence  of  which  the  water  might 
sink  into  it  and  disappear.  The  obvious 
mode  of  draining  in  the  first  case  is  by 
a  trench  or  drain,  so  deep  as  to  draw 
the  water  from  the  lowest  parts  of  the 
hollow,  bog,  or  marsh.  Where  water  is 
retained  in  the  surface  soil  in  conse- 
quence of  a  retentive  subsoil,  as  in  the 
case  of  clays  and  many  loams,  the  most 
effective  mode  is  to  cut  a  number  of  small 
drains  parallel  to  and  at  short  distances 
from  one  another ;  and  by  the  tops  of 
these  drains  reaching  within  an  inch  or 
two  of  the  bottom  of  the  surface  soil, 
which  in  cultivation  is  turned  over  by 
the  plough,  they  absorb  the  superfluous 
water  that  passes  through  this  soil  and 
carry  it  off.  Or,  should  the  land  be  in 
pasture,  the  tops  of  the  drain  should  be 
brought  within  an  inch  or  two  of  the 
grassy  surface,  so  as  to  intercept  the 
water,  both  oozing  laterally  from  the  sur- 
face soil,  and  vertically  from  among  the 
leaves  of  the  grass.  It  may  be  observed 
also  that  pasture  lands  on  this  descrip- 
tion of  retentive  soil  may  be  more  rea- 
dily drained  when  laid  into  ridges,  and 
an  underground  drain  formed  under  each 
furrow  or  surface  drain.  This,  however, 
is  not  essential  ;  and  though  furrows  or 
surface  drains  would  be  no  deformity  in 
field  culture,  yet  in  lawns  and  parks  the 
appearance  of  furrows  would  destroy  the 
continuity  and  evenness  of  surface,  which 
in  lawns  is  one  chief  source  of  beauty. 
To  drain  the  surface  soil,  where  it  is 
supplied  by  water  from  the  subsoil,  re- 
quires some  knowledge  of  the  strata  of 
which  the  subsoil  is  composed.  In  gene- 
ral the  strata  composing  the  subsoil  lie 
over  one  another  in  a  direction  more  or 
less  approaching  to  horizontal ;  and  when 
the  natural  inclination  of  the  surface  is 
every  where  parallel  to  this  strata  be- 
neath, the  water,  if  it  oozes  out  of  the 
subsoil  at  all,  will  generally  do  so  equally 
throughout  the  subsoil;  and  in  such 
cases  numerous  drains  at  no  great  dis- 
tance are  required  to  carry  it  off,  pre- 
cisely as  in  the  case  of  draining  soils 
with  retentive  subsoils.  Bat  when  the 
line  of  surface  does  not  correspond  with 
the  line  of  substrata,  but  intersects  this 
line,  then  water  will  generally  be  found 


oozing  out  at  the  line  of  intersection, 
technically  called  the  cropping  out  of  the 
strata.  The  quantity  of  water  which  will 
issue  from  these  sections  or  cropping3 
out  of  broken  strata  will  depend  on  a 
great  variety  of  circumstances,  into  which 
it  is  unnecessary  here  to  enter ;  be- 
cause in  all  cases  the  mode  of  draining 
is  the  same,  viz.,  that  of  forming  a  drain 
parallel  to  the  line  of  fracture  of  the 
strata.  This  drain  in  some  cases  is  not 
required  to  extend  the  whole  length  of 
the  line  of  the  fracture ;  because  if  the 
strata  have  a  double  inclination,  so  as  it 
were  to  conduct  the  water  to  one  angle 
or  point,  a  drain  at  that  angle  or  point 
will  carry  off  the  whole  of  the  superflu- 
ous water  contained  in  the  strata.  The 
subsoil  in  some  cases  is  composed  of 
strata  in  a  nearly  vertical  position,  and 
in  others  of  strata  alternately  depressed 
and  elevated,  so  that  a  section  through 
them  would  form  a  serpentine  line  ;  and 
sometimes  the  subsoil  is  composed  of 
strata  the  layers  of  which  have  been 
broken  up  and  jumbled  together.  All 
these,  and  other  cases,  are  to  be  drained 
in  one  or  more  of  the  above  described 
modes  ;  that  is,  accumulated  water,  whe- 
ther in  the  soil  or  above  it,  is  to  be  let 
off  by  cuts  or  drains  made  at  the  lowest 
points  of  accumulation  ;  and  surface  soil 
saturated  with  water,  whether  from 
greater  atmospherical  supplies  than  can 
be  carried  off  by  evaporation  or  can  sink 
into  the  subsoil,  or  whether  it  arise  from 
sources  in  the  subsoil,  is  to  be  carried 
off  by  numerous  drains  close  to  one 
another,  and  the  tops  of  which  are  the 
cultivated  soil,  or  the  permanent  cloth- 
ing of  grass  or  other  herbage. 

Draining  is  not  required  in  this  coun- 
try as  much  as  in  England  ;  yet  in  very 
many  instances,  as  in  heavy  clay  soils 
and  "on  low  swamp  lands,  it  should  be 
the  first  step  in  the  cultivation  of  the 
land.  When  the  soil  is  porous,  light, 
and  sandy,  drains  are  not  required ;  or 
if  so,  need  only  be  placed  far  apart  and 
at  great  depth  (below  5  feet) :  on  clay 
lands  they  require  to  be  closer,  and  about 
the  depth  of  30  or  36  inches.  Draining 
tools  and  tiles  are  now  coming  into  much 
use ;  and  when  it  is  considered  that  it 
raises  the  produce  of  the  land  to  one 
third  more,  few  intelligent  farmers  nrho 
cultivate  well  will  neglect  it.  Pipe  drains 
are  better  for  general  use  than  arch 
drains  with  flat  soles,  as  the  water  is  de- 
livered quicker  in  its  channel,  and  the 
latter  is  kept  clean,  not  choking  up :  the 
latter,  however,  hold  better  in  clay  soils. 


136 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[dry 


The  top  of  every  drain  should  be  suf- 
ficiently far  below  the  surface  that  the 
plough  in  passing  over  will  not  touch  it. 

DRILL.  In  mechanics,  a  small  instru- 
ment of  steel  for  perforating  metals  or 
hard  substances.  Its  action  is  produced 
by  communicating  to  it  a  very  rapid  ro- 
tation by  means  of  a  drill-bow. 

Drill.  In  Agr.,  a  machine  for  sowing 
agricultural  seeds  in  rows  ;  sometimes 
worked  by  the  hand  alone,  and  some- 
times bv  the  addition  of  a  horse. 

DKILL  HUSBANDRY.  In  Agr.,  the 
cultivation  of  arable  land,  by  sowing  the 
crops  in  rows  ;  the  advantage  of  which 
is,  that  it  admits  of  destroying  the  weeds, 
and  stirring  the  soil  in  the  intervals  be- 
tween the  lines  of  plants.  As  this  mode 
of  cultivation  requires  some  implements 
and  machines  not  in  use  in  the  com- 
moner kinds  of  farming,  and  as  it  is  be- 
sides better  adapted  for  some  soils  than 
for  others,  it  is  not  so  generally  used  as 
the  obvious  advantages  attending  it  would 
lead  us  to  expect. 

DROSOMETER.  Any  instrument  for 
measuring  the  quantity  of  dew  that  col- 
lects on  the  surface  of  a  body  exposed 
to  the  open  air  during  the  night.  The 
first  instrument  for  this    purpose   was 

Eroposed  by  Weidler.  It  consisted  of  a 
ent  balance  which  marked  in  grains  the 
preponderance  which  a  piece  of  glass  of 
certain  dimensions,  laid  horizontally  in 
one  of  the  scales,  had  acquired  from  the 
settling  and  adhesion  of  the  globules  of 
moisture.  A  simpler  and  more  con- 
venient drosometer  would  be  formed  on 
the  principle  of  the  rain  gauge ;  and  in 
order  to  facilitate  the  descent  of  the  dew 
down  the  sides  of  the  funnel  into  the 
tube,  a  coat  of  delicate  salt  of  tartar  may 
be  spread  over  the  shallow  surface.  Dr. 
Wells,  in  making  his  celebrated  experi- 
ments on  dew,  exposed  a  small  quantity 
of  wool  to  the  open  sky,  and  the  differ- 
ence in  its  weight  when  laid  down  and 
taken  up  showed  the  quantity  of  mois- 
ture it  had  imbibed  in  the  interval. 

DRUGGET.  A  coarse  and  flimsy 
woollen  texture,  chiefly  used  for  covering 
carpets.  It  was  formerly  extensively 
employed  as  an  article  of  clothing  by  the 
poorer  classes,  more  especially  of  fe- 
males ;  but  this  and  similar  fabrics  are 
now  almost  wholly  superseded  by  cotton 
goods,  which  induce  greater  cleanliness, 
and  are  less  liable  to  retain  infectious  and 
contagious  poisons. 

DRY  DISTILLATION.  This  term  is 
applied  to  the  distillation  of  substances 
per  se,  or  without  the  addition  of  water : 


thus  if  we  put  wood  into  a  retort  or  other 
distillatory  apparatus,  and  subject  it  to 
heat,  it  yields  tar,  vinegar,  water,  and 
various  gaseous  and  other  matters,  which 
are  called  the  products  of  its  dry  or  de- 
structive distillation. 

DRYING  OIL.  This  term  is  generally 
applied  to  linseed  and  other  ofls  which 
have  been  heated  with  oxide  of  lead: 
they  are  the  bases  of  many  paints  and 
varnishes. 

DRY  ROT.  A  disease  which  attacks 
wood,  rendering  it  brittle,  and  destroy- 
ing the  cohesion  of  its  parts,  is  known 
by  thisname.  It  occurs  among  the  tim- 
bers of  ships,  where  it  sometimes  com- 
mits the  most  serious  damage,'  jnd  in 
damp  ill-ventilated  houses.  It  is  usually 
ascribed  to  the  attacks  of  fungi,  espe- 
cially to  such  as  Poly-porm  destructor 
and  Merulius  lachrymans,  whose  filamen- 
tous spawn  or  thallus  appears  upon  the 
surface,  overspreading  it  like  a  tough 
thick  skin  of  white  leather ;  and  there  is 
no  doubt  of  its  being  often  connected  with 
appearance  of  such  fungi.  But  dry  rot 
is  certainly,  in  some  cases,  to  be  identi- 
fied with  the  presence  of  a  fungi  of  a 
more  simple  kind  than  those  just  men- 
tioned ;  especially  of  such  as  belong  to 
or  resemble  the  genus  Sporotrichum. 

The  destruction  of  timber  by  such 
plants  is  effected  in  part  by  the  disin- 
tegration of  the  tubes  of  the  weed,  in 
consequence  of  the  introduction  between 
them  of  the  fine  filamentous  spawn  of 
the  fungi,  and  in  part  by  the  dampness 
which  is  thus  conveyed  to  the  interior 
of  the  wood,  where  it  soon  produces  de- 
composition. It  is  not,  however,  certain 
that  dry  rot  is  always  caused  in  this 
manner ;  on  the  contrary,  the  term  ap- 
pears to  be  frequently  applied  to  cases  of 
spontaneous  decomposition  of  timber 
without  the  presence  of  fungi,  or  when 
the  appearance  of  the  latter  takes  place 
long  after  the  commencement  of  the  dis- 
ease. 

When  dry  rot  produced  by  fungi  has 
once  made  its  appearance,  there  is  no 
means  of  arresting  its  progress  without 
removing  the  whole  of  the  diseased  and 
neighboring  parts ;  and  even  then  it  will 
probably  again  break  out,  unless  means 
can  be  taken  to  introduce  a  circulation 
of  fresh  air  among  the  parts  liable  to  the 
affection.  For  if  timber  is  allowed  to 
remain  in  a  damp  situation,  and  in  the 
dark,  it  affords  so  favorable  a  nidus  foi 
the  seeds  of  fungi,  that  they  are  almost 
certain  to  vegetate  upon  it ;  unless  some 
means  have  been   previously  taken  to 


ouc] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


137 


render  the  timber  permanently  unsuited 
to  their  growth.  This  end  appears  to 
have  been  attained  by  Mr.  Kyan,  who 
obtained  a  patent  for  pickling  timber, 
as  a  preventive  of  the  dry  rot,  and  who 
employed  for  this  purpose  a  solution  of 
corrosive  sublimate.  This  salt  of  mer- 
cury is  a  well-known  vegetable  poison : 
if  any  animal  jelly,  upon  which  fungi  will 
quickly  appear  in  the  form  of  mouldi- 
ness,  is  mixed  with  a  minute  quantity  of 
corrosive  sublimate,  no  fungi  will  in  that 
case  be  produced ;  so  that  both  theory 
and  experience  are  in  favor  of  Mr.  Ev- 
an's process.  It  is  not  improbable  that 
the  progress  of  dry  rot  might  even  be 
arrested  in  the  buildings  where  it  occurs, 
if  the  timbers  could  be  got  at  and  well 
washed  with  the  same  solution. 

Although  dry  rot  generally  fixes  itself 
upon  timber,  it  will  also  attack  any  form 
of  vegetable  matter.  The  paper  hang- 
ings of  rooms,  chiefly  composed  of  cot- 
ton and  linen  thread,  are  occasionally 
overrun  in  houses  which  have  been  long 
shut  up  and  neglected ;  and  the  mildew 
which  destroys  the  strength  of  canvas  is 
only  another"  form  of  dry  rot,  the  ap- 
pearance of  which  is  altered  by  the  special 
circumstances  under  which  the  fungus  is 
developed,  or  by  the  species  of  the  fun- 
gus itself.    (See  Wood,  Preservation  of.) 

DRYSALTER.  A  dealer  in  salted  or 
dried  meats,  and  in  the  materials  used  in 
pickling,  salting,  and  preserving  various 
kinds  of  food  ;  hence  drysalters  usually 
sell  a  number  of  saline  substances  and 
miscellaneous  drugs. 

DRYSTOVE.  A  glazed  structure  for 
containing  the  plants  of  dry  arid  cli- 
mates ;  such  as  the  cactuses,  mesembry- 
anthemums,  aloes,  and  other  succulents 
of  Africa. 

DUCTILITY.  A  property  of  certain 
bodies,  in  consequence  of  which  they 
can  be  drawn  out  at  length  without  suf- 
fering any  interruption  of  the  continuity 
of  their  constituent  particles.  The  term 
ductility  is  frequently  confounded  with 
malleability,  or  that  'property  of  bodies 
through  which  different  forms  can  be 
given  to  them  by  pressure  or  percussion. 
In  general  ductility  depends,  in  a  greater 
or  less  degree,  on  the  temperature.  Some 
bodies — wax  for  example — are  rendered 
ductile  by  a  small  degree  of  heat ;  while 
glass  requires  a  violent  heat  before  it 
acquires  ductility.  Some  of  the  metals 
— for  example,  gold,  silver,  lead,  &c. — 
are  ductile  under  all  kno;vn  tempera- 
tures. 

"  The  ductility  of  some  metals  far  ex- 


ceeds that  of  any  other  substance.  The 
goldbeaters  beerin  their  operations  with  a 
riband  an  inch  broad  and  150  inches 
long,  which  had  been  reduced,  by  passing 
it  through  rollers,  to  about  the  800th 
part  of  an  inch  in  thickness.  The  riband 
is  cut  into  squares,  which  are  disposed 
between  leaves  of  vellum,  and  beat  by  a 
heavy  hammer  till  they  acquire  a  breadth 
of  about  three  inches,  and  are  thus  ex- 
tended to  ten  times  their  former  sur- 
face. These  are  again  quartered  and 
placed  between  the  folds  of  goldbeater's 
skin,  and  stretched  out  by  the  operation 
of  a  lighter  hammer  to  the  breadth  of 
five  inches.  The  same  process  is  re- 
peated, sometimes  more  than  once,  by  a 
succession  of  lighter  hammers ;  so  that 
376  grains  of  gold  are  thus  finally  ex- 
tended into  2000  leaves  of  3-3  inches 
square,  making  in  all  80  books,  contain- 
ing each  of  them  25  leaves.  The  metal  is 
consequently  reduced  to  the  thinness  of 
the  282,000th  part  of  an  inch,  and  every 
leaf  weighs  rather  less  ■  than  the  fifth 
part  of  a  grain.  A  particle  of  gold,  not 
exceeding  the  500,000th  part  of  a  grain, 
is  hence  distinctly  visible  to  the  naked 
eye. 

"It  has  been  asserted  that  wires  of 
pure  gold  can  be  drawn  of  only  the  4000th 
part  of  an  inch  in  diameter ;  but  Dr. 
Wollaston,  by  an  ingenious  procedure, 
has  lately  advanced  much  farther.  Tak- 
ing a  short  cylinder  of  silver,  about  the 
third  part  of  an  inch  in  diameter,  he 
drilled  a  fine  hole  through  its  axis,  and 
inserted  a  wire  of  platinum  only  the 
100th  part  of  an  inch  thick.  This  silver 
mould  was  now  drawn  through  the  suc- 
cessive holes  of  a  steel  plate,  till  its  di- 
ameter was  brought  to  near  the  1500th 
part  of  an  inch ;  and  consequently  the 
internal  wire,  being  diminished  in  the 
same  proportion,  was  reduced  to  between 
the  4000th  and  5000th  part  of  an  inch. 
The  compound  wire  was  then  dipped  in 
warm  nitric  acid,  which  dissolved  the 
silver,  and  left  untouched  its  core,  or  the 
wire  of  platinum.  By  passing  the  in- 
crusted  platinum  through  a  greater  num- 
ber of  holes  wires  still  finer  were  ob- 
tained, some  of  them  only  the  30,000th 
part  of  an  inch  in  diameter.  The  te- 
nacity of  the  metal,  before  reaching  this 
limit,  was  even  considerable ;  a  platinum 
wire,  of  the  18,000th  part  of  an  inch  in 
diameter,  supporting  the  weight  of  a 
grain  and  a  third." 

Glass,  when  well  softened  by  the  fire, 
becomes  as  ductile  as  soft  wax,  and  may 
be  spun  out  into  threads  of  greater  fine- 


138 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[i 


ness  than  any  hair,  and  which  bend  and 
wave  like  hair  in  the  wind.  The  method 
of  producing  these  threads  is  exceedingly 
easy.  Two  workmen  are  employed  ;  the 
first  holds  the  glass  over  the  flame  of  a 
lamp ;  the  second  applies  a  hook  to  the 
metal  in  fusion,  which,  when  drawn 
back,  brings  with  it  a  thread  of  glass, 
still  adhering  to  the  mass ;  the  hook  is 
then  fitted  on  the  circumference  of  a 
wheel,  which,  being  turned  round,  draws 
out  the  thread,  and  winds  it  about  its 
rim.  Some  of  these  threads  are  scarcely 
larger  than  that  of  a  silkworm,  and  are 
surprisingly  flexible. 

DUNGING.  One  of  the  processes  of 
dyeing  and  calico  printing.  The  steeping 
the  goods  in  a  bath  of  cowdung. 

Experience  has  proved  that  dunging  is 
one  of  the  most  important  steps  in  the 
process  of  calico  printing,  and  that  if  it 
be  not  well  performed  the  dyeing  is  good 
for  nothing.  Before  we  can  assign  its 
peculiar  function  to  the  dung  in  this 
case,  we  must  know  its  composition. 
Fresh  cows'  dung  is  commonly  neutral 
when  tested  by  litmus  paper  ;  but  some- 
times it  is  slightly  alkaline,  owing,  proba- 
bly, to  some  peculiarity  in  the  food  of 
the  animal. 

The  total  constituents  of  100  parts  of 
cow  dung  are  as  follows:  Water,  69-58; 
bitter  matter,  0*74;  sweet  substance, 
0-93  ;  chlorophylle,  0-28  ;  albumine,  0-63; 
muriate  of  soda,  0*08 ;  sulphate  of  pot- 
ash, 0*05 ;  sulphate  of  lime,  0-25 ;  car- 
bonate of  lime,  0*24;  phosphate  of  lime, 
0-46 ;  carbonate  of  iron,  0*09 ;  woody 
fibre,  26-39;  silica,  1-14:  loss,  0-14. 

In  dunging  calicoes  the  excess  of  un- 
combined  mordant  is  in  part  attracted  by 
the.  soluble  matters  of  tne  cow's  dung, 
and  forms  an  insoluble  precipitate,  which 
has  no  affinity  fur  the  cloth,  especially  in 
presence  of  the  insoluble  part  of  the  dung, 
which  strongly  attracts  alumina.  The 
most  important  part  which  that  insoluble 
matter  plays,  is  to  seize  the  excess  of  the 
mordants,  in  proportion  as  they  are  dis- 
solved by  the  water  of  the  bath,  and  thus 
to  render  their  reaction  upon  the  cloth 
impossible.  It  is  only  in  the  deposite, 
therefore,  that  the  matters  carried  off 
from  the  cloth  by  the  dung  are  to  be 
found. 

M.  Camille  Kcechlin  ascribes  the  action 
of  cow  dung  chiefly  to  its  albuminous 
constituents  combining  with  the  alumina 
and  iron,  of  the  acetates  of  these  bases 
dissolved  by  the  hot  water  of  the  bath. 
The  acids  consequently  set  free,  soon  be- 
come evident  by  the  test  of  litmus  paper, 


I  after  a  few  pieces  are  passed  through, 
and  require  to  be  got  rid  of  either  by  a 
fresh  bath,  or  by  adding  chalk  to  the  old 
one.  The  dung  thus  serves  also  to  fix 
the  bases  on  the  cloth,  when  used  in 
moderation.  It  exercises  likewise  a  dis- 
oxydating  power  on  the  iron  mordant, 
and  restores  it  to  a  state  more  fit  to  com- 
bine with  coloring  matter. 

DWARFING  TREES.  Dwarf  trees 
may  be  produced  in  three  different  ways : 
by  grafting  on  dwarf  slow-growing  stocks, 
as,  for  example,  the  pear  on  the  quince  • 
by  planting  in  pots  of  small  size  filled 
with  poor  soil,  by  which  the  plant  is 
starved  and  stunted;  and  by  causing  a 
portion  of  the  extremity  of  a  branch  to 
produce  roots,  and  then  cutting  it  off  and 
planting  it  in  a  pot  or  box  of  poor  soil. 
This  last  is  the  Chinese  method,  and  is 
thus  performed: — The  extremity  of  a 
branch  two  or  three  feet  in  length,  in  a 
fruit  or  flower-bearing  state — for  exam- 
ple, the  points  of  the  branches  of  a  fir 
tree  bearing  cones,  or  of  an  elm  bearing 
blossom  buds — being  fixed  on,  a  ring  of 
bark  is  taken  off  at  the  point  where  it  is 
desired  that  the  roots  should  be  pro- 
duced. The  space  thus  laid  bare  is  co- 
vered with  a  ball  of  moist  clay,  which  is 
kept  moist  by  being  covered  with  moss, 
which  is  occasionally  watered.  In  the 
course  of  two  or  three  months  in  some 
trees,  and  of  a  year  or  two  in  others, 
roots  are  protruded  into  the  ball  of  clay. 
The  branch  may  then  be  cut  off  below 
the  part  from  whence  the  roots  have 
been  protruded,  and  the  branch  being 
]  ilanted  in  a  pot  of  poor  soil,  and  kept 
pparingly  supplied  with  water,  it  will  re- 
main nearly  in  its  present  state  for  many 
years ;  producing  leaves,  and  perhaps 
flowers,  annually,  but  never  shoots  longer 
than  a  few  lines. 

DYEING.  The  object  of  this  beauti- 
ful art  is  to  fix  certain  coloring  matters 
uniformly  and  permanently  in  the  fibres 
of  wool,  silk,  linen,  cotton,  and  other 
substances.  The  moderns  have  obtained 
from  this  Continent  several  dye-drusrs 
unknown  to  the  ancients  ;  such  as  cochi- 
neal, quercitron,  Brazil  wood,  logwood, 
annatto;  and  they  have  discovered  the 
art  of  using  indigo  as  a  dj-e,  which  the 
Romans  knew  only  as  a  pigment.  But 
the  vast  superiority  of  our  dyes  over 
those  of  former  times  must  be  ascribed 
principally  to  the  employment  of  pure 
alum  and  solution  of  tin  as  mordants, 
either  alone  or  mixed  with  other  bases  ; 
substances  which  give  to  our  common 
dye-stuffs  remarkable  depth,  durability, 


dye] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


139 


and  lustre.  Another  improvement  in 
dyeing  of  more  recent  date  is  the  appli- 
cation to  textile  substances  of  metallic 
compounds,  such  as  Prussian  blue, 
chrome  yellow,  manganese  brown,  &c. 

There  are  a  few  dyeing  materials  which 
impart  their  color  to  different  stuffs  with- 
out any  previous  preparation,  and  these 
have  been  technically  termed  substantive 
colors ;  by  far  the  greater  number,  how- 
ever, of  coloring  materials,  only  impart  a 
fugitive  tint  under  such  circumstances, 
ami  require  that  the  stuff  to  be   dyed 
should  undergo  some  previous  prepara- 
tion, in  order  to  render  the  color  perma- 
nent ;  that  is,  capable  of  resisting  the  ac- 
tion of  air,  light,  and  water.    The  sub- 
stance applied  with  this  intention  is  called 
a  base  or  mordant,  and  must  possess  an 
affinity  for  the  fibre  of  the  stuff  on  the 
one  hand,  and  for  the  coloring  materials 
on  the  other.    The  mordant  often  effects 
another  important  object;  that  of  chang- 
ing or  exalting  the  color  at  the  same  time 
that  it  fixes  it.     The  principal  mordants 
are  aluminous  earth  and  oxide  of  iron, 
and  these  are  usually  applied  in  the  state 
of  acetates.     Oxide  of  tin  is  a  valuable 
mordant ;   it  is  generally  applied  as  ni- 
trate or  chloride.  .As   an  instance,   we 
may  mention  the  mode  of  dyeing  calico 
red  by  means  of  madder,  a  decoction  of 
which,    if  applied    to    the    unprepared 
goods,  would  only  give  them  a  dirty  red 
tinge,  neither  agreeable  nor  permanent. 
If  the  calico  be  previously  passed  through 
a  weak  solution  of  acetate  of  alumina, 
and  then  dried  at  a  high  temperature, 
and  afterwards  washed,  a  portion  of  the 
alumina  is  retained  in  chemical  combina- 
tion with  the  fibre  of  the  calico ;   and 
when  thus  prepared  and  submitted  to  the 
action  of  a  hot  decoction  of  madder,  and 
again  washed,  it  comes  out  of  a  fine  red, 
which  is  fixed  in  consequence  of  the  at- 
traction of  the  alumina  for  the  peculiar 
principle  which  gives  color  to  the  mad- 
der.    If  the  mordant  be  oxide  of  iron  in- 
stead of  alumina,  the  color  which  is  then 
produced  is  purple  •  and  various  shades 
and  colors  are  obtained  by  mixing  mor- 
dants, by  using  more  or*  less  of  them, 
and  by  applying  the  colored  solutions  in 
various  states  of  concentration.    Some- 
times articles  are  dyed  by  a  similar  pre- 
cipitation of  colored  metallic  oxides  in 
the  fibre ;    thus  yellow  is  obtained  by 
passing  cloth  impregnated  with  acetate 
of  lead  through  a  solution  of  chromate  of 
potash  :  a  double  decomposition  ensues, 
and  yellow  chromate  of  lead  is  precipi- 
tated in  and  combined  with  the  vegetable 


or  animal  fibre.  Blues  are  produced  by 
passing  the  goods  previously  mordanted 
with  iron  through  an  acidulated  solution 
of  ferrocyanate  of  potash  ;  these  are  gene- 
rally called  chemical  colors,  though  not  in 
fact  more  so  than  the  others.  Scarlet  is 
exclusively  produced  by  the  coloring 
matter  either  of  the  cochineal  or  of  the 
lac  insect,  which  is  fixed  by  oxide  of 
tin,  or  by  alumina,  and  heightened  by  the 
action  of  tartar. 

Indigo.  This  dye-drug,  when  tolera- 
bly good,  contains  half  its  weight  of  in- 
digotine.  The  cold  vat  is  prepared  com- 
monly with  water,  copperas,  indigo,  lime, 
or  sometimes  carbonate  of  soda,  and  is 
used  almost  exclusively  for  cotton  and 
linen ;  immersion  in  acidulated  water  is 
occasionally  had  recourse  to  for  removing 
a  little  oxyde  of  iron  which  attaches  it- 
self to  the  cloth  dyed  in  this  vat. 

The  indigo  vat  for  wool  and  silk  is 
mounted  exclusively  with  indigo,  good 
potashes  of  commerce,  madder,  and  bran. 
In  this  vat,  the  immediate  principles  with 
base  of  carbon  and  hydrogen,  such  as  the 
extracts  of  madder  and  bran,  perform  the 
disoxydising  function  of  the  copperas  in 
the  cold  vat.  The  pastel  vats  require 
most  skill  and  experience,  in  consequence 
of  their  complexity.  The  greatest  diffi- 
culty occurs  in  keeping  them  in  a  good 
condition,  because  they  vary  progressive- 
ly as  the  dyeing  goes  on,  by  the  abstrac- 
tion of  the  indigotine,  and  the  modifica- 
tion of  the  fermentable  matter  employed 
to  disoxygenate  the  indigo.  The  alkaline 
matter  also  changes  by  the  action  of  the 
air.  By  the  successive  additions  of  indi- 
go, alkali,  &c,  this  vat  becomes  very 
difficult  to  manage  with  profit  and  suc- 
cess. The  great  affair  of  the  dyer  is  the 
proper  addition  of  lime ;  too  much  or  too 
little  being  equally  injurious. 

Sulphate  of  indigo,  or  Saxon  blue,  is 
used  also  to  dye  silk  and  wool.  If  the 
wools  be  ill  sorted,  it  will  show  their  dif- 
ferences by  the  inequalities  of  the  dye. 
Wool  dyed  in  this  bath  put  into  water 
saturated  with  sulphureted  hydrogen,  be- 
comes soon  colorless,  owing  to  the  disox- 
ygenation  of  the  indigo.  The  woollen  cloth 
when  exposed  to  the  air  for  some  time 
resumes  its  blue  color,  but  not  so  intense- 
ly as  before. 

Logwood.  The  properties  of  hema- 
tine  explain  the  mode  of  using  logwood. 
When  stuffs  are  dyed  in  the  infusion  or 
decoction  of  this  wood,  under  the  influ- 
ence of  a  base  which  acts  upon  the  hema- 
tine  in  the  manner  of  an  alkali,  a  blue 
dye,  bordering  upon  violet,  is  obtained. 


140 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[dye 


Such  is  the  process  for  dyeing  cotton  and 
wool  a  logwood  blue  by  means  of  verdi- 
gris, crystallized  acetate  of  copper,  and 
acetate  of  alumina. 

When  we  dye  a  stuff  yellow,  red,  or 
orange,  we  have  always  bright  tints  :  with 
blue,  we  may  have  a  very  dark  shade, 
but  somewhat  violet;  the  proper  black 
can  be  obtained  only  by  using  the  three 
colors,  blue,  red,  and  yellow  in  proper 
proportions.  Hence  we  can  explain  how 
the  tints  of  yellow,  red,  orange,  blue, 
green,  and  violet,  may  be  browned,  by 
applying  to  them  one  or  two  colors  which 
along  with  themselves  would  produce 
black  ;  and  also  we  may  explain  the  na- 
ture of  that  variety  of  blacks  and  grays 
which  seems  to  be  'indefinite.  Nutgails 
and  sulphate  of  iron,  so  frequently  em- 
ployed for  the  black  dye,  give  only  a  vio- 
let or  bluish  gray.  The  pyrolignite  of 
iron,  which  contains  a  brown  empyreu- 
matic  matter,  gives  to  stuffs  a  brown  tint, 
bordering  upon  greenish  yellow  in  the 
pale  hues,  and  to  chestnut  brown  in  the 
dark  ones.  By  galling  cotton  and  silk,  and 
giving  them  a  bath  of  pyrolignite  of  iron, 
we  may,  after  some  alternations,  dye 
them  black.  Galls,  logwood,  and  a  salt 
of  iron,  produce  merely  a  very  deep  vio- 
let blue  ;  but  by  boiling  and  exposure  to 
the  air,  the  hematate  of  iron  is  changed, 
becoming  red-brown,  and  favors  the  pro- 
duction of  black.  Galls  and  salts  of  cop- 
per dye  stuffs  an  olive  drab,  logwood 
and  salts  of  copper,  a  violet  blue  ;  hence 
their  combination  should  produce  a 
black.  In  using:  sumach  as  a  substitute 
for  galls,  we  should  take  into  account 
the  proportion  of  yellow  matter  it  con- 
tains. When  the  best  possible  black  is 
wanted  upon  wool,  we  must  give  the 
stuff  a  foundation  of  indigo,  then  pass  it 
it  into  a  bath  of  logwood,  sumach,  and 
proto-sulphate  of  iron.  The  sumach 
may  be  replaced  by  one  third  of  its 
weight  of  nutgails. 

The  compound  or  mixed  colors,  are 
such  as  result  from  the  combination  of 
two  differently  colored  dye-stuffs,  or  from 
dyeing  stuffs  with  one  color,  and  then 
with  another.  The  simple  colors  of  the 
dyer  are  red,  yellow,  blue,  and  black, 
with  which,  when  skillfully  blended,  he 
can  produce  every  variety  of  tint.  Ber- 
haps  the  dun  or  fawn  color  might  be  ad- 
ded to  the  above,  as  it  is  directly  ob- 
tained from  a  great  many  vegetable  sub- 
stances. 

1.  Bed  with  yellow,  produces  orange; 
a  color  which,  upon  wool,  is  given  usual- 
ly with  the  spent  scarlet  bath.    To  this 


shade  may  be  referred  flame  color,  pome- 
granate, capuchin,  prawn,  jonquil,  cassis, 
chamois,  cafe  au  lait,  aurora,  marigold, 
orange  peel,  mordores,  cinnamon,  gold 
&c.  Snuff,  chestnut,  musk,  and  other 
shades  are  produced  by  substituting  wal- 
nut peels  or  sumach  for  bright  yellow. 
If  a  little  blue  be  added  to  orange,  an 
olive  is  obtained.  The  only  direct  orange 
dyes  are  annotto,  and  subchromate  of 
lead  (see  Silk  and  "Wool  Dyeing). 

2.  Bed  with  blue  produces  purple,  vio- 
let, lilac,  pigeon's  neck,  mallow,  peach- 
blossom,  bleu  de  roi,  lint-blossom,  ama- 
ranth. 

3.  Bed  with  black;  brown,  chocolate, 
marone,  &c. 

4.  Yellow  with  blue ;  green  of  a  great 
variety  of  shades,  such  as  nascent  green, 
gay  green,  grass  green,  spring  green, 
laurel  green,  sea  green,  celadon  green, 

Sarrot  green,  cabbage  green,  apple  green, 
uck  green. 

5.  Mixtures  of  colors,  three  and  three, 
and  four  and  four,  produce  an  indefinite 
diversity  of  tints ;  thus,  red,  yellow,  and 
blue,  form  brown  olives,  and  greenish 
grays ;  in  which  the  blue  dye  ought  al- 
ways to  be  first  given,  lest  the  indigo  vat 
should  be  soiled  by  other  colors.  Bed, 
yellow,  and  gray,  (which  is  a  gradation 
of  black),  give  the  dead-leaf  tint,  as  well 
as  dark  orange,  snuff  color,  &c.  Bed, 
blue,  and  gray,  give  a  vast  variety  of 
shades  ;  as  lead  gray,  slate  gray,  wood- 
pigeon  gray,  and  other  colors,  too  nume- 
rous to  specify. 

The  following  list  of  dyes,  and  the  co- 
loring substances  which  produce  them, 
may  prove  useful. 

Bed.  Cochineal,  kermes,  lac,  madder, 
archil,  carthamus  or  safiiower,  Brazil 
wood,  logwood,  periodide  of  mercury, 
alkanet. 

Yellow.  Quercitron,  weld,  fustic,  (yel- 
low wood)  annotto,  sawwort,  dyer's 
broom,  turmeric,  fustic,  {rhus  cotlnus) 
Persian  and  Avignon  berries,  (rTiamnus 
infectorius)  willow,  peroxide  of  iron ; 
cliromate  of  lead,  (chrome  yellow)  sul- 
phuret  of  arsenic,  hydrosulphuret  of  an- 
timony ;  nitric  acid  on  silk. 

Blue.  Indigo,  woad  or  pastel,  Prus- 
sian blue,  turnsole  or  litmus,  logwood 
with  a  salt  of  copper. 

Blade.  Galls,  sumach,  logwood,  wal- 
nut peels,  and  other  vegetables  which 
contain  tannin  and  gallic  acid,  along  with 
ferruginous  mordants.  The  anacardi- 
um  of  India. 

Green.  These  are  produced  by  tho 
blue  and  yellow  dyes  skillfully  combined ; 


ear] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


141 


with  the  exception  of  the  chrome  green, 
and  perhaps  the  copper  green  of  Schwein- 
furt. 

Orange.  Annotto,  and  mixtures  of 
red  and  yellow  dyes;  subchromate  of 
lead. 

Fawn,  Dun,  Hoot.  Walnut  peels,  su- 
mach, birch-tree,  henna,  sandal  wood. 

The  chemical  principles  of  the  art  of 
calico  printing  are  the  same  as  those  of 
dyeing,  but  the  details  are  more  difficult 
and  complicated  ;  and  in  consequence  of 
the  combination  of  a  great  variety  of  co- 
lors upon  the  same  ground,  the  process 
is  sometimes  extremely  refined  and  intri- 
cate ;  so  that  a  rich,  varied,  and  pleasing 
pattern,  thus  effectively  produced,  may 
be  considered  as  a  triumph  of  practical 
skill  over  theoretical  difficulties,  which  is 
scarcely  rivalled,  and  certainly  not.  ex- 
celled, *in  any  other  of  the  arts.  It  is  ob- 
vious that  calico  printing  is  in  the  abstract 
a  topical  dyeing  ;  and  much  discrimina- 
tion and  taste  are  requisite  in  the  con- 
trivance of  the  pattern,  its  general  de- 
sign, and  the  colors  in  which  it  is  exhib- 
ited. In  this  art  the  mordant^,  and 
sometimes  the  colors,  are  applied  either 
by  blocks,  upon  which  the  pattern  is  de- 
signed in  relief,  or  by  copperplates,  which 
are  engraved,  or  by  cylinders  or  rollers. 
If  the  aluminous  mordant  be  printed  by 
one  block  and  the  iron  mordant  by  ano- 
ther, and  the  mixture  of  the  two  by  a 
third,  and  the  piece  thus  prepared  be 
then  passed  through  a  madder  bath,  and 
properly  cleansed  and  bleached,  the  color 
will  only  adhere  to  the  mordanted  places, 
and  it  will  be  red  where  the  aluminous 
earth  only  has  been  applied,  purple  with 
the  mixed  mordant,  and  black  with  the 
iron  ;  if  the  same  three  mordants  be  used 
with  a  decoction  of  quercitron  bark,  the 
resulting  colors  will  be  yellow,  olive,  and 
brown ;  and  in  this  way  a  great  variety 
of  colors  may  be  produced.  Sometimes 
copperplate  and  block  printing  are  com- 
bined ;  a  fine  running  pattern  being 
printed  by  the  plate  or  cylinder  over  the 
whole  surface,  which  serves  as  a  ground 
work,  and  upon  which  other  figures  are 
printed  by  blocks.  Sometimes  the  mor- 
dant and  color  are  both  applied  at  once 
by  means  of  a  block,  and  rendered  fixed 
and  permanent  by  exposing  the  goods 
for  some  time  to  steam.  Beautiful  effects 
are  produced  by  printing  the  patterns  on 
a  mordanted  ground  with  some  substance 
which  will  resist  the  color,  and  so  pro- 
duce a  white  pattern  on  a  colored  ground. 
(See  Calico  Pkentlng.) 

DYKE.    In  geology  is  a  term  applied 


.  to  a  mass  of  igneous  rock,  as  granite, 
trap,  greenstone,  or  lava,  which  is  thrown 
up  or  injected  through  and  into  the  rents 
and  fissures  of  a  stratified,  or  even  an  ig- 
neous rock.  Dykes  are  of  frequent  oc- 
currence in  districts  where  primary  rock 
prevails.  Dyke  is  also  a  mound  of  earth 
or  stone,  or  other  material  intended  to 
prevent  the  sea  inundating  contiguous 
low  coasts,  such  as  in  Holland. 

DYNAMOMETEK.  An  instrument 
for  measuring  power  of  any  kind,  as  the 
strength  of  men  and  animals,  the  force  of 
machinery,  the  magnifying  power  of  a  te- 
lescope, &c.  An  instrument  for  measur- 
ing animal  force  was  invented  by  Mr. 
Graham  many  years  ago,  and  afterwards 
improved  by  Desaguliers ;  but  as  it  con- 
sisted of  wooden  works,  it  was  too  heavy 
and  bulky  to  be  conveniently  used  for 
ordinary  purposes.  Leroy,  of  the  Aca- 
demy of  Sciences  of  Paris,  proposed  a 
dynamometer,  which  consisted  merely  of 
a  tube  of  metal  of  ten  or  twelve  inches  in 
length,  placed  vertically  on  a  stand,  an^ 
containing  a  spring  in  its  interior,  which 
indicated  by  its  compression  the  amount 
of  the  force  applied.  The  instrument 
was  in  fact  the  same  in  principle  as  the 
common  spring  balance. 

The  most  convenient  dynamometer  is 
that  of  Regnier,  which  is  described  in  the 
Journal  de  VEcole  Polyteclinique.  It  con- 
sists of  an  elliptical  steel  spring  of  about 
12  inches  in  circumference,  and  the  force 
is  applied  either  by  pressing  the  two  ver- 
tices of  the  axis  minor  against  each  other, 
or  by  drawing  in  opposite  directions  the 
two  ends  of  the  axis  major.  In  both 
cases  the  sides  of  the  spring  are  made  to 
approach  each  other ;  and.  thus  they 
move  an  index  which  marks  the  degree 
of  approximation  on  a  semicircular  scale. 
By  means  of  this  machine  the  mean  force 
is  ascertained  which  a  man  can  exert  with 
the  right  hand,  or  with  the  left,  or  with 
both  together,  and  in  various  positions 
of  his  body.  Some  interesting  results  re- 
lating to  the  average  strength  of  men  at 
different  ages,  and  of  different  weights 
and  sizes,  have  been  deduced  by  M. 
Quetelet  of  Brussels,  from  numerous  ex- 
periments with  his  dynamometer.  In 
testing  the  value  of  ploughs,  the  dynam- 
ometer should  be  used,  instead  of  plough- 
ing a  sriven  space  of  land. 

EARTHEN  WAEE.    See  Pottery. 

EARTH.  Modern  science  has  demon- 
strated that  the  substances  called  primi- 
tive earths,  and  which  prior  to  the  great 
electro-chemical  career  of  Sir  H.  Davy, 
I  were  deemed  to  be  elementary  matter, 


142 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


EBU 


are  all  compounds  of  certain  metallic  ba- 
ses and  oxygen,  with  the  exception  of 
silica,  whose  base,  silicon,  being  analo- 
gous to  boron,  has  led  that  compound  to 
be  regarded  as  an  acid ;  a  title  character- 
istic of  the  part  it  extensively  performs 
in  neutralizing  alkaline  bodies,  in  mine- 
ral nature,  and  in  the  processes  of  art. 
Four  of  the  earths,  when  pure,  possess 
decided  alkaline  properties,  being  more 
or  less  soluble  in  water;  having  (at  least 
three  of  them)  an  acrid  alkaline  taste, 
changing  the  purple  infusion  of  red  cab- 
bage to  green,  most  readily  saturating  the 
acids,  and  affording  thereby  neutro-saline 
crystals.  These  four  are  baryta,  strontia, 
lime,  and  magnesia.  The  earths  proper 
are  five  in  number  ;  alumina,  glucina, 
yttria,  zirconia,  and  thorina:  These  do 
not  change  the  color  of  infusion  of  cab- 
bage or  tincture  of  litmus,  do  not  readily 
neutralize  acidity,  and  are  quite  insolu- 
ble in  water.  The  alkalis  are  soluble  in 
water,  even  when  carbonated  ;  a  property 
which  distinguishes  them  from  the  alka- 
line earths.  Lithia  must  for  this  reason 
be  considered  to  be  an  alkali.  See  the 
above  substances  in  their  alphabetical 
places. 

EAU  DE  COLOGNE.  This  prepara- 
tion has  long  possessed  great  celebrity, 
in  consequence  chiefly  of  the  numerous 
virtues  ascribed  to  it  by  its  venders  ;  and 
is  resorted  to  by  many  votaries  of  fashion 
as  a  panacea  against  ailments  of  every 
kind.  It  is  however  nothing  more  than 
aromatized  alcohol,  and  as  such,  an  agreea- 
ble companion  of  the  toilet.  Numerous 
fictitious  receipts  have  been  offered  for 
preparing  eau  de  Cologne ;  the  following 
may  be  reckoned  authentic,  bavins:  been 
imparted  by  Farina  himself  to  a  friend. 

Take  60  gallons  of  silent  brandy  ;  sage, 
and  thyme,  each  6  drachms  ;  balm-mint 
and  spearmint,  each  12  ounces  ;  calamus 
aromaticus,  4  drachms  ;  root  of  angelica, 
2  drachms  •  camphor,  1  drachm  ;  petals 
of  roses  and  violets,  each  4  ounces ;  flow- 
ers of  lavender,  2  ounces ;  flowers  of 
orange,  4  drachms  ;  wormwood,  1  ounce ; 
nutmegs,  cloves,  cassia  lignia,  mace,  each 
4  drachms.  Two  oranges  and  two  lemons, 
cut  in  pieces.  Allow  the  whole  to  mace- 
erate  in  the  spirit  during  24  hours,  then 
distil  off  40  gallons  by  the  heat  of  a 
water  bath.     Add  to  the  product : 

Essence  of  lemons,  of  cedrat,  of  balm- 
mint,  of  lavender,  each  1  ounce  4 
drachms  ;  neroli  and  essence  of  the  seed 
of  anthos,  each  4  drachni3  ;  essence  of 
jasmin,  1  ounce ;  of  bergamot,  12  ounces. 
Filter  and  preserve  for  use. 


Cadet  de  Gassincourt  has  proposed  to 
prepare  eau  de  Cologne  by  the  following 
recipe  ;  Take  alcohol  at  32°  B.,  2  quarts  ; 
neroli,  essence  of  cedrat,  of  orange,  of 
lemon,  of  bergamot,  of  rosemary,  each  24 
drops  ;  add  2  drachms  of  the  seeds  of 
lesser  cardamoms,  distil  by  the  heat  of  a 
water  bath ,  a  pint  and  a  half.  "When  pre- 
pared as  thus  by  simple  mixture  of  essen- 
ces without  distillation,  it  is  never  so 
good. 

EAU  DE  LUCE  is  a  compound  formed 
of  the  distilled  oil  of  amber  and  water  of 
ammonia. 

EAU  DE  JAVELLE.  Solution  of  hy- 
pochlorite of  soda. 

EBULLITION.  When  the  bottom  of 
an  open  vessel  containing  water  is  ex- 
posed to  heat,  the  lowest  stratum  of  fluid 
immediately  expands,  becorm  s  therefore 
specifically  lighter,  and  is  forced  upwards 
by  the  superior  gravity  of  the  superin- 
cumbent colder  and  heavier  particles. 
The  heat  is  in  this  way  diffused  through 
the  whole  liquid  mass,  not  by  simple  com- 
munication of  that  power  from  particle  to 
particle  as  in  solids,  called  the  conduction 
of  caloric,  but  by  a  translation  of  the 
several  particles  from  the  bottom  to  the 
top,  and  the  top  to  the  bottom,  in  alter- 
nate succession.  This  is  denominated 
the  carrying  power  of  fluids,  being  com- 
mon to  both  liquid  and  gaseous  bodies. 
These  internal  movements  maybe  render- 
ed very  conspicuous  and  instructive,  by 
mingling  a  little  powdered  amber  with 
water,  contained  in  a  tall  glass  cylinder, 
standing  upon  a  sand-bath.  A  column  of 
the  heated  and  lighter  particles  will  be 
seen  ascending  near  the  axis  of  the  cylin- 
der, surrounded  by  a  hollow  column  of 
the  cooler  ones  descending  near  the  sides. 
That  this  molecular  translation  or  loco- 
motion is  almost  the  sole  mode  in  which 
fluids  get  heated,  may  be  demonstrated 
by  placing  the  middle  of  a  pretty  long 
glass  tube,  nearly  filled  with  water,  ob- 
liquely over  an  argand  flame.  The  upper 
half  of  the  liquid  will  soon  boil,  but  the 
portion  under  the  middle  will  continue 
cool,  so  that  a  lump  of  ice  may  remain  for 
a  considerable  time  at  the  bottom.  WThen 
the  heat  is  rapidly  applied  the  liquid  is 
thrown  into  agitation,  in  consequence  of 
elastic  vapor  being  suddenly  generated 
at  the  bottom  of  the  vessel,  and  being  as 
suddenly  condensed  at  a  little  distance 
above  it  by  the  surrounding  cold  columns. 
These  alternate  expansions  and  contrac- 
tions of  volume  become  more  manifest  as 
the  liquid  becomes  hotter,  and  constitute 
the  simmering  vibratory  sound  which  is 


egg] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


143 


the  prelude  of  ebullition.  The  whole 
mass  being  now  heated  to  a  pitch  com- 
patible with  its  permanent  elasticity,  be- 
comes turbulent  and  explosive  under  the 
continued  influence  of  tire,  and  emitting 
more  or  less  copious  volumes  of  vapor,  is 
said  to  boil.  The  further  elevation  of 
temperature  by  the  influence  of  caloric, 
becomes  impossible  in  these  circumstan- 
ces with  almost  all  liquids,  because  the 
vapor  carries  off  from  them  as  much  heat 
in  a  latent  state  as  they  are  capable  of  re- 
ceiving from  the  fire. 

Thetemperature  at  which  liquids  boil 
in  the  open  air  varies  with  the  degree  of 
atmospheric  pressure,  being  higher  as 
that  is  increased,  and  lower  as  it  is  di- 
minished. Hence  boiling  water  is  colder 
by  some  degrees  in  bad  weather,  or  in  an 
elevated  situation,  with  a  depressed  bar- 
ometer, than  in  fine  weather,  or  at  the 
bottom  of  a  coal-pit,  when  the  barometer 
is  elevated.  A  high  column  of  liquid, 
also,  by  resisting  the  discharge  of  steam, 
raises  the  boiling  point.  In  vacuo,  all  li- 
quids boil  at  a  temperature  about  124°  F. 
lower  than  under  the  average  atmospheric 
pressure. 

The  following  is  a  table  of  the  boiling 
points  of  a  few  substances,  on  Fahren- 
heit's scale : 

Ether,  100°    Alcohol,  173° 

Nitric  Acid,  210°    Water,  212° 

Solution  of  Salt,     224°    Chloride  of  Calci- 
Muriatic  Acid,         222°  um,  285° 

Oil  of  Turpentine,  815°  Sulphuric  Acid,  600° 
Phosphorus,  554°    Sulphur,  570° 

Linseed  Oil,  640°    Mercury,  662° 

M.  Marcet  has  shown,  that  whatever 
the  nature  of  the  boiler,  the  temperature 
of  the  steam  is  invariably  lower  than  that 
of  the  water  from  which  the  steam  is 
generated.  In  glass  vessels,  this  differ- 
ence amounts,  on  an  average,  to  1,908  de- 
grees,— in  metal  vessels,  only  to  between 
0.27  and  0.36  of  a  degree.  There  is  but 
one  exception  to  this  rule,  viz:  where  the 
inside  of  the  boiler  is  coated  with  a  thin 
layer  of  sulphur,  gum  lac,  or  any  other 
matter  possessing  "an  adhesion  for  water. 
In  that  case  the  boiling  water  and  the 
steam  have  the  same  temperature.  Thus, 
contrary  to  the  generally  received  notion, 
it  is  not  in  metal  vessels  that  the  boiling 
point  is  lower  under  a  stronger  pressure, 
but  in  glass  vessels;  if  the  latter  are 
coated  with  sulphur,  gum  lac,  &c. 

EDULCOEATION.  A  chemical  term 
applied  to  the  cleansing  of  substances, 
especially  pulverulent  precipitates,  by  the 
repeated  affusion  of  water,  so  as  to  re- 
move all  soluble  matters,  and  render  them 
free  from  taste  and  smell. 


EFFEEVESCENCE.  The  escape  of 
gaseous  matter  from  liquids,  as  in  the 
act  of  fermentation.  All  liquids  from 
which  bubbles  of  gas  rapidly  escape,  so 
as  to  resemble  boiling,  are  said  to  effer- 

EFFLOKESCENCE.  Is  the  spontane- 
ous conversion  of  a  solid,  usually  crystal- 
line, into  a  powder,  in  consequence  either 
of  the  abstraction  of  the  combined  water 
by  the  air,  as  happens  to  the  crystals 
of  sulphaoe  and  carbonate  of  soda ;  or  by 
the  absorption  of  oxygen  and  the  forma- 
tion of  a  saline  compound,  as  in  the  case 
of  alum  schist,  and  iron  pyrites.  Salt- 
petre appears  as  an  efflorescence  upon 
the  ground  and  walls  in  many  situa- 
tions.' 

EDGE-TOOLS.  (See  Cutlery  and 
Steel.) 

EGG.  The  ovum  of  birds  and  other 
oviparous  animals.  The  changes  which 
the  hen's  egg  undergoes  during  incubation 
have  been  described  by  Sir  E.  Home  in 
the  Philosophical  Transactions  for  the 
year  1822,  page  339,  and  illustrated  by  a 
beautiful  scries  of  plates  after  Bauer's 
drawings  ;  the  same  volume  also  contains 
a  vamable  paper  by  Dr.  Prout  on  the 
same  subject,  but  chiefly  in  reference  to 
the  chemical  changes  of  the  egg  during 
that  process.  The  specific  gravity  of 
new-laid  eggs  at  first  rather  exceeds  that 
of  water,  varying  from  1080  to  1090 ;  h\\t 
they  soon  become  lighter,  and  swim  on 
water,  in  consequence  of  evaporation 
through  the  pores  of  the  shell.  When 
an  egg  is  boiled  in  water  and  suffered  to 
cool  in  the  air,  it  looses  about  32  hund- 
redths of  a  grain  of  saline  matter,  to- 
gether with  a  trace  of  animal  matter  and 
free  alkali.  The  mean  weight  of  a  hen's 
egg  is  about  875  grains,  of  which  the  shell 
and  its  inner  membrane,  weigh  93-7 
grains,  the  albumen,  or  white,  529*8  grs., 
and  the  yolk  251*8  grs.  The  shell  con- 
tains about  2  per  cent,  of  animal  matter 
and  1  per  cent,  of  the  phosphates  of  lime 
and  magnesia,  the  remainder  being  carbo- 
nate of  lime,  with  a  trace  of  carbonate 
of  magnesia.  When  the  yolk  of  a  haid- 
boiled  egg  is  digested  in  repeated  por- 
tions of  strong  alcohol,  there  remains  a 
white  residue  haviug  the  leading  charac- 
ters of  albumen,  but  containing  phospho- 
rus in  some  peculiar  state  of  combina- 
tion ;  the  alcoholic  solution  ib  yellow, 
and  deposits  a  crystalline  fatty  matter, 
and  when  distilled  leaves  a  yellow  oil 
The  albumen  of  the  egg  contains  sulphur 
The  use  of  the  phosphorus  is  to  yield 
phosphoric  acid  to  form  the  bones  of  the 


144 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ela 


chick ;  but  the  source  of  the  lime  with 
which  it  is  combined  is  not  apparent,  for 
it  has  not  been  detected  in  the  soft  parts 
of  the  egg,  and  hitherto  no  vascular  com- 
munication has  been  discovered  between 
the  chick  and  the  shell. 

EGGS,  HATCHING.  (See  Incubation, 

EIDER-DOWN  is  a  kind  of  precious 
down,  so  called  because  it  is  obtained 
from  the  Eider-duck.  These  birds  build 
their  nests  among  precipitous  rocks,  and 
the  female  lines  them  with  fine  feathers 
plucked  from  her  breast,  among  which 
she  lays  her  five  eggs.  The  natives  of 
the  districts  frequented  by  the  eider- 
ducks  let  themselves  down  bv  cords 
among  the  dangerous  cliffs,  to  collect  the 
down  from  the  nests.  It  is  used  to  fill 
coverlets,  pillows,  cushions,  &c. 

ELAINE  is  the  name  given  by  Chev- 
reul  to  the  thin  oil  which  may  be  expel- 
led from  tallow,  and  other  fats,  solid  or 
fluid,  by  pressure  either  in  their  natural 
state,  or  after  being  saponified,  so  as  to 
harden  the  stearine.  It  may  be  extracted 
also  by  digesting  the  fat  in  7  or  8  times 
its  weight  of  boiling  alcohol,  spec.  grav. 
0-798,  till  it  dissolves  the  whole.  Upon 
cooling  the  solution,  the  stearine  falls  to 
the  bottom,  while  the  elaine  collects  in  a 
layer  like  olive  oil,  upon  the  surface  of 
the  supernatant  solution,  reduced  by 
evaporation  to  one-eighth  of  its  bulk.  If 
this  elaine  be  now  exposed  to  a  cold  tem- 
perature, it  will  deposit  its  remaining 
stearine  and  become  pure.  See  Fat,  Oils, 
and  Stearine. 

ELASTICITY.  In  Physics,  that  prop- 
erty which  certain  bodies  possess  of  re- 
covering their  primitive  form  and  dimen- 
sions after  the  external  force  by  which 
they  have  been  dilated  or  compressed  or 
bent  is  withdrawn. 

The  theory  of  elasticity  must  be  deduct- 
ed from  some  hypothesis  respecting  the 
constitution  of  matter.  The  simplest  and 
most  general  view  which  can  be  taken  of 
the  subject  is?  that  all  matter  is  compo- 
sed of  indefinitely  small  parts  or  molecules 
acted  upon  by  attractive  and  repulsive 
forces.  The  attractive  forces  result  from 
the  action  of  the  molecules  on  each  other  ; 
the  repulsive  forces  from  the  caloric  with 
which  the  molecules  are  combined. 
From  the  combined  action  of  these  two 
forces,  the  attraction  of  matter  and  the 
repulsion  of  caloric,  the  different  forms 
of  matter  and  its  varied  physical  proper- 
ties may  be  explained. 

This  view  of  the  constitution  of  bodies 
supposes  that  the  molecules  are  not  in 


contact,  but  at  a  certain  distance  from 
each  other,  which,  though  it  is  to  be  re- 
garded as  indefinitely  small  in  compari- 
son of  any  distance  appreciable  by  our 
senses,  admits  nevertheless  of  increase 
and  diminution.  When  a  body  is  in  a 
state  of  rest,  the  opposite  forces  which 
any  two  of  its  contiguous  molecules  exer- 
cise on  each  other  are  in  equilibrium. 
The  energy  of  the  forces  also  depends  on 
the  distance  between  the  two  molecules, 
or,  in  mathematical  language,  is  a  func- 
tion of  that  distance.  If  the  distance  be 
increased  within  the  limits  of  the  action 
of  the  forces,  both  forces  are  diminished ; 
and  if  the  distance  is  diminished,  both 
are  increased,  but  not  in  the  same  pro- 
portion. If  the  interval  at  which  the  two 
forces  balance  each  other  be  diminished, 
the  repulsive  force  becomes  stronger  than 
the  attractive  force,  and  the  two  mole- 
cules are  repelled  from  each  other;  on  the 
contrary,  if  the  distance  be  increased,  the 
attractive  force  acquires  the  superiority, 
and  the  molecules  are  drawn  towards 
each  other. 

Elasticity  is  perfect  when  the  body  ex- 
actly recovers  its  primitive  form,  after  the 
force  by  which  it  is  bent  or  compressed 
or  dilated  has  been  removed,  in  the  same 
time  as  was  required  for  the  force  to  pro- 
duce the  alteration.  This  perfect  elasti- 
city is,  however,  not  found  in  any  of  the 
boclies  of  nature  ;  the  aeriform  fluids  or 
gases  are  those  whose  elasticity  approach- 
es the  nearest  to  it.  Hard  bodies,  even 
tempered  steel  and  ivory,  possess  it  in  a 
less  degree ;  in  fluid  substances  the  elas- 
tic force  is  greatly  diminished;  and  in 
soft  bodies,  as  butter,  moist  clay,  it  en- 
tirely disappears.  In  solid  bodies  the 
elastic  force  is,  in  general  diminished  by 
use,  or  by  a  long  continued  application  of 
a  straining  force.  A  bow  which  has  been 
long  bent,  or  a  spring  which  has  been 
long  compressed,  will  not  entirely  recover 
its  original  form.  In  many  cases  the 
elasticity  of  a  body  can  "be  augmented  by 
producing  a  closer  aggregation  of  the 
molecules.  The  metals,  for  example,  are 
rendered  more  elastic  by  hammering  them 
cold,  or  by  alloys.  Iron  and  steel  acquire 
a  greater  elasticity  by  ternfering  ;  that  is, 
by  producing  a  sudden  contraction  of 
their  volumes  when  they  have  been  ex- 
panded by  heat. 

The  principal  phenomena  of  elastic 
bodies  are  the  following  :—-l,  That  an 
elastic  body  (the  elasticity  being  sup- 
posed perfect)  exerts  the  same  force  in 
endeavoring  to  restore  itself,  as  that  with 
which  it  was  compressed  or  bent.    2,  The 


ele] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


145 


force  of  elastic  bodies  is  exerted  equally 
in  all  directions,  but  the  effect  chiefly 
takes  place  on  the  side  on  which  the  re- 
sistance is  the  least.  3,  When  an  elastic 
solid  body  is  made  to  vibrate  by  a  sudden 
stroke,  tlie  vibrations  are  performed  in 
equal  times,  to  whatever  part  of  the  body 
the  stroke  may  be  communicated.  Thus, 
sonorous  bodies  always  emit  sounds  of 
the  same  pitch ;  and  the  difference  of  the 
pitch  depends  on  the  greater  or  less  fre- 
quency of  the  vibrations  of  the  sonorous 
body.  4,  A  body  perfectly  incompressi- 
ble cannot  be  elastic,  therefore  bodies 
perfectly  solid  can  have  no  elasticity ;  and 
hence,  also,  the  small  degree  of  elasticity 
belonging  to  the  liquids  which  are  emi- 
nently incompressible. 

ELASTIC  BANDS.  The  manufacture 
of  braces  and  garters,  with  threads  of 
caoutchouc,  either  naked  or  covered, 
sterns  to  have  originated,  some  time  ago, 
in  Vienna,  whence  it  was  a  few  years 
since  imported  into  Paris,  and  thence 
into  this  country.  At  first  the  pear- 
shaped  bottle  of  Indian  rubber  was  cut 
into  long,  narrow  strips  by  the  scissors  ; 
a  single  operative  turning  off  only  about 
100  yards  in  a  day,  by  cutting  the  pear 
in  a  spiral  direction.  He  succeeded  next 
in  separating  with  a  pair  of  pincers  the 
several  layers  of  which  the  bottle  was 
composed.  Another  mode  of  obtaining 
fine  threads  was  to  cut  them  out  of  a 
bottle  which  had  been  rendered  thin  by 
inflation  with  a  forcing  pump.  All  these 
operations  are  facilitated  by  previously 
steeping  the  caoutchouc  in  boiling  water, 
in  its  moderately  inflated  state.  More 
recently,  machines  have  been  success- 
fully employed  for  cutting  out  these  fila- 
ments ;  but  for  this  purpose  the  bottle  of 
caoutchouc  is  transformed  into  a  disc  of 
equal  thickness  in  all  its  parts,  and  per- 
fectly circular.  This  preliminary  opera- 
tion is  executed  as  follows  :  1st,  the  bot- 
tle, softened  in  hot  water,  is  squeezed 
between  the  two  plates  of  a  press,  the 
neck  having  been  removed  beforehand, 
as  useless  in  this  point  of  view ;  2d,  the 
bottle  is  then  cut  into  two  equal  parts, 
and  is  allowed  to  consolidate  by  cooling 
before  subjecting  it  to  the  cutting  instru- 
ment. When  the  bottle  is  strong  enough, 
and  of  variable  thickness  in  its  different 
points,  each  half  is  submitted  to  power- 
ful pressure  in  a  very  strong  cylindrical 
mould  of  metal,  into  which  a  metallic 
plunger  descends,  which  forces  the  caout- 
chouc to  take  the  form  of  a  flat  cylinder 
with  a  circular  base.  This  mould  is 
plunged  into  hot  water  during  the  com- 


pression. A  stem  or  rod  of  iron,  which 
goes  across  the  hollow  mould  and  piston, 
retains  the  latter  in  its  place,  notwith- 
standing the  resilience  of  the  caoutchouc, 
when  the  mould  is  taken  from  the  press. 
The  mould  being  then  cooled  in  water, 
the  caoutchouc  is  withdrawn. 

The  transformation  of  the  disc  of 
caoutchouc  into  fine  threads  is  perform- 
ed by  two  machines  ;  the  first  of  which 
cuts  it  into  a  riband  of  equal  thickness 
in  its  whole  extent,  running  in  a  spiral 
direction  from  the  circumference  to  the 
centre ;  the  second  subdivides  this  riband 
lengthwise  into  several  parallel  filaments 
much  narrower,  but  equally  thick. 

The  threads,  when  brought  to  this 
state  of  slenderness,  are  put  success  ively 
into  tubs  filled  with  cold  water ;  they  are 
next  softened  in  hot  water,  and  elongated 
as  much  as  possible  in  the  following  man- 
ner : — They  are  wound  upon  a  reel  turn- 
ed quickly,  while  the  operative  stretches 
the  caoutchouc  thread  with  his  hand. 
In  this  way  it  is  rendered  8  or  10  times 
longer.  The  reels  when  thus  filled  are 
placed  during  some  days  in  a  cold  apart- 
ment, where  the  threads  become  firm, 
and  seem  to  change  their  nature. 

This  state  of  stiffness  is  essential  for 
the  success  of  the  subsequent  operations. 
The  threads  are  commonly  covered  with 
a  sheath  of  silk,  cotton,  or  linen,  by  a 
braiding  machine,  and  are  then  placed  as 
warp  in  a  loom,  in  order  to  form  a  nar- 
row web  for  braces,  garters,  &c.  If  the 
gum  were  to  exercise  its  elasticity  during 
this  operation,  the  different  threads 
would  be  lengthened  and  shortened  in 
an  irregular  manner,  so  as  to  form  a 
puckered  tissue.  It  is  requisite  there- 
fore to  weave  the  threads  in  their  rigid 
and  inextensible,  or  at  least  incontractile 
condition,  and  after  the  fabric  is  woven 
to  restore  to  the  threads  of  caoutchouc 
their  appropriate  elasticity.  This  re- 
storation is  easily  effected  by  passing  a 
hot  smoothing  iron  over  the  tissue  laid 
smoothly  upon  a  table  covered  with 
blanket  stuff. 

ELECTIVE  AFFINITY,  denotes  the 
order  of  preference,  so  to  speak,  in  which 
the  several  chemical  substances  choose  to 
combine ;  or  really,  the  gradation  of  at- 
tractive force  infused  by  Almighty  Wis- 
dom among  the  different  objects* of  na- 
ture, which  determines  perfect  uniformity 
and  identity  in  their  compounds  amidst 
indefinite  variety  of  combination.  The 
discussion  of  this  interesting  subject  be- 
longs to  pure  chemistry. 

ELECTRICAL  WAVES,  Velocity  of. 


146 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[• 


Some  ingenious  experiments  have  been 
performed  at  the  Cincinnati  Observatory, 
in  connection  with  the  magnetic  tele- 

fraph,  to  ascertain  if  there  be  any  sensi- 
le  time  occupied  in  the  transmission  of 
the  wave  or  current  of  electricity  between 
the  two  points  where  relative  longitudes 
are  required.  If  there  be  a  sensible  velo- 
city, it  must  involve  a  correction  for  the 
difference  of  longitude  as  determined  by 
star  signals  passed  along  the  waves  or 
through  the  ground  by  electrical  cur- 
rents "between  the  two  observatories. 
Thus  far,  Professor  Mitchell  says,  all  re- 
sults tend  to  the  conclusion  that  there  is 
no  sensible  wave  time.  Other  methods 
may  lead  to  a  different  conclusion.  Ex- 
periments performed  some  months  since, 
by  Mr.  Walker,  lead  that  gentleman  to 
believe  he  had  detected  and  measured  a 
wave  time.  The  subject  is  interesting, 
and  now  becomes  important  as  an  ele- 
ment in  the  determination  of  longitudes 
by  the  magnetic  telegraph. 

ELECTRIC  CLOCK.  The  first  public 
clock  of  this  kind  in  the  United  States 
was  placed  above  the  chief  entry  of  the 
Bank  of  Louisiana,  New  Orleans.  It  is 
a  beautiful  object  to  look  at  from  the 
street,  but  there  is  something  still  more 
interesting  connected  with  it.  This  con- 
sists of  the  method  employed  for  setting 
the  hands  in  motion,  which  is  by  elec- 
tricity. 

At  the  Bank  of  Louisiana  there  is  no- 
thing but  the  dial  and  the  hour  and  mi- 
nute hands ;  the  clock  is  in  Mr.  Foster's 
bfcore,  where  also  is  the  galvanic  pile  from 
which  the  conducting  wire  leads  to  the 
Bank,  past  the  adjoining  houses,  and 
along  which  the  electric  current  travels 
that  moves  the  hands.  A  person  stand- 
ing in  the  street  can  see  both  by  day  and 
by  night  the  progress  of  the  minute 
hf<nd,  which  moves  every  half  minute. 
(See  Chronograph.) 

ELECTRO-MAGNETISM.  When  a 
current  of  electricity  is  traversing  any 
substance,  or  when  electricity  is  in  motion 
magnetism  is  at  the  same  time  developed. 
This  fact  was  first  observed  by  Professor 
Oersted,  of  Copenhagen,  and  has  be- 
come the  source  of  an  important  series 
of  discoveries  included  under  the  above 
term.  The  excitation  of  magnetism  de- 
pends upon  quantity  of  electricity,  and  is 
best  observed  in  the  wire  which  closes 
the  voltaic  circle,  especially  of  one  or 
more  pairs  of  large  plates.  If  a  magnetic 
noedle  be  brought  near  a  wire  through 
which  an  electric  current  is  passing,  it 
will  immediately  deviate  from  its  usual 


position,  and  assume  a  new  one,  depen- 
dent upon  the  relative  position  of  the 
needle  and  the  wire.  On  placing  the 
electric  wire  above  and  parallel  to  the 
magnet,  the  pole  next  the  negative  end 
of  the  battery  always  moves  to  the  west; 
and  when  the  wire  is  placed  under  the 
needle,  the  same  pole  turns  to  the  east. 
When  the  electric  wire  is  on  the  same 
horizontal  plane  with  the  needle,  no  de- 
clination takes  place;  but  the  magnet 
shows  a  disposition  to  move  in  a  vertical 
direction,  the  pole  next  the  negative  side 
of  the  battery  Deing  depressed  when  the 
wire  is  to  the  west  ot  it,  and  elevated 
when  it  is  to  the  east. 

The  magnetic  phenomena  of  a  wire 
transmitting  electricity  are  such  as  ap- 
pear to  depend  upon  the  circulation  of 
magnetism  at  right  angles  to  the  electric 
current,  so  that  if 
N  P  represent  the  * 

wire  transmitting     »i^—         j  ^-]g 

a  current  of  clec-  s 

tricity  in  the  di- 
rection of  the  horizontal  darts,  a  current 
of  magnetism  will  be  established  in  the 
direction  of  the  vertical  dart,  appearing 
to  move  round  the  axis  of  the  electric 
current ;  hence  the  term  vertiginous  or 
rotary  magnetism,  applied  to  these  phe- 
nomena; and  hence  the  motion  of  the 
pole  Of  the  magnet  round  the  electric 
wire,  or  of  the  electric  wire  round  the 
pole  of  the  magnet,  when  they  respec- 
tively are  so  arranged  as  to  be  able  to 
move  freely  in  any  direction.  If  a  steel 
needle  be  placed  in  contact  with  the 
electric  wire,  and  parallel  to  it,  it  acquires 
opposite  magnetisms  upon  its  two  sides ; 
but  if  it  be  placed  at  right  angles  to  the 
connecting  wire,  it 
becomes  polar,  and 
permaner  " 
netic. 
trie  wire 
ed    into    a    spiral, 

and  the  steel  needle  placed  within  it  (as 
in  the  cut),  it  is  retained  there,  and  be- 
comes a  more  powerful  magnet  in  conse- 
quence of  the  repetitions  and  direction 
of  the  electric  and  magnetic  currents,  as 
will  be  evident  from  the  annexed  figure, 
where  a  represents  a  glass  tube  with  the 
wire  T  conveying  the  electric  current 
twisted  round  it ;  the  darts  at  the  ends 
of  which  show  the  ingress  and  egress  of 
the  electricity,  and  the  transverse  darts 
the  direction  of  the  magnetic  current. 
If  the  cylinder  round  which  the  wire 
conveying  the  electric  current  is  twisted 
be  of  steel,  it  becomes  a  permanent  mag- 


ues  polar,  and  ^-.-^..^ tl  i 

anently  mag-  pJ^^^&^t^>T\ 

Iftheelec-  ^KpSfcb 

fire  be  twist-  "' 


•] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


147 


net;  if  of  pure  soft  iron,  it  becomes  a 
temporary  magnet,  so  long  as  the  electric 
current  is  in  motion,  and  s 
and  n  are  powerfully  opposed 
poles.  If  the  bar  be  bent,  as 
m  the  annexed  cut,  a  power- 
ful horse-shoe  magnet  is  ob- 
tained when  the  ends  t  n  of 
the  copper  wire  twisted  round 
U  are  connected  with  the  vol- 
taic circle ;  and  a  single  pair  of  plates  is 
sufficient  for  the  purpose. 

ELECTRO-MAGNETIC  ORE  SEPA- 
RATOR. Mr.  Ransom  Cook  has  pa- 
tented a  machine  for  separating  the  mag- 
netic iron  from  the  rock  with  which  lit 
is  associated.  He  employs  a  revolving 
cylinder  or  drum  with  electro-magnetic 
poles  on  its  circumference.  When  the 
crushed  ore  passes  underneath  the  re- 
volving cylinder,  the  oxide  of  iron  is  at- 
tracted^ to  the  cylinder,  leaving  the  im- 
purities behind  :  when  the  drum  is 
charged  with  ore,  the  cylinder  is  freed 
from  connection  with  the  battery,  and 
the  ore  then  losing  its  attractive  force, 
drops  off  into  the  receiving-box. 

ELECTRO-MAGNETISM.  (Motive 
Powek  of.)  Numerous  attempts  have 
been  made  to  apply  electro-magnetism  as 
a  power  for  moving  machines,  and  parti- 
cularly by  the  apparatus  employed  by 
Jacobi,  I3al  Negro,  M'Gauley,  Wheat- 
stone,  and  the  machines  recently  con- 
structed by  Mr.  Hjorth.  However,  not- 
withstanding the  talent  which  has  been 
devoted  to  this  interesting  subject,  and 
the  large  amount  of  money  which  has 
been  spent  in  the  construction  of  ma- 
chines, the  public  are  not  yet  in  posses- 
sion of  any  electro-magnetic  machine 
which  is  capable  of  exerting  power  eco- 
nomically. 

The  most  remarkable  experiments  are 
those  of  Professor  Jacobi,  who,  in  1838 
and  '39,  succeeded  in  propelling  a  boat 
upon  the  Neva  at  the  rate  of  four  miles 
an  hour. 

Mr.  Hjorth's  engine  embraces  many 
new  features  that  promise  to  render  the 
power  more  effective  than  hitherto.  One 
of  the  electro-magnets  made  for  the  large 
engine,  in  a  recenl  trial,  supported  near- 
ly 5000  lbs.,  and  its  attractive  force  at  \ 
of  an  inch  was  equal  to  nearly  1500  lbs. 
As  this  force  can  be  multiplied  without 
limits,  it  is  reduced  to  a  question  of  econ- 
omy and  convenience. 

The  power  of  electro-magnets  can  be 
increased  without  limitation.  A  voltaic 
current  produced  by  the  chemical  distur- 
bance ot  the  elements  of  any  battery  no 


matter  what  its  form  may  be,  is  capable 
of  producing  by  induction  a  magnetic 
force,  this  magnetic  force  being  always  in 
an  exact  ratio  to  the  amount  of  matter 
(zinc,  iron,  or  otherwise)  consumed  in 
the  battery. 

The  greatest  amount  of  magnetic  force 
is  produced  when  the  chemical  action 
is  most  rapid. 

Hence,  in  all  machines,  it  is  more 
economical  to  employ  a  battery  of  intense 
action,  than  one  in  which  the  chemical 
action  is  slow.  It  has  been  proved  by 
Mr.  Joule,  and  most  satisfactorily  con- 
firmed by  Mr.  R.  Hunt,  that  one-horse 
power  is  obtainable  in  an  electro-magnetic 
engine,  the  most  favorably  constructed 
to  prevent  loss  of  power,  at  the  cost  of 
45  lbs.  of  zinc,  in  a  Grove's  battery,  in 
24  hours,  while  15  lbs.  are  consumed  in 
the  same  time  to  produce  the  same  power 
in  a  battery  of  l)aniell's  construction. 
The  intensity  of  Darnell's  battery  being 
|  that  of  Grove's.  The  cause  of  this  was 
referred  to  the  necessity  of  producing 
a  high  degree  of  excitement,  to  overcome 
the  resistance  which  the  molecular  forces 
offer  to  the  electrical  perturbations,  on 
which  the  magnetic  force  depends. 

What  amount  of  magnetic  power  can 
be  obtained  from  an  equivalent  of  any 
material  consumed  ?  Tne  following,  re- 
garded as  the  most  satisfactory  results 
yet  obtained : — 1.  The  force  of  voltaic 
current  being  equal  to  673,  the  number 
of  grains  of  zinc  destroved  per  hour  was 
151,  which  raised  9000  lbs.  one  foot  high 
in  that  time.  2.  The  force  of  current 
being,  relatively,  1300,  the  zinc  destroyed 
in  an  hour  was  291  grains,  which  raised 
10,030  lbs.  through  the  space  of  one  foot. 
3.  The  force  being  1000,  the  zinc  con- 
sumed was  223  grains  ;  the  weight  lifting 
one  foot  12,672  lbs.  The  estimations 
made  by  Messrs.  Scoresby  and  Joule, 
and  the  results  obtained  by  Oersted,  and 
more  recently  by  Mr.  Hunt,  very  nearly 
agree ;  and  it  was  stated  that  one  grain 
of  coal  consumed  in  the  furnace  of  a  Cor- 
nish engine  lifted  143  lbs.  one  foot  high, 
whereas  one  grain  of  zinc  consumed"  in 
the  battery  lifted  only  80  lbs.  The  cost 
of  1  cwt.  of  coal  is  under  9d. ;  the  cost 
of  1  cwt.  of  zinc  is  above  216d.  There- 
fore, under  the  most  perfect  conditions, 
magnetic  power  must  be  nearly  25  times 
more  expensive  than  steam  power.  But 
the  author  proceeded  to  show  that  it  was 
almost  proved  to  be  an  impossibility  ever 
to  reach  this,  owing,  in  the  first  place,  to 
the  rate  with  which  the  force  diminishes 
through  space.    As  the  mean  of  a  great 


148 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ele 


many  experiments  on  a  large  variety  of 
magnets,  of  different  forms  and  modes  of 
construction,  the  following  result  was 
given : 

Magnet  and  armature  in  contact,  lbs. 

lifting  force      -  -       220 

"  distant  1-250  of  an  inch    90  6 

"      1-125        "  50  7 

"  "      1-63  "  50  1 

"      1-50  "  40  5 

Thus  at  one-fiftieth  of  an  inch  distance 

four-fifths  of  the  power  is  lost.      This 

great  reduction  of  power  takes  place  when 

the   magnets    are    stationary.      Mr.    E. 

Hunt  has  also  shown  that  the  moment 

they  were  set  in  motion  a  great  reduction 

of  the  original  power  immediately  took 

Slace  :  that,  indeed,  any  disturbance  pro- 
ucecl  near  the  poles  of  a  magnet  dimin- 
ished, during  the  continuance  of  the  mo- 
tion, its  attractive  force.  The  attractive 
force  of  a  magnet  being  150  lbs.  when 
free  of  disturbance,  fell  to  one-half,  by 
occasioning  an  armature  to  revolve  near 
its  poles.  -  Therefore,  when  a  system  of 
magnets  which  had  been  constructed  to 
produce  a  given  power  is  set  in  revolu- 
tion, every  magnet  at  once  suffers  an  im- 
mense loss  of  power,  and  consequently 
their  combined  action  falls  in  practice 
very  far  short  of  their  estimated  power. 
This  fact  has  not  been  before  distinctly 
stated,  although  it  is  well  known  that 
Jacobi  observed  it.  And  not  merely 
does  each  magnet  thus  sustain  an  actual 
loss  of  power,  but  the  power  thus  lost 
is  converted  into  a  new  form  of  force,  or 
or  rather  becomes  a  current  of  electri- 
city, acting  in  opposition  to  the  primary 
current  by  which  the  magnetism  is  in- 
duced. Erom  an  examination  of  all  these 
results,  Mr.  Hunt  is  disposed  to  regard 
electro-magnetic  power  as  impracticable, 
on  account  of  its  cost,  which  must  neces- 
sarily be,  he  conceives,  under  the  best 
conditions,  fifty  times  more  expensive 
than  steam  power,  and  i3  at  present  at 
least  150  times  as  expensive. 

On  the  other  hand,  in  opposition  to 
the  foregoing  conclusions,  Protessor  Page, 
of  Washington,  has  constructed  a  ma- 
chine either  for  locomotion  or  station- 
ary work.  He  has  exhibited  it  in  the 
Smithsonian  Institute,  and  a  Washington 
paper  thus  describes  the  circumstance  : 

"  He  then  exhibited  his  engine,  of  be- 
tween four  and  five  horse  power,  operat- 
ed by  a  battery  within  the  space  of  three 
cubic  feet.  It  looked  very  unlike  a  mag- 
netic machine.  It  was  a  reciprocating 
engine  of  two  feet  stroke,  and  the  whole 
battery  and  engine  weighed  about  one 


ton.  When  the  power  was  thrown  on 
by  the  motion  of  a  lever,  the  engine 
started  off  magnificently,  making  one 
hundred  and  fourteen  strokes  per  min- 
ute ;  though  when  it  drove  a  circular  saw 
ten  inches  in  diameter,  sawing  up  boards 
an  inch  and  a  quarter  thick  into  laths, 
the  engine  made  but  about  eighty  strokes 
per  minute.  There  was  great  anxiety  on 
the  part  of  the  spectators  to  obtain  speci- 
mens of  these  laths,  to  preserve  as  tro- 
phies of  this  great  mechanical  triumph. 
The  force  operating  upon  his  magnetic 
cylinder  throughout  the  whole  motion  of 
two  feet,  was  stated  to  be  six  hundred 
pounds  when  the  engine  was  moving 
very  slowly,  but  he  had  not  been  able  to 
ascertain  what  the  force  was  when  the 
engine  was  running  at  a  working  speed, 
though  it  was  considerably  less.  The 
most  important  and  interesting  point, 
however,  is  the  expense  of  the  power. 
Professor  Page  stated  that  he  had  reduced 
the  cost  so  far,  that  it  was  less  than  steam 
under  many  and  most  conditions,  though 
not  so  low  as  the  cheapest  steam  engines. 
With  all  the  imperfections  of  the  engine, 
the  consumption  of  three  pounds  of  zinc 
per  day  would  produce  one  horse  power. 
The  larger  his  engines  (contrary  to  what 
has  been  known  before),  the  greater  the 
economy.  Professor  Page  was  himself 
surprised  at  the  result.  There  were  yet 
practical  difficulties  to  be  overcome ;  the 
battery  had  yet  to  be  improved :  and  it 
remained    to   try  the  experiment  on  a 

frander  scale,  to  make  a  power  of  one 
undred  horse,  or  more.  (^Locomotive.) 

ELECTRO  METALLURGY.  By  this 
elegant  art  the  most  exact  copies  of  any 
natural  or  artificial  object  can  be  obtained, 
or  the  surface  of  any  body  non-metallic 
or  metal  may  become  coated  with  a  thin 
layer  or  film  of  copper,  gold,  and  silver, 
or  a  few  other  metals.  The  practical  de- 
tails of  the  arrangement  is  all  that  can 
find  a  space  in  these  pages. 

On  the  Forms  and  Arrangement  of  Ap- 
paratus.— In  the  deposition  of  metals 
where  voltaic  electricity  is  the  power  em- 
ployed, there  are  two  descriptions  of  ar- 
rangement :  the  first  where  the  surface 
on  which  the  deposit  is  formed  is  itself  a 
part  of  the  apparatus  whence  the  power 
is  generated  ;  the  other  in  which  the  ob- 
ject receiving  the  deposit  forms  no  part 
of  the  apparatus,  but  where  the  power  is 
procured  from  a  battery ;  the  former  is 
termed  the  single  cell,  the  latter  the  bat 
tery  process.  The  forms  of  voltaic  bat- 
teries used  are  numerous,  and  in  most 
cases  known  by  the  names  of  their  re- 


kle] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


149 


spective  inventors  ;  such  as  Daniell's, 
Smee's,  and  Grove's  batteries.  The  con- 
stant battery  of  Professor  Daniell  will  be 
found  most  generally  useful ;  it  is  termed 
constant  from  its  possessing  the  power  of 
continuing  in  action  for  any  lengthened 
period  :  it  may  be  made  in  various  forms, 
and  consists  of  a  copper  cell,  divided  into 
two  parts  by  a  porous  diaphragm  or  par- 
tition, which  may  be  formed  of  wood, 
paper,  plaster  of  Paris,  earthenware,  or 
animal  membrane.  The  outer  cell  is 
filled  with  a  saturated  solution  of  sul- 
phate of  copper,  a  perforated  shelf  sup- 
plied with  crystals  of  this  salt  is  placed 
at  the  upper  portion,  as  that  part  of  the 
solution  is  soonest  weakened,  the  spe- 
cific gravity  retaining  the  stronger  por- 
tion below.  The  inner  cell  is  filled  with 
water,  to  which  a  few  drops  of  sulphuric 
acid  are  added,  and  in  which  a  rod  or 
plate  of  amalgamated  zinc  is  placed,  to 
which,  and  to  the  copper  of  the  outer 
cell,  wires  are  attached.  This  battery 
may  be  generally  employed  for  the  pur- 
poses of  plating,  gilding,  and  platinizing, 
and  is  one  of  the  most  economical  modes 
of  reducing  copper.  The  simplest  form  of 
apparatus  used  for  the  deposition  of  me- 
tal, more  particularly  copper,  is  the  single 
cell ;  it  resembles  in  the  number  of  its 
parts  a  Daniell's  battery ;  the  surface  to 
be  deposited  on  repre- 
senting the  copper  of 
the  outer  cell.  The 
diaphragm  may  be 
formed  of  plaster  of 
Paris,  brown  paper,  or 
thin  wood ;  but  the 
action  is  almost  rapid 
when  the  diaphragm 
is  thinnest ;  if  a  mould 
of  metal  or  other  sub- 
stance be  attached  to 
the  zinc  in  the  cell 
containing  the  acid 
and  water,  and  intro- 
duced into  the  sul- 
phate solution,  if  tha 
metallic  communica- 
tion between  the  mould  and  the  zinc  be 
complete,  after  a  short  immersion  the 
former  will  become  coated  with  a  depo- 
sition of  metallic  copper,  which  goes  on 
increasing  in  thickness  as  long  as  the 
strength  of  the  cupreous  solution  is  kept 
up,  which  may  be  done  by  placing  a 
few  crystals^  of  sulphate  in  the  solu- 
tion. Within  a  few  months  past,  mag- 
neto-electric machines  have  been  em- 
ployed for  the  deposition  of  metals  ;  and 
in  Birmingham,  plating  is  carried  on  to  a 


considerable  extent  by  machines,  formed 
by  peculiar  arrangements  of  compound 
magnets,  one  of  which,  lately  manufac- 
tured by  Mr.  Woolrich,  is  capable  of  de- 
positing from  300  to  500  ounces  of  silver 
Ser  week  ;  but  as  such  machines  are  dif- 
cult  in  management,  and  expensive  in 
construction,  they  are  not  well  suited  for 
the  purposes  of  experiment. 

On  the  production  of  Moulds. — Moulds 
may  be  formed  either  of  metallic  or  non- 
metallic  substances ;  in  the  latter  case  it 
is  absolutely  necessary  that  the  surface 
of  the  mould  submitted  for  deposition 
should  be  a  conductor  of  electricity,  and 
the  best  conductors  are  metals  and  car- 
bon. Moulds  for  small  objects,  as  coins 
or  medals,  may  readily  be  made  of  lead 
or  fusible  metal :  a  very  simple  plan  is  to 
place  the  object  between  two  strips  of 
the  former  metal,  scraped  perfectly  clean, 
subjecting  the  whole  to  the  action  of  a 
press.  Moulds  may  be  formed  of  wax, 
stearine,  tallow,  plaster  of  Paris,  sealing 
wax,  &c,  &c. :  the  surfaces  of  either  of 
these  materials  may  be  covered  with  good 
plumbago,  after  fixing  a  metal  wire  into 
the  mould  to  be  deposited  on ;  the  pow- 
der should  be  rubbed  Lghtly  over  with 
a  soft  brush,  taking  care  that  it  adheres 
to  all  parts.  The  deposition  takes  place 
at  the  wire  by  which  the  article  is  con- 
nected with  the  battery  or  cell,  and 
spreads  gradually  from  that  point  till  the 
whole  surface  is  covered ;  but  this  pro- 
cess is  limited  to  the  deposition  of  cop- 
per only,  as  gold  and  silver  will  not 
spread  to  any  extent  on  a  black-leaded 
surface.  Wood  may  be  prepared  to  re- 
ceive a  deposit  in  the  following  manner : 
— The  surface  of  the  block  or  piece  in- 
tended to  be  deposited  on  is  dipped  in  a 
weak  solution  of  nitrate  of  silver,  con- 
tained in  a  flat  vessel,  remaining  for  a 
few  minutes  in  order  that  by  capillary 
attraction  the  nitrate  of  silver  may  be 
drawn  into  the  wood :  a  small  portion  of 
a  solution  of  phosphorus  in  spirits  of 
turpentine  being  poured  into  a  watch- 
glass,  and  placed  on  a  sand-bath,  is  al- 
lowed, gradually  to  evaporate  ;  on  hold- 
ing the  surface  of  the  wood  over  the  va- 
por an  immediate  change  occurs,  the 
nitrate  of  silver  is  converted  into  metallic 
silver,  and  the  object  may  at  once  be 
placed  in  the  battery  to  receive  a  deposit 
of  copper.  In  this  manner  the  interior 
of  a  plaster  mould  may  be  rendered  a 
conductor ;  but  as  this  plan  can  only  be 
adopted  with  substances  which  can  be 
wetted  with  the  solution  of  nitrate  of  sil- 
ver, an  improvement  has  lately  been  in- 


150 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[ele 


troduced,  by  the  adoption  of  a  solution 
of  phosphorus  instead  of  the  vapor  of 
that  substance.  The  best  known  solu- 
tion is  bisulphurct  of  carbon,  which  easily 
dissolves  a  considerable  portion  of  phos- 
phorus. 

If  the  article  to  be  coated  is  dipped  for 
a  moment  in  a  solution  of  one  part  of 
phosphorus  to  twelve  parts  of  bisufphuret 
of  carbon,  on  Avithdrawing  it  the  bisul- 
phuvet  of  carbon,  which  is  very  volatile, 
will  evaporate,  leaving  a  film  of  phos- 
phorus on  the  surface ;  the  article  is  then 
immersed  in  a  dilute  solution  of  nitrate 
of  silver,  or  sulphate  of  copper ;  a  pre- 
cipitate of  silver  or  copper  is  immediately 
formed,  and  thus  becoming  an  electric 
conductor  it  may  be  introduced  into  the 
galvanic  cell,  and  the  process  will  proceed 
in  the  same  manner  as  it  does  when 
plumbago  is  used  in  the  first  instance. 
By  this  simple  and  elegant  method  the 
most  delicate  articles,  as  feathers,  flow- 
ers, fruit,  insects,  &c,  may  be  coated 
with  metal.  The  surface  should  in  all 
case3  be  free  from  moisture  before  it  is 
introduced  into  the  solution  of  phos- 
phorus, which  should  be  used  with  the 
greatest  care,  being  highly  inflammable. 
Phosphorus  added  to  wax  and  stearine 
form  an  excellent  coating  for  casts,  as  the 
surface  becomes  a  conductor.  Moulds  of 
plaster  of  Paris  being  very  porous,  re- 
quire to  be  saturated  with  wax,  oil,  var- 
nish, or  tallow,  before  receiving  a  coating 
of  plumbago,  otherwise  when  placed  in 
the  solution  they  will  absorb  the  liquid, 
and  the  air  which  previously  filled  up  the 
pores  will  be  driven  out,  covering  the 
surface  of  the  mould  with  small  bubbles. 
Flexible  moulds  for  copying  objects  which 
are  undercut,  or  overhung,  may  be  made 
of  a  mixture  of  glue  and  treacle  ;  this 
mixture  is  easily  removed  from  the  pro- 
jecting parts,  immediately  regaining  its 
proper  form. 

The  color  of  bronze  is  given  to  copper 
articles  deposited  by  voltaic  action  by 
different  methods.  A  very  simple  plan 
is  to  rub  the  article  with  plumbago 
immediately,  or  as  soon  as  practica- 
ble, after  its  removal  from  the  battery ; 
afterwards  heating  it,  and  rubbing  it  with 
a  hard  brush.  A  lighter  tint  may  be 
obtained  by  covering  the  surface  with 
oxide  of  iron,  and  giving  it  a  considera- 
ble heat.  Hydrosulphate  of  ammonia 
produces  a  fine  color,  and  a  dilute  solu- 
tion of  chloride  of  platinum  gives  the 
object  an  agreeable  tint. 

On,  Electro- Gilding,  Plating,  Platiniz- 
ing.— The  metals  reduceable  by  voltaic 


agency  for  purposes  of  utility  are  gold,  sil- 
ver, platinum,  copper  and  zinc ;  these  may 
be  precipitated  from  their  salts,  or  from 
the  solutions  of  their  salts  in  any  material 
capable  of  dissolving  them,  and  any  de- 
sired deposit  may  be  made  by  adjusting 
the  strength  and  temperature  of  the  so- 
lution to  the  intensity  and  power  of  the 
current  of  electricity  employed.  Gold 
may  be  deposited  from  its  chloride,  bro- 
mide, cyanide,  iodide,  sulphite,  and  hy- 
posulphite ;  but  for  all  purposes  of  gild- 
ing, it  is  well  to  use  a  solution  of  the 
cyanide,  which  may  be  prepared  by  ad- 
ding oxide  of  gold  to  the  solution  of  cya- 
nide of  potassium.  The  most  eligible 
Proportions  may  be  stated  as  follows : 
'wo  pounds  of  cyanide  of  potassium  dis- 
solved in  one  gallon  of  water,  to  which 
are  added  one  ounce  and  a  half  of  oxide 
of  gold ;  but  if  heat  is  employed,  and 
the  solution  is  raised  to  the  boiling  point, 
the  quantity  of  water  may  be  doubled. 
A  single  pint  battery  of  Daniell's  pos- 
sesses sufficient  intensity  to  gild  any 
specimen,  even  large  ores — the  articles  to 
be  gilt  must  of  course  be  attached  to  the 
zinc  of  the  battery,  and  a  plate  of  gold, 
of  corresponding  or  greater  dimensions, 
to  the  copper.  The  surfaces  of  all  ob- 
jects to  be  gilt,  plated,  or  deposited  on, 
must  be  thoroughly  cleansed  before  being 
introduced  into  the  solution ;  oxide, 
grease,  or  other  impurities,  may  be  re- 
moved by  immersion  in  dilute  sulphuric 
acid.  The  gold  thus  deposited  may  be 
colored  to  produce  the  red  tint  so  gene- 
rally admired,  by  being  coated  with  a 
mixture  of  acetate  of  copper,  sulphate  of 
alumina,  and  bees'-wax,  and  exposed  to 
heat  till  the  whole  is  consumed ;  and  a 
rich  orange  color  may  be  obtained  by 
gently  boiling  the  following  ingredients 
together  in  water  till  they  have  a  creamy 
consistency :— Five  parts  of  nitrate  o'f 
potassa,  two  parts  of  sulphate  of  alumina, 
one  part  of  sulphate  of  zinc,  and  one  part 
of  sulphate  ot  iron.  The  gilt  object 
should  then  be  dipped  three  or  four 
times  in  the  composition,  and  allowed  to 
become  nearly  dry,  and  afterwards  re- 
moved to  a  stove,  when,  according  to  the 
length  of  exposure  to  heat  the  depth  of 
color  will  be  increased  :  it  should  finally 
be  well  washed,  and  cleaned  with  soap 
and  water  and  a  brush. 

Silver  can  be  precipitated  from  its  cya- 
nide, acetate,  sulphate,  sulphite,  or  hypo- 
sulphite solutions.  A  solution  of  one 
pound  and  a  half  of  cyanide  of  potassium  in 
one  gallon  of  water,  to  which  two  ounces 
of  oxide  of  silver  are  abided,  answers  ad- 


eleJ 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


151 


mirably  for  all  purposes  of  plating.    For 
some  time  after  the  introduction  of  elec- 
tro-gilding and  plating,  complaints  were 
made  of  defective  adhesion  between  the 
original  and  the  deposited  metal,  and  it 
was  asserted  by  the    manufacturers   of 
similar  articles  on  the  old  principle,  that 
such  plating  and  gilding    would    soon 
wear  away,  and  exhibit  the  baser  metal 
in  all  its  original  nakedness.    There  was, 
it  must  be  admitted,    some  justice  in 
this  remark,  though  articles  plated  three 
years  ago  have  been  in  daily  use  without 
showing  any  traces  of  the  copper  beneath. 
This  defect  was  occasioned  by  the  ab- 
sence of  an  alloy,  but  the  objection  has 
lately  been  altogether  removed   by  the 
use  of  mercury,  for  the  purpose  of  alloy- 
ing the  two  metallic  surfaces  ;   for  this 
purpose,  nitrate  of  mercury  is  dissolved 
in  water,  and  the  copper  article  to  be  gilt 
or  plated  is  plunged  in  the  solution,  and 
immediately  withdrawn,  then  washed  in 
water,  and  placed  in  the  gold  or  silver 
solution.     A  thin  film  of  mercury  is  by 
this  means  distributed  over  the  object, 
and    amalgamating    with    both    metals, 
completely   alloys   them.       The    articles 
after  being  gilt  or  silvered   should  be 
heated  to  600°  Fahr.,   which  dissipates 
the  mercury.   Another  complaint  against 
electro-plating  was,  that  the  articles  ra- 
pidly tarnished  on  account  of  the  purity 
of  the-  metal  deposited.     This  may  be 
obviated  by  brushing  them  over  after  re- 
moval from  the  vat  with  a  saturated  so- 
lution of  biborate  of  soda,  allowing  them 
to  dry  so  that  a  film  of  the  salt  may  re- 
main, repeating  the  process  a  second  or 
third  time,  till  a  slight  but  regular  coat- 
ing of  borax  covers  every  part ;    they 
should  then  be  exposed  to  a  red  heat, 
and  after  being  allowed  to  cool,  immersed 
in   dilute   sulphuric  acid,    and  dried   in 
heated  saw-dust.     The  metals-  to  which 
plating  are  most  applicable  are  copper, 
brass,  pewter,  iron,  steel,  and  erold  ;  the 
process  is  also  extensively  employed  for 
severing  articles  formed  "of  the  alloy  of 
nickel,  known  as  German  silver. 
-.  Platinum  may  be  reduced  from  solu- 
tions of  its  bromide,  iodide,  and  bi-chlo- 
ride,  and  the  double  chloride  of  platinum 
and  sodium.     The  chloride  is  the   salt- 
commonly  employed,  but  as  considerable 
difficulty  exists  in  depositing  this  metal 
in  a  ductile  state,  a  very  feeble  current 
of  electricity  should  be   employed,  and 
the  plate  of  metal  introduced  as  an  elec- 
trode should  be  very  small ;  it  is  of  great 
advantage  to  have  the  solution  neutral, 
and  some  therefore  recommend  soda  be- 


'  ing  added  to  it,  thus  forming  the  chic- 
;  ride  of  sodium  and  platinum. 

Zinc  may  be  deposited  from  its  iodide, 
I  acetate,  sulphate,  and  chloride ;  also  from 
i  the  solution  of  oxide  of  zinc  in  potassa,  or 
muriate  of  ammonia. 

Copper  may  be  thrown  down  from  a 
considerable  range  of  its  salts ;  those 
commonly  used  are  the  sulphate,  nitrate, 
and  cyanfde. 

Probably  the  most  enormous  applica- 
tion of  the  electrotype  art  is  made  in  the 
sculpture  of  the  Cathedral  of  St.  Isaac  in 
Petersburgh.  Seven  doors  of  the  ca- 
thedral are  of  bronze  and  electrotype,  the 
framework  being  of  the  former  "and  the 
scultured  posts  of  the  latter.  Three  of 
these  doors  are  30  feet  high  and  44  feet 
wide,  the  four  others  17  feet  8  inches 
wide.  They  contain  51  bas  reliefs,  63 
statuettes,  and  84  alto  relievo  bvsts  of 
religious  subjects.  The  gilding  of  tht  ca- 
thedral was  also  done  by  this  process. 
The  quantity  of  metal  employed  in  the 
dome  was  as  follows : — Ducat  gold,  247 
lbs. ;  copper,  521  tons  ;  brass,  32l£  tons  ; 
wrought  iron,  5241  tons ;  cast  iron,  1068 
tons  ;  total,  1,966s  tons.  Casts  in  cop- 
per have  been  taken  from  the  daguerreo- 
type plate,  and  impressions  from  these 
casts  produced  by  electrotype  by  Dr. 
Paterson  of  Glasgow,  Scotland.  Smooth 
as  a  daguerreotype  appears,  the  cast 
taken  serves  as  a  mould  from  which  al- 
most any  number  of  impressions  may  be 
taken,  which  are  as  bold  and  as  clear  as 
the  original  type. 

EL  EMI  is  a  resin  which  exudes  from  in- 
cisions made  during  dry  weather  through 
the  bark  of  the  amyris  etimifera,  a  tree 
which  grows  in  South  America  and  Bra- 
zil. It  comes  to  us  in  yellow,  tender, 
transparent  lumps,  which  readily  soften 
by  the  heat  of  the  hand.  They  have  a 
strong  aromatic  odor,  a  hot  spicy  taste, 
and  contain  12?  per  cent,  ot  ethereal 
oil.  The  crystalline  resin  of  elemi  has 
been  called  Elemine.  It  is  used  in  mak- 
ing lacker,  to  give  toughness  to  the  var- 
nish. 

ELEMENTS.  The  ancients  consider- 
ed fire,  air,  water,  and  earth,  as  simple 
substances,  essential  to  the  constitution 
of  all  terrestrial  beings.  This  hypothe- 
sis, evidently  incompatible  with  modern 
chemical  discovery,  may  be  supposed  to 
correspond,  however,  'to  the  four  states 
in  which  matter  seems  to  exist ;  namely, 
1st,  the  unconfinable  powers  of  fluids — 
caloric,  light,  electricity ;  2d,  ponderable 
gases,  or  elastic  fluids  ;  3d,  liquids;  4th, 
solids.      The  three  elements  of  the  al- 


152 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[' 


chemists,  salt,  earth,  mercury,  were,  in 
their  sense  of  the  word,  mere  phantasms. 

EMBALMING.  A  process  adopted 
by  the  ancient  Egyptians,  chiefly  for  the 
preservation  of  dead  bodies  from  putre- 
faction. The  term  is  derived  from  the 
use  of  balsamic  substances  in  the  opera- 
tion ;  in  addition  to  these,  saline  sub- 
stances and  tanning  materials  seem  also 
to  have  been  used. 

EMBANKMENT.  In  territorial  im- 
provement, an  embankment  is  a  mound 
of  earth  or  a  wall,  or  a  structure  com- 
posed partly  of  a  wall  or  partly  of  a  bank 
of  earth,  to  protect  lands  from  being 
overflown  by  rivers  or  the  sea.  Em- 
bankments appear  to  have  been  coeval 
with  the  culture  of  corn  crops  ;  because 
these,  it  appears,  were  first  grown  on  the 
alluvial  soils  which  border  large  rivers, 
and  to  protect  the  crops  from  the  over- 
flowing of  these  rivers  after  heavy  or 
long-continued  rains,  the  cultivator  would 
naturally  throw  up  a  bank  of  earth.  This 
appears  to  have  Deen  done  in  Egypt  at 
the  most  remote  period  of  which  there  is 
any  record.  In  modern  times,  embank- 
ments are  employed,  not  merely  to  pro- 
tect land  under  cultivation,  but  to  en- 
close land  that  is  occasionally  overflown 
by  rivers  or  the  sea,  and  render  it  fit  for 
the  purposes  of  husbandry.  This  has 
been  done  to  a  greater  extent  in  Holland 
than  in  any  other  country.  There  are 
also  immense  embankments  in  Italy,  par- 
ticularly in  Lombardy.  In  Britain,  there 
are  the  embankments  of  the  Thames 
near  London,  which  have  been  in  exist- 
ence since  the  time  of  the  Komans  ; 
many  in  Lincolnshire,  formed  during  the 
time  of  Cromwell,  and  some  of  them 
many  centuries  before  ;  and  one  of  the 
most  recent  is  that  at  Tre  Madoc  in  Caer- 
narvonshire, by  which  upwards  of  4000 
acres  were  recovered  from  spring  tides, 
and  in  great  part  rendered  fit  for  the 
plough.  Embankments  are  attended 
with  immense  expense ;  but  as  the  soil 
gained  or  protected  is  generally  of  the 
best  quality,  a  judicious  embankment  is 
commonly"  considered  as  paying  about 
the  same  rate  of  interest  as  a  landed 
estate.  The  levees  of  the  Mississippi  are 
numerous  examples. 

EMBOSSING  WOOD.  Raised  figures 
upon  wood,  such  as  are  employed  in  pic- 
ture-frames and  other  articles  of  orna- 
mental cabinet  work,  are  usually  pro- 
duced by  means  of  carving,  or  by  casting 
the  pattern  in  plaster  of  Paris,  or  other 
composition,  and  cementing,  or  other- 
wise fixing  it  on  the  surface  of  the  wood. 


The  former  mode  is  expensive  ;  the  lat- 
ter is  inapplicable  on  many  occasions. 
The  invention  of  Mr.  Streaker  may  be 
used  either  by  itself,  or  in  aid  of  carv- 
ing ,  and  depends  on  the  fact,  that  if  a 
depression  be  made  by  a  blunt  instru- 
ment on  the  surface  of  the  wood,  such 
depressed  part  will  again  rise  to  its  ori- 
ginal level  by  subsequent  immersion  in 
the  water. 

The  wood  to  be  ornamented  having 
been  first  worked  out  to  its  propos- 
ed shape,  is  in  a  state  to  receive  the 
drawing  of  the  pattern ;  this  being  put 
on,  a  blunt  steel  tool,  or  burnie?er,  or 
die,  is  to  be  applied  successively  to  all 
those  parts  of  the  pattern  intended,  to  be 
in  relief,  and,  at  the  same  time,  is  to  be 
driven  very  cautiously,  without  breaking 
the  grain  of  the  wood,  till  the  depth  of 
the  depression  is  equal  to  the  intended 
prominence  of  the  figures.  The  ground 
is  then  to  be  reduced  by  planing  or  filing 
to  the  level  of  the  depressed  part ;  after 
which,  the  piece  of  wood  being  placed  in 
water,  either  hot  or  cold,  the  part  pre- 
viously depressed  will  rise  to  its  former 
height,  and  will  then  form  an  embossed 
pattern,  which  may  be  finished  by  the 
usual  operations  of  carving. 

EMBROIDERY.  The  name  given  to 
the  art  of  working  figures  on  stuffs  or 
muslins  with  a  needle  and  thread.  All 
embroider}'  may  be  divided  into  two 
sorts,  embroidery  on  stuffs  and^  on  mus- 
lin :  the  former  is  used  chiefly  in  church 
vestments,  housings,  standards,  articles 
of  furniture,  &c,  and  is  executed  with 
silk,  cotton,  wool,  gold  and  silver  threads, 
and  sometimes  ornamented  with  span- 
gles, real  or  mock  pearls,  precious  or 
imitation  stones,  &c. ;  the  latter  is  em- 
ployed mostly  in  articles  of  female  appa- 
rel, as  caps,  collars,  &c,  and  is  perform- 
ed only  with  cotton.  In  Germany  this 
division  is  indicated  by  the  expression 
weisse  hvhite  or  muslin),  and  bunte  Sticke- 
rei  (colored  or  cloth)  embroidery.  Th# 
embroidery  of  stuffs  is  performed  on  a 
kind  of  loom  or  frame  ;  that  of  muslin 
by  stretching  it  on  a  pattern  already  de- 
signed. The  modes  of  embroidering 
stuffs  or  muslin  with  the  common  needle 
are  extremely  various  ;  but  a  minute  de- 
scription of  these  processes  would  be  as 
difficult  as  it  would  be  uninteresting  to 
the  general  reader.  They  consist  for  the 
most  part  of  a  combination  of  ordinary 
stitches  ;  but  no  limit  can  be  assigned  to 
their  number  or  variety.  The  art  of  em- 
broidery was  well  known  to  the  ancients. 
As  early  as  the  time  of  Mobcs  we  find  it 


EMP] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


153 


practised  successfully  by  the  Hebrews  ; 
and  long  before  the  Trojan  war  the  wo- 
men of  Sidon  had  acquired  celebrity  for 
their  skill  in  embroidery.  At  a  later  pe- 
riod, this  art  was  introduced  into  Greece, 
probably  by  the  Phrygians  ^by  some 
considered  the  inventors)  ;  and  to  such  a 
degree  of  skill  did  the  Grecian  women 
attain  in  it,  that  their  performances  were 
said  to  rival  the  finest  paintings.  In  our 
own  times  the  art  of  embroidery  has 
been  cultivated  with  great  success,  more 
especially  in  Germany  and  France  ;  and 
though  for  a  long  period  it  was  practised 
only  by  the  ladies  of  these  countries  as  an 
elegant  accomplishment,  it  is  now  regard- 
ed as  a  staple  of  traffic,  and  furnishes  em- 
ployment for  a  large  portion  of  the  popu- 
lation. 

EMBROIDEEING  MACHINE.  This 
art  has  been  till  of  late  merely  a  handi- 
craft employment,  cultivated  on  account 
of  its  elegance  by  ladies  of  rank.  But  a 
few  years  ago  M.  Heilmann  of  Mulhause 
invented  a  machine  of  a  most  ingenious 
kind,  which  enables  a  female  to  em- 
broider any  design  with  80  or  140  nee- 
dles as  accurately  and  expeditiously  as 
she  could  formerly  do  with  one.  A  brief 
account  of  this  remarkable  invention  will 
therefore  be  acceptable  to  many  readers. 
It  was  displayed  at  the  national  expo- 
sition of  the  products  of  industry  in  Paris 
for  1834,  and  was  unquestionably  the 
object  which  stood  highest  in  public 
esteem  ;  for  whether  at  rest  or  in  motion, 
it  was  always  surrounded  with  a  crowd 
of  curious  visitors,  admiring  the  figures 
which  it  had  formed,  or  inspecting  its 
movements  and  investigating  its  mecha- 
nism. 130  needles  were  occupied  in 
copying  the  same  pattern  with  perfect 
regularity,  all  set  in  motion  by  one  person. 

Several  of  these  machines  are  now 
mounted  in  France,  Germany,  and  Swit- 
zerland. There  exists  one  factory  in  Man- 
chester, where  a  great  many  of  them  are 
doing  beautiful  work. 

The  price  of  a  machine  having  130  nee- 
dles, and  of  consequence  260  pincers  or 
fingers  and  thumbs  to  lay  hold  of  them, 
is  5000  francs,  or  £200  sterling ;  and  it 
is  estimated  to  do  daily  the  work  of  15 
expert  hand  embroiderers,  employed  upon 
the  ordinary  frame.  It  requires  merely 
the  labor  of  one  grown-up  person,  and 
two  assistant  children.  The  operative 
must  be  well  taught  to  use  the  machine, 
for  he  has  many  things  to  attend  to ; 
with  the  one  hand  he  traces  out,  or  rather 
follows  the  design  with  the  point  of  the 
pentograph  ;  with  the  other  he  turns  a 
7* 


handle  to  plant  and  pull  all  the  needles, 
which  are  seized  by  pincers  and  moved 
along  by  carriages,  approaching  to  and 
receding  from  the  web,  rolling  all  the 
time  along  an  iron  railway ;  lastly,  by 
means  of  two  pedals,  upon  which  he 
presses  alternately  with  one  foot  and  the 
other,  he  opens  the  130  pincers  of  the 
first  carriage,  which  ought  to  give  up  the 
needles  after  planting  them  in  the  stuff, 
and  he  shuts  with  the  same  pressure  the 
130  pincers  of  the  second  carriage,  which 
is  to  receive  the  needles,  to  draw  them 
from  the  other  side?  and  to  bring  them 
back  again.  The  children  have  nothing 
else  to  do  than  to  change  the  needles 
when  all  their  threads  are  used,  and  to 
see  that  no  needle  misses  its  pincers. 

EMEE  ALD.  A  mineral  of  a  beautiful 
green  color,  which  occurs  in  prismatic 
crystals,  and  is  much  valued  for  orna- 
mental jewelry.  The  finest  are  obtain- 
ed from  Peru.  It  consists  of  65  silica, 
16  alumina,  13  glucina,  about  3  oxide  of 
chromium  (which  is  the  coloring  matter), 
and  a  trace  of  lime.  The  mines  from 
which  the  ancients  obtained  emeralds  are 
said  to  have  existed  in  Egypt,  near  Mount 
Zabarah. 

EMEEY.  (From  Cape  Emeri,  in  the 
island  of  Naxos.)  A  variety  of  corun- 
dum ;  amorphous,  compact,  and  gene- 
rally opaque.  It  is  characterized  by  ex- 
cessive hardness  ;  and  its  powder  is  used 
for  cutting  and  polishing  glass,  gems,  and 
all  hard  substances :  it  scratches  and 
wears  down  nearly  all  minerals  except  the 
diamond. 

EMETIC  TAETAE.  A  triple  salt, 
composed  of  oxide  of  antimony,  potassa, 
and  tartaric  acid.  It  is  soluble  in  eigh- 
teen parts  of  cold  and  in  three  of  boiling 
water.  In  the  dose  of  from  half  a  grain 
to  two  grains  it  operates  as  a  powerful 
emetic  and  sudorific ;  in  smaller  doses, 
it  acts  upon  the  bowels,  and  is  diapho- 
retic. 

EMETINE.  A  substance  discovered 
in  1817  by  Pelletier  in  ipecacuanha.  It 
is  white,  pulverulent,  and  bitter ;  easily 
soluble  in  hot  water  and  alcohol,  and  in- 
tensely emetic.  It  exists  in  ipecacuanha 
to  the  amount  of  about  16  per  cent.,  and 
appears  to  be  the  sole  cause  of  its  emetic 
property. 

EMPYEEUMA  means  the  offensive 
smell  produced  by  fire  applied  to  organic 
matters,  chiefly  vegetable,  in  close  ves- 
sels. Thus,  empyreumatic  vinegar  is 
obtained  by  distilling  wood  at  a  red  heat, 
and  empyreumatic  osil  from  many  animal 
substances  in  the  same  way. 


154 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[ena 


ENAMELS  are  varieties  of  glass,  gene- 
rally opaque  and  colored,  always  formed 
by  the  combination  of  different  metallic 
oxides,  to  which  certain  fixed  fusible  salts 
are  added,  such  as  the  borates,  fluates, 
and  phosphates. 

The  simplest  enamel,  and  the  one  which 
serves  as  a  basis  to  most  of  the  others,  is 
obtained  by  calcining  first  of  all  a  mix- 
ture of  lead  and  tin,  in  proportions  vary- 
ing from  15  to  50  parts  of  tin  for  100  of 
lead.  The  _  middle  term  appears  to  be 
the  most  suitable  for  the  greater  number 
of  enamels ;  and  this  alloy  has  such  an 
affinity  for  oxygen,  that  it  may  be  cal- 
cined with  the  greatest  ease  in  a  flat  cast- 
iron  pot,  and  at  a  temperature  not  above 
a  cherry  red,  provided  the  dose  of  tin  is 
not  too  great.  The  oxide  is  drawn  off  to 
the  sides  of  the  melted  metal  according 
as  it  is  generated,  new  pieces  of  the  alloy 
being  thrown  in  from  time  to  time  till 
enough  of  the  powder  be  obtained. 
Great  care  ought  to  be  taken  that  no  me- 
tallic particles  be  left  in  the  oxide,  and 
that  the  calcining  heat  be  as  low  as  is 
barely  sufficient ;  for  a  strong  fire  frits 
the  powder,  and  obstructs  its  subsequent 
comminution.  The  powder  when  cold  is 
ground  in  a  proper  mill,  levigated  with 
water,  and  elutriated,  as  will  be  described, 
under  lied  lead.  In  this  state  of  fineness 
and  purity,  it  is  called  calcine,  or  flux, 
and  it  is  mixed  with  silicious  sand  and 
some  alkaline  matter  or  sea-salt.  The 
most  ordinary  proportions  are,  4  of  sand, 
1  of  sea-salt,  and  4  of  calcine.  Chaptal 
states  that  he  has  obtained  a  very  fine 

Eroduct  from  100  parts  of  calcine,  made 
y  calcining  equal  parts  of  lead  and  tin, 
100  parts  of  ground  flint,  and  200  parts 
of  pure  subcarbonate  of  potash.  In 
either  case,  the  mixture  is  put  into  a 
crucible,  or  laid  simply  on  a  stratum  of 
sand,  quicklime  spontaneously  slaked, 
or  wood-ashes,  placed  under  a  pottery  or 
porcelain  kiln.  This  mass  undergoes  a 
semi-vitrification  ;  or  even  a  complete 
fusion  on  its  surface.  It  is  this  kind  of 
frit  which  serves  as  a  radical  to  almost 
every  enamel ;  and  by  varying  the  pro- 
portions of  the  ingredient,  more  fusible, 
more  opaque,  or  whiter  enamels  are  ob- 
tained. The  first  of  these  qualities  de- 
pends on  the  quantity  of  sand  or  flux, 
and  the  other  two  on  that  of  the  tin. 

The  sea-salt  employed  as  a  flux  may 
be  replaced  either  by  salt  of  tartar,  by 
pure  potash,  or  by  soda;  but  each  of 
these  fluxes  gives  peculiar  qualities  to 
the  enamel. 
A  patent  was  granted  to  Thomas  and 


Charles  Clarke,  of  England,  in  1839,  for 
a  method  of  enamelling  or  coating  the  in- 
ternal surfaces  of  iron  pots  and  sauce- 
pans, in  such  a  way  as  shall  prevent  the 
enamel  from  cracking  or  splitting  off  from 
the  effects  of  fire.  The  specification 
prescribes  the  vessel  to  be  first  cleansed 
by  exposing  it  to  the  action  of  dilute  sul- 
phuric acid,  (sensibly  sour  to  the  taste) 
for  three  or  four  hours,  then  boiling  the 
vessel  in  pure  water  for  a  short  time,  and 
next  applying  the  composition.  This 
consists  of  100  lbs.  of  calcined  ground 
flints ;  50  lbs.  of  borax  calcined,  and 
finely  ground  with  the  above.  That 
mixture  is  to  be  fused  and  gradually 
cooled. 

40  lbs.  weight  of  tbe  above  product  is 
to  be  taken  with  5  lbs.  weight  of  potter's 
clay ;  to  be  ground  together  in  water 
until  the  mixture  forms  a  pasty-consis- 
tenced  mass,  which  will  leave  or  form  a 
coat  on  the  inner  surface  of  the  vessel 
about  one-sixth  of  an  inch  thick.  When 
this  coat  is  set,  by  placing  the  vessel  in 
a  warm  room,  the  second  composition  is 
to  be  applied.  This  consists  of  125  lbs. 
of  white  glass  (without  lead),  25  lbs.  of 
borax,  20 lbs.  of  soda  (crystals),  all  pul- 
verized together  and  vitrified  by  fusion, 
then  ground,  cooled  in  water,  and  dried. 
To  45  lbs.  of  that  mixture,  1  lb.  of  soda 
is  to  be  added,  the  whole  mixed  together 
in  hot  water,  and  when  dry.  pounded; 
then  sifted  finely  and  evenly  over  the 
internal  surface  of  the  vessel  previously 
covered  with  the  first  coating  or  compo- 
sition, while  this  is  still  moist.  This  is 
the  glazing.  The  vessel  thus  prepared 
is  to  be  put  into  a  stove,  and  dried  at 
the  temperature  of  212°  Fahr.  It  is  then 
heated  in  a  kiln  or  muffile,  like  that  used 
for  glazing  china.  The  kiln  being  brought 
to  its  full  heat,  the  vessel  is  placed  first 
at  its  mouth  to  heat  it  gradually,  and 
then  put  into  the  interior  of  the  infusion 
of  the  glaze.  In  practice  it  has  been 
found  advantageous  also  to  dust  the 
glaze  powder  over  the  fused  glaze,  and 
apply  a  second  fluxing  heat  in  the  oven. 
The  enamel,  by  this  double  application, 
becomes  much  smoother  and  sounder. 

ENAMEL,  foe  Pins,  Hooks  and  Eyes, 
&c.  The  articles  to  be  enamelled,  after 
being  thoroughly  cleaned  and  freed  from 
dust  and  dirt  are  spread  or  placed  in  a 
basin,  dish,  or  other  fit  receptacle,  where 
they  are  wetted  with  the  spirit  or  oil  of 
turpentine ;  they  are  then  dried,  if  re- 
quired, by  artificial  means :  when  dry, 
the  enamel  or  japan  is  applied,  it  tak- 
ing effect  and  spreading  a  coat  upon  the 


EQU] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


155 


whole  of  those  parts  of  the  articles  pre- 
viously covered  by  the  turpentine ;  should 
it  be  required  to  give  the  articles  more 
coats  than  one,  the  same  process  of  ap- 
plying the  enamel  is  to  be  repeated,  but 
omitting  to  apply  the  spirit  of  turpen- 
tine. The  compositions  are  as  follows : 
for  blue,  the  best  varnish  or  gums,  three 
quarters  of  a  pint-  of  spirits  of  turpen- 
tine, half  a  pint;  flake  white,  1  lb.,  and 
prussiate  of  iron,  1  oz.  For  red,  Per- 
sian vandyke,  1  lb. ;  varnish  or  gums, 
half  a  pint;  spirits  of  turpentine,  quar- 
ter of  a  pint.  For  green,  pale  chrome, 
|  lb. ;  varnish  or  gums,  half  a  pint;  spi- 
rits of  turpentine,  quarter  of  a  pint. 
Other  colors  or  tints  may  be  composed 
and  applied  in  like  manner  by  varying 
or  altering  the  proportions  of  the  mate- 
rials. 

ENCAUSTIC  PAINTING.  In  paint- 
ing, a  method  of  painting  used  by  the 
ancients,  the  precise  mode  of  executing 
■which  is  by  no  means  sufficiently  ex- 
plained. From  Pliny's  account,  it  seems 
that  the  colors  were  made  up  into  cray- 
ons through  a  medium  of  wax,  and,  the 
subject  being  previously  traced  with  a 
metal  point,  were  melted  on  the  picture 
as  they  were  used.  The  picture  being 
finished,  a  varnish  of  melted  wax  was 
spread  over  all.  The  colors  thus  not 
only  obtained  considerable  brilliancy,  but 
the  work  was  also  protected  from  the 
weather.  It  was  lastly  well  polished. 
The  attempts  to  revive  this  art,  which, 
after  all,  if  we  may  draw  our  conclusion 
from  Pliny's  account,  seems  to  have  been 
but  a  clumsy  process,  have  not  been  at- 
tended with  success. 

EQUATOK1AL.  An  astronomical  in- 
strument, contrived  for  the  purpose  of 
directing  a  telescope  upon  any  celestial 
object  of  which  the  right  ascension  and 
declination  are  known,  and  of  keeping 
the  object  in  view  for  any  length  of  time, 
notwithstanding  the  diurnal  motion.  For 
these ^purposes,  a  principal 
axis  (J  D,  resting  on  firm 
supports,  is  placed  parallel 
to  the  axis  of  the  earth's 
rotation,  and  consequently 
pointing  to  the  poles  of  the 
heavens.  On  this  polar 
axis  there  is  fixed,  near 
one  of  its  extremities,  a 
graduated  circle  A  B,  the 
plane  of  which  is  perpen- 
dicular to  the  polar  axis, 
and  therefore  parallel  to  the  earth's  equa- 
tor. This  circle  is  called  the  equatmnal 
circle,  and  measures  by  its  arcs  the  hour 


angles,  or  differences  of  right  ascension. 
The  polar  axis  is  pierced  at  E  F,  and 
penetrated  by  the  axis  of  a  second  circle 
G  II,  at  right  angles  to  it.  The  axis  of 
the  second  circle  has  consequently  no 
connection  with  any  external  support, 
but  is  sustained  entirely  by  the  polar 
axis.  The  plane  of  the  second  circle 
G  H,  which  is  called  the  declination,  cir- 
cle, and  carries  the  telescope  K,  is  thus 
in  all  positions  at  right  angles  to  the 
plane  of  the  first  or  equatorial  circle  A  B. 
Now  it  is  easy  to  conceive,  from  this 
general  description,  that  when  the  tele- 
scope is  pointed  to  a  star,  the  angle  be- 
tween the  direction  of  the  telescope  and 
the  polar  axis  is  equal  to  the  polar  dis- 
tance of  the  star ;  consequently,  when  a 
motion  is  given  to  the  polar  axis  without 
altering  the  position  of  the  telescope  on 
the  declination  circle,  the  point  to  which 
the  telescope  is  directed  will  always  lie 
in  the  small  circle  of  the  heavens  coinci- 
dent with  the  star's  diurnal  path ;  and 
hence,  if  the  motion  communicated  to 
the  polar  axis  be  just  equal  to  the  earth's 
diurnal  rotation,  the  star  will  remain 
constantly,  and  as  long  as  we  please,  in 
the  field  of  the  telescope,  at  least  while 
above  the  horizon.  In  many  observa- 
tions this  is  indispensable,  and  it  is  an 
advantage  which  attaches  to  no  other  in- 
strument. The  polar  axis  may  be  moved 
by  a  peculiar  kind  of  clock  machinery, 
adjusted  to  sidereal  time ;  and  the  best 
and  largest  equatorials  are  now  furnished 
with  such  an  apparatus.  Besides  reliev- 
ing the  observer  from  the  fatigue  of 
turning  the  instrument,  the  motion  thus 
given  "is  perfectly  equable,  and  all  those 
jerks  avoided  which,  when  the  instru- 
ment is  turned  by  the  hand,  often  prove 
fatal  to  an  observation. 

EQUIVALENTS,  CHEMICAL.  A 
term  introduced  into  chemistry  by  Dr. 
Wollaston  to  express  the  system  of  defi- 
nite ratios  in  which  substances  recipro- 
cally combine,  referred  to  a  common 
standard  of  unity.  If  we  assume  hydro- 
gen as  unity,  it  being  the  substance 
which  combines  with  others  in  the  smal- 
lest relative  weight  or  proportions,  then 
all  other  substances  may  be  represented 
by  certain  multiples  of  that  unit,  ex- 
pressed with  sufficient  precision  for  all 
ordinary  purposes  by  whole  numbers. 
Thus,  upon  this  system,  the  equivalent 
number  of  oxygen  will  be  8,  and  that  of 
water  will  be  'J,  for  8  oxygen  + 1  hydro- 
gen =  9  water ;  and  the  equivalent  of 
potassium  will  be  40,  and  of  potassa  or 
oxide  of  potassium  48,  for  40  potassium 


156 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[eng 


+  8  oxygen  =  48  potassa.  Upon  the  same 
principle  the  equivalent  of  hydrochloric 
acid,  which  is  a  compound  of  chlorine 
and  hydrogen,  is  37,  for  it  consists  of  1 
part  by  weight  of  hydrogen  and  36  of 
chlorine;  or,  in  other  words,  of  an  atom 
of  hydrogen  =  1  +  an  atom  of  chlorine 
=  36.  The  equivalent  of  sulphur  is  16  : 
to  form  sulphuric  acid  one  atom  of  sul- 
phur =  16  combines  with  3  atoms  of  oxy- 
gen (8  X  3)  =  24  ;  hence  the  equivalent 
of  an  atom  of  sulphuric  acid  is  16  +  24 
=  40.  These  equivalents  are  often  ex- 
pressed by  certain  abbreviations,  termed 
chemical  symbols  ;  which,  as  far  as  single 
equivalents  of  the  simple  substances  are 
concerned,  are  represented,  together  with 
their  equivalent  numbers,  in  a  table  in 
the  article  Atom. 

ENGKAVING  ON  WOOD,  or  Xy- 
lography. In'this  branch  of  art  the  ma- 
terial used  is  a  block  of  box  or  pear-tree 
wood,  cut  at  right  angles  to  the  direction 
of  the  fibres,  the  thickness  being  regu- 
lated by  the  height  of  the  type  in  the 
form.  The  subject  is  either  transferred 
from  a  previous  print,  or  else  drawn  on 
the  block  with  a  black  lead  pencil,  or 
with  Indian  ink.  The  whole  of  the  wood 
is  then  cut  away  except  where  the  lines 
are  drawn,  which  are  left  as  raised  parts. 
In  this  it  differs  from  copper-plate  en- 
graving, where  the  lines  are  cut  out,  or 
sunk  m  the  metal.  The  impressions 
from  wood  blocks  are  taken  in  the  same 
manner  as  from  printing  types. 

Copper  Engraving  is  performed  by 
cutting  lines  representing  the  subject  on 
a  copper  plate  with  a  steel  instrument, 
ending  in  an  unequal  sided  pyramidal 
point,  such  instrument  being  called  a 
graver,  or  burin,  without  the  use  of 
aquafortis :  which  mode  is  described 
further  on.  Besides  the  graver  there 
are  other  instruments  used  in  the  pro- 
cess, viz.,  a  scraper,  a  burnisher,  an  oil 
stone,  and  a  cushion  for  supporting  the 
plate.  In  cutting  the  lines  on  the  copper 
the  graver  is  pushed  forward  in  the  di- 
rection required,  being  held  in  the  hand 
at  a  small  inclination  to  the  plane  of  the 
copper.  The  use  of  the  burnisher  is  to 
soften  down  lines  that  are  cut  too  deep, 
and  for  burnishing  out  scratches  in  the 
copper:  it  is  about  three  inches  long. 
The  scraper,  like  the  last,  is  of  steel, 
with  three  sharp  edges  to  it,  and  about 
six  inches  lontr,  tapering  towards  the 
end.  Its  use  is  to  scrape  off  the  burr, 
raised  by  the  action  of  the  graver.  To 
show  the  appearance  of  the  work  dur- 
ing its  progress,  and  to  polish  off  the 


burr,  engravers  use  a  roll  of  woollen  oi 
felt  called  a  rubber,  which  is  put  in  ac- 
tion with  a  little  olive  oil.  The  cushion, 
which  is  a  leather  bag  about  nine  inches 
diameter  filled  with  sand  for  laying  the 
plate  on,  is  now  rarely  used  except  by 
writing  engravers.  Eor  architectural 
subjects,  or  in  skies,  where  a  series  of 
parallel  lines  are  wanted,  an  ingenious 
machine  was  invented  by  the  late  Mr. 
Wilson  Lowry,  called  a  ruling  machine, 
the  accuracy  of  whose  operation  is  ex- 
ceedingly perfect.  This  is  made  to  act 
on  an  etching  ground  by  a  point  or  knife 
connected  with  the  apparatus,  and  bit  in 
with  aquafortis  in  the  ordinary  way. 

Etching  is  a  species  of  engraving  on 
copper  or  other  metals  with  a  sharp  point- 
ed instrument  called  an  etching  needle. 
The  plate  is  covered  with  a  ground  or 
varnish  capable  of  resisting  the  action  of 
aquafortis.  The  usual  method  is  to  draw 
the  design  on  paper  with  a  black-lead 
pencil ;  the  paper  being  damped  and  laid 
upon  the  plate,  prepared  as  above,  with 
the  drawing  next  the  etching  ground,  is 
passed  through  the  rolling  press,  and 
thus  the  design  is  transferred  from  the 
paper  to  the  ground.  The  needle  then 
scratches  out  the  lines  of  the  design ;  and 
aquafortis  being  poured  over  the  plate, 
which  is  bordered  round  with  wax,  it 
is  allowed  to  remain  on  it  long  enough 
to  corrode  or  bite  in  the  lines  which  the 
etching  needle  has  made.  Etching  with 
a  dry  point,  as  it  is  called,  is  performed 
entirely  with  the  point  without  any 
ground,  the  burr  raised  being  taken  off 
by  the  scraper.  Etching  with  a  soft 
ground  is  used  to  imitate  chalk  or  black- 
lead  drawings.  For  this  purpose  the 
ground  is  mixed  with  a  portion  of  tallow 
or  lard,  according  to  the  temperature  of 
the  air.  A  piece  of  thin  paper  being  at- 
tached to  the  plate  at  the  tour  corners  by 
some  turner's  pitch  and  lying  over  the 
ground,  the  drawing  is  made  on  the  pa- 
per and  shadowed  with  the  black-lead 
pencil.  The  action  of  the  pencil  thus  de- 
taches the  ground  which  adheres  to  the 
paper,  according  to  the  degree  to  which 
the  finishing  is  carried  ;  the  paper  being 
then  removed,  the  work  is  bit  in  the 
ordinary  way.  Stippling  is  also  executed 
on  the  etching  ground  %  dots  instead  of 
lines  made  with  the  etching  needle,  which 
according  to  the  intensity  of  the  shad- 
ow to  be  represented,  are  made  thicker 
and  closer.  The  work  is  then  bit  ir. 
Etching  on  Steel  is  executed  much  in  the 
same  way  as  in  the  process  on  copper. 
The  plate  is  bedded  on  common  glazier's 


eng] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


157 


putty,  and  a  ground  of  Brunswick  black 
is  laid  in  the  usual  way,  through  which 
the  needle  scratches.  It  is  then  bit  in, 
in  the  way  above  desctibed. 

Mezzotinto  Engraving.  In  this  species 
of  engraving  the  artist,  with  a  knife  or 
instrument  made  for  the  purpose,  roughs 
over  the  whole  surface  ot  the  copper  in 
every  direction,  so  as  to  make  it  suscep- 
tible of  delivering  a  uniform  black, 
smooth,  or  flat  tint.  After  this  process 
the  outline  is  traced  with  an  etching  nee- 
dle, and  the  lightest  parts  are  scraped 
out,  then  the  middle  tints  so  as  to  leave 
a  greater  portion  of  the  ground,  and  so 
on  according  to  the  depth  required  in  the 
several  parts  of  the  work. 

Aquatinta  Engraving,  whose  effect 
somewhat  resembles  that  of  an  Indian- 
ink  drawing.  The  mode  of  effecting  this 
is,  (the  design  being  already  etched)  to 
cover  the  plate  with  a  ground  made  of 
resin  and  Burgundy  pitch  or  mastic  dis- 
solved in  rectified  spirit  of  wine,  which 
is  poured  over  the  plate  lying  in  an  in- 
clined position.  The  spirit  of  wine,  from 
its  rapid  evaporation,  leaves  the  rest  of 
the  composition  with  a  granulated  text- 
ure over  the  whole  of  the  plate,  by  which 
means  a  grain  is  produced  by  the  aqua- 
fortis on  the  parts  left  open  by  the  evapo- 
ration of  the  spirit  of  wine.  The  margin 
of  the  plate  is  of  course  protected  in  the 
usual  way.  After  the  aquafortis  has  bitten 
the  lighter  parts  they  are  stopt  out,  and 
the  aquafortis  is  again  applied,  and  so  on 
as  often  as  any  parts  continue  to  require 
more  depth.  Formerly  the  grain  used  to 
be  produced  by  covering  the  copper  with 
a  powder  or  some  substance  which  took 
a  granulated  form,  instead  of  using  the 
compound  above  mentioned ;  but  this 
process  was  found  to  be  both  uncertain 
and  imperfect.  In  the  compound  the 
grain  is  rendered  finer  or  coarser,  in  pro- 
portion to  the  quantity  of  resin  intro- 
duced. This  mode  of  engraving  was 
invented  by  a  Frenchman  of  the  name  of 
St.  Non,  about  1662.  He  communicated 
it  to  Jean  Baptiste  le  Prince,  who  died  in 
1781,  from  whom  it  was  acquired  by 
Paul  Sandby,  who  introduced  it  through 
the  medium  of  Mr.  Jukes  into  Eng- 
land. 

Etching  on  Glass.  The  glass  is  covered 
with  a  thin  ground  of  beeswax  :  and  the 
design  being  drawn  with  the  etching  nee- 
dle, it  is  subjected  to  the  action  of  sul- 
phuric acid  sprinkled  over  with  powder- 
ed flour  of  Derbyshire  spar.  After  four 
or  five  hours  this  is  removed,  and  the 
glass  cleaned  off  with  oil  of  turpentine, 


leaving  the  parts  covered  with  the  bees- 
wax untouched.  This  operation  may  be 
inverted  by  drawing  the  design  on  tho 
glass  with  a  solution  of  beeswax  and  tur- 
pentine, and  subjecting  the  ground  to  the 
action  of  the  acid. 

Engraving  on  Stone  or  Lithography. — 
A  modern  invention,  by  means  whereof 
impressions  may  be  taken  from  drawings 
made  on  stone.  The  merit  of  this  di»- 
covery  belongs  to  Aloys  Senefelder,  a 
musical  performer  of  the  theatre  at  Mu- 
nich about  the  year  1800.  The  following 
are  the  principles  on  which  the  art  of 
lithography  depends  :  First,  the  facility 
with  which  calcareous  stones  imbibe 
water ;  second,  the  great  disposition  they 
have  to  adhere  to  resinous  and  oily  sub- 
stances ;  third,  the  affinity  between  each 
other  of  oily  and  resinous  substances,  and 
the  power  they  possess  of  repelling  water 
or  a  body  moistened  with  water.  Hence, 
when  drawings  aro  made  on  a  polished 
surface  of  calcareous  stone  with  a  resinous 
or  oily  medium,  they  are  so  adhesive  that 
nothing  short  of  mechanical  means  can 
effect  their  separation  from  it,  and  whilst 
the  other  parts  of  the  stone  take  up  the 
water  poured  upon  them,  the  resinous  or 
oily  parts  repel  it.  Lastly,  when  over  a 
stone  prepared  in  this  manner  a  colored 
oily  or  resinous  substance  is  passed,  it 
will  adhere  to  the  drawings  made  as 
above,  and  not  to  the  watery  parts  of  the 
stone.  It  was  formerly  thought  that 
England  did  not  possess  a  sort  of 
stone  like  that  of  Germany,  suitable  to 
the  purposes  of  lithography  ;  this,  how- 
ever, is  now  known  to  be  erroneous,  as 
the  neighborhood  of  Bath  abounds  with 
it,  being  the  white  lias,  which  lies  imme- 
diately under  the  blue.  It  is  also  found 
in  Scotland.  The  ink  and  chalk  used  in 
lithography  are  of  a  saponaceous  quality  : 
the  former  is  prepared  in  Germany  from 
a  compound  of  tallow  soap,  pure  white 
wax,  a  small  quantity  of  tallow,  and  a 
portion  of  lamp-black,  all  boiled  together, 
and  when  cool  dissolved  in  distilled  wa- 
ter. The  chalk  for  the  crayons  used  in 
drawing  on  the  stone,  is  a  composition 
consisting  of  the  ingredients  above  men- 
tioned, but  to  it  is  added  when  boiling,  a 
small  quantity  of  potash.  After  the 
drawing  on  the  stone  has  been  executed 
and  is  perfectly  dry,  a  very  weak  solution 
of  vitriolic  acid  is  poured  upon  the  stone, 
which  not  only  takes  up  the  alkali  from 
the  chalk  or  ink,  as  the  case  may  be, 
leaving  an  insoluble  substance  behind  it, 
but  it  lowers  in  a  very  small  degree  that 
part  of  the  surface  of  the  stone  not  drawn 


158 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[• 


upon,  and  prepares  it  for  absorbing  wa-  i 
ter  with  greater  freedom.  Weak  gum 
water  is  then  applied  to  the  stone,  to 
close  its  pores  and  keep  it  moist.  The 
stone  is  now  washed  with  water,  and  the 
daubing  ink  applied  with  balls  as  in 
printing  ;  after  which  it  is  passed  in  the 
usual  way  through  the  press,  the  process 
of  watering  and  daubing  being  applied 
for  every  impression. 

There"  is  a  mode  of  transferring  draw- 
ings made  with  the  chemical  ink  on  pa- 
per prepared  with  a  solution  of  size  or 
gum  tragacanth,  which  being  laid  on  the 
stone  ana  passed  through  the  press  leaves 
the  drawing  on  the  stone,  and  the  pro- 
cess above  described  for  preparing  the 
stone  and  taking  the  impression  is  carried 
into  effect. 

In  Germany  many  engravings  are  made 
on  stone  with  the  burin,  in  the  same  way 
as  on  copper ;  but  the  very  great  inferi- 
ority of  these  to  copper  engravings  makes 
it  improbale  that  this  method  will  ever 
come  into  general  use. 

Perhaps  one  of  the  greatest  advantages 
of  the  art  of  lithography  is  the  extraordi- 
nary number  of  copies  that  may  be  taken 
from  a  block.  As  many  as  70,000  copies 
01  prints  have  been  taken  from  one  block, 
and  the  last  of  them  nearly  as  good  as  the 
first.  Expedition  is  also  gained,  inas- 
much as  a  fifth  more  copies  can  be  taken 
in  the  same  time  than  from  a  copper- 
plate :  and  as  regards  economy  the  ad- 
vantages over  every  other  species  of  en- 
graving is  very  great. 

Zincography.  This  art,  which  is  of  very 
recent  introduction  in  this  country  (so 
much  so,  indeed,  that  but  few  specimens 
are  as  yet  to  be  seen),  is  similar  in  princi- 
ple to  lithography,  the  surface  of  the 
plates  of  zinc  on  which  it  is  executed 
being  bit  away,  leaving  the  design  promi- 
nent or  in  relief.  We  have  seen  some 
beautiful  examples  of  this  art,  but  vary- 
ing little  in  their  appearance  from  those 
of  stone  engraving. 

Mr.  J.  II.  Friny,  of  England,  has  pro- 
posed a  mode  of  engraving  on  steel  and 
other  metals  by  means  of  electricity.  He 
employs  six  of  Smee's  batteries,  in  each 
the  size  of  the  platinized  silver  plate  was 
about  three  square  inches.  The  steel 
plate  to  be  engraved  was  connected  to  the 
zinc  end  of  the  batteries  ;  a  long  covered 
wire  is  placed  between  the  steel  plate  and 
the  zinc.  The  wire  in  communication  with 
the  platinized  silver,  was  used  as  an  etch- 
ing point  on  the  steel  plate.  The  wire,  i 
which  served  as  a  graver,  was  made  of  J 
platina;  when  held  a  glass  tube  protected  | 


it  from  the  hand.  In  proportion  to  the 
intensity  of  the  current  is  the  depth  of 
the  engraving. 

ERIOMETER.  An  optical  instrument 
proposed  by  the  late  Dr.  Young  for 
measuring  the  diameters  of  minute  par- 
ticles and  fibres,  by  ascertaining  the  di- 
ameter of  any  one  of  the  series  of  colored 
rings  they  produce.  "  The  eriometer  is 
formed  of  a  piece  of  card  or  a  plate  of 
brass,  having  an  aperture  of  about  a 
fiftieth  of  an  inch  in  diameter  in  the 
centre  of  a  circle  about  half  an  inch  in 
diameter,  and  perforated  with  about  eight 
small  holes.  The  fibres  or  particles  to  be 
measured  are  fixed  in  a  slider ;  and  the 
eriometer  being  placed  before  a  strong 
light,  and  the  eye  assisted  by  a  lens  ap- 
plied behind  the  small  hole,  the  rings 
of  colors  will  be  seen.  The  slider  must 
then  be  drawn  out  or  pushed  1  11  the 
limit  of  the  first  red  and  green  rug  (the 
one  selected  by  Dr.  Young)  coincides 
with  the  circle  of  perforations,  and  the 
index  will  then  show  on  the  scale  the 
size  of  the  particles  cr  fibres. 

ERVA  LENTA.  The  farina  or  meal  of 
the  common  lentil,  the  Ervum  Lens. 

ERMINE.  The  winter  hair  of  the  com- 
mon weasel  an  animal  indigenous  through 
the  whole  states.  The  fur  is  white,  long, 
thin,  and  silky.  The  animals  are  very 
abundant  about  Hudson's  Bay.  The  fur 
is  in  great  request,  and  was  formerly  one 
of  the  insignia  of  magistrates.  When 
used  to  line  cloaks,  the  black  tuft  of  the 
tail  is  sewed  to  the  skin  at  irregular  inter- 
vals. 

ESSENTIAL  OILS  or  VOLATILE 
OILS.  Under  this  term  are  included  all 
those  peculiar  compounds  obtained  by 
distilling  vegetable  substances  with  wa- 
ter, and  which  pass  over  along  with  the 
steam,  and  are  afterwards  condensed  in 
the  liquid  or  solid  form.  They  appear 
to  constitute  the  odoraus  principles  of 
vegetables.  Their  specific  gravity  fluctu- 
ates on  either  side  that  of  water ;  they 
are  very  sparingly  soluble  in  water,  and 
these  solutions  constitute  the  medicated 
waters  :  rose,  peppermint,  and  other  wa- 
ters being  such  solutions  of  the  respect- 
ive essential  oils.  They  dissolve  in 
alcohol  and  form  essences,  many  of  which 
are  used  as  perfumes.  When  these  oils 
are  pure,  they  evaporate  from  paper  when 
held  before  the  fire ;  but  if  adulterated 
with  fixed  oils,  they  leave  a  greasy 
stain,  and  seldom  dissolve  perfectly  in 
alcohol.  The  more  expensive  of  these 
oils  are  frequently  adulterated  with  the 
cheaper  ones,  and  this  fraud  can  only  be 


eth] 


CYCLOPEDIA    OF   THE    USEUL    ARTS. 


159 


detected  by  an  experienced  nose.  Their 
chief  use  is  in  perfumery,  on  account 
of  their  odour,  and  in  medicine  they  form 
valuable  stimulants.  They  are  inflam- 
mable, and  are,  with  a  few  exceptions, 
compounds  of  hydrogen,  oxygen,  and 
carbon.  The  essence  of  turpentine,  of 
lemons,  and  a  few  others,  are  hijdro- 
carbons. 

ETHER.  In  Chemistry,  this  term  is 
applied  to  a  highly  volatile,  fragrant,  in- 
flammable, and  intoxicating  liquid,  pro- 
duced by  distilling  a  mixture  of  equal 
weights  of  sulphuric  acid  and  alcohol. 
When  these  liquids  mutually  act  on  each 
other,  a  series  of  complicated  changes 
ensue,  which  terminate  in  the  conversion 
of  alcohol  into  ether.  Ether,  like  alco- 
hol, may  be  regarded  as  a  compound  of 
hydrocarbon  and  water;  and  if  alcohol 
be  considered  as  consisting  of  one  equiva- 
lent of  oletiant  hydrocarbon=14,  and 
one  of  water=9,  either  may  be  regarded 
as  constituted  of  tawolefiant  hydrocarbon 
(14X2)=28,  and  one  of  water=9  :  hence, 
the  equivalent  of  alcohol  being  14-f9=23, 
that  of  ether  will  be  14X2=28+9=37; 
and  the  process  of  etherification  may  bo 
stated  to  consist  in  the  abstraction  trom 
alcohol  of  one  half  of  its  elemental  water. 
By  some,  ether  is  regarded  as  the  oxide 
of  a  peculiar  hydrocarbon,  which  they 
term  ethule,  composed  of  4  equivalents  of 
carbon  and  5  equivalents  ot  hydrogen ; 
and  alcohol  must  in  that  case  be  consid- 
ered as  hydrate  of  ether. 

Ether,  or,  as  it  is  often  called,  to  dis- 
tinguish it  from  analogous  products  ob- 
tained by  the  intervention  of  other  acids, 
sulphuric  ether,  is  a  limpid  colorless  fluid, 
of  an  agreeable  odour,  and  a  hot  pungent 
taste.  Its  specific  gravity  is  about  0-713, 
though  that  of  the  shops  is  usually 
heavier ;  it  boils  at  about  98°,  and  freezes 
at  the  low  temperature  of  46°  below  0°. 
The  specific  gravity  of  ethereal  vapor 
compared  with  atmospheric  air  is  as  258 
to  100.  Ether  is  sparingly  soluble  in  wa- 
ter, which  takes  up  about  a  tenth  of  its 
bulk;  it  dissolves  in  all  proportions  in 
alcohol.  The  principal  use  ot  ether  is  in 
medicine.  When  taken  internally,  it  is 
stimulant;  and  it  is  sometimes  applied 
externally,  by  reason  of  the  cold  produced 
during  its  evaporation,  as  an  ingredient 
in  refrigerating  lotions. 

The  most  profitable  way  of  manufac- 
turing ether  has  been  pointed  out  by 
Boullay.  It  consists  in  letting  the  alco- 
hol drop  in  a  slender  stream  into  the  acid, 
previously  heated  to  the  etherifying  tem- 
perature.   If  the  acid  in  this  case  were 


concentrated  to  1*846,  the  reaction  would 
be  too  violent,  and  the  ether  would  be 
transformed  into  bicarbureted  hydrogen 
(dihydrate  of  carbon).  It  is  therefore 
necessary  to  dilute  the  acid  down  to  the 
density  of  1-780;  but  this  dilution  may 
be  preferably  effected  with  alcohol,  in- 
stead of  water,  by  mixing  three  parts  of 
the  strongest  acid  with  two  of  alcohol, 
specific  gravity  0-830,  and  distilling  off  a 
portion  of  the  ether  thereby  generated  ; 
after  which  the  stream  of  alcohol  is  to  be 
introduced  into  the  tubulure  of  the  re- 
tort through  a  small  glass  tube  plunged 
into  the  mixture  ;  this  tube  being  the 
prolongation  of  a  metallic  syphon,  whose 
shorter  leg  dips  into  a  bottle  filled  with 
alcohol.  The  longer  leg  is  furnished 
with  a  stop-cock,  for  regulating  at  plea- 
sure the  alcoholic  streamlet.  The  dis- 
tilled vapors  should  be  transmitted 
through  a  worm  of  pure  tin,  surrounded 
by  cold  water,  and  the  condensed  fluid 
received  in  a  glass  bottle.  The  quantity 
of  alcohol  which  can  be  thus  converted 
into  ether  by  a  given  weight  of  sulphuric 
acid,  has  not  hitherto  been  accurately  de- 
termined ;  but  it  is  at  least  double.  In 
operating  in  this  way,  neither  sulphurous 
acid  nor  sweet  oil  of  wine  is  generated, 
while  the  residuary  liquid  in  the  retort 
continues  limpid  and  of  a  merely  brown- 
ish yellow  color.  No  sulphovinic  acid  is 
formed,  and  according  to  the  experiments 
of  Geiger,  the  proportion  of  ether  ap- 
proaches to  what  theory  shows  to  be  the 
maximum  amount.  In  fact,  57  parts  of 
alcohol  of  0-S3  sp.  grav.  being  equivalent 
to  46-8  parts  of  anhydrous  alcohol,  yield, 
according  to  Geiger,  33£  parts  of  ether ; 
and  by  calculation  they  should  yield  37J. 

The  ether  of  the  first  distillation  is  ne- 
ver pure,  but  always  contains  a  certain 
quantity  of  alcohol.  The  density  of  that 
product  is  usually  0*78,  and  if  prepared 
by  the  first  of  the  above  methods,  con- 
tains, besides  alcohol,  pretty  frequently 
sulphurous  acid,  and  sweet  oil  of  wine ; 
impurities  from  which  it  must  be  freed. 
Being  agitated  with  its  bulk  of  milk  of 
lime,  both  the  acid  and  the  alcohol  are 
removed  at  the  same  time ;  and  if  it  be 
then  decanted  and  agitated,  first  with  its 
bulk  of  water,  next  decanted  into  a  re- 
tort containing  chloride  of  calcium  in 
coarse  powder,  and  distilled,  one  third 
of  perfectly  pure  ether  may  be  drawn 
over. 

ETHER,  ACETIC,  is  used  to  flavor  si- 
lent corn  spirits  in  making  imitation 
brandy.  It  may  be  prepared  by  mixing 
20  parts  of  acetate  of  lead,  10  parts  of  al- 


160 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[EVA 


cohol,  and  Hi  of  concentrated  sulphuric 
acid;  or  16  of  the  anhydrous  acetate,  5 
of  the  acid,  and  4£  of  absolute  alcohol; 
distilling  the  mixture  in  a  glass  retort 
into  a  very  cold  receiver,  agitating  along 
■with  weak  potash  ley  the  liquor  -which 
comes  over,  decanting  the  superaatant 
ether,  and  rectifying  it  by  re-distillation 
over  magnesia  and  ground  charcoal. 

Acetic  ether  is  a  colourless  liquid  of  a 
fragrant  smell  and  pungent  taste,  of  spec, 
grav.  0-866  at  45°  F.,  boiling  at  166°  F., 
burning  with  a  yellowish  flame,  and  disen- 
gaging fumes  of  acetic  acid.  It  is  soluble 
m  8  parts  of  water. 

ETCHING  VARNISHES.  The  var- 
nishes of  Mr.  Lawrence,  an  English  art- 
ist resident  in  Paris,  is  made  as  follows  : 
Take  of  virgin  wax  and  asphaltum,  each 
two  ounces,  of  black  pitch  and  burgundy 
pitch  each  half  an  ounce.  Melt  the  wax 
and  pitch  in  a  new  earthenware  glazed 
pot,  and  add  to  them,  by  decrees,  the  as- 
phaltum, finely  powdered.  Let  the  whole 
boil  till  such  time  as  that,  taking  a  drop 
upon  a  plate,  it  will  break  when  it  is 
cold,  on  bending  it  double  two  or  three 
times  betwixt  the  fingers.  The  varnish, 
being  then  enough  boiled,  must  be  taken 
off  the  fire,  and  after  it  cools  a  little,  must 
be  poured  into  warm  water  that  it  may 
work  the  more  easily  with  the  hands,  so 
as  to  be  formed  into  balls,  which  must 
be  kneaded,  and  put  into  a  piece  of  taf- 
fety  for  use. 

Care  must  be  taken,  first,  that  the  fire 
be  not  too  violent,  for  fear  of  burning  the 
ingredients,  a  slight  simmering  being  suf- 
ficient ;  secondly,  that  whilst  the  asphal- 
tum is  putting  in,  and  even  after  it  is 
mixed  with  the  ingredients,  they  should 
be  stirred  continually  with  the  spatula ; 
and  thirdly,  that  the  water  into  which 
this  composition  is  thrown  should  be 
nearly  of  the  same  degree  of  warmth 
with  it,  in  order  to  prevent  a  kind  of 
cracking  that  happens  when  the  water  is 
too  cold. 

The  varnish  ought  always  to  be  made 
harder  in  summer  than  in  winter,  and  it 
will  become  so  if  it  be  suffered  to  boil 
longer,  or  if  a  greater  proportion  of  the 
asphaltum  or  brown  resin  be  used.  The 
experiment  above  mentioned,  of  the  drop 
suffered  to  cool,  will  determine  the  de- 
gree of  hardness  or  softness  that  may  be 
suitable  to  the  season  when  it  is  usea. 

Preparation  of  the  hard  varnish  used 
by  Callot,  commonly  called  the  Florence 
Varnish : — Take  four  ounces  of  fat  oil 
very  clear,  and  made  of  good  linseed  oil, 
like  that  used  by  painters ;  heat  it  in  a 


clean  pot  of  glazed  earthenware,  and  af- 
terwards put  to  it  four  ounces  of  mastick 
well  powdered,  and  stir  the  mixture 
briskly  till  the  whole  be  well  melted, 
then  pass  the  mass  through  a  piece  of 
fine  linen  into  a  glass  bottle  with  a  long 
neck,  that  can  be  stopped  very  securely ; 
and  keep  it  for  the  use  that  will  be  ex- 
plained below. 

Method  of  applying  the  soft  varnish  to 
the  plate,  and  of  blackening  it : — The 
plate  being  well  polished  and  burnished, 
as  also  cleansed  from  all  greasiness  by 
chalk  or  Spanish  white,  fix  a  hand-vice 
on  the  edge  of  the  plate  where  no  work 
is  intended  to  be,  to  serve  as  a  handle 
for  managing  it  when  warm ;  then  put  it 
upon  a  chailng-dish,  in  which  there  is  a 
moderate  fire,  and  cover  the  whole  plate 
equally  with  a  thin  coat  of  varnish;  and 
whilst  the  plate  is  warm,  and  the  varnish 
upon  it  in  a  fluid  state,  beat  every  part  of 
the  varnish  gently  with  a  small  ball  or 
dauber  made  of  cotton  tied  up  in  taffety, 
which  operation  smooths  and  distributes 
the  varnish  equally  over  the  plate. 

EUDIOMETER.  This  term  is  gene- 
rally applied  to  instruments  for  facilitat- 
ing the  analysis  of  atmospheric  air,  or  ra- 
ther for  determining  the  quantity  of  ox- 
ygen contained  in  a  given  volume  of  air ; 
under  the  idea  that  the  salubrity  of  the 
air  depended  upon  its  relative  quantity 
of  oxygen.  We  now  know,  however, 
that  this  is  not  the  case,  and  that  the  re- 
lation of  the  oxygen  to  the  nitrogen  in 
the  atmosphere  is  not  subject  to  any  dis- 
cernible fluctuation. 

EVAPORATION.  The  conversion  of 
substances  into  vapour  is  one  of  the  most 
important  and  general  effects  of  heat. 
During  this  process,  a  considerable  quan- 
tity of  sensible  heat  passes  into  the  latent 
or  insensible  state.  When  a  vessel  of 
water  is  placed  upon  the  fire,  its  temper- 
ature gradually  rises  till  it  attains  212°  ; 
then,  although  it  remains  upon  the  fire, 
and  of  course  receives  heat  as  before,  it 
does  not  become  hotter,  but  is  gradually 
converted  into  steam  or  vapor ;  so  that 
the  effect  of  heat  is  not  to  elevate  tem- 
perature, but  to  change  state  or  form : 
that  is,  in  the  case  of  water,  to  convert  it 
into  steam.  Hence  we  assume  that 
steam,  though  not  hotter  than  water, 
contains  a  much  larger  quantity  of  heat, 
and  this  heat  again  makes  its  appearand 
when  the  steam  is  condensed  or  re-con- 
verted into  water.  At  whatever  temper- 
ature vapour  is  produced,  it  is  similarly 
constituted  ;  and  that  which  escapes  from 
water  at  ordinary  temperatures,  by  the 


'] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


161 


process  usually  called  spontaneous  evapo- 
ration, resembles  the  former  in  all  re- 
spects :  hence  it  is  that  evaporation  is  to 
surrounding  bodies  a  cooling  process ; 
and  that  in  the  converse  change,  or  the 
return  of  the  vapor  to  the  liquid  state, 
heat  is  evolved  and  rendered  sensible. 
The  same  general  phenomena  are  ob- 
served with  all  other  liquids,  and  those 
which  evaporate  rapidly  at  common  tem- 
peratures often  give  rise  to  the  produc- 
tion of  a  great  degree  of  cold ;  such  as 
spirit  of  wine,  or  ether.  If  the  latter  flu- 
id be  suffered  to  dribble  over  the  bulb  of 
a  thermometer,  it  will  cause  it  to  sink 
below  the  freezing  point  of  water ;  and 
by  accelerating  similar  cases  of  evapora- 
tion, we  obtain  most  intense  degrees  of 
artificial  cold. 

The  circumstances  that  principally  in- 
fluence the  process  of  evaporation  are, 
extent  of  surface,  and  the  state  of  the  air 
as  to  temperature,  dryness,  stillness,  and 
density. 

In  evaporating  by  surfaces  heated  with 
ordinary  steam,  it  must  be  borne  in  mind 
that  a  surface  of  10  square  feet  will  eva- 
porate fully  one  pound  of  water  per  min- 
ute, or  725X10=7250  gr.,  the  same  as 
over  a  naked  fire  ;  consequently  the  con- 
densing surface  must  be  equally  exten- 
sive. Suppose  that  the  vessel  is  to  re- 
ceive of  water  2500  lbs.,  which  corres- 
ponds to  a  boiler  5  feet  long,  4  broad, 
and  2  deep,  being  40  cubic  feet  by  mea- 
sure, and  let  there  be  laid  over  the  bot- 
tom of  this  vessel  8  connected  tubes  each 
5  inches  in  diameter  and  5  feet  long,  pos- 
sessing therefore  a  surface  of  5  feet  square. 
If  charged  with  steam,  they  will  cause 
the  evaporation  of  half  a  pound  of  wa- 
ter per  minute.  The  boiler  to  supply  the 
steam  for  this  purpose  must  expose  a  sur- 
face of  5  square  feet  to  the  fire.  It  has 
been  proved  expei-imentally  that  10  square 
feet  surface  of  thin  copper  can  condense 
3  lbs.  of  steam  per  minute,  with  a  differ- 
ence of  temperature  of  90  degrees  Fahr. 
In  the  above  example,  10  square  feet  eva- 
porate 1  lb.  of  water  per  minute ;  the 
temperature  of  the  evaporating  fluid  be- 
ing 212°  F.,  consequently  3  :  1  :  :  90:  O 
During  this  evaporation  the  difference 
of  the  temperature  is  therefore  =30°. 
Consequently  the  heat  of  the  steam 
placed  in  connection  with  the  inte- 
rior of  the  boiler,  to  produce  the  calcu- 
lated evaporation,  should  be,  212+30= 
242°,  corresponding  to  an  elastic  force  of 
53-6  inches  of  mercury.  "Were  the  tem- 
perature of  the  steam  only  224.  the  same 
boiler  in  the  same  time  would  produce  a 


diminished  quantity  of  steam,  in  the  pro- 
portion of  12  to  30 ;  or  to  produce  the 
same  quantity  the  boiler  or  tubular  sur- 
face should  be  enlarged  in  the  proportion 
of  30  to  12.  In  general,  however,  steam 
boilers  employed  for  this  mode  of  evapo- 
ration are  of  such  capacity  as  to  give  an 
unfailing  supply  of  steam. 

EXPANSION.  One  of  the  most  com- 
mon and  obvious  effects  of  heat,  which 
expands  or  enlarges  the  bulk  of  all  the 
forms  of  matter.  The  expansion  of  sol- 
ids by  increase  of  temperature  is  compar- 
atively small ;  but  it  may  be  rendered 
sensible  by  carefully  measuring  the  di- 
mensions of  any  substance  when  cold, 
and  again  when  heated  :  an  iron  bar,  for 
example,  fitted  to  a  gauge,  which  shows 
its  length  and  breadth",  will  no  longer 
pass  through  the  apertures  when  heated. 
Among  solids  the  metals  are  most  expans- 
ible and  contractile  by  heat  and  cold ; 
but  they  vary  much  in  this  respect,  as 
shown  in  the  following  table,  which  ex- 
hibits the  change  of  dimensions  which 
several  of  them  undergo  when  heated, 
from  the  freezing  to  the  boiling  point  of 
water : — 


Temperature. 


Platinum 
Steel    . 
Iron     . 
Copper 


120000 


Tin 

Lead 

Zinc 


212° 
120104 
120147 
120151 
120204 
120230 
120290 
120345 
120360 


The  average  expansion  of  glass  is  very 
nearly  the  same  as  that  of  platinum.  The 
expansibility  of  different  Liquids  is  also 
very  variable:  ether,  for  instance,  and 
alcohol,  are  more  expansible  than  wa- 
ter, and  water  more  than  mercury. 
The  expansibility  of  mercury  is  applied 
to  a  very  useful  purpose  in  the  construc- 
tion of  the  common  thermometer.  In 
general  all  liquids  expand  and  contract  in 
proportion  as  they  are  heated  and  cooled  ; 
but  to  this  law  there  is  a  remarkable  and 
anomalous  exception  with  regard  to  wa- 
ter. When  a  large  thermometer  tube  is 
filled  with  water  of  the  temperature  of 
60°,  and  placed  in  a  cold  situation,  or  in 
a  freezing  mixture  of  ice  and  salt,  the 
water  goes  on  shrinking  in  the  tube,  till 
it  has  attained  the  temperature  of  about 
40°  ;  and  then,  instead  of  continuing  to 
contract  till  it  freezes  (as  is  the  case  with 
equal  liquids),  it  slowly  expands,  and  ac- 
tually rises  in  the  tube"  until  it  conceals. 
In  this  case  the  expansion  above  40°  and 


162 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


b 


below  40°  seems  to  be  equal ;  so  that  the 
water  will  be  the  same  bulk  at  48°  and 
32°.  This  anomalous  expansion  of  water 
by  cold  is  productive  of  some  important 
consequences,  considered  as  a  natural 
operation ;  for  if  water,  like  other  fluids, 
went  on  increasing  in  density  till  it 
froze,  the  consequence  would  be  that 
large  bodies  of  water,  instead  of  being 
only  superficially  frozen  in  winter,  would 
be  converted  throughout  into  solid  mass- 
es of  ice.  Let  us  take  a  fresh  water  lake 
as  an  example.  The  earth  being  in  win- 
ter warmer  than  the  air,  the  heat  is  with- 
drawn from  the  surface  of  the  water  by 
the  cold  breezes  that  blow  over  it ;  and 
the  whole  body  of  water  has  its  tempera- 
ture lowered  to  40°,  which  is  the  point  of 
its  greatest  density,  and  a  temperature 
perfectly  congenial  to  fish  and  most  other 
aquatic  animals.  The  cold  now  continues 
to  operate  upon  the  surface  of  the  water  ; 
but,  instead  of  diminishing  its  bulk,  and 
therefore  rendering  it  heavier  than  the 
warmer  water  beneath,  it  expands  it,  and 
renders  it  lighter ;  so  that  under  these 
circumstances  a  stratum  of  ice-cold  wa- 
ter (at  32°)  will  be  found  lying  upon  the 
mass  of  warmer  water  beneath  it  (at  40°). 
The  influence  of  the  cold  continuing,  the 
surface  of  the  lake  will  soon  freeze,  but 
the  water  immediately  below  the  super- 
ficial covering  of  ice  will  be  found  com- 
paratively warm  ;  and  as  water  is  almost 
a  non-conductor  of  heat,  it  will  be  a  long 
time  before  the  ice  attains  any  thickness  ; 
and  the  whole  body  of  water,  if  of  any 
depth,  can  never  freeze  throughout.  In- 
deed, it  will  be  obvious  that  the  retarda- 
tion of  freezing  will  be  proportional  to  the 
depth  of  water  which  has  to  be  cooled, 
and  hence  some  very  deep  basins  or 
lakes  are  scarcely  ever  even  covered  by  ice. 

As  liquids  are  enlarged  and  consequent- 
ly rendered  specifically  lighter  by  heat, 
very  different  effects  are  produced  by  ap- 
plying heat  to  different  parts  of  the  ves- 
sels containing  them.  If  the  heat  be  ap- 
plied to  the  bottom  of  the  vessel,  it  as 
Boon  heated  equally  throughout,  and 
made  to  boil ;  but  if  "the  surface  only  be 
heated,  it  may  then  be  boiled  and  evapo- 
rated, while  the  lower  parts  remain  quite 
cold. 

Aeriform  bodies  and  vapors  are  the 
most  expansible  forms  of  matter,  and 
they  present  an  important  peculiarity: 
for  "in  other  substances  each  individual 
has  its  own  degree  of  expansion  and  con- 
traction, whereas  all  pure  aeriform  bodies 
expand  and  contract  alike ;  so  that  if  we 
accurately  determine  the  expansion  and 


contraction  of  any  one  of  them,  that 
knowledge  applies  to  all  the  rest.  100 
measures  of  air,  when  heated  from  the 
freezing  to  the  boiling  point  of  water, 
suffer  an  increase  of  bulk  equal  to  37*5 
parts  ;  so  that  100  cubic  feet  of  air  at  32° 
become  dilated  to  137i  cubic  feet  at  212°. 

EXPLOSION.  In  natural  philosophy, 
a  sudden  and  violent  expansion  or  the 
parts  of  any  object.  Explosion  differs 
from  expansion  in  this,  that  whereas  the 
former  is  always  sudden,  and  only  of  mo- 
mentary duration,  the  latter  is  the  effect 
of  some  gradual  and  continued  power, 
acting  uniformly  for  some  considerable 
time. 

EXTRACTS.  The  older  apothecaries 
used  this  term  to  designate  the  product 
of  the  evaporation  of  any  vegetable  juice, 
infusion,  or  decoction ;  whether  the  latter 
two  were  made  with  water,  alcohol,  or 
ether;  whence  arose  the  distinction  of 
aqueous,  alcoholic,  and  ethereous  extracts. 

Fourcroy  made  many  researches  upon 
these  preparations,  and  supposed  that 
they  had  all  a  common  basis,  which  he 
called  the  extractive  principle.  But  Chev- 
reul    and    other    chemists    have    since 

E roved  that  this  pretended  principle  is  a 
eterogeneous  and  very  variable  com- 
pound. By  the  term  extract,  therefore, 
is  now  meant  merely  the  whole  of  the 
soluble  matters  obtained  from  vegetables, 
reduced  by  careful  evaporation  to  either 
a  pasty  or  solid  consistence.  The  wa- 
tery extracts,  which  are  those  most  com- 
monly made,  are  as  various  as  the  vege- 
tables which  yield  them ;  some  contain- 
ing chiefly  sugar  or  gum  in  great  abund- 
ance, and  are  therefore  innocent  or  inert ; 
while  others  contain  very  energetic  im- 
pregnations. The  conduct  of  the  evapo- 
rating heat  is  the  capital  point  in  the  pre- 
paration of  extracts.  They  should  be  al- 
ways prepared,  if  possible,'  from  the  juice 
ot  the  fresh  plant,  by  subjecting  its  leaves 
or  other  succulent  part,  to  the  action  of 
a  powerful  screw  or  hydraulic  press: 
and  the  evaporation  should  be  effected 
by  the  warmth  of  a  water-bath,  heated 
not  beyond  100°  or  120°  F.  Steam  heat 
may  perhaps  be  applied  advantageously 
in  some  cases,  where  it  is  not  likely  to 
decompose  any  of  the  principles  of  the 
plant.  But  by  far  the  best  process  for 
making  extracts  is  in  vacuo.  It  is  much 
easier  to  fit  up  a  proper  apparatus  of  this 
kind,  than  most  practical  men  imagine. 
The  vacuum  may  either  be  made  through 
the  agency  of  steam,  as  there  pointed 
out,  or  by  means  of  an  air-pump.  One 
uowerful  air-pump  may  form  and  main- 


FAl] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


163 


tain  a  good  vacuum  under  several  re- 
ceivers, placed  upon  the  flat-ground 
flanges  01  so  many  basins,  each  provided 
with  a  stop-cock  at  its  side  for  exhaus- 
tion. The  airless  basin  containing  the 
juice  being  set  on  the  shelf  of  a  water- 
bath,  and  exposed  to  a  proper  tempera- 
ture, will  furnish,  in  a  short  time,  a  large 
quantity  of  medicinal  extract,  possessing 
the  properties  of  the  plant  unimpaired. 

For  exceedingly  delicate  purposes,  the 
concentration  may  be  performed  in  the 
cold,  by  placing  saucers  filled  with  the 
expressed  juice"  over  a  basin  containing 
sulphuric  acid,  putting  a  glass  receiver 
over  them,  and  exhausting  its  air. 

FAINTS.  An  impure  spirit,  which 
comes  over  at  the  commencement  and 
termination  of  distillation.  The  first  is 
called  strong,  and  the  last  weak  faints. 
Faints  are  impregnated  with  fetid  vola- 
tile oils,  which  are  unwholesome,  and  re- 
quire to  be  separated  by  rectification. 

FALLING,  or  weight  of  bodies  ;  an 
important  phenomenon,  which  used  to  be 
ascribed  to  gravitation,  a  translation  of 
the  word  weights ;  so  that,  according  to 
this  wordy  philosophy,  weight  was  ow- 
ing to  weight.  But  it  is  now  con- 
sidered as  well  proved,  that  all  central 
force  in  planets  is  a  necessary  result  of 
the  simultaneous  orbit,  or  progressions, 
and  the  rotary  motions,  and  that  the  di- 
rection to  the  centre  is  the  constant  dia- 
gonal of  those  motions,  and  the  increase 
in  the  diagonal  the  exact  quantity  fallen 
in  a  given  time.  The  rotation  is  a  de- 
flection from  the  line  of  the  orbit  motion, 
and  this  being  much  greater,  the  body 
deflected  by  the  rotation  is  carried  by 
the  greater  motion  obliquely  to  the  com- 
mon centre  of  both  motions.  This  is  ob- 
vious in  the  equatorial  plane,  but,  in  lat- 
itudes, the  diagonal  is  compounded  of 
the  orbit  motions  as  one  force,  and  of  the 
sine  and  co-sine  as  to  the  rotatory  or  de- 
flective force ;  and  the  square  of  the  sine 
and  co-sine  being  equal  to  the  square  of 
the  radius,  every  where  alike,  the  fall  in 
direction  and  quantity  agrees  with  that  at 
the  equator.  The  orbit  velocity  in  a  se- 
cond is  98,132  feet,  the  equatorial  circle 
is  1525  feet  nearly,  or  in  the  perpendicu- 
lar 970-85  feet,  that  101-1  to  1,  and  this 
inversely,  as  6.28318  the  circle  to  the  ra- 
dius 1,  the  resulting  force  in  the  radius 
is  16-08725  feet  as  the  mean  fall.  Or, 
taking  the  two  motions  as  9S132  to  1525, 
and  inversely  as  4,  the  square  of  the  di- 
ameter to  1,  we  also  get  16-08725.  The 
squaring  the  forces,  and  extracting  the 
root  of  their  sum,  gives  an  analagous  re- 


sult, but,  for  popular  explanation,  the 
preceding  may  suffice. 

FALLOW.     In  agriculture,  lands  are 
said  to  be  under  fallow  when  they  are 
without  a  regular  crop  of  corn  or  pulse. 
A  naked  fallow  is  one  in  which  the  soil 
remains  a  whole  year  without  any  crop 
whatever;   and  a  turnip  or  green  crop 
fallow  is  one  in  which  the  lands  after  be- 
ing without  a  crop  from  harvest  till  the 
beginning  of  summer,  and  being  proper- 
ly labored  during  that  period,  ure  sown 
with  turnips  or  other  similar  crops  in 
rows,  and  the  grounds  cultivated  in  the 
intervals.     Fallowing  was  practised  by 
the  Romans  on  all  soils  whatever,  and 
has  been   continued  through  the  dark 
ages,  in  all  the  cultivated  parts  of  Eu- 
rope, so  as  to  have  become,  till  lately,  a 
f general  habit  in  the  treatment  of  arable 
ands.    The  practice  of  taking  two  corn 
crops,  and  then  allowing  the  land  to  rest 
or  he  fallow,  was,  till  the  commencement 
of  the  present  century,  prevalent  through- 
out Europe,  and  it  is  still  a  very  common 
fa-actiee  in  most  parts  of  that  Continent. 
t  appears  to    have    been  first  broken 
through  by  the  Flemings  about  the  end 
of  the  16th  century ;   and  subsequently 
in  Britain,  with  the  culture  of  turnips, 
above  a  century  and  a  half  later.    Fal- 
lows, under  the  most  improved  systems 
of  agriculture,  are  no  longer  had  recourse 
to  in  the  case  of  free  and  easily  worked 
soils,  where  turnip  fallows  are  made,  or 
drill  crops  of  legumes  are  substituted; 
but  in  very  strong  clays  they  are  still 
found  necessary,  and  this  will  probably 
continue  to  be  the  case  till  by  the  "  fre- 
quent drain  system,"  and  long-continued 
culture,  the  strong  clays  become  friable 
and  fit  for  the  drill  husbandry,  like  the 
sandy  loams  and  other  free  soils.     A 
perfect  system  of  agriculture  will  com- 
pletely dispense  with  fallow ;  under  clover 
and  green  crops  the  ground  recovers  its 
mineral  ingredients,  and  acquires  an  ad- 
dition of  vegetable  matter;    it  is  thus 
richer  after  clover  or  green  cropping  than 
before,  or  than  it  would  be  by  naked  fal- 
low. 

FAN,  FANNERS,  or  FANNING  MA- 
CHINE. A  machine  for  separating  the 
chaff,  husks,  dust,  or  other  light  matters 
from  seeds  which  are  to  be  preserved  for 
sowing,  or  for  some  other  purpose  in  ge- 
neral or  domestic  economy.  The  air  is 
put  in  motion  by  a  wheel,  commonly  driv- 
en by  hand  with  leaves  or  fans  instead  of 
spokes,  directed  in  a  stream  against  the 
seeds  to  be  fanned;  which  seeds  are 
placed  in  a  hopper,  so  regulated  as  to 


164 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


fFAT 


proportion  their  descent  through  the 
stream  of  air  to  the  force  of  the  current 
created  by  the  fan  wheel.  Before  fan- 
ners were  invented  the  process  was  per- 
formed by  hand  in  a  manner  the  reverse 
of  what  it  is  now  by  machinery ;  that  is, 
the  seeds  and  refuse  to  be  separated  from 
them  were  taken  up  in  shovelfulls,  and 
thrown  to  as  great  a  distance  as  possible, 
through  the  calm  air ;  when  the  full-bo- 
died seeds,  being  the  heaviest,  were 
found  at  the  greatest  distance,  and  the 
chaff  and  other  matters  nearer,  according 
to  their  degree  of  lightness.  With  the 
progress  of  the  arts,  a  system  of  screens 
and  sieves  was  added  to  the  fanning  ma- 
chine, in  consequence  of  which,  as  it  se- 
parated the  seed  from  every  kind  of  re- 
fuse, it  is  called  a  winnowing  machine ; 
and  in  that  case,  it  not  only  separates  the 
chaff  and  other  light  matters  generally 
from  the  heavy  matters,  but  it  parts  both, 
according  to  their  bulk  and  weight;  so 
that  the  seed  comes  from  the  winnowing 
machine  fit  for  being  measured  up  for 
the  market  or  store-room,  and  the  vari- 
ous kinds  of  inferior  products  in  a  state 
fit  for  immediate  use. 

FARINA.  The  flour  of  any  variety  of 
corn  or  starchy  root,  as  the  potato,  arrow 
root,  &c.  It  is  only  a  species  ot  pure 
btarch. 

FATS  occur  in  a  great  number  of  the 
animal  tissues,  being  abundant  under  the 
skin  in  what  is  called  the  cellular  mem- 
brane, round  the  kidneys,  in  the  folds  of 
the  omentum,  at  the  base  of  the  heart, 
in  the  mediastinum,  the  mesenteric  web, 
as  well  as  upon  the  surface  of  the  intest- 
ines, and  among  many  of  the  muscles. 
They  vary  in  consistence,  color,  and 
smell,  according  to  the  animals  from 
which  they  are  obtained  ;  thus,  they  are 
generally  fluid  in  the  cetaceous  tribes, 
soft  and  rank-flavored  in  the  carnivorous, 
solid  and  nearly  scentless  in  the  rumi- 
nants, usually  white  and  copious  in  well- 
fed  young  animals  ;  yelloAvish  and  more 
scanty  in  the  old.  Their  consistence  va- 
ries also  according  to  the  organ  of  their 
production  ;  being  firmer  under  the  skin, 
and  in  the  neighborhood  of  the  kidneys, 
than  among  the  moveable  viscera.  Fat 
forms  about  one  twentieth  of  the  weight 
of  a  healthy  animal.  But  as  taken  out" by 
the  butcher  it  is  not  pure,  for  being  of  a 
vesicular  structure,  it  is  always  enclosed 
in  membranes,  mixed  with  blood,  blood- 
vessels, lymphatics,  &c.  These  foreign 
matters  must  first  be  separated  in  some 
measure  mechanically,  after  the  fat  is 
minced  small,  and  then  more  completely 


by  melting  it  along  with  hot  water,  pass- 
ing it  through  a  sieve,  and  letting  tho 
whole  cool  very  slowly.  By  this  means 
a  cake  of  cleansed  fat  wiirbe  obtained. 
Many  plans  of  purifying  fats  have  been 
proposed ;  one  of  the  best  is  to  mix  two 
per  cent  of  strong  sulphuric  acid  with  a 
quantity  of  water,  in  which  the  tallow  is 
heated  for  some  time  with  much  stirring ; 
to  allow  the  materials  to  cool,  to  take  off 
the  supernatant  fat,  and  re-melt  it  with 
abundance  of  hot  water.  More  tallow 
will  thus  be  obtained,  and  that  consider- 
ably whiter  and  harder  than  is  usually 
procured  by  the  melters. 

Fat  is  deposited  in  cells  in  the  cellular 
tissues  of  the  animal ;  when  viewed  un- 
der the  microscope  they  are  partly  poly- 
gonal, partly  reniform  particles,  which 
are  connected  together  by  very  thin  mem- 
branes. These  may  be  ruptured  by  me- 
chanical means,  then  separated  by  tritu- 
rating the  fresh  fats  with  cold  water,  and 
passing  the  unctuous  matter  through  a 
sieve.  The  particles  float  in  the  water, 
but  eventually  collect  in  a  white  granular 
crystalline  appearance,  like  starch.  Each 
of  them  consists  of  a  vesicular  integu- 
ment, of  the  nature  of  stearine,  and  an 
interior  fluid  like  elaine,  which  afterwards 
exudes.  The  granules  float  in  the  water, 
but  subside  in  spirits  of  wine.  When 
digested  in  strong  alcohol,   the  liquid 

?art  dissolves,  but  the  solid  remains, 
hese  particles  differ  in  shape  and  size, 
as  obtained  from  different  animals  ;  those 
of  the  calf,  ox,  sheep,  are  polygonal,  from 
i  to  -j.l_.  of  an  inch  in  diameter ;  those 
of  the  sow  are  kidney-shaped,  and  from 
^  to  -i ;  those  of  a  man  are  polygon- 
al, and  from  '  to  -g~;  those  of  in- 
sects are  spherical,  and  at  most  _*  of 
an  inch. 

Fats  all  melt  at  a  temperature  much 
under  212°  F.  When  strongly  heated 
with  contact  of  air,  they  diffuse   white 

Eungent  fumes,  then  blacken,  and  take 
re.  When  subjected  to  distillation, 
they  afford  a  changed  fluid  oil,  carbureted 
hydrogen,  and  the  other  products  of  oily 
bodies.  Exposed  for  a  certain  time  to 
the  atmosphere,  they  become  rancid,  and 
generate  tne  same  fat  acids  as  they  do  by 
saponification.  In  their  fresh  state  they 
are  all  composed  principally  of  stearine, 
margarine,  and  oleine,  with* a  little  color- 
ing and  odorous  matter. 
Fats  are  true  chemical  salts,  being  com- 

?osed  of  a  fatty  acid  united  to  a  base, 
his  base    is  generally  glycerine.    The 
acids  are  either  stearic  acid,  which  is 


fea] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


165 


found  abundantly  in  the  hard  fats,  as 
suet  and  tallow, 

Margaric  acid,  also  a  solid,  found  in 
the  crystalline  portion  which  cold  throws 
out  of  olive  oil ;  it  is  also  found  in  ani- 
mal fats  and  oleic  acid,  which  is  found 
abundantly  in  olive  oil,  and  all  liquid  fats 
and  oils. 

The  properties  of  stearine  and  claine, 
or  of  stearic  and  oleic  acids  vary  at  dif- 
ferent seasons  and  under  various  circum- 
stances ;  thus,  butter,  in  summer,  con- 
sists of  60  of  oleine  and  40  of  stearine  ; 
in  winter,  of  37  of  oleine,  and  63  of  stear- 
ine ;  the  former  substance  being  yellow, 
and  the  latter  white.  It  differs,  however, 
as  produced  from  the  milk  of  different 
cows,  and  also  accordiug  to  their  pas- 
ture. 

Animals  oils  and  fats  differ  only  in 
fluidity,  and  may  be  treated  of  together. 
Of  animal  oils,  whale  oils,  and  sperm  oils 
are  the  most  generally  known  in  this  coun- 
try :  the  fats  are  spermaceti,  butter,  tallow, 
lard,  and  suet.  Whale  or  train  oil  is  ex- 
tracted from  the  blubber  of  the  whale, 
principally  the  oalena  mystieetes  ;  origi- 
nally it  is  a  firm  solid  fat.  To  obtain  the 
oil,  the  blubber  is  melted  in  large  copper 
vessels,  a  large  quantity  of  water  sepa- 
rates, and  on  the  surface  there  floats  a 
solid  matter  called  fenks,  which  is  proba- 
bly coagulated  albumen ;  the  more  mode- 
rate the  heat,  and  the  shorter  its  dura- 
tion, the  paler  and  better  the  oil.  The 
deep  color  is  owing  to  too  much  boiling, 
and  perhaps  to  blood  and  impurities  mix- 
ed with  it.  The  Greenland  oil  is  pale 
and  free  from  smell,  and  burns  with  a 

Sure  and  bright  flame.  By  adding  cold 
rawn  oil  it  is  made  more  fluid  and  com- 
bustible. Chloride  of  lime  deprives  it  of 
its  offensive  odor.  It  boils  at  600°,  and 
may  be  distilled,  but  it  then  is  an  altered 
oil.  Sperm  oil  forms  part  of  the  oily  sub- 
stance in  the  cranium  of  the  spermaceti 
whale  (physeter  macrocephalus).  The 
oil  is  separated  by  putting  the  mass  in 
a  woollen  bag  and  pressing  it,  when  the 
oil  runs  out.  This  kind  of  oil  is  purer 
than  train,  and  burns  away  without 
leaving  charcoal  on  the  wicks.  The 
manner  of  obtaining  the  solid  fats  has 
been  given ;  when  soft  it  is  called  lard, 
when  hard  taUow.  It  is  insoluble  in 
water  and  alcohol,  melts  at  90°  or  100°  ; 
by  raising  the  heat  it  becomes  acrid,  and 
gives  off  a  pungent  vapor.  In  close  ves- 
sels it  is  decomposed,  and  among  other 
substances  yields  a  large  quantity  of  ole- 
fiant  gas.  It  is  inflammable,  and  affords 
by  combustion  water  and  carbonic  acid. 


FEATHERS,  the  peculiar  covering  of 
birds,  consist  of  the  tube,  the  shaft,  and 
the  barbs.  The  tube  is  a  hollow,  trans- 
parent, horny  cylinder,  constituting  the 
root  of  the  feather ;  the  shaft  is  elastic, 
and  contains  a  white,  dry,  and  very  light 
pith.  The  tube  contains  a  vascular  sub- 
stance, composed  of  numerous  cells,  join- 
ed together,  and  communicating  with 
each  other.  This  is  enveloped  by  the 
tube,  but  communicates  with  the  skin  by 
a  small  opening  at  the  root  of  the  tube, 
and  is  probably  the  organ  by  which  the 
feather  is  nourished.  Two  sides  of  the 
shaft  are  covered  with  the  barbs,  running 
in  a  uniform  direction ;  and  each  barb 
forms,  of  itself,  a  little  shaft,  which  is 
covered,  in  a  similar  manner,  with  little 
barbs  on  each  edge.  On  the  wing-fea- 
thers, the  barbs  are  broader  on  one  side 
than  on  the  other  ;  but  on  the  other  fea- 
thers, they  are  equal  on  both  sides.  The 
barbs  are  provided  with  barbules,  by 
which  they  are  bound  so  firmly  to  each 
other,  as  to  appear  to  adhere  together, 
although  they  are,  in  fact,  entirely  sepa- 
rate. The  feathers  of  birds  are  periodi- 
cally changed.    This  is  called  moulting. 

T?he  best  method  of  curing  feathers  is 
to  lay  them  in  a  room  exposed  to  the  sun, 
and,  when  dried,  to  put  them  in  bags, 
and  beat  them  well  with  poles.  Fea- 
thers, when  chemically  analyzed,  seem  to 
Eossess  nearly  the  same  properties  as 
air. 

FEATHERS.  (Purification  of.)— 
The  following  is  an  outline  of  Heal's  pro- 
cess : — 

"  The  feathers  are  first  placed  in  what 
is  termed  a  steam-cistern,  a  chamber  of 
iron,  having  its  floor  formed  of  perforat- 
ed metal,  through  which  a  current  of 
steam  is  made  to  enter  with  considerable 
force,  to  fill  every  portion  of  the  cistern, 
and  thoroughly  saturate  the  mass  which 
it  contains.  This  continues  for  some 
time,  the  effect  upon  the  feathers  being 
analogous  to  that  produced  upon  metallic 
substances  when  exposed  to  the  red  heat 
of  a  furnace.  Every  particle  of  animal 
matter  they  contain  is  fused  and  driven 
off,  being  carried  away  by  the  steam  as 
it  rushes  through  the  mass  and  escapes 
by  an  aperture  for  the  purpose  in  the 
roof  of  the  cistern.  The  feathers,  now  of 
course  in  a  damp  state,  are  next  placed  in 
a  large  hollow  cylinder  of  iron,  into  which 
by  means  of  a  blowing  machine,  is  carried 
a  rapid  current  of  air,  heated  by  a  fur- 
nace to  a  temperature  of  300°.  This,  like 
the  first  cylinder,  contains  a  revolving  in- 
strument of  iron,  but  having  arms  or  bars 


166 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[> 


of  iron  ;  and  these,  driven  at  a  great  velo- 
city, pass  through  and  through  the  mass, 
thoroughly  separate  it,  and  keep  the  fea- 
thers constantly  in  motion  :  thus  allow- 
ing the  current  of  hot  and  drying  air  to 
permeate  them  freely,  and  effectually 
separating  every  fibre  of  them,  while 
through  a  floor  of  wire- work  passes  away 
a  large  quantity  of  dust  and  refuse,  which 
must  be  disengaged.  Lastly,  the  feathers 
are  placed  in  a  hollow  cylinder  of  perfor- 
ated metal,  in  which  revolves  a  'fan,' 
composed  of  four  plates  of  metal,  fixed  at 
equal  distances  from  each  other,  into  a 
horizontal  bar.  This  is  driven  with  im- 
mense velocity,  making  about  900  revo- 
lutions in  a  minute,  and  carrying  round 
the  feathers  with  it;  the  dust,  not  al- 
ready removed  in  the  drying  cylinder,  is 
separated  by  the  powerful  current  of  air 
which  is  driven  through  them,  and,  pass- 
ing the  perforations  of  the  cylinder,  is 
carried  away  by  a  drain  beneath.  By  this 
means  the  feathers  are  rendered  perfectly 
sweet,  pure,  and  dry." 

FELSPAR.  An  important  mineral 
composed  of  silica,  alumina,  and  potash, 
with  traces  of  lime,  and  often  of  oxide  of 
iron.  Common  felspar  is  of  various 
shades  of  white  and  red ;  it  forms  an  in- 
gredient in  granite,  and  is  the  base  of 
some  other  rocks.  It  is  often  crystalized, 
and  cleaves  into  rhomboidal  fragments. 

FELTING.  The  process  by  which 
different  kinds  of  fur  or  wool  are  blended 
into  a  compact  texture  for  the  manufac- 
ture of  hats.  The  anatomical  peculiari- 
ties of  the  different  hairs  or  furs  are 
much  concerned  in  the  perfection  of  the 
felt ;  they  must  be  such  as  to  enable  them 
to  interlace  and  intertwine  with  each 
other.  Hare  and  rabbit  fur,  wool,  and 
beaver  are  the  chief  materials  used  ;  they 
are  mixed  in  proper  proportions,  and  arc 
tossed  about  by  the  strokes  of  a  vibrating 
string  or  bow  till  they  become  duly  mat- 
ted together.  The  rapid  alternations  of 
its  motion  being  peculiarly  well  adapted 
to  remove  all  irregular  knots  and  adhe- 
sions among  the  fibres,  and  to  dispose 
them  in  a  very  light  and  uniform  arrange- 
ment. This  texture,  when  pressed  under 
cloths  and  leather,  readily  unites  into  a 
mass  of  some  firmness.  This  muss  is 
dipped  into  liquor  containing  a  little  sul- 
phuric acid  ;  and,  when  intended  to  form 
a  hat,  it  is  first  moulded  into  a  large  con- 
ical figure,  and  this  is  afterwards  reduced 
in  its  dimensions  by  working  it  for  seve- 
ral houre  with  the  hands."  It  is  then 
formed  into  a  flat  surface,  with  several  con- 
centric folds,  which  are  still  further  com- 


pacted, in  order  to  make  the  brim,  and 
the  circular  part  of  the  crown,  and  forced 
on  a  block  which  serves  as  a  mould  for 
the  cylindrical  part.  The  nap,  or  outer  por- 
tion of  the  fur,  is  raised  with  a  fine  win 
brush,  and  the  hat  is  subsequently  dyed, 
and  stiffened  on  the  inside  with  glue. 

FENCE.  Any  continuous  line  of  ob- 
stacle interposed  by  art  between  one  por- 
tion of  the  surface  of  land  and  another, 
for  the  purpose  of  separation  or  exclu- 
sion. The  land  of  obstacle  or  material 
differs  according  to  the  animals  which 
are  to  be  separated,  excluded,  or  confin- 
ed, and  the  nature  of  the  soil  and  situa- 
tion. All  fences  are  either  live  or  dead, 
or  a  compound  of  these.  Live  fences 
are  hedges  ;  that  is,  tows  of  shrubs  placed 
close  together,  and  pruned  on  the  sides, 
so  as  toform  a  sort  of  living  wall.  Dead 
fences  are  either  stone  walls,  mounds  of 
earth,  or  structures  of  wood  or  of  other 
materials  raised  above  the  ground's  sur- 
face, or  upon  ditches  excavated  in  it.  The 
latter  are  sometimes  filled  with  water. 
Mixed  fences  are  those  in  which  some 
kind  of  dead  fence  is  used  with  some 
kind  of  live  fence  ;  for  example,  a  ditch 
with  a  bank  of  earth  on  one  side,  or  a 
ditch  with  a  wall  or  a  hedge  on  one  side ; 
the  latter  the  commonest  of  all  fences. 
The  introduction  of  fences  into  agricul- 
ture was  about  as  great  an  improvement 
in  the  progress  of  that  art,  as  that  of  the 
principle  of  the  division  of  labor  into  the 
art  of  manufacture. 

FERMENTATION.  When  certain 
vegetable  substances  are  dissolved  in 
water,  and  subjected  to  a  due  tempera- 
ture (between  65°  and  85°),  they  undergo 
a  series  of  changes  which  terminate  in 
the  production  of  alcohol  or  spirit ;  these 
changes  constitute  the  phenomena  of 
vinous  fermentation.  Sugar  and  some 
ferment  are  essential  to  the  process ;  and 
during  the  formation  of  the  alcohol  the 
sugar"  disappears,  and  carbonic  acid  is 
more  or  less  abundantly  evolved.  The 
simplest  ease  of  fermentation  is  that  of 
must,  or  of  the  expressed  juice  of  the 
grape,  which,  when  exposed,  either  in 
close  or  open  vessels,  to  a  temperature  of 
about  70*,  soon  begins  to  give  off  car- 
bonic acid,  and  to  "become  turbid  and 
frothy  ;  after  a  time  a  scum  collects  upon 
the  surface,  and  a  sediment  is  deposited  ; 
the  liquor,  which  had  grown  warm,  gra- 
dually cools  and  clears,  loses  its  sweet 
taste,  and  is  converted  into  wine.  The 
chief  compoueut  parts  of  must  are  water, 
sugar,  mucilage,  gluten,  and  tartar. 
During  the  fermentation  carbonic  acid 


fer] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


167 


escapes,  the  sugar  disappears,  and  with 
it  the  greater  part  of  the  mucilage  :  the 
gluten  chiefly  forms  the  scum  and  a  por- 
tion of  the  sediment ;  and  the  tartar,  ori- 
ginally in  solution,  is  thrown  down  in 
the  form  of  a  colored  deposit.  It  appears, 
therefore,  that  the  new  products,  which 
are  alcohol  and  carbonic  acid,  are  princi- 
pally formed  at  the  expense  of  the  sugar  ; 
and  Gay  Lussac's  experiments  have 
shown  that  45  pounds  of  sugar  are  re- 
solved, in  the  process  of  fermentation, 
into  23  of  alcohol  and  22  of  carbonic  acid. 
Sugar  and  water  alone  will  not  ferment; 
the  ingredient  requisite  to  the  commence- 
ment of  the  change  is  the  gluten,  which 
absorbs  in  the  first  instance  a  little  oxy- 
gen from  the  air,  becomes  insoluble,  and 
induces  the  subsequent  changes.  The 
reason  why  grapes  never  ferment  till  the 
juice  is  expressed,  seems  to  depend  upon 
the  exclusion  of  air  by  the  husk  or  mem- 
branes ;  and  if  grapes  be  bruised  in  a 
perfectly  close  vessel,  carefully  excluding 
oxygen,  the  juice  undergoes  no  change  ; 
so  that  the  mere  breaking  down  of  the 
texture  of  the  fruit  is  insufficient.  But 
a  very  short  exposure  of  the  pulp  to  air 
is  sufficient  to  induce  that  change  in  the 
juice  which  leads  on  to  fermentation, 
and  which  is  afterwards  independent  of 
the  further  contract  of  air,  the  evolution 
of  carbonic  acid  being  exclusively  refera- 
ble to  the  decomposition  of  sugar.  In 
beer  the  alcohol  is  derived  from  the  sugar, 
original  and  produced,  of  the  malt.  When 
wine  is  exposed  to  air  and  a  due  temper- 
ature, a  second  fermentation  ensues, 
which  is  called  acetous  fermentation,  and 
Avhich  terminates  in  the  production  of 
vinegar.  During  this  process  oxygen  is 
absorbed,  and  more  or  less  carbonic  acid 
in  most  cases  evolved  ;  but  the  apparent 
cause  of  the  formation  of  vinegar  is  the 
abstract  of  hydrogen  from  the  alcohol,  so 
as  to  leave  the  remaining  elements  in  such 
proportions  as  to  constitute  acetic  acid. 
Thus  alcohol  is  theoretically  constituted 
of  charcoal,  water,  and  hydrogen ;  and 
acetic  acid  of  charcoal  and  water  only ; 
the  oxygen  of  the  air,  therefore,  con- 
verts the  hydrogen  of  the  alcohol  into 
water,  and  so  effects  the  change  into 
vinegar. 

Essential  to  fermentation  are  :  1.  Sugar, 
or  an  equivalent  convertible  into  it.  2. 
Water.  3.  Heat,  or  increase  of  atomic 
activity.    4.  Leaven,  or  yeast.     5.  Air. 

Without  a  saccharine  substance  the  fer- 
mentation is  acetic,  or  vinegar;  with 
it  the  fermentation  is  vinous,  or  spiritu- 
ous.   These  are  followed  by  decomposi- 


tion or  putrescence,  called  the  ultimate, 
or  putrefactive  fermentation. 

It  is  most  rapid  from  70°  to  100°.  No 
vinous  or  beer  fermentation  takes  place 
below  55° ;  and  above  100°  the  acetous 
precedes  the  vinous  while  the  alcohol 
evaporates  as  formed.  It  is  slower  as  the 
heat,  or  atomic  activity,  descends  towards 
55°,  and  quicker  as  it  advances  towards 
100°.  Again,  heat  should  rise  inversely 
vs  quantity ;  100  gallons  will  do  best  at 
94°  ;  450  gallons  at  72°,  and  2000  gallons 
at  63°.  Small  vessels  part  with  heat  more 
rapidly  than  great  ones  ;  and  the  time  is 
inversely  as  the  heat ;  100  gallons'  at  63° 
would  take  8  days  instead  of  2.  Again, 
fermentation  generates  from  2°  to  22°  of 
heat,  as  quantity  and  strength,  and  the 
sinking  of  this  internal  heat  to  that  of  the 
surrounding  atmosphere,  is  the  signal  for 
the  termination  of  the  fermentation.  No 
operation  should  be  attempted  where  the 
atmosphere  is  less  than  50°,  and,  when 
less,  doors  and  vents  should  be  closed, 
and  fires  lighted.  If  the  atmosphere  is 
80°  or  90°,  the  liquid  must  be  set  to  work 
at  70°  or  80°  and  smaller  vessels  used  in 
summer  than  in  winter.  By  regulating 
the  heats,  fermentation  may  be  conducted 
with  success  in  every  season. 

When  fermentation  is  arrested,  bottles 
or  casks  of  hot  water  must  be  immersed, 
or  water  added  to  raise  the  temperature, 

When  the  fermentation  is  too  rapid,  it 
can  be  checked  either  by  adding  a  strong 
solution  of  wort  or  syrup,  or  cooling  with 
jets  and  ventilation,  or  by  evaporation 
from  the  outside  of  the  fermenting 
vessel. 

Whatever  diminishes  the  strength  of 
the  wort,  or  must,  increases  the  fermen- 
tation ;  whatever  increases  the  strength 
diminishes  the  fermentation. 

Heat  also  increases  it,  and  cold  dimi- 
nishes it. 

No  fermentation  takes  places  in  a  va- 
cuum, or  in  carbonic  acid  gas,  and  air  is 
essential ;  but,  it  is  not  necessary  to  leave 
the  fermenting  liquor  uncovered,  since 
the  air  penetrates  and  has  saturated  all 
the  materials.  When  the  fermentation 
has  commenced,  air  favors  the  acetous 
more  than  the  vinous  fermentation. 
Much  mixture  with  air  converts  the  fer- 
ment to  vinegar ;  and  while  the  fermenta- 
tion lasts,  the  liquor  is  protected  by  a 
stratum  of  carbonic  acid  gas  lying  over 
it. 

FERN  BOOT.  The  root  of  the  Aspi- 
di/amfilix  mas,  or  male  fern.  About  two 
drachms  of  the  dried  root,  in  powder, 
followed  up  by  a  brisk  purge,  is  occasion- 


168 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[fil 


ally    given    as    a    vermifuge.       It   was 
Madame  Noutfer's  celebrated  specific. 

FEEROCYANIC  ACID.  A  compound 
of  3  atoms  of  cyanogen,  2  of  hydrogen, 
and  1  of  iron.  It  is  the  ferrochyazic  acid 
of  Mr.  Porrett,  the  term  chyazic  being 
composed  of  the  initials  of  carbon,  hy- 
drogen, and  azote,  which  are  the  ultimate 
elements  of  hydro-cyanogen. 

FIBRE.  One  of  the  two  bases  of  all 
vegetable  structures.  It  may  be  com- 
pared to  hair  in  inconceivable  fineness, 
its  diameter  often  not  exceeding  1-1200 
of  an  inch;  also  the  name  of  the  finer 
divisions  of  roots. 

FIBRIN.  A  term  applied  by  chemists 
to  the  muscular  fibre  when  cleansed  by 
washing  from  all  adhering  impurities ; 
or  to  the  coagulum  of  the  blood  when 
the  whole  of  the  coloring  matter  is  washed 
out  of  it.  It  is  white,  insipid,  and  inodor- 
ous ;  its  ultimate  elements  are,  according 
to  Gay  Lussac  and  Thenard — 

Carbon  ....  53-36 
Hydrogen  .  .  .  7*02 
Nitrogen  .  .  .  19-93 
Oxygen  ....  1969 

It  is  merely  a  form  of  albumen. 

FIBROLltE.  A  rare  mineral  of  a  pe- 
culiar fibrous  texture,  accompanying  co- 
rundum from  the  Carnatic  and  from  China. 

FILE.  This  instrument  is  formed  by 
cutting  teeth  upon  a  plate  or  tool  of  soft 
steel  by  the  repeated  blows  of  a  straight- 
edged  chisel.  These  teeth  either  form  a 
single  series  of  straight  lines,  or  they  are 
crossed  by  a  second  series  ;  the  former 
are  called  "single  cut,  the  latter  double  cut 
files.  Files  are  required  to  be  extremely 
hard ;  and  unless  they  are  carefully  and 
skilfully  hardened,  they  are  apt  to  warp. 
The  best  files  are  made  exclusively  of 
cast  steel,  and  are  cut  by  hand,  none  of 
the  file-cutting  machines  producing  un- 
exceptionable tools. 

FILLIGREE  WORK.  This  work  is  a 
kind  of  enrichment  on  gold  or  silver, 
wrought  delicately  in  the  manner  of  little 
threads  or  grains,  or  both  intermixed. 
In  this  kind'of  work,  fine  gold  and  silver 
wire  are  often  curled  in  a  serpentine  form 
and  braided  through  each  other,  or  form- 
ed into  festoons  and  various  ornaments, 
entwisting  the  threads  to  give  them  a 
very  beautiful  effect.  This  art  is  very 
ancient,  and  was  brought  into  Europe 
from  the  east.  It  was  formerly  much 
used  for  decorating  images  and  the  tombs 
of  saints.  The  Hindoos  and  Chinese 
make  some  beautiful  works  of  this  kind, 
with  tools  which  are  very  coarse  and 
olumsy.     The  Malay  jewellers  make  a 


great  deal  of  silver  filligree  work,  and  gold 
also.  They  either  melt  their  gold  in  an 
earthen  rice  pot  or  in  a  clay  crucible. 
They  blow  their  fires  with  their  mouth, 
through  bamboo  tubes,  and  they  draw 
their  wire  much  as  we  do  ourselves ;  after 
having  drawn  it  sufficiently  fine,  they 
flatten  it  on  the  anvil,  and  give  it  a  pecu- 
liar twist  by  rubbing  it  on  a  block  with  a 
flat  stick.  They  then  form  it  into  leaves 
and  flowers  by  handiwork,  until  they 
have  the  number  to  form  the  pattern 
they  wish  to  execute  on  the  plate.  They 
always  have  the  pattern  beside  them  of 
the  full  size  they  wish  to  form  on  thp  gold 
plate.  They  fix  their  work  with  a  gluti- 
nous substance  made  of  a  berry  ground 
on  a  stone.  They  keep  this  substance  on 
a  piece  of  cocoa  nut.  After  all  the  leaves 
of  the  filligree  is  laid  on  the  plate — stuck 
on  bit  by  bit — a  solder  is  prepared  of  gold 
filings  and  borax  moistened  with  water, 
which  they  strew  over  the  plate,  then  put 
it  in  the  fire  till  the  whole  becomes  united. 
In  making  open  work  the  foliage  is  stuck 
on  a  card  with  the  berry  paste,  then  the 
work  is  strewn  over  with  the  solder  and 
put  into  the  fire,  when  the  card  burns 
away  and  the  whole  remains  united.  If 
the  piece  is  very  large  it  is  soldered  seve- 
ral times.  When  the  filligree  is  finished, 
they  cleanse  it  by  boiling  it  in  common 
salt  water  and  alum,  and  they  give  it  a 
fine  purple  color  by  boiling  it  in  water 
with  sulphur.  Except  in  India,  China, 
and  some  parts  of  Turkey,  this  art  is 
much  neglected  at  present/ 

FILTRATION  is  a  process  purely  me- 
chanical, for  separating  a  liquid  from  the 
undissolved  particles  floating  in  it,  which 
liquid  may  be  either  the  useful  part,  as  in 
vegetable  infusions,  or  of  no  use,  as  the 
washings  of  mineral  precipitates.  The 
filtering  substance  may  consist  of  any 
porous  matter  in  a  solid,  foliated,  or  pul- 
verulent form  ;  as  porous  earthenware, 
unsized  paper,  cloth  of  many  kinds,  or 
sand.  The  white  blotting  paper  sold  by 
the  stationers,  answers  extremely  well 
for  filters  in  chemical  experiments,  pro- 
vided it  be  previously  washed  with  dilute 
muriatic  acid,  to  remove  some  lime  and 
iron  that  are  generally  present  in  it.  Fil- 
ter papers  are  first  cut  square,  and  then 
folded  twice  diagonally  into  the  shape  of 
a  cornet,  having  the  angular  parts  round- 
ed off.  Or  the  piece  of  paper  being  cut 
into  a  circle,  may  be  folded  fan-like  from 
the  centre,  with  the  folds  placed  exteri- 
orly, and  turned  out  sharp  by  the  pres- 
sure of  the  finger  and  the  thumb,  tokeep 
intervals  between  the  paper  and  the  fun- 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


169 


uel  into  which  it  is  fitted,  to  favor  the 
percolation.  The  diameter  of  the  funnel 
should  he  ahout  three  fourths  of  its 
height,  measured  from  the  neck  to  the 
edge.  If  it  be  more  divergent,  the  slope 
will  be  too  small  for  the  ready  efliux  of 
the  fluid.  A  filter  covered  with  the  sedi- 
ment is  most  conveniently  washed  by 
spouting  water  upon  it  with^  a  little 
syringe.  A  small  camel's-hair  paint 
brush  is  much  employed  for  collecting 
and  turning  over  the  contents  in  their 
soft  state.  Agitation  or  vibration  is  of 
singular  efficacy  in  quickening  percola- 
tion, as  it  displaces  the  particles  of  the 
moistened  powders,  and  opens  up  the 
pores  which  had  become  closed.  Instead 
of  a  funnel,  a  cylinder  vessel  may  be  em- 
ployed, having  its  perforated  bottom 
covered  with  a  disc  of  filtering  powder 
folded  up  at  the  edges,  and  made  tight 
there  by  a  wire  ring.  Linen  or  calico  is 
used  for  weak  alkaline  liquors  ;  and  flan- 
nels, twilled  woollen  cloth,  or  felt-stuff, 
for  weak  acid  ones.  These  filter  bags 
are  often  made  conical  like  a  fool's  cap, 
and  have  their  mouths  supported  by  a 
woollen  or  metallic  hoop.  Cotton  wool 
put  loose  into  the  neck  of  a  funnel  an- 
swers well  for  filtering  oils  upon  the  small 
scale.  In  the  large  way,  oil  is  filtered  in 
conical  woollen  bags,  or  in  a  cask  with 
many  conical  tubes  in  its  bottom,  filled 
with  tow  or  cotton  wool.  Stronger  acid 
and  alkaline  liquors  must  be  filtered 
through  a  layer  of  pounded  glass,  quartz, 
clean  sand,  or  bruised  charcoal.  The  al- 
carrhazas  are  a  porous  biscuit,  of  stone- 
ware made,  in  Spain,  which  are  conve- 
nient for  filtering  water,  as  also  the  po- 
rous filtering-stone  of  Teneriffe,  largely 
imported  into  England  at  one  time,  but 
now  superseded  in  a  great  measure  by 
the  artificial  filters  patented  under  many 
forms,  consisting  essentially  of  strata  of 
gravel,  sand,  and  charcoal  powder. 

FIREARMS.  (See  Gun,  230.)  A  new 
gun  has  been  invented  by  Mr.  M.  Cass,  of 
Utica,  N.  Y.  This  gun  "is  loaded  at  the 
breech  with  ball  cartridge,  having  cham- 
bers for  twenty-six  charges.  It  is  also 
capped  at  the  same  time  that  it  is  charg- 
d.  These  twenty-six  charges  can  be 
red  in  about  three  minutes  without 
using  any  particular  haste.  The  car- 
tridge is  introduced  in  the  barrel  of  the 
gun  through  the  breech-pin,  which  is 
constructed  something  in  the  manner  of 
a  common  faucet,  being  turned  one  quar- 
ter round  by  a  small  lever  underneath 
the  barrel,  and  thus  admitting  the  charge, 
which  is  thrust  forward  from  its  chamber 


I 


by  a  small  ramrod  operating  from  behind 
by  means  of  another  smalllever. 

A  new  breech-loading  musket  has  been 
invented  in  Prussia,  which  may  be  short- 
ly described  thus  : — 

"  The  musket  has  no  lock,  and  is  load- 
ed at  the  stock  end  of  the  barrel.  The 
barrel  is  slightly  rifled,  but  the  grooves 
are  perfectly  straight,  and  not  spiral,  as  in 
the  American  gun.  The  common  charge 
is  one-half  of  that  used  in  the  old  per- 
cussion gun,  and  is  said  to  carrj  the  ball 
to  its  mark  nine  hundred  yards.  None 
of  the  powder  is  wasted,  the  fire  being 
communicated  from  the  side  of  the  bar- 
rel, and  not  from  the  breech.  This  is 
effected  by  an  ingenious  contrivance. 
The  part  of  the  cartridge  next  the  ball  is 
filled  with  an  explosive  substance  similar 
to  that  in  a  percussion  cap.  This  is  made 
to  explode  by  the  contact  of  a  piece  of 
steel  about  the  length  of  an  eight-penny 
nail,  which  passes  from  the  outside  of 
the  barrel  through  the  cartridge.  The 
gun  is  called  the  "  nail  firer."  It  can  be 
discharged  by  a  common  soldier  eight 
times  in  a  minute,  and  need  not  be  taken 
from  the  shoulder  to  be  reloaded. 

FIRE  BLAST.  A  term  of  very  doubt- 
ful meaning,  like  the  word  blight.  In 
agriculture  it  is  sometimes  applied  to 
plants  which  are  suffering  from  the  mil- 
dew fungi,  or  from  minute  insects ;  but 
its  legitimate  use  would  appear  to  be  ap- 
plicable only  when  the  delicate  parts  of 
plants  are  too  suddenly  exposed  to  a 
brilliant  sun,  and  the  rapid  transpiration 
which  takes  place  in  consequence  dries 
up  and  shrivels  their  leaves. 

FIREDAMP.  The  carburetted  hydro- 
gen gas  of  coal  mines. 

FIRE  ENGINE.  This  most  useful 
machine  is  constructed  in  a  variety  of 
forms,  which  all,  however,  agree  in  one 
principle.  It  generally  consists  of  a  dou- 
ble forcing  pump  communicating  with 
the  same  air  vessel ;  and  instead  of  a 
force-pipe  a  flexible  leathern  hose  is  used, 
through  which  the  water  is  driven  by 
the  pressure  of  the  condensed  air  in  the 
air  vessel.  The  an- 
nexed diagram  repre- 
sents a  section  of  the 
apparatus.  The  pipe 
T  descends  into  a  re- 
ceiver or  vessel  con- 
taining a  supply  of 
water.  This  pipe 
communicates  with 
two  suction  valves  V, 
which  open  into  the 
pump  barrels  of  two 


1T0 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


forcing  pumps  A,  B,  in  which  solid  pis- 
tons r,  are  placed.  The  piston  rods  of 
these  are  connected  with  a  working  beam 
F,  elongated  so  that  a  number  of  persons 
may  work  at  both  ends  of  it  at  once. 
Force-pump  barrel  above  the  valves  V, 
and  pipes  t,  t,  proceed  from  the  sides  of  the 
they  communicate  with  an  air  vessel  M, 
by  means  of  forcing  valves  V,  which  also 
open  upwards.  The  pipe  descends  into 
the  air  vessel  near  the  bottom.  This 
pipe  is  connected  with  the  flexible  leath- 
ern hose  L,  the  length  of  which  is  adapt- 
ed to  the  purposes  to  which  the  machine 
is  to  be  appfied.  The  extremity  of  the 
hose  may  be  carried  in  any  direction, 
and  may  be  introduced  through  the  doors 
and  windows  of  buildings.  By  the  alter- 
nate action  of  the  pistons,  water  is  drawn 
through  the  suction  valve,  and  propelled 
through  the  forcing  valves,  until  the  air 
in  the  top  of  the  vessel  M  is  highly  com- 
pressed. The  pressure  acts  on  the  sur- 
face of  the  water  in  the  vessel,  and  forces 
it  through  the  leathern  hose  in  a  con- 
tinued stream,  so  as  to  spout  from  its 
extremity  with  a  force  depending  partly 
on  the  degree  of  condensation,  and  partly 
on  the  elevation  of  the  extremity  of  the 
hose  above  the  level  of  the  engine.  It 
is  to  be  considered  that  the  pressure  of 
the  condensed  air  has,  in  the  first  in- 
stance, to  support  a  column  of  water,  the 
height  of  which  is  equal  to  the  level  of 
the  end  of  the  tube  above  the  level  of 
the  water  in  the  air  vessel ;  and  until  the 
pressure  exceeds  what  is  necessary  for 
this  purpose,  no  water  can  spout  from 
the  end  of  the  hose  ;  and,  consequently, 
the  force  with  which  it  will  so  spout  will 
be  proportional  to  the  excess  of  the  pres- 
sure of  the  condensed  air  above  the 
weight  of  the  column  of  water,  whose 
height  is  equal  to  the  elevation  of  the 
end  of  the  hose  above  the  level  of  the 
water  in  the  air  vessel. 

A  steam  fire-engine  has  been  built  by 
Mr.  Braithwaite,  of  London,  for  the  King 
of  Prussia.  It  is  intended  to  be  exclu- 
sively employed  for  the  protection  of  the 
public  buildings  of  Berlin. 

The  combustion  is  promoted  by  means 
of  an  exhauster,  instead  of  a  bellows  ;  the 
flue  is  in  two  lengths,  and  the  greatest 
diameter  5  inches.  The  steam-cylinder 
is  12  inches  in  diameter,  with  a  14  inch 
stroke.  The  water  cylinders  are  lOi  inch, 
in  diameter,  with  also  a  14  inch  stroke. 
The  steam  from  the  eduction -pipe  is  con- 
veyed through  two  coils  of  tubing  laid  in 
the  water  tank,  and  imparts  a  consider- 
able degree  of  heat  to  the  water  before  it 


is  transferred  to  the  boiler.  The  feed 
pump  is  equal  to  the  supply  of  from  20  to 
25  cubic  feet  of  water  per  hour. 

The  steam  is  got  up  (in  20  minutes.) 
and  the  pressure  in  the  boiler  is  at  70  lbs. 
the  square  inch.  The  height  to  which 
the  water  is  ejected  is  not  less  than  from 
115  to  120  feet.  The  number  of  strokes 
per  minute  is  18,  which  gives  for  the 
quantity  of  water  thrown  1  ton  7  cwt. 
13  lbs.  per  minute. 

The  water  cylinder  being  10i  in  dia- 
meter, the  area  of  the  water  piston  must 
be  86-6  square  inches ; 

And  a  14- inch  stroke  of  the  engine 
gives  for  the  length  of  the  stroke  in  the 
water  cylinder  56  inches  ; 

Therefore,  86-6  X  56  =  4849-6  cubic 
inches  of  water  each  stroke  =  2-8  cub.  ft. 
Deduct  for  back-water  through  the  valves 
1  cub.  ft.,  leaves  for  the  efiectual  result 
2-7  cub.  ft. 

And,  multiplying  2-7  by  18,  the  num- 
ber of  strokes  per  minute,  we  have  48-6 
cubic  feet  per  minute  =  3037  lb.s  =  1  ton 
7  cwt.  18  lbs. 

Two  pipes  were  afterwards  substituted, 
of  7-8  inch  in  diameter ;  then  four  of  5-8 
inch  in  diameter;  and  the  effects  pro- 
duced in  each  instance  was  as  nearly  as 
possible  equivalent  to  that  obtained  by 
the  1\  inch  jet. 

The  average  working  power  of  the  en- 
gine is  between  80  ana  90  tons  of  water 
per  hour. 

The  consumption  of  coke  is  about  three 
bushels. 

For  the  supply  of  the  great  quantity 
of  water  necessary  for  the  engine,  cast- 
iron  suction-pipes  are  to  be  laid  under 
the  pavement,  with  plugs  to  which  the 
suction  of  the  engine  may  be  fixed.  In 
consequence  of  this  arrangement,  the  en- 
gine may  be  used  as  well  for  extinguish- 
ing fire  itself  as  for  supplying  other  en- 
gines with  water.  As  there  are  400  ft.  of 
hose  belonging  to  it,  the  water  may  even 
by  that  means  be  conveyed  to  great  dis- 
tances ;  and  a  large  plane  may  be  protect- 
ed by  placing  the  engine  into  a  circle,  the 
radius  of  which  is  400  feet.  This  power- 
ful engine  requires  an  engineer,  a  stoker, 
and  1  to  4  men  to  attend  to  the  hose.  It 
saves  the  strength  of  42  to  105  men,  ac- 
cording to  its  size  from  6  to  15  horse 
f)ower.  It  does  not  tire,  works  regu- 
arlv,  and  requires  no  relief. 

Cooper's  Jiotatory  Fire   Engine  is  on 

the  rotative  principle,  worked  by  16  men, 

with  11  inch  lever.    It  discharges  through 

a  4  inch  pipe,  more  water  than  three  8 

,  inch    cylinders,    with    9    inch    strokes, 


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CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


171 


and  15  inch  lover,  worked  by  34  men — 
and  as  much  water  as  four  61  inch  cylin- 
ders, 9  inch  strokes,  worked  by  36  men 
with  24  inch  lever.  This  experiment 
was  made  at  New-York,  in  September, 
1827.  The  same  engine  with  12  men,  11 
inch  lever,  threw  more  water  than  2  en- 
gines, worked  by  36  men,  with  24  inch 
lever. 

A  rotative  engine,  with  20  men,  exert- 
ing an  estimated  power  of  35  lbs.  per 
man,  with  7  inch  lever,  has  thrown  from 
an  inch  pipe,  156  ft.  horizontal,  and  109 
ft.  in  height. 

A  rotative  engine,  with  8  men,  exert- 
ing an  estimated  power  of  50  lbs.  per 
man,  has  thrown  from  a  half-inch  pipe, 
148  ft.  horizontal,  and  103  ft.  in  height. 

The  quantity  of  water  discharged  by 
the  first  engine  was  525  gallons  for  each 
1  to  revolutions.  By  the  second,  304  gal- 
lons, each  100  revolutions.  By  the  third, 
128  gallons,  each  100  revolutions. 

In  the  first  engine  the  revolving  cylin- 
der was  13  inches  long  and  8  inches  in 
diameter,  and  the  surface  acting  upon 
the  water  was  40  square  inches.  In  the 
second  the  revolving  cylinder  was  12 
inches  long  and  6i  inches  in  diameter, 
and  it  had  a  surface  of  30  square  inches. 
The  third  cylinder  was  9  inches  long,  5 
inches  in  diameter,  and  18  square  inches 
acting  surface. 

It  raised  double -the  quantity  of  water, 
since  in  working  the  old  engines,  to  dis- 
charge the  chamber  or  cylinder  once,  the 
piston  must  pass  twice  through  it;  an 
ascending  stroke  to  create  a  vacuum, 
and  a  descending  one  to  force  the  water. 
Half  the  time  is  consequently  lost.  In  the 
rotative,  a  continued  vacuum  is  created, 
and  a  continued  discharged  effected. 
>  It  works  with  one-half  the  power, 
since  the  air-vessel  is  totally  dispensed 
with ;  and  the  power  is  applied  directly 
upon  the  water.  It  operates  on  no  more 
than  it  discharges.  On  the  other  hand, 
as  a  consequence  of  the  alternating  mo- 
tion of  the  piston  engines  twice  the  sur- 
face is  acted  on,  and  the  friction  of  course 
is  comparatively  twofold. 

FIEE  ESCAPE.  Any  machine  or  ap- 
paratus for  the  purpose' of  enabling  per- 
sons to  escape  from  the  upper  stories  of 
houses  on  fire.  The  contrivances  which 
have  been  proposed  for  accomplishing 
this  desirable  object  are  very  numerous, 
and  are  of  two  kinds  ;  the  first  kind  com- 
prising those  by  means  of  which  the 
escape  is  effected  without  external  aid, 
and  the  second  those  requiring  the  as- 
sistance of  persons  without.    Of  the  first 


kind  the  most  obvious  is  a  rope-ladder, 
which  may  be  kept  in  a  sleeping  apart- 
ment, and  used  upon  occasion  by  fasten- 
ing one  end  of  it  to  a  window-sill  or  bed- 
post. Mr.  Maseres  contrived  an  apparatus 
which  consists  of  a  long  rope  and  an  as- 
semblage of  cordage  or  belts,  so  disposed 
as  to  form  a  seat;  the  person  about  to 
descend  binds  himself  into  the  seat,  and 
then  lowers  himself  to  the  ground  by  al- 
lowing the  rope  which  is  fastened  to  the 
window-sill  to  slide  slowly  through  his 
hands ;  and  in  order  that  this  may  be 
done  easily,  the  rope  is  made  to  pass 
through  a  series  of  holes  in  a  block.  But 
unfortunately  contrivances  of  this  kind 
can  rarely  be  expected  to  be  of  any  use ; 
for  supposing  them  at  hand  when  the 
alarm  of  danger  is  given,  few  persona 
can  command  the  coolness  and  attention 
which  are  requisite  for  fixing  and  adjust- 
ing the  apparatus ;  and  even  then  it  is 
only  the  strong  and  active  who  could 
safely  descend  by  such  means  from  a 
considerable  height. 

With  regard  to  escapes  of  the  second 
kind,  the  object  is  to  enable  persons 
without  to  establish  speedily  a  commu- 
nication with  an  upper  room,  so  as  to 
afford  the  inmates  the  means  of  safe  de- 
scent ;  or  to  remove  them  if  necessary, 
as  in  the  case  of  the  feeble  or  children. 
A  very  portable  sort  of  ladder,  invented 
by  Mr.  Young,  is  described  in  the  Trans- 
actions of  the  Society  of  Arts  for  1 813.  It 
consists  of  a  number  of  cross  bars  or 
rounds,  connected  with  ropes,  which 
form  the  sides  of  the  ladder ;  the  end  of 
the  rounds  are  fitted  into  each  other,  so 
as  to  form  a  pole,  which  is  readily  ele- 
vated to  a  window ;  and  at  the  extremity 
is  an  iron  frame  terminating  in  hooks 
which  can  be  lodged  in  the  window-sill. 
When  the  hooks  are  properly  fixed,  a 
sudden  jerk  suffices  to  separate  the 
rounds,  which  immediately  fall  into  their 
places  when  the  ladder  is  formed  and 
suspended  from  the  frame.  But  this  ap- 
paratus only  answers  the  same  purpose 
as  a  rope-ladder,  and  is  therefore  liable 
to  the  same  objections.  Mr.  Brady's  fire- 
escape,  described  in  the  34th  vol.  of  the 
same  Transactions,  consists  of  a  car  oi 
cradle,  which  is  made  to  slide  on  a  slip  of 
plank  fixed  to  a  pole,  and  is  governed  by 
a  rope.  Mr.  Ford's  escape  consists  of  a 
spar  of  timber  about  35  or  40  feet  long, 
having  two  projecting  arms  at  the  top 
furnished  with  prongs,  by  which  a  firm 
bearing  against  the  wall  of  a  house  is  ob- 
tained. A  grooved  pulley  is  mortised 
into  the  spar  near  the  top,  and  another 


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CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[fir 


near  the  bottom  ;  over  the  pulleys  runs 
an  endless  rope,  to  which  is  attached  at 
one  point  a  main  rope,  and  at  another 
the  semicircular  brace  of  a  large  grooved 
roller,  which  traverses  up  and  down  the 
space  between  the  pulleys.  This  brace 
carries  on  the  under  side  of  the  spar  a 
hook,  to  which  a  cradle  is  attached, 
whereby  persons  can  be  easily  lowered 
to  the  ground. 

FIRE,  GREEK.  This  fire,  which  was 
employed  in  the  wars  of  the  Christians 
ana  Saracens  in  the  middle  ages,  is  said 
to  have  been  invented  during  the  reign 
of  Constantine  Pogonatus  in  the  year 
668  by  Callinicus,  an  architect  of  Helio- 
polis.  Naphtha  was  probably  is  princi- 
pal ingredient,  which,  if  skilfully  pro- 
jected and  inflamed,  creates  great  havoc 
and  dismay,  in  consequence  of  its  ex- 
treme combustibility  and  the  difficulty  of 
quenching  its  flame. 

FIRE-LOCK,  or  FUSIL.  A  musket 
or  small  gun,  which  is  fired  with  a  flint 
and  steel;  and  thereby  distinguished 
from  the  old  musket,  or  match-lock, 
which  was  fired  with  a  match.  The  date 
of  the  invention  of  fire-locks  is  uncertain. 

FIRE- WORKS.  Artificial  preparations 
made  of  gunpowder,  sulphur,  and  other 
inflammable  ingredients,  displayed  at 
public  rejoicings  and  on  other  occasions. 
(See  Pybotechny.) 

FISH-HOOKS,  are  constructed  with 
simple  tools,  but  require  great  manual 
dexterity  in  the  workmen.  The  iron 
wire  of  which  they  are  made  should  be 
of  the  best  quality,  smooth,  and  sound. 
A  bundle  of  such  wire  is  cut  in  lengths, 
either  by  shears  or  by  laying  it  down 
upon  an  angular  wedge  of  hard  steel 
fixed  horizontally  in  a  block  or  anvil,  and 
striking  off  the  proper  lengths  by  the 
blows  of  a  hammer.  In  fashioning  the 
barbs  of  the  hooks  the  straight  piece  of 
wire  is  laid  down  in  the  groove  of  an 
iron  block  made  on  purpose,  and  is  dex- 
terously struck  by  the  chisel  in  a  slant- 
ing direction,  across  so  much  of  the  wire 
as  may  be  deemed  necessary.  A  sharp- 
pointed  little  wedge  is  thus  formed, 
whose  base  graduates  into  the  substance 
of  the  metal. 

The  end  of  the  wire  where  the  line  is 
to  be  attached  is  now  flattened  or  screw- 
tapped  ;  the  other  end  is  sharp-pointed, 
and  the  proper  twisted  curvature  is  given. 
The  soft  iron  hooks  are  next  case-hard- 
ened, to  give  them  the  steely  stiffness 
and  elasticity,  by  imbedding  them  in 
animal  charcoal  contained  in  an  earthen 
or  iron  box;  (s^Case-Hardening;)  after 


which  they  are  brightened  by  heating 
and  agitating  them  with  bran,  and  finally 
tempered  by  exposure  to  a  regulated  tem- 
perature upon  a  hot  iron  plate.  Hooks 
for  salt-water  fishing  are  frequently 
tinned,  to  prevent  them  wearing  rapidly 
away  in  rust.     {See  Tin  Plate.) 

FIXED  OILS.  There  are  two  speci- 
mens of  oil  in  vegetables,  agreeing  in  the 
common  properties  of  unetuosity  and  in- 
flammability, but  essentially  different  in 
many  of  their  chemical  qualities.  The 
one  capable  of  being  volatilized  without 
decomposition,  is  named  volatile  oil,  the 
other  is  fixed  oil. 

The  latter  is  generally  contained  in  the 
seeds  and  fruits  of  vegetables,  and  varies 
in  its  properties,  according  to  the  plants 
from  which  it  is  obtained  by  pressure, 
and  frequently  called  expressed  oils. 
When  the  process  is  aided  by  heat,  the 
action  of  which  is  to  render  the  oil  more 
fluid,  the  product  is  esteemed  less  pure. 
The  purest  fixed  oils  are  those  expressed 
from  the  fruit  of  the  olive,  or  the  seeds  of 
the  almond ;  others,  less  pure,  come  from 
the  flax-seed  and  hemp-seed.  These  oils 
are  usually  fluid,  but  of  a  somewhat  thick 
consistence,  and  liable  to  congeal  at  very 
moderate  colds  ;  palm-oil  is  even,  na- 
turally, concrete.  When  fluid,  they  are 
transparent,  of  a  yellow  or  yellowish- 
green  color,  and  capable  of  being  render- 
ed quite  transparent  by  the  use  of  animal 
charcoal.  They  are  inodorous  and  in- 
sipid, at  least  if  they  have  been  obtained 
with  due  care ;  and  free  from  the  muci- 
laginous and  extractive  matter  of  the 
f)lants  from  whence  they  come  ;  are 
ighter  than  water,  with  which  they  do 
not  unite,  and  are  very  sparingly  soluble 
in  alcohol,  with  the  exception  of  castor- 
oil.  At  a  temperature  below  600°  Fahr., 
they  remain  unchanged. 

Near  this  temperature,  however,  they 
begin  to  boil,  and  to  disengage  an  in- 
flammable vapor;  but  the  oil  thus  con- 
densed is  altered  in  its  properties ;  it 
loses  its  mildness,  becomes  more  limpid 
and  volatile,  a  portion  of  carbon  being 
likewise  deposited.  Transmitted  through 
an  ignited  tube,  fixed  oil  is  convert  id 
into  carbonic  acid  and  carbureted  hydro- 
gen, with  a  small  portion  of  acid  liquor, 
and  a  residuum  of  charcoal.  In  the 
open  air,  it  burns  with  a  clear  white 
light,  and  formation  of  water  and  car- 
bonic acid  gas.  Accordingly,  the  fixed 
oils  are  capable  of  being  employed  for 
the  purposes  of  artificial  illumination,  as 
well  in  lamps  as  for  the  manufacture  of 
|  gas.      Fixed  oils   undergo  considerable 


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CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


173 


change  by  exposure  to  the  air.  The  ran- 
cidity which  then  takes  place  is  occa- 
sioned by  the  mucilaginous  matters 
which  they  contain  becoming  acid. 

From  the  operation  of  the  same  cause, 
they  gradually  lose  their  limpidity,  and 
some  of  them,  which  are  hence  called 
drying-oils,  become  so  dry,  that  they  no 
longer  feel  unctuous  to  the  touch,  nor 
give  a  stain  to  paper.  This  property,  for 
which  linseed-oil  is  remarkable,  may  be 
communicated  quickly,  by  heating  the 
oil  in  an  open  vessel.  The  drying-oils 
are  employed  for  making  oil-paint,  and, 
mixed  with  lamp-black,  constitute  print- 
ers' ink. 

During  the  process  of  drying,  oxygen 
is  absorbed  in  considerable  quantity. 
This  absorption  of  oxygen  is,  under 
certain  circumstances,  so  abundant  and 
rapid,  and  accompanied  with  such  a  free 
disengagement    of    caloric,    that    light, 

Jjorous,  combustible  materials,  such  as 
amp-black,  hemp,  or  cotton-seed  may 
be  kindled  by  it.  Many  instances  of 
spontaneous  combustion  have  occurred 
from  this  cause.  It  appears  that  if  hemp, 
flax,  or  linen  cloth,  steeped  in  linseed- 
oil,  lie  in  a  heap,  and  be  somewhat  press- 
ed together  and  confined,  its  temperature 
rises,  a  smoke  issues  from  it,  and,  at 
length,  sometimes  within  24  or  even  12 
hours,  it  takes  fire.  The  same  thing 
happens  with  mixtures  of  oil  and  fine 
charcoal,  and  with  lamp-black  wrapped 
up  in  linen ;  from  whence  it  is  conjec- 
tured, that  many  extensive  fires,  which 
have  broken  out  in  cotton  manufactories, 
and  for  which  no  cause  could  be  assigned, 
must  have  arisen  from  this  spontaneous 
inflammability  of  oils. 

Fixed  oils  unite  with  the  common  me- 
tallic oxides.  Of  these  compounds,  the 
most  interesting  is  that  with  the  oxide 
of  lead.  When  linseed-oil  is  heated  with 
a  small  quantity  of  litharge,  a  liquid  re- 
sults which  is  powerfully  drying,  and  is 
employed  as  oil-varnish.  Olive-oil,  com- 
bined with  half  its  weight  of  litharge, 
forms  the  common  diachylon  plaster.  The 
fixed  oils  arc  readily  attacked  by  alkalies. 
With  ammonia,  they  form  a  soapy  liquid, 
to  which  the  name  of  volatile  liniment  is 
applied. 

They  are  oxidated  by  a  number  of  the 
acids.  Sulphuric  acid  soon  renders  them 
black  ;  the  oxygen  of  the  acid  attracting 
part  of  the  hydrogen  of  the  oil,  and 
causing  the  deposition  of  charcoal ;  and, 
if  heat  is  applied,  a  large  portion  of  sul- 
phurous acid  is  disengaged,  and  even 
sulphur  is  evolved.    Nitric  acids  renders 


them  thick ;  if  heat  is  applied,  the  action 
is  more  rapid,  and  a  yellow  color  is  com- 
municated, the  oil  being  rendered  con- 
crete. Chlorine  thickens  oil,  and  renders 
it  white.  When  boiled  in  sulphur,  a 
compound  is  formed  of  a  brown  color,  a 
very  fetid  smell,  and  acrid  taste.  It  like- 
wise, when  heated,  dissolves  phosphorus, 
forming  a  liquid  which  becomes  lumi- 
nous, when  exposed  to  the  air.  Olive- 
oil  consists  of  carbon77'213,  oxygen  9-427, 
and  hydrogen  13-360. 

FLAKE  WHITE,  is  the  name  some- 
times given  to  pure  white-lead. 

FLAME,  is  the  combustion  of  an  ex- 
plosive mixture  of  an  inflammable  gas  or 
vapor  with  air.  That  it  is  not,  as  many 
suppose,  combustion  merely  at  the  ex- 
terior surface,  is  proved  by  plunging  a 
fragment  of  burning  phosjiiorus  or  sul- 
phur into  the  centre  of  a  large  flame  of 
alcohol.  Either  of  these  bodies  will  con- 
tinue to  burn  there  with  its  peculiar 
light ;  thus  proving  that  oxygen  is  mixed 
with  the  whole  of  the  burning  vapor.  If 
we  mix  good  coal  gas  with  as  much  at- 
mospheric air  as  can  convert  all  its  carbon 
into  carbonic  acid,  the  mixture  will  ex- 
plode with  a  feeble  blue  light ;  but  if  we 
mix  the  same  gas  with  a  small  quantity 
of  air,  it  will  burn  with  a  rich  white 
flame.  In  the  latter  case  the  carbona- 
ceous particles  are  precipitated,  as  Sir  H. 
Davy  first  showed,  in  the  interior  of  the 
flame,  become  incandescent,  and  consti- 
tute white  light :  for  from  the  ignition 
of  solid  matter  alone  can  the  prismatic 
rays  be  emitted  in  that  concentrated 
union.  Towards  the  interior  of  the  flame 
of  a  candle,  a  lamp,  or  a  gas  jet,  where 
the  air  is  scanty,  there  is  a  deposition  of 
solid  charcoal,  which  first  by  its  ignition, 
and  afterwards  by  its  combustion,  in- 
creases in  a  high  degree  the  intensity  of 
the  light.  If  we  hold  a  piece  of  fine  wire 
gauze  over  a  jet  of  coal  gas  close  to  the 
orifice,  and  if  we  then  kindle  the  gas,  it 
will  burn  above  the  wire  with  its  natural 
brilliancy ;  but  if  we  elevate  the  gauze 
progressively  higher,  so  as  to  mix  more 
and  more  air  with  it  before  it  reaches 
the  burning  point,  its  flame  will  become 
fainter  and  less  white.  At  a  certain  dis- 
tance it  becomes  blue,  like  that  of  the 
above  explosive  mixture.  Since  the  com- 
bustion of  all  the  constituents  is  in  this 
case  direct  and  complete,  the  heat  be- 
comes greatest  in  proportion  nearly  as 
the  light  is  diminished.  If  a  few  platina 
wires  be  held  in  that  dim  flame  they  will 
grow  instantly  white  hot,  and  illuminate 
the  apartment.    On  reversing  the  order 


174 


CYCLOPEDIA    OF  THE   USEFUL   ARTS. 


[fla 


of  this  experiment,  by  lowering  progres- 
sively a  fhuxpiece  of  wire  gauze  from  the 
summit  towards  the  base  of  a  gas  flame, 
we  shall  And  no  charcoal  deposited  at  its 
top,  because  plenty  of  air  has  been  intro- 
duced there  to  convert  all  the  carbon  of 
the  gas  into  carbonic  acid,  and  therefore 
the  apex  is  blue ;  but  as  we  descend, 
more  and  more  charcoal  will  appear  upon 
the  meshes.  At  the  very  bottom,  in- 
deed, where  the  atmospheric  air  impinges 
upon  the  gauze,  the  flame  is  again  blue, 
and  no  charcoal  can  therefore  be  depo- 
sited. 

The  fact  of  the  increase  of  the  bril- 
liancy and  whiteness  of  flame  by  the  de- 
velopment and  ignition  of  solid  matter 
in  its  bosom  illustrates  many  curious 
phenomena.  We  can  thus  explain  why 
olefiant  gas  affords  the  most  vivid  illumi- 
nation of  all  the  gases  ;  because,  being 
surcharged  with  charcoal,  its  hydrogen 
lets  it  go  in  the  middle  of  the  name,  as 
it  does  in  an  ignited  porcelain  tube, 
whereby  its  solid  particles  first  get  igni- 
ted to  whiteness,  and  then  burn  away. 
When  phosphorus  is  inflamed  it  always 
yields  a  pure  white  light,  from  the  igni- 
tion of  the  solid  particles  of  the  snowy 
acid  thus  produced. 

In  the  blowpipe  the  inner  blue  flame 
has  the  greatest  heat,  because  there  the 
combustion  of  the  whole  fatty  vapor  is 
complete.  The  feeble  light  of  burning 
hydrogen,  carbonic  oxide,  and  sulphur, 
may,  upon  the  principles  now  expound- 
ed, be  increased  by  simply  placing  in 
them  a  few  particles  of  oxide  of  zinc, 
slender  filaments  of  amianthus,  or  fine 

f)latina  wire.  By  narrowing  the  top  of  a 
ong  glass  chimney  over  anargand  flame 
either  from  oil  or  coal  gas,  the  light  can 
be  doubled  at  the  same  cost  of  material. 
The  very  tall  chimneys  used  by  the  Pa- 
risian lampists  are  very  wasteful.  The 
light  of  a  name  may  be  increased  by  di- 
minishing its  heat,  or  the  intensity  of  its 
combustion  ;  and  conversely  the  heat  of 
flame  may  be  increased  by  diminishing 
its  light. 

FLATTING.  In  architecture,  a  coat 
of  paint,  which,  from  its  mixture  with 
turpentine,  leaves  the  work  flat,  or  with- 
out gloss. 

FLAX.  An  annual  plant,  the  Imum 
usitatiwimum,  grown  extensively,  from 
remote  antiquity,  over  Europe,  Asia,  and 
Northern  Africa.  It  is  believed  to  be 
indigenous  to  Persia.  It  rises  between 
two  and  three  feet  high,  and  is  chiefly 
grown  either  for  the  seeds,  which  lie  in 
capsules  of  ten  cells,  each  cell  containing 


one  seed,  or  for  the  fibre  yielded  by  the 
bark,  of  which  linen  cloth  is  made.  The 
use  of  linen  is  so  ancient  that  there  is  no 
tradition  of  its  introduction.  The  Scan- 
dinavian and  other  northern  tribes  knew 
its  use,  and  the  mummies  of  Egypt  are 
covered  with  it.  Immense  quantities 
arc  still  made  at  the  mouth  of  the  Nile, 
where  it  forms  almost  the  sole  clothing. 
It  supplies  most  of  Africa  and  Italy  to  a 
great  extent.  From  Egypt  its  use  passed 
into  Greece,  and  thence  into  Italy.  Be- 
sides being  used  as  apparel,  the  rags 
when  worn  out  and  made  into  a  paste, 
are  converted  into  paper.  The  seeds 
of  the  flax  are  mucilaginous  and  emollient, 
and  an  infusion  constitutes  a  medicinal 
drink.  They  also  yield  an  oil,  well 
known  in  commerce  as  Unseed  oil,  which 
differs  from  most  expressed  oils,  as  in 
congealing  in  water,  and  not  forming  a 
solid  soap  with  fixed  alkaline  salts.  The 
oil  has  no  remarkable  taste,  and  is  used 
in  lamps,  and  occasionally  in  cookery, 
and  also  forms  the  base  of  all  the  oily 
varnish  made  in  imitation  of  China  var- 
nish. It  is  much  used  in  coarse  painting, 
as  where  there  is  not  much  exposure  to 
weather.  Lime  water  and  linseed  oil 
constitutes  one  of  the  best  applications 
to  recent  burns.  The  cakes  which  re- 
main after  the  oil  is  expressed  are  used 
for  fatting  cattle  and  sneep,  for  which 
they  are  very  serviceable  :  they  are  occa- 
sionally used  as  manure.  Flax-seed  has 
been  used  instead  of  cereal  grains  in 
years  of  scarcity,  but  it  is  a  heavy  and 
unwholesome  food. 

By  attention  and  careful  cultivation 
good  flax  may  be  grown  on  various  soils  : 
the  soil  best  suited  is  a  sound,  dry,  deep 
loam,  with  a  clay  subsoil.  Draining  is 
almost  necessary  for  flax  lands,  for  on 
too  damp  grounds  good  flax  will  not 
grow.  In  Flanders  flax  is  grown  in  the 
year  of  a  seven  course  shift,  or  the  fifth 
year  of  a  ten  course  shift.  It  is  hardly 
advisable  to  cultivate  it  more  frequently 
than  once  in  seven  years.  It  is  usually 
grown  after  a  grain  crop,  as  oats  coming 
after  old  lea,  or  a  green  crop ;  or  it  grows 
well  after  potatoes  coming  after  lea.  The 
ground  should  be  ploughed  two  or  three 
times,  once  in  autumn  and  twice  in 
spring;  it  should  be  harrowed  twice 
early  in  spring,  to  bring  the  land  into 
good  tilth,  and  clean  it  thoroughly  from 
weeds  and  roots.  The  Kiga  and  Dutch 
seeds  produce  the  finest  flax.  The  seed 
of  this  country,  though  it  gives  an  abun- 
dant crop,  yet  produces  a  coarse  branchy 
stem,  and  should  only  be  used  on  deep 


fla] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


175 


loamy  soils.    Two  "bushels,   or  a  little 
over  per  acre,  is  the  fair  quantity  for  sow- 
ing.   It  is  better  to  sow  thickly,  for  the 
stems  grow  taller  and  straighter,  with 
only    two    seed    capsules    rt    top,    and 
the   fibre  is    superior    in    fineness   and 
length.    Grass-seed  and   clover    should 
not  be  sown  with  it,  but  carrots  may  be 
drilled  in  between  the  rows,  if  flax  be  so 
sown.    The  ground  should  be  wed  fre- 
quently, and  pulled  carefully.    The  best 
time  for  pulling  is  before  the  seed  is 
quite  ripe ;  if  pulled  two  soon  there  is 
Waste  in  the  after  preparation ;    if  too 
late,  the  fibre  is  coarse.     When  the  seeds 
begin    to    change    from    green   to    pale 
brown,  then  the  flax  should  be  pulled. 
The   separation    of  the   seed  from  the 
stem   is  called  rippling.    It  should   be 
done  on  the  field,  and  the  ripple  is  a 
comb  or  row  of  iron  teeth  screwed  into  a 
block  of  wood;    this    is  screwed  on  a 
plank    resting    on    stools.    A    sheet    is 
spread  underneath,  and  by  drawing  the 
flax  across  the  comb,  the  seeds  are  sepa- 
rated, and  fall  upon  the  sheet ;  these  are 
afterwards  riddled  and  fanned,  to  sepa- 
rate chaff,  &c,  and  then  dried.     Hereto- 
fore flax  has  hecn  prepared  by  cold  steep- 
ing in  river  water,  the  flax* being  fully 
immersed.    Here  the  soft  parts  of  the 
plant  ferment,   and  the  fibre  separates 
away.    The  time  of  steeping  varies  from 
eight  tc   fourteen   days.     The  plant  is 
then  removed,   and  spread  on  grass  to 
dry.     It   is    now  fit   tor    breaking    and 
skutching.    The  treatment  of  flax  and 
hemp  should  be  carried  on  alike,  the 
fibre  of  both  being  capable  of  being  ob- 
tained in  same  way.    There  can  be  no 
doubt  that  chemical  processes,  and  steam 
with  warm  water,  will  completely  super- 
sede the  cold  water  and  grass  processes. 
Breaking  is    sometimes    performed    by 
beating  the  flax  with  the  hand  and  ham- 
mer, which  bruises  the  wood  and  sepa- 
rates the  fibres;  a  rude  machine,  called 
a  hand-brake,  is  sometimes  used  for  this 
purpose.    The  machines  do  this  work 
more  effectually.    They  consist  of  many 
deeply  fluted  rollers   of  wood  or  iron, 
whose  teeth  work  into  each  other,  and 
thus  break  the  wood  across,  while  the 
yielding  fibre  is  not  injured. 

By  the  operation  of  heckling  a  three- 
fold object  is  gained.  1st.  The  parting  j 
of  the  filaments  into  their  finest  fibrils  ;  j 
2d.  The  separation  of  short  fibrils,  which  | 
are  unfit  for  spinning ;  3d.  The  equable  i 
and  parallel  arrangements  of  long  fila-  j 
ments.  The  instrument  for  accomplish-  I 
ing  these  was  a  tool  called  the  heckle  ;  a 


surface  studded  more  or  less  thickly  with 
metal  points  called  heckle  teeth:  over 
which  the  flax  is  drawn  in  such  a  way 
that  the  above  three  required  operations 
may  be  properly  accomplished.  The 
operation  is  simple,  but  requires  expert- 
ness  to  work  well.  The  operative  seizes 
a  flock  of  flax  by  the  middle  with  the 
right  hand,  throws  it  on  the  points  of 
the  coarse  heckle,  and  draws  it  to  him, 
while  he  holds  the  left  hand  on  the  other 
side  of  the  heckle,  so  as  to  spread  the 
flax,  and  to  prevent  it  from  sinking  too 
deeply  among  the  teeth.  The  short  fibres, 
or  tow,  are  removed  occasionally.  When 
one  half  the  length  of  the  strake  of  flax 
is  heckled,  it  is  turned  to  heckle  the 
other  half.  100  lbs.  of  well  cleaned  flax, 
45  or  50  lbs.  of  heckled  flax,  may  be  ob- 
tained by  hand  labor  of  50  hours  ;  the 
rest  being  tow,  with  a  small  waste  of 
fibre  of  wood.  Machinery  has  not  yet 
heCn  made  to  effectually  supersede  hand 
labor  in  heckling.  To  aid  the  heckle  in 
splitting  the  filaments,  three  methods 
have  been  had  recourse  to.  1.  Beating, 
brushing,  and  boiling  with  soap  water  or 
an  alkaline  ley.  This  boiling  dissolves 
that  portion  of  the  glutinous  cement 
which  had  resisted  the  rotting,  and  com- 
pletes the  separation  of  the  fibres,  and  is 
an  excellent  plan  of  improving  flax.  ^Ma- 
chines driven  by  steam  "have  been 
employed  for  the  heckling,  combing, 
and  scutching  of  the  fibres.  Scutching 
is  effected  in  the  heckling  machine  by 
means  of  four  arms  projecting  from  a  ho- 
rizontal axle  arranged  so  as  to  strike  the 
boom  in  a  slanting  direction,  until  the 
hark  and  other  useless  parts  of  the  plant 
are  beaten  away. 

In  the  spinning  of  flax,  compared  with 
cotton  and  wool, It  possesses  several  cha- 
racteristic properties.  While  cotton  and 
wool  are  naturally  presented  as  insulated 
fibres,  the  former  requiring  to  be  merely 
separated  from  the  seed,  and  the  latter 
to  be  purified  before  delivery  to  the  spin- 
ner, flax  must  have  its  filaments  sepa- 
rated from  each  other  by  tedious  treat- 
ment. In  reference  to  the  spinning  and 
subsequent,  operations,  it  may  be  said 
that  good  flax  should  have  a  bright  silver 
gray,  or  yellow  color,  inclining  neither  tc 
green  or  black.  It  should  be  long,  firm, 
soft,  and  glistening,  like  silk,  and  contain 
no  broad,  tape-like  portions  from  undis- 
severed  filaments.  Tow  is  different  in 
having  shorter  fibres  of  very  unequal 
length,  and  entangled. 

The  manufacture  of  linen  and  hemp 
yarn,    and  the  tow  of  cither,   may  be 


176 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[fli 


effected  by  different  processes;  by  the 
distaff,  the  hand-wheel,  and  spinning  ma- 
chinery. In  the  language  or  flax  mills, 
the  flax  ceases  to  be  so  called  after  it  has 
passed  through  the  heckling  machine. 
The  great  portion  is  then  called  line,  and 
the  inferior  tow.  Both  of  these  are  after- 
wards spun  into  yarn,  but  the  yarn  so 
produced  has  different  degrees  of  excel- 
lence. Other  machines  are  used,  by  which 
tow  is  converted  into  slivers,  by  carding 
analogous  to  cotton  and  wool  processes. 

When  the  slivers,  whether  of  line  or 
tow,  have  been  brought  to  the  desired 
breadth,  thickness,  and  equality,  they 
are  carried  to  the  'roving  machines,' 
where  they  are  transformed  to  the  state 
of  a  soft,  small,  cylindrical  cord.  There 
are  two  combined  movements  whereby 
this  is  effected;  the  sliver  is  drawn  out 
or  elongated,  and  it  has  a  slight  twist 
imparted  to  it  as  a  means  of  enabling  it 
to  cohere  and  to  bear  the  subsequent  ac- 
tion of  the  spinning-machines. 

These  spinning-machines  we  have  next 
to  notice.  They  are  on  the  '  bobbin-and- 
fly '  principle ;  '  mule-spinning '  not  hav- 
ing, we  believe,  been  introduced  in  the 
flax  manufacture.  Flax,  unlike  cotton, 
silk,  wool,  or  worsted,  is  spun  wet,  as  a 
means  of  obtaining  a  finer  and  smoother 
yarn  ;  and  within  the  last  few  years  the 
use  of  warm  water,  instead  of  cold,  has 
been  introduced  for  this  purpose.  The 
same  flax,  prepared  in  the  same  way,  can  be 
spun  to  a  much  higher  number,  or  much 
greater  degree  of  fineness,  with  hot  wa- 
ter than  with  cold  ;  and  this  is  doubtless 
one  of  the  improvements  to  which  the 
recent  progress  of  the  flax  manufacture 
may  be  attributed.  The  spindles  by 
which  the  yarn  is  spun  revolve  some 
thousands  of  times  in  a  minute,  and  the 
wet  yarn  thus  throws  off  a  continuous 
spray  by  the  centrifugal  force  thereby  ge- 
nerated ;  the  girls  and  young  women  who 
attend  the  machines  wear  therefore  a 
thick  apron  to  protect  themselves  from 
the  spray.  The  water  is  contained  in  a 
kind  of  oblong  trough  attached  to  each 
machine,  and  steam  is  admitted  by  a 
small  pipe  as  a  means  of  bringing  the 
water  to  the  required  temperature. 

When  the  yarn  is  spun,  it  is  destined 
either  for  weaving  or  for  thread.  If  for 
weaving,  the  yarn  is  reeled  into  hanks  on 
a  hexagonal  reel,  to  be  afterwards  made 
up  into  bundles  of  twenty  hanks  each, 
containing  sixty  thousand  yards  ;  but  if 
the  yarn  is  to  be  made  into  thread,  it  is 
carried  to  other  machines,  by  means  of 
which  two  yarn-threads  are  twisted  to- 


gether, and  converted  into  the  hard  and 
firm  thread  used  in  needlework  and  lace- 
making. 

Here,  then,  the  operations  of  a  flax- 
mill  terminate.  If  the  flax-yarn  is  wov- 
en into  any  kind  of  linen  or  flaxen  fabric, 
that  is  an  additional  feature.  At  most 
flax-mills  the  operations  cease  when  the 
yarn  and  thread  are  produced. 

FLEXIBILITY.  That  property  of 
bodies  in  virtue  of  which,  when  a  suffi- 
cient force  is  applied  to  them,  they 
change  their  form,  and  are  bent.  Flexi- 
bility is  opposed  to  stiffness  on  the  one 
hand,  and  to  brittleness  on  the  other ; 
stiff  bodies  being  such  as  resist  bending, 
and  brittle  those  that  cannot  be  bent 
without  a  disruption  of  their  parts. 

FLINT.  Common  flints  are  nearly 
pure  silica.  They  usually  occur  in  irre- 
gular nodules  in  chalk.  Their  origin  is 
an  unsolved  geological  problem. 

FLINT  GLASS,  or  CKYSTAL.  A 
species  of  glass  which  derives  its  name 
from  flint,  because  that  substance  was 
formerly  employed  in  its  manufacture. 
It  is  very  extensively  used  for  domestic 
purposes  ;  but  is  chiefly  interesting  to 
the  philosopher  on  account  of  the  pro- 
perty which  it  possesses  of  causing  a 
greater  dispersion  of  the  rays  of  light 
which  pass  through  a  prism  or  lens  form- 
ed of  it  than  any  other  of  the  vitreous 
compounds.  This  property  renders  it 
invaluable  in  the  manufacture  of  the  ob- 
ject glasses  of  telescopes  and  micro- 
scopes ;  for  by  combining  a  concave  lens 
of  flint  glass  with  one  or  two  convex 
lenses  of  crown  glass,  which  possesses  a 
much  less  dispersive  power,  a  compound 
lens  is  formed,  in  which  the  prismatic 
colors  arising  from  a  simple  refraction  are 
destroyed,  and  the  lens  rendered  achro- 
matic. This  construction  of  object  glasses 
was  first  discovered  by  a  Mr.  Hall,  a  coun- 
try gentleman  in  Worcestershire,  about 
1729 ;  but  the  discovery  was  forgotten, 
and  no  farther  notice  taken  of  it  for  near- 
ly 30  years,  when  it  was  again  brought  to 
light  by  John  Dollond,  after  a  long-con- 
tinued course  of  experiments  under- 
taken for  the  purpose  of  perfecting  the 
telescope.  It  is,  however,  very  difficult 
to  prepare  flint  glass  fit  for  the  purposes 
of  achromatic  telescopes.  This  difficulty 
arises  not  from  the  want  of  sufficient  dis- 
persive power  in  the  substance,  but  from 
the  want  of  purity  or  homogeneity ;  the 
slightest  impurity  or  inequality  of  com- 
position in  the  glass  giving  rise  to  a 
streaked  or  imperfect  image  By  reason  of 
the  unequal  refraction  of  the  Kiys.    The 


FLO] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


Ill 


composition  of  pure  flint  glass  long  re- 
mained a  secret  in  the  family  of  the  Dol- 
londs,  and  its  manufacture  formed  a  very 
profitable  article  of  exportation  ;  for  till 
about  the  beginning  of  the  present  cen- 
tury, no  flint  glass  of  good  quality  was 
made  on  the  Continent.  Of  late  years, 
however,  a  great  change  has  taken  place 
in  this  respect,  and  glass  of  the  best 
quality  has  been  manufactured,  both  in 
France  and  Germany,  in  much  larger 
masses  than  the  English  artists  have  yet 
succeeded  in  obtaining.  This  result  has 
been  mainly  produced  by  the  experimen- 
tal researches  of  D' Artigues,  Fraunhofer, 
Cauchoix,  Guinand,  and  Korner.  For- 
merly, an  object-glass  exceeding  five 
inches  in  diameter  could  scarcely  be  pro- 
duced. Fraunhofer  succeeded  in  making 
them  of  nine,  and  even  twelve  inches. 
The  object-glass  of  the  large  parallactic 
telescope  belonging  to  Sir  James  South, 
at  Campden  Hill,  was  manufactured  by 
Cauchoix ;  it  exceeds  twelve  inches,  and 
is  throughout  of  the  utmost  purity.  The 
exact  proportion  of  the  ingredients  which 
enter  into  these  choice  specimens  is  not 
known,  and  probably  their  excellence  de- 
pends in  part  on  some  accidental  circum- 
stances in  the  preparation.  Korner  pro- 
duced some  of  his  best  specimens  by 
employing  the  following  ingredients : 
100  parts  of  quartz,  first  treated  with  mu- 
riatic acid ;  80  parts  of  litharge,  or  red 
lead ;  and  80  parts  of  the  bitartrate  of 
potash.  Flint  glass  for  common  pur- 
poses is  usually  made  of  120  parts  of  fine 
white  sand,  40  parts  of  well  purified 
pearl  ash,  35  parts  litharge  or  minium, 
13  parts  nitre,  and  a  small  quantity  of 
the  black  oxide  of  manganese  ;  the  latter 
ingredient  being  used  to  correct  the  green 
color  occasioned  by  the  presence  of  oxide 
of  iron  in  the  sand. 

FLINT-GRINDING  is  a  mechanical 
process  indispensable  in  the  manufacture 
of  earthenware  and  porcelain.  The  flint 
nodules,  derived  from  the  chalk  forma- 
tions, are  calcined  in  small  kilns  (formed 
similarly  to  lime-kilns).  While  hot  they 
are  thrown  beneath  the  stampers,  a  set  of 
vertical  beams,  whose  ends  are  shod  with 
iron,  and  which  are  lifted  up  by  the  crank 
or  shaft,  and  fall  on  the  nodules,  the 
fractured  portions  falling  through  a  grate. 

These  are  thrown  into  a  circular  vat, 
10  to  15  feet  in  diameter,  the  bottom  pav- 
ed with  blocks  of  chert-stone,  the  horn- 
stone  of  Jameson.  In  a  step  in  the  cen- 
tre is  placed  the  axis  of  a  vertical  strong 
wooden  shaft,  on  the  upper  end  of  which 
is  a  crown  spur-wheel,  lor  the  requisite 
8* 


motion  from  a  steam-engine  or  water- 
wheel.  At  right  angles  this  shaft  has 
an  arm,  each  with  a  ledge,  to  bear  other 
blocks  of  chert.  The  whole  being  put  in 
motion,  the  abrasure  of  the  calcined  flints" 
is  promoted  by  that  of  the  chert  among 
the  water,  and  is  continued  until  the  mass 
is  a  pulpy  fluid,  and  a  pint  measure  of  it 
weigns  not  less  than  32  oz.  The  Cor- 
nish stone  is  ground  in  a  similar  manner, 
and  the  pulpy  fluid  is  not  less  than  33  oz. 
the  pint  measure.  One  ton  of  good  nod- 
ules should  grind  into  120  pecks  of  flint 


*ti 


Flints  are  also  reduced  to  fine  powder, 
by  heating  them  red  hot  and  quenching 
them  in  water. 

FLOAT  BOAEDS.  The  boards  fixed 
to  the  rim  or  outer  circumference  of  un- 
dershot wheels,  which  receive  the  im- 
pulse of  the  water  and  communicate  the 
motion  to  the  wheel. 

FLOATED  LATH  AND  PLASTER. 
In  architecture  plastering  of  three  coats, 
whereof  the  first  is  pricking  up ;  the 
second,  floating  or  floated  work  ;  and  the 
last  of  fine  stvff. 

FLOATED  WORK.  In  architecture, 
plastering  made  of  a  perfectly  plane  sur- 
face, by  means  of  a  tool  (which  is  a  long 
rule  with  a  straight  edge)  called  a  float. 

FLOATING  MEADOWS.  Meadow 
lands,  the  surface  of  which  is  flat,  ad- 
joining a  river  or  other  source  of  water, 
with  which  they  can  be  flooded  or  cover- 
ed at  pleasure.  ^  The  water  is  turned  on 
chiefly  in  the  winter  season,  when  it  is 
more  or  less  muddy,  and  leaves  a  deposit 
that  serves  as  a  kind  of  manure.  It  is 
also  useful  to  vegetation,  by  preserving  a 
higher  temperature  in  the  surface  soil 
than  it  could  maintain  through  the  win- 
ter, if  fully  exposed  to  the  action  of  the 
atmosphere;  because,  wherever  water  is 
in  a  fluid  state,  its  mean  temperature,  and 
that  of  the  bodies  immediately  in  contact 
with  it,  must  be  above  32°,  and  at  that 
temperature  the  grasses  common  in  Bri- 
tish meadows  will  grow.  There  are  pro- 
bably other  benefits  which  grass  lands 
receive  from  being  covered  with  water 
during  a  portion  of  the  winter  season, 
but  these  have  not  yet  been  satisfactorily 
explained  by  science. 

FLOATING  SCREEDS.  In  architec- 
ture, strips  of  plaster  arranged  and  nicely 
adjusted  for  guiding  the  floating-rule. 
See  Floated  Work. 

FLOATSTONE.  A  porous  variety  of 
flint,  which  floats  upon  water. 

FLOSS-SILK  is  the  name  given  to  the 
portions  of  ravelled  silk  broken  off  in  the 


178 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[flu 


filature  )f  the  cocoons,  which  is  carded 
like  cot  *>n  or  wool,  and  spun  into  a  soft 
coarse  J  arn  or  thread,  for  making  bands, 
shawls,  30cks,  and  other  common  silk  fa- 
brics. The  floss  or  fleuret,  as  first  ob- 
tained, must  be  steeped  in  water,  and 
then  subjected  to  pressure,  in  order  to 
extract  the  gummy  matter,  which  renders 
it  too  harsh  and  short  for  the  spinning- 
wheel.  After  being  dried,  it  is  made  still 
more  pliant  by  working  a  little  oil  into  it 
with  the  hands.  It  is  now  ready  to  be 
Bubmitted  to  the  carding  engine.  It  is 
spun  upon  the  flax  wheel. 

FLOUR  OF  WHEAT  (Adultera- 
tions of,  to  detect).  The  first  method 
is  by  specific  gravity.  If  potato  flour  be 
added,  which  is  frequently  done  in  France, 
since  a  vessel  which  contains  one  pound 
of  wheat  flour  will  contain  one  pound  and 
a  half  of  the  fecula,  the  proportion  of 
ibis  adulteration  may  be  easily  estimated. 
2f  gypsum  or  ground  bones  be  mixed 
with  the  flour,  they  will  not  only  increase 
its  density  still  more,  but  they  will  re- 
main after  burning  away  the  meal. 

The  second  method  is  by  ascertaining 
the  quantity  of  gluten  which  the  suspect- 
ed sample  will  afford,  by  the  process  pre- 
scribed under  the  article  Bread.  The  two 
following  chemical  criteria  may  also  be 
employed. 

1st.  Nitric  acid  has  the  property  of 
coloring  wheat  flour  of  a  fine  orange  yel- 
low, whereas  it  affects  the  color  neither 
of  fecula  nor  starch. 

2d.  Pure  muriatic  acid  colors  good 
wheat  flour  of  a  deep  violet,  but  dissolves 
fecula  or  starch,  and  forms  with  it  a  light, 
eolorless,  viscous  fluid,  decomposable  by 
alkalis.  It  may  also  be  observed,  that  as 
fecula  absorbs  less  water  than  flour,  this 
affords  a  ready  means  of  detection. 

The  adulteration  with  bean  or  pea  flour 
may  be  detected  by  pouring  boiling  water 
upon  it,  which  developes  the  peculiar 
smell  of  these  two  substances. 

FLOWERS  (Artificial).  The  art  of 
representing  by  flowers,  leaves,  plants, 
&c,  vegetable  nature  in  her  ornamental 
productions,  constitutes  the  business  of 
the  artificial  florist.  The  Italians  appear 
to  have  been  the  first  people  in  Europe 
who  excelled  in  the  art  of  making  artifi- 
cial flowers  ;  but  of  late  years  the  French 
have  been  most  ingenious  in  this  branch 
of  industry.  Ribbons  folded  in  different 
colors  were  originally  employed  for  imi- 
tating flowers,  by  being  attached  to  wire 
stems.  This  imitation  soon  gave  way  to 
that  of  feathers,  which  are  more  delicate 
in  texture,  and  more  capable  of  assuming 


a  variety  of  flower-like  figures.  But  a 
great  difficulty  was  encountered  in  dye- 
ing them  with  due  vivacity.  The  savages 
of  South  America  manufacture  perfect 
feather  flowers,  derived  from  the  bril- 
liant plumage  of  their  birds,  which  close- 
lv  resemble  the  products  of  vegetation. 
The  blossoms  and  leaves  are  admirable, 
while  the  colors  never  fade.  The  Italians 
employ  frequently  the  cocoons  of  the  silk- 
worm for  this  purpose ;  these  take  a 
brilliant  dye,  preserve  their  color,  and 
possess  a  transparent  velvety  appearance, 
suitable  for  petals.  Of  late  years,  the 
French  have  adopted  the  finest  cambric 
for  making  petals,  and  the  taffeta  of  Flo- 
rence for  the  leaves. 

Tissue  paper,  twisted  on  wire,  consti- 
tute the  stem  and  branches.  The  lea*  »s 
are  made  from  muslin,  cambric,  velvet, 
and  gold  and  silver  lama  muslin,  which 
are  stamped  out  with  a  die,  having  the 
form  and  outline  of  the  leaf.  The  flowers 
are  made  from  velvets  and  muslin  stamp- 
ed out  as  the  leaves,  and  tinted  with 
transparent  colors  ;  occasionally  the  fine 
variations  on  the  surface  are  painted  with 
pencil  and  paint. 

The  greater  amount  of  artificial  flowers, 
and  the  richer  kinds,  are  imported  from 
France.  The  manufacture  of  the  com- 
mon kinds  in  this  country  is,  however, 
very  extensive. 

M.  de  Bernardiere  employs  whalebone 
in  very  thin  leaves  for  artificial  flowers  ; 
and  by  bleaching  and  dyeing  them  of  vari- 
ous colors,  he  has  succeeded  in  making 
his  imitations  of  nature  to  be  very  re- 
markable. 

The  coloring  matters  used  in  flower 
dyeing  are  the  following : 

For  red  :  carmine  dissolved  in  a  solu- 
tion of  salt  of  tartar,  or  in  water  of  am- 
monia. 

For  blue :  indigo  dissolved  in  sulphurk 
acid,  diluted  and  neutralized  in  part  by 
Spanish  whitening  or  chalk. 

For  bright  yellow :  a  solution  of  tur- 
meric in  spirit  of  wine.  Cream  of  tartar 
brightens  all  these  colors. 

For  violet :  archil,  and  a  blue  bath. 

For  lilach :  archil. 

Some  petals  are  made  of  velvet,  and  are 
colored  merely  by  the  application  of  the 
finger  dipped  in  the  dye. 

FLUATES,  more  properly  fluorides, 
compounds  of  fluorine  and  the  metals,  as 
fluor  spar,  for  example,  which  consists  of 
fluorine  and  calcium. 

FLUKE  is  also  applied  in  navigation  to 
the  broad  part  of  the  anchor,  which  takes 
hold  of  the  ground. 


FLU] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


179 


FLUOttORIC  ACID.  A  gas  obtained 
by  heating  to  redness  a  mixture  of  dry 
boracic  acid  and  powdered  fluor  spar. 
Its  specific  gravity  is  2*36.  It  is  color- 
less, pungent,  and  produces  a  dense 
white  cloud  when  it  escapes  into  a  moist 
atmosphere;  it  is  resolved  by  the  action 
of  water  into  boracic  and  hydrofluoric 
acids.  It  acts  with  great  energy  upon 
animal  and  vegetable  substances,  and 
chars  them.  It  is  probable  a  compound 
ot  20  parts  of  boron  and  108  of  fluorine, 
or  of  one  atom  of  boron  and  6  atoms  of 
fluorine. 

FLUORIC  ACID.  See  Htdboflttokic 
Acid. 

FLUORINE.  The  hypothetical  base 
of  the  hydrofluoric  acid;  it  has  not  yet 
been  obtained  in  a  separate  state. 

FLUOR  SPAR.  This  is  a  common 
mineral  product,  found  in  great  beauty 
in  Derbyshire;  hence  known  in  this 
country  under  the  name  of  the  Derby- 
shire spar.  It  is  generallv  crystallized  in 
cubes,  but  its  primitive  form  is  an  octa- 
hedron. ^  It  is  of  various  colors,  and  often 
beautifully  banded,  especially  when  in 
nodules,  which  are  much  piized  for  the 
manufacture  of  vases,  and  occasionally 
used  for  beads,  brooch  stones,  and  other 
ornamental  purposes.  It  is  probably  a 
compound  ot  fluorine  and  calcium,  hence 
a.  fluoride  of  calcium.  The  term  Jt nor  is 
derived  from  the  fusibility  of  this  sub- 
stance, on  which  account  it  is  sometimes 
used  as  a  flux  to  promote  the  fusion  of 
certain  refractory  minerals.  It  is  manu- 
factured at  Matlock  and  Derby  into  a  great 
varietv  of  articles.  It  abounds  m  N.  Jersey. 
FLUOSILICIC  ACID.  A  gas  obtain- 
ed by  applying  a  gentle  heat  to  a  mix- 
ture of  one  part  of  powdered  fluor  spar, 
one  of  silica,  and  two  of  sulphuric  acid 
in  a  retort.  It  is  colorless,  pungent, 
fumes  when  it  escapes  into  a  humid  air, 
and  is  rapidly  absorbed  by  water.  Its 
specific  gravity  is  about  3-6  ;  100  cubic 
niches  weighing  nearly  112  grains.  It  is 
decomposed  by  water,  and  forms  silica 
and  hydrofluric  acid.     It  consists  of  8 

Earts  by  weight  of  silicium,  and  18   of 
uoride,  its  equivalent  (upon  the  hydro- 
gen scale)  being  26. 

FLUIDITY  is  that  state  of  a  substance 
in  which  its  constituent  particles  are  so 
slightly  cohesive  that  they  yield  to  the 
smallest  impressions.  The  term  is  usual- 
ly confined  to  express  the  condition  of 
the  nonelastic  fluids  ;  and  hence  it  de- 
notes one  of  the  three  states  in  which 
matter  exists ;  namely,  the  solid,  the 
fluid  or  liquid,  and  the  gaseous.    The 


state  of  fluidity  is  best  defined  as  that  in 
which  bodies  tend  to  form  drops,  as  this 
disposition  does  not  belong  either  to 
bodies  in  a  gaseous  form,  or  to  solid 
bodies  reduced  to  fine  powder.  The  for- 
mation of  drops  arises  from  this,  that  the 
molecules  of  fluid  bodies  adhere  to  each 
other  with  a  certain  force,  at  the  same 
time  that  they  glide  over  one  another 
without  any  sensible  resistance.  It  is  in- 
correct to  say  that  the  molecules  of  bodies 
in  a  state  of  fluidity  offer  no  resistance  to 
separation  ;  for,  on  bringing  a  flat  disc  of 
glass  or  metal  into  contact  with  the  sur- 
face of  a  liquid,  a  very  sensible  degree  of 
force  is  required  to  separate  them.  That 
adhesion  exists  among  the  molecules  of 
fluid  bodies  is  also  proved  by  various 
other  phenomena.  Water  or  mercury 
on  a  flat  plate  of  metal  collects  in  glo- 
bules, and  when  slowly  poured  into  a 
wine  glass  will  remain  heaped  up,  as  it 
were,  above  the  level  of  the  edge. 

Various  hypotheses  have  been  framed 
by  philosophers  to  explain  the  different 
states  in  which  matter  is  found  to  exist. 
Confining  ourselves  to  the  most  general 
views,  we  may  regard  all  bodies  as  "assem- 
blages of  particles  constantly  maintained 
in  equilibrium  between  two  forces,  an 
attractive  force  which  tends  to  unite  the 
particles,  and  a  repulsive  force  which 
tends  to  increase  the  distance  between 
them.  The  solid  state  results  from  the 
preponderance  of  the  attractive  force. 
Conceive  the  repulsive  force  to  receive 
an  augmentation  until  it  becomes  equal 
to,  or  forms  an  equilibrium  with,  the  at- 
tractive force.  When  the  two  forces  are 
thus  balanced,  the  particles  exert  on  each 
other  neither  attraction  nor  repulsion, 
and  the  body  is  in  the  fluid  state.  Last- 
ly, if  the  repulsive  energy  be  still  increas- 
ed, the  particles  will  be  separated  from 
each  other  to  such  distances  that  their 
mutual  attractions  will  cease  altogether 
to  be  sensible,  and  then  the  body  passes 
Into  the  gaseous  state.  Hence  we  may 
pronounce  that  there  is  no  natural  state 
of  body ;  and  that  fluidity,  solidity,  the 
state  of  vapor,  and  the  aeriform  state  are 
only  accidental,  and  determined  by  the 
temperature  of  the  medium  in  which  the 
body  is  placed. 

FLUX.  A  substance  which  is  mixed 
with  metallic  ores,  or  other  bodies,  to 
promote  their  fusion,  just  as  an  alkali  is 
mixed  with  silica  to  form  a  glass.  From 
the  property  which  the  borates  possess 
of  fusing  metalic  oxides,  they  are  used 
by  braziers,  tinmen,  &c.  It  Is  this  salt 
which  is   chiefly  used  in  the  fusion  of 


180 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[foo 


minerals  before  the  blow-pipe.  White 
flux,  is  made  by  mixing  2  parts  of  nitre 
and  1  of  cream  tartar,  and  deflagrating 
them  in  a  crucible ;  it  is  carbonate  of 
potash.  Black  flux  is  obtained  when 
equal  parts  of  the  same  ingredients  are 
used :  beside  the  carbonate  of  potash,  it 
contains  charcoal:  this  last  aids  in  the 
reduction  of  metallic  oxides.  Limestone, 
fluor  spar,  borax,  and  several  earths  and 
metallic  oxides  are  used  as  fluxes  in 
metallurgy. 

FLY.  In  mechanics,  an  appendage 
given  to  machines  for  the  purpose  of  re- 
gulating and  equalizing  the  motion,  as  in 
the  windlass,  jack,  pile-engine,  &c. ;  and 
sometimes  for  collecting  force  in  order  to 
produce  a  very  great  instantaneous  im- 
pression, as  in  the  coining  press.  Gene- 
rally it  is  formed  of  a  heavy  disc  or  hoop 
at  right  angles  to  the  axis  ;  sometimes  of 
heavy  knobs  at  the  extremities  of  a  bar 
having  the  same  position.  The  fly  is  of 
great  use  in  all  cases  where  the  power,  or 
the  resistance,  acts  unequally  in  the  dif- 
ferent parts  of  a  revolution. 

FLYING  BUTTRESS.  In  Gothic  ar- 
chitecture, a  buttress  in  the  form  of  an 
arch,  springing  from  a  solid  mass  of  ma- 
sonry, and  abutting  against  the  spring- 
ing of  another  arch  which  rises  from  the 
upper  points  of  abutment  of  the  first. 
It  is  seen  in  most  ancient  cathedrals,  and 
its  office  is  to  act  as  a  counterpoise  against 
the  vaulting  of  the  nave.  If  flying  but- 
tresses were  built  solid  from  the  ground, 
it  is  obvious  that  they  would  interfere 
with  the  vista  along  the  aisles  of  the 
church ;  hence  the  project  of  continuing 
a  resistance  by  means  of  arches.  Their 
stability  depends  on  the  resistance  afford- 
ed by  the  weight  of  the  vertical  buttress 
from  whence  they  sprinsr. 

FLY  POWDEE.  An  imperfect  oxide 
of  arsenic,  formed  by  the  exposure  of  na- 
tive arsenic  to  the  air ;  when  mixed  with 
sugar  and  water  it  is  used  to  kill  flies. 

FOIL.  A  term  generally  applied  to  a 
varnished  metal.  Common  foil  is  thus 
made :  a  copper  plate  covered  with  a 
thin  layer  of  silver  is  rolled  out  into 
sheets  under  the  flatting  mill.  The  sil- 
ver surface  is  then  highly  polished,  or 
covered  with  a  colorless  varnish.  The 
colored  foils  are  similarly  prepared  with 
oolored  varnishes. 

FOOD.  All  substances  susceptible  of 
digestion  and  assimilation  may  come 
under  the  denomination  of  food  ;  but  the 
proximate  principles  of  organic  bodies  on 
which  their  mitritive  powers  depend  are 
comparatively  few.    Hence,  although,  the 


j  articles  employed  in  different  countries 

|  for  the  support  of  animal  life  are  almost 

1  infinitely  various,  their  sustaining  powers 

may  be  referred  to  certain   substances 

capable  of  being  separated  and  identified 

by  chemical  analysis  and  tests.    Among 

the  proximate  elements  of  vegetable  food 

gluten  and  its  modifications,  starch,  gum, 

sugar,   oil,   wax,   and    lignin  or  woody 

fibre,  are  by  far  the  most  important ;  and 

among  those  of  animal  food  albumen, 

gelatin,  and  their  modifications,  together 

j  with  fats  and  oils,  which  are  common  to 

both  kingdoms  of  nature. 

To  illustrate  the  actual  simplicity  of  our 
food  as  compared  with  its  apparent  multi- 
fariousness and  complexity,  it  may  suffice 
to  state,  that  wheat  and  almost  "all  the 
esculent  grains  consist  principally  of 
starch  and  gluten;  that  the  same  ingre- 
dients are  found  in  many  fruits  and  roots ; 
that  sugar,  gum  or  a  relation  of  gum  which 
is  called  vegetable  jelly,  together  with 
minute  traces  of  aromatic  principles  which 
give  flavor,  and  more  or  less  abundance 
of  water,  and  of  vegetable  acids,  are  the 
chief  component  parts  of  apples,  pears, 
peaches,  currants,  gooseberries,  and  all 
analogous  tribes  of  fruits ;  a  very  few 
also  contain  oil.  Then,  as  regards  animal 
food,  the  muscular  fibres  of  various  ani- 
mals closely  resemble  each  other  in  com- 
position and  nutritive  power ;  in  some 
cases  texture  merely,  and  in  others  mi- 
nute additions  of  foreign  matters,  confer 
upon  them  their  relative  digestibilities, 
and  their  different  aspects  and  flavors; 
albumen  or  fibrine,  and  gelatin,  small 
proportions  of  saline  bodies,  and  a  large 
quantity  of  water  are  found  in  them  all. 

It  often  happens  that  the  truly  nutri- 
tious part  of  food  is  so  combined  with  or 
protected  by  indigestible  matters,  as  to 
escape  the  solvent  powers  of  the  stomach, 
unless  previously  prepared  and  modified 
by  various  chemical  and  mechanical 
agents.  Indurated  woody  fibre,  tor  in- 
stance, or  lignin,  as  chemists  call  it,  will 
often  resist  the  joint  action  of  the  stomach 
and  bowels,  and  pass  through  the  ali- 
mentary canal  with  scarcely  any  altera- 
tion. The  husks  of  many  seeds  and 
fruits  are  composed  almost  exclusively  of 
this  material.  This  is  the  case  with  the 
kernels  of  the  apple,  pear,  &c;  the  seeds 
of  the  currant,  gooseberry,  melon,  and  so 
on ;  the  skin  or  husk  of  peas,  beans,  &c, 
and  of  wheat,  barley,  and  oats ;  so  that 
unless  the  woody  part  is  either  broken 
down  by  the  teeth  or  previously  removed, 
the  food  which  it  envelops  is  protected 
from  the  solvent  action  of  the  secretions 


FOo] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


181 


of  the  stomach.  This  is  in  some  respects 
a  wise  and  curious  provision  in  nature ; 
for  birds  in  this  way  become  the  carriers 
of  seeds,  which  pass  through  them  not 
only  undigested,  but  even  retaining  their 
vegetative  powers ;  and  in  this  way  un- 
inhabited and  sterile  portions  of  the  globe 
may  gradually  become  clothed  with  verd- 
ure, and  shrubs,  and  trees.  Bones  are 
highly  nutritive  ;  but  unless  broken  into 
very  small  fragments  by  the  masticatory 
powers  of  the  animals  which  eat  them, 
they  too  would  elude  digestion.  In  refer- 
ence, however,  to  the  food  of  man,  much 
of  its  digestibility  and  nutritious  power 
is  referable  to  the  important  chemical 
operations  preparatory  to  its  use  which  are 
carried  on  in  the  kitchen ;  in  other  words, 
cookery  is  essentially  a  chemical  art ;  and 
substances  totally  unfit,  in  their  raw  state, 
for  reception  into  the  stomach,  are  ren- 
dered palatable,  digestible,  and  nutritious 
by  the  skill  of  the  cook.  And  here  salt, 
and  a  variety  of  condiments,  as  they  are 
called,  and  which  are  aromatic  and  stimu- 
lant substances,  chiefly  of  vegetable  ori- 
gin, play  an  important  part ;  nor  must 
the  mere  effect  of  heat  be  overlooked,  for 
it  is  most  important.  Meat,  by  boiling 
and  roasting,  is  not  only  softened  in  its 
fibre,  but  new  substances  are  generated 
in  it.  Among  these  a  peculiar  extractive 
matter,  and  osmazone,  or  the  principle 
which  gives  an  agreeable  flavor  and  odor 
to  dressed  meat,  are  especially  recognized. 
Nor  are  the  changes  which  vegetables 
suffer  under  the  influence  of  heat  less 
obvious. 

There  is  another  important  point  in  the 
history  of  our  food,  namely,  its  ultimate 
composition.  We  have  spoken  of  starch, 
sugar,  gum,  albumen,  and  other  substan- 
ces as  the  proximate  principles  upon  which 
we  live  ;  but  what  is  the  ultimate  consti- 
tution of  these  secondary  products,  what 
are  their  true  elements?  It  is  curious 
that  four  elements  only  are  principally  con- 
cerned in  the  production  of  our  food. 
These  are,  carbon,  hydrogen,  oxygen, 
and  nitrogen.  Among  vegetable  sub- 
stances gluten  (including  vegetable  albu- 
men) is  the  only  one  which  abounds  in 
nitrogen;  gum,  sugar,  starch,  and  the 
rest  are  constituted  of  carbon,  hydrogen, 
and  oxygen  only  ;  and  what  is  very  re- 
markable is,  that  in  all  these  important 
principles,  and  also  in  lignin,  the  oxygen 
and  hydrogen  bear  to  each  other  the 
same  relative  proportions  as  in  water,  so 
that  they  may  be  figuratively,  perhaps 
truly,  described  as  compounds  of  charcoal 
and  water.    Now  there  are  two  very  curi- 


ous points  in  reference  to  that  part  of  the 
chemical  history  of  our  food  which  has 
been  adverted  to;  the  one  is,  that  no 
animal  can  subsist  for  any  length  of  time 
upon  food  which  is  destitute  of  nitrogen ; 
and  the  other,  that  a  certain  mixture  of 
different  kinds  of  food  is  absolutely  es- 
sential. An  animal  fed  exclusi/vely  on 
starch,  or  sugar,  or  albumen,  or  jelly, 
soon  begins  to  suffer  in  health ;  peculiar 
diseases" make  their  appearance,  and  his 
existence  is  painful  and  brief;  but  mix 
these  together  and  occasionally  modify 
their  proportions,  and  he  then  thrives  and 
fattens.  Magendie's  experiments  on  this 
subject,  together  with  those  of  Tiedemann 
and  Gmelin,  well  illustrate  this  fact.  Thus, 
geese  fed  upon  gum  died  on  the  16th  day, 
those  fed  upon  starch  on  the  24th,  and 
those  fed  on  the  boiled  white  of  egg  on 
the  46th;  in  all  these  cases  they  dwin- 
dled away  and  died  as  if  from  starva- 
tion. 

Habit,  as  is  well  known,  will  do  much 
in  accustoming  the  stomach  to  particular 
descriptions  of  food  ;  many  persons  live 
exclusively,  or  almost  so,  on  vegetable, 
others  on  animal  matters,  and  particular 
kinds  of  diet  are  forced  on  the  inhabi- 
tants of  many  regions  of  the  globe;  but, 
as  far  as  we  are  concerned,  a  due  mixture 
of  vegetable  and  animal  matter  is  not 
only  most  palatable,  but  most  conducive 
to  health.  The  variety  in  our  teeth  and 
the  structure  of  the  alimentary  canal, 
point  out  a  mixed  food  as  the  most  ap- 
propriate. The  shortness  of  the  intesti- 
nal canal  shows  that  man  was  not  intend- 
ed to  live  solely  on  vegetable  diet. 

Nothing  is  fit  for  food  which  has  not 
already  undergone  organization ;  and  wa- 
ter, though  an  essential  part  of  the  food 
of  all  annuals,  is  obviously  not  in  itself 
nutritious,  though  it  performs  the  ex- 
tremely important  function  of  dissolving 
nutritive  matter,  so  as  to  render  it  con- 
veyable  by  the  lacteals  and  other  absorb- 
ents into  the  blood.  No  compound  then 
of  nitrogen,  hydrogen,  carbon,  and  oxy- 
gen, which  can  be  formed  artificially,  can 
constitute  food.  Air,  water,  and  char- 
coal, though  involving  the  elements  of  our 
nutriment,  are  themselves  unfit  for  our 
support ;  and  it  is  only  by  passing  through 
the  hidden  processes  which  are  carried 
on  in  the  vessels  of  living  things,  that 
they  are  so  recombined  and  modified  as  to 
be  rendered  capable  of  supporting  animal 
life.  It  is  the  vegetable  world  which 
commences  this  wonderful  operation. 
Plants  absorb  their  nutriment  from  the 
air  and  from  the  soil ;  they  assimilate  in- 


182 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[FOO 


inorganic  as  well  as  organic  matter ;  they 
become  the  food  of  the  graminivorous 
tribes,  and  from  these  man  derives  the 
great  bulk  of  his  animal  food.  Animals 
cannot  create  food ;  they  cannot  form  any 
one  of  these  proximate  principles  we 
have  mentioned ;  this  is  the  office  of  the 
plant.  The  plant  is  a  creating  being,  the 
animal  only  assimilates  what  the  plant 
had  formed. 

In  speaking  of  the  composition  of  food, 
that  ot  milk,  the  most  important  of  all 
food,  must  not  be  forgotten ;  in  it  nature 
has  wonderfully  provided  a  mixture 
which,  though  secreted  by  an  animal, 
partakes  also  of  the  nature  of  vegetable 
rood,  and  it  presents  a  perfect  analogy  to 
that  combination  of  vegetable  and  animal 
matter  which  has  been  mentioned  as  most 
congenial  to  the  palate  and  stomach. 
The  albumen  or  curd  of  milk  is  a  highly 
elaborated  animal  principle,  abounding 
in  nitrogen,  yet,  from  its  attenuated  and 
soluble  state,  easy  of  digestion.  A  second 
principle  of  milk  is  what  is  termed  sugar 
of  muk:  in  composition  and  properties 
it  resembles  a  vegetable  product,  and  is 
intermediate  between  gum  and  sugar. 
The  third  component  of  milk  is  butter, 
partaking  of  the  nature  of  vegetable  oil 
and  animal  fat;  there  are  certain  saline 
and  acid  substances  in  small  proportion: 
and  all  these  matters  are  either  dissolved 
or  suspended  in  a  large  relative  propor- 
tion ot  water. 

I.  Table  showing  the  average  quantity  of 
nutritive  matter  in  1000  parts  of  seve- 
ral varieties  of  ajvimal  and  vegetable 
food. 


Blood 215 

Veal  250 

Pork 240 

Chicken 270 

Haddock 180 

Bones 510 

White  of  egg 140 

Bice  880 

Bye 792 

Potatoes 260 

Turnips 42 

Beetroot  148 

Pears   160 

Gooseberries 190 

Plums 290 

Peaches   200 

Melon 80 

Tamarind 340 

Morels 896 

The  above  table  represents  the  relative 
proportions  of  solid  digestible  matter 
contained  in  1000  parts  of  the  different 
articles  of  food  which  are  enumerated. 
When  blood,  for  instance,  is  evaporated 
to  dryness,  at  a  temperature  not  exceed- 


Beef 260 

Mutton  290 

Brain 200 

Cod 210 

Sole 210 

Milk 72 

Wheat    950 

Barley 920 

Oats 742 

Carrots  98 

Cabbage 73 

Strawberries 100 

Apples 170 

Cherries 250 

Apricots 260 

Grapes  270 

Cucumber  25 

Almonds 650 


ing  212°,  the  residue  amounts  to  215  parts 
in  1000,  and  may  be  regarded  as  almost 
entirely  composed  of  digestible  matters ; 
it  consists  of  albumen  and  coloring  mat- 
ter, with  small  proportions  of  saline  sub- 
stances. The  different  kinds  of  meat 
were  dried  in  the  same  way.  The  loss 
of  weight  during  their  desiccation  is  al- 
most wholly  referable  to  water ;  and  the 
dry  residue  composed  of  albumen  or 
fibrine,  with  some  gelatine,  and  perhaps 
traces  of  fat  and  of  saline  matters,  repre- 
sents the  true  nutritive  value.  Upon  an 
average,  therefore,  the  nutritive  matter 
in  a  pound  of  meat  is  not  more  than  four 
ounces.  This,  however,  only  applies  to 
raw  meat ;  for  when  dressed  a  consider- 
able portion  of  its  constituent  water  is 
often  dissipated.  The  nutritive  matter 
of  wheat  is  chiefly  starch  and  gluten,  and 
in  this  species  of  grain  the  gluten  is  in 
much  greater  relative  proportion  to  the 
starch  than  in  barley,  oats,  or  rye.  Iii 
rice  there  is  little  else  than  starch.  There 
can  be  little  doubt  that  the  great  value  of 
wheat  as  an  article  of  food  depends  upon 
this  excess  of  gluten,  which  is  a  nitro- 
genous substance,  and  has  not  inaptly 
been  termed  the  vegeto-animal  princi- 
ple. In  the  esculent  roots,  such  as  car- 
rots, &c.j  but  especially  turnips,  sugar  is 
the  leading  nutritive  matter ;  and  the 
common  fruits  contain  sugar,  gum,  albu- 
minous matter,  and  acids,  together  with 
a  highly  attenuated  form  of  woody  fibre, 
or  lignm,  which,  in  that  state,  is  probably 
digestible. 

The  following  table  shows  the  ultimate 
composition  of  those  proximate  princi- 
ples which  have  been  above  adverted 
to  as  constituting  the  nutritive  part  of 
food. 

II.  Table  showing  the  ultimate  elementary 
composition  in  1000  parts  of  the  following 
proximate  principles  in  animal  and 
vegetable  food. 


£ 

i 

S 

j 

1 

© 

s 

o 

n 

Albumen  

516 

76 

258 

150 

Gelatin  

483 

80 

276 

161 

Fat 

780 
609 

122 
73 

98 
116 

Curd  of  milk... 

208 

Sugar  of  milk.. 

454 

61 

485 

Gluten 

557 

78 

220 

145 

Starch 

438 

62 

500 

Gum 

419 
444 

68 
62 

513 
494 

Sugar 

Lignin 

500 

56 

444 

CYCLOPEDIA    OF   THE   USEFUL    ARTS. 


183 


Tables  like  the  above  have  been  used 
to  point  out  the  nutritive  values  of  food  ; 
those  which  contain  the  greatest  amount  of 
nitrogen  being  esteemed  the  most  nutri- 
tious ;  this  view  must  not,  however,  be 
too  hastily  adopted.  If  the  nitrogen  exist 
in  the  form  of  albumen,  gluten,  fibrin,  or 
casein,  any  of  the  forms  of  what  Mulder 
has  termed  Protein,  the  composition  of 
which  is,  carbon  54-37,  hydrogen  7*12, 
nitrogen  15*93,  and  oxygen  22-58,  in  100 
parts,  it  is  undoubtedly  true.  But  many 
substances  contain  nitrogen  in  other 
forms,  as  the  mushroom  tribe ;  in  these 
it  exists  as  ammonia,  which  does  not  in 
any  way  contribute  to  the  nutrition  of  an 
animal.  Such  substances  therefore  have 
not  a  nutritive  value  at  all  equal  to  what 
the  percentage  of  nitrogen  in  them  would 
indicate. 

The  uses  of  these  proximate  principles 
to  the  animal  frame  are  different.  The 
substances  containing  nitrogen  go  to  form 
the  solid  parts  of  the  blood  and  muscle 
of  the  animal ;  the  starch,  gum,  and  sugar 
assist  in  respiration  and  in  producing 
animal  heat;  the  oils  and  fat  serve  the 
same  end,  and  are  occasionally  stored  up 
as  fat  in  the  animal  frame  to  meet  the 
wants  of  the  system  when  it  may  require 
it. 

FORCE,  in  mechanics,  denotes  that 
combination  of  matter  and  motion  which 
produces  a  change  in  the  state  or  position 
of  a  body.  According  to  this  definition, 
the  muscular  power  of  animals,  as  like- 
wise pressure,  impact,  gravity,  &c,  are 
considered  as  effects  of  motion  in  other 
bodies  ;  it  being  evident,  from  daily  ex- 
perience, that  bodies  exposed  to  any  free 
action  have  force  imparted  to  them,  or 
are  themselves  thereby  imbued  with 
power.  All  forces,  however  various,  are 
measured  by  the  effects  which  they  pro- 
duce in  like  circumstances,  whether  the 
effect  be  creating,  accelerating,  retarding, 
or  deflecting  motions. 

When  we  say  that  a  force  is  represent- 
ed by  a  right  line,  A  B,  it  is  to  be  under- 
stood that  it  would  cause  a  material  body, 
situated  at  A,  to  run  over  the  line  A  B, 
which  is  called  the  direction  of  the  force, 
so  as  to  afrive  at  B  at  the  end  of  a  given 
time,  while  another  force  would  cause  the 
same  body  to  have  moved  a  greater  or 
less  distance  from  A  in  the  same  time. 

The  force  of  a  body  in  motion  is  a 
power  residing  in  that  body,  so  long  as  it 
continues  its  motion  :  by  means  of  which, 
it  is  able  to  move  other  bodies  lying  in 
its  way,  or  to  lessen,  destroy,  or  overcome 
the  force  of  any  other  moving  body, 


which  meets  it  in  an  opposite  direction ; 
or,  to  surmount  the  largest  dead  pressure 
or  resistance. 

Force  is  quantity  by  velocity,  before  or 
after  impact ;  and  if  quantity  is  increased, 
velocity  is  diminished.  Nature  and  art 
is  a  display  of  the  transfer  and  reception 
of  force,  ad  infinitum,  and  what  is  lost  by 
one  body,  is  gained  by  other  bodies,  by 
these  transferred  again,  and  Fometimes 
collected  or  concentrated,  and  at  othei 
times  scattered  and  diffused.  To  trace 
the  sources  and  distribution,  is  to  analyze 
nature ;  but  it  is  the  most  general  of  all 
laws,  that  wherever  there  is  force,  there 
is  some  matter,  in  some  fit  motion  ;  and 
wherever  there  is  matter  in  motion,  there 
is  resulting  force. 

Of  course,  there  are  no  innate,  or  mir- 
aculous forces — no  attraction — no  repul- 
sion— no  elastic  force — no  vital  force — all 
are  derived  from  previous  motions  in 
other  bodies,  and  the  phenomena  depend 
on  the  quantities  of  the  agents  and  pa- 
tients, on  the  direction  of  their  velocity, 
and  on  various  reactions. 

Composition  of  forces  takes  place  when 
two  or  more  forces,  differently  directed, 
act  upon  the  same  body  at  the  same  time. 
As  the  body  then  cannot  obey  them  all, 
it  will  move  in  a  direction  somewhere 
between  their  line.  This  is  called  the 
composition  and  resolution  of  forces  or  of 
motion.  But,  if  the  bodv  be  impelled  by 
equal  force,  acting  at  right  angles  to  each 
other,  it  will  move  in  the  diagonal  of  a 
square,  and  instances  in  nature,  of  mo- 
tion produced  by  several  powers  acting 
at  the  same  time,  are  innumerable. 

All  machines  are  impelled  either  by  the 
exertion  of  animal  force,  or  by  the  appli- 
cation of  other  powers  of  nature.  The 
latter  comprise  the  elements  of  water, 
air,  and  fire.  The  former  is  more  com- 
mon, yet  so  variable  as  hardly  to  admit 
of  calculation.  It  is  derived  from  the 
muscular  lever  of  the  animal  acting 
against  the  ground,  and  the  power  of  the 
muscles  to  act  is  derived  from  the  gas 
fixed  by  respiration.  It  depends  not  only 
on  the  vigor  of  the  individual,  but  on  the 
different  strength  of  the  particular 
muscles  employed.  Every  animal  exer- 
tion is  attended  by  fatigue  of  the  muscles ; 
it  soon  relaxes,  and  would  speedily  pro- 
duce exhaustion.  The  most  profitable 
mode  of  applying  the  labor  of  animals  is 
to  vary  their  "muscular  action,  and  revive 
its  tone  by  short  and  frequent  intervals 
of  repose.*  The  ordinary  method  of  com- 
puting the  effects  of  human  labor  is,  from 
the  weight  which  it  is  capable  of  elevat- 


184 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[for 


ing  to  a  certain  height,  in  a  given  time, 
the  product  of  these  three  numbers  ex- 
pressing the  absolute  quantity  of  perfor- 
mance. This  was  reckoned  by  Bernoulli 
and  Desaguliers,  at  2,000,000  lbs.  avoir- 
dupois, which  a  man  could  raise  one  foot 
in  a  day.  But,  our  civil  engineers  have 
gone  much  further,  and  are  accustomed, 
m  their  calculations,  to  assume  that  a 
laborer  will  lift  10  lbs.  to  a  height  of  10 
feet  every  second,  and  is  able  to  continue 
such  exertion  for  10  hours  each  day,  thus 
accumulating  the  performance  of  3,600,- 
000  one  foot. 

Coulomb  has  furnished  the  most  accu- 
rate and  varied  observations  on  the  mea- 
sure of  human  labor.  A  man  will  climb 
a  stair,  of  from  70  to  100  feet  high,  at  the 
rate  of  45  feet  in  a  minute.  Beckoning 
his  weight  at  155  lbs.,  the  animal  exer- 
tion for  one  minute  is  6975  lbs.,  and  would 
amount  to  4,185,000,  if  continued  for  10 
hours.  A  person  may  clamber  up  a  rock 
500  ft.  high,  by  a  ladder-stair,  in  20 
minutes,  and,  consequently,  at  the  rate 
of  25  feet  each  minute ;  his  efforts  are 
thus  already  impaired,  and  the  perfor- 
mance reaches  only  3875  in  a  minute. 
But,  under  the  incumbrance  of  a  load, 
the  quantity  of  action  is  still  more  re- 
markably diminished.  A  porter,  weigh- 
ing 140  lbs.,  was  found  willing  to  climb 
a  stair,  40  ft.  high,  266  times  in  a  day ; 
but  he  could  carry  up  only  66  loads  of 
firewood,  each  of  them  163  lbs.  weight. 
In  the  former  case,  his  daily  performance 
was  very  nearly  1,500,000;  while,  in  the 
latter,  it  amounted  only  to  808,000. 

The  quantity  of  permanent  effect  was 
hence  only  about  700,000,  or  scarcely  half 
the  labor  exerted  in  mere  climbing.  In 
the  driving  of  piles,  a  load  of  42  lbs., 
called  the  ram,  is  drawn  up  H  ft.  high 
20  times  in  a  minute  ;  but  the  work  has 
been  considered  so  fatiguing,  as  to  endure 
only  three  hours  a  day.  This  gives  about 
530,000  for  the  daily  performance.  Near- 
ly the  same  result  is  obtained  by  comput- 
ing the  quantity  of  water,  which,  by 
means  of  a  double  bucket,  a  man  drew  up 
from  a  well.  He  lifted  36  lbs.  120  times 
in  a  day,  from  a  depth  of  120  ft.,  the  total 
effect  being  518,400.  A  skilful  laborer, 
working  in  a  field  with  a  large  hoe, 
creates  an  effect  equal  to  728,000.  When 
the  agency  of  a  winch  is  employed  in 
turning  a  machine,  the  performance  is 
still  greater,  amounting  to  845,000.  In 
all  these  instances,  a  certain  weight  is 
heaved  up,  but  a  much  smaller  effort  is 
sufficient  to  transport  a  load  horizontally. 

A  man  could,  in  the  space  of  a  day, 


I  scarcely  reach  an  altitude  of  two  miles. 
;  by  climbing  up  a  stair,  though  he  will 
!  easily  walk  over  30  miles,  on  a  smooth 
I  and  level  road.    But  he  would,  in  the 
j  same  time,  carry  130  lbs.  only  to  the 
1  fourth    part    of   that    distance,    or   71 
miles.    Assuming  his  own  weight  to  be 
140  lbs.,  the  quantity  of  horizontal  action 
would  amount  to  42,768,000,  or  28  times 
the  vertical  performance ;  but  the  share 
of  it,  in  conveying  the  load,  is  20,961,780, 
or  about  30  times  what  was  spent  in  its 
elevation.    The  greatest  advantage  is  ob- 
tained by  reducing  the  burthen  to  102  lbs., 
the  length  of  journey  being  augmented 
in  a  higher  ratio. 

According  to  some  experiments  of  th« 
late  Mr.  Buchanan,  the  exertions  of  a 
man  in  working  a  pump,  in  turning  a 
winch,  in  ringing  a  bell,  and  in  rowing  a 
boat,  are  as  the  numbers  100,  167,  227, 
and  248. 

A  man's  force,  in  fact,  is  such,  that  he 
can  raise  10  lbs.  10  ft.  in  a  second,  for  10 
hours  in  a  day,  or  100  lbs.,  or  10  imperial 
gallons,  1  ft.  per  second,  or  in  10  hours, 
(36,000  seconds)  3,600,000  lbs.  one  ft.,  or 
360,000  gallons  one  ft. 

The  labor  of  a  harse  in  a  day  is  com- 
monly reckoned  equal  to  that  of  five 
men;  but  then  he  works  only  eight 
hours,  while  a  man  easily  continues  nis 
exertions  for  ten  hours.*  Horses,  like- 
wise, display  much  greater  force  in  carry- 
ing than  in  pulling ;  and  yet  an  active 
walker  will  beat  them  on  along  journey. 
Their  power  of  drawing  seldom  exceeds 
144  lbs.,  but  they  are  capable  of  carrying 
more  than  six  times  as  much  weight. 
With  regard  to  the  ordinary  power  of 
draught,  the  formula  (12 — w)2,  where  i 
denotes  the  velocity  in  miles  an  hour, 
will  perhaps  be  found  sufficiently  neai 
the  truth.  Thus,  a  horse  beginning  hit 
pull  with  the  force  of  144  lbs.,  would  drav» 
100  lbs.  at  a  walk  of  two  miles  an  hoar, 
but  only  64  lbs.  when  advancing  at 
double  that  rate,  and  not  more  than  38 
lbs.  if  he  quickened  his  pace  to  six  milea 
an  hour.  His  greatest  performanca 
would  hence  be  made  with  the  velocity 
of  4  miles  an  hour.  The  accumulated 
effort  in  a  minute  will  then  amount  to 
22,528.  The  measure  generally  adopted 
for  computing  the  power  of  steam-en- 

fines  is  much  higher,  the  labor  of  a  horse 
eing  reckoned  sufficient  to  raise,  every 
minute,  to  the  olevation  of  one  ft.?  the 
weight  of  32,000  lbs.  Wheel-carnages 
enable  horses,  on  level  roads,  to  draw,  at 
an  average,  loads  about  15  times  greater 
than  the  power  exerted. 


FOu] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


185 


FORCER.  In  Mechanics,  a  solid  pis- 
ton applied  to  pumps  for  the  purpose  of 
producing  a  constant  stream,  or  of  rais- 
ing water  to  a  greater  height  than  it  can 
be  raised  by  the  pressure  of  the  atmo- 
sphere.    See  Pump. 

FORGE.  The  workshop  in  which 
iron  is  hammered  and  shaped  by  the  aid 
of  heat.  The  term  is  generally  applied 
to  the  places  in  which  these  operations 
are  carried  on  upon  the  comparatively 
small  scale ;  the  great  workshops  in 
which  iron  is  made  malleable  for  general 
purposes  being  called  a  shingling  mill. 
A  common  forge  consists  of  the  hearth  or 
fireplace,  which  is  merely  a  cavity  in 
masonry  or  brickwork  well  lined  with 
fine  clay  or  brick,  upon  which  the  ignited 
fuel  is  placed,  and  upon  the  back  or  side 
of  which  a  powerful  blast  of  air  is  driven 
in  through  the  nozzle  of  a  double-blasted 
bellows,  which,  in  a  common  forge,  is 
generally  worked  by  a  hand  lever.  Forges 
are  sometimes  constructed  so  as  to  be 
portable,  when  the  bellows  is  most  con- 
veniently placed  under  the  hearth :  these 
are  used  in  ships,  and  for  various  jobs 
on  railways,  &c. 

FORMIC  ACID.  A  sour  liquor  which 
ants  eject  when  irritated,  and  which  was 
formerly  obtained  by  bruising  the  in- 
sects and  distilling  them,  mixed  with 
water ;  a  peculiar  volatile  acid  passed 
over.  It  has  been  ascertained  by  Dobe- 
reiner,  that  an  analogous  acid  may  be  ar- 
tificially obtained  by  distilling,  from  a 
capacious  retort,  a  mixture  of  2  parts  of 
tartaric  acid,  3  of  peroxide  of  manganese, 
and  3  of  sulphuric  acid  diluted  with  5 
of  water.  The  tartaric  acid  acquires  oxy- 
gen from  the  oxide  of  manganese,  and  is 
resolved  into  water,  carbonic  acid,  and 
formic  acid.  From  the  analysis  by  Ber- 
zelius,  of  formiate  of  lead,  it  appears  that 
formic  acid  is  a  compound  of  2  atoms  of 
carbon,  3  of  oxygen,  and  1  of  hydrogen ; 
or  of  2  atoms  of  carbonic  oxide,  and  1  of 
water. 

This  acid  decomposes  the  salts  of  a  few 
Yuetals.  Silver  is  readily  thrown  out  in 
the  state  of  bright  metal  on  glass  sur- 
faces, by  means  of  formic  acid. 

FOUNDING,  of  Ikon.  The  opera- 
tions of  an  iron  foundry  consist  in  re- 
melting  the  pig-iron  of  the  blast  furnaces, 
and  giving  it  an  endless  variety  of  forms, 
by  casting  it  in  moulds  of  different  kinds, 
prepared  in  appropriate  manners.  Coke 
is  the  only  kind  ot  fuel  employed  to  effect 
the  fusion  of  the  cast-iron. 

The  essential  parts  of  a  well-mounted 
iron  foundry  are, 


Magazines  for  pig-irons  of  different 
qualities,  which  are  to  be  mixed  in  cer- 
tain proportions,  for  producing  castings 
of  peculiar  qualities;  as  also  for  coal, 
coke,  sands,  clay,  powdered  charcoal,  and 
cow-hair  for  giving  tenacity  to  the  loam 
mouldings. 

One  or  more  coke  ovens. 

A  workshop  for  preparing  the  pattern 
and  materials  of  the  moulds.  It  should 
contain  small  edge  millstones  for  grind- 
ing and  mixing  the  loam,  and  another 
mill  for  grinding  coal  and  charcoal. 

A  vast  area,  called  properly  the  foun- 
dry, in  which  the  moulds  are  made  and 
filled  with  the  melted  metal.  These 
moulds  are  in  general  very  heavy,  con- 
sisting .  f  two  parts  at  least,  which  mus*-- 
be  separated,  turned  upside  down  seve- 
ral times,  and  replaced  very  exactly  upon 
one  another.  The  casting  is  generally 
effected  by  means  of  large  ladles  or  pots, 
in  which  the  melted  iron  is  transported 
from  the  cupola,  where  it  is  fused. 
Hence,  the  foundry  ought  to  be  provided 
with  cranes,  having  jibs  movable  in  every 
direction. 

A  stove  in  which  such  moulds  may  be 
readily  introduced  as  require  to  be  en- 
tirely deprived  of  humidity,  and  where 
a  strong  heat  may  be  uniformly  main- 
tained. 

Both  blast  and  air  furnaces,  capable 
of  melting  speedily  the  quantity  of  cast- 
iron  to  be  employed  each  day. 

A  blowing  machine  to  urge  the  fusion 
in  the  furnaces. 

The  mode  of  casting  metal  pipes  will 
serve  to  illustrate  many  different  varie- 
ties of  iron-founding.  There  is  formed, 
in  the  first  place,  a  core  or  central  pat- 
tern of  cast-iron,  with  alternate  grooves 
and  ridges  extending  from  end  to  end. 
Round  this  is  wrapped  a  covering  of  hay 
or  straw  rope,  and  this  rope  is  plastered 
with  a  layer  of  wet  loam  or  clay,  worked 
until  the  exterior  surface  becomes  cylin- 
drical, and  corresponding  in  diameter 
with  the  internal  dimensions  of  the  pipe 
to  be  made.  From  this  mode  of  forma- 
tion it  follows  that  there  are  hollow  chan- 
nels or  gutters  beneath  the  straw-rope, 
and  these  serve  for  the  exit  of  heated  air 
in  the  subsequent  processes.  The  core, 
when  formed,  is  sprinkled  with  powder- 
ed charcoal,  and  placed  in  a  heated  oven 
to  harden.  Meanwhile,  the  mould  for 
giving  the  external  form  of  the  pipe  is 
being  prepared.  A  model,  or  pattern,  is 
made,  corresponding  exactly  with  the 
exterior  of  the  pipe  to  be  made,  and  with 
this  pattern  a  mould,  or  cavity,  is  form 


186 


CYCLOPEDIA   OF   THE    USEFUL   ARTS. 


[fou 


ed  in  a  smooth  oed  of  sand,  in  two  halves. 
Then,  when  the  core  is  placed  and  sup- 
ported concentrically  in  this  mould,  there 
is  a  cylindrical  space  between  the  two, 
equal  to  the  thickness  of  the  intended 
pipe.  Holes  for  the  admission  of  the 
melted  metal,  and  others  for  the  exit  of 
the  heated  air,  are  provided,  and  the 
metal  is  poured  in  from  the  ladles  or 
vessels  before  alluded  to.  It  will  be 
plain,  on  a  little  consideration,  that  the 
exterior  of  the  core  must  give  the  in- 
terior form  to  the  pipe,  while  the  interior 
of  the  mould  must  give  the  exterior  form 
to  the  pipe. 

In  casting  pipes  of  large  diameter,  the 
core  and  mould  are  built  up  vertically  in 
a  pit  as  deep  as  the  pipes  are  long ;  and 
matters  are  so  arranged  that  the  liquid 
metal  is  poured  in  at  one  end.  In  cast- 
ing large  cylinders  for  steam-engines 
and  other  purposes,  the  formation  of  the 
mould  and  core  is  a  matter  of  much  im- 
portance ;  each  being  formed  of  brick- 
work built  up  cylindrically,  and  of  such 
dimensions  that  the  larger  may  inclose 
the  former,  leaving  a  space  between  them 
equal  to  the  intended  thickness  of  the 
metal  cylinder.  The  outer  surface  of  the 
inner  cylinder,  or  core,  and  the  inner 
surface  of  the  outer  cylinder,  or  mould, 
are  wrought  very  smooth  and  regular; 
and  both  cylinders  being  adjusted  in  a 
pit,  melted  metal  is  poured  into  the  va- 
cuity between  them.  Thus  is  the  cylin- 
der formed.  The  process  of  boring,  to 
which  such  cylinders,  as  well  as  cannon 
and  other  articles  requiring  a  smooth  in- 
terior, are  afterwards  subjected,  is  not, 
as  the  name  seems  to  imply,  the  boring 
or  making  a  hole,  but  a  planing,  scrap- 
ing, or  cutting  away  of  the  inner  surface, 
till  it  becomes  regular  and  smooth  from 
end  to  end. 

In  all  large  specimens  of  casting,  such 
as  bed-plates  for  marine  engines,  arches 
for  bridges,  beams  for  roofs,  plates  for 
large  cisterns  aud  tanks,  turn-tables  for 
railways,  framework  for  engines  and  ma- 
chines of  various  kinds,  and  such  like, 
the  mould  is  made  in  sand  on  the  floor 
of  the  casting-house,  from  moulds  or 
patterns  previously  constructed  in  ac- 
cordance with  the  working  drawings, 
and  the  liquid  metal  is  poured  into  these 
moulds  at  once  from  the  blast-furnace, 
or  from  the  ponderous  vessels,  or  from 
a  cupola-furnace,  according  to  the  cir- 
cumstances of  the  case. 

FOUNT,  or  FONT,  among  printers, 
&c. ;  a  set  of  types,  sorted  for  use,  that 
incudes  running  letters,  large  and  small 


capitals,  single  letters,  double  letters, 
points,  commas,  lines,  numerals,  &c. ;  as 
a  fount  of  English,  of  Pica,  of  Bourgeois, 
&c.  A  fount  of  100,000  characters,  which 
is  a  common  fount,  would  contain  5000 
types  of  a,  3000  of  c,  11,000  of  «,  6000  of 
i,  3000  of  m,  and  about  30  or  40  of  k,  x, 
y,  and  z.  But  this  is  only  to  be  under- 
stood of  the  lower-case  types ;  those  of 
the  upper-case  having  other  proportions. 

A  small  fount  may  consist  of  fifty  or 
one  hundred  pounds  weight,  comprising 
the  usual  proportion  of  the  various  let- 
ters of  the  alphabet ;  and  a  large  fount, 
of  thirty  or  forty  thousand  pounds  weight, 
or  more. 

FOUNTAIN.  By  this  term  is  desig- 
nated any  natural  or  artificial  apparatus 
by  means  of  which  water  springs  up.  In 
natural  fountains  the  ascensional  effort 
is  produced  by  the  hydrostatic  pressure 
of  the  water  itself;  in  artificial  fountains 
it  is  produced  either  by  the  same  pres- 
sure, or  by  that  of  compressed  air,  or 
sometimes  "by  machinery. 

The  theory  of  natural  fountains  is  ex- 
tremely simple  :  it  depends  on  the  well- 
known  property  of  fluids,  which  when 
inclosed  in  tubes  or  vessels  communica- 
ting with  each  other,  the  fluid  rises  to 
the  same  level  in  all  of  the  tubes :  the 
pressure  on  the  sides  of  the  tube  at  any 
point  being  equal  to  the  height  of  the 
vertical  column  above  the  tube. 

Now  it  is  precisely  on  this  principle 
that  all  natural  fountains  are  explained. 
The  rain  which  falls  from  the  atmosphere 
is  absorbed  in  three  different  ways.  One 
part  of  it  collects  in  rills  on  the  surface  of 
the  ground ;  these  unite  in  streams  or 
rivulets,  which  flowing  into  one  another 
form  rivers,  and  thus  it  is  conveyed  to 
the  ocean.  A  second  part  is  taken  up  in 
giving  humidity  to  the  soil,  from  which 
it  is  returned  to  the  atmosphere  by  eva- 
poration. A  third  portion  descends  into 
the  earth,  through  soils  of  a  spongy  or 
porous  nature,  or  through  crevices  and  in- 
terstices in  the  strata,  until  it  meets,  fre- 
quently at  a  very  considerable  depth,  with 
strata  through  which  it  cannot  penetrate, 
and  is  then"  collected  in  subterraneous 
reservoirs.  When  confined  in  this  man- 
ner it  is  subject  to  the  pressure  of  the 
water  which  fills  the  channels  through 
which  it  has  descended ;  and  when  this 
pressure  is  sufficient  to  overcome  the  re- 
sistance of  the  superincumbent  mass  of 
earth,  the  water  breaks  the  artificial  stra- 
ta, and  gushes  forth  in  a  spring.  But  if 
the  strength  of  the  superincumbent  ma- 
terials exceed  the  hydrostatic  pressure, 


pre] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


187 


the  water  will  remain  stored  up  as  it 
were  in  the  subterraneous  reservoir. 
Now  if  the  ground  above  such  a  reser- 
voir, or  any  channel  communicating  with 
it,  be  perforated,  the  water,  having  free 
access  to  the  opening,  will  rise  in  it  till 
it  attains  the  level  of  the  highest  part  of 
the  channels  from  which  it  is  supplied. 
If  this  level  is  above  the  surface  of  the 
ground,  the  water  will  have  a  tendency 
to  rise ;  and  when  the  ascensional  force 
is  considerable,  it  may  by  proper  means 
be  formed  into  a  fountain.  That  subter- 
raneous reservoirs  formed  in  this  man- 
ner exist  in  great  abundance,  and  at  great 
depths  under  the  surface,  we  have  suffi- 
cient evidence  in  the  facility  with  which 
water  may  be  obtained  in  almost  all 
countries  from  Artesian  Wells. 

FOUNTAIN  OF  HERO.  An  ingeni- 
ous hydraulic  machine,  ascribed  to  Hero 
of  Alexandria,  who  lived  150  years  B.  C. 
Its  principle  depends  on  the  transmis- 
sion of  the  pressure  sustained  by  a  body 
of  water  in  one  vessel  to  that  in  another 
by  means  of  the  elasticity  of  air.  The 
essential  parts  of  the  fountain  consist  of 
two  close  vessels,  A  and  B.  The  one 
placed  somewhat  above  the  other,  and 
connected  by  a  frame ;  and  having  a  jet- 
pipe  in  the  centre,  its  lower  end  reaching 
near  the  bottom  of  A.  A  pipe  passes 
down  from  A  to  near  the  bottom  of  B : 
another  pipe  is  connected  with  B  nnd 
passes  up  to  near  the  top  of  A.  This 
pipe  conducts  air  from  B  to  A.  When 
water  is  poured  into  A  it  runs  down  the 
pipe  into  B ;  this  drives  the  air  up  the 
pipe  into  the  upper  part  of  A,  which 
presses  on  the  surface  of  the  water  there 
and  compels  it  to  pass  up  the  jet-pipe 
and  issue  out  as  a 
fountain,  the  height 
of  which  is  equal  to 
the  difference  of  the 
levels  of  the  water 
in  C  and  B :  the  wa- 
ter will,  according 
to  the  theory,  spout 
to  a  height  above 
its  level  in  A  equal 
to  that  distance. 
The  second  figure 
represents  the  foun- 
tain of  Hero  in  another  form.  An  appa- 
ratus of  this  kind  is  used  to  drain  the 
Hungarian  mines  at  Schemnitz. 

Artificial  fountains  are  also  produced 
by  means  of  the  elasticity  of  heated  air, 
or  air  condensed  by  some  other  means. 
Two  different  forms  are  used  for  this 
purpose.    The  first  consists  of  two  close 


vessels  of  tin,  placed  one  above  the  other; 
the  lower  one  Deing  of  considerable  size  : 
the  upper,  furnished  with  a  tube  or  jet, 
which  reaches  to  near  the  bottom  of  the 
vessel.  On  applying 
the  heat  of  a  lamp  to 
the  lower  vessel,  the  air 
within  it  expands  and 
forcing  its  way  through 
the  open  tube  is  com- 
pressed at  the  top  of 
the  vessel,  and  thus  by 
its  pressure  forces  the 
water  in  that  vessel 
through  K,  L,  forming 
a  small  jet  at  K.  This 
apparatus  being  generally  constructed  in 
the  form  of  a  temple,  produces  a  very 
pleasing  effect.     - 

FRANKFORT  BLACK.  Calcined  vine 
ashes,  and  refuse  lees  of  wine  manufac- 
tories. 

FRANKLINITE  is  a  compound  of  ox- 
ide of  iron,  with  the  oxides  of  mangan- 
ese and  zinc,  which  is  found  at  Frank- 
lin, N.  J.  It  crystallizes  in  octohedrons, 
which  occasionally  by  replacements  be- 
come nearly  globular.  It  commonly  oc- 
curs in  granular  masses  :  it  is  black,  brit- 
tle, and  has  much  of  the  appearance  of 
magnetic  iron,  but  somewhat  less  me- 
tallic, and  the  streak  is  reddish  brown. 
It  consists  of  iron  66,  oxide  of  zinc  17, 
and  oxide  of  manganese  16.  Its  sp.  gr. 
is  4-87.  It  is  found  accompanying  the 
red  oxide  of  zinc,  and  is  often  imbedded 
in  limestone,  and  mixed  with  garnets  and 
spinelle. 

FREEZING.  The  congelation  of  a  li- 
quid. When  cold  is  applied  to  any  sub- 
stance, its  particles  approximate,  so  that 
they  no  longer  have  the  same  freedom 
of  motion  among  themselves :  a  gas  or 
vapor  is  condensed  into  a  liquid.  Dis- 
tillation is  an  ordinary  example  of  this- 
If  the  cold  be  continued  still  further,  or, 
what  is  the  same  thing,  if  heat  contiuue 
to  be  abstracted,  the  liquid  gives  out 
heat,  and  ultimately  becomes  a  solid  ;  the 
freezing  of  water  and  other  liquids  are  ex- 
amples. Various  degrees  of  cold  are  re- 
quired to  bring  different  liquids  into  the 
solid  state,  and  tables  of  freezing  mix- 
tures have  been  made  to  accomplish  this 
end  artificially.  These  mixtures  are  com- 
binations of  various  salts,  which  react 
upon  each  other,  and  tend  continually  to 
pass  from  the  solid  to  the  liquid  state. 
They  hence  absorb  heat  from  every  thing 
producing  this  intense  cold. 

Dr.  Ure  gives  the  following  as  the  best 
proportions  for  producing  artificial  cold. 


188 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[fri 


MIXTURES  IN  PARTS 

Thermometer  sinks  from. 

Degree  of  cold 
produced. 

Phosphate  of  soda 

6) 

Nitrate  of  ammonia     . 

*T 

03  to  —84P 

34 

Diluted  nitric  acid 

4) 

Phosphate  of  soda 

8, 

Nitrate  of  ammonia     . 

2h 

_340to— ■ 50O 

16 

Diluted  mixed  acids     . 

4\ 

Snow     .... 
Diluted  nitric  acid 

5 

00  to  -^6° 

46 

Snow     .... 

8) 

Diluted  sulphuric  acid 

4 

— 10O  to  — 56° 

46 

Diluted  nitric  acid 

8f 

Snow     .... 
Diluted  sulphuric  acid 

il 

_20o  to  — 60° 

•10 

Snow     .... 
Muriate  of  lime    . 

S 

-f  2(P  to  -480 

63 

Snow     .... 
Muriate  of  lime    . 

3  t 

4  J 

+10O  to  —Mo 

64 

Snow     .... 
Muriate  of  lime    . 

2l 

.      3f 

—150  to  — 6SO 

63 

Snow     .... 
Cryst  muriate  of  lime 

:  H 

00  to  — 66o 

66 

Snow     .... 
Cryst  muriate  of  lime 

:  i 

-400  to  —  730 

33 

Snow     .... 
Diluted  sulphuric  acid 

■J\ 

—680  to  — 91o 

23 

FRENCH  CHALK  is  a  variety  of  talc, 
in  which  the  folia  arc  so  small  that  it  has 
a  somewhat  granular  texture  and  a  glim- 
mering: lustre. 

FRENCH  POLISH.  This  is  an  alco- 
holic solution  of  shellac,  some  of  the 
softer  resinous  gums  are  usually  added, 
but  too  much  of  them  renders  the  polish 
less  durable.  Highly  rectified  spirit,  not 
less  than  60  over  proof,  should  be  used. 
Rectified  wood  naptha  is  sometimes  sub- 
stituted, to  which  the  unpleasant  smell 
is  the  only  objection.  1st.  Orange  shel- 
lac 22  oz.',  rectified  spirits  4  pints,  dis- 
solve. 2d.  Shellac  3  oz.,  gum  sandarao  * 
oz.,  rectified  spirit  1  pint.  3d.  Shellac  4 
oz.,  gum  thus,  i  oz.,  rectified  spirit  1 
pint,  dissolve  and  add  almond  or  poppy 
oil,  2  oz.  4th.  Shellac  5  oz.,  oxalic  acid 
i  oz.,  rectified  spirit  1  pint,  dissolve  and 
add  linseed  oil  4  oz.  5th.  Shellac  10  oz., 
seed-lac  6  oz.,  gum  thus.  3  oz.,  sandarac 
6  oz.,  copal  varnish  6  oz.,  rectified  nap- 
tha, or  dissolve  8  oz.  each  of  seed-lac, 
gum  thus,  and  sandarac,  separately  in  a 
pint  of  naptha ;  and  1  lb.  ot  shellac  in  8 
pints  of  naptha.  Then  mix  6  oz.  of  co- 
pal varnish,  12  oz.  of  solution  of  seed-lac, 
6  oz.  of  solution  of  frankincense,  and  12 
of  solution  sandarac,  and  Bf  lbs.  solution 
of  shellac.  Let  the  copal  varnishes  be 
put  into  a  tincture  of  shellac,  and  well 
shaken,  and  the  other  ingredients  be 
added.  A  correspondent  iaiprms  us 
that  this  polish  cannot  be  excelled.  6th. 
Copal  {  oz.,  gum  arabic  $  oz.,  shellac  1 


oz.,  pulverize,  mix,  and  sift  the  powders, 
and  dissolve  in  a  pint  of  spirit. 

French  polish  is  sometimes  colored 
with  dragon's  blood,  turmeric  root,  &c. 
The  general  directions  for  preparing  the 
polish  are  to  put  the  gums  with  the  spi 
rit  in  a  tin  bottle,  and  set  it  on  the  stove 
or  in  water,  so  as  to  keep  it  at  a  gentle 
heat,  shaking  it  frequently.  The  cork 
should  be  loosened  a  little  before  shak- 
ing it,  taking  care  that  there  is  no  flame 
near  to  kindle  the  vapor.  When  the 
gums  are  dissolved  let  it  settle  for  a  few 
hours,  and  pour  off  the  solution  from 
the  dregs.  The  method  of  using  it  is  to 
have  a  roll  of  list,  over  the  end  of  which 
five  or  six  folds  of  linen  rags  are  placed. 
The  polish  is  applied  to  the  linen  with  a 
sponge  and  a  little  linseed  oil  is  dropped 
on  the  centre  of  it. 

FRICTION.  In  Mechanics,  the  resist- 
ance produced  by  the  rubbing  of  the  sur- 
faces of  two  solid  bodies  against  each 
other.  If  the  surfaces  of  bodies  were 
perfectly  smooth  and  polished,  they 
would  slide  along  one  another  without 
suffering  any  resistance  from  their  con- 
tact, and  all  the  simple  relations  between 
power  and  resistance  determined  by  the- 
ory in  respect  of  the  different  machines 
would  hold  good  without  any  modifica- 
tion whatever.  But  this  state  of  perfect 
polish  never  exists.  The  surfaces  of  all 
bodies  with  which  we  are  acquainted, 
even  when  most  carefully  polished,  re- 
tain a  greater  or  less  degree  of  asperity, 


FRl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


189 


which  prevents  them  from  sliding  over 
one  another  without  impediment ;  and  in 
many  cases  the  resistance  thus  created 
amounts  to  a  large  proportion  of  the 
whole  resistance  to  be  overcome.  In  or- 
der, therefore,  to  ascertain  the  real  value 
of  the  effect  of  powers  applied  to  machin- 
ery, it  is  necesaary  to  determine  the 
amount  of  the  friction,  and  to  add  this 
new  resistance  to  that  which  is  given  by 
the  theory  of  mechanics. 

The  determination  of  the  laws  of  fric- 
tion, and  its  amount  with  respect  to  par- 
ticular substances,  have  occupied  the  at- 
tention of  many  experimental  philoso- 
phers and  mathematicians,  as  Amontons, 
Euler,  Desaguliers,  Vince,  &c. ;  but  the 
first  complete  set  of  experiments  on  the 
the  subject  was  made  by  Coulomb  about 
the  year  1780.  His  results,  though  they 
have  been  partly  modified  by  subsequent 
experiments,  throw  much  light  upon  the 
subject,  and  are  of  great  value  to  the 
practical  engineer. 

There  are  two  modes  by  which  the  na- 
ture and  operation  of  friction  may  be  as- 
certained. The  first  is  very  simple,  and 
consists  in  merely  placing  a  heavy  body 
on  a  horizontal  plane,  and  elevating  the 
end  of  the  plane  till  the  body  begins  to 
slide.  When  this  motion  commences,  it 
is  evident  that  the  force  of  gravity  just 
begins  to  exceed  the  resistance  occa- 
sioned by  the  friction ;  and  as  the  gravi- 
ty is  known  from  the  weight  of  the  body, 
and  the  inclination  of  the  plane,  we  have 
thus  the  means  of  comparing  the  friction 
with  a  given  force. 

But  this  method  is  liable  to  some  un- 
certainty. Most  bodies,  after  having 
been  in  contact  for  some  time,  require  a 
greater  force  to  originate  than  to  keep  up 
progressive  motion ;  but  it  is  obvious 
that  the  inclination  of  the  plane  of  de- 
scent marks  only  the  initial  obstruction. 
Coulomb  accordingly  adopted  a  different 
mode  of  proceeding.  His  general  me- 
thod was  to  draw  a  sort  of  loaded  sledge 
along  a  horizontal  bench,  by  means  of 
weights  placed  in  a  dish  attached  to  the 
sledge  by  a  cord  passing  over  a  pulley. 
The  sledge  was  mounted  on  sliders  of 
the  substance  on  which  the  experiments 
were  to  be  made ;  and  the  corresponding 
slips  of  the  same  or  a  different  substance 
placed  upon  the  sliders  on  the  bench. 
This  apparatus  has  been  called  a  tribome- 
ter.  The  following  are  some  of  the  re- 
sults which  were  obtained. 

Assuming  the  pressure  as  equal  to  100 
parts,  the  friction  of  oak  against  fir  was 
66  in  the  direction  of  the  fibres,  but 


amounted  only  to  16  when  moved  with 
the  velocity  of  a  foot  each  second:  the 
friction  of  oak  against  oak  in  the  direc- 
tion of  the  fibres  was  43,  and  across  them 
only  27,  the  effect  being  still  reduced  by 
motion  to  10 ;  the  friction  of  fir  against 
fir  in  the  direction  of  the  fibres  was  56, 
which  sunk  to  seventeen  during  motion  ; 
the  friction  of  elm  against  elm  in  the  di- 
rection of  the  fibres  was  46,  and  reduced 
by  motion  to  10.  On  the  other  hand, 
the  friction  of  copper  upon  oak,  length- 
wise, was  8  at  the  commencement  of  the 
motion,  but  increased  to  18  when  the 
velocity  was  a  foot  in  a  second ;  the  fric- 
tion of  iron  upon  oak  with  the  initial 
velocity  was  11,  and  was  increased  by  the 
motion  to  18.  But  the  mutual  friction 
of  metals  appeared  in  general  to  be  scarce- 
ly, if  at  all,  affected  by  motion.  In  these 
experiments  no  unguents  were  used. 

Where  metals  rub  against  wood,  it  is 
necessary  that  the  two  bodies  continue 
longer  in  contact,  in  order  that  the  fric- 
tion may  acquire  its  maximum.  In  the 
case  of  iron  against  wood  at  least  4  or  5 
hours  must  elapse  before  the  momentary 
increase  of  friction  disappears  ;  whereas 
in  the  case  of  wood  against  wood  a  sin- 
gle minute  was  sufficient.  But  the  re- 
sistance appears  to  increase  by  contact, 
though  less  sensibly,  even  for  several 
days.  The  application  of  grease  to  the 
surfaces  of  wood  produces  a  similar  ef- 
fect, and  the  resistance  does  not  attain 
its  maximum  till  after  a  very  considerable 
time.  At  the  end  of  5  or  six  days  the 
resistance  is  perhaps  14  times  greater 
than  it  was  at  the  first  instant,  if  the  sur- 
face of  contact  is  considerable  in  respect 
of  the  pressure ;  but  when  the  surface  is 
small,  the  friction  reaches  its  maximum 
much  more  quickly. 

An  important  part  of  the  investigation 
was  to  ascertain  whether  the  friction  is 
increased  by  the  velocity  of  the  rubbing 
bodies.  "VVith  respect  to  the  bodies  of 
the  same  kind  descending  on  inclined 
planes,  Coulomb  found  that  the  time  re- 
quired for  passing  over  the  first  half  was 
a  little  more  than  double  that  required 
for  passing  over  the  second.  But  a  body 
put  in  motion  by  a  constant  accelerating 
force  employs  for  passing  over  one  space, 
and  over  two  equal  consecutive  spaces, 
times  that  are  to  each  other  in  the  ratio 
of  v'l :  V2=100  :  142  ;  that  is  to  say,  if 
100  units  of  time  are  consumed  in  pass- 
ing over  the  first  space,  142  will  be  con- 
sumed in  passing  over  the  first  and  se- 
cond together,  and  consequently  42  in 
passing    over   the    second.      Now   this 


190 


CYCLOPEDIA    OP    THE    USEFUL    ARTS. 


[fri 


agrees  as  nearly  as  possible  with  the  re- 
sult of  the  experiments ;  consequently 
we  infer  that  a  load  drawn  along  a  smooth 
plane  by  a  constant  accelerating  force 
(that  of  a  descending  weight  for  exam- 
ple) is  uniformly  accelerated.  But  this 
requires  that  the  friction,  at  every  in- 
stant, destroys  only  a  proportional  quan- 
tity of  the  force  added  by  the  constant 
action  of  gravity.  The  conclusion  there- 
fore is,  that  for  moderate  velocities  at 
least,  the  resistance  due  to  friction  is  a 
constant  quantity,  and  very  nearly  the 
same  for  every  degree  of  velocity. 

Another  point  of  great  importance  was 
to  ascertain  the  relation  the  friction  bears 
to  the  pressure ;  for  example,  in  what  ra- 
tio the  friction  has  increased  by  doubling 
or  trebling  the  load.  Coulomb  found 
that  when  wood  has  been  allowed  to  rest 
on  wood  for  some  time,  without  the  in- 
tervention of  any  unguent,  the  resistance 
occasioned  by  the  friction  is  proportional 
to  the  pressure.  The  resistance  for  a 
short  time  increases  rapidly  by  the  con- 
tact, but  attains  its  maximum  in  a  few 
minutes.  The  friction  of  wood  sliding 
on  wood  with  any  velocity  is  still  propor- 
tional to  the  pressure  ;  but  the  resistance 
is  much  less  in  amount  than  that  which 
is  required  to  detach  the  surfaces  after 
some  minutes  of  contact.  In  the  case  of 
oak,  for  instance,  the  force  required  to 
detach  the  surfaces  after  being  some  mi- 
nutes in  repose  is  to  that  which  is  neces- 
sary to  overcome  friction  alone  after  mo- 
tion has  commenced  in  the  ratio  of  100 
to  23.  The  friction  of  metals  on  metals 
is  also  proportional  to  the  pressure  ;  but 
the  intensity  is  the  same,  whether  the 
surfaces  have  been  any  length  of  time  in 
contact,  at  rest,  or  are  gliding  along  with 
a  uniform  velocity. 

The  friction  of  heterogeneous  sub- 
stances, as  woods  and  the  metals,  is  en- 
tirely different  from  the  above.  In  the 
case  of  wood  against  wood  dry,  or  of  me- 
tal against  metal,  the  friction  of  the  rub- 
bing" bodies  is  very  little  influenced  by 
the  velocity ;  but  in  the  present  case 
the  friction  increases  very  sensibly  with 
an  augmented  velocity.  Coulomb  in- 
ferred that  the  friction  increased  as  the 
natural  numbers,  when  the  velocities  are 
increased  as  the  squares  of  those  num- 
bers. In  all  cases  of  a  hard  body  rub- 
bing against  a  very  soft  substance,  the 
friction  increases  remarkably  with  the 
velocity. 

Since  the  friction  is  in  general  propor- 
tional to  the  pressure,  it  follows  that  it 
will  not  be  altered  by  increasing  or  di- 


minishing the  extent  of  the  rubbing  sur- 
faces. Nevertheless,  this  consequence 
fails  in  the  extreme  cases.  The  friction 
is  sensibly  diminished  when  the  surfaces 
in  action  are  reduced  to  the  smallest  di- 
mensions. Thus,  while  the  friction  of  a 
ruler^  of  brass  against  a  similar  one  of 
iron  is  expressed  by  26,  it  was  found  to 
be  only  17  after  the  sledge  had  been 
mounted  on  4  round-headed  brass  nails. 

Other  causes  of  friction  are  the  rough- 
nesses, spieulae,  and  angles  of  surfaces 
removeable  by  filling  them  with  oil-tal- 
low, &c,  and  by  diminishing  the  extent 
of  surface  in  contact.  Olive-oil  reduces 
the  friction  of  woods  one-half. 

In  all  cases,  the  rubbing  of  large  sur- 
faces against  each  other  should  be  avoid- 
ed ;  and  hence  the  use  of  litti  i  wheels  to 
turn  with  the  axis  of  shafts  called  friction- 
wheels,  by  which  the  contact  and  rub- 
bing of  large  breadths  is  avoided.  Differ- 
ent substances,  too,  should  work  against 
one  another,  the  ultimate  atoms  of  the 
bodies  tending  to  combine  by  their  simi- 
larity of  forms. 

In  the  screw  and  the  wedge,  the  fric- 
tion is  equal  to  the  power.  The  sheaves 
of  pullies  should  not  press  against  the 
blocks. 

It  has  been  carefully  determined  at 
Baltimore,  that  one  quart  of  oil  is  suffi- 
cient for  2000  miles  run  of  a  steam-car- 
riage weighing  3  tons.  In  the  Winan's 
waggon,  the  friction- wheels  dip  into  the 
oil ;  but  being  in  a  cast-iron  case,  none  is 
lost,  while  the  renewal  of  oil  is  better 
than  the  same  in  long  work.  Purified  ve- 
getable oils  answer  best. 

Black-lead  is  found  to  destroy  friction 
with  the  best  effect. 

Ferguson  found  that  the  quantity  of 
friction  was  always  proportional  to  the 
weight  of  the  rubbing  body,  and  not  to 
the  quantity  of  surface ;  and  that  it  in- 
creased with  an  increase  of  velocity,  but 
was  not  proportional  to  the  augmenta- 
tion of  celerity.  He  found  also,  that  the 
friction  of  smooth  soft  wood,  moving  up- 
on smooth  soft  wood,  was  equal  to  one- 
third  of  the  weight ;  of  rough  wood  upon 
rough  wood,  one  half  of  the  weight;  of 
soft  wood  upon  hard,  or  hard  upon  soft, 
one-fifth  of  the  weight ;  of  polished  steel 
upon  polished  steel  or  pewter,  one  quar- 
ter of  the  weight ;  of  polished  steel  upon 
copper,  one-fifth ;  and  of  polished  steel 
upon  brass,  one  sixth  oi  the  weight. 
Coulomb  brought  to  light  many  new  and 
striking  phenomena,  and  coufirmed 
others,  which  were  previously  but  par- 
tially established. 


fue] 


CYCLOPEDIA    OF   THE    USEUL   ARTS. 


191 


The  obstruction  which  a  cylinder  meets 
with  in  rolling  along  a  smooth  plane  is 
quite  distinct  in  its  character,  and  far  in- 
ferior in  its  amountj  to  that  which  is 
f>roduced  by  the  friction  of  the  same  cy- 
inder  drawn  lengthwise  along  a  plane. 
For  example,  in  the  case  of  wood  rolling 
on  wood,  the  resistance  is  to  the  pressure, 
if  the  cylinder  be  small,  as  16  or  18  to 
1000 ;  and  if  the  cylinder  be  lame,  this 
may  be  reduced  to  6  to  1000.  The  fric- 
tion from  sliding,  in  the  same  cases, 
would  be  to  the  pressure  as  2  to  10,  or 
3  to  10,  according  to  the  nature  of  the 
wood.  Hence,  by  causing  one  body  to 
roll  on  another,  the  resistance  is  dimin- 
ished from  12  to  20  times.  It  is  there- 
fore a  principle  in  the  composition  of 
machines,  that  attrition  should  be  avoid- 
ed as  much  as  possible,  and  rolling  mo- 
tions substituted  whenever  circumstances 
admit. 

On  this  principle  depends  the  advan- 
tages resulting  from  the  application  of 
f notion  wheels  and  friction  rollers.  The 
extremity  of  an  axle,  instead  of  resting 
in  a  cylindrical  socket,  is  made  to  rest  on 
the  circumference  of  two  wheels,  to  the 
axles  of  which  the  friction  is  transferred, 
and  consequently  diminished  in  the  ra- 
tio of  the  radius  of  the  wheel  to  the  radi- 
us of  the  axle.  This  ingenious  contriv- 
ance appears  to  have  first  been  applied  by 
Henry  bully,  in  the  year  1716. 

Soapstone  has  been  used  for  diminish- 
ing motion  with  great  profit  and  success. 
It  is  first  thoroughly  pulverized,  and  then 
mixed  with  oil,  tallow,  lard,  or  tar.  It  is 
used  in  all  kinds  of  machinery  where  it 
is  necessary  to  apply  any  unctuous  sub- 
stance to  diminish  friction,  and  it  is  an 
excellent  substitute  for  the  usual  compo- 
sition applied  to  carriage  vehicles. 

Perkins  has  avoided  the  necessity  of 
employing  oil,  grease,  or  any  other  lubri- 
cator to  the  piston  of  the  steam  engine  by 
forming  his  piston  of  bell-metal,  com- 
posed of  the  following  materials  : — cop- 
per, 20  parts ;  tin,  5  parts  ;  zinc,  1  part. 
This,  as  well  as  his  cast-iron  cylinder,  is 
cast  under  the  pressure  of  a  considerable 
head  of  metal ;  by  which  means  the  den- 
sity and  closeness  of  grain  of  both  of 
them  is  very  greatly  increased,  and  in- 
deed, the  cast-iron  has  as  close  a  grain  as 
wrought-iron  itself.  These  two  metals 
he  finds  to  act  so  as  to  polish  each  other  in 
use.  He  also  uses  the  same  dense  cast- 
iron  to  form  his  steam-engine  crank- 
axes,  and  the  spindles  of  axes  of  his 
grindstones,  &c.,  with  ;  and  he  runs  the 
cylindrical  necks  of  them  upon  bearings 


formed  of  his  bell-metal,  placed  under- 
neath them,  and  made  with  hollow  cylin- 
drical cavities,  across  their  upper  faces, 
not  exceeding  the  sixth  part  of  a  circle  in 
extent ;  and  yet,  upon  these  very  small 
bearings,  his  necks  run,  with  a  very  tri- 
fling portion  indeed  of  grease,  as  a  lubri- 
cator. In  thi3  manner,  the  cylindrical 
necks  of  the  axis  of  a  large  grindstone, 
employed  in  grinding  large  articles,  run  ; 
and  yet,  on  throwing  off  the  band  from 
the  rigger,  or  band-wheel,  the  stone  will 
make  fifty  revolutions  at  least  before  it 
stops. 

FUEL.  Any  combustible  substance 
which  is  used  for  the  production  of  heat, 
constitutes  a  species  of  fuel ;  and  in  this 
extended  sense  of  the  term,  alcohol,  wax, 
tallow,  coal  gas,  oil,  and  other  inflamma- 
ble bodies  which  are  occasionally  used, 
especially  in  the  chemical  laboratory,  as 
sources  of  heat  as  well  as  light,  might  be 
included  under  it.  But  the  term  fuel  is 
more  properly  limited  to  coal,  coke,  char- 
coal, wood,  and  a  few  other  substances, 
which  are  our  common  sources  of  heat, 
and  as  such  are  burned  in  grates,  stoves, 
fireplaces,  and  furnaces  of  different  de- 
scriptions. 

In  this  country,  coal,  In  the  neighbor- 
hood of  cities,  is  the  fuel  commonly 
employed  ;  but  where  wood  is  abun- 
dant, or  where  its  value  is  little  more 
than  that  of  felling  it,  it  is  used  either  in 
its  original  state  or  in  the  form  of  char- 
coal. But  whatever  substance  is  used,  the 
ultimate  elements  of  fuel  are  carbon  and 
hydrogen  ;  and  the  heat  which  is  evolv- 
ed by  their  combustion  is  derived  from 
their  combination  at  high  temperatures 
with  the  oxygen  of  the  air:  the  results  or 
products  of  this  combustion  are  carbonic 
acid  and  water,  these  escaping  into  the 
atmosphere  by  the  flue  or  chimney  gene- 
rally attached  to  furnaces  and  fireplaces. 

It  is  essential  to  good  and  profitable 
fuel  that  it  should  be  free  from  moisture ; 
for  unless  it  be  dry,  much  of  the  heat 
which  it  generates  is  consumed  in  con- 
verting its  moisture  into  vapor  :  hence 
the  superior  value  of  old,  dense,  and  dry 
wood,  to  that  which  is  porous  and  damp  ; 
hence  also  the  greater  quantity  of  heat 
evolved  during  the  combustion  of  char- 
coal as  compared  with  that  of  wood,  for 
even  the  driest  wood  always  retains  a 
certain  quantity  of  water  ;  hence  also 
coke  gives  out  more  heat  than  pit  coal, 
partly  because  it  is  absolutely  dry,  and 
partly  because  during  the  combustion  or 
heating  of  coal,  tar,  oil,  water,  and  gas 
are  evolved,  all  of  which  carry  off  a  cer- 


192 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[fue 


tain  proportion  of  the  heat  in  a  latent 
form.  A  pound  of  dry  wood  will,  for  in- 
stance, heat  35  pounds  water  from  32° 
to  212°,  and  a  pound  of  the  same  wood 
in  a  moist  or  fresh  state  will  not  heat 
more  than  25  pounds  from  the  same  to 
the  same  temperature ;  the  value,  there- 
fore, of  different  woods  for  fuel  is  nearly 
inversely  as  their  moisture,  and  this  may 
be  roughly  ascertained  by  finding  how 
much  a  given  weight  of  their  shavings 
loses  by  drying  them  at  212°. 

Charcoal  is  itself  very  hygrometric,  and 
when  exposed  to  air  increases  in  weight 
to  the  amount  of  10  or  12  per  cent,  in 
consequence  of  the  absorption  of  humi- 
dity :  a  pound  of  dry  charcoal  is  capable 
of  raising,  when  properly  burned,  73 
pounds  of  water  from  the  freezing  to  the 
boiling  point. 

The  different  kinds  of  pit  coal  give  out 
variable  quantities  of  heat  during  their 
combustion;  upon  an  average,  one  pound 
of  coal  should  raise  60  pounds  of  water 
from  the  freezing  to  its  boiling  point. 
The  heating  power  of  coke  as  compared 
with  coal  is  nearly  in  the  ration  of  75  to 
69  :  a  pound  of  good  coke  will  heat  from 
64  to  66  pounds  of  water  from  32°  to 
212° ;  its  power,  therefore,  is  about  nine- 
tenths  that  of  wood  charcoal. 

The  value  of  turf  and  peat  as  fuel  is 
liable  to  much  variation,  and  depends 
partly  upon  their  density,  and  partly 
upon  their  freedom  from  earthy  impuri- 
ties. A  pound  of  turf  will  heat  about  26 
pounds  of  water  from  32°  to  212°,  and  a 
pound  of  dense  peat  about  30  pounds  : 
by  compressing  and  drying  peat  its  value 
as  a  fuel  is  greatly  increased. 

The  following  table,  by  Dr.  Ure,  shows 
the  quantity  of  water  raised  from  32°  to 
212°  by  one  pound  weight  of  the  dif- 


Combustible. 

Pounds  of 
Water     which 
a    Pound    can 
raise   from  32° 

to  212°. 

<_  —  a  • 

Weight  of 
Atinoaohfric 
Air  at  fcr*  re- 
quired to  buru 
one  Pound. 

Dry  wood .    .    . 
Common  wood  . 
Charcoal    .    .    . 
Pit  coal.    .    .    . 
Coke     .... 

Turf 

Coal  gas     .    .    . 
Oil,  wax,  or  tallow 
Alcohol      .    .    . 

35-00 
26-00 
73-00 
60-00 
65-00 
30-00 
7600 
78-00 
52-00 

6-36 

4-72 
13-27 
10-90 
11-81 

5-45 
13-81 
14-18 

9-56 

5-96 

4-47 
11-46 

9-26 
11-46 

4-60 
14-58 
15-00 
11-60 

ferent  combustibles  enumerated  in  the 
first  column;  it  also  shows  the  number 
of  pounds  of  boiling  water,  which  the 
same  weight  of  fuel  will  evaporate,  and 


the  quantity  of  atmospheric  air  absolute- 
ly consumed  during  combustion.  The 
quantity  of  air,  however,  as  given  in  the 
last  column,  is  much  less  than  would  be 
necessary  in  practice,  where  much  of  the 
air  passes  the  fuel  without  coming  into 
contact  with  it  so  as  have  its  oxygen  con- 
sumed. The  heating  power  also,  as  re- 
presented by  this  table,  can  seldom  bo 
practically  attained. 

Fuel,  Artificial.  Coal,  in  its  natural 
state,  consists  principally  of  bitumen, 
carbon,  and  some  earthy  matters.  All 
fuel  contain  substances  possessing  bitu- 
minous and  carbonaceous  properties. 
Various  compounds  have  been  brought 
forward  from  time  to  time,  some  of  them 
patented,  to  produce  artificial  fuel.  All 
those  compounds  have  been  combina- 
tions of  substances  of  a  carbonaceous 
and  bituminous  nature,  capable  of  gene- 
rating inflammable  gas  and  sustaining 
combustion.  Among  the  first  compounds 
was  refuse  coal  dust,  with  pitch,  which 
was  capable  of  producing  an  intense  heat. 
A  patent  was  taken  out  in  London,  in 
1800,  by  a  Mr.  P.  Davy,  for  an  artificial 
fuel,  to  burn  without  smoke  or  sulphur- 
ous smell.  It  was  composed  of  sea  coal 
dust  mixed  with  charcoal,  tanners'  bark, 
and  saw-dust.  The  materials  were  mix- 
ed together  wet,  placed  in  a  kilu  and 
slightly  cooked,  care  being  taken  not  to 
use  too  high  a  temperature.  Another 
artificial  fuel  was  to  place  upon  a  shelf, 
above  the  fire,  a  quantity  of  chalk,  or 
lime,  which  becoming  heated  from  the 
combustion  of  the  coal  below,  concen- 
trated the  heat  for  a  long  time.  Another 
plan  was  to  bake  bituminous  and  anthra- 
cite coal  together,  to  produce  a  very  last- 
ing coke.  The  proportions  were  one- 
third  of  the  bituminous.  Another  plan 
was  that  of  a  Mr.  T.  Sunderland,  who 
took  out  a  patent  for  a  compound  of  gas- 
tar,  clay,  saw-dust,  tanners'  bark,  and 
refuse  dye  wood ;  all  were  mixed  toge- 
ther, formed  into  cakes,  and  dried  by 
any  artificial  heat.  Another  compound, 
and  patented  too,  was  saw-dust,  spent 
bark,  coke,  cinder  ashes,  and  clay,  re- 
duced to  powder,  mixed,  cut  and  dried 
into  cakes,  and  then  dipped  into  coal  tar, 
or  grease,  and  afterwards  dried.  An- 
other compound  was  peat,  clay,  nitre, 
alum,  linseed  and  resin,  all  ground  in  a 
mill  and  pressed  into  moulds,  like  bricks, 
and  afterwards  dried  in  the  sun.  An- 
other, and  an  ingenious  plan,  to  harden 
peat,  or  swamp  earth,  was  to  mix  it  with 
powdered  coal,  or  powdered  brimstone, 
to  break  up  the  fibres  and  deprive  the 


ful] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


19« 


peat  or  swamp  earth  of  its  water,  after- 
wards pressing  it  and  making  it  into 
hard  blocks.  Another  compound,  by  a 
Mr.  Stirling,  patented  in  England,  was 
to  mix  pulverized  coal  with  tar  and  clay. 
All  were  intimately  mixed  together, 
moulded  into  blocks  and  dried,  and  then 
they  were  excellent  in  shape  for  stowage. 
The  great  object  of  the  producers  of  arti- 
ficial fuel  has  been  to  make  it  in  such  a 
shape  that  it  would  be  easily  stowed 
away  for  sea  voyages,  but  the  expense 
always  exceeded  the  benefits.  We  might 
enumerate  a  great  number  of  compounds 
of  the  above  nature,  varying  but  little 
from  one  another,  but  which  constitute 
the  subjects  of  no  less  than  twenty-one 
patents,  recorded  in  the  London  Reper- 
tory  of  Arts,  and  in  the  List  of  American 
Patents.  Very  favorable  accounts  are 
given  of  using  the  gas-tar  along  with 
spent-tan  bark,  in  the  gas-works,  to  heat 
the  retorts.  A  patent  was  taken  out  in 
Washington,  last  year,  for  the  compress- 
ing of  coal  dust  into  fuel.  Another  kind 
is  made  at  Newton's  Corners,  near  Al- 
bany, N.  Y.,  by  grinding  swamp  muck 
in  a  pug  mill,  then  submitting  it  to  a 
very  severe  pressure,  and  afterwards 
drying  it.  It  is  represented  to  burn 
well. 

We  know  of  no  kind  of  fuel,  taking  it 
for  all  in  all,  that  can  equal  the  anthra- 
cite. It  is  compact  and  cleanly,  good 
qualities  certainly;  but  it  has  another, 
viz.,  great  and  enduring  calorific  qualities. 
Bituminous  coal  is  good  fuel,  but  very 
uncleanly,  for  domestic  use  especially. 
One  thing  can  make  its  use  more  agree- 
able, namely,  to  burn  the  smoke.  This 
can  be  done  by  injecting  fine  jets  of  air 
on  the  top  of  the  coals. 

FULLER'S  EARTH  is  a  soft,  friable, 
coarse  or  fine  grained  mass  of  lithomarge 
clay.    Its  color  is  greenish,  or  yellowish 

f^ray ;  it  is  dull,  but  assumes  a  fatty 
ustre  upon  pressure  with  the  fingers, 
feels  unctuous,  does  not  adhere  to  the 
tongue,  and  has  a  specific  gravity  vary- 
ing from  1*82  to  2*19.  It  falls  down  readi- 
ly in  water,  into  a  fine  powder,  with  ex- 
trication of  air  bubbles,  and  forms  a 
non-plastic  paste.  It  melts  at  a  high 
heat  into  a  brown  slag.  Its  constituents 
are  53-0  silica;  10*0  alumina;  9-75  red 
oxide  of  iron;  1*25  magnesia;  0*5  lime;  24 
water,  with  a  trace  of  potash.  Its  cleans- 
ing action  upon  woollen  stuffs  depends 
upon  its  power  of  absorbing  greasy  mat- 
ters. It  should  be  neither  tenacious  nor 
sandy  ;  for  in  the  first  case  it  would  not 
diffuse  itself  well  through  water,  and  in 


the  second  it  would  abrade  the  cloth  too 
much.  The  finely  divided  silica  is  one 
of  its  useful  ingredients. 

After  baking  it  is  thrown  into  cold  wa- 
ter, where  it  falls  into  powder,  and  the 
separation  of  the  coarse  from  the  fine  is 
effectually  accomplished,  by  a  simple 
method  used  in  the  dry  color  manufac- 
tories, called  washing  over.  It  is  done 
in  the  following  manner :  Three  or  four 
tubs  are  connected  on  a  line  by  spouts 
from  their  tops  ;  in  the  first  the  earth  is 
beat  and  stirred,  and  the  water,  which  is 
continually  running  from  the  first  to  the 
last  through  intermediate  ones,  carries 
with  it  and  deposites  the  fine,  whilst  the 
coarse  settles  m  the  first.  The  advan- 
tages to  be  derived  from  this  operation 
are,  that  the  two  kinds  will  be  much 
fitter  for  their  respective  purposes  of 
cleansing  coarse  or  fine  cloth  ;  for  with- 
out baking  the  earth  they  would  be  unfit, 
as  before  noticed,  to  incorporate  so  mi- 
nutely with  the  water  in  its  native  state ; 
it  would  neither  so  readily  fall  down,  nor 
so  easily  be  divided  into  different  quali- 
ties, without  the  process  of  washing  over". 
When  fuel  is  scarce  for  baking  the  earth, 
it  is  broken  into  pieces  of  the  same  size, 
as  mentioned  above,  and  then  exposed 
to  the  heat  of  the  sun. 

The  benefit  of  fuller's  earth  is  mainly 
due  to  the  alumina,  which,  by  rubbing 
on  the  cloth  unites  with  the  grease,  form* 
ing  a  soap  which  may  either  be  washed^ 
or  may  serve  as  a  mordant  to  fix  the  co- 
lors better  on  the  stuffs. 

FULLING.  The  art  of  cleansing, 
scouring,  and  pressing  stuffs,  cloths, 
stockings,  &c,  to  render  them  stronger, 
firmer,  and  closer ;  it  is  also  called  mill- 
ing, because  these  cloths,  &c,  are  in  fact 
scoured  bv  a  water  mill. 

FULMINATES.  Compounds  of  the 
fulminic  acid  with  various  bases,  all  more 
or  less  possessed  of  the  property  of  ex- 
ploding or  detonating  by  heat  or  friction. 
The  fulminates  of  silver  and  mercury  (or 
fulminating  silver  and  mercury)  are  ob- 
jects of  manufacturing  interest ;  the  for- 
mer being  used  in  detonating  bonbons, 
and  the  latter  more  largely  and  impor- 
tantly as  a  priming  for  the  percussion 
caps  of  gun  locks. 

FULMINATING  POWDER.  A  com- 
pound of  three  parts  of  nitre,  two  of 
purified  pearlash,  and  one  of  flowers  of 
sulphur,  carefully  mixed  and  dried  be- 
fore the  fire  :  about  20  grains  of  this 
powder  heated  upon  an  iron  plate  over  a 
slow  fire  becomes  brown  and  pasty  j  a 
blue  flame  then  appears  upon  it,  ana  im» 


194 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[fur 


mediately  after  the  whole  explodes  with 
a  stunning'  report. 

FUNNEL.  In  architecture,  the  upper 
part  of  a  chimney.  In  common  life,  it  is 
a  trumpet-mouthed  utensil,  with  a  pipe 
fixed  to  the  apex  for  the  purpose  of  con- 
veying liquors  into  a  vessel  without  spill- 
ing them. 

FUMIGATION,  is  the  employment  of 
fumes  or  vapors  to  purify  articles  of  ap- 
parel, and  goods  or  apartments  supposed 
to  be  imbued  with  some  infectious  or 
contagious  poison  or  fumes.  The  vapors 
of  vinegar,  the  fumes  of  burning  sulphur, 
explosion  of  gunpowder,  have  "been  long 
prescribed  and  practised,  but  they  have 
m  all  probability  little  or  no  efficacy. 
The  diffusion  of  such  powerful  agents  as 
chlorine  gas,  muriatic  acid  gas,  or  nitric 
acid  vapor,  should  alone  be  trusted  to  for 
the  destruction  of  morbific  effluvia. 

FUNICULAR  MACHINE.  In  mecha- 
nics, if  a  body  fixed  to  two  or  more  ropes 
is  sustained  by  powers  which  act  by 
means  of  those  ropes,  the  assemblage 
is  called  the  funicular  ?nachine,  or  rope 
machine.  If  a  rope  is  stretched  horizon- 
tally between  two  points,  its  own  weight 
alone  will  prevent  it  from  becoming  per- 
fectly straight,  whatever  force  be  em- 
ployed in  stretching  it ;  and  a  very  small 
force  applied  at  its  middle  point,  at  right 
angles  to  its  direction,  will  be  sufficient 
to  overcome  a  very  great  resistance  at 
the  points  to  which  its  extremities  are 
attached.  In  this  manner  a  very  small 
force  may  be  made  to  raise  a  very  great 
weight  to  a  minute  height.  This  method 
of  applying  force  is  familiar  to  seamen, 
who  frequently  have  recourse  to  it  in 
bracing  their  sails. 

FUR.  The  coated  skins  of  wild  ani- 
mals, especially  of  those  of  high  northern 
latitudes  ;  such  as  the  wolf,  bear,  beaver, 
&c.  The  hair  of  fur  is  cleansed,  and  the 
skin  is  generally  slightly  tanned  or  taw- 
ed. The  most  valuable  furs,  such  as 
ermine  and  sable,  come  chiefly  from 
Russia.  When  unprepared,  or  merely 
dried,  the  fur  skins  go  under  the  name 
of peltry. 

FURNACES  bear  various  names,  ac- 
cording to  their  purpose.  The  object  of 
all  is  to  procure  great  heat,  directly  ap- 
plicable to  the  purpose. 

Iron  furnaces  consist  of ,a  cone  20  or  30 
feeVdeep,  to  receive  the  ore,  the  flux,  and 
the  coke  or  fuel,  in  layers,  with  an  ash 
grate  beneath,  and  blasting  bellows  to  in- 
crease the  supply  of  oxygen.  They  are 
many  weeks  in  preparation,  so  as  to  ac- 
quire a  high  degree  of  heat,  and  then  they 


are  never  suffered  to  cool,  but  constantly 
supplied  with  ore,  flux,  and  fuel. 

A  gas  furnace  is  so  built  that  the  fire 
and  flame  surround  the  retorts  full  of 
coal,  and  keep  them  at  a  white  heat. 

A  chemical  furnace  is  more  various  in 
its  uses,  and  should  be  built  with  a  table- 
top,  and  horizontal  flue  covered  with 
plate  iron,  over  which  should  be  sand 
baths,  and  other  receptacles,  with  hoods 
and  covers. 

The  air-furnace,  for  melting,  has  an 
ashes  hole,  and  a  lateral  hole  near  the 
bottom  of  the  grate.  The  fire-place  is 
inclosed,  and  fuel  put  in  at  the  top,  so  as 
to  surround  the  covered  crucibles  or  cucu- 
bets  placed  in  the  fire.  The  exit  of  smoke, 
&c,  is  at  the  side,  in  a  horizontal  flue. 

A  reverberators  furnace  is  one  closed  at 
the  top,  or  with  a  reverberating  dome 
with  a  fire  beneath,  and  a  perpendicular 
flue  through  the  dome.  At  the  side  is 
an  orifice  for  the  neck  of  any  retort 
placed  in  the  body. 

There  are  various  patent  and  special 
varieties  of  furnaces,  but  the  same  gene- 
ral forms  pervade  them.  Charcoal,  or 
coke,  or  ashes,  produce  the  highest  heat, 
but  coals  are  used  in  glass-houses,  distil- 
leries, and  breweries. 

Accuni's  Lamp  Furnace  is  very  conve- 
nient and  powerful  for  operations  in  the 
small  way.  In  the  burning  part  it  is  Ar- 
gand's  lamp,  but,  on  the  upright  stan- 
dard, three  or  four  arms  slide  with  rings 
at  their  ends,  to  raise  higher  and  lower, 
and  fix  with  nuts  and  screws,  adapted  t& 
receive  retorts,  alembics,  flasks,  ac,  for 
distillations,  digestions,  &c.  In  some,  a 
second  cylinder  and  second  flame  is  made, 
by  which  the  heat  is  trebled,  and  most 
processes  performed  in  a  small  way,  with- 
out a  furnace. 

The  furnace  of  the  Royal  Institution  is 
of  brick -work,  52  inches  by  30.  The  iron 
plate  and  sand-baths,  57  by  42.  It  is  34 
inches  high. 

A  very  powerful  furnace,  equal  to  any 
purpose,  has  been  made  at  the  Royal  In- 
stitution, by  cutting  the  bottom  off  a  blue 
pot,  and  fixing  it  tight  in  a  larger  one,  18 
by  13  inches ;  then,  through  a  single  hole 
in  the  bottom  of  the  outer  pot,  blowing 
with  a  pair  of  double  bellows.  It  melts 
pure  iron  in  a  quarter  of  an  hour,  renders 
platinum  soft,  and  fuses  rhodium.  The 
fuel  is  coke,  and  it  disappears,  leaving 
scarcely  slag  ;  proving  the  superiority  of 
the  blast  furnace  over  all  others. 

Faraday  states,  that  a  pint  of  water  may 
be  boiled  in  a  cartridge-paper  vessel, 
placed  over  a  chemical  lamp. 


>] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


195 


Mr.  Nott  haa  taken  out  a  patent  for  a 
mode  of  giving  to  furnaces  a  circular  or 
semicircular  form,  that  the  fresh  coals, 
when  the  fire  receives  a  supply  of  them, 
may  be,  by  turning  the  furnaces  on 
pivots,  by  which  it  is  supported,  brought 
mto  a  position  with  reference  to  the  coals 
already  ignited,  that  the  gaseous  products 
of  the  fresh  coals  shall  pass  through  the 
ignited  portion,  that  the  combustible  part 
may  be  consumed  ;  and  thus  etfect  a  sav- 
ing of  fuel,  and  the  prevention  of  much 
of  the  nuisance  arising  from  the  escape  of 
uneonsumed  smoke.  This  rotating,  or 
rather  vibrating  furnace,  is  of  course  to 
be  provided  with  an  iron  casing,  to  sur- 
round the  sides  of  the  furnace  not  in- 
tended to  be  exposed. 

By  Witty' s  improved  furnace,  fresh 
coal  is  first  carbonized,  that  is,  the  gas 
is  separated  from  it  and  inflamed,  leaving 
only  coke,  which,  being  slowly  pushed 
forward,  supplies  the  coke  fire  ;  and  the 
combusion  or  burning  of  the  coke  pro- 
duces heat  enough  to  carbonize  the  coal, 
and  air  enough  to  inflame  the  gas  ;  con- 
sequently, coal,  instead  of  being  burned 
in  its  usual-  crude  state,  is  subjected  to 
two  distinct  processes,  viz.  carbonization, 
and  then  combustion ;  for,  by  this  con- 
trivance, he  burns  the  gas  and  the  coke 
together. 

The  vent  of  a  furnace  has  given  rise  to 
much  difference  of  opinion  as  to  the  size 
it  ought  to  have.  Some  make  it  large,  to 
allow  a  freer  passage  for  the  burnt  air 
into  the  chimney ;  others  again,  small, 
that  the  heat  may  not  be  dissipated  and 
carried  up  into  the  chimney  in  waste.  It 
is  generally  a  single  opening,  but,  in  por- 
celain furnaces,  the  manufacturers  use  a 
number  of  small  openings,  instead  of  a 
single  vent,  with  the  view  of  assisting  in 
the  equal  distribution  of  the  heat  through- 
out all  parts  of  the  chamber,  and  this 
practice  should  be  adopted  whenever 
this  equal  distribution  is  requisite.  These 
artists  are  also  careful  that  the  sum  of 
the  areas  of  these  holes  should  be  exactly 
equal  to  that  of  the  throats  by  which  the 
flame  and  heated  air  enters  into  the  cham- 
ber. It  seems,  therefore,  advisable,  in 
all  cases,  to  make  the  vent  or  vents  equal 
in  area  to  that  of  the  free  space  left  be- 
tween the  bars  of  the  grate.  Mr.  Losh 
proposed  to  remove  the  vent  to  the  front 
of  the  furnace,  immediately  over  the  feed- 
ing or  stoking-door,  and  to  conduct  the 
burned  air,  through  channels  made  in 
the  masonry,  into  the  flue  of  the  chim- 
ney. A  great  advantage  attends  this 
construction,  that,  when  either  of  the  en- 


trances into  the  fire-room  are  opened,  the 
indraught  of  air,  instead  of  rushing  over 
the  surface  of  the  burning  fuel,  and 
striking  against  the  vessels  and  mate- 
rials, instantly  passes  up  the  vent,  and 
does  not  enter  at  all  into  the  interior  of 
the  furnace,  whence  this  is  much  less 
cooler  than  in  the  furnaces  of  the  usual 
construction. 

The  chimney,  or  flue,  is  one  of  the 
most  important  parts  of  a  furnace  ;  and 
yet,  in  general,  the  least  attended  unto  ; 
being  usually  made  much  too  large  in  its 
horizontal  area.  By  making  it  thus 
large,  the  draught  through  it  is  much 
diminished,  and"  the  soot  collects  and  be- 
comes troublesome.  For,  when  the  sides 
of  the  flue  contain  a  larger  surface  than 
can  be  duly  heated,  the  necessary  rarefac- 
tion of  the  air  passing  through  it  is  de- 
stroyed. On  this  principle,  alone,  the 
draught  of  chimneys  depends  ;  and  the 
cavity  being  too  large  proportionably  to 
the  current  of  air,  the  force  of  it  is  so 
diminished  that  the  soot,  instead  of  being 
blown  out,  gathers  and  rests  on  the  sides 
till  it  obstructs  the  passage,  and  choking 
up  the  draught  deadens  the  fire,  espe- 
cially at  the  first  lighting  of  it,  by  which 
means  the  progress  of  the  operation  is 
sometimes  greatly  retarded.  Instead, 
therefore,  of  the  large  proportion  now 
made  use  of,  if  the  chimney  be  intended 
for  the  use  of  one  furnace  only,  an  area 
equal  to  that  of  the  free  space  between 
the  bars  of  the  grate  is  fully  sufficient ; 
and  this  may  be  increased  in  proportion, 
where  it  is'designed  for  a  greater  num- 
ber. 

The  calculations  of  Tredgold  show  that 
each  side  of  a  chimney  having  a  square 
basis,  or  the  narrowest  side,  if  the  basis 
be  rectangular,  should  be,  at  the  least, 
one  foot  in  breadth  for  every  10  feet  in 
height ;  and  the  area  of  the  flue  ought 
not  to  exceed  one-third  of  the  area  of  the 
chimney. 

The  wall  of  chimneys  is  usually  single, 
but  when  the  air  which  passes  up  the 
flue  is  very  hot,  it  has  been  found  pre- 
ferable to  have  the  wall  double,  with  an 
empty  space  left  between  the  two,  which 
are  tied  together  from  space  to  space,  by 
bricks  passing  from  one  to  the  other. 

FUENACF.  (Russian.)  A  kind  of 
furnace  adapted  for  burning  wood,  and 
used  much  in  the  villages  and  rural  dis- 
tricts in  New  England.  It  consumes  less 
wood  than  a  stove,  and  requires  but  little 
care,  preserving  an  agreeable  and  equal 
temperature  in  the  room,  as  it  presents  a 
greater  amount  of  heated  surface  than  « 


196 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[fus 


stove,  and  does  not  require  to  be  so  in- 
tensely heated  up. 

The  annexed 
cut  represents 
this  furnace  in  a 
transverse  sec- 
tion. A  is  the  fire 
place,  to  which  an 
iron  door  is  fixed. 
C  is  the  brick- 
work ;  D  a  soap- 
stone  cap  ;  1  2  3 
4  are  flues  in  con- 
nexion with  each 
other,  and  1  being 
in  connexion  with 
A  ;  to  4,  a  fun- 
nel connecting  the 
flue  with  the 
chimney  is  fixed,  which  has  a  damper 
attached.  The  furnace  should  stand  out 
a  few  inches  from  the  chimney,  so  as  to 
save  the  heat  from  all  sides. 

The  fire  place  is  filled  with  wood,  and 
the  dampers  opened  till  the  wood  gets 
well  on  fire.  The  dampers  are  then  closed 
perfectly  tight,  though  not  so  suddenly 
as  to  make  it  smoke.  It  will  want  no 
more  attention  till  the  wood  is  nearly 
gone,  when  it  can  be  replenished  and  im- 
mediately shut  up  if  there  are  plenty  of 
coals.  It  never  need  be  opened  more 
than  three  times  a  day  in  coldest  weather, 
morning,  noon,  and  night,  and  in  more 
moderate  weather  not  more  than  once  or 
twice.    The  draught  is  generally  good. 

A  common  form  is  about  three  feet  in 
length,  sixteen  inches  wide,  two  and  a 
half  feet  high — though  the  size  should 
depend  upon  the  size  of  the  room.  They 
may  be  built  upon  the  floor  by  having 
a  sufficient  thickness  of  brick  between  the 
floor  and  fire.  The  cost  of  one  made  all 
of  brick,  is  not  over  four  dollars,  (pressed 
brick).  A  new  furnace  must  be  dry  be- 
fore it  is  used. 

FURNACE  (Salter's).  Mr.  Salter, 
of  New  Jersey,  has  taken  out  a  patent  for 
his  improved  furnace,  which  is  adapted 
to  ores,  yielding  40  percent,  and  upwards 
of  iron.  *  It  consists  of  a  triple  chambered 
furnace,  one  above  the  other — the  ore 
being  pulverized  and  mixed  with  hard 
coal,  and  ground  fine,  is  placed  in  the 
upper  chamber — where  the  gases  and 
impurities,  such  as  sulphur,  &c,  are 
carried  off  at  low  temperature.  From 
thence  it  is  drawn  through  openings  in 
the  bottom,  into  the  second  or  middle 
chamber,  where  the  fluxing  materials  are 
added — thence  it  is  drawn  down  openings 
to  the  lower  or  puddling  chamber — the 


whole  process   occupying  less  than  an 
hour  and  a  half. 

Five  men  are  required  each  turn  to 
work  the  furnace,  and  the  yield  is  about 
400  lbs.  per  hour  and  a  half.  Two  and  a 
half  tons  coal  are  consumed  in  24  hours. 
The  cost  of  the  iron  wDl  vary  according  to 
the  facilities  forgetting  the'ore  and  coal, 
the  cost  of  labor,  &c.  Former  experi- 
ments have  proved,  as  far  as  they  have 
been  made,  that  anthracite  coal  does  bet- 
ter as  the  deoxidizing  material  than  bitu- 
minous coal,  and  quite  as  well  as  char- 
coal, but  the  bituminous  coal  is  quite  as 
good  (though  no  better)  as  either  for  fuel 
to  heat  the  ores. 

It  is  stated  that  iron  of  the  first  quality 
can  be  made  by  it  at  Newark,  and  sold  in 
New-York  at  $25  per  ton. 

FUSEE.  In  watch-work,  that  part  of 
the  machinery  about  which  the  chain  is 
wound,  and  which  is  immediately  acted 
upon  by  the  mainspring.  The  use  of  the 
fusee  is  to  equalize  the 
action  of  the  spring. 
In  proportion  as  the 
spring  becomes  un- 
wound, its  effort  con- 
tinually relaxes.;,  so 
that  if  the  first  wheel 
were  attached  to  the  barrel,  as  is  often 
the  case  in  common  watches,  the  in- 
equality of  the  impelling  power  would 
produce  a  corresponding  inequality  in 
the  rate  of  going.  In  order  to  correct 
this,  one  end  of  the  chain  is  attached  to 
and  wound  round  the  barrel  in  which  the 
main-spring  is  contained ;  while  the 
other  end  is  coiled  about  the  fusee,  which 
has  a  conical  shape,  and  is  fixed  on  the 
axis  of  the  first  wheel.  The  principle 
generally  adopted  for  determining  the 
figure  of  the  fusee  is,  that  its  radius,  at 
any  point  to  which  the  chain  is  a  tangent, 
should  be  inversely  as  the  tension  of  the 
chain  in  that  position.  Within  certain 
limits  this  is  true  ;  and  if  we  assume  with 
Hooke,  that  the  force  of  a  spring  is  pro- 

Sortional  to  the  distance  to  which  it  is 
rawn  from  the  position  of  rest,  and  also 
lay  aside  all  consideration  of  the  length 
of  the  chain  wrapped  about  the  fusee,  it 
would  be  easy  to  show  that  the  fusee 
should  be  the  solid  generated  by  the  re- 
volution of  the  equilateral  hyperbola 
about  its  asymptote.  This  conclusion  is, 
however,  by  no  means  correct;  but 
though  the  subject  has  been  treated  by 
several  eminent  mathematicians,  very 
little  practical  advantage  has  been  de- 
rived from  the  theoretical  investigations. 
In  fact,  a  moderate  approximation  to  the 


gag] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


197 


true  figure  (whatever  that  may  be)  is  all 
that  can  be  attained  in  practice,  and  all 
that  is  necessary. 

FUSIBILITY.  That  property  by  which 
solids  assume  the  fluid  state. 

Some  chemists  have  asserted  that  fu- 
sion is  simply  a  solution  in  caloric ;  but 
this  opinion  includes  too  many  yet  unde- 
cided questions,  to  be  hastily  adopted. 

Fusibility  of  Metals,  as    given,  by  M. 
Thenard. 

1.  Fusible  below  a  red  heat. 

CentigT. 

Mercury  —39° 

Potassium  -f-5S 
Sodium  90 

Tin  210 

Bismuth  256 

Lead  260 

Tellurium  Less  fusible  than  lead. 

Arsenic  Undetermined. 

Zinc  370^ 

Antimony  A  little  below  a  red  heat 
Cadmium 

2.  Infusible  below  a  red  heat. 


Silver 

Copper 

Gold 

Cobalt 


Pyrometer  of  Wedgewood. 
20 

27 


|  A  little  less  difficult  to  melt 

than  iron. 
(130 
(158 

160 

As  manganese. 

Nearly  infusible ;  and  to  be 
obtained  at  a  forge  heat 
only  in  small  buttons. 


Infusible  at  the  forge  fur- 
nace. Fusible  at  the  oxy- 
hydrogen  blowpipe. 


Iron 

Manganese 

Nickel 

Palladium 

Molybdenum 

Uranium 

Tungsten 

Chromium 

Titanium 

Cerium 

Osmium 

Iridium 

Khodiun 

Platinun. 

Columbium 


FUSIBLE  METAL.    See  Alloy. 

FUSTET.  The  wood  of  the  rhus  eoti- 
nus,  a  fugitive  yellow  dye. 

FUSTIAN  is  a  species  of  coarse  thick 
twceled  cotton,  and  is  generally  dyed  of 
olive,  leaden,  or  other  dark  color.  Be- 
sides the  common  fustian,  which  is  known 
by  the  name  of  pillow  (probably  pilaw), 
the  cotton  stuffs  called  corduroy,  vel- 
verett,  velveteen,  thicksett,  used  for 
men's  wearing  apparel,  belong  to  the  same 
fabric.  The  commonest  kind  is  mere- 
ly a  tweed  of  four,  or  sometimes  five 
leaves,  of  a  very  close  stout  texture,  and 
very  narrow,  seldom  exceeding  17  or  18 
inches  in  breadth.  It  is  cut  from  the  loom 
in  half  pieces,  or  ends,  as  they  are  usually 


termed,  about  35  yards  long,  and  after 
undergoing  the  subsequent  operations  of 
dyeing,  dressing,  and  folding,  is  ready  for 
the  market. 

FUSTIC.  The  old  fustic  of  the  English 
dyer,  as  the  article  fustet  is  their  yellow 
fustic.  It  is  the  wood  of  the  Morus  tinc- 
toria.  It  is  light,  not  hard,  and  pale  yel- 
low with  orange  veins ;  it  contains  two 
coloring  matters,  one  resinous,  and  an- 
other soluble  in  water.  The  latter  resem- 
bles weld,  but  it  has  more  of  an  orange 
cast,  and  is  not  so  lively. 

Its  decoctions  in  water  are  brightened 
by  the  addition  of  a  little  glue,  and  more 
by  curdled  milk.  This  wood  is  rich  in 
color,  and  imparts  permanent  dyes  to 
woollen  stuffs,  when  aided  by  proper 
mordants.  It  unites  well  with* the  b;ue 
of  the  indigo  vat,  and  Saxon  blue,  in  pro- 
ducing green  of  various  shades.  Alum, 
tartar,  and  solution  of  tin,  render  its 
color  more  vivid  ;  sea  salt  and  sulphate 
of  iron  deepen  its  hue.  From  five  to  six 
parts  of  old  fustic  are  sufficient  to  give  a 
lemon  color  to  sixteen  parts  of  cloth.  The 
color  of  weld  is  however  purer  and  less 
inclined  to  orange ;  but  that  of  fustic  is 
less  affected  by  acids  than  any  other  yel- 
low dye.  This  wood  is  often  employed 
with  Sulphate  of  iron  in  producing  olive 
and  brownish  tints,  which  agree  well 
with  its  dull  yellow.  For  the  same  rea- 
son it  is  much  used  for  dark  greens. 

GADOLIN1TE  or  YTTEKITE,  is  a 
mineral  black,  brownish,  or  yellow  color, 
granular  or  compact,  vitreous  and  conch oi- 
dal  in  fracture;  of  spec.  grav.  4*23.  It 
readily  scratches  glass,  and  melts  before 
the  blow-pipe  into  an  opaque  glass,  and 
sometimes  with  intumescence.  It  affords, 
with  acids,  a  solution  which  gives  with 
soda  a  precipitate  partly  soluble  in  car- 
bonate of  ammonia.  It  contains  nearly  50 
per  cent,  of  the  earth  yttria.  Its  remain- 
ing constituents  are  silica,  25*8,  oxide  of 
cerium  17-92,  oxide  of  iron  11-43.  This 
mineral  is  rare,  found  at  Fahlun  and 
Ytterly  in  Sweden,  and  also  in  the  south 
of  Ireland.  Its  peculiar  constituent  was 
discovered  by  Dr.  Gadoline,  hence  the 
name. 

GAGE  or  GAUGE.  In  architecture, 
the  length  of  a  slate  or  tile  below  the  lap ; 
also  the  measure  to  which  any  substance 
is  confined.  Plasterers  use  the  word  to 
signify  the  greater  or  less  quantity  of 
piaster  of  Paris  used  with  the  common 
plaster  to  accelerate  its  setting. 

Gage.  In  physics,  an  instrument  or 
apparatus  for  measuring  the  state  of  a 
phenomenon.     Gage  qf"the  air  purryp  is 


198 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[GAL 


merely  a  barometer  communicating  with 
the  inside  of  the  receiver,  which  marks, 
in  the  usual  manner,  the  pressure  of  the 
air  within  the  receiver  by  the  height  of 
the  equiponderant  column  of  mercury, 
and  consequently  shows  the  degree  to 
which  the  air  is  rarefied.  A  short  ba- 
rometer may  be  employed  for  this  pur- 
pose ;  but  in  this  case  it  will  not  be  aftect- 
ed  till  the  rarefaction  of  the  air  has  been 
carried  so  far  as  to  correspond  with  the 
length  of  the  tube.  An  instrument  for 
the  same  purpose,  but  on  a  different 
principle,  was  invented  by  Smeaton,  and 
trom  its  form  called  a  pear-gage.  It  is  a 
vessel  suspended  in  the  receiver,  and  ex- 
hausted to  the  same  degree ;  but  when 
the  rarefaction  i«  carried  as  far  as  intend- 
ed, the  open  orifice  of  the  gage  is  let 
down  into  a  vessel  containing  mercury, 
which,  on  the  readmission  of  the  air,  is 
forced  up  into  the  pear,  and  the  degree 
of  rarefaction  is  judged  of  by  the  quan- 
tity of  mercury  introduced.  The  idea  is 
ingenious  ;  but  the  indications  given  by 
this  instrument  are  not  correct.  For 
wind-gage,  see  Anemometer  ;  water-gage, 
Bee  Hydrometer. 

GALENA.  .  Sulphuret  of  lead,  found 
massive  and  in  cubic  crystals.  Color  is 
blue  gray,  like  lead,  but  brighter ;  lustre, 
metallic ;  breaking  into  cubic  fragments, 
soft  but  brittle.  Spec.  grav.  7-22  to  7-58  ; 
it  effervesces  with  nitric  and  hydrochloric 
acids,  and  contains  from  45  to  83  per  cent, 
of  lead,  and  from  56  to  16  of  sulphur. 
It  also  contains  some  silver  and  occasion- 
ally antimony,  zinc,  iron  and  bismuth.  Be- 
fore the  blow-pipe  it  decrepitates,  and  is 
decomposed  and  melted  on  the  charcoal, 
yielding  a  button  of  metallic  lead.  Some- 
times as  much  as  100  oz.  of  silver  will  be 
found  in  a  ton  of  ore ;  it  is  then  worked 
as  a  silver  ore,  and  called  argentiferous 
galena.  The  varieties  which  contain  most 
silver  are  not  the  most  lustrous,  being 
sometimes  black-gray ;  occasionally  ga- 
lena is  mixed  with  silex  and  lime,  and 
only  yields  50  per  cent,  of  lead.  Sulphu- 
ret of  lead  occurs  in  primitive  and  meta- 
morphic  beds,  but  more  frequently  in 
the  upper  secondary,  especially  in  the 
compact  blue  limestone  alternating  with 
fossiliferous  beds  ;  occasionally  it  is  found 
in  beds  of  coal,  and  bitumen  is  rarely 
found  in  its  veins.  Galena  is  abundant 
in  Great  Britain,  and  widely  dispersed 
over  this  country.  The  mines  of  Missouri 
are  very  rich  and  extensive,  and  still  more 
bo  those  extending  through  Illinois,  Iowa, 
and  Wisconsin,  of  which  Galena  is  the 
centre.    This  lead  region  embraces  about 


three  thousand  square  miles  in  the  S.  E. 
of  Iowa,  extending  across  the  Mississippi 
into  Wisconsin  and  Illinois.  Most  of  the 
metallic  lead  is  obtained  from  galena, 
and  contains  a  little  silver.    (See  Lead.) 

GALL  OF  ANIMALS,  or  OX-GALL, 
purification  of.  Painters  in  water  colors, 
scourers  of  cloth,  and  many  others,  em- 
ploy ox-gall  or  bile ;  but  when  it  is  not  puri- 
fied, it  is  apt  to  do  harm  from  the  green- 
ness of  its  own  tint.  It  becomes  therefore 
an  important  object  to  clarify  it,  and  to 
make  it  limpid  and  transparent  like  wa- 
ter. The  following  process  has  been 
given  for  that  purpose.  Take  the  gall  of 
newly  killed  oxen,  and  after  allowing  it  to 
settle  for  12  or  15  hours  in  a  basin,  pour 
the  supernatant  liquor  off  the  sediment 
into  an  evaporating  dish  of  stone  ware, 
and  expose  it  to  a  boiling  heat  in  a  water 
bath,  till  it  is  somewhat  thick.  Then 
spread  it  upon  a  dish,  and  place  it  before 
a  fire  till  it  becomes  nearly  dry.  In  this 
state  it  may  be  kept  for  years  in  jelly  pots 
covered  with  paper,  without  undergoing 
any  alteration.  When  it  is  to  be  used,  a 
piece  the  size  of  a  pea  is  to  be  dissolved 
in  a  tablespoonful  ot  water. 

Another  and  probably  a  better  mode  of 
purifying  ox-gall  is  the  following.  To  a 
pint  of  the  gall  boiled  and  skimmed,  add 
an  ounce  of  fine  alum  in  powder,  and 
leave  the  mixture  on  the  fire  till  the  alum 
be  dissolved.  When  cool,  pour  into  a 
bottle,  which  is  to  be  loosely  corked. 
Now  take  a  like  quantity  of  gall,  also 
boiled  and  skimmed,  add  an  ounce  of 
common  salt  to  it,  and  dissolve  with  heat ; 

f)ut  it  when  cold  into  a  bottle,  which  is 
ikewise  to  be  loosely  corked.  Either  of 
these  preparations  may  be  kept  for  several 
years  without  their  emitting  a  bad  smell. 
After  remaining  three  months,  at  a  mode- 
rate temperature,  they  deposit  a  thick 
sediment  and  become  clearer,  and  fit  for 
ordinary  uses,  but  not  for  artists  in  water 
colors  and  miniatures,  on  account  of  their 
yellowish-green  color.  To  obviate  this 
inconvenience,  each  of  the  above  liquors 
is  to  be  decanted  apart,  after  they  have 
become  perfectly  settled,  and  the  clear 
portion  of  both  mixed  together  in  equal 
parts.  The  yellow  coloring  matter  still 
retained  by  the  mixture  coagulates  im- 
mediately and  precipitates,  leaving  the 
ox-gall  perfectly  purified  and  colorless. 
If  wished  to  be  still  finer,  it  may  be  passed 
through  filtering  paper;  but  it  becomes 
clearer  with  age,  and  never  acquires  a 
disagreeable  smell,  nor  loses  any  of  its 
good  qualities. 
Clarified  ox-gall  combines  readily  with 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


199 


coloring  matters  or  pigments,  and  gives 
them  solidity  either  by  being  mixed  with 
or  passed  over  them  upon  paper.  It  in- 
creases the  brilliancy  and  the  durability 
of  ultramarine,  carmine,  green,  and  in 
general  of  all  delicate  colors,  whilst  it 
contributes  to  make  them  spread  more 
evenly  upon  the  paper,  ivory,  &c.  When 
mixed  with  gum-arabic,  it  thickens  the 
colors  without  communicating  to  them  a 
disagreeable  glistering  appearance ;  it 
prevents  the  gum  from  cracking,  and 
fixes  the  colors  so  well  that  others  may  be 
applied  over  them  without  degradation. 
Along  with  lamp-black  and  gum,  it  forms 
a  good  imitation  of  China  ink.  When  a 
coat  of  ox-gall  is  put  upon  drawings  made 
with  black  lead  or  crayons,  the  lines  can 
be  no  longer  effaced,  but  may  be  painted 
over  safely  with  a  variety  of  colors  pre- 
viously mixed  up  with  the  same  ox- 
gall. 

Miniature  painters  find  a  great  ad- 
vantage in  employing  it;  by  passing  it 
over  ivory  it  removes  completely  the 
unctuous  matter  from  its  surface ;  and 
when  ground  with  the  colors,  it  makes 
them  spread  with  the  greatest  ease,  and 
renders  them  fast. 

It  serves  also  for  transparencies.  It  is 
first  passed  over  the  varnished  or  oiled 
paper,  and  is  allowed  to  dry.  The  colors 
mixed  with  the  gall  are  then  applied,  and 
cannot  afterwards  be  removed  by  any 
means. 

It  is  adapted  finally  for  taking  out  spots 
of  grease  or  oil. 

GALL  OF  GLASS.  The  salts  and 
other  impurities  which  float  upon  the 
fused  materials  for  the  manufacture  of 
glass,  and  which  is  skimmed  off.  It  is 
also  called  sandlver. 

GALLON.  An  English  measure  of 
capacity.  By  act  of  parliament  the  impe- 
rial gallon  is  to  contain  10  lbs.  avoirdu- 
pois "of  distilled  water,  weighed  at  the 
temperature  of  62°  of  Fahrenheit,  and 
the  barometer  standing  at  30  inches. 
This  is  equivalent  to  277 '274  cubic  inches. 
The  old  English  gallon,  wine  measure, 
contained  231  cubic  inches ;  beer  mea- 
sure, 282  cubic  inches. 

GALLIC  ACID.  (See  G  all-Nuts)  It 
is  composed  of  7  atoms  of  carbon,  3  atoms 
of  hydrogen,  and  5  atoms  of  oxygen. 

GALL-NUTS.  Excrescences  produced 
by  the  cynips,  a  small  insect  which  depo- 
sits its  eggs  in  the  tender  shoots  of  the 
Quercus  in/f ectopia,  a  species  of  oak  abun- 
dant in  Asia  Minor.  When  the  maggot 
is  hatched  it  produces  a  morbid  excres- 
cence of  the  surrounding  parts,  and  ulti- 


mately eats  its  way  out  of  the  nidus  thus 
formed.  The  best  galls  are  imported 
from  Aleppo  and  Smyrna ;  their  princi- 

?al  ingredients  are  tan  and  gallic  acid, 
lie  infusion  of  galls  affords  a  dense 
white  precipitate  in  solution  of  jolly,  and 
a  black  precipitate  with  the  persalts  of 
iron.  The  latter  property  leads  to  the 
use  of  galls  in  the  manufacture  of  ink  and 
black  dye  ;  they  are  also  used  as  an  as- 
tringent in  medicine. 

Galls  consist  principally  of  three  sub- 
stances ;  tannin  or  tannic  acid ;  yellow 
extractive  ;  and  gallic  acid.  Their  decoc- 
tion has  a  very  astringent  and  unpleasant 
bitter  taste.  The  following  are  their  ha- 
bitudes with  various  re-agents  : — 

Litmus  paper  is  powerfully  reddened. 

Proto-chloride  ot  tin  produces  an  Isa- 
bel-yellow precipitate. 

Alum  ;  a  yellowish  gray  precipitate. 

Acetate  of  lead ;  a  thick  yellowish 
white  precipitate. 

Acetate  of  copper ;  a  chocolate  brown 
precipitate. 

Ferric  sulphate  (red  sulphate  of  iron); 
a  blue  precipitate. 

Sulphuric  acid;  a  dirty  yellowish  pre- 
cipitate. 

Acetic  acid  brightens  the  muddy  de- 
coction. 

The  galls  of  the  Q-uercus  Cerris  and 
common  oak  are  of  a  brown  color,  prickly 
on  the  surface,  and  irregular  in  shape 
and  size.  They  are  used  chiefly  for  tan- 
nine: in  Hungary,  Dalmatia,  and  the 
southern  provinces  of  the  Austrian 
states,  where  they  abound. 

Tannin  or  tannic  acid  is  prepared  as 
follows  : — Into  a  long  narrow  glass  adopt- 
er tube,  shut  at  its  lower  orifice  with  a 
cotton  wick,  a  quantity  of  pounded  galls 
are  put,  and  slightly  pressed  down.  The 
tapering  end  of  the  tube  being  inserted 
into  a  matrass  or  bottle,  the  vacant  upper 
half  of  the  tube  is  filled  with  sulphuric 
ether,  and  then  closed  with  a  ground- 
glass  stopper.  Next  day  there  will  be 
found  in  the  bottle  in  two  distinct  strata, 
of  which  the  more  limpid  occupies  the 
upper  part,  and  the  other,  of  a  sirupy 
consistence  and  amber  color,  the  lower. 
More  ether  must  be  filtered  through  the 
galls,  till  the  thicker  liquid  ceases  to  aug- 
ment. Both  are  now  poured  into  a  fun- 
nel, closed  with  the  finger,  and  after  the 
dense  liquor  is  settled  at  the  bottom,  it  is 
steadily  run  off  into  a  capsule.  This,  af- 
ter being  washed  repeatedly  with  ether, 
is  to  be  transferred  into  a  stove  chamber, 
or  placed  under  the  receiver  of  an  air- 
pump,  to  be  evaporated.    The  residuary 


200 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gai 


matter  swells  up  in  a  spongy  crystalline 
form  of  considerable  brilliancy,  some- 
times colorless,  but  more  frequently  of  a 
faintly  yellowish  hue. 

This  is  pure  tannin,  which  exists  in 
galls  to  the  amount  of  from  40  to  45  per 
cent.  It  is  indispensable  that  the  ether 
employed  in  the  preceding  process  be 
previously  agitated  with  water,  or  that  it 
contain  some  water,  because  by  using 
anhydrous  ether,  not  a  particle  of  tannin 
will  be  obtained. 

Tannic  acid  is  a  white  or  yellowish  so- 
lid, inodorous,  extremely  astringent,  very 
soluble  in  water  and  alcohol,  much  less 
so  in  sulphuric  ether,  and  uncrystalliza- 
ble.  Its  watery  solution,  out  of  contact 
of  air,  undergoes  no  change  ;  but  if,  in  a 
very  dilute  state,  it  be  left  exposed  to  the 
atmosphere,  it  loses  gradually  its  trans- 
parency, and  lets  fall  a  slightly  grayish 
crystalline  matter,  consisting  almost  en- 
tirely of  gallic  acid.  For  procuring  this 
acid  in  a  perfectly  pure  state,  it  is  merely 
necessary  to  treat  that  solution  thus 
changed  with  animal  charcoal,  and  to  fil- 
ter it,  in  a  boiling  state,  through  paper 
previously  washed  with  diluteinuriatic 
acid.  The  gallic  acid  will  fall  down  in 
crystals  as  the  liquid  cools. 

Gallic  acid  is  always  produced  when 
any  substance  containing  tannic  acid  is 
exposed  to  the  air. 

Tannin  or  tannic  acid  consists  of  car- 
bon 51*56;  hydrogen  4*20 ;  oxygen  44*24. 

Gallic  acid  does  not  exist  ready  formed 
in  gallnuts,  but  that  is  produced  by  the 
reaction  of  atmospheric  oxygen  upon  the 
tannin  of  these  concretions. 

Gallic  acid  is  a  solid,  feebly  acidulous 
and  styptic  to  the  taste,  inodorous,  crys- 
tallizing in  silky  needles  of  the  greatest 
whiteness  ;  soluble  in  about  100  times  its 
weight  of  cold,  and  in  a  much  smaller 
quantity  of  boiling  water;  more  soluble 
in  alcohol  than  in  water,  but  little  so  in 
sulphuric  ether. 

Gallic  acid  does  not  decompose  the 
salts  of  protoxyde  of  iron,  but  it  forms, 
with  the  sulphate  of  the  peroxyde,  a  dark 
blue  precipitate,  much  less  insoluble  than 
the  tannate  of  iron.  Gallic  acid  takes  the 
oxyde  from  the  acetate  and  nitrate  of 
lead,  and  throws  down  a  white  gallate 
unchangeable  in  the  air,  when  it  is  mixed 
with  that  acetate  and  nitrate.  It  occa- 
sions no  precipitate  in  solutions  of  gela- 
tine (isinglass  or  glue),  by  which  its 
freedom  from  tannin  is  verified. 

GALVANIZED  IKON  is  the  some- 
what fantastic  name  newly  given  to  iron 
tinned    by    a   peculiar    patent    process, 


whereby  it  resists  the  rusting  influence 
of  damp  air,  and  even  moisture,  much 
longer  than  ordinary  tin  plate.  The  fol- 
lowing is  the  prescribed  process.  Clean 
the  surface  of  the  iron  perfectly  by  the 
joint  action  of  dilute  acid  and  friction, 
plunge  it  into  a  bath  of  melted  zinc,  and 
stir  it  about  till  it  be  alloyed  superficially 
with  this  metal ;  then  take  it  out,  and 
immerse  it  in  a  bath  of  tin,  such  as  is 
used  for  making  tin  plate.  The  tin 
forms  an  exterior  coat  of  alloy.  When 
the  metal  thus  prepared  is  exposed  to 
humidity,  the  zinc  is  said  to  oxydize 
slowly  by  a  galvanic  action,  and  to  pro- 
tect the  iron  from  rusting  within  it, 
whereby  the  outer  tinned  surface  remains 
for  a  long  period  perfectly  white,  in  cir- 
cumstances under  which  iron  tinned  in 
the  usual  way  would  have  been  superfi 
cially  browned  and  corroded  with  rust. 

GALVANISM.  (From  Galvani,  pro- 
fessor of  anatomy  at  Bologna,  the  disco- 
verer of  some  of  the  phenomona  copnect- 
ed  with  this  form  of  electricity  in  the  year 
1790.)  Under  this  term  are  frequently 
included  the  phenomena  of  Voltaic  elec- 
tricity (which  see).  We  shall  here  limit 
it  to  the  apparent  evolution  of  electricity 
by  the  contact  of  different  metals  ;  this  is 
best  observed  by  the  muscular  contrac- 
tions which  are  produced  in  the  leg  of  a 
frog  recently  killed,  when  two  different 
metals,  such  as  zinc  and  silver,  tin  and 
gold,  &c,  one  of  which  touches  the  cru- 
ral nerve,  and  the  other  the  muscles,  are 
brought  into  contact.  Every  time  the 
metals  touch  each  other  the  limb  be- 
come powerfully  convulsed  ;  and  if  the 
experiment  be  made  with  a  dead  rabbit, 
so  that  one  of  the  metals  be  in  contact 
with  the  brain,  and  the  other  with  the 
muscles  of  the  extremities,  the  whole 
body  of  the  animal  is  strangely  agitated. 
Similar  experiments  have  been  made  up- 
on the  bodies  of  criminals  shortly  after 
execution.  These  results,  which  have 
till  lately  been  considered  to  depend  up- 
on the  effects  of  electricity  excited  by  the 
contact  of  the  metals  upon  the  nervous 
and  muscular  systems,  led  Volta  to  his 
celebrated  researches,  which  terminated 
in  the  discovery  of  the  Voltaic  battery. 
Nearly  all  the  cases,  however,  of  the  ap- 

E  aren't  production  of  electricity  by  contact 
avebeen  satisfactorily  traced  by  Faraday 
to  chemical  action.  (See  Voltaic  Battery.) 
GALVANOMETER.  An  instrument 
for  ascertaining  the  presence  of  a  current 
of  electricity,  especially  Galvanic  or  Vol- 
taic electricity,  by  the  deviation  which  it 
occasions  in' the  magnetic  needle.    T*ie 


gal] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


201 


simplest  form  of  a  galvanometer  is  a  mag- 
netic needle  poised  upon  a  point,  and 
surrounded  by  one  or  more  coils  of  cop- 
per wire  covered  with  silk,  the  ends  a 
*  &  and  b  being  either  left 

O free,   or   terminating  in 

EEEIESEzEE)  tw0  8ma^    copper   cups 

I  containing  mercury,  for 

j^  the  convenience  of  com- 

munation  with  the  source  of  electricity. 

When  this  needle  is  placed  parallel  to  the 

coil,  and  in  the  magnetic  meridian  (as  re- 

S  resented  in  the  margin),  it  immediately 
eviates  when  the  electric  current  passes 
through  the  coil ;  and  the  deviation  is  ei- 
ther to  the  east  or  west,  according  to  the 
direction  of  the  current.  (See  Electro- 
Magnetism:.) 

GAMBOGE.  A  gum  resin,  concreted 
in  the  air  from  the  milky  juice  which  ex- 
udes from  several  trees.  The  gambogia 
gutta,  a  tree  which  grows  wild  upon 
the  coasts  of  Ceylon  and  Malabar,  pro- 
duces the  coarsest  kind  of  gamboge; 
the  guttaefera  -vera  (Stalagmites  cambogio- 
ides)  of  Ceylon  and  Siam  affords  the  best. 
It  comes  to  us  in  cylindrical  lumps,  which 
are  outwardly  brown  yellow,  but  reddish 
yellow  within,  as  also  in  cakes ;  it  is 
opaque,  easily  reducible  to  powder,  of 
specific  gravity  1*207,  scentless,  and  near- 
ly devoid  of  taste,  but  leaves  an  acrid 
feeling  in  the  throat.  Its  powder  and 
watery  emulsion  are  yellow. 

GANGUE.  A  term  to  denote  the  stony 
matter  which  fills  the  cavities  and  ac- 
companies the  ores  in  the  veins  of  metals. 

GAS.  When  solid  substances  are  ren- 
dered permanently  aeriform  by  heat,  the 
air  thus  produced  is  called  a  gas,  to  dis- 
tinguish it  from  those  substances  which 
turn  to  the  solid  or  fluid  states  when  the 
heat  is  abstracted. 

GAS  (Coal)  MANUFACTUKE  OF. 
The  separation  and  purification  of  the 
volatile  elastic  fluids  from  pit  coal,  which 
have  the  property  of  giving  out  light 
when  burned.  They  are  various  com- 
pounds of  carbon  and  hydrogen,  accom- 
}>anied  by  hydrogen  and  carbonic  oxide  in 
arge  quantity. 

The  application  of  the  gases  produced 
during  the  destructive  distillation  of  pit 
coal  to  the  purposes  of  illumination  is  a 
very  modern  invention.  But  the  germ 
of  it  may  be  traced  back  above  100  years ; 
for  the  first  mention  of  the  production  of  a 
permanently  elastic  and  inflammable  gas 
from  coal  occurs  in  the  Philosophical 
Transactions  for  1739,  in  which  there  is  a 
paper  by  the  Rev.  Dr.  Clayton,  describing 
a  method  of  filling  bladders  with  what  he 
9* 


calls  thespirit  of  coal,  obtainedby  distilling 
coal  in  a  retort  in  the  open  fire.'  He  says, 
"  I  filled  a  good  many  bladders  therewith, 
and  might"  have  filled  an  inconceivable 
number  more ;  for  the  spirit  continued  to 
rise  for  several  hours,  and  filled  the  blad- 
ders almost  as  fast  as  a  man  could  have 
blown  them  with  his  mouth,  and  yet  the 
quantity  of  coals  distilled  was  inconsidera- 
ble.  I  kept  this  spirit  in  the  bladders  a 
considerable  time,  and  endeavored  several 
ways  to  condense  it,  but  in  vain  ;   and 
when  I  had  a  mind  to  divert  strangers  or 
friends,  I  have  frequently  taken  one  of 
of  these  bladders    and  pricked  a  hole 
therein  with    a    pin,   and    compressing 
gently  the  bladder  near  the  flame  of  a 
candle  till  it  once  took  fire,  it  would  then 
continue  flaming  till  all  the  spirit  was  com- 
pressed out  of  the  bladder ;  which  waa 
the  more    surprising,   because   no    one 
eould  discern  any  difference  in  the  ap- 
pearance   between    these    bladders    and 
those  which  are  filled  with  common  air." 
Dr.  Clayton  seems  also  to  have  observed 
those    curious  phenomena   which  have 
lately  excited  so  much  attention  under 
the  terms  exosmose  and  endosmose  ;  for  he 
goes  on  to  say  that  he  found  "  that  this 
spirit  must  be  kept  in  good  thick  blad- 
ders, as  in  those  of  the  ox  or  the  like  ;  for 
if  I  filled  calves'  bladders  therewith,  it 
would  lose  its  inflammability  in  twenty- 
four  hours,  though  the  bladders  become 
not  relaxed  at  all.'' 

Dr.  Hales  (in  his  Vegetable  Statics)  and 
Dr.  Watson  (in  his  Chemical  Essays)  have 
each  alluded  to  the  properties  of  the  gas 
from  coal ;  but  it  was  not  until  the  end 
of  the  last  century  that  the  practicability 
of  substituting  coal  gas  for  other  inflam- 
mables, as  a  means  of  lighting  streets  and 
buildings,  became  an  object  of  attention. 
The  idea  of  applying  coal  gas  to  eco- 
nomical purposes  seems  first  to  have  oc- 
curred in  1792  to  Mr.  William  Murdoch, 
then  residing  at  Kedruth,  in  Cornwall. 
His  apparatus  consisted  of  an  iron  retort, 
with  tinned  _  copper  and  iron  tubes, 
through  which  the  gas  was  conducted  to 
a  considerable  distance ;  and  there,  as 
well  as  at  the  intermediate  points,  was 
burned  through  apertures  of  varied  forms 
and  dimensions ;  he  also  washed  the  gas 
with  water,  and  used  other  means  for  its 
purification.  In  1798  Mr.  Murdoch  con- 
structed a  larger  and  improved  apparatus 
for  the  purpose  of  lighting  Boulton  and 
Watt's  celebrated  manufactory  at  Soho, 
near  Birmingham,  which,  on  the  occasion 
of  the  peace  in  1802,  was  publicly  illumi- 
nated by  the  same  means. 


202 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gas 


In  all  extensive  and  well  conducted  es- 
tablishments, the  processes  for  the  man- 
ufacture of  gas  are  similar  and  uniform 
in  the  various  stages.  A  great  extent  of 
ground  is  occupied  with  the  retort  house, 

Kurifying  chambers,  and  space  for  the 
trge  gasometers.  The  arrangements 
are  similar  in  all.  They  are,  with 
slight  exceptions,  which  we  need  not  heed 
here,  as  follows  : — Each  side  of  the  retort 
house  has  a  succession  of  arched  recesses, 
each  eight  or  ten  feet  high,  six  or  seven 
wide,  and  about  as  many  in  depth.  These 
recesses,  when  bricked  or  otherwise 
closed  in  front,  form  ovens  or  furnaces, 
in  which  fuel  is  burnt  on  a  grate  at  the 
lower  part.  Five,  six,  eight,  or  more  ob- 
long iron  vessels,  each  holding  from  two 
to  three  bushels  of  cOals,  are  ranged  ho- 
rizontally in  this  oven,  from  front  to 
back,  so  that  the  heat,  flame,  and  smoke 
from  the  surface  may  play  around  them, 
and  make  them  red-not.  *  The  outer  end 
of  these  vessels,  which  are  the  retorts,  are 
left  opened  or  closed  as  occasion  may  re- 
quire ;  an  iron  door,  connected  with  a 
screw,  being  accurately  fitted  to  each  re- 
tort. The  retorts  are  semi-cylindrical  in 
shape,  with  the  flat  side  placed  lower- 
most. The  average  height  of  the  retorts 
is  perhaps  about  five  feet  from  the  ground ; 
under  them  is  a  fireplace,  through  which 
the  fuel  is  introduced  by  which  they  are 
heated  ;  and  under  this  again  is  a  kind 
of  ash-pit  or  shallow  vessel  into  which 
the  lime  water  is  poured  for  the  purpose 
of  evaporation.  The  operation  then  con- 
sists in  this  : — The  empty  retorts  are  first 
brought  to  a  red  heat ;  then  a  '  charge  of 
coals'  is  introduced ;  then  the  cover  is 
screwed  on  the  end,  and  made  air-tight 
by  a  cement  of  clay  and  lime.  Thus  the 
retorts  remain  for  about  five  hours,  dur- 
ing which  the  fireplace  is  opened  every 
hour  for  the  renewal  of  the  fuel  with 
which  the  retorts  are  heated ;  and  at 
the  end  of  this  time  all  the  gaseous  and 
vaporizable  matters  having  left  the  coal, 
and  passed  up  from  each  retort  by  a  pipe 
into  the  '  hydraulic  main,1  the  '  drawing 
of  the  retorts '  commences.  The  retort- 
cover  is  loosened  by  turning  a  screw  ;  a 
slight  explosion  takes  place  when  com- 
munication with  the  atmosphere  is  open- 
ed :  the  cover  is  removed  by  the  sooty 
and  almost  fire-proof  hands  of  the  men, 
and  the  coke  is  drawn  out  by  means  of 
rakes  eight  or  ten  feet  long.  A  kind  of 
box,  made  entirely  of  iron,  and  placed  ; 
upon  wheels,  is  wheeled  beneath  the  ! 
front  of  the  retorts,  and  into  it  a  portion  I 
of  ihc  fiery  contents  of  each  retort  13  ! 


drawn.  The  box  is  wheeled  away,  and 
in  a  few  minutes  volumes  of  steam  are 
ascending  profusely  from  it,  the  result 
of  a  plentiful  supply  of  water,  which  is 
thrown  on  it  for  the  sake  of  speedy  cool- 
ing. The  remainder  of  the  coke  is  then 
drawn  out  on  the  iron  floor  of  the 
building,  and,  after  being  partially  cool- 
ed by  water,  is  removed  out  into  the  open 
air. 

In  the  upper  part  of  every  retort  is  an 
opening  from  which  ascends  a  vertical 
pipe  three  or  four  inches  in  diameter. 
The  gas,  as  it  is  formed,  having  no  other 
outlet,  ascends  this  pipe,  passes  thence  to 
another  pipe  placed  horizontally,  and 
then  enters  a  descending  pipe,  which 
dips  into  a  large  main  fourteen  or  fifteen 
inches  in  diameter.  This  main  is  placed 
horizontally  along  the  whole  length  of 
the  retort-house,  and  receives  all  the  gas 
from  the  whole  range  of  retorts  on  one 
side,  there  being  two  mains  on  oppo- 
site sides  of  each  retort-house.  _  In  these 
mains  commences  that  purification  of  the 
gas  which  is  the  object  of  four  successive 
processes,  carried  on  in  four  distinct 
kinds  of  apparatus,  viz.  the  hydraulic 
mains,  the  condensers,  the  purifiers,  and 
the  saturators.  As  may  be  readily  sup- 
posed, the  transference  of  the  various 
products,  such  as  gas,  tar,  ammoniacal 
liquor,  &c,  from  vessel  to  vessel,  requires 
a  large  assemblage  of  pipes,  some  of 
which  are  carried  underground,  and 
others  within  view. 

The  retort-houses,  such  as  have  just 
been  described,  are  four  in  number ;  two 
situated  in  the  northern  quadrangle,  and 
the  other  two  being  placed  parallel  and 
contiguous  in  the  central  building  of  the 
southern  quadrangle.  To  these  a  series 
of  smaller  rooms  are  attached  to  the 
southern  end  of  the  retort-houses,  and 
within  view  from  the  entrance-gates. 
One  of  these  is  the  office  of  the  superin- 
tendent of  the  works,  and  the  other  two 
contain  very  ingenious  specimens  of  ap- 
paratus whereby  he  can  regulate  the  sup- 
ply of  gas  at  all  hours  of  the  day,  calculate 
how  much  gas  has  been  made  within  a 
certain  period,  ascertain  the  rate  at 
which  it  is  being  manufactured  at  any 
particular  time,  and  keep  a  check  over 
the  labors  of  the  men.  One  of  these 
rooms  is  called  the  'valve-room,'  and 
contains  the  apparatus  for  regulating  the 
pressure  and  supply  of  the  gas.  To  un- 
derstand the  use  ot  such  apparatus,  it  is 
necessary  to  recall  to  mind  the  striking 
change  which  occurs  throughout  a  large 
city  as  evening  is  drawing  on.  The  lamp- 


gas] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


203 


lighter  is  seen  busily  hastening  from 
lamp  to  lamp,  placing  his  slight  ladder 
against  the  street  lamp-irons,  and  kind- 
ling the  flames  which  give  to  our  streets 
no  small  share  of  their  evening  attrac- 
tions ;  the  shopkeeper  begins  to  illumi- 
nate his  wares,  with  one  blaze  if  he  be  a 
humble  dealer,  with  a  dozen  if  his  house 
b  e  a  '  gin-palace,'  with  a  score  or  two  if 
he  sells  '  unparalleled  bargains1  in  linen 
drapery;  the  theatres,  the  club-houses, 
the  evening  exhibition-rooms — all  begin 
to  display  a  blaze  of  light  near  about  one 
time.  Now  it  must  be  obvious  that  the 
sudden  demand  thus  created  is  enor- 
mous, and  it  may  be  easily  conceived 
that  great  judgment  is  required  in  ad- 
justing the  supply.  In  order  that  the 
gas  may  be  propelled  through  the  main- 
pipes  from  the  factory  to  the  remotest 
point  supplied  from  the  works,  it  is  ne- 
cessary to  give  the  gas  a  pressure  or  elas- 
tic force  greater  than  that  of  the  atmos- 
{>here.  If  this  pressure  be  too  small,  the 
ights  at  remote  places  would  burn  much 
too  faintly ;  if  tob  large,  the  flames  would 
become  so  strong  as  to  consume  an  inor- 
dinate quantity  of  gas  ;  if  the  gas  flowed 
from  the  gasometers  at  an  hour  before 
dusk  at  the  same  rate  as  at  an  hour 
after  dusk,  the  utmost  confusion  and  ir- 
regularity would  occur.  To  obviate  these 
evils  is  the  object  of  the  pressure  appara- 
tus. Around  the  valve-room  are  placed 
valves  connected  with  the  great  main. 
There  are  several  mains  branching  out 
from  the  factory  in  as  many  different  di- 
rections, for  the  supply  of  different  parts 
of  the  town;  and  as  each  main  requires  a 
supply  of  gas  proportionate  to  the  nature 
and  extent  of  the  district  through  which 
it  passes,  a  pressure-apparatus  is  attached 
to  it  distinct  from  the  others.  Directing 
attention  to  one  main  only,  it  may  be 
stated  that  after  the  gas  leaves  the  gaso- 
meters and  enters  the  main,  it  is  placed 
in  communication  with  a  small  tube  lead- 
ing to  a  '  pressure-indicator,'  by  which 
the  exact  pressure  at  any  time  of  the  day 
or  night  is  determined.  So  long  as  the 
pressure  is  such  as  is  required,  no 
changes  are  made ;  but  when  it  is 
either  too  great  or  too  small,  recourse  is 
had  to  a  valve,  whose  interior  apparatus 
is  in  connection  with  the  main.  If  the 
pressure  is  too  great,  the  valve  is  drawn 
partly  across  the  main,  by  which  the  sup- 
ply of  gas  is  slackened  :  if  too  small,  the 
valve  is  opened  more  than  before,  to  ad- 
mit a  greater  volume  of  gas.  These  ad- 
justments are,  as  was  before  observed, 


made  in  the  'valve-room,'  every  main 
!  having  its  own  'pressure-indicator1  and 
!  its  own  '  valve.' 

A  room  adjacent  to  the  one  just  men- 
I  tioned,  and  called  the  "  meter-room,1'  ex- 
hibits to  view  a  cast-iron  case,  about  ten 
I  feet  square,  and  seven  or  eight  feet  high, 
|  occupying  the  centre  of  the  room.  On 
the  front  are  six  or  eight  small  dials,  like 
clock-faces,  and  at  the  back  are  two  pipes 
ascending  through  the  floor,  and  entering 
the  case.  All  the  gas  made  at  the  works 
passes  into  this  case  or  "  meter11  by  one 
of  the  pipes  just  spoken  of,  and  leaves  it 
by  the  other.  The  meter  will  contain  a 
certain  known  quantity  of  gas  ;  and  while 
this  quantity  is  passing  through  the  ma- 
chine, an  index  hand  "is  caused,  by  me- 
chanism within  the  case,  to  revolve  once 
round  a  dial-plate.  Every  ten  revolutions 
of  this  hand  causes  another  index  to  re- 
volve once  round  another  dial-plate  ;  ten 
of  these  latter  revolutions  cause  one  revo- 
lution of  a  third  index ;  and  so  on  through 
six  successive  stages,  the  last  index  re- 
volving only  once  while  a  million  cubic 
feet  of  gas  are  passing  through  the  meter. 
The  superintendent,  by  looking  at  the  in- 
dications in  these  six  dial-faces,  is  thus 
able  to  tell,  even  to  a  single  foot,  how 
much  gas  has  passed  through  the  meter 
to  the  main  pipes.  There  are  two  other 
dials  on  the  front  of  the  meter,  one  of 
which  is  a  regular  clock,  and  the  other  an 
ingenious  arrangement  for  showing  the 
rate  at  which  the  gas  is  passing  through 
the  meter  at  any  particular  time. 

The  operations  of  a  gas  factory  are  in- 
terminable from  the  beginning  to  the  end 
of  the  year.  No  cessation,  even  for  a 
moment,  occurs  in  the  labors.  One 
party  of  men  are  engaged  at  night ;  an- 
other party  relieve  them  after  an  interval 
of  twelve  hours,  and  are  employed  by 
day ;  but  the  furnaces  are  always  heated, 
the  retorts  always  supplied  with  their 
fiercely  burning  contents,  the  gas  always 
undergoing  the  purifying  processes  pre- 
vious to  its  passage  into  "the  gasometers. 
The  number  of  retorts  worked  varies  at 
different  seasons  of  the  year,  according  to 
the  length  of  time  between  sunset  and 
sunrise;  for  the  gas-manufaeturer  is  re- 
gulated, more  perhaps  than  most  other 
manufacturers,  by  the  movements  of  the 
sun.  But  whether  the  number  actually 
worked  at  any  one  time  be  greater  or 
smaller,  the  system  pursued  is  nearly  the 
same.  At  the  works  we  have  noticed, 
the  retorts  are  so  divided  into  groups  that 
some  of  them  shall  be  ready  for  "  draw- 


204 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[gas 


ing"  every  hour.  If,  for  instance,  a 
charge  of  coals  remains  five  hours  in 
the  retort,  and  the  retorts  are  divided 
into  five  parcels  or  sets,  one  set  would  he 
filled  at  noon,  another  at  one  o'clock,  and 
the  rest  at  two,  three,  and  four  respec- 
tively. Then,  by  five  o'clock  the  first  set 
of  retorts  are  ready  to  be  drawn ;  at  six 
o'clock  the  second  set;  and  so  on  with 
the  others.  The  precise  arrangements 
need  not  be  entered  into,  hut  it  will  suf- 
fice to  say  that  exactly  as  the  clock  strikes 
each  successive  hour,  the  men  loosen  and 
remove  the  covers  of  the  retorts,  draw 
out  a  portion  of  the  coke  into  large  iron 
boxes,  draw  out  the  rest  upon  the  iron 
fioor  of  the  retort-honse,  throw  water 
on  the  coke  preparatory  to  its  removal 
from  the  retort-house,  recharge  the  re- 
torts with  fresh  coal,  replenish  the  fires 
with  a  fresh  supply  of  coke,  and  fit  the 
covers — coated  on  their  inner  surface 
with  a  thick  layer  of  lime  and  clay  cement 
— firmly  on  the  mouths  of  the  retorts.  In 
the  intervals  which  elapse  between  the 
successive  "  drawings,"  the  men  are  era- 
ployed  in  pouring  the  lime-water  into  the 
troughs  beneath  the  fireplaces,  in  placing 
new  layers  of  cement  on  the  retort-covers 
to  be  used  after  the  next  drawing,  in 
carrying  out  the  coke  into  the  open  air, 
and  afterwards  into  the  sheds  or  stores, 
in  bringing  coals  from  the  coal-stores  to 
the  retort-houses,  in  removing  the  ashes 
which  fall  into  the  lime-water  in  the  ash- 
pit, and  in  various  other  duties  sub- 
sidiary to  the  manufacture  of  gas.  The 
subsequent  preparation,  or  rather  perfect- 
ing ot  the  gas,  demands  hut  a  small 
amount  of  manual  labor;  it  is  in  fact 
performed  by  the  steam-engine,  which 
pumps  up  the  water  from  the  well,  trans- 
fers from  vessel  to  vessel  the  tar  and  the 
aramoniacal  liquor  abstracted  from  the 
gas,  and  sets  in  rotation  the  arms  or  fans 
in  the  purifying  vessels. 

There  is  perhaps  no  part  of  the  gas 
mechanism  which  requires  better  work- 
manship and  more  careful  attention  than 
the  pipes  which  convey  the  invisible 
agent  from  the  works  to  the  places  where 
it  is  consumed.  However  perfect  may 
be  the  mode  in  which  the  gas  is  manu- 
factured, however  plentiful  the  supply, 
yet  if  the  pipes  are  either  too  small  or 
too  large,  if  they  are  laid  either  too  hori- 
zontal or  too  much  inclined,  if  any  of  the 
innumerable  joints  are  imperfectly  fitted, 
the  most  serious  inconvenience  results. 
The  mains  vary  from  three  inches  to 
eighteen  inches  in  diameter,  indepen- 
dent of  the  small  lateral  pipes  which  pro- 


ceed from  the  mains  into  the  houses. 
The  largest  mains  are  placed  nearest  to 
the  gas-works ;  the  next  in  size  are  ap- 
propriated to  the  leading  streets  and 
thoroughfares  ;  while  the  smaller  are  for 
the  less  important  lanes  and  streets. 
Where  the  streets  are  wide,  and  the  num- 
ber of  lights  required  large,  it  is  usual  to 
lay  mains  on  both  sides  of  the  street ; 
and  the  diameters  of  these  mains  are 
made  to  depend  not  only  on  the  magni- 
tude and  importance  of  the  street,  but  on 
its  elevation,  its  distance  from  the  works, 
and  other  circumstances.  There  is  a  cir- 
cumstance attended  to  in  laying  down  the 
mains  which  is  perhaps  not  generally 
known.  They  are  laid  with  a  gradual  in- 
clination, amounting  perhaps  to  an  inch 
in  ten  or  twelve  yards,  instead  of  being 
horizontal ;  and  when  this  slope  has  con- 
tinued for  one  or  two  hundred  yards,  the 
mains  begin  to  ascend  in  a  similar  de- 
gree. The  line  of  mains  thus  ascends 
and  descends  alternately  throughout  its 
whole  length.  The  reason  for  this  ar- 
rangement is,  that  a  small  deposition  of 
fluid  takes  place  in  the  mains  ;  and  this 
fluid,  by  flowing  down  the  inclined  pipes, 
accumulates  at  the  lower  points,  where 
two  descending  lines  meet ;  here  a  reser- 
voir is  formed,  into  which  the  liquid 
flows,  and  by  the  occasional  use  of  a  small 
pump  from  above  the  inconvenience  is 
removed. 

When  gas  is  made  from  coal,  the  selec- 
tion of  the  coal  becomes  an  object  The 
most  bituminous  is  most  desirable,  and 
what  is  termed  Cannel  coal  is  usually 
preferred.  The  Philadelphia  Gas  Com- 
pany use  Virginia  (Richmond)  coal,  while 
the  two  New  York  companies  use  two 
parts  of  Cannel  coal  and  one  part  of  New- 
castle. The  compositions  of  these  two 
varieties  are  given,  by  Richardson — 

Newcastle.  Cannel. 

Carbon 84-846      67"597 

Hydrogen  ....  5-048      5405 

SSmi-  *»  ::::::  »*» 

When  these  coals  are  heated  to  redness 
in  closed  vessels,  the  following  process 
results  : — A  coaly  residue  (coke)  remains, 
and  certain  volatile  products  escape, 
which  partly  condense  on  cooling  into 
tar  and  an  aqueous  fluid,  while  the  rest 
is  a  mixture  of  gases,  but  contains  also  no 
inconsiderable  portion  of  the  volatile  va- 
pors of  different  compounds,  which  re- 
main dissolved  in  the  coal  gases  without 
being  condensed  into  liquids.  These  are 
oily  products,  mostly  hydro-carbons,  with 
a  large  proportion  of  carbon ;  to  these 


gas] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


205 


belong  kyanol,  leucol,  pyrole,  rosolic  and 
carbonic  acids  and  napthaline;  most  of 
these  contain  90  per  cent,  of  carbon,  nap- 
thaline as  much  as  94  per  cent.,  and  in 
burning  they  deposit  it  in  greater  quan- 
tity than  olefiant  gas.  These,  therefore, 
enhance  very  much  the  illuminating 
power  of  the  gas.  Illuminating  gas  is 
not  a  definite  compound  of  one  or  two 
gases,  as  carburetted  hydrogen  or  olefi- 
antT  gas,  but  a  mechanical  mixture  of 
very  various  bodies,  some  of  which  are 
only  slightly  luminous,  some  absolutely 
prejudicial  for  illumination,  whilst  others 
are  exceedingly  luminous,  as  olefiant 
gas  and  the  carbo-hydrogens,  possessing 
similar  properties,  and  to  which  the  mix- 
ture owes  its  illuminating  properties. 
By  distilling  coal,  we  have  left  behind 
the  solid  coke  in  the  retort,  and  then  are 
given  off,  as  volatile  matters,  a  number 
of  gases,  vapors,  and  liquids  which 
separate  in  their  passage,  and  are  received 
in  the  tar-cistern  and  condenser.  The 
liquids  consist  of,  first,  coal  tar,  which, 
on  redistilling,  yields  pitch,  coal  oil  (nap- 
tha), containing  the  hydro-carbons  noticed 
above ;  and,  second,  of  ammoniaml  li- 
quor, containing  water,  hydro-sulphate, 
carbonate,  muriate,  acetate,  hydrocyauate, 
sulphite,  and  gallate  of  ammonia. 

The  gases  and  vapors  may  be  divided 
into  three  classes.  First,  those  separated 
by  the  lime  purifier,  viz.  carbonic,  hydro- 
sulphuric,  and  hydrocyanic  acids  and  am- 
monia. Second,  those  separated  by 
water  or  in  the  alum,  or  green  vitriol  puri- 
fier, viz.  ammonia  (and  nydrocyanic  acid 
by  green  vitriol).  Third,  those  which 
pass  on  to  the  gasometer,  viz.  trace  of 
naptha  vapor,  trace  of  vapor  of  sulphuret 
carbon,  nitrogen,  hydrogen,  carbonic 
oxide,  light  carburetted  hydrogen,  and 
olefiant  gas. 

These  numerous  substances  are  not  af- 
forded in  the  same  relative  proportions, 
at  the  same  periods  of  the  distillation. 
On  the  first  application  of  the  heat  to  coal, 
steam,  along,  with  the  air  of  the  retort, 
comes  off ;  as  the  heat  approaches  red- 
ness, tar  is  disengaged,  but  only  a  small 
proportion  of  gas  below  a  red  heat ;  and 
such  gas  has  a  feeble  illuminating  power ; 
when  the  retort  is  heated  bright  red,  the 
evolution  of  gas  is  at  its  maximum,  but  tar 
is  still  produced,  though  slowly.  At  a 
white  heat,  carried  on  for  two  hours,  the 
tar  is  small  in  proportion,  that  of  the  gas 
is  still  large,  biit  decreasing.  At  length, 
the  gas  ceases  to  be  given  off.  Mr.  Peck- 
ston's  table,  showing  the  relative  amount 
of  gas  given  off  from   one  chaldron  of 


Newcastle  coal  at  different  periods  of  the 
process,  illustrates  this — 

In  1st    hour 2000  cubic  feet 

"    2d.      "     1495      " 

"    3d.      "    138T      "        " 

"    4th.     "     1279      " 

"    5th.     "     11S9      " 

"6th.     "    991      " 

"    7th.     "    884      "        " 

■    8th.     "     775      ■        " 


Total  in  8  hours 10,000  cubic  feet. 

The  composition  and  illuminating  power 
of  gas  produced  at  different  periods  of 
the  process,  vary  considerably.  The  gas 
evolved  before  the  retort  is  red  hot,  con- 
tains a  great  deal  of  carbonic  oxide,  hence 
its  feeble  illuminating  power ;  that  pro- 
duced at  a  bright  red  heat  contains  a 
larger  portion  of  olefiant  gas  and  vapors 
of  hydro-carbons,  than  what  is  formed  at 
a  higher  or  lower  temperature.  As  dis- 
tillation advances  the  temperature  in- 
creases ;  the  proportion  of  illuminating 
gas  decreases,  while  that  of  carbonic  oxide 
and  hydrogen  increases  in  proportion. 
The  density  of  the  gas  is  also  in  some  de- 
gree in  proportion  to  its  illuminating 
power,  but  decreases  as  the  heat  ad- 
vances. Dr.  Henry's  table,  here  annex- 
ed, shows  the  nature  of  the  gas  evolved 
from  Cannel  coal,  at  different  periods  of 
the  process : — 


Olefiant  gas  and 
vapors  of  hydro- 
carbons   

Light  carburetted 
hydrogen  

Carbonic  oxide.. 

Hydrogen 

Nitrogen  gas 


13 


82-5 
32 


12. 

72- 
1-9 
8-8 
5-3 


'100.0 


12.        7' 

58-  56- 

12-3  11- 

16-  21-8 

1-7  4-7 

100-0  100-0 


No.  1,  2,  and  3  were  produced  during  the 
first  hour,  4  at  the  commencement  of  the 
6th  hour,  and  No.  5  10  hours  from  be- 
ginning. 

After  those  various  liquid  and  gase- 
ous substances  are  obtained,  they  have 
to  be  separated  so  as  to  isolate  the  illu- 
minating gases  :  the  first  step  is  to  pass 
the  whole  of  the  volatile  matters  through 
the  condenser.  The  warm  gases  which 
issue  [have  a  tendency  to  condense  and 
stop  up  the  tubes]  are  conducted  to 
the  coolers  or  condensers,  which  are  of 
various  construction.  Ordinarily  it  con- 
sists of  an  iron  chest  filled  with  water, 
and  having  a  false  bottom ;  a  series  of 
tubes   connected  by  saddle  joints  are  in 


206 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[gas 


the  box.  The  lower  part  of  this  is  di- 
vided into  cells  in  which  the  fluids  col- 
lect until  they  reach  the  level  of  a  draw- 
ing-off  tube,  and  they  are  thus  separated 
— other  condensers  consist  of  a  high  per- 
pendicular tank,  with  a  system  of  zig-zag 
gas  tubes,  over  which  an  uninterrupted 
shower  of  water  rains  from  above.  On 
leaving  the  condenser  the  whole  of  the 
gases  are  still  retained ;  several  of  those 
are  useless,  as  carbonic  oxide  and  hydro- 
gen, which  burn  with  a  very  slight  evo- 
lution of  light,  and  only  tend  to  dilute 
the  gas :  others,  on  the  contrary,  are  det- 
rimental, as  ammonia,  combined  with 
carbonic,  muriatic,  and  sulphuric  and 
sulphurous  acids  and  sulphuretted  hydro- 
gen. The  purification  of  the  gas  only 
removes  the  latter  class,  not  the  former. 
The  lime  purifier  consists  of  a  cham- 
ber containing  milk  of  lime,  stirred  up 
with  water,  and  agitated  with  a  stirrer : 
the  gas  is  passed  through  it  in  a  very 
fine  stream  of  bubbles.  This  removes  the 
carbonic  acid  and  sulphuretted  hydro- 
gen, but  appears  to  diminish  the  illumi- 
nating power  of  the  gases.  To  separate 
the  ammonia  a  solution  of  alum  is  some- 
times used.  Protosulphate  of  iron  has 
been  used  for  the  same  purpose.  Dilute 
sulphuric  acid  removes  the  ammonia 
much  more  rapidly,  forming  a  sulphate 
of  ammonia,  which  is  produced  in  gas 
works  in  large  quantity,  and  is  sold  either 
to  farmers  as  manure,  or  to  manufacturers 
for  the  formation  of  other  salts  of  am- 
monia. Washing  the  gas  with  water,  will 
by  itself  separate  the  ammonia.  Mallet 
proposes  to  transmit  the  gas  through 
two  purifiers,  one  a  solution  of  green 
vitriol  or  sulphate  of  manganese,  and  the 
other  one  ot  milk  of  lime.  This  is  the 
most  profitable  and  least  laborious  plan. 
When  gas  has  been  thus  prepared  and 
purified,  it  has  a  composition  variable  as 
the  coal  used,  and  the  heat  and  time  of 
the  operation.  The  composition  marked 
No.  1  in  Henry's  table,  is  a  very  pure  gas. 
During  the  present  year,  while  public 
attention  in  New  Yorkwas  turned  toward 
the  cost  and  purity  of  gas,  the  two  gas 
companies  of  that  city  (the  Manhattan 
Co.  and  the  New  York  Co.)  jointly  re- 
quested Drs.  Torrey,  Ellet,  and  Chilton, 
to  undertake  a  thorough  investigation 
and  analysis  of  the  gases  of  both  com- 
panies, as  well  as  that  of  the  Philadel- 
phia City  Gas  Co.,  and  the  report  of 
these  chemists  appeared  on  the  22d 
May.  The  plan  of  their  investigation 
and  character  of  the  experiments  were 
those  most  likely  to  insure  accuracy  and 


involve  means  of  detection  not  previously 
used  in  Europe.  The  following  is  an  ab- 
stract from  their  report : — 

"The  following  we  believe  represents 
the  true  constitution  of  the  Philadelphia 
gas,  as  delivered  to  the  consumers  from 
April  15th  to  April  24th,  and  of  the  Man- 
hattan and  New  York  Companies'  gases 
from  April  24th  to  May  22d. 


by  Chlorine,  [  HJ^^ 

LightCarbureited  Hydrogen 

Carbonic  Oxide 

Hydrogen 

Nitrogen 


•£  —  • 

■§. 

iSjf-f 

=.J" 

3 

Sal 

£ 

zero 

2.30 

5.65 

4.20 

6.85 

37.75 

©  10 

7-50 

8.40 

45.38 

33.20 

2.87 

3.80 

100.00 

lOO.OOl 

1-^ 

m 

5.60 

6.40 

48.00 
7.50 

30-20 
2.30 

L00.00 


"All  of  the  gases  are  effectually  cleansed 
from  carbonic  acid  and  from  sulphuret- 
ted hydrogen,  not  the  slightest  traces  of 
either  of  them  being  discernible  by  the 
most  delicate  re-agents.  The  lime  puri- 
fiers seem  to  perform  their  office  tho- 
roughly, and  the  gases  have  a  less  offen- 
sive odor  than  was  formerlv  the  case. 
Ammonia  has  been  detected  in  all  of 
them,  but  the  quantity  is  very  minute, 
and  has  not  yet  been  estimated". 

"  It  will  be  seen  from  the  above  results 
that  the  New  York  gases  resemble  each 
other  very  closely,  (as  might  have  been 
anticipated,)  since  their  manufacture  is 
conducted  as  nearly  as  possible  in  the 
same  way,  and  the  materials  employed 
in  their  production  are  the  same,  viz., 
two-thirds  of  Cannel  coal,  and  one-third 
of  Newcastle  coal.  They  have  both  an 
advantage  over  the  Philadelphia  iras 
in  the  greater  relative  quantity  ot  their 
two>  most  valuable  constituents,  viz., 
olefiant  gas,  and  hydro-carbon  vapors. 

"Photometrical  processes  are  obviously 
the  most  reliable  for  determining  the 
relative  illuminating  value  of  different 

fases,  and  they  accordingly  have  not 
een  neglected  by  us.  The  comparisons 
have  been  made  by  means  of  a  standard 
candle  of  Judd's  manufacture,  which 
itself  has  been  compared  with  a  standard 
candle  used  in  the  English  gas  works, 
and  which  had  been  employed  within  a 
few  months  in  determining:  the  relative 
value  of  their  products.  We  have  thus 
been  enabled  to  compare  the  illuminating 
values  of  the  American  gases  on  which 
we  have  experimented,  not  only  with 


gel] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


207 


each  other,  but  also  with  those  of  Great 
Britain.  It  results  from  our  experiments 
that  no  appreciable  difference  in  this 
respect  exists  in  the  New  York  gases, 
the  slight  excess  of  defiant  gas  and  hy- 
dro-carbon vapors  in  the  one,  being  com- 
pensated by  the  greater  quantity  of  light 
carburetted  hydrogen  in  the  other. 

"  The  quality  of  these  gases  we  believe 
to  be  better  than  that  of  most  of  those 
manufactured  in  the  principal  cities  of 
Great  Britain,  and  if  excelled  by  any  of 
them,  it  is  only  by  those  which  are  de- 
rived from  pure  Cannel  coal. 

"  We  find  that  the  New  York  gases  are 
of  decidedly  superior  value  to  that  manu- 
factured in  Philadelphia,  and  that  to 
obtain  a  certain  definite  quantity  of  light, 
we  must  employ  them  in  quantities 
represented  by  the  following  numbers — of 

Manhattan  Gas, 100    cubic  feet, 

New  York  Company's  Gas. ...  100        "       " 
Philadelphia  Gas, 152.3     "       " 

"  Hie  values  of  these  gases  as  sources  of 
light  are  of  course  inversely  as  these  num- 
bers. 

"  We  do  not  attach  much  importance  to 
specific  gravity  as  exhibiting  the  worth 
of  an  illuminating  gas.  Carbonic  oxide, 
and  nitrogen,  (the  one  of  very  little  value, 
and  the  other  absolutely  worthless,)  are 
always  present  in  these  gases,  and  are 
both  identical  in  specific  gravity  with 
olefiant  gas,  which  is  one  of.  their  most 
valuable  constituents;  a  circumstance 
which  renders  the  test  an  unreliable  one, 
except  in  connection  with  other  charac- 
ters. We  have,  however,  made  many 
trials  on  these  gases,  and  have  found  that 
the  specific  gravity  of  the  Philadelphia 

fas  is  below  450,  while  that  of  both  the 
lanhattan  and  New  York  Companies' 
gases  is  on  the  average  550,  atmospheric 
air  being  1000. 

Good  gas  furnished  at  moderate  prices 
is  still  a  desideratum,  and  has  led  to  the  use 
of  camphene  and  water  gas  manufactured 
on  a  small  scale.  The  cost  of  coal  gas 
might  be  diminished  by  the  sale  of  the 
waste  substances  produced  as  Coke,  Sul- 
phate of  Ammonia,  Gas  Lime,  and  Tar. 
(See  Oir,  Gas,  Resin  Gas,  and  Water  Gas.) 
GAUGE-POINT,  is  a  term  used  in 
gauging  to  denote  the  diameter  of  a  cy- 
linder whose  altitude  is  one  inch,  and  its 
contents  equal  to  that  of  a  unit  of  a  given 
measure.  For  example,  the  old  wine 
gallon  contained  321  cubic  inches.  The 
diameter  of  a  cylinder  of  the  same  capa- 
city, and  whose  altitude  is  one  inch,  is 
17*15  inches ;  which,  therefore,  is  the 
gauge-point  for  this  measure. 


GAUGING,  in  mensuration,  is  the 
measuring  of  the  capacities  of  vessels, 
chiefly  casks,  barrels,  vats,  &c,  and  de- 
termining the  contents  of  the  substances 
contained  in  them.  The  principles  of 
gauging  are  those  which  geometry  fur- 
nishes for  the  measurement  of  solids  in 
general ;  but  as  the  contents  of  vessels  of 
the  kind  now  mentioned  are  so  frequent- 
ly required  to  be  known,  at  least  approxi- 
mately, for  the  purposes  of  commerce 
and  the  collection  of  the  revenue,  a  set 
of  technical  rules  and  appropriate  instru- 
ments have  been  contrived,  by  the  help 
of  which  the  art  can  be,  and  generally  is, 
practised  mechanically  by  those  who  are 
utterly  ignorant  of  the  principles  on 
which  it  depends.  The  instrument  ge- 
nerally used  for  the  purpose  is  the  gaug- 
ing-rod,  or  diagonal-rod,  by  which  the 
contents  of  a  cask  are  inferred  from  its 
diagonal  length,  measured  from  the  bung 
to  the  extremity  of  the  opposite  stave  at 
the  head.  On  one  face  of  a  square  rule, 
generally  about  four  feet  long,  is  a  scale 
of  inches  for  taking  the  measure  of  the 
diagonal ;  and  on  the  opposite  face  is  a 
scale  expressing  the  corresponding  con- 
tents of  the  cask  in  gallons.  It  is  obvi- 
ous that  this  method  of  proceeding  can 
only  give  approximate  results,  on  the 
supposition  that  all  casks  are  similar 
soiias. 

GELATINE  is  an  animal  product  which 
is  never  found  in  the  humors,  but  it  may 
be  obtained  by  boiling  with  water  the 
soft  and  solid  parts  ;  as  the  muscles,  the 
skin,  the  cartilages,  bones,  ligaments, 
tendons,  and  membranes.  Isinglass  con- 
sists almost  entirely  of  gelatine.  This 
substance  is  very  soluble  in  boiling  wa- 
ter* the  solution  forms  a  tremulous  mass 
of  icily  when  it  cools.  Cold  water  has 
little  action  upon  gelatine.  Alcohol  and 
tannin  (tannic  acid,  see  Gall-nuts)  pre- 
cipitate gelatine  from  its  solution ;  the 
former  by  abstracting  the  water,  the  lat- 
ter by  combining  with  the  substance 
itself  into  an  insoluble  compound,  of  the 
nature  of  leather.  No  othei  acid,  except 
the  tannic,  and  no  alkali  possesses  the 
property  of  precipitating  gelatine.  But 
chlorine  and  certain  salts  render  its  solu- 
tion more  or  less  turbid ;  as  the  nitrate 
and  bi-chloride  of  mercury,  the  proto- 
chloride  of  tin,  and  a  few  others.  Sul- 
phuric acid  converts  a  solution  of  gelatine 
at  a  boiling  heat  into  sugar.  (See  Ligne- 
ous Fibre.)  Gelatine  consists  of  carbon, 
47-88 ;  hydrogen,  7*91  ;  oxygen,  27*21 
(See  Glue.) 

Gelatine  brut  fin,  is  from  the  skulls, 


208 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[GEN 


blade-bones,  and  shank-bones  of  sheep, 
the  ends  cut  off,  the  bones  cut  down  the 
middle  to  remove  the  fat,  steeped  in  mu- 
riatic acid,  then  in  boiling  water  a  few 
minutes,  wiped  carefully,  dried,  shaken 
together  in  a  bag  to  remove  the  internal 
pellicle,  cut  across,  or  into  dice,  to  dis- 
guise them,  and  finally  dipped  in  a  hot 
solution  of  gelatine  to  varnish  them.  It 
is  used  to  make  soup,  keeps  better  than 
the  cakes  of  portable  soup ;  and,  less 
carefully  prepared,  makes  carpenters' 
glue  for  fine  work. 

Very  recently,  a  very  beautiful  spark- 
ling gelatine  has  been  prepared  under  a 
patent  granted  to  Messrs.  J.  &  G.  Cox, 
of  Edinburgh.  By  their  process  the  sub- 
stance is  rendered  perfectly  pure,  while 
it  possesses  a  gelatinizing  force  superior 
even  to  isinglass.  It  makes  a  splendid 
calves'  feet  jelly  and  a  milk-white  blanc- 
mange. The  patentees  also  prepare  a 
semi-solid  gelatine,  resembling  jujubes, 
which  readily  dissolves  in  warm  water, 
as  also  in  the  mouth,  and  may  be 
employed  to  make  an  extemporaneous 
jelly. 

The  gelatine  of  bones  may  be  extracted 
best  by  the  combined  action  of  steam 
and  a  current  of  water  trickling  over 
their  crushed  fragments  in  a  properly 
constructed  apparatus.  When  the  gela- 
tine is  to  be  used  as  an  alimentary  arti- 
cle, the  bones  ought  to  be  quite  fresh, 
well  preserved  in'brine,  or  to  be  dried 
strongly  by  a  stove.  Bones  are  best 
crushed  by  passing  them  between  grooved 
iron  rolls.  The  cast-iron  cylinders  in 
which  they  are  to  be  steamed,  should  be 
three  times  greater  in  length  than  in 
diameter.  To  obtain  1,000  rations  of 
gelatinous  soup  daily,  a  charge  of  four 
cylinders  is  required ;  each  being  3*  feet 
long,  by  14  inches  wide,  capable  of  hold- 
ing 70  lbs.  of  bones.  These  will  yield 
each  hour  about  20  gallons  of  a  strong 
jelly,  and  will  require  nearly  1  gallon 
of  water  in  the  form  of  steam,  and  5  gal- 
lons of  water  to  be  passed  through  them 
in  the  liquid  state.  The  5  quarts  of  jelly 
produced  hourly  by  each  cylinder,  pro- 
ceeds from  the  1  quart  of  steam-water 
and  4  quarts  of  percolating  water. 

GEMS  are  precious  stones,  which,  by 
their  color,  limpidity,  lustre,  brilliant 
polish,  purity,  and  rarity,  are  sought 
after  as  objects  of  dress  and  decoration. 
They  form  the  principal  part  of  the 
crown  jewels  of  Kings,  not  only  from 
their  beauty,  but  because  they  are  sup- 
posed to  comprise  the  greatest  value  in 
the  smallest  bulk;  for  a  diamond,  no 


larger  than  a  nut  or  an  acorn,  n  ay  be  the 
representative  sign  of  the  territorial  value 
of  a  whole  country,  the  equivalent  in 
commercial  exchange  of  a  hundred  for- 
tunes, acquired  by  severe  toils  and  pri- 
vations. 

Among  these  beautiful  minerals  man- 
kind have  agreed  in  forming  a  secret 
class,  to  which  the  title  of  gems  or  jewels 
has  been  appropriated;  while  the  term 
precious  stones  is  more  particularly  given 
to  substances  which  often  occur  under  a 
more  considerable  volume  than  fine  stones 
ever  do. 

Diamonds,  sapphires,  emeralds,  rubies, 
topazes,  hyacinths,  and  chrysoberyls,  are 
reckoned  the  most  valuable  gems. 

Crystalline  quartz,  pellucid,  opalescent, 
or  ot  various  hues,  amethyst,  lapis  lazuli, 
malachite,  jasper,  agate,  &c,  are  ranked 
in  the  much  more  numerous  and  inferior 
class  of  ornamental  stones.  These  dis- 
tinctions are  not  founded  upon  any  strict 
philosophical  principle,  but  are  regulated 
by  a  conventional  agreement,  not  very 
well  denned ;  for  it  is  impossible  to  sub- 
ject these  creatures  of  fashion  and  taste 
to  the  rigid  subdivisions  of  science.  We 
have  only  to  consider  the  value  currently 
attached  to  them,  and  take  care  not  to 
confound  two  stones  of  the  same  color, 
but  which  may  be  very  differently  prized 
by  the  virtuoso. 

Gems,  Artificial.  These  are  made  of 
a  very  fusible,  transparent,  and  dense 
glass,  or  paste,  as  it  is  called,  containing 
a  large  proportion  of  oxide  of  lead,  and 
generally  some  borax :  the  colors  are 
given  by  metallic  oxides.  Much  of  their 
perfection  depends  upon  the  skill  with 
which  the  exact  tint  of  the  real  stone  is 
imitated,  and  upon  the  care  with  which 
they  are  cut  and  polished. 

Mr.  Ebelman,  Director  of  the  National 
Porcelain  Manufactory  of  Sevres,  has  dis- 
solved in  boric  acid,  alum,  zinc,  magne- 
sia, oxides  of  iron  and  chrome,  and  then 
subjecting  the  solution  to  evaporation 
during  three  days,  he  has  obtained  crys- 
tals equalling  in  hardness,  clearness,  and 
beauty  the  natural  stones.  With  chrome 
he  has  made  most  brilliant  rubies,  from 
two  to  three  millimetres  in  length,  and 
as  thick  as  a  grain  of  corn.  He  has  also 
made  artificially,  diaphonous  quartz,  hy- 
drophane,  and  chalcedony. 

GENEVA,  or  Hollands  gin,  is  made  by 
mashing  120  lbs.  of  malt  with  240  lbs.  of 
rye  flour,  in  480  gallons  of  water  at  162°. 
Yeast  is  added  at  80° :  and  in  two  days 
the  fermentation  raises  it  to  90°.  The 
whole,  grains  and  all,  is  then  subjected 


ger] 


CYCLOPEDIA    OP   THE   USEFUL   ARTS. 


209 


to  three  distillations,  and  before  the  last, 
juniper  berries  and  hops  are  infused. 

GEODES.  Kound  masses  or  no- 
dules of  iron-stone,  hollowed  in  the  cen- 
tre. Eounded  pebbles  having  an  internal 
cavity,  lined  with  crystals,  are  also  so 
called. 

GEODESY.  A  word  occasionally  used, 
which  literally  signifies  the  division  of  the 
earth,  in  which  sense  it  is  synonvmous 
with  land  surveying ;  but  it  is  usually  em- 
ployed in  a  more  general  sense  to  denote 
that  part  of  practical  geometry  which  has 
for  its  object  the  determination  of  the 
magnitude  and  figure  either  of  the  whole 
earth,  or  of  any  given  portion  of  its  sur- 
face. In  this  sense  it  comprehends  all 
the  geometrical  or  trigonometrical  opera- 
tions that  are  necessary  for  constructing 
a  map  of  a  country,  measuring  the 
lengths  of  degrees,  &c.  In  order  to  con- 
struct an  accurate  map,  or  determine  the 
form  and  dimensions  of  a  country,  it  is 
necessary,  in  the  first  place,  to  determine 
the  absolute  distances  oetween  the  seve- 
ral stations  or  points;  secondly,  to  de- 
termine the  azimuths  of  the  lines  thus 
measured,  that  is,  their  situation  with 
respect  to  the  meridian  ;  and  thirdly,  the 
differences  of  latitude  and  longitude  of 
the  stations.  The  operations  necessary 
for  determining  the  absolute  distances, 
comprehending  the  measurement  of  a 
base,  the  observation  of  angles,  the  com- 
putation of  the  sides  of  the  triangles,  and 
their  reduction  to  the  same  level,  are 
called  the  geodesical  or  geodetical  opera- 
tions ;  while  those  which  are  required 
for  determining  the  azimuths  and  lati- 
tudes are  called  the  astronomical  opera- 
tions. The  determination  of  the  figure 
and  dimensions  of  the  earth  is  a  problem 
of  very  great  importance  to  astronomy 
and  geography,  and  has  accordingly  at 
all  times  been  a  subject  of  much  interest 
to  mathematicians  ;  but  it  is  only  since 
towards  the  middle  of  the  last  century 
that  operations  on  an  adequate  scale  for 
its  solution  have  been  undertaken  in  dif- 
ferent parts  of  the  world.  Further  de- 
tails do  not  come  within  the  scope  of 
this  volume.     See  Theodolite. 

GERMAN  SILVER.  See  close  of  the 
article  Copper. 

GERMINATION,  or  Budding.  The 
process  by  which  a  plant  is  produced 
from  a  seed.  The  phenomena  of  germi- 
nation are  best  observed  in  dicotyledo- 
nous seeds ;  such,  for  instance,  as  the 
bean,  pea,  lupin,  &c.  These  seeds  con- 
sist of  two  lobes  or  cotyledons,  enveloped 
in  a  common  membrane;  when  this  is 


removed  a  small  projecting  body  is  seen, 
which  is  that  part  ot  the  germ  which  af- 
terwards becomes  the  root,  and  is  termed 
the  radicle  :  the  other  portion  of  the 
germ  is  seen  on  carefully  separating  the 
cotyledons,  and  is  termed  the  plumula ; 
it  afterwards  forms  the  stem  and  leaves. 
When  the  ripe  seed  is  removed  from  the 
parent  plant  it  gradually  dries,  and  may 
be  kept  often  for  an  indefinite  period 
without  undergoing  any  change ;  out  if 
placed  under  circumstances  favorable  to 
its  germination,  it  soon  begins  to  grow  : 
these  requisite  circumstances  are  a  duo 
temperature,  moisture,  and  the  presence 
of  air.  The  most  favorable  temperature 
is  between  60°  and  80°  ;  at  the  freezing 
point  none  of  the  more  perfect  seeds 
vegetate ;  and  at  temperatures  above 
100°,  the  young  germ  is  usually  injured. 
No  seed  will  grow  without  moisture  : 
water  is  at  first  absorbed  by  the  pores  of 
the  external  covering,  and  decomposed ; 
the  seed  gradually  swells,  its  memnranes 
burst,  and  the  germ  expands.  The  root 
is  at  first  most  rapidly  doveloped,  the 
materials  for  its  growth  being  derived 
from  the  cotyledons ;  and  when  it  shoots 
out  its  fibres  or  rootlets,  these  absorb 
nourishment  from  the  soil,  and  the  plu- 
mula  is  developed,  rising  upwards  m  a 
contrary  direction  to  the  root,  and  ex- 
panding into  stem  and  leaves.  For  this 
growth  the  presence  of  air  is  requisite ; 
if  it  be  carefully  excluded,  though  there 
be  heat  and  moisture,  yet  the  seed  will 
not  vegetate.  Hence  it  is  that  seeds 
buried  very  deep  in  the  earth,  or  in  a 
stiff  clay,  remain  inert ;  but,  on  admis- 
sion of  air  by  turning  up  the  soil,  begin 
to  shoot  forth.  From  experiments  which 
have  been  made  upon  the  germination  of 
seeds  in  confined  atmospheres,  it  ap- 
pears that  the  oxygen  set  free  by  the  de- 
composition of  water  combines  with  a 
portion  of  the  carbon  of  the  seed,  and 
carries  it  off  in  the  form  of  carbonic  acid, 
and  that  the  consequence  of  this  is  the 
conversion  of  part  of  the  albumen  and 
starch  of  the  cotyledons  into  gum  and 
sugar ;  so  that  most  seeds,  as  we  see  in 
the  conversion  of  barley  into  malt,  be- 
come sweet  during  germination.  Light 
is  injurious  to  the  growth  of  a  seed.  It 
is,  therefore,  obvious  that  the  different 
requisites  for  germination  are  attained 
by  placing  a  seed  under  the  surface  of 
the  soil  warmed  by  the  sun's  rays,  when 
it  is  moistened  by  its  humidity  and  by 
occasional  showers :  excluded  from  light, 
but  within  reach  of  the  access  of  air. 
When  the  young  plant  is  perfected, 


210 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[< 


the  cotyledons,  if  not  coverted  into 
leaves,  rot  away,  and  the  process  of  nu- 
trition is  carried  on  by  the  root  and 
leaves  :  the  principal  nourishment  is 
taken  up  from-  the  soil  by  the  root,  and 
chiefly  by  its  small  and  extreme  fibres ; 
so  that  when  these  are  injured  or  torn, 
as  by  careless  transplantation,  the  plant 
or  tree  generally  dies.  The  matters  ab- 
sorbed, consisting  of  water  holding  small 
portions  of  saline  substances,  and  of  or- 
ganic matter  in  solution,  become  the  sap 
of  the  plant ;  and  this  is  propelled  up- 
wards in  the  vessels  of  the  stem,  or  of 
the  outer  layer  of  wood,  into  the  leaves  ; 
here  it  is  exposed  to  the  agency  of  air,  or 
of  light :  it  transpires  moisture,  and  oc- 
casionally carbonic  acid.  But  the  leaves 
also  at  times  absorb  moisture,  and  ding- 
ing the  influence  of  light  they  decom- 
pose the  carbonic  acid,  and,  retaining 
the  carbon,  evolve  oxygen ;  the  sap  thus 
becomes  modified  in  its  composition,  and 
the  characteristic  proximate  principles  of 
the  vegetable  are  formed.  These  return 
in  appropriate  vessels  from  the  leaves, 
chiefly  to  the  inner  bark,  where  we  ac- 
cordingly find  the  accumulation  of  the 
peculiar  products  of  the  plant :  they  also 
enable  it  annually  to  form  a  new  layer  of 
wood.  Hence  it  is  that  the  transverse 
section  of  the  wood  exhibits  as  many  dis- 
tinct zones  as  the  tree  is  years  old.  We 
are  ignorant  of  the  causes  of  this  circula- 
tion of  the  sap ;  but  that  it  does  follow 
the  cause  which  has  been  stated  is  proved 
by  the  operation  which  gardeners  call 
ringing,  and  which  they  sometimes  re- 
sort to,  to  make  a  barren  branch  bear 
flowers  and  fruit :  it  consists  in  cutting 
out  and  removing  a  circular  ring  of  bark, 
so  as  to  prevent  the  return  of  the  sap  by 
the  descending  vessels,  which  at  first 
ooze  copiously,  but  afterwards  the  wound 
heals,  and  the  juices  are  accumulated  in 
all  parts  above  the  extirpated  riner,  pro- 
ducing tumefaction  in  the  limb,  and  often 
inducing  a  crop  of  flowers  and  fruit,  or 
causing  those  to  appear  earlier  than  on 
the  uncut  branches.  If  a  tree  be  wound- 
ed so  as  to  cut  into  the  central  portions 
of  the  wood,  or  the  outer  layer  of  new 
wood,  the  flow  of  ascending  sap  is  then 
seen  to  take  place  upon  the  lower  sec- 
tion, where  the  vessels  are  that  carry  it 
up  to  the  leaves ;  and  the  flow  of  de- 
scending sap  is  principally  confined  to  the 
upper  section  of  the  inner  bark,  from 
which,  after  a  time,  new  bark  is  pro- 
duced, and  the  parts  again  united. 

GIG.     A   well-known   kind  of  light 
carriage  drawn  by  one  horse.     Gigs,  or 


gig  machines,  are  rotatory  cylinders  co- 
vered with  wire-teeth,  for  teazling  wool- 
len cloth. 

GILDING.  The  application  of  a  su- 
perficial coat  of  gold  on  wood,  metal,  and 
other  materials.  The  beauty  and  dura- 
bility of  gold  render  it  the  most  valuable 
of  all  ornamental  substances ;  but,  on  ac- 
count of  its  weight  and  high  price,  its 
use  in  these  respects  would  be  exceed- 
ingly limited,  were  it  not  the  most  ex- 
tensible and  divisible  form  of  matter,  so 
that  it  may  be  made  to  cover  a  larger 
surface  than  an  equal  quantity  of  any 
other  body.  Metals  are  usually  covered 
with  gold  by  the  process  of  water  gilding. 
It  consists  in  perfectly  cleaning  their 
surface,  and  then,  in  the  case  of  silver, 
for  instance,  rubbing  it  over  with  a  solu- 
tion of  gold  in  mercury,  called  amalgam 
of  gold :  the  vessel  is  then  heated  over  a 
clear  charcoal  fire,  by  which  the  mercury 
is  driven  off,  and  the  gold  left  adhering 
to  the  silver  surface,  upon  which  it  is 
afterwards  burnished.  The  surface  of 
copper  or  brass  is  usually  prepared  by 
cleaning  and  rubbing  it  over  with  a  so- 
lution of  nitrate  of  mercury,  which  amal- 
gamates the  surface,  and  enables  the 
gold  amalgam,  when  subsequently  ap- 
plied, to  adhere ;  heating  and  burnish- 
ing are  then  resorted  to  as  before.  Brass 
and  copper  buttons  are  gilt  in  this  way ; 
and  the  requisite  quantity  of  gold  is  so 
small  that  twelve  dozen  buttons  of  one 
inch  diameter  may  be  completely  gilt 
upon  both  surfaces  by  five  grains  of 
gold.  Other  kinds  of  gilding  are  per- 
formed by  gold  leaf,  which,  if  intended 
for  out-door  work,  is  laid  on  by  the  help 
of  gold  size,  which  is  drying  oil  mixed 
with  calcined  red  ochre ;  or,  if  for  pic- 
ture and  looking-glass  frames,  they  are 
prepared  by  a  size  made  by  boiling  parch- 
ment clippings  to  a  stiff  jelly,  and  mixed 
with  fine  Paris-plaster  or  yellow  ochre. 
The  leaves  of  books  are  gilt  upon  the 
edges  by  brushing  them  over,  while  in 
the  binder's  press,  with  a  composition  of 
four  parts  of  Arminian  bole  and  one  of 
powdered  sugar  candy  mixed  up  with 
white  of  egg ;  this  coating,  when  nearly 
dry,  is  smoothed  by  the  burnisher,  then 
slightly  moistened,  and  the  gold-leaf  ap- 
plied and  burnished.  To  impress  gilt 
figures  on  book  covers,  the  leather  is 
dusted  over  with  finely-powdered  mastic: 
the  iron  tool  by  which  the  figure  is  made 
is  then  moderately  heated  and  pressed 
upon  a  piece  of  leaf-gold,  which  slightly 
adheres  to  it. 

In  gilding  wood,  the  operator  should 


gil] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


211 


be  provided  with  a  cushion,  made  of  a 
board  about  10  inches  square,  covered 
with  leather,  and  lightly  stuffed  with 
cotton,  and  a  thumb-piece  at  the  back : 
also,  with  a  tip-brush,  a  pallet-knife,  and 
a  dabber,  or  silk  bag  filled  with  cotton. 
The  pattern  to  be  gilt  is  then  exactly 
washed  with  jappanner's  gold  size,  (lin- 
seed-oil and  gum  animi,  thinned  with 
oil  of  turpentine,)  and  the  gold  leaves 
being  cut  on  the  cushion  with  the  pallet- 
knife,  are  transferred  by  the  tip-brush 
to  the  sized  surface  and  tapped  with  the 
silk  bag,  and  left  to  dry. 

In  covering  surfaces  with  gold,  the 
size  is  made  of  3  boiled  oil,  1  japanner's 
gold  size,  with  yellow  ochre  ground  in 
boiled  oil.  Two  separate  washes  of  this 
must  be  applied  to  the  pattern,  and  be- 
fore quite  hard,  the  gold-leaf  laid  "on. 
Other  size  is  made  by  grinding  red  lead 
with  thick  drying-oil,  and  diluting  with 
turpentine  ;  and,  in  other  cases,  with 
mere  glue. 

Iron  and  steel  are  gilt  by  simply  dip- 

Eing.  The  solution  in  aqua-regia  is  to 
e  evaporated  till  it  crystallizes,  and  then, 
if  dissolved  in  water  and  alcohol,  the  iron 
may  be  dipped.  But,  if  sulphuric  ether 
be  added,  polished  steel  will  be  gilt  by 
simple  immersion. 

Silver  is  gilt  by  a  solution  of  the  gold 
in  a  menstruum  of  nitric  acid,  sal  ammo- 
niac, and  corrosive  sublimate.  It  black- 
ens the  silver,  but  a  red  heat  restores 
the  gold  color. 

The  mercurial  amalgam  can  be  applied 
to  copper,  or  brass,  or  silver,  by  wasliing 
the  surface  with  a  solution  of  dilute  sui- 
phuric  acid  and  mercury.  The  amalgam 
is  then  evenly  applied  with  a  wet  brush 
of  brass  wire.  The  heat  of  a  furnace 
evaporates  the  mercury,  and  leaves  the 
gold.  Rub  with  gilders'  wax,  and  bur- 
nish with  sted. 

Iron  is  gilt  by  heating  it  blue,  and 
laying  on  the  gold-leaf,  burnishing,  and 
heating.    Repeat  till  perfect. 

Copper  buttons  are  gilt  by  putting 
them  in  nitric  acid,  and  then  burnishing 
on  hard  stone.  Then  stir  them  in  nitric 
solution  of  mercury  till  white.  The 
amalgam  of  gold  is  then  mixed  with 
nitric  acid,  and  the  buttons  being  well 
stirred  the  gold  attaches.  By  heating, 
the  mercury  is  made  to  run,  when,  after 
trituration  in  a  hairy  bag,  farther  heat 
evaporates  it,  and  the  buttons  are  bur- 
nished. 

Gilding  in  cornices,  &c,  is  effected  by 
priming  with  boiled  linseed-oil,  and  car- 
bonate of  lead.    The  surface  is  then  co- 


vered with  gold  size,  on  which  slips  of 
gold-leaf  are  pressed  with  cotton.  The 
edges  are  then  brushed  off.  Burnished 
gilding  requires  priming  with  gum2  and 
bole  must  be  mixed  with  the  gold  size. 

Gilding  in  oil. — 1.  The  first  operation 
is  to  give  a  priming  coat  of  color,  formed 
by  grinding  white  lead  in  oil,  rendered 
drying  by  boiling  with  litharge,  and  tem- 
pered afterwards  with  linseed-oil,  adding 
a  little  fat  oil,  and  a  very  small  portion 
of  spirits  of  turpentine.  2.  Grind  cal- 
cined white  lead  very  fine  in  fat  oil ;  this 
must  immediately  be  tempered  with  oil 
of  turpentine,  as  it  is  subject  to  become 
thick  very  quickly.  Three  or  four  thin 
coats  of  this  are  to  be  given  very  evenly 
in  the  ornaments,  and  in  nil  parts  in- 
tended to  be  gilt.  Care  must  be  taken 
in  applying  the  color  to  the  deeper  parts 
of  the  work,  that  it  may  be  even  and 
perfect. — This  is  the  teinte  dure,  or  hard 
ground.  3.  The  gold  color  or  size,  pre- 
viously strained  through  fine  linen,  is 
then  to  be  laid  on,  very  thin  and  even, 
with  a  soft  brush  which  has  been  used 
for  oil  colors.  A  smaller  brush  must  be 
used  for  the  deeper  parts  of  the  sculp- 
tured or  other  ornaments,  carefully  od- 
serving  to  remove  any  hairs  which  may 
be  detached  from  the  brush.  4.  Where 
the  size  is  so  far  dried  as  to  become 
tacky,  the  gold  leaf  is  to  be  spread  upon 
the  cushion,  and  divided  with  the  knife  ; 
the  gold  is  placed  on  with  a  small  block 
of  wood,  faced  with  cloth,  called  a  pa- 
lette, and  lightly  pressed  with  cotton, 
repairing  where  necessary  with  pieces  of 

f;old  cut  small,  applied  by  a  badger's 
mir-pencil.  5.  If  the  articles  gilt  are  to 
be  exposed  to  the  weather,  as  balconies, 
gratings,  statues,  &c,  they  ought  not  to 
be  varnished,  as  gilding  in  oil  is  more 
durable  without  than  with  varnish.  The 
heat  of  the  sun  will,  after  a  heavy  rain, 
cause  gilding  covered  with  varnish  to 
craze  or  crack  over  its  whole  surface. 
Gilding  in  the  interior  of  a  building,  as 
on  the  rails  of  staircases,  &c,  should  have 
a  coat  of  spirit  of  wine  varnish,  drying  it 
by  means  of  a  chafing-dish,  and  then  ap- 
plying a  coat  of  oil  varnish.  The  beauty 
of  oil-gilding  depends  greatly  upon  the 
manner  of  varnishing  it. 

For  gilding  metal  buttons. — To  4  oz.  of 
yellow  melted  bees'-wax  add,  in  fine 
powder,  H  oz.  of  red  ochre,  li  oz.  of 
verdigris,  calcined  till  it  yields  no  fumes, 
and  i  oz.  of  calcined  borax,  and  mix  them 
well.  It  is  necessary  to  calcine  the  ver- 
digris. 

To  exalt  the  color  of  green  gold. — Take 


212 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[oil 


saltpetre  1  oz.  10  dwts.,  sal-ammoniac  1 
oz.  4  dwts.,  and  verdigris  18  dwts.,  and 
dissolve  a  portion  of  the  mixture  in 
water,  as  occasion  requires. 

To  exalt  the  color  of  yellow  gold. — Take 
saltpetre  6  oz.,  green  copperas'2  oz.,  white 
vitriol  and  alum,  of  each  1  oz.  If  the 
color  be  wanted  redder,  a  small  portion 
of  blue  vitriol  must  be  added.  To  be 
dissolved  in  water,  as  wanted. 

These  two  last  compositions  must  be 
applied  to  the  surfaces  of  the  gilt  works, 
either  with  a  pencil,  or  by  dipping  them  ; 
a  proper  degree  of  heat  must  then  be 
used  to  cause  them  to  assume  a  black 
color,  when  they  must  be  quenched,  or 
ccoled,  either  in  vinegar  or  water. 

Gilding  japan- work  is  performed  with 
japanner's  gold  size  J  and  for  dead  gold 
it  should  be  used  with  turpentine  only, 
but  for  lustre  with  fat  oil  only. 

Gilding  earthenware  and  porcelain. — 
Take  2  drs.  or  5  dwts.  of  pure  gold  and 
triturate  in  a  porcelain  mortar  carefully, 
until  very  fine  ;  add,  at  distinct  times,  1, 
2,  and  3  dwts.  of  pure  mercury,  and  mix 
well  together ;  then  add  10  grs.  of  white 
oxide  of  lead.  Or,  exclude  the  lead,  and 
1  dwt.  of  the  mercury,  when  a  strong 
body  of  gold  is  required. 

On  a  glass  plate,  long,  and  very  care- 
fully grind  for  use. 

When  the  gold  (as  on  some  occasions) 
contains  an  alloy  of  silver,  less  mercury 
must  be  taken,  and  lead  wholly  ex- 
cluded. 

In  executing  the  superior  specimens  of 
this  art,  men  are  employed  ;  and  in  many 
of  the  porcelain  manufactories  may  be 
seen  specimens  of  the  high  excellence 
of  which  it  is  susceptible,  in  flowers, 
landscapes,  and  portraits.  Other  less 
delicate  patterns  are  the  work  of  young 
women ;  of  whom,  great  numbers  pro- 
vide for  their  comforts  by  these  employ- 
ments. 

When  the  gilded  ware  has  been  through 
the  muffle,  and  is  cool,  the  gold  is  bur- 
nished with  agate  or  bloodstone ;  the  ware 
is  then  wrapped  in  tissue  paper,  and 
carefully  packed  for  home,  or  foreign 
markets. 

On  some  of  the  least  valuable  porce- 
lain, leaf-gold  is  fixed  by  being  placed  on 
a  warm  size,  formed  of  these  compo- 
nents. Boil  together  half  a  pint  of  pure 
linseed-oil,  i  oz.  of  gum  arable,  gum  ben- 
zoin, and  acetate  of  lead  severally  ;  and 
after  being  well  boiled,  cool ;  lay  evenly 
on  the  ware,  heat  the  whole  a  little,  add 
the  strips  of  leaf-gold,  and  carefully  place 
for  sale. 


To  gild  with  burnished  gold. — Give  five 
or  six  coats  of  size  and  whiting.  First 
with  varnish  of  Armenian  bole,  wax  and 
size.  Wet  with  water,  and  lay  on  the 
gold,  and  in  a  few  hours  burnish  with 
agate. 

To  gild  the  edges  of  boohs.  —  Wash 
them,  in  the  press,  with  Armenian  bole, 
sugar  candy,  and  white  of  eggs.  Wet 
with  water  and  lay  on  the  gold  leaf,  and 
burnish  with  a  dog's  tooth,  or  steel  tooth. 

Golden  articles  of  jewelry. — The  two 
best  mixtures  for  the  purpose  of  giving 
a  good  gold  color  to  articles  of  jewelry, 
are  as  follows  : — 

PARTS. 

Muriatic  acid  at  22° 10 

Oil  of  vitriol 4 

Crystall  ized  boracic  acid 2 

Water 150 

Or, 

Acid  muriate  of  alumine  (liquid) 13 

Crystallized  sulphate  of  soda 4 

Crystallized  boracic  acid 3 

Water 150 

Either  of  these  mixtures,  with  20  grs. 
of  neutral  muriate  of  gold,  constitutes 
the  bath,  which  is  to  be  used  in  the  fol- 
lowing manner : — A  large  glass  mattrass, 
carefully  luted  at  the  bottom,  is  placed 
over  a  circular  furnace,  so  as  to  have  heat 
readily  applied  to  it ;  the  solution  is  to 
be  be  put  into  it,  and  when  at  the  boiling 
point,  the  pieces  of  jewelry,  previously 
cleaned  and  picked,  are  to  be  introducecf, 
suspended  upon  golden  wires.  After  a 
few  minutes,  a  copper  wire  is  to  be  im- 
mersed, and  left  until  the  gold  has  ac- 
quired a  deep  color;  it  is  then  to  be 
withdrawn,  but  the  articles  still  left  in 
until  they  have  acquired  the  color  neces- 
sary. They  are  then  to  be  put  into  warm 
water,  acidulated  by  sulphuric  or  acetic 
acid,  to  remove  particles  of  oxide  of  cop- 

§er,  washed  in  clean  warm  water,  and 
ried  near  a  fire.  Generally,  a  single 
operation  is  not  enough ;  for,  as  a  long 
immersion  produces  harm  from  the  oxide 
of  copper,  it  is  better  to  shorten  it,  and 
repeat  the  operation. 

Gold  size. — Mix  16  oz.  of  linseed-oil,  8 
oz.  of  turpentine,  2oz.  of  asphaltum,  and 
1  oz.  each  of  brown  umber  and  of  red 
lead.  6>r,  melt  together  1  oz.  each  gum 
asphaltum  and  anime  ;  i  oz.  each  of  li- 
tharge, red  lead,  and  brown  umber ;  4 
oz.  of  linseed-oil  and  8  oz.  of  drying  oil ; 
strain. 

Gilders'1  wax  is  4  lbs.  of  bees'-wax,  a 
}  of  verdigris,  and  also  of  sulphate  of 
copper,  kept  in  a  red  heat  until  the  wax 
has  evaporated. 


gla] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


218 


Shdl  gold  may  be  obtained  by  amalga- 
mating the  metal  with  8  parts  of  mercury 
in  a  crucible,  and  then  evaporating  the 
mercury.  Or,  gold  leaf  may  be  tritu- 
rated with  gum- water,  and  the  gum  dis- 
solved and  poured  off. 

GIMBALS,  or  GIMBOLS.  A  piece  of 
mechanism  consisting  of  two  brass  hoops 
or  rings,  which  move  within  one  another, 
each  perpendicularly  to  its  plane,  about 
two  axes  placed  at  right  angles  to  each 
other. 

GLANCE  COAL.  Anthracite  :  it  is 
subdived  into  two  classes — 1st,  the  slaty ; 
and  2d,  the  conchoidal. 

GLASS  is  a  transparent  solid  formed 
by  the  fusion  of  siheious  and  alkaline 
matter.  It  was  known  to  the  Phcnicians, 
and  constituted  for  a  long  time  an  exclu- 
sive manufacture  of  that  people,  in  con- 
sequence of  its  ingredients,  natron,  sand, 
ana  fuel,  abounding  upon  their  coasts. 
It  is  probable  that  the  more  ancient 
Egyptians  were  unacquainted  with  glass, 
for  we  find  no  mention  of  it  in  the  writ- 
ings of  Moses.  But  according  to  Pliny 
and  Strabo,  the  glass  works  of  Sidon 
and  Alexandria  were  famous  in  their 
times,  and  produced  beautiful  articles ; 
which  were  cut,  engraved,  gilt,  and 
stained  of  the  most  brilliant  colors,  in 
imitation  of  precious  stones.  The  Ko- 
mans  employed  glass  for  various  pur- 
poses ;  and  have  left  specimens  in  Her- 
culaneum  of  window-glass,  which  must 
have  been  blown  by  methods  analogous 
to  the  modern.  The  Phenician  processes 
seem  to  have  been  learned  by  the  Cru- 
saders, and  transferred  to  Venice  in  the 
13th  century,  where  they  were  long  held 
secret,  and  formed  a  lucrative  commer- 
cial monopoly.  Soon  after  the  middle  of 
the  17th  century,  Colbert  enriched  France 
with  the  blown  mirror  glass  manufac- 
ture. 

Chance  undoubtedly  had  a  principal 
share  in  the  invention  of  this  curious 
fabrication,  but  there  were  circumstances 
in  the  most  ancient  arts  likely  to  lead  to 
it ;    such  as  the  fusing  and  vitrifying 
heats  required  for  the  formation  of  pot- 
tery, and   for  the   extraction  of  metals 
from    their    ores.      Pliny    ascribes    the 
origin  of  glass  to  the  following  accident. 
A  merchant-ship  laden  with  natron  being 
driven  upon  the  coast  at  the  mouth  of  ! 
the  river  Belus,  in  tempestuous  weather, 
the  crew  were  compelled  to  cook  their  i 
victuals  ashore  ;  and  having  placed  lumps  ! 
of  the  natron  upon  the  sand,  as  supports 
to  the  kettles,  found  to  their  surprise  ! 
masses  of  transparent  stone  among  the  ! 


cinders.  The  sand  of  this  small  stream 
of  Galilee,  which  runs  from  the  foot  of 
Mount  Carmel,  was  in  consequence  sup- 
posed to  possess  a  peculiar  virtue  for 
making  glass,  and  continued  for  ages  to 
be  sought  after  and  exported  to  distant 
countries  for  this  purpose. 

The  researches  of  Berzelius  having  re- 
moved all  doubts  concerning  the  acid 
character  of  silica,  the  general  composi- 
tion of  glass  presents  now  no  difficulty 
of  conception.  This  substance  consists 
of  one  or  more  salts,  which  are  silicates 
with  bases  of  potash,  soda,  lime,  oxide 
of  iron,  alumina,  or  oxide  of  lead  ;  in 
any  of  which  compounds  we  can  substi- 
tute one  of  these  bases  for  another,  pro- 
vided that  one  alkaline  base  be  left. 
Silica  in  its  turn  may  be  replaced  by  the 
boracic  acid,  without  causing  the  glass  to 
lose  its  principal  characters. 

Under  the  title  glass  are  therefore  com- 
prehended various  substances  fusible  at 
a  high  temperature,  solid  at  ordinary 
temperatures,  brilliant,  generally  more 
or  less  transparent,  and  always  brittle. 
The  following  chemical  distribution  of 
glasses  has  been  proposed. 

1.  Soluble  glass ;  a  simple  silicate  of 

{>otash  or  soda ;  or  of  both  these  alka- 
ies. 

2.  Bohemian  or  crown  glass ;  silicate 
of  potash  and  lime. 

3.  Common  window  and  mirror  glass  ; 
silicate  of  soda  and  lime  ;  sometimes  also 
of  potash. 

4.  Bottle  glass ;  silicate  of  soda,  lime, 
alumina,  and  iron. 

5.  Ordinary  crystal  glass  ;  silicate  of 
potash  and  lead. 

6.  Flint  glass ;  silicate  of  potash  and 
lead ;  richer  in  lead  than  the  preceding. 

7.  Strass  ;  silicate  of  potash  and  lead ; 
still  richer  in  lead. 

8.  Enamel ;  silicate  and  stannate  or 
antimoniate  of  potash  or  soda  and  lead. 

The  glasses  wnich  contain  several  bases 
are  liable  to  suffer  different  changes 
when  they  are  melted  or  cooled  slowly. 
The  silica  is  divided  among  these  bases, 
forming  new  compounds  in  definite  pro- 
portions, which  by  crystallizing,  separate 
from  each  other,  so  that  the  general  mix- 
ture of  the  ingredients  which  constituted 
glass  is  destroyed.  It  becomes  then  very 
ard,  fibrous,  opaque,  much  less  fusible, 
a  better  conductor  of  electricity  and  of 
heat ;  forming  what  Keaumur  styled  de- 
nitrified glass,  and  what  is  called  after 
him,  Reaumur's  porcelain. 

GLASS-MAKING,  General  Princi- 
ples of.    Glass  may  be  defined  in  tech- 


214 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gla 


nical  phraseology,  to  be  a  transparent 
homogeneous  compound  formed  by  the 
fusion  of  silica  with  oxides  of  the  alka- 
line, earthy,  or  common  metals.  It  is 
usually  colorless,  and  then  resembles 
rock  crystal,  but  is  occasionally  stained 
by  accident  or  design  with  colored  me- 
tallic oxides.  At  common  temperatures 
it  is  hard  and  brittle,  in  thick  pieces  ;  in 
thin  plates  or  threads,  flexible  and  elas- 
tic ;  sonorous  when  struck  •  fracture 
conchoidal,  and  of  that  peculiar  lustre 
called  vitreous  ;  at  a  red  heat,  becoming 
soft,  ductile,  and  plastic.    Besides  glass 

Eroperly  so  called,  other  bodies  are  capa- 
le  of  entering  into  vitreous  fusion,  as 
phosphoric  acid,  boracic  acid,  arsenic 
acid;  as  also  certain  metallic  oxides,  as 
of  lead  and  antimony,  and  several  chlo- 
rides, some  of  which  are  denominated 
glasses.  Impure  and  opaque  vitriform 
masses  are  called  slags ;  such  are  the 
productions  of  blast  iron  furnaces  and 
manv  metallurgic  operations. 

Silica,  formerly  styled  the  earth  of 
flints,  which  constitutes  the  basis  of  all 
commercial  glass,  is  infusible  by  itself  in 
the  strongest  fire  of  our  furnaces ;  but 
its  vitreous  fusion  is  easily  effected  by  a 
competent  addition  of  potash  or  soda, 
either  alone  or  mixed  with  lime  or  li- 
tharge. The  silica,  which  may  be  re- 
garded as  belonging  to  the  class  of  acids, 
combines  at  the  heat  of  fusion  with  these 
bases  into  saline  compounds ;  and  hence 
glass  may  be  viewed  as  a  silicate  of  cer- 
tain oxides,  in  which  the  acid  and  the 
bases  exist  in  equivalent  proportions. 
Were  these  proportions,  or  the  quantities 
of  the  bases  which  silica  requires  for  its 
saturation  at  the  melting  point,  exactly 
ascertained,  we  might  readily  determine 
beforehand  the  best  proportions  of  ma- 
terials for  the  glass  manufacture. 

Glass-houses  are  commonly  large  coni- 
cal buildings,  from  60  to  100  feet  high, 
and  from  50  to  80  feet  in  diameter. 

The  furnace  is  in  the  middle,  over  a 
large  vault,  which  is  connected  with  it 
by  means  of  an  opening.  This  opening 
is"  covered  with  an  iron  grate,  upon  which 
the  fire  is  made,  and  it'is  kept  up  by  the 
draught  of  air  from  the  vault. 

The  most  important  part,  however,  of 
the  apparatus  of  the  glass-house  is  the 
crucible,  made  from  clay,  found  at  Stour- 
bridge. This  is  first  pounded  fine,  then 
sifted,  moistened,  and  worked  into  a 
thick  dough.  Sometimes  old  crucibles 
are  used,  which  are  broken  into  powder, 
and  then  mixed  with  a  red  clay.  Some 
pots,  for  bottle  and  flint  glass,  are  made 


40  inches  deep  and  wide.  They  are  from 
2  to  4  inches  in  thickness.  They  remain 
several  days  at  a  white  heat,  before  they 
are  placed  in  the  furnace. 

The  basis  of  glass  is  silica.  When 
flints  or  quartz  are  used,  they  are  first 
reduced  to  powder  by  being  heated  red 
hot,  and  then  plunged  into  cold  water. 
This  causes  them  to  whiten  and  fall  to 
pieces,  after  which  they  are  ground  and 
sifted.  The  second  ingredient  is  potash 
or  soda.  The  alkali  used  is  more  or  less 
pure,  according  to  the  fineness  of  the 
glass  to  be  made.  Lime  is  often  em- 
ployed in  small  quantities  ;  also  borax. 

Of  the  metallic  oxides  added  in  dif- 
ferent cases,  the  deutoxide  of  lead  is  the 
most  common.  It  renders  flint  glass  more 
fusible,  heavy,  and  tough,  more  easy  to 
be  ground  and  cut,  and  increases  its  bril- 
liancy and  refractive  power. 

A  small  quantity  of  black  oxide  of  man- 
ganese renders  the  glass  more  transpa- 
rent ;  too  much  gives  a  purple  tinge, 
which,  however,  may  be  destroyed  by  a 
little  charcoal  or  wood. 

Arsenious  acid  (white  arsenic),  in  small 
quantities,  promotes  the  clearness  of 
glass ;  too  much  of  it  gives  the  glass  a 
milky  whiteness.  Its  use  in  drinkiug- 
vessels  is  not  free  from  danger,  if  the 
glass  contains  so  much  alkali  that  any 
part  is  soluble  in  acids. 

The  various  materials  are  carefully 
washed,  and,  after  the  extraction  of  all 
the  impurities,  are  conveyed  to  the  fur- 
nace in  pots  made  of  tobacco-pipe  clay. 
The  produce  of  this  process  is  called  the 
frit,  which  is  again  melted  in  large  pots 
'or  crucibles,  till  the  whole  mass  becomes 
beautifully  clear,  and  the  dross  rises  to 
the  top. 

Blmoing  is  the  next  process,  which,  in 
round  glass,  as  phials,  drinking-glasses, 
&c,  is  thus  performed ; — The  workmen 
dip  the  end  of  long  iron  pipes,  red  hot, 
into  the  liquid  glass,  then  roll  it  on  a 
polished  iron  plate  to  give  it  an  external 
even  surface  ;  they  next  blow  down  the 
iron  pipe,  till  it  enlarges  the  metal  like  a 
bladder,  and,  if  necessary,  roll  it  again 
on  the  iron  plate,  and  proceed  to  form  it 
into  a  globular  form,  or  any  other  one 
required.  The  glass  is  then  transferred 
from  the  blowing-pipe,  by  dipping  the 
end  of  another  iron  rod  into  the  liquid 
glass,  which  adheres  to  the  heated  rod, 
and  with  which  the  workman  sticks  it  to 
the  bottom  of  the  vessel ;  then,  with  a 
pair  of  pincers,  wetted  with  water,  he 
touches  the  neck,  which  immediately 
cracks,   and,   on  being  slightly  struck, 


a  la] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


215 


separates  at  the  end  of  the  blowing-pipe, 
and  becomes  attached  to  the  iron  rod.  ; 
The  vessel  is  next  carried  up  to  the 
mouth  of  the  furnace,  to  be  heated  and 
softened,  that  the  operator  may  finish  it. 
If  the  vessel  require  a  handle,  the  opera- 
tor forms  it  separately,  and  unites  it  while 
melting  hot,  forming  it  with  pincers  to 
the  requisite  shape  and  pattern. 

Annealing  is  the  removing  of  the  glass, 
after  it  has  been  blown  or  cast,  into  a 
furnace,  whose  heat  is  not  sufficiently 
intense  to  melt  it ;  and  gradually  with- 
drawing the  article  from  the  hottest  to  a 
cooler  part  of  the  annealing  chamber,  till 
it  is  cold  enough  to  be  taken  out  for  use. 
If  cooled  too  suddenly,  it  is  extremely 
brittle. 

Coloring. — The  different  colored  glasses 
owe  their  tints  to  the  different  metallic 
oxides  mixed  with  the  materials  while  in 
a  state  of  fusion.  In  this  manner  are 
made  those  elegant  pastes,  which  so  faith- 
fully imitate,  and  not  unfrequently  excel, . 
in  brilliancy,  their  originals,  the  gems  of 
antiquity.  The  glass,  however,  for  this 
purpose  is  preserved  in  a  peculiar  man- 
ner, and  requires  great  nicety.  It  com- 
bines purity  and  durability. 

Opaque  glass  is  made  by  the  addition 
of  the  oxide  of  tin,  and  produces  that 
beautiful  imitation  of  enamel  which  is  so 
much  admired.  Dials  for  watches  and 
clocks  are  thus  made. 

Bottle-glass  is  made  of  soap-boilers' 
waste  and  river  sand,  or  sand  and  lime 
with  clay  and  salt,  mixed,  evaporated, 
and  fritted.  Common  window-glass,  of  2 
soap  waste,  1  kelp,  and  1  sand.  Super 
window-glass,  25  sand,  12  sulphate  of 
soda,  or  Glauber's  salt,  4  carbonate  of 
lime,  or  lime  unburnt,  and  1  of  charcoal ; 
or  2  purified  sand,  3  strong  kelp.  Plate, 
or  sodaic  glass,  is  sand  100,  sub-carbonate 
of  soda  55,  unslaked  lime  9,  nitre  4,  and 
powdered  glass  60.  The  product  is  three- 
fourths.  Flint,  or  litharge  glass,  is  10  fine 
sand,  6  red  lead,  3  pearlash,  a  half  part 
oxide  of  manganese. 

Grinding  and  polishing  give  plate-glass 
a  fine  lustre.  The  grinder  takes  it  rough 
out  of  the  hands  of  the  caster,  and,  lay- 
ing it  upon  a  stone  table,  to  which  it  is 
fixed  with  stucco,  he  lays  another  rough 
glass,  half  the  size  of  the  former,  upon 
it.  To  the  smaller  glass  a  plank  is  fast- 
ened, by  means  of  stucco,  and  to  the 
whole  a  wheel,  made  of  hard,  light  wood, 
about  six  inches  in  diameter,  by  the  pul- 
ling of  which  from  side  to  side,  and  from 
end  to  end,  of  the  glass,  a  constant  at- 
trition  is  kept   up ;    and,   by  allowing 


water  and  fine  Band  to  pass  between  the 
plates,  the  whole  is  very  finely  polished ; 
but,  to  give  the  finishing  polish,  powder 
of  smalt  is  used.  As  the  upper  glass 
grows  smoother,  it  is  taken  away,  and  a 
rougher  one  substituted  in  its  stead ;  and 
so  on  till  the  work  is  done.  Except  in 
the  very  largest  plates,    the  workmen 

Eolish  their  glass  by  means  of  a  plank, 
aving  four  wooden  handles  to  move  it ; 
and  to  this  plank  a  plate  of  glass  is  ce- 
mented, as  above. 

Various  ornamental  fo?'ms  are  given 
to  the  surface  of  glass  vessels  by  metallic 
moulds.  The  mould  is  usually  of  cop- 
per, with  the  figure  cut  on  its  inside,  and 
opens  with  hinges  to  permit  the  glass  to 
be  taken  out.  The  mould  is  filled  by  a 
workman,  who  blows  fluid  glass  into  its 
top.  The  chilling  of  the  glass,  when  it 
comes  in  contact  with  the  mould,  im- 
pairs its  ductility,  and  prevents  the  im- 
Sression  of  the  figure  from  being  sharp, 
ome  moulds,  however,  are  made  in 
parts,  which  can  be  suddenly  brought 
together  on  the  inside  and  outside  of  the 
glass  vessel,  and  produce  specimens 
nearly  equal  to  cut  glass. 

Cut  glass,  so  called,  is  produced  by 
grinding  the  surface  with  small  wheels 
of  stone,  metal,  or  wood.  The  glass  is 
held  to  the  surface  of  the  wheels.  The 
first  cutting  is  with  wheels  of  stone ;  then 
with  iron,  covered  with  sharp  sand  or 
emery ;  and,  finally,  with  brush  wheels, 
covered  with  putty.  A  small  stream  of 
water  is  kept  continually  running  on  the 
glass,  to  prevent  the  friction  from  excit- 
ing too  much  heat. 

Glass  may  be  ground  on  any  coarse 
grained  stone,  with  sand,  or  emery  and 
water.  Flat  pieces  of  glass  may  be  di- 
vided in  any  shape,  by  making  a  notch 
with  a  file,  and  carrying  a  piece  of  hot 
charcoal  before  the  line  in  which  it  is  in- 
tended the  fracture  should  proceed.  The 
charcoal  must  be  kept  aiive  with  the 
breath,  and  the  progress  humored  by 
experience.  Tubes,  &c,  are  cut  with  a 
file  all  round,  and  then  broken. 

GLASS  COLOKING.  Mr.  G.  Bon- 
temps  has  shown  that  all  the  colors  of 
the  prismatic  spectrum  might  be  given 
to  glass  by  the  use  of  the  oxide  of  iron 
in  varying  proportions  and  by  the  agency 
of  different  degrees  of  heat ;  and  that  all 
the  colors  are  produced  in  their  natural 
disposition  in  proportion  as  you  increase 
the  temperature.  Similar  phenomena 
were  observed  with  the  oxide  of  manga- 
nese. Manganese  is  employed  to  give  a 
pink  or  purple  tint  to  glass,  and  also  to 


216 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[gla 


neutralize  the  slight  green  given  by  iron 
and  carbon  to  glass  in  its  manufacture. 
If  the  glass  colored  by  manganese  re- 
mains too  long  in  the  melting-pot  or  the 
annealing-kiln,  the  purple  tint  turns  first 
to  a  light  brownish  red,  then  to  a  yellow, 
and  afterwards  to  green.  White  glass 
in  which  a  small  proportion  of  manga- 
nese has  been  used  is  liable  to  become 
light  yellow  by  exposure  to  luminous 
power.  This  oxide  is  also  in  certain 
window-glass  disposed  to  turn  pink  or 
purple  under  the  action  of  the  sun's 
rays. 

M.  Bontemps  has  found  that  similar 
changes  take  place  in  the  annealing  oven. 
He  has  determined,  by  experiments  made 
by  him  on  polygonal  lenses  for  M.  Fres- 
nel,  that  light  is  the  agent  producing  the 
change  mentioned  •  and  the  author  ex- 
presses a  doubt  whether  any  change  in 
the  oxidization  of  the  metal  will  explain 
the  photogenic  effect.  A  series  of  chro- 
matic changes  of  a  similar  character 
were  observed  with  the  oxides  of  cop- 
per ;  the  colors  being  in  like  manner 
regulated  by  the  heat  to  which  glass  was 
exposed.  It  was  found  that  silver,  al- 
though with  less  intensity,  exhibited  the 
same  phenomena;  and  gold,  although 
usually  employed  for  the  purpose  of  im- 
parting varieties  of  red,  was  found  by 
varying  degrees  of  heating  at  a  high 
temperature  and  recasting  several  times 
to  give  a  great  many  tints,  varying  from 
blue  to  pink,  red,  opaque  yellow,  and 
green.  Charcoal  in  excess  in  a  mixture 
of  silico  alkaline  glass  gives  a  yellow 
color,  which  is  not  so  bright  as  the  yel- 
low from  silver,  and  this  yellow  color 
may  be  turned  to  a  dark  red  by  a  second 
fire.  Mr.  B.  is  disposed  to  refer  these 
chromatic  changes  to  some  modifications 
of  the  composing  particles  rather  than  to 
any  chemical  changes  in  the  materials 
employed. 

GLAZIER'S  PUTTY.  Whiting  and 
linseed  drying  oil,  beaten  together  some 
time. 

GLAZING  EARTHENWARE  AND 
PORCELAIN.  In  the  bisquet  state, 
earthenware  and  porcelain  will  adhere  to 
the  tongue,  and  imbibe  moisture.  The 
tendency  of  the  earths  to  absorb  water  is 
the  cause;  and  the  ware  in  this  state 
would  not  retain  water  and  many  other 
liquids.  Hence,  there  is  necessity  for  an 
artificial  vitrified  covering,  whose  com- 
ponents are  so  adapted  to  those  of  the 
body  as  to  be  equally  affected  with  them 
by  change  of  temperature,  and  preserve 
equality  of  expansion  or  contraction. 


We  have  not  yet  discovered  a  body 
and  glaze  that  will  be  complete  ware  by 
once  baking.  The  components  of  the 
present  bodies  do  not  sufficiently  eon- 
glomerate  to  remain  unaffected  by  the 
moisture  of  the  glaze,  but  the  articles 
become  soft,  and  either  shrink,  or  alter 
their  figure.  The  only  probable  sugges- 
tion towards  this  is: — Grind  very  well 
some  of  the  flesh-colored  feldspar  from 
Montgomeryshire,  precipitate  whatever 
iron  may  be  in  the  mineral,  then  add  8 
per  cent,  of  ground  native  carbonate  of 
barytes,  and  1  per  cent,  of  cobalt  blue 
calx  ;  mix  in  water  for  dip  and  glaze,  and 
fire  only  once.  Feldspar  is  the  glaze  of 
Nankin  porcelain. 

The  manufacturers  have  their  particu- 
lar glazes,  for  certain  bodies.  The  several 
components  are  carefully  proportioned, 
then  ground  to  a  pulpy  state,  almost  im- 
palpable between  the  thumb  and  finger ; 
this  is  mixed  with  a  certain  quantity  of 
water,  and  kept  agitated  to  preserve  uni- 
form suspension.  The  dipper  places 
nigh  him  a  board  covered  with  bisquet 
ware,  and  another  with  a  number  of 
small  pegs  or  nails.  He  immerses  (or 
dips)  each  article,  with  a  suitable  motion 
to  cover  the  whole,  then  places  it  on  the 
pegs  to  drain.  The  water  is  imbibed  by 
the  pores  of  the  ware,  and,  to  the  thick- 
ness of  writing  paper,  the  components 
form  a  covering,  which  is  vitrified  by 
baking.  From  the  pegs  the  vessel  is 
placed  in  a  sagger,  and  at  a  lower  heat  of 
the  oven  the  whole  glaze  is  fused. 

The  following  are  excellent  glazes  : 

Fob  Porcelain. — Pulverize  well,  and 
carefully  fuse  together,  flint  20  parts, 
cullet  7,  Cornish-stone  20,  red  lead  20, 
borax  20,  subcarbonate  of  soda  7,  nitrate 
of  potash  3,  oxide  of  tin  24-,  cobalt  calx  1. 
Or, 

Fuse  together,  flint  glass  66  parts,  red 
lead  15,  arsenic  7,  muriate  of  soda  5,  ni- 
trate of  potash  6,  cobalt  calx  1.  When 
well  ground,  mix  with  Cornish-stone  40 
parts,  frit  (as  above)  18  parts,  flint  12 
parts,  and  white  lead  30:  grind  in  the 
glaze  mill,  and  use  carefully. 

Fuse  together  Cornish-stone  80  parts, 
soda  20;  pulverize,  and  grind  together, 
for  use.  The  fritt  40  parts,  flint  16,  Cor- 
nish stone  24,  and  white  lead  20. 

Fuse  together,  cullet  85  parts,  flint  10, 
white  lead  2,  arsenic  1,  nitrate  of  potash 
2;  then  grind  together,  fritt  30  parts, 
Cornish  -  stone  40,  flint  25,  boracio 
acid  5. 

The  feldspar  glazes  are  subjoined  for 
general  purposes  of  utility.     They  are 


GLU] 


CYCLOPEDIA    OF    THE    USEUL    ARTS. 


21V 


most  secretly  preserved  by  their  first  em- 
ployers, but  it  is  well  they  be  exten- 
sively known. 

Fuse  together,  feldspar  66  parts,  borate 
of  soda  34 ;  then  grind,  and  mix  with 
flint  95,  nitrate  of  potash  5,  ground  for 
use. 

Or,  feldspar  60,  borax  40,  fused,  and 
mixed  with  flint  50,  potash  2. 

Or,  feldspar  90,  carb.  barytes  7,  lime 
2,  magnesia  1 ;  and  mixed  with  flint  67, 
borax  30,  and  potash  3. 

Or,  feldspar  60,  borax  24,  nitre  6,  salt 
4,  and  potash  6,  mixed  with  flint  60. 

Raw  glazes. — White  lead  45,  Cornish- 
stone  22,  cullet  22,  flint  8,  borax  2,  salt  1. 

Or,  white  lead  51,  Cornish-stone  25, 
cullet  11,  flint  12,  carb.  potash  1. 

Or,  white  lead  49,  Cornish-stone  24, 
cullet  10,  flint  14,  borax  3. 

Or,  white  lead  42,  Cornish-stone  27, 
cullet  14,  flint  11,  bor.  acid  6. 

GLAZING  IRON  VESSELS.  The 
iron  vessels  are  cleaned  perfectly  in  weak 
sulphuric  acid,  then  washed  well  in  soft 
cold  water,  and.  dipped  into  a  thin  paste 
made  with  quartz  melted  with  borax, 
feldspar,  and  clay  free  from  iron,  reduced 
into  an  impalpable  powder  with  sufficient 
water  to  make  it  into  a  thin  paste.  After 
the  vessels  are  dipped  in  this  paste,  or 
the  said  paste  laid  on  with  a  brush,  they 
are  powdered  in  the  inside  with  a  linen 
bag  containing  a  very  finely  pulverized 
mixture  of  feldspar,  carbonate  of  soda, 
borax,  and  a  little  oxide  of  tin.  They 
are  then  left  to  dry  for  some  time  in  a 
clean  place,  and  then  heated  in  an  enam- 
elling furnace.  This  coating  is  very 
white,  and  resists  the  action  of  heat, 
acids,  and  alkalies.  The  great  defect  in 
coating  iron  vessels,  for  cooking,  or  to 
be  used  and  exposed  to  great  changes  of 
heat  and  cold,  is  the  expansion  and  con- 
traction of  the  metal,  which  soon  scales 
off  the  glazial  coverings. 

GLASS  PAINTING.  In  Painting, 
the  method  of  staining  glass  in  such  a 
manner  as  to  produce  the  effect  of  repre- 
senting all  the  subjects  whereof  the  art 
is  susceptible.  A  French  painter  of  Mar- 
seilles is  said  to  have  been  the  first  who 
instructed  the  Italians  in  this  art,  during 
the  pontificate  of  Julius  II.  It  was,  how- 
ever, practised  to  a  considerable  extent  by 
Lucas  of  Leyden,  and  Albert  Durer.  The 
different  colors  are  prepared  as  follows  : 
Black  is  composed  of  two-thirds  of  iron 
scales  or  flakes,  and  the  other  third  of 
small  glass  beads,  or  a  substance  called 
roccaqlla  by  the  Italians.  White  is  pre- 
pared from  sand,  or  small  white  pebbles, 
10 


calcined,  pounded,  and  then  grouud 
finely  ;  one  fourth  part  of  saltpetre  is  ad- 
ded, and  the  mixture  is  then  again  cal- 
cined and  pulverized  :  when  dyed,  a  lit- 
tle gypsum  or  plaster  of  Paris  is  added. 
Yetuno  is  formed  from  leaf  silver  ground 
and  mixed  in  a  crucible  with  saltpetre 
or  sulphur ;  then  ground  on  a  porphyry 
stone;  and,  lastly,  ground  over  again 
with  nine  times  the  quantity  of  red 
ochre.  Red,  one  of  the  most  difficult  of 
the  colors  to  make,  is  prepared  of  li- 
tharge of  silver  and  iron  scales,  gum  Ara- 
bic, ferretta,  glass  beads,  and  bloodstone, 
in  nearly  equal  quantities.  Experience 
alone  will  command  success  in  making 
this  color.  Green  is  formed  from  ces 
ustum  one  ounce,  the  same  quantity  of 
black  lead,  and  four  ounces  of  white  lead, 
incorporated  by  the  action  of  fire.  When 
calcined  a  fourth  part  of  saltpetre  is  ad- 
ded, and  after  a  second  calcination  a  sixth 
part  more  ;  after  which  a  third  coction  is 
made  before  using  it.  Azure,  purple, 
and  violet  are  prepared  in  a  similar  man- 
ner to  green,  omitting  the  ass  ustum, 
and  in  its  stead  using  sulphur  for  azure, 
perigneux  for  purple,  and  both  these 
drugs  for  violet.  Carnations  are  com- 
pounded colors,  are  calcined,  and  mostly 
mixed  with  water,  and  must  be  finished 
part  by  part,  and  each  with  great  dis- 
patch, before  the  plaster  dries,  and  there 
is  little  opportunity  for  blending.  The 
lights  cannot  be  heightened;  but  the 
shadows  may,  when  they  begin  to  dry, 
be  a  little  strengthened.  Promptitude 
and  facility  in  execution  are  the  great 
requisites  for  this  method  of  painting. 

GLAUBEE'S  SALT.  Sulphate  o?  so- 
da, originally  made  by  Glauber,  in  his 
process  for  obtaining  muriatic  acid,  by 
distilling  a  mixture  of  common  salt  and 
sulphuric  acid. 

GLAUCOLITE.  (Gr.  yUvKos,  blue.) 
A  mineral  of  a  bluish  green  color,  found 
near  the  lake  Baikal,  in  Siberia ;  it  is  a 
silicate  of  alumina  and  lime. 

GLUCINA.  One  of  the  primitive 
earths,  originally  discovered  by  Vauque- 
lin,  in  the  beryl  and  emerald.  It  may  be 
extracted  from  either  of  these  minerals, 
by  treating  their  powder  successively 
with  potash,  with  water,  and  with  muri- 
atic acid.  The  solution  by  the  latter, 
being  evaporated  to  d^-ness,  is  to  be  di- 
gested with  water,  and  filtered.  On 
pouring  carbonate  of  ammonia  in  excess 
into  the  liquid,  we  form  soluble  muriate 
of  ammonia,  with  insoluble  carbonates  of 
lime,  chrome,  and  iron,  as  also  carbon- 
ate of  glucina,  which  may  be  dissolved. 


218 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


b 


out  from  the  rest  by  an  excess  of  carbon- 
ate of  ammonia.  When  the  liquid  is  fil- 
tered anew,  the  glucina  passes  through, 
and  may  be  precipitated  in  the  state  of  a 
carbonate  by  boiling  the  liquid,  which 
expels  the  excess  of  ammonia.  By  wash- 
ing, drying,  and  calcining  the  carbonate, 
pure  glucina  is  obtained.  It  is  a  white 
insipid  powder,  infusible  in  the  heat  of 
a  smith's  forge,  insoluble  in  water,  but 
soluble  in  caustic  potash  and  soda ;  as  al- 
so, especially  when  it  is  a  hydrate,  in 
carbonate  of  ammonia.  It  has  a  metallic 
base  called  glueinum,  of  which  100  parts 
combine  with  45-252  of  oxygen  to  form 
the  earth.  It  is  too -rare  to  be  susceptible 
of  application  in  manufactures. 

GLUE  is  the  chemical  substance  gela- 
tine in  a  dry  state.  The  preparation  and 
preservation  of  the  skin  and  other  animal 
matters  employed  in  the  manufacture 
of  glue,  constitute  a  peculiar  branch  of  in- 
dustry. Those  who  exercise  it  should 
study  to  prevent  the  fermentation  of  the 
substances,  and  to  diminish  the  cost  of 
carriage  by  depriving  them  of  as  much 
water  as  can  conveniently  be  done.  They 
may  then  be  put  in  preparation  by  mace- 
rating them  in  mine  of  lime,  renewed 
three  or  four  times  in  the  course  of  a 
fortnight  or  three  weeks.  This  process 
is  performed  in  large  tanks  of  masonry. 
They  are  next  taken  out  with  all  the  ad- 
hering lime,  and  laid  in  a  layer,  2  or  8 
inches  thick,  to  drain  and  dry,  upon  a 
sloping  pavement,  where  they  are  turned 
over  by  pronsrs  two  or  three  times  a  day. 
The  action  of  the  lime  dissolves  the  blood 
and  certain  soft  parts,  attacks  the  epider- 
mis, and  disposes  the  gelatinous  matter 
to  dissolve  more  readily.  When  the 
cleansed  matters  are  drieel,  they  may  be 
packed  in  sacks  or  hogsheads,  and  trans- 

Sorted  to  the  glue  manufactory  at  any 
istance.  The  principal  substances  of 
which  slue  is  made  are  the  parings  of  ox 
and  other  thick  hides,  which  form  the 
strongest  article ;  the  refuse  of  the  lea- 
ther-dresser;  both  afford  from  45  to  55 
per  cent,  of  glue.  The  tendons,  and 
many  other  offals  of  slauorhter-houses, 
also  afford  materials,  though  of  an  inferi- 
or quality,  for  the  purpose.  The  refuse 
of  tanneries,  such  as  the  ears  of  oxen, 
calves,  sheep,  &c,  are  better  articles ; 
but  parings  of  parchment;  old  gloves, 
and,  m  fact,  animal  skin,  in  every  form, 
uncombined  with  tannin,  may  be  made 
into  glue. 

These  various  matters  aTc  first  rinsed, 
then  drained,  and  afterwards  boiled  in 
large  shallow  copper  vessels  for  some 


hours,  during  which  they  are  well  stir- 
red. 

The  solution  must  be  drawn  off  in  suc- 
cessive portions  ;  a  method  which  frac- 
tions the  products,  or  subdivides  them 
into  articles  of  various  value,  gradually 
decreasing  from  the  first  portion  drawn 
off  to  the  last.  It  has  been  ascertained 
by  careful  experiments  that  gelatine  gets 
altered  over  the  fire  very  soon  after  it  is 
dissolved,  and  it  ought  therefore  to  be 
drawn  off  whenever  it  is  sufficiently  fluid 
and  strong  for  forming  a  clear  gelatinous 
mass  on  cooling,  capable  of  being  cut  in- 
to moderately  firm  slices  by  the  wire. 
This  point  is  commonly  determined  by 
filling  half  an  egg-shell  with  the  liquor, 
and  exposing  it  to  the  air  to  cool.  The 
jelly  ought  to  get  very  consistent  in  the 
course  of  a  few  minutes  ;  if  not  so,  the 
boiling  must  be  persisted  in  a  little  long- 
er. When  this  term  is  attained,  the  fire 
is  smothered  up,  and  the  contents  of  the 
boiler  are  left  to  settle  for  a  quarter  of  an 
hour.  The  stop-cock  being  partially 
turned,  all  the  thin  gelatinous  liquor  is 
run  off  into  a  deep  boiler,  immersed  in  a 
warm  water  bath,  so  that  it  may  continue 
hot  and  fluid  for  several  hours.  At  the 
end  of  this  time,  the  supernatant  clear 
liquid  is  to  be  drawn  off  into  con- 
gealing boxes,  in  which  the  solution  as  it 
"cools  into  a  jelly  takes  the  shape  of  the 
space.  It  is  then  exposed  to  the  air,  or  a 
stove  heat,  to  dry,  and  receives  a  gloss  by 
being  dipped  in  water  and  brushed.  It 
is  finally  dried,  and  rendered  fit  for  pack- 
ing. 

GLUTEN  was  first  extracted  by  Bec- 
caria  from  wheat  flour,  and  was  long  re- 
garded as  a  proximate  principle  of  plants, 
till  Einhof,  Taddei,  and  Berzelius,  suc- 
ceeded in  showing  that  it  may  be  re- 
solved by  means  of  alcohol  "into  three 
different  substances,  one  of  which  re- 
sembles closely  animal  albumine,  and  has 
been  called  Zymome,  or  vegetable  albu- 
mine ;  another  has  been  called  Gliadine; 
and  a  third,  Murine.  The  mode  of  sepa- 
rating gluten  from  the  other  constituents 
of  wheat  flour  has  boen  described  to- 
wards the  end  of  the  article  Brkad. 

Gluten,  when  dried  in  the  air  or  a 
stove,  diminishes  greatly  in  size,  becomes 
hard,  brittle,  glistening,  and  of  a  deep 
yellow  color.  It  is  insoluble  in  ether, 
in  fat,  and  essential  oils,  and  nearly  so  in 
water.  Alcohol  and  acetic  acid  cause 
gluten  to  swell  and  make  a  sort  of  milky 
solution.  Dilute  acids  and  alkaline  leys 
dissolve  gluten.  Its  ultimate  constitu- 
ents are  not  determined,  but  azote  is  one 


gol] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


219 


of  them,  and  accordingly  when  moist  glu- 
ten is  left  to  ferment,  it  exhales  the  smell 
of  old  cheese. 

GLYCERINE  is  a  sweet  substance 
which  may  be  extracted  from  fatty  sub- 
stances. If  we  take  equal  parts  of  olive 
oil  and  finely-ground  litharge,  put  them 
into  a  basin  with  a  little  water,  set  this 
on  a  sand  bath  moderately  heated,  and 
stir  the  mixture  constantly,  with  the  oc- 
casional addition  of  hot  water  to  replace 
what  is  lost  by  evaporation,  we  shall  ob- 
tain in  a  short  time  a  soap  or  plaster  of 
lead.  After  having  added  more  water  to 
this,  we  remove  the  vessel  from  the  fire, 
decant  the  liquor,  filter  it,  pass  sulphur- 
eted  hydrogen  through  it  to  separate  the 
lead,  then  filter  afresh,  and  concentrate 
the  liquor  as  much  as  is  possible  without 
burning  upon  the  sand  bath.  What  re- 
mains must  be  finally  evaporated  within 
the  receiver  of  the  air-pump.  Glycerine 
thus  prepared  is  a  transparent  liquid, 
without  color  and  smell,  and  of  a  sirupy 
consistence.  It  has  a  very  sweet  taste. 
Its  specific  gravity  is  1*27  at  the  tempera- 
ture of  60°.  When  thrown  upon  burn- 
ing coals,  it  takes  fire  and  burns  like  an 
oil.  Water  combines  with  it  in  almost  all 
proportions  ;  alcohol  dissolves  it  readily ; 
nitric  acid  converts  it  into  oxalic  acid ; 
and  according  to  Vogel,  sulphuric  acid 
transforms  it  into  sugar,  in  the  same  way 
as  it  does  starch.  Ferment  or  yeast  does 
not  affect  it  in  any  degree. 

Its  constituents  are,  carbon,  40 ;  hydro- 
gen, 9  ;  oxygen,  51 ;  in  100. 

GNEISS  is  the  name  of  one  of  the 
great  mountain  formations,  being  reck- 
oned the  oldest  of  the  stratified  rocks. 
It  is  composed  of  the  same  substances  as 

franite,  viz. :  quartz,  mica,  and  feldspar. 
n  gneiss,  however,  they  arc  not  in  gran- 
ular crystals,  but  in  scales,  so  as  to  give 
the  mass  a  slaty  structure.  It  abounds 
in  metallic  treasures. 

GOLD.  This  metal  is  distinguished 
by  its  splendid  yellow  color;  its  great 
density  =  19*3,  compared  to  water  1*0  ;  its 
fusibility  at  the  32d  degree  of  Wedge- 
wood's  pyrometer ;  its  pre-eminent  duc- 
tility and  malleability,  whence  it  can  be 
beat  into  leaves  only  one  282,000th  of  an 
inch  thick ;  and  its  insolubility  in  any 
acid  menstruum,  except  the  mixture  of 
muriatic  and  nitric  acids,  styled  by  the 
alchymists  aqua  regria,  because  gold  was 
deemed  by  them  to  be  the  king  of  me- 
tals. 

Gold  is  found  only  in  the  metallic 
state,  sometimes  crystallized  in  the  cube, 
and  its  derivative  forms.    It  occurs  also 


in  threads  of  various  size,  twisted  and  in- 
terlaced into  a  chain  of  minute  octahedral 
crystals ;  as  also  in  spangles  or  roundish 
grains,  which,  when  of  a  certain  magni- 
tude, are  called  pepitas.  The  small  grains 
are  not  fragments  broken  from  a  greater 
mass  ;  but  they  show  by  their  flattened 
ovoid  shape,  and  their  rounded  outline, 
that  this  is  their  original  state.  The 
spec.  grav.  of  native  gold  varies  from  13-3 
to  17*7.  Humboldt  states  that  the  larg- 
est peplta  known  was  one  found  in  Peru, 
weighing  about  12  kilogrammes  (26£  lbs. 
avoird.) ;  but  masses  have  been  quoted 
in  the  province  of  Quito  which  weighed 
nearly  four  times  as  much. 

It  is  scattered  over  the  whole  globe  in 
primary  geological  districts  ;  in  the  moun- 
tains of  Wicklow  in  Ireland;  in  Lead- 
hills,  Scotland,  and  parts  of  Wales.  In 
France,  in  the  Valley  of  Oyseens,  there 
is  a  vein  of  gold  in  quartz.  Its  aurife- 
rous rivers  are  numerous.  The  Rhone, 
near  Geneva,  the  Rhine,  near  Strasbourg, 
the  Salat,  Garonne,  and  the  Herrault. 
The  gold  mines  of  Piedmont  are  still 
worked.  It  is  worked  at  Salzbourg,  in 
Germany,  and  also  in  Hungary  and 
Transylvania.  The  Asiatic  Ural  chain 
contains  many  gold  mines  ;  Africa  pos- 
sesses large  auriferous  deposits,  chiefly 
alluvial.  In  South  America,  Brazil,  Chi- 
li, Peru,  and  Colombia,  furnish  produc- 
tive quantities  of  gold.  It  is  found  in 
Canada,  Maine,  Virginia,  North  and 
South  Carolina,  and  California,  in  this 
continent.  Along  the  Sierra  Nevada,  in 
this  latter  state,^  are  found  the  chief  sites 
of  the  gold  diffused  through  the  quartz 
mass.  Along  the  Yuba,  Trinity,  San  Jo- 
achim, Sacramento,  and  San  Francisco 
rivers,  numerous  rich  placers  have  been 
found  in  the  beds  of  the  streams.  There 
seems  to  be  no  limit  to  the  extent  of  the 
quantity  of  gold  diffused  through  the 
granitic  rocks  of  this  district,  from  which 
by  attrition  the  streams  have  derived 
their  gold.  At  Trinity  Bluffs,  the  gold 
scales  are  found  mixed  with  Basaltic 
sand,  which  so  envelops  and  protects 
the  gold  that  it  is  difficult  to  separate  and 
purify  the  metal. 

Auriferous  sands  require  little  treat- 
ment to  separate  the  gold.  The  sands  are 
washed  on  a  rocking  table,  and  after- 
wards in  wooden  bowls  by  hand.  Amal- 
gamation is  employed  to  carry  off  from 
the  sand  the  lighter  particles  of  gold: 
much  of  the  California  gold  is  obtained 
in  this  way.  In  some  places  the  sand  is 
so  heavy  as  not  to  allow  the  particles  of 
gold  to  be  separated,  nor  can  acids  bo 


220 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[goi 


used,  as  lime  and  iron  are  present ;  solu- 
tion of  chlorine  from  chloride  of  lime  has 
been  found  to  separate  the  gold  ef- 
fectually. In  South  Carolina  the  plan 
adopted  is  this : — The  ore  is  crushed  by 
huge  rotating  iron  rollers,  during  which 
a  gentle  fall  of  water  carries  the  metal,  as 
fast  as  it  is  pulverized,  through  a  small 
aperture  into  a  narrow  trough,  across 
which,  at  intervals,  is  a  deposit  of  mer- 
cury. The  trough  is  slightly  inclined,  by 
rhich  means  the  sand  passes  out  freely 
ndiile  the  gold  adheres  to  the  quicksilver. 
A.t  the  close  of  the  day  this  mercury, 
«rith  the  gold  attached,  is  all  taken  out, 
ind  by  a  simple  process  called  "  pan- 
ning," the  metals  are  neatly  separated. 
The  mercury  is  bottled  for  re-use,  and 
the  gold  is  burned  to  eradicate  the  few 
particles  of  mercury  which  still  adhere 
to  it. 

The  other  ores  are  metallic  sulphurets. 
as  those  of  copper,  silver,  arsenic,  ana 
iron.  The  following  is  an  outline  of  the 
treatment  of  these : — The  stony  ores  are 
first  ground  in  the  stamping  mill,  and 
then  washed  in  hand-basins,  or  on  wood- 
en tables. 

The  auriferous  sulphurets  are  much 
more  common,  but  much  poorer  than  the 
former  ores ;  some  contain  only  one 
200,000th  part  of  gold,  and  yet  they  may 
be  worked  with  advantage,  when  treated 
with  skill  and  economy. 

The  gold  of  these  ores  is  separated  by 
two  different  processes;  namely,  by  fu- 
sion and  amalgamation. 

The  auriferous  metallic  sulphurets  are 
first  roasted ;  then  melted  into  mattes, 
which  are  roasted  anew ;  next  fused 
with  lead,  whence  an  auriferous  lead  is 
obtained,  which  may  be  refined  by  the 
process  of  cupellation. 

When  the  gold  ores  are  very  rich,  they 
are  melted  directly  with  lead,  without 
preliminary  calcination  or  fusion.  These 
processes  are,  however,  little  practised, 
because  they  are  less  economical  and  cer- 
tain than  amalgamation,  especially  when 
the  gold  ores  are  very  poor. 

If  these  ores  consist  of  copper  pyrites, 
and  if  their  treatment  has  been  pushed  to 
the  point  of  obtaining  auriferous  rose 
copper,  or  even  black  copper  including 
gold,  the  precious  metal  cannot  be  sepa- 
rated by  the  process  of  liquation,  becauso 
the  gold,  having  more  affinity  for  copper 
than  for  lead,  can  be  but  partially  run  off 
by  the  latter  metal.  For  these  reasons 
the  process  of  amalgamation  is  far  prefera- 
able. 

This  process  being  the  same  for  silver, 


its  description  is  reserved  for  that  me- 
tal. The  rich  ores  in  which  the  na- 
tive gold  is  apparent,  and  merely  dissem- 
inated in  a  stony  gangue,  are  directly  tri- 
turated with  quicksilver,  without  any 
preparatory  operation.  As  to  the  poor 
ores,  in  which  the  gold  seems  lost  amid 
a  great  mass  of  iron,  sulphuret  of  copper, 
&c,  they  are  subjected  to  a  roasting  be- 
fore being  amalgamated.  This  process 
seems  requisite  to  lay  bare  the  gold  en- 
veloped in  the  sulphurets.  The  quick- 
silver with  which  the  ore  is  now  ground, 
seizes  the  whole  of  its  gold,  in  however 
small  quantity  this  metal  may  be  present. 
The  gold  procured  by  the  refining  pro- 
cess with  lead,  is  free  from  copper  and 
lead,  but  it  may  contain  iron,  tin,  or  sil- 
ver. It  cannot  be  separated  from  iron  and 
tin  without  great  difficulty  and  expense, 
if  the  proportion  of  gold  be  too  small 
to  admit  of  the  employment  of  muriatic 
acid. 

By  cupellation  with  lead,  gold  may  be 
deprived  of  any  antimony  united  with  it. 
Tin  gives  gold  a  remarkable  hardness 
and  brittleness, ;  a  piece  of  gold,  exposed 
for  some  time  over  a  bath  of  red-hot  tin, 
becomes  brittle.  The  same  thing  hap- 
pens more  readily  over  antimony,  from 
the  volatility  of  this  metal.  A  2,000th 
part  of  antimony,  bismuth,  or  lead,  de- 
stroys the  ductility  of  gold.  The  tin 
may  be  got  rid  of  by  throwing  some  cor- 
rosive sublimate  or  nitre  into  a  crucible 
containing  the  melted  alloy.  By  the  first 
agent,  perchloride  of  tin  is  volatalized ;  by 
the  second,  stannate  of  potash  forms, 
which  is  carried  off  in  the  resulting  al- 
kaline scoriae. 

Gold  treated  by  the  process  of  amalga- 
mation, contains  commonly  nothing  but 
a  little  silver.  This  silver  is  dissolved 
out  by  nitric  acid,  which  leaves  the  gold 
untouched ;  but  to  make  this  parting 
with  success  and  economy  on  the  great 
scale,  several  precautions  must  be  ob- 
served. 

If  the  gold  do  not  contain  fully  two- 
thirds  of  its  weight  of  silver,  this  metal, 
being  thoroughly  enveloped  by  the  gold, 
is  partially  screened  from  the  action  of  the 
acid.  "Whenever,  therefore,  it  is  known 
by  a  trial  on  a  small  scale,  that  the  silver 
is  much  below  this  proportion,  we  must 
bring  the  alloy  of  gold  and  silver  to  that 
standard  by  adding  the  requisite  quanti- 
ty of  the  latter  metal.  This  process  is 
called  quartation. 

Tins  alloy  is  then  granulated  or  lami- 
nated; and  from  twice  to  thrice  its 
weight  of  sulphuric  or  nitric  acid  is  to  bo 


gol] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


221 


boiled  upon  it ;  and  when  it  is  i 
that  the  solution  has  been  pushed  as~far 
as  possible  by  this  first  acid,  it  is  decant- 
ed, and  new  acid  is  poured  on.  Lastly, 
after  having  washed  the  gold,  some  sul- 
phuric acid  is  to  be  boiled  over  it,  which 
carries  off  a  two  or  three  thousandth  part 
of  silver,  which  nitric  acid  alone  could  not 
dissolve.  Thus  perfectly  pure  gold  is  ob- 
tained. 

The  alloys  of  gold  have  been  examined 
in  detail  by  Mr.  Hatchett.  Of  these  the 
most  important  is  that  used  for  the  gold 
coin  of  England,  commonly  called  stand- 
ard gold,  which  consists  of  eleven  parts 
of  pure  gold  and  one  of  copper  ;  it  is  ex- 
tremely ductile  and  malleable,  but  harder 
than  pure  gold,  and,  therefore,  better 
calculated  to  resist  the  wear  and  tear  of 
circulation.  The  specific  gravity  of  this 
alloy  is  17-157:  20  lbs.  troy  of  it  are  coined 
into  934  sovereigns  and  one  half  sove- 
reign ;  1  lb.  troy,  therefore,  produces 
46  29-40  sovereigns ;  the  same  weight 
was  formerly  coined  into  44  £  guineas. 
The  color  of  this  alloy  is  deeper  yellow 
than  that  of  pure  gold,  and  verges  upon 
orange  :  it  frequently  happens  that  a  part 
of  the  alloy  of  gold  coin  is  silver,  hence 
the  pale  color  of  some  sovereigns  as  com- 
pared with  others.  The  United  States 
^old  contains  an  alloy  of  one-tenth  of  pop- 
per. Among  the  metals  which  destroy 
the  color  and  malleability  of  gold,  none  is 
so  remarkable  as  lead.  It  appears  from 
Mr.  Hatchett's  experiments,  that  when 
lead  forms  about  one  2000th  part  of  the 
alloy,  it  is  too  brittle  for  rolling,  and  that 
the  fumes  of  lead  destroy  the  good  quali- 
ties of  gold.  The  chemical  equivalent  of 
gold  is  probably  about  200,  and  that  of 
the  protoxide  208,  and  of  the  protochlo- 
ride  236.  The  peroxide  is  a  compound  of 
one  proportional  of  gold  and  three  of  oxy- 
gen, and  the  perchloride  contains  three 
proportionals  of  chlorine.  When  ether  is 
agitated  with  solution  of  chloride  of  gold, 
it  takes  up  the  metal,  and  forms  a  yellow 
ethereal  solution  of  gold;  when  polished 
steel  instruments  are  dipped  into  this  so- 
lution, and  immediately  washed  in  water, 
and  wiped  with  a  piece  of  soft  leather, 
they  become  beautifully  gilt  with  a  very 
thin  film  of  gold.    See  Gilding. 

For  the  separation  of  gold  in  a  spongy 
form,  Dr.  C.  Jackson,  of  Boston,  adopts 
an  economical  plan.  After  separating 
the  gold  and  silver  by  aqua  regia,  the  so- 
lution containing  gold  and  copper  is  eva- 
porated to  a  small  bulk,  and  the  excess 
of  nitric  acid  driven  of.  A  little  oxalic 
acid  is  then  added,  and  a  solution  of  car- 


bonate of  potass  sufficient  to  take  up 
nearly  all  the  gold  as  aurite  of  potass,  is 
gradually  added.  Then  an  excess  of  ox- 
alic acid  is  added,  and  the  whole  boiled. 
The  gold  is  immediately  precipitated  in 
the  form  of  sponge :  this  is  a  suitable 
form  for  the  jeweller  and  dentist. 

Gold,  Artificial:  The  following  ia 
Hemsdorf's  proportions  for  imitation 
gold,  which  not  only  resembles  gold  in 
color,  but  also  in  specific  gravity  and 
ductility ;  it  consists  of  16  parts  of  plati- 
tinum,  7  parts  of  copper  and  1  of  zinc, 
put  in  a  crucible,  covered  with  charcoal 
powder,  and  melted  into  a  mass. 

Gold,  Amalgam  :  Place  a  gold  leaf  in 
the  palm  of  the  hand,  and  pour  upon  it 
a  globule  of  mercury.  The  latter  will  be 
seen  to  absorb,  or  combine  with  the  gold ; 
forming  a  more  or  less  fluid  and  yellow 
amalgam,  according  to  the  proportion  oi 
the  two  metals.  This  amalgam  is  used 
in  water  gilding.  The  affinity  of  mercu- 
ry for  gold  and  silver  is  so  strong,  that 
those  who  are  foolish  enough  to  clean 
their  watch  cases  with  mercury,  or  one 
of  its  salts,  will  find  them  irretrievably 
spoiled  ;  the  same  holds  good  with  plated 
articles  cleaned  by  a  vile  composition, 
sold  about  the  streets  for  this  purpose, 
made  of  the  nitrate  of  mercury,  ground 
up  with  whitening. 

Water  gilders  adopt  the  following  plan 
to  make  amalgam  :  They  put  2  drachms 
of  mercury  into  a  crucible,  and  heat  it 
until  vapor  is  seen  to  issue  from  it ;  now 
throw  into  the  crucible  1  drachm  of  gold 
or  silver,  and  stir  them  with  an  iron  rod. 
When  the  gold  or  silver  is  found  to  be 
fused,  or  incorporated  with  the  mercury, 
the  amalgam  is  poured  into  cold  water ; 
when  cold,  pour  off  the  water,  and  col- 
lect the  amalgnm,  which  will  be  of  about 
the  consistence  of  soft  butter.  This  af- 
ter having  been  bruised  in  a  mortar,  or 
shaken  in  a  strong  phial,  with  repeated 
portions  of  salt  and  water,  till  the  water 
ceases  to  bo  fouled  by  it,  is  fit  for  use, 
and  may  be  kept  for  any  length  of  time 
without  injury  in  a  stopped  phial.  It  is 
essential  in  this  manufacture,  that  the 
mercury  should  be  extremely  pure,  as  the 
least  admixture  of  lead,  tin,  or  metal  would 
materially  injure  the  gilding  for  which  it 
is  used. 

GOLD-BEATING.  The  malleability 
and  extreme  divisibility  of  gold  are  the 
foundation  of  the  art  oi  gold-beating.  In 
consequence  of  the  wonderful  extension 
which  the  gold-beater  is  enabled  to  give 
to  this  precious  metal,  it  is  employed  for 
ornamental  purposes  to  an  extent  which, 


222 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gol 


from  its  comparative  scarcity,  would  oth- 
erwise be  impossible.  Thus,  it  is  esti- 
mated that  an  equestrian  statue,  of  the 
natural  size,  may  be  gilded  with  a  piece 
of  gold  not  exceeding  in  value  $3.  The 
gilding  of  the  dome  of  the  Hotel  des  Inva- 
lids at  Paris  cost  but  £3500.  And  in  In- 
dia, where  it  is  common  to  gild  towers, 
bridges,  gate3,  and  colossal  idols,  it  is 
known  to  be  attended  with  still  less  ex- 
pense. In  gold-beatvng.  the  gold  used  is 
as  pure  as  possible,  antl  the  operation  is 
commenced  with  masses  weighing  about 
two  oz.  These  are  beaten  into  plates  six 
or  eight  inches  long,  by  three  quarters  of 
an  inch  wide.  They  are  then  passed  be- 
tween steel  rollers," till  they  become  as 
thin  as  paper.  Each  one  of  these  is  now 
cut  into  150  pieces,  and  forged  on  an  an- 
vil till  it  is  about  an  inch  square,  after 
which  they  are  well  annealed.  Each  of 
the  squares  in  this  state  weighs  6'4  grs., 
and  in  thickness  is  equal  to  l-766th  of  an 
inch.  The  150  plates  of  gold,  thus  pro- 
duced from  one  mass,  are  interlaid  with 
pieces  of  very  fine  vellum,  about  four 
inches  square,  and  about  20  vellum 
leaves  are  placed  on  the  outside;  the 
whole  is  then  put  into  a  case  of  parch- 
ment, over  which  is  drawn  another  simi- 
lar case,  so  that  the  packet  is  kept  close 
and  tight  on  all  sides.  It  is  now  laid  on 
a  smooth  block  of  marble,  and  the  work- 
man begins  the  beating  with  a  round- 
faced  hammer,  of  16  lbs ;  the  packet  is 
turned,  occasionally,  upside  down,  and 
beaten  with  strong  strokes,  till  the  gold 
is  extended  nearly  to  an  equality  with  the 
vellum  leaves.  The  packet  is  then  taken 
to  pieces,  and  each  leaf  of  gold  is  divided 
into  four  with  a  steel  knife.  The  600 
pieces,  thus  produced,  are  interlaid  with 
pieces  of  animal  membrane,  from  the  in- 
testines of  the  ox^of  the  same  dimension, 
and  in  the  same  manner  as  the  vellum. 
The  beating  is  continued,  but  with  a 
lighter  hammer,  about  12  lbs.,  till  the 
gold  is  brought  to  the  same  dimensions 
as  the  interposed  membrane.  It  is  now 
again  divided  into  four,  by  means  of  a 
piece  of  cane,  cut  to  an  edge.  The  2400 
leaves  hence  resulting  are  parted  into 
three  packets,  with  interposed  membrane 
as  before,  and  beaten  with  the  finishing, 
or  gold  hammer.  The  packets  are  now 
taken  to  pieces,  and  the  gold  leaves,  by 
means  of  a  cane  instrument  and  the 
breath,  are  laid  flat  on  a  cushion  of  lea- 
ther, and  cut,  one  by  one,  to  an  even 
square,  by  a  cane  frame ;  they  are  lastly 
la> }  in  books  of  25  leaves  each,  the  paper 
o/   arhich  is   previously  smoothed,  and 


rubbed  with  red  bole,  to  prevent  them 
j  from  adhering. 

Gold  Wibe  is,  in  fact,  only  silver  wire 
gilt,  and  is  prepared  in  the  following 
manner :  A  solid  cylinder  of  fine  silver, 
weighing  about  20  lbs.,  is  covered  with 
thick  leaves  of  gold,  which  are  made  to 
adhere  inseparably  to  it,  by  means  of  the 
burnisher:  successive  laminae  are  thus 
applied,  till  the  quantity  of  gold  amounts 
to  100^  grs.  for  every  lb.  troy  of  silver. 
This  gilt  silver  rod  is  then  drawn  succes- 
sively through  holes  made  in  a  strong 
steel  plate,  till  it  is  reduced  to  the  size  of 
a  thick  quill,  care  being  taken  to  anneal 
it  accurately  after  each  operation.  The 
succeeding  process  is  similar  to  the  for- 
mer, except  that  a  mixed  metal,  somewhat 
softer  than  steel,  is  employed  for  the 
drawing-plates,  in  order  to  "prevent  the 
gilding  from  being  stripped  off;  and  no 
further  annealing  is  requisite  after,  if  it 
is  brought  to  be  as  slender  as  a  crow- 
quill.  When  the  wire  is  spun  as  thin  as 
is  necessary,  it  is  wound  on  a  hollow  cop- 
per bobbin,  and  carefully  annealed  by  a 
very  gentle  heat;  finally,  it  is  passed 
through  a  flatting  mill,  and  the  process  is 
complete. 

Gold  Thread. — The  gold  thread  com- 
monly used  in  embroidery  consists  of 
threads  of  yellow  silk,  covered  by  flat- 
tened gilt  wire,  closely  wound  upon  them 
by  machinery. 

Crystallization  of  Gold.  A  small 
glass-stoppered  vial,  containing  a  solu- 
tion of  gold  in  a  mixture  of  nitric  and 
muriatic  acids,  had  stood  neglected  for  a 
considerable  time  (perhaps  four  or  five 
years)  in  a  cupboard.  Upon  accidentally 
examining  it,  it  was  found  a  portion  of  the 
acid  had  escaped,  and  the  gold  crystalliz- 
ed. This  effect  had  probably  been  pro- 
moted by  a  flaw  in  the  vial,  which  extend- 
ed through  the  neck,  and  a  little  way 
down  its  length.  The  stopper  in  conse- 
quence must  have  been  slightly  loosened, 
and  thus  allowed  more  space  for  the  for- 
mation of  a  thin  dendritic  crystallization 
of  the  gold.  This  was  further  continued 
down  the -inner  surface  of  the  vial,  and 
was  there  sufficiently  thick  to  admit  the 
impression  of  minute,  but  distinct  crys- 
tallization facets.  A  small  crystallized 
lump  of  gold  lay  at  the  bottom  of  the  vial ; 
but  supposed  to  have  been  originally  at- 
tached to  the  rest,  and  merely  by  its 
weight,  as  has  since  observed  to  be  the 
case  in  another  portion.  Around  the 
stopper,  and  along  the  flaw,  there  was  a 
saline  concretion,  which  tasted  like  sal- 
ammoniac,  and  as  ammonia  was  kept  in 


GOV] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


the  same  cupboard,  it  had  probably  uni- 
ted with  the  muriatic  acid  as  it  exuded. 
On  examining  some  other  metallic  so- 
lutions, it  was  found  that  a  similar 
separation  of  the  metal  had  taken  place 
in  a  vial  containing  a  solution  of  pla- 
tina,  and  in  another,  containing  a  so- 
lution of  palladium.  In  both  these  cases, 
a  thin,  interrupted,  and  dentritic  lamina 
of  metal  might  be  seen  between  the 
stopper  and  the  neck  ;  but  the  crys- 
tallization had  proceeded  no  further.  On 
unstopping  the  vial  containing  the  pla- 
tina,  the  lamina  (as  might  have  been 
expected)  immediately  disappeared  in 
the  form  of  a  slight  muddy  film. 
These  facts,  if  multiplied,  may,  per- 
haps, serve  to  throw  some  light  upon  the 
mode  in  which  the  dentritic  laminae  of 
native  gold,  silver,  &c,  are  formed  in 
rocks. 

Gold  (Chloride  of).  Great  difficulty 
has  hitherto  occurred  in  preparing  the 
chloride  of  gold,  of  the  yellow  and  red 
colors,  perfectly  soluble  in  water,  and 
without  suffering  reduction.  The  follow- 
ing processes  are  recommended  for  this 
purpose : — 

1st.  In  order  to  prepare  the  yellow  salt 
of  gold,  take  aqua  regia  prepared  with 
three  parts  of  hydro-chloric  acid,  one  part 
of  nitric  acid,  and  one  of  distilled  water. 
Then  put  one  part  of  pure  gold  into  a 
porcelain  capsule  with  a  plate  of  glass, 
and  heat  it  in  a  salt  water  bath,  the  heat 
being  eontinued  till  red  vapors  cease ; 
the  cover  is  then  to  be  removed,  and  if 
the  gold  is  not  entirely  dissolved,  some 
aqua  regia  is  to  be  added  to  it,  the  cap- 
sule being  again  covered,  the  heat  is  to 
be  continued  till  vapor  ceases  to  appear ; 
the  glass  plate  must  then  be  removed  ana 
replaced  by  folds  of  blotting  paper,  the 
heat  being  continued  in  the  bath,  until  a 
glass  rod,  upon  being  immersed  in  the 
capsule,  becomes  covered  with  yellow 
solid  chloride  of  gold. 

The  capsule  is  then  to  be  removed  from 
the  salt  water  bath  and  the  chloride  of 
gold  soon  crystallizes  in  small  prismatic 
crystals,  of  a  fine  yellow  color,  with  an 
orange  tint.  The  chloride  thus  obtained 
is  perfectly  soluble  in  water  without  re- 
duction ;  it  is  successfully  employed  in 
Daguerreotype  and  other  operations. 

The  red  chloride  of  gold  (ter-chloride) 
is  prepared  in  the  same  manner,  except 
that  the  aqua  regia  employed  is  prepared 
with  two  parts  of  hydro-chloric,  and  one 
part  of  nitric  acid.  The  operation  is 
commenced  by  acting  upon  gold  with 
excess  of  aqua  regia  on  a  sand  bath,  the 


salt  water  bath  not  being  used  until  the 
gold  is  entirely  dissolved ;  the  remainder 
of  the  operation  is  conducted  in  the  same 
manner  as  that  for  the  vellow  chloride. 

GOVEENOK.  A  contrivance  for  re- 
gulating the  speed  of  machinery,  which 
has  long  been  in  use  in  mill- work,  but 
has  of  late  years  attracted  more  attention 
by  its  adaptation  to  the  steam-engine.  It 
consists  of  two  heavy  balls  B  B,  attached 
to  the  extremi- 
ties of  two  rods 
B  F,  B  F,  which 
play  upon  a  joint 
at  E,  passing 
through  a  mor- 
tise in  the  verti- 
cal shaft  D  D. 
These  are  united  by  joints  at  F  to  the 
short  rods  F  II,  which  again  are  connect- 
ed by  joints  at  II  to  a  ring,  which  slides 
on  the  shaft  DD.  A  horizontal  wheel, 
W,  is  attached  to  ~D  D,  having  a  groove 
to  receive  a  rope  or  strap  on  its  rim,  by 
means  of  which  the  motion  is  communi 
cated  to  D  I)  from  a  corresponding  wheel 
on  some  shaft  of  the  machinery  to  be  re- 
gulated. It  is  evident,  from  the  disposi- 
tion of  the  rods,  that  if  the  balls  B  B  are 
by  any  means  raised  or  drawn  asunder, 
the  extremities  F  F  of  the  rods  turning 
on  the  pivot  E  will  also  be  separated,  and 
their  distance  from  the  axes  increased. 
This  will  draw  the  rods  F  II  in  the  same 
direction,  and  cause  the  ring  or  collar  II 
to  descend.  This  ring  is  connected  with 
the  end  I  of  a  lever,  whose  fulcrum  is  at 
G,  and  whose  other  extremity  K  is  con- 
nected by  some  means  with  the  part  of 
the  machine  which  supplies  the  power. 
Suppose  now  the  velocity  from  any  cause 
to  undergo  a  sudden  increase  ;  by  reason 
of  the  increased  centrifugal  force  arising 
from  the  whirling  motion,  the  balls  B  B 
will  recede  from  the  shaft  D  D,  and  raise 
the  extremity  K  of  the  lever.  On  the 
other  hand,  if  the  velocity  is  diminished, 
the  centrifugal  force  of  the  balls  will  be 
diminished,  and  they  will  fall  by  their 
own  weight  nearer  the  axes,  and  cause 
the  end  K  of  the  lever  to  descend.  When 
the  governor  is  applied  to  a  steam-en- 
gine, the  rod  K  1  communicates  with  a 
flat  circular  valve  V,  placed  in  the  princi- 
pal steam-pipe,  and  so  arranged  that  when 
K  is  elevated  as  far  as  the  divergence  of 
the  balls  will  allow,  the  opening  of  the 
pipe  will  be  closed  by  the  valve  V,  and 
the  passage  of  steam  entirely  stopped. 
On  the  other  hand,  when  the  balls  sub- 
side to  their  lowest  position,  the  valve 
will  be  entirely  open.    Thus,  when  the 


224 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[< 


Velocity  is  increased,  the  supply  of  steam 
is  checked  ;  and  when  it  is  diminished, 
the  supply  of  steam  is  immediately  in- 
creased; by  which  means  a  uniform  proper 
velocity  of  the  machinery  is  maintained. 
.  When  the  governor  is  applied  to  a 
water  wheel,  the  lever  is  made  to  act  on 
the  shuttle  through  which  the  water 
flows,  and  thereby  controls  its  quantity. 
"When  applied  to  ft  windmill,  it  regulates 
the  sailcloth  so  as  to  diminish  the  efficacy 
of  the  power  upon  the  arms  as  the  force 
of  the  wind  increases,  or  vice  versa. 

GRAFTING.  The  operation  of  affix- 
ing one  portion  of  a  plant  to  another,  in 
such  a  manner  as  that  vital  union  may 
take  place  between  them.  A  graft  con- 
sists of  two  parts ;  the  stock  or  stem, 
which  is  a  rooted  plant,  fixed  in  the 
ground,  and  the  scion,  a  detached  por- 
tion of  another  plant,  to  be  affixed  to  it. 
The  operation  ot  grafting  can  only  be  per- 
formed within  certain  limits. 

In  general,  all  the  species  of  one  genus 
may  be  grafted  on^one  another  recipro- 
cally ;  but  this  is  not  universally  the  case, 
because  the  apple  cannot  be  grafted  on 
the  pear,  at  least  not  for  any  useful  pur- 
pose. In  general,  it  may  be  presumed 
that  all  the  species  of  a  natural  order,  or 
at  least  of  a  tribe,  may  be  grafted  on  one 
another ;  but  this  does  not  "hold  good  uni- 
versally. The  reverse  of  this  doctrine, 
however,  that  the  species  belonging  to 
different  natural  orders  cannot  be  grafted 
on  one  another  holds  almost  universally 
true ;  and  therefore  a  safe  practical  con- 
clusion is,  that  in  choosing  a  stock,  the 
nearer  in  affinity  the  species  to  which  that 
stock  belongs  is  to  the  scion,  the  more 
certain  will  be  the  success. 

Grafting  is  one  of  the  most  important 
operations  in  horticulture,  as  affording 
the  most  eligible  means  of  multiplying 
and  perpetuating  all  our  best  varieties  of 
fruit-trees,  and  many  kinds  of  trees  and 
shrubs  not  so  conveniently  propagated  by 
other  means.  Varieties  of  fruits  are  ori- 
ginally procured  by  selection  from  plants 
raised  from  seed,  but  they  can  only  be 
perpetuated  by  some  mode  which  con- 
tinues the  individual ;  and  though  this 
may  be  done  by  cuttings  and  layers,  yet 
by  far  the  most  eligible  mode  is  by  graft- 
ing, as  it  produces  stronger  plants  in  a 
shorter  time  than  any  other  methods. 

Grafting  is  performed  in  a  great  many 
different  ways,  but  the  most  eligible 
for  ordinary"  purposes  is  what  is  com- 
monly called  spliced  grafting  or  whip 
grafting.  In  executing  this  mode,  both 
the    scion    and   the    stock    are    pared 


down  in  a  slanting  direction ;  afterward 
applied  together,  and  made  fast  with 
strands  of  bast  matting,  in  the  same 
manner  as  two  pieces  of  rod  are  spliced 
together  to  form  a  whip  handle.  To  in- 
sure success,  it  is  essentially  necessary 
that  the  alburnum  or  inner  bark  of  the 
scion  should  coincide  accurately  with  the 
inner  bark  of  the  stock,  because  the  vital 
union  is  effected  by  the  sap  of  the  stock 
rising  up  through"  the  soft  wood  of  the 
scion.  After  the  scion  is  tied  to  the 
stock,  the  graft  is  said  to  be  made ;  and 
it  only  remains  to  cover  the  part  tied 
with  a  mass  of  tempered  clay,  or  any 
convenient  composition  that  will  exclude 
the  air.  The  season  for  performing  the 
operation  is,  for  all  deciduous  trees  and 
shrubs,  the  spring,  immediately  before 
the  movement  of  the  sap.  The  spring 
is  also  the  most  favorable  season  for  ever- 
greens ;  but  the  sap  in  this  class  of  plants 
being  more  in  motion  during  winter  than 
that  of  deciduous  plants,  grafting,  if 
thought  necessary,  might  be"  performed 
at  that  season. 

Grafting  by  approach,  or  inarching,  is 
a  mode  of  grafting,  in  which,  to  make 
sure  of  success,  the  scion  is  not  separated 
from  the  parent  plant  till  it  has  become 
united  with  the  stock.  For  this  pur- 
pose, the  stock  and  the  plant  containing 
the  scion  must  be  growing  close  together ; 
and  the  scion  being  drawn  to  one  side, 
and  made  to  approach  the  stock,  is  spliced 
to  it  by  cutting  off  a  portion  of  its  bark 
and  wood,  and  a  similar  portion  of  the 
bark  and  wood  of  the  stock,  applying  the 
one  to  the  other  so  that  their  alburnums 
may  join,  and  then  making  both  fast  by 
matting,  and  excluding  the  air  by  clay, 
grafting  wax,  or  moss.  When  the  scion 
has  effected  a  vital  union  with  the  stock, 
its  lower  extremity  is  cut  through,  so  as 
to  separate  it  from  the  parent  plant,  and 
it  now  becomes  an  independent  graft. 
In  this  way  trees  of  difficult  propagation 
may  be  propagated  with  certainty  ;  while 
if  any  of  the  other  modes  of  propagation, 
whether  by  cuttings  or  grafting,  were 
adopted,  a  proportion  of  the  cuttings  or 
scions  would ,  in  all  probability,  be  lost. 

Grafting  herbaceous  plants  differs  in  no- 
thing from  grafting  such  as  are  of  a 
woody  nature,  excepting  that  the  opera- 
tion is  performed  when  both  stock  and 
scion  are  in  a  state  of  vigorous  growth. 
Grafting  herbaceous  plants  is  but  little 
practised  in  England,  and  on  the  Conti- 
nent chiefly  as  a  matter  of  amusement. 
The  only  useful  purpose  to  which  it  lias 
hitherto  been  applied,  is  that  of  grafting 


0 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


225 


the  finer  kinds  of  dahlias  on  tubers  of  the 
more  common  and  vigorous  growing  sorts. 
In  the  Paris  gardens  the  tomato  is  some- 
times grafted  on  the  potato,  the  cauli- 
flower on  the  borecole,  and  one  gourd  on 
another,  as  matter  of  curiosity. 

Grafting  the  herbaceous  shoots  of  woody 
plants — the  greffe  herbace  of  the  French 
— is  scarcely  known  among  English  gar- 
deners ;  but  it  has  been  extensively  em- 
ployed by  French  nurserymen,  and  even 
in  some  of  the  royal  forests  of  France. 
The  scions  are  formed  of  the  points  of 
growing  shoots ;  and  the  stocks  are  also 
the  points  of  growing  shoots  cut  or 
broken  over  an  inch  or  two  below  the 
point,  where  the  shoot  is  as  brittle  as  as- 
paragus. The  operation  is  performed  in 
the  cleft,  manner  :  that  is,  by  cutting  the 
lower  end  of  the  scion  in  the  form  of  a 
wedge,  and  inserting  it  in  a  cleft  or  slit 
made  down  the  middle  of  the  stock.  The 
finer  kinds  of  azalias,  pines,  and  firs  are 
propagated  in  this  way  in  the  French 
nurseries,  and  thousands  of  Pinus  lari- 
cio  have  been  so  grafted  on  Pinus  sylves- 
tres  in  the  forest  of  Fontainebleau.  At 
Hopetouii  House,  near  Edinburgh,  this 
mode  of  grafting  has  been  successfully 
practised  with  Abies  Smithiana,  the  stock 
being  the  common  spruce  fir. 

GRANITE  is  considered  as  the  foun- 
dation rock  of  the  globe,  or  that  upon 
which  all  secondary  rocks  repose.  From 
its  great  relative  depth,  it  is  not  often 
met  with,  except  in  Alpine  situations, 
where  it  presents  the  appearance  of  hav- 
ing broken  through  the  more  superficial 
strata  of  the  earth,  the  beds  of  other 
rocks  in  the  vicinity  rising  towards  it  at 
increasing  angles  of  elevation  as  they  ap- 
proach it.  It  is  composed  of  three  mi- 
nerals, viz.,  quartz,  feldspar,  and  mica, 
which  are  more  or  less  perfectly  crystal- 
lized and  closely  united  together. 

The  three  constituents  of  granite  are 
as  under,  taking  their  mean  : 

Feldspar.  Quartz.  Mica. 

Silica 64  96  47 

Alumina 19  2  22 

Lime 2  2 

Potash 13  o  14-5 

Iron,  (oxide)  1  0  15 

Mang.  (do.) .  0  0                1'75 

Granite  has  been  divided  into  several 
sub-species,  or  varieties  ;  of  these,  the 
following  are  the  most  important :  — 
Common  granite,  in  which  the  three 
ordinary  constituents  above-mentioned 
occur  in  nearly  equal  proportions  ;  the 
feldspar  may  be  white,  red.  or  gray. 
Porphyritic  granite,  in  which  large  crys- 
10* 


VU1IOWUO         K7L  X^XVX0^7t*l  «1  WAV 

penetrated    perpendicularly 
imperfect  crystals  of  quartz,  \ 


tals  of  feldspar  are  disseminated  through 
a  common  granite,  whose  ingredients 
are  fine  grained.  Graphic  granite,  which 
consists  of  feldspar  in  broad  laminae, 
with  long 
whose  trans- 
verse angular  sections  bear  some  resem- 
blance to  certain  letters,  especially  to 
those  of  Oriental  languages.  Sienite  or 
sienitic  granite,  in  which  hornblende, 
either  wholly  or  in  part,  supplies  the 
place  of  mica.  Talcky  or  chloruic  granite 
(the  protogine  of  the  French),  in  which 
talc  or  chlorite  takes  the  place  of  the 
mica.  FeHspathic  granite,  in  which  feld- 
spar is  the  principal  ingredient. 

The  aspect  of  granitic  mountains  is 
extremely  diverse,  depending,  in  part, 
upon  the  nature  of  its  stratification,  and 
the  degree  of  disintegration  it  has  under- 
gone. Where  the  beds  are  nearly  hori- 
zontal, or  where  the  granite,  from  the 
preponderance  of  feldspar,  is  soft  and 
disintegrating,  the  summits  are  rounded 
and  heavy.  Where  hard  and  soft  granite 
are  intermixed  in  the  same  mountain, 
the  softer  granite  is  disintegrated,  and 
falls  away,  leaving  the  harder  blocks  and 
masses  piled  in  confusion  upon  each 
other,  like  an  immense  mass  of  ruins. 
Where  it  is  hard,  and  the  beds  are  nearly 
vertical,  it  forms  lofty  pyramidal  peaks 
or  aiguilles,  like  the  Aiguille  de  Due  and 
others,  in  the  neighborhood  of  Mont 
Blanc. 

Granite  forms  some  of  the  most  lofty 
of  the  mountain-chains  of  the  eastern 
continent.  In  Europe,  the  central  part 
of  the  principal  mountain-ranges  is  of 
this  rock — as  in  Scandinavia,  the  Alps, 
the  Pyrenees,  and  the  Carpathian  moun- 
tains. In  Asia,  granite  forms  a  consi- 
derable part  of  the  Uralian  and  Altaic 
ranges  of  mountains  ;  and  it  appears, 
also,  to  compose  the  principal  mountains 
that  have  oeen  examined  in  Africa ; 
whereas,  in  the  western  hemisphere,  it 
has  never  been  observed  rising  to  such 
great  elevations,  or  composing  such  ex- 
tensive chains.  It  is,  nevertheless,  very 
abundantly  distributed  over  the  northern 

Earts  of  the  American  continent,  as  in 
.abrador,  the  Canadas,  and  the  t  New 
England  States.  In  New  Hampshire,  it 
is  the  predominating  rock  of  the  White 
Mountains,  in  which  it  attains  the  eleva- 
tion of  more  than  6000  feet.  In  the 
Andes,  it  has  been  observed  at  the 
height  of  11,000,  but  is  here  generally 
covered  by  an  immense  mass  of  matter, 
ejected  by  ancient  and  recent  eruptions. 
Granite  very  frequently  forms  veins 


226 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gra 


shooting  up  into  the  superincumbent 
rocks,  which  seems  to  indicate  that  it 
has  existed  below  in  a  state  of  fusion, 
the  heat  of  which  has  softened  and 
parted  the  tipper  rocks,  and  forced  up 
the  granite,  in  a  melted  state,  into  these 
fissures. 

Granite  abounds  in  crystallized  earthy- 
minerals  ;  and  these  occur,  for  the  most 
part,  in  those  masses  of  it  existing  in 
veins.  Of  these  minerals,  beryl,  garnet., 
and  tourmaline,  are  the  most  abundant. 
It  is  not*rich  in  metallic  ores,  though  it 
contains  the  principal  mines  of  tin,  as 
well  as  small  quantities  of  copper,  iron, 
tungsten,  bismuth,  silver,  columbiurn, 
and  molybdenum. 

Granite  supplies  durable  materials  for 
architecture  and  for  decoration.  It  va- 
ries much  in  hardness,  as  well  as  in  co- 
lor ;  accordingly,  there  is  room  for  much 
care  and  taste  in  its  selection. 

GRANULATION  ;  the  method  of  di- 
viding metallic  substances  into  grains  or 
small  particles.  This  is  done  either  by 
pouring  the  melted  metal  into  water,  or 
by  agitating  it  in  a  box  until  the  moment 
of  coagulation,  at  which  instant  it  be- 
comes converted  into  a  powder. 

GRAPES.  The  method  of  training 
vines  at  Fontainebleau,  where  the  famous 

f rapes  are  produced  that  supply  the 
'ans  markets,  consists  in  allowing  the 
plants  very  little  room  to  grow  either 
with  their  branches  or  their  roots,  and 
in  keeping  the  latter  very  near  the  sur- 
face of  the  ground ;  each  vine  is  only 
allowed  to  occupy  a  space  of  about  six 
feet,  so  that  the  walls  are  supplied  by  a 
multitude  of  plants. 

The  error  in  growing  grapes  in  Britain 
consists  in  training  them  into  elevations. 
They  ripen  best  when  trained  near  the 

ground,  in  open  air.  The  heat  of  hot- 
ouses  is  an  exception.  Vineyards,  in 
France,  resemble  plantations  of  goose- 
berry-bushes, with  the  bunches  close  to 
the  soil,  the  heat  of  which  ripens  them. 
Grape  Wine.  Take  water  4J  galls., 
grapes  5  galls.,  crushed  and  soaked  in 
the  water  7  days,  sugar  17£  lbs.  The 
cask  in  which  it  was  made  held  exactly 
6f  galls.,  and  produced  34  bottles  of  wine 
clear.  A  bottle  kept  10  years  proved 
very  good. 

To  preserve  Grapes.  Take  a  well-bound 
cask,  from  which  the  head  is  to  be  re- 
moved, and  place  at  the  bottom  a  good 
layer  of  bran.  On  this  place  a  layer  of 
grapes,  then  bran  and  grapes  alternately 
until  the  cask  is  full.  Put  on  the  head, 
which  is  to  be  cemented,  and  the  grapes 


>will  keep  for  a  year.  When  used,  in 
order  to  restore  their  freshness,  fresh 
cut  the  stalk  of  each  bunch,  and  place  it 
in  wine,  as  flowers  are  placed  in  water. 

GRAPE-SHOT.  In  artillery,  a  quan- 
tity of  small  shot  put  into  a  canvas  bag, 
and  corded  together  in  the  form  of  a 
cylinder,  the  diameter  of  which  is  adapt- 
ed to  the  piece  of  ordnance  from  which 
it  is  intended  to  be  discharged.  It  is 
now  superseded  by  canister-shot. 

GRAPHOMETER.  A  mathematical  in- 
strument used  in  land  surveying ;  other- 
wise called  a  semicircle. 

GRAPHITE.  The  substance  impro- 
perly called  black  lead,  of  which  pencils 
are  made.  It  is  a  peculiar  form  of  mi- 
neral carbon  with  a  trace  of  iron.  The 
finest  is  found  only  at  Borrodale  in  Cum- 
berland. Coarse  varieties  are  not  un- 
common. It  occurs  very  abundantly 
throughout  the  United  States. 

GRAPNEL.   A  small  anchor  for  a  boat. 

GRAPPLING  IRONS.  Small  grapnels 
with  four  flukes  for  securing  ships  toge- 
ther in  action. 

GRASS,  is  the  union,  in  spring,  of  11 
species  of  natural  grasses  in  one  pasture ; 
in  summer  of  11  other  species,  and  in 
autumn  of  3  others,  florin,  yarrow,  and 
couch.  Certain  weeds  and  flowers,  also, 
mingle  in  small  quantities,  as  butter- 
cups, burnet,  sorrel,  dock,  &c.  Some 
species  prevail  in  particular  soils,  but  the 
most  general  in  all,  is  cocksfoot,  meadow- 
fescue,  crested  dog's-tail,  hand-fescue, 
sweet-scented  vernal,  rye,  (grasses,)  and 
upright  brome.  The  meadow  fox-tail 
and  oat-grasses  occasionally  abound. 

GRAY  DYE.  The  gray  dyes,  in  their 
numerous  shades,  are  merely  various  tints 
of  black,  in  a  more  or  less  diluted  state, 
from  the  deepest  to  the  lightest  hue. 

The  dyeing  materials  are  essentially 
the  tannic  and  gallic  acid  of  galls  or  other 
astringents,  along  with  the  sulphate  or 
acetate  of  iron,  and  occasionally  wine- 
stone.  Ash-gray  is  given  for  30  pounds 
of  woollen  stuff,  by  one  pound  of  gall- 
nuts,  i  pound  of  wine-stone  (crude  tar- 
tar), ana  2i  pounds  of  suiphate  of  iron. 
The  galls  and  the  wine-stone  being  boiled 
with  from  70  to  80  pounds  of  water,  the 
stuff  is  to  be  turned  through  the  decoc- 
tion at  a  boiling  heat  for  half  an  hour, 
then  taken  out,  when  the  bath  being  re- 
freshed with  cold  water,  the  copperas  is 
to  be  added,  and,  as  soon  as  it  is  dissolved, 
the  stuff  is  to  be  put  in  and  fully  dyed. 

Pearl-gray  is  produced  by  passing  the 
stuff  first  through  a  decoction  of  sumach 
and  logwood  (two  pounds  of  the  former 


oua] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


227 


to  one  of  the  latter),  afterwards  through 
a  dilute  solution  of  sulphate  or  aceiatc  of 
iron  ;  and  finishing  it  in  a  weak  bath  oT 
weld  containing  a  little  alum.  Mouse- 
gray  is  obtained,  when  with  the  same 
proportions  as  for  ash-gray,  a  small  quan- 
tity of  alum  is  introduced. 

For  several  other  shades,  as  tawny- 
gray,  iron-gray,  and  sla^e-gray,  the  stuff 
must  receive  a  previous  blue  ground  by 
dipping  it  in  the  indigo  vat ;  then  it  is 
passed  first  through  a  boiling  bath  of 
sumach  with  galls,  and  lastly  through 
the  same  bath  at  a  lower  temperature 
after  it  has  received  the  proper  quantity 
of  solution  of  iron. 

For  dyeing  silk  gray,  fustet,  logwood, 
sumach,  and  elder-tree  bark,  are  employ- 
ed instead  of  galls.  Archil  and  annotto 
are  frequently  used  to  soften  and  beau- 
tify the  tint. 

GRAVITY.     (See  Specific  Gkavity.) 
GREASE.    Anti-attrition  for  axles  : 
1st.  One  part  of  fine  black  lead,  ground 

gerfectly  smooth,  with  four  parts  lard, 
ome  recipes  add  a  little  campnor. 
2d.  Booth's  Axle  Gkease,  (expired  pa- 
tent.) Dissolve  £  lb.  of  common  soda  in 
1  gallon  of  water;  add  3  lbs.  of  tallow, 
and  6  lbs.  palm  oil  (or  10  lbs.  palm  oil 
only),  heat  them  together  to  200  or  210° 
Fahr. ;  mix  and  keep  the  mixture  con- 
stantly stirred  till  the  composition  is 
cooled  down  to  60  or  70°.  A  thinner 
composition  is  made  with  i  lb.  of  soda,  a 
gallon  of  water,  a  gallon  of  rape  oil,  and 
\  lb.  of  tallow  or  palm  oil. 

GREEN  PAINTS.  Green,  which  is  so 
common  a  color  in  the  vegetable  kingdom, 
is  very  rare  in  the  mineral.  There  is  only 
one  metal,  copper,  which  affords  in  its 
combinations  uiq  various  shades  of  green 
in  general  use.  The  other  metals  capable 
of  producing  this  color  are,  chromium  in 
its  protoxycfe,  nickel  in  its  hydrated  ox- 
yde,  as  well  as  its  salts,  the  seleniate,  ar- 
seniate,  and  sulphate  ;  and  titanium  in  its 
prussiate. 

Green  pigments  are  prepared  also  by 
the  mixture  of  yellows  and  blues  ;  as,  for 
example,  the  green  of  Rinman  and  of 
Gellert,  obtained  by  the  mixture  of  cobalt 
hlue,  and  flowers  of  zinc;  that  of  Earth, 
made  with  yellow  lake,  Prussian  blue, 
and  clay  ;  but  these  paints  seldom  appear 
in  the  market,  because  the  greens  are  ge- 
nerally extemporaneous  preparations  of 
the  artists. 

Mountain  green  consists  of  the  hydrate, 
cxyde,  or  carbonate  of  copper,  either  fac- 
titious, or  as  found  in  nature. 

Bremen  or  Brunswick  green  is  a  mixture 


of  carbonate  of  copper  with  chalk  or  lime, 
and  sometimes  a  little  magnesia  or  am- 
monia. It  is  improved  by  an  admixture 
of  white  lead.  It  may  be  prepared  by 
adding  ammonia  to  a  mixed  solution  of 
sulphate  of  copper  and  alum. 

Frise  green  is  prepared  with  sulphate  of 
copper  and  sal  ammoniac. 

Mittis  green  is  an  arseniate  of  copper  ; 
made  by  mixing  a  solution  of  acetate  or 
sulphate  of  copper  with  arsenite  of  potash. 
It  is  in  fact  Scheel's  green. 

JSap  green  is  the  inspissated  juice  of 
buckthorn  berries.  These  are  allowed  to 
ferment  for  8  days  in  a  tub,  then  put  in  a 
press,  adding  a  little  alum  to  the  juice, 
and  concentrated  by  gentle  evaporation. 
It  is  lastly  put  up  in  pigs'  bladders, 
where  it  becomes  dry  and  hard. 

Schweinfurt  green  ;  see  Schweinfcrt. 

Verona' green  is  merely  a  variety  of  the 
mineral  called  green  earth. 

GREEN  VITRIOL  is  sulphate  of  iron 
in  green  crystals. 

GREEN,  PRUSSIAN,  is  the  sediment 
of  the  two  first  processes  for  making 
Prussian  blue,  before  the  muriatic  acid  is 
added  ;  or  it  may  be  made  by  pouring 
oxymuriatic  acid  upon  fresh  precipitated 
Prussian  blue. 

GREYWACKE,  a  German  word  of 
three  syllables,  which  imports  a  forma- 
tion of  distinct  pieces  of  quartz,  hard 
slate,  and  feldspar,  combined  in  a  bed  of 
clay  slate.  But  when  the  pieces  are  gran- 
ulated in  the  clay  state,  it  is  then  called 
grey  wacko  slate.  It  contains  early  shells 
though  a  transition  rock  ;  also  transition 
limestone  and  trap,  with  many  ores  and 
veins.  Since  its  formation  there  must 
have  been  at  least  12  revolutions  of  the 
perihelion. 

GUANO  or  HUANO.  A  substance 
first  noticed  by  Humboldt  andsentby  him 
from  Peru  to  France,  where  it  was  ex- 
amined by  Vauquelin.  It  is  the  excre- 
ment of  sea-birds  inhabiting  the  coast  of 
South  Seas.  Besides  excrement,  it  is 
made  up  of  the  remains  of  penguins, 
albatrosses,  and  gannetts,  booby  birds  and 
seals.  It  is  found  at  Chincha  and  Payta, 
in  Peru,  and  in  Chili.  It  also  abounds  in 
Ichaboe  and  a  few  smaller  islands  off  the 
West  coast  of  Africa.  Peruvian  guano 
is  found  on  the  islands  of  the  Pacific,  near 
the  coast  of  Peru,  and  some  of  the  head- 
lands on  the  adjacent  shores  between  lat. 
13°  and  21°  South.  It  is  here  deposited 
to  the  depth  of  50  and  60  feet.  Within 
this  district  rain  seldom  falls,  and  there 
is  little  waste  either  of  the  substance  or 
quality  of  these  accumulations  from  the 


228 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[qua 


lapse  of  time  or  the  action  of  elements. 
The  water  fowl,  which  resort  to  this  coast 
and  the  vicinal  island,  subsist  principally 
on  lish,  and  their  faeces  are,  of  course, 
richer  in  nitrogen  than  any  species  of  the 
feathered  tribes,  excepting  such  as  are 
exclusively  carnivorous. 

The  Chmcha  islands,  which  afford  the 
best  Peruvian  guano,  are  three  in  num- 
ber, and  lie  in  one  line  from  north  to 
south,  about  half  a  mile  apart.  Each  is- 
land is  from  five  to  six  miles  in  circum- 
ference, and  consists  of  granite  covered 
with  guano  in  some  places  to  a  height  of 
200  feet,  in  successive  horizontal  strata, 
each  stratum  being  from  3  to  10  inches 
thick,  and  varying  in  color  from  light  to 
dark  brown.  No  earthly  matter  whatever 
is  mixed  with  this  vast  mass  of  excre- 
ment. At  Mr.  Bland's  visit  to  these  is- 
lands in  1842,  he  observed  a  perpendicu- 
lar surface  of  upward  of  100  feet  of  per- 
fectly uniform  aspect  from  top  to  bottom. 
In  some  parts  of  these  islands,  however, 
the  deposit  does  not  exceed  3  or  4  feet  in 
thickness.  In  several  places,  where  the 
surface  of  the  guano  is  100  feet  or  more 
above  the  level  of  the  sea,  it  is  strewed 
here  and  there  with  masses  of  granite, 
like  those  from  the  Alpine  mountains, 
which  are  met  with  on  the  slopes  of  the 
Jura  chain.  These  seem  to  indicate  an 
ancient  formation  for  the  guano,  and  ter- 
raqueous convulsions  since  that  period. 
No  such  granite  masses  are  found  imbed- 
ded within  the  guano,  but  only  skeletons 
of  birds. 

The  good  preservation  of  the  Chincha 
guano  is  to  be  ascribed  to  the  absence  of 
rain  ;  which  rarely,  if  ever,  falls  between 
the  latitude  of  14°  south,  where  these  is- 
lands lie,  about  10  miles  from  the  main 
land,  and  the  latitude  of  Paquica,  on  the 
island  of  Bolivia,  in  21°  S.  L.  By  far  the 
soundest  cargoes  of  guano  which  have 
been  analyzed  have  come  from  Chincha  and 
Bolivia.  Beyond  these  limits  of  latitude, 
where  rain  falls  in  greater  or  less  abun- 
dance, the  guano  is  of  less  value — and 
what  has  been  imported  from  Chili  lias 
been  found  very  far  advanced  in  decay 
— most  of  the  ammonia  and  azotized  ani- 
mal substances  having  been  decomposed 
by  moisture,  and  dissipated  in  the  air  (by 
the  eremacausis  of  Licbig),  leaving  phos- 
phate of  lime  largely  to  predominate  along 
with  effete  organic  matter.  The  range  of 
the  American  coast  from  which  the  giiano 
is  taken  must  therefore  be  well  consider- 
ed ;  and  should  not  extend  much  beyond 
the  Chincha  islands  as  the  northern  limit, 
and  Paquica,  in  Bolivia,  as  the  southern. 


Peruvian  guano  is  of  a  light  brown  co- 
lor, resembling  yellow  loam,  and  is  the 
best  guano  yet  discovered,  or  than  any 
other  manure  yet  known  ;  besides  nitro- 
gen, which  it  contains  so  abundantly,  it 
contains  a  large  amount  of  phosphoric 
acid  united  with  lime  and  magnesia,  and 
as  both  of  these  substances  are  so  neces- 
sary to  the  cultivated  crops,  it  is  the  rea- 
son why  this  substance  is  the  manure. 
i  The  following  remarks  of  Dr.  Ure  ex- 
plain this  point  more  fully : — 

The  admirable  researches  of  Professor 
Liebig  have  demonstrated  that  Azote, 
the  indispensable  element  of  the  nourish- 
ment of  plants,  and  especially  of  wheat 
|  and  others  abounding  in  gluten  (an  azo- 
tized product),  must  be  presented  to  them 
:  in  the  state  of  ammonia,  yet  not  altoge- 
ther ammonia  in  the  pure  or  saline  form, 
i  for,  as  such,  it  is  too  readily  evaporated 
|  or  washed  away ;  but  in  the  dormant,  or 
|  as  one  may  say,  in  the  potential  condition 
\  in    contradistinction    from    the    actual. 
;  Genuine  Peruvian  and  Bolivian  guanos, 
|  like  those  which  have  been  minutely  ana- 
j  lyzed,  surpass  very  far  all  other  species  of 
manure,  whether  natural  or  artificial,  in 
:  the  quantity  of  potential  ammonia,   and, 
;  therefore,  in  the  permanency  of  their  ac- 
:  tion  upon  the  roots  of  plants,  while,  in 
:  consequence  of  the  ample  store  of  actual 
'  ammonia  which  they  contain  ready  form- 
ed, they  are  qualified  to  give  immediate 
vigor  to  vegetation.    Urate  of  ammonia 
constitutes  a  considerable  portion  of  the 
!  azotized  organic  matter  in  well-preserved 
1  guano;   it  is  nearly  insoluble  in  water, 
not  at  all  volatile,  and  is  capable  of  yield- 
ing to  the  soil,  by  its  slow  decomposition, 
nearly  one-third  of  its  weight  of  ammonia. 
No  other  manure  can  rival  this  animal  sa- 
line compound.     One  of  the  said  samples 
of  guano  afforded  me  no  less  than  17  per 
cent,  of  potential  ammonia,  besides  4i 
per  cent,  of  the  actual  or  ready  formed  ; 
others  from  7  to  8  per  cent,  of  ammonia 
in    each    of    these    states    respectively. 
These  guanos  which  were  examined  are 
the  mere  excrement  of  birds,   and  are 
quite  free  from  the  sand,  earth,  clay,  and 
common  salt,  reported  in  the  analyses  of 
some  guanos,  and  one  of  which  (sand)  to 
the  amount  of  30  per  cent,  has  been  found 
in  a  sample  of  guano  from  Chile. 

The  Peruvian  guano,  moreover,  con- 
tains from  10  to  25  per  cent,  of  phosphate 
of  lime,  the  same  substance  as  bone-earth, 
but  elaborated  by  the  birds  into  a  pulpy 
consistence,  which,  while  it  continues  in- 
soluble in  water,  has  been  thereby  ren- 
i  dered  more  readily  absorbable  and  diges- 


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CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


229 


tible  (so  to  speak)  by  the  roots  of  plants. 
There  is  therefore  no  doubt,  that  by  the 
judicious  application  of  these  genuine  gu- 
anos, mixed  with  twice  or  thrice  their 
weight  of  a  marly  or  calcareous  soil,  to 
convert  their  phosphate  of  ammonia  into 
phosphate  of  lime  and  carbonate  of  am- 
monia, as  also  to  dilute  all  their  ammoni- 
acal  compounds — such  crops  will  be  pro- 
duced, even  on  sterile  lands,  as  the  far- 
mer has  never  raised  upon  the  most  im- 
proved soil  by  the  best  ordinary  manure. 
To  the  West  India  planter,  guano  will 
prove  the  greatest  boon,  since  it  conden- 
ses in  a  portable  and  inoffensive  shape 
the  means  of  restoring  fertility  to  his  ex- 
hausted cane-fields,  a  benefit  it  has  long 
conferred  on  the  poorest  districts  of  Peru. 
Messrs.  A.  Gibbs,  of  London  and  Li- 
verpool, have  a  monopoly  of  the  sale  of 
Peruvian  guano.  This,  perhaps,  is  not 
to  be  regretted,  as  what  comes  direct  from 
them  is  genuine,  and  otherwise  it  is  im- 
possible to  procure  an  unadulterated  ar- 
ticle, so  great  is  the  temptation  and  exten- 
sive the  use  of  the  article.  A  sample 
lately  imported  into  New-York  by  Messrs. 
A.  B.  Allen,  Watcr-st.,  N.  Y.,  and  ana- 
lyzed by  the  editor,  afforded  by  chemical 
examination  in  100  parts, 

Water T  83 

Organic  matter  and  salts  of  ammonia 

as  urate  oxalate  and  sulphate 69*79 

Phosphates  of  lime  and  magnesia  and 
ammonia  phosphate  of  magnesia. .  .17"60 

Lime -60 

Sulphuric  acid 3' 

Alkaline  salts,  chloride  of  sodium,  and 

traces  of  potass -48 

Sand 1-20 

100-00 

This  guano  was  capable  of  yielding  12& 
percent,  of  ammonia. 

The  following  analysis  of  a  good  sample 
of  Peruvian  guano  made  by  the  late  Mr. 
Fownes,  Englandj  affords  a  good  idea  of 
what  is  the  constitution  of  a  superior  ar- 
ticle in  100  parts : 

Azotized  animal  matter,  including 
urate  of  ammonia  and  other  ammo- 
niacal  salts,  together,  capahle  of  af- 
fording from  8  to  16  per  cent  of 
ammonia  by  slow  decomposition  in 
the  soil 50* 

Water 11- 

Phosphate  of  lime 25* 

"  of  ammonia,  oxalate  of  am- 
monia, phosphate  of  magnesia,  toge- 
ther, yielding  from  5  to  9  parts  of 
ammonia 13* 

Silica I- 

100' 


From  the  foregoing  analysis  its  valu- 
able character  is  evident.  This  is  sus- 
tained by  the  astonishing  and  generally 
profitable  results  which  follow  its  appli- 
cation, and  has  rendered  it,  though  of  re- 
cent introduction,  one  of  the  most  popular 
manures  in  this  country  and  Europe. 
It  has  been  known  and  appreciated  by 
the  Peruvians,  from  time  immemorial ; 
and  by  its  liberal  use,  combined  witn 
irrigation,  they  have  for  ages  produced 
the  most  abundant  crops  of  maize  and 
wheat.  It  was  not  used  agriculturally  in 
Europe  until  1840 ;  in  England  at  present 
400,000  tons  per  year  are  used. 

African  or  Ichaboe  and  Patagonian 
guano  have  been  brought  into  this  coun- 
try to  a  limited  extent.  They  have  been 
used  with  advantage,  but  are  by  no 
means  equal  to  the  Peruvian  variety. 
Those  guanos  have  been  accumulated  in 
damp  climates,  and  have  hence  under- 
gone decomposition,  so  that  most,  if  not 
all,  the  urate  of  ammonia  is  broken  up 
into  oxalate  of  ammonia — a  salt  far  less 
valuable  in  agriculture  :  even  this  is  dis- 
sipated and  washed  away  by  the  rains, 
so  that  the  proportion  of  "ammoniacal 
salts  falls  often  in  this  variety  below  20 
per  cent.,  leaving  the  phosphates  in  a 
corresponding  excess,  so  that  it  more  re- 
sembles bones  in  composition. 

Guano  was  first  introduced  into  the 
States  in  1825,  when  it  was  used  in  gar- 
dens, and  forgotten :  after  its  use  in 
England  it  was  again  re-imported.  Its 
application  here  was  but  slow  in  in- 
crease, yet  it  has  advanced,  and  the  de- 
mand for  this  year  will  probably  be  25,000 
tons.  Its  value  cannot  be  over-esti- 
mated, as  it  is  suitable  for  almost  all 
crops  and  soils,  but  is  perhaps  best 
adapted  for  sandy  loams.  From  2  to  5 
cwt.  is  a  proper  dressing.  It  is  better 
to  compost  it  with  five  times  its  bulk 
of  loam,  vegetable  mould,  or  with  char- 
coal or  gypsum.  Lime  or  ashes  must  be 
avoided  carefully,  as  the  ammonia  is  thus 
driven  off.  It  snould  be  kept  dry  and 
under  cover,  as  that  which  smells  strong- 
est is  losing  its  ammonia.  It  is  usually 
spread  broadcast  on  meadows  and  grain, 
or  placed  with  the  seeds  in  the  hill :  it 
develops  both  leaf  and  ear  wonderfully, 
and  hence  is  as  suitable  for  grain  as  for 
green  crops ;  it  ought  to  be  used  only 
in  autumn  or  in  spring  in  the  south. 
The  sun's  heat  is  too  great  for  summer 
application,  the  loss  of  ammonia  being 
very  great. 

GUDGEONS  are  the  ends  of  axles,  on 
which  they  work  and  rest.    In  water- 


230 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[gur 


■wheels  they  ought  to  be  strong  enough, 
but  not  so  large  as  to  increase  friction  un- 
necessarily. The  proportions  of  wrought 
iron  and  cast  iron  are  as  3  inches  to  3i 
or  8  to  9J. 

To  determine  their  diameter,  extract 
the  cube-root  of  the  weight  of  the  wa- 
ter-wheel,  in  hundred  weights,  and  the 
root  is  the  inches  for  the  diameter  in 
cast-iron ;  but  if  wrought-iron,  it  may 
be  as  14  to  9  less.  If  it  is  a  wooden 
axle,  multiply  the  diameter  in  feet  by 
the  width  in  feet,  and  add  half  the  square 
of  the  diameter :  then  the  cube-root  of 
this  sum  is  the  diameter  of  the  fit  gud- 
geon in  inches.  A  gudgeon  contains  in 
cwts.  the  cube  of  its  diameter  in  inches. 
GUM.  A  vegetable  product,  distin- 
guished by  solubility  in  water,  and  in- 
solubility in  alcohol :  it  is  tasteless  and 
inodorous.  Gum-arabic,  which  is  the 
produce  of  the  Acacia  vera,  may  be  taken 
as  a  sample  of  the  purest  form  of  gum. 
It  is  imported  from  Barbary  and  Morocco. 
Its  specific  gravity  is  1-45.  Its  solution 
is  viscid,  and  is  termed  mucilage.  Gum 
is  used  as  a  demulcent  in  medicine,  and 
for  giving  a  gloss  to  linens,  silks,  &c.  It 
consists  of  carbon  41*4,  oxygen  52*09, 
hydrogen  6-51 ;  or,  in  other  terms,  of 
41-4  charcoal  and  58-6  water. 

Guerin  has  analyzed  several  varieties 
of  gum.  Arabia,  which  constitutes  the 
greater  portion  of  gum-arabic,  is  com- 
posed of 

Carbon 43  81 

Oxygen 4985 

Hydrogen 6  20 

Azote 14 

100-00 
Gum-arabic  is  found  to  consist  of 

Arabin 7940 

Water 1760 

Ashes 3  00 

100  00 

Messrs.  Gay-Lussac  and  Thenard  found 
its  composition  to  be  : 

Arabin 8416 

Water 1343 

Ashes 2  41 

10000 

The  difference  of  water  found  depended 
upon  the  different  methods  of  analysis. 

The  dried  root  of  the  blue-bell  contains 
mucilage,  very  similar  to  gum-arabic. 

Gum  Senegal  is  less  soluble  than  gum- 
arabic,  and  deeper  in  color. 

GUM-RESIN.  An  exudation  from 
many  trees,  composed  of  a  mixture  of 


gum  and  resin,  or  of  a  substance  inter- 
mediate between  the  two. 

GUN.  Under  this  general  term  most 
of  the  species  of  fire-arms  are  included, 
the  pistol  and  mortar  being  almost  the 
only  exceptions.  Great  guns,  or  cannon, 
began  to  be  used  as  military  engines  about 
the  middle  of  the  14th  century ;  but 
small  guns,  or  muskets,  appear  to  have 
been  introduced  nearly  two  centuries 
later,  namely,  1521.  They  were  first  used 
by  the  Spanish  infantry  at  the  siege  of 
K'hege.  Muskets  were  at  first  of  a  very 
clumsy  construction,  being  so  heavy  that 
they  could  not  be  levelled  and  fired  from 
the  shoulder ;  accordingly  the  soldier  was 
provided  with  a  rest,  which  it  was  ne- 
cessary to  carry  along  with  him  and  plant 
in  the  ground  in  order  to  support  the 
weapon  before  it  could  be  used.  The 
gun  was  generally  fired  with  a  match ; 
sometimes  by  means  of  sparks  gene- 
rated by  the  revolution  of  a  notched 
wheel  of  steel,  placed  directly  above  the 
pan  containing  the  priming.  Muskets 
with  rests  were  employed  so  lately  as 
the  civil  wars  in  the  time  of  Charles  I. ; 
afterwards  a  lighter  matchlock  musket 
came  into  use  :  and  about  the  beginning 
of  the  last  century  the  troops  through- 
out Europe  were  armed  with  firelocks. 

Small  guns  were  invented  by  Swartz, 
a  German,  about  1378  ;  brought  into  use 
by  the  Venetians,  1382.  Cannon  were 
first  used  at  the  battle  of  Cressy,  1346  ; 
first  used  in  England  at  the  siege  of  Ber- 
wick, 1405  ;  first  cast  in  England,  1544 ; 
used  in  shipping  by  the  Venetians,  1539 ; 
before  they  were  only  used  to  batter 
walls.  Mohammed,  at  the  siege  of  Con- 
stantinople, employed  some  of  the  larg- 
est guns  ever  made  use  of  before  or 
since.  One  of  his  cannon  was  of  such 
enormous  size  as  to  require  70  yoke  of 
oxen  to  draw  it,  and  2000  men  to  man 
it.  It  discharged  a  ball  of  the  weight  of 
300  lbs.  The  report  waB  heard  to  a  great 
distance,  and  the  country  shaken  to  the 
distance  of  40  furlongs. 

The  barrel  forms  the  essential  part  of 
the  gun  ;  and  the  first  requisite  to  a 
good  barrel  is  toughness  in  the  material 
of  which  it  is  made,  for  safety  iu  using 
it  depends  mainly  on  this  quality.  The 
best  iron  for  the  formation  of  musket 
barrels  is  that  which  has  been  much 
worn,  and  toughened  by  the  loss  of  its 
fiery  particles ;  and,  accordingly,  old  horse 
stub-nails  are  much  in  request  for  this 

Eurpose,  and  sold  at  a  high  price  to  the 
arrel-forgers.    Formerly  the  best  gun- 
barrels  were  made  in  Spain ;   and  their 


gun] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


231 


superiority  was  attributed  to  the  excel- 
lency of  the  iron  made  use  of,  which 
consisted  almost  exclusively  of  stub-nails, 
and  the  old  shoes  of  horses  and  mules : 
but  the  barrels  now  made  in  this  coun- 
try are  not  inferior  to  those  of  any  coun- 
try in  the  world.  The  method  of  mak- 
ing the  barrel  is  this :  the  iron  is  first 
formed  into  a  thin  flexible  bar,  some- 
thing like  a  cooper's  hoop,  and  when 
heated  is  plied  or  twisted  round  a  man- 
dril, much  in  the  same  manner  as  a  rib- 
bon of  leather  is  turned  round  the  handle 
of  a  whip.  For  the  best  barrels  the 
breadth  of  the  bar  does  not  exceed  half 
an  inch ;  and  it  is  turned  round  the  man- 
dril in  such  a  manner  that  the  edges  are 
brought  close  together,  but  do  not  over- 
lap. In  this  position  it  is  wedded  by 
horizontal  strokes  with  the  hammer.  But 
in  common  guns  a  broader  bar  is  em- 
ployed ;  and  its  edges,  which  are  placed 
so  as  to  overlap  considerably,  are  welded 
down  on  each  other.  The  Damascus 
barrels,  prized  for  their  beauty,  though 
inferior  in  strength,  are  composed  of  iron 
and  steel  in  certain  proportions  laid 
crossways,  and  hammered  together  the 
whole  length  of  the  barrel.  After  the 
barrel  has  been  forged,  the  inside  is  ren- 
dered smooth  and  perfectly  cylindrical 
by  boring  it  with  a  bit,  or  rather  bits  of 
different  sizes  used  in  succession.  In  ri- 
fles a  certain  number  of  parallel  grooves, 
either  straight  or  slightly  twisted,  are  cut 
in  the  inside  of  the  barrel,  of  equal 
depth  and  fineness,  and  through  its  whole 
length.  The  exterior  is  smoothed  by 
turning  it  on  a  lathe. 

Mr.  Aaron  Eose,  of  Worcester,  Eng- 
land, has  just  enrolled  his  description  of 
a  new  method  of  manufacturing  twisted 
gun  barrels,  which  is  thus  described : — 
An  iron  or  steel  rod,  or  a  mixture  of 
both,  of  sufficient  length  and  thickness 
to  form  a  gun  or  pistol  barrel,  is  wound 
into  a  compact  coil,  and  then  placed  in 
an  anvil  having  a  semi-circular  groove, 
where  it  is  submitted  to  the  action  of  the 
tilt  hammer.  The  coil  is  then  submitted 
to  a  welding  heat  in  an  air  furnace,  then 
hammered  and  rolled,  a  stream  of  water 
being  used  in  both  cases  to  wash  away 
the  scale. 

The  tilt  hammer  has  a  groove  on  its 
face  corresponding  with  the  anvil  to  act 
upon  the  coil,  before  the  welding. 

Mr.  Vandenberg,  a  Flemish  gentleman, 
has  invented  a  new  gun  which  can  make 
six  and  eight  charges  per  minute,  carry- 
ing the  distance  of  2000  feet ;  the  ball 
weighs  about  one  ounce  and  a  quarter, 


and  the  powder  is  one-twelfth  the  weight 
of  the  ball.  An  ordinary  gun  requires 
three  times  more  powder,  the  ball  does 
not  weigh  half  an  ounce.  The  new  gun 
is  loaded  from  the  breech.  The  shape 
of  the  ball  is  round.  At  Utica,  N.  Y., 
the  new  rifle  of  Mr.  Milo  M.  Cass  dis- 
charged 24  balls  in  two  minutes  and  30 
seconds  ;  then  loading  with  26  cartridges 
in  4  minutes,  and  discharged  24  in  2  mi- 
nutes and  30  seconds, — thus  loading  once 
and  firing  48  shots  in  9  minutes,  The 
shooting  was  very  accurate,  considering 
the  rapidity,  and  the  performance  of  the 
gun  gave  great  satisfaction  to  those  pre- 
sent." The  barrel  of  the  gun  was  so  little 
heated  after  the  first  24  discharges,  that 
it  was  immediately  loaded  and  again  fired 
the  same  number  of  times.  _ 

The  Air-Gun  is  a  machine  in  which 
highly-compressed  air  is  substituted  for 
gunpowder  to  expel  the  ball,  which  will 
be  projected  forward  with  greater  or  less 
velocity,  according  to  the  state  of  conden- 
sation and  the  weight  of  the  body  pro- 
jected. The  effect  will,  therefore,  be 
similar  to  that  of  a  gun  charged  with 
gunpowder,  for  inflamed  gunpowder  is 
nothing  more  than  air  very  greatly  con- 
densed, so  that  the  two  forces  are  exactly 
similar.  There  is  this  important  con- 
sideration to  be  attended  to,  namely,  that 
the  velocities  with  which  balls  are  im- 
pelled are  directly  proportional  to  the 
square  root  of  the  forces  ;  so  that  if  the 
air  in  an  air-gun  be  condensed  only  ten 
times,  the  velocity  will  be  equal  to  one- 
tenth  of  that  arising  from  gunpowder ; 
if  condensed  twenty  times,  the  velocity 
would  be  one-seventh  that  of  gunpow- 
der, and  so  on.  Air-guns,  however,  pro- 
ject their  balls  with  a  much  greater  ve- 
locity than  that  assigned  above  ;  and  for 
this  reason,  as  the  reservoir  or  magazine 
of  condensed  air  is  commonly  very  large 
in  proportion  to  the  tube  which  contains 
the  ball,  its  density  is  very  little  altered 
by  passing  through  that  narrow  tube, 
and  consequently  the  ball  is  urged  all 
the  way  by  nearly  the  same  force  as  at 
the  first  instant ;  whereas  the  elastic  fluid 
arising  from  inflamed  gunpowder  is  but 
very  small  indeed  in  proportion  to  the 
tube  or  barrel  of  the  gun,  and  therefore, 
by  dilating  into  a  comparatively  large 
space,  as  it  urges  the  ball  along  the  bar- 
rel, its  force  is  proportionally  weakened, 
and  it  always  acts  less  and  less  on  the 
ball  in  the  tube. 

An  air-gun  recently  invented  by  Mr. 
Shaw,  of  Glassop,  England,  is  one  of 
much  simplicity  of  construct  >n.    It  has 


232 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


not  the  effective  force  of  gunpowder,  but 
it  will  enable  a  sportsman  to  amuse  him- 
self at  but  little  expense,  and  will  do 
execution,  too,  at  considerable  distance 
from  the  mark.  The  air  that  projects 
the  bullet  is  condensed  by  a  piston,  which 
draws  out  a  strong  India  rubber  spring, 
which,  when  it  is  set  free,  suddenly 
draws  up  the  piston,  condensing  the  air 
in  the  air  chamber,  and  impelling  it 
against  the  bullet  to  discharge  it  with 
considerable  velocity  and  power. 

GUNPOWDER  is  explosive  nitre 
brought  into  intimate  contact  with  in- 
flammable sulphur  and  charcoal.  75  of 
the  nitre,  16  of  charcoal,  and  9  of  sul- 
phur, pounded  as  paste  with  wooden 
mortars,  fixed  in  a  wheel  for  12  hours. 
It  is  granulated  by  being  forced  through 
a  sieve,  and  glazed  by  agitation  in  a 
cask.  The  gas  formed  by  an  explosion 
is  2  volumes  of  nitrogen  to  1  carbonic 
acid. 

Dr.  Ure  has  analysed  various  samples 
of  gunpowder, "and  the  following  are  the 
results  of  his  investigations  : — 

Waltham  Abbey,  nitre  74*5,  charcoal 
14-4,  sulphur  10*0,  water  1*1. 

Hall,  Dartford,  nitre  76-2,  charcoal  14-0, 
sulphur  9*0,  water  0-5. 

Pigou  and  Wilks,  nitre  77*4,  charcoal 
13-5,  sulphur  8*5,  water  0*6. 

Curtis  and  Harvey,  nitre  76*7,  charcoal 
12*5,  sulphur  9*0,  water  1*1. 

Battle  gunpowder,  nitre  77*0,  charcoal 
13-5,  sulphur  8-0,  water  0-8. 

Charcoal,  sulphur,  and  nitre,  being 
ready  for  manufacturing  into  gunpowder. 
1st.  They  are  separately  ground  to  a  fine 
powder,  which  is  passed  through  proper 
silk  sieves  or  bolting  machines.  2d. 
They  are  mixed  together  in  the  proper 
proportions.  3d.  The  composition  is 
then  sent  to  the  gunpowder  mill,  which 
consists  of  two  edge-stones  of  a  calca- 
reous kind,  turning  by  means  of  a  hori- 
zontal shaft  on  a  bed-stone  of  the  same 
nature  ;  incapable  of  affording  sparks  by 
collision  with  steel.  On  this  bed-stone 
the  composition  is  spread,  and  moistened 
with  as  small  a  quantity  of  water  as  will, 
in  conjunction  with  the  weight  of  the  re- 
volving stones,  bring  it  into  a  proper 
body  of  cake,  but  by  no  means  to  a  pasty 
utate.  The  line  of  contact  of  the  rolling 
edge-stone  is  constantly  preceded  by  a 
hard  copper  scraper,  which  goes  round 
with  the  wheel,  regularly  collecting  the 
caking-mass,  and  bringing  it  into  the 
track  of  the  stone. 

The  materials  for  gunpowder  are  ground 
by  a  wheel  revolving  in  a  trough.    They 


are  then  moistened  and  put  into  boxes 
with  holes  in  the  bottoms.  The  boxes 
are  placed  in  a  circular  frame  suspended 
by  cords,  and  briskly  agitated  by  a  crank, 
when  the  paste  passes  through  the  holes 
as  corns  ot  powder.  These  are  afterwards 
polished  by  being  revolved  in  a  barrel, 
dried  by  vessels  of  steam,  and  packed  for 
sale. 

Gunpowder  to  be  good  should  ba 
quick,  strong,  free  from  impurity,  and 
not  liable  to  absorb  moisture.  The  gene- 
ral method  of  trying  the  purity  is  by 
burning  it  on  clean  white  paper  :  two  or 
three  small  heaps  are  made  near  each 
other,  and  one  of  them  is  fired ;  if  the 
smoke  rises  perpendicularly,  and  there 
be  no  feculent  matter  left  on  the  paper, 
nor  the  other  heaps  fired,  it  is  considered 
that  the  ingredients  were  of  a  good  qual- 
ity, and  well  compounded.  If  the  other 
heaps  are  fired,  the  paper  burnt,  or  a 
dirty  residuum  left,  it  may  be  supposed 
that  the  nitre  was  impure,  or  that  the 
charcoal  was  not  completely  pulverized. 

M.  Angendre,  Assayer  at  the  Mint  of 
Constantinople,  has  addressed  a  commu- 
nication to  the  Academy  of  Sciences  at 
Paris,  describing  the  discovery  of  a  new 
explosive  powder,  having  for  its  base  the 
prussiate  of  potash.  The  composition  is 
(by  weight)  crystallized  dry  yellow  prus- 
siate of  potash  one  part,  dry  white  sugar 
one  part,  chlorate  of  potash  one  part. 
These  three  substances  are  reduced  se- 
parately in  a  mortar  to  fine  powder,  and 
then  intimately  mixed  by  hand.  In  ope- 
rating on  any  quantity,  the  mixture  is 
moistened  with  a  very  little  water,  and 
beaten  in  a  bronze  mortar  with  a  wooden 
pestle.  It  is  not  necessary  that  the  mix- 
ture should  be  as  intimate  as  in  the  case 
of  ordinary  gunpowder, — a  quarter  of  an 
hour  will  suffice  to  mix  it.  It  is  then 
grained  in  the  ordinary  manner,  and 
dried  in  the  air.  The  discoverer,  M:  An- 
gendre, considers  that  this  powder  is 
equal  in  strength  to  three  times  its 
weight  of  the  common  kind.  It  is  easily 
made,  and  the  substances  of  which  it  is 
composed  have  a  fixed  and  determined 
composition.  It  is  not  injured  either  in 
dry  or  damp  air,  but  it  is  not  suitable  for 
small  fire-arms,  only  for  those  of  cast- 
iron,  and  it  will  answer  a  good  purpose 
in  blasting.  The  reason  why  it  is  not 
good  for  any  fire-arms  of  steel  is  owing 
to  the  chlorate  of  potash,  which  oxidizes 
steel  with  great  rapidity.  Some  of  our 
civil  engineers  may  find  this  powder  in- 
valuable for  blasting,  as  they  can  make 
it  themselves,  it  being  equally  as  effec- 


gun] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


233 


tive  when  in  a  state  of  powder  as  when 
grained.  No  other  powder  must  he  al- 
lowed to  mix  with  it,  for  in  ramming  the 
hore  for  a  hlast,  the  friction  of  the  parti- 
cles of  the  old  powder  will  be  ready  to 
ignite  the  new  kind. 

GUNTER'S  CHAIN,  so  called  from 
its  reputed  inventor,  is  the  chain  com- 
monly used  for  measuring  land.  It  is 
66  feet  or  4  poles  in  length,  and  is  divided 
into  100  links,  each  of  which  is  joined 
to  the  adjacent  one  by  three  rings  ;  and 
the  length  of  each  link,  including  the 
connecting  rings,  is  7-92  inches.  The 
advantage  of  this  measure  consists  in  the 
facility  which  it  affords  to  numerical  cal- 
culation. The  English  acre  contains 
4840  square  yards ;  and  Gunter's  chain 
being  22  yards  in  length,  the  square  ot 
which  is  484,  it  follows  that  a  square 
chain  is  exactly  the  tenth  part  of  an  acre. 
A  square  chain  again  contains  10,000 
square  linics,  so  that  100,000  square  links 
are  equal  to  an  acre ;  consequently,  the 
contents  of  a  field  being  cast  up  in 
square  links,  it  is  only  necessary  to  di- 
vide by  100,000,  or  to  cut  off  the  last  five 
figures,  to  obtain  the  contents  expressed 
in  acres. 

GUNTEE'S  LINE.  A  logarithmic 
line  engraved  on  scales,  sectors,  &c, 
serving  to  perform  the  multiplication 
and  division  of  numhers  instrumentally, 
as  a  table  of  logarithms  does  arithmeti- 
cally. The  numbers  are  usually  drawn 
on  two  separate  rulers  sliding  against 
each  other.  In  rough  calculation  this  line 
affords  considerable  facilities. 

GUNTER'S  QUADRANT.  A  quad- 
rant of  a  peculiar  kind  adapted  to  the 
problems  of  finding  the  hour  of  the  day, 
the  sun's  azimuth,  and  other  common 
problems  of  the  sphere. 

GUN  COTTON  was  first  announced 
by  Professor  Schonbein,  and  shown  by 
him  to  the  Natural  History  Society  of 
Basle  in  1846.  Shortly  after  this  Bcelt- 
zer,  Otto,  and  Morel,  discovered  similar 
explosive  compounds,  all  of  which  may 
fairly  be  traced  to  Pelouse  and  Brac- 
caurd's  discovery  of  Xyloidine.  It  has 
been  looked  on  as  identical  with  the  lat- 
ter, but  n^t  correctly,  for  gun  cotton  dis- 
solves in  acetic  acid,  while  xyloidine 
does  not.  Schonbein  made  it  originally 
by  dipping  cotton  in  nitric  acid,  sp.  gr. 
1*49,  which  after  immersion  for  ten  mi- 
nutes it  was  rinsed  in  a  large  quantity 
of  cold  Avater,  to  free  it  from  any  adher- 
ing acid  ;  and  then  carefully  dried.  Dr. 
Ellet,  Professor  of  Chemistry  in  Univer- 
nity  of  South  Carolina,  adopted  as  an  im- 


provement the  use  of  sulphuric  acid, 
with  the  view  of  keeping  the  nitric  acid 
concentrated.  Dr.  Taylor,  of  London, 
adopted  a  similar  plan ;  nitre  was  after- 
wards added  to  the  mixed  acids.  In 
order  to  obtain  a  good  gun  cotton  it  is 
necessary 

1st.  To  steep  purified  cotton  in  a  mix- 
ture of  equal  parts  of  nitric  and  sul- 
phuric acids. 

2d.  The  duration  of  immersion  is  not 
important :  the  best  samples  have  been 
ten  minutes  steeped. 

3d.  A  mixture  may  be  used  in  which 
cotton  has  been  previously  immersed,  re- 
viving it  if  necessary. 

4th.  The  cotton  must  not  be  above  the 
level  of  the  liquid. 

5th.  It  must  be  dried  slowly,  and  not 
exposed,  especially  when  damp,  to  a  tem- 
perature exceeding  100°. 

6th.  By  washing  in  water  saturated 
with  nitre  or  chlorate  of  potass  its  power 
is  a  little  increased,  but  it  is  not  worth  the 
additional  expense. 

Burned  on  the  hand  it  causes  no  sen- 
sible pain,  leaves  no  stain,  and  produces 
no  smoke  ;  dipped  in  water  and  pressed, 
and  afterwards  dried  between  two  leaves 
of  blotting  paper,  it  preserves  its  fulmi- 
nating properties.  It  explodes  on  being 
heated  to  350°,  or  on  bringing  a  red  hot 
body  in  contact  with  it :  a  dry  piece  of 
the  cotton  laid  upon  gunpowder  may  be 
exploded  without  igniting  the  powder. 
This  is  due  to  the  rapidity  of  the  explo- 
sion. Mr.  E,  F.  Teschemacher  and  Mr. 
R.  Forrett  have  found  gun  cotton  to  con- 
sist uniformly  of  nitric  acid  and  liquin, 
in  the  proportion  of  60  of  the  former  to 
40  of  the  latter.  Properly  exploded  in  a 
narrow  glass  tube  so  as  to  collect  the 
gaseous  product,  52-33  grains  of  the  cot 
ton  were  found  to  give  100  c.  i.  of  gas, 
of  which  the  composition  was  remark- 
able, consisting  of 

Carbonic  acid 14-286,  or  2  vols. 

Cyanogen 7143,  or  1  vol. 

Nitric  oxide 35-715,  or  5  vols. 

Carbonic  oxide 35915,  or  5  vols. 

Nitrogen 7-143,  or  1  vol. 

Besides  which  a  sublimate  of  oxalic  acid 
and  a  quantity  of  water  was  formed  in 
the  combustion. 

Exposed  to  a  dry  heat,  between  200° 
and  300°,  it  became  brown,  and  lost  its 
explosive  property.  Steaming  it,  seems 
to  increase  its  power. 

Examined  under  the  microscope,  there 
is  no  difference  visible  betAveen  cotton  so 
prepared  and  that  unacted  on  by  acid. 
Under  the  action  of  polarized  light  there 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[gut 


is,  however,  a  marked  difference.  The 
fibres  of  ordinary  cotton  are  then  bril- 
liantly illuminated  on  a  dark  colored 
ground,  while  the  gun  cotton  is  dark  and 
colorless,  and  invisible  at  every  half  turn 
of  the  prism. 

In  practice,  it  has  not  fulfilled  all  that 
was  originally  predicted  of  it;  it  is  unfit 
for  gunnery  and  fire-arms  of  any  kind, 
but  is  admirably  adapted  for  mining  and 
blasting. 

The  advantages  of  its  use  are:  its 
cleanliness,  the  rapid  combustion,  and 
non  residuum  ;  the  absence  of  any  bad 
smell ;  its  lightness :  the  possibility  of 
handling  it  without  danger  at  a  distance 
from  the  fire ;  the  absence  of  dust,  and 
its  indisputable  force,  which  is  triple  that 
of  gunpowder  of  equal  weight.  The 
disadvantages  are :  bulk,  increased  in- 
flammability, the  disadvantage  of  evolv- 
ing vapor  during  its  explosion ;  it  wets 
the  guns  and  cannon  just  as  gunpowder 
/outs  them. 

Gun  cotton  dissolved  in  ether  forms  a 
good  varnish  for  covering  wounds,  or 
giving  a  thin  film  to  cover  any  surface, 
and  is  a  powerful  deoxidizer,  reducing 
salts  of  silver  and  a  few  other  metals  very 
rapid,y. 

GIjTTA  PERCH  A,  or  Gutta  Tvban. 
The  Malay  name  for  the  concrete  juice  of 
a  large  forest  tree :  one  of  the  Sapoteae — a 
native  of  Borneo,  Malacca,  and  the 
neighboring  countries.  It  is  chiefly 
brought  from  Singapore :  it  was  used  by 
the  natives  as  a  substitute  for  horn  and 
wood,  to  make  handles  for  knives  and 
choppers.  The  juice  is  obtained  by  cut- 
ting down  the  tree,  and  allowing  the 
juice  to  exude  from  the  cut  end.  This 
is  a  most  wasteful  proceeding,  as  the 
number  of  trees  must  shortly  be  so 
limited  as  to  destroy  the  supply  of  the 
article.  Mr.  Brooke,  of  Borneo,  says  the 
tree  is  often  six  feet  in  diameter  at  Sara- 
wak, and  is  believed  to  be  plentiful  all 
over  Borneo,  and  probably  at  the  thou- 
sand islands  that  cluster  to  the  south  of 
the  Straits  of  Singapore.  Its  frequency 
is  proved  by  the  circumstance  that  seve- 
ral hundred  tons  of  the  Gutta  Percha 
have  been  annually  exported  from  Singa- 
pore since  1842,  when  the  substance  first 
came  into  notice.  There  is  reason,  how- 
ever, to  fear  that  the  supply  must  shortly 
decrease,  and  the  price  he  raised,  from 
the  wasteful  mode  in  which  the  natives 
collect  it,  often  sacrificing  a  noble  tree,  of 
from  fifty  to  one  hundred  years  growth, 
for  the  sake  of  twenty  or  thirty  pounds 
of  gum,  which  is  the  largest  quantity 


any  one  trunk  ever  affords.  The  juice 
might,  in  all  likelihood,  be  obtained  from 
the  Percha,  as  from  other  trees,  by  tap- 
ping, and  thus  procuring  a  smaller  por- 
tion for  several  successive  years;  but 
this  process  is  too  slow  for  the  Malayans, 
and  is  also  less  likely  to  be  adnpted  be- 
cause the  forests  are  common  property. 
The  people  fell  the  tree,  strip  off  its 
bark,  and  collect  its  milky  juice  in  a 
trough  formed  of  the  hollow  stem  of  the 
plantain  leaf,  when,  being  exposed  to  the 
air,  it  soon  coagulates. 

As  it  comes  to  market,  it  is  a  dirty 
white,  pinkish,  solid,  opaque,  having  but 
little  smell,  and  insoluble  in  water ;  it 
has  a  silky,  fibrous  texture,  especially 
when  drawn  out.  It  feels  smooth  and 
greasy  between  the  fingers.  Below  50° 
it  is  hard,  tough,  and  partially  flexible, 
when  thin  like  horn ;  between  50°  and 
70°,  it  is  elastic,  and  more  flexible,  yet 
still  tough  and  stiff  2  between  140°  and 
160°,  .it  becomes  quite  soft  and  plastic, 
and  loses  its  tenacity.  In  this  stato 
pieces  of  it  may  be  joined,  all  that  is  ne- 
cessary being  to  press  them  together, 
when  they  form  a  perfect  joint.  By  cut- 
ting it  up  in  fragments,  and  boiling  in 
hot  water,  most  of  the  impurities  may 
be  removed.  When  thus  purified  by 
cooling,  it  passes  into  a  solid  mass ; 
when  softened  by  either  hot  water  or 
simple  dry  heat,  it  may  be  molded  into 
any  shape,  or  pressed  into  a  pattern  :  as 
it  cools,  it  gradually  recovers  its  tough- 
ness and  rigidity.  In  consequence  of 
this  it  forms  perfect  casts  of  coins,  me- 
dals, &c,  which,  if  carefully  made,  have 
all  the  sharpness  of  sulphur  without  its 
brittleness.  When  hot,  it  is  easily  cut 
with  the  knife  or  saw,  but  when  cold  it 
is  difficult  to  cut  it,  without  wetting  the 
tool  with  cold  water.  It  is  lighter  than 
water,  and  floats  on  it :  the  spec,  gravity 
being  when  pure  -9791.  In  its  chemical 
relations  it  closely  resembles  caoutchouc, 
and  is  isomeric  with  it :  it  differs,  how- 
ever, in  some  physical  properties.  By 
destructive  distillation  it  yields  similar 
products,  affording  a  clear  limpid  oil  of 
a  mixed  composition  between  360°  and 
390°.  It  is  insoluble  in  alcohol  and 
water,  dissolves  partially  in  oil  of  tur- 
pentine, ether,  and  perfectly  in  cold 
naphtha,  benzole,  sulphuret  of  carbon, 
and  caoutehicine.  Or  these  the  benzole 
is  the  fittest;  when  dissolved  in  it  by 
the  aid  of  gentle  heat,  and  then  poured 
out  on  a  glass  plate  to  evaporate  the 
benzole,  the  gutta  percha  is  left  behind 
in  the  form  of  a  white  film  or  skin.    In 


gut] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


235 


this  way  very  thin  sheets  of  this  sub- 
stance is  obtained.  Souberain  has  made 
an  ultimate  analysis  of  it,  which  yielded 
to  him  carbon  87-8,  hydrogen  12-2.  Mr. 
Crane  believes  the  crude  article  to  be 
composed  Of  two  substances:  1st,  the 
pure  white  gntta ;  and  2d,  a  brown  color- 
ing material.    Benzole  separates  them. 

Dr.  Montgomerie  suggests,  among  the 
less  immediately  obvious  uses  to  which 
gntta  percha  is  applicable,  that  of  mak- 
ing raised  type  for  the  blind,  and  em- 
bossed maps  for  the  same  unfortunate 
beings :  it  takes  a  clear,  sharp  impres- 
sion, and  is  also  tough  and  durable ;  he 
thinks  it  would  likewise  be  found  ser- 
viceable in  stopping  decayed  teeth. 

G.  Hancock,  Esq.,  has  taken  out  a  pa- 
tent for  improving  the  manufacture  of 
gntta  percha.  He  suggests  several  me- 
thods of  purifying  the  substance,  which 
generally  comes  here  much  mixed  with 
extraneous  matter.  It  may  be  dissolved 
by  heat  and  strained,  or  passed  through 
a  screw  press,  or  melted  by  the  addition 
of  rectified  oil  of  turpentine ;  and,  after 
filtering  through  flannel  or  felt,  the  sol- 
vent may  be  evaporated.  In  every  case 
the  gutta  percha  should  form  a  residuum 
of  the  consistency  of  dough  or  putty — 
this  plastic  state  being  gained  by  the 
maintenance  of  a  suitable  temperature 
during  the  above  process. 

Mr.  Hancock  would  combine  gutta 
percha  with  caoutchouc,  and  a  substance 
called  gintawan  (we  have  no  clue  to  what 
this  gintawan  may  be),  in  order  to  form 
an  elastic  material  impervious  to  water  ; 
varying  the  proportions  according  to  the 
greater  or  less  degree  of  hardness  or 
elasticity  required  for  making  elastic 
bands — a  compound  is  used  where  50 
parts  of  gutta  percha  are  combined  with 
24  of  gintawan,  20  of  caoutchouc,  and  6 
of  orpiment.  From  a  mixture  of  these, 
Mr.  Hancock  also  prepares  a  light,  po- 
rous, and  spongy  material,  suited  for 
stuffing  or  forming  the  seats  of  chairs, 
cushions,  mattresses,  saddles,  &c. ;  like- 
wise, springs  of  clocks,  clasps,  belts, 
garters,  and  strings.  Wherever  the  re- 
quisite is  flexibility  and  elasticity,  then 
the  quantity  of  gutta  percha  should  be 
diminished,  and  increased  where  firm- 
ness is  wanted.  By  prolonging  the  pro- 
cess much  hardness  may  be  acquired, 
and  moulds  and  balls  of  gutta  percha 
will  bear  turning  in  the  lathe,  like  wood 
or  ivory.  The  material  is  also  applica- 
ble to  useful  and  ornamental  purposes, 
as  picture  frames,  door  handles,  walking 
sticks,  chessmen,  handles  of  swords,  and 


knives,  buttons,  combs,  flutes,  &c,  &c. 
By  the  admixture  of  sulphuric  acid,  or 
of  a  tenth  or  larger  part  of  vegetable  wax 
or  tallow,  any  degree  of  solubility,  pli- 
ancy, and  softness,  may  be  acquired ;  or 
the  composition  may  be  used  as  varnish 
to  cover  other  materials,  concealing  any 
odor,  and  imparting  a  surface  impervious 
to  water.  In  printing  silks  and  cottons 
it  is  useful,  as  it  amalgamates  readily 
with  colors.  The  applications  of  gutta 
percha  are  endless  :  it  makes  good  tubes 
lor  conveying  water  or  gases ;  speaking 
tubes,  and  hose  ;  drinking  vessels,  pitch- 
ers, basins,  and  other  domestic  articles. 
An  extensive  use'  is  as  soles  for  shoes, 
which  are  fastened  to  the  clean  and 
rasped  leather  sole  by  a  fluid  varnish 
made  of  the  gutta  dissolved  in  coal  tar. 
A  solution  of  it  forms  a  good  varnish  for 
wires  or  cordage,  or  any  substance  which 
it  may  be  desirable  to  protect  or  insulate. 
It  is  sulphurized  occasionally,  and  some- 
times combined  with  caoutchouc.  At 
the  American  Gutta  Percha  Company, 
having  their  factory  in  Brooklyn,  !N.  Y., 
the  various  modifications  and  articles  of 
which  this  substance  is  susceptible  of 
being  applied  to,  is  interestingly  demon- 
strated. 

Gutta  percha  is  of  the  most  powerful 
negative  electrics,  and  may  be  used  for 
insulating  positive  surfaces,  or  for  de- 
veloping quantities  in  place  of  the  glass 
cylinder.  A  thin  sheet  of  this  substance 
wrapped  round  a  bottle  or  wooden  cylin- 
der, and  turned  by  hand,  gives  a  copious 
supply  of  the  fluid  for  experiment. 

Previous  to  1844,  the  very  name  of 
gutta  percha  was  unknown  to  European 
commerce.  In  that  year  two  cwt.  of  it 
was  shipped,  experimentally,  from  Sing- 
apore. In  the  first  four  and  a  half  years 
of  the  trade,  21,598  pieuls  of  gutta  percha 
valued  at  $274,190,  were_  shipped  at, 
Singapore,  the  whole  of  which  were  sent 
to  England,  with  the  exception  of  15 
pieuls  to  Mauritius,  470  to  the  Continent 
of  Europe,  and  922  to  the  United  States. 
But  this  rapid  growth  of  the  new  trade 
conveys  only  a  faint  idea  of  the  commo- 
tion it  created  among  the  native  inhabi- 
tants of  the  Indian  Archipelago.  The 
jungles  of  Johore  were  the  scenes  of  the 
earliest  gatherings,  and  they  were  soon 
ransacked,  in  every  direction,  by  parties 
of  Malays  and  Chinese,  while  the  indi- 
genous population  gave  themselves  up 
to  the  search  with  a  unanimity  and  zeal 
only  to  be  equalled  by  that  which  made 
railway  jobbers  of  every  man,  woman, 
and  ciiifd  in '  England,  about  the  same 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


f< 


time.  The  knowledge  of  the  article  stir- 
ring the  avidity  of  gatherers,  gradually 
spread  from  Singapore  northward  as  far 
as  Penang,  southward  along  the  east 
coast  of  Sumatra  to  Java,  eastward  to 
Borneo,  where  it  was  found  at  Brune, 
Sarawak  and  Pontianak  on  the  west  coast 
at  Keti,  and  Passe  on  the  east. 

GYPSUM.  Sulphate  of  lime,  alabaster ; 
plaster  of  Paris.  Plaster.  This  sub- 
stance is  found  in  three  geological  situa- 
tions in  the  crust  of  the  earth  :  1st,  among 
the  early  secondary  rocks ;  2d,  in  the 
new  red  sandstone  formations,  and  above 
the  chalk  in  the  tertiary  beds.  The 
gypsum  of  England  is'  found  in  the  new 
red  sandstone,  that  of  France  in  the  ter- 
tiary beds,  and  that  of  this  country  is 
chiefly  in  the  secondary  formation.  In 
the  State  of  New- York  are  the  best  de- 
veloped beds  of  gypsum  as  yet  explored 
in  this  country,  where  they  are  found  in 
the  beds  known  to  correspond  with  the 
tipper  Silurian  strata  of  English  geolo- 
gists. It  extends  over  the  central  and 
western  portions  of  the  State  in  a  belt 
extending  from  east  to  west,  where  it 
thickens  as  it  advances  until  it  reaches 
Ontario  county,  where  its  greatest  purity 
and  development  appears  to  exist.  It  is 
quarried  extensively  in  Cayuga,  Yates, 
and  Ontario  county.  The  purest  varie- 
ties consist  of  the  elements  of  the  crys- 
tallized selenite  or  alabaster,  viz. : 

Sulphuric  acid 40 

Lime 28 

Water 18 

In  86  parts. 

But  the  rock  gypsum  is  never  so  pure ; 
it  contains  aluminous  or  argillaceous  clay, 
and  variable  quantities  ot  carbonate  of 
lime  and  magnesia,  soluble  salts,  and 
silica.  The  Editor  of  this  work  having 
occasion  to  examine  the  soils  and  mine- 
rals of  Seneca  county,  N.  Y.,  found  the 
composition  of  the  rock  gypsum  to  be  as 
follows  in  100  parts. 

Water 660 

Carbonate  oflime  17-40 

Carbonate  of  magnesia 9-80 

Insoluble  silicates  and  sand 39  60 

Salis  of  alkalies  soluble  in  water.      '40 
Sulphate  of  lime 2620 

10000 

The  gypsum  of  Ontario  county  is  pur- 
er, and  is  fit  for  application  in  the  arts, 
which  the  above  is  not.  These  beds  of 
gypsum  occur  chiefly  in  isolated  masses, 
appearing  as  if  they  had  crystallized  out 
of  a  plastic  moist  clay,  and  are  generally 


surrounded  by  a  gypseous  marl  made  up 
of  the  carbonates  of  lime  and  magnesia 
and  sulphate  of  lime.  These  marls,  as 
well  as  the  above  impure  gypsum,  are 
admirably  adapted  for  agricultural  use 
as  amending  manures,  and  are  not  used 
at  all  to  the  extent  which  their  value 
would  justify. 

The  most  interesting  gypsums  in  a 
general  point  of  view  are  certainly  the 
tertiary,  or  those  of  the  plains,  or  hills  of 
comparatively  modern  formation.  They 
are  characterized  by  the  presence  of  fos- 
sil bones  of  extinct  animals,  both  mam- 
mifera  and  birds,  by  shells,  and  a  large 
proportion  of  carbonate  of  lime,  which 
gives  them  the  property  of  effervescing 
with  acids,  and  the  title  of  limestone 
gypsums.  Such  are  the  gypsums  of  the 
environs  of  Paris,  as  at  the  heights  of 
Montmartre,  which  contain  crystallized 
sulphate  of  lime  in  many  forms,  but 
most  commonly  the  lenticular  and  lance- 
shaped. 

Sulphate  of  lime  occurs  either  as  a 
dense  compound  without  water,  and  is 
called  anhydrite  from  that  circumstance, 
or  with  combined  water,  which  is  its 
most  ordinary  state.  Of  the  latter  there 
are  six  sub-species ;  sparry  gypsum  or 
selenite  in  a  variety  of  crystalline  forms  ; 
the  foliated  granular ;  the  compact :  the 
fibrous  ;  the  scaly  foliated  ;  the  earthy. 
<  The  prevailing  color  is  white,  with  va- 
rious shades  of  gray,  blue,  red,  and  yel- 
low. More  or  less  translucent.  Soft, 
sectile,  yielding  to  the  nail.  Specific 
gravity  2-2.  Water  dissolves  about  one 
five-hundredth  part  of  its  weight  of  gyp- 
sum, when  it  acquires  the  quality  of  hard- 
ness, with  the  characteristic  selenitic 
taste.  When  exposed  on  red  hot  coals, 
it  decrepitates,  becomes  white,  and  splits 
into  a  great  many  brittle  plates.  At  the 
heat  of  a  baker's  oven,  or  about  400° 
Fahr.,  the  combined  water  of  gypsum 
escapes  with  a  species  of  ebullition.  At 
a  higher  temperature  the  particles  get 
indurated.  When  rightly  calcined  and 
pulverized,  gypsum  is  mixed  with  water 
to  the  consistence  of  cream,  and  poured 
into  moulds  by  the  manufacturers  of 
stucco  ornaments  and  statues.  A  spe- 
cies of  rapid  crystallization  ensues,  and 
the  thin  paste  soon  acquires  a  solid  con- 
sistence, which  is  increased  by  drying 
the  figure  in  proper  stoves.  During  the 
consolidation  of  the  plaster,  its  volume 
expands  into  the  finest  lines  of  the 
mould,  so  as  to  give  a  sharp  and  faithful 
impression. 

The  plaster  stone  of  the  Paris  basin 


UAl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


23' 


contains  about  12  per  cent,  of  carbonate  , 
of  lime.  This  body,  ground  and  mixed  j 
with  water,  forms  an  adhesive  mortar  i 
much  used  in  building,  as  it  fixes  very 
speedily.  Works  executed  with  pure 
gypsum  never  become  so  hard  as  those 
made  with  the  calcareous  kind;  and 
hence  it  might  be  proper  to  add  a  certain 
portion  of  white  slaked  lime  to  our  cal- 
cined gypsum,  in  order  to  give  the  stuc- 
eo  this  valuable  property.  Colored  stuc- 
cos  of  great  solidity  are  made  by  adding 
to  a  clear  solution  of  glue  any  desired 
coloring  tincture,  and  mixing  in  the  pro- 
per quantity  of  the  calcined  calcareous 
gypsum. 

The  compact,  fine-grained,  gypseous 
alabaster  is  often  cut  into  various  orna- 
mental figures,  such  as  vases,  statuary 
groups,  <fec,  which  take  a  high  polish 
and  look  beautiful,  but  from  their  soft- 
ness are  easily  injured,  and  require  to 
be  kept  enclosed  within  a  glass  shade. 

In  America  and  France,  the  virtues  of 
gypsum  in  fertilizing  land  have  been 
highly  extolled. 

Pure  gypsum  consists  of  lime  28,  sul- 
phuric acid  40,  water  18,  which  are  the 
respective  weights  of  its  prime  equiva- 
lent parts. 

M.  Gay  Lussac,  in  a  short  notice  on 
the   setting  of  gypsum,    says  that  the 

{>urest  plasters  arc  those  which  harden 
east,  and  that  the  addition  of  lime  is  of 
no  use  toward  promoting  their  solidity, 
nor  can  the  heat  proper  for  boiling  gyp- 
N»nm  ever  expel  the  carbonic  acid  gas 
from  the  calcareous  carbonate  present  in 
the  gypsum  of  Montmartre.  He  con- 
ceives that  a  hard  plaster-stone  having 
lost  its  water,  will  resume  more  solidity 
in  returning  to  its  first  state  than  a  plas- 
ter-stone naturally  tender  or  soft ;  and 
that  it  is  the  primitive  molecular  ar- 
rangement which  is  regenerated. 

Franklin  was  the  first  to  call  public  at- 
tention to  the  use  of  gypsum  as  a  ma- 
nure, and  by  the  experiment  of  sowing 
it  in  the  form  of  letters  on  a  field, 
which  when  the  grass  grew  could  be  read 
by  its  superior  growth  and  verdure, 
tested  fully  its  value.  It  is  now  justly 
considered  indispensable  to  good  farm- 
ing, but  it  exerts  its  chief  value  only  on 
dry  or  drained  soils.  Sands  and  loams 
feel  its  influence  at  once.  Two  pecks 
on  sandy  soils  and  fifteen  bushels  on 
clays  have  been  applied  :  the  farmers  of 
Western  New- York  look  uponjtwo  bush- 
els per  acre  as  sufficient.  It  is  chiefly 
valuable  to  leguminous  plan's,  as  pease, 
beans,  clover,  saintfoin,  and  lucerne.     It 


should  be  sown  broadcast  in  spring 
when  the  young  leaves  are  started  ;  it 
then  throws  turnips  on  to  grow  so  quick 
that  they  escape  the  ravages  of  the  fly. 
On  account  of  dissolving  so  sparingly  in 
water,  it  is  best  sown  in  wet  weather. 

Calcined  gypsum  after  being  moistened 
with  a  solution  of  alum,  and  again  burn- 
ed, acquires  much  greater  hardness  and 
solidity.  A  Mr.  Kreating  lias  recom- 
mended for  the  same  purpose  a  solution 
of  1  lb  borax  in  9  lbs.  of  water,  which  is 
poured  over  the  calcined  fragments  of 
gypsum.  They  are  then  kept  at  a  strong 
red  heat  for  six  hours,  ground  to  a  pow- 
der, and  worked.  The  effect  is  better  if 
a  lb.  of  tartar  and  twice  the  quantity  of 
water  were  added  to  the  solution. 

HAIR.  The  characteristic  covering  ot 
the  mammiferous  class  of  animals.  It 
consists  of  slender,  more  or  less  elon- 
gated, horny  filaments,  secreted  by  a 
matrix,  consisting  of  a  conical  gland  or 
bulb,  and  a  capsule,  which  is  situated  in 
the  mesh-work  of  the  corium,  or  true 
skin.  The  hairs  pass  out  through  ca- 
nals in  the  corium,  which  are  lined  by  a 
thin  layer  of  cuticle  adherent  to  the  base 
of  the  hair :  the  straightness  or  curl  of 
the  hair  depends  on  the  form  of  the  ca- 
nal through  which  it  passes.  Spines, 
bristles,  fur,  and  wool,  are  all  modifica- 
tions of  hair,  having  the  same  chemical 
composition,  mode  of  formation,  and 
general  structure. 

In  the  spines  of  the  porcupine,  the 
bulb  secretes  a  fluted  pith,  and  the  cap- 
sule invests  it  with  a  horny  sheath,  the 
transparency  of  which  allows  the  ridges 
of  the  central  part  to  be  seen.  In  the 
spines  of  the  hedgehog,  the  spine-like 
whiskers  of  the  walrus,  and  the  bristles 
of  the  hog,  the  twofold  structure  of  the 
hair  is  very  conspicuous  :  but  in  the  finer 
kind  of  hair,  as  in  the  human  head  and 
beard,  the  central  pith  can  only  be  de- 
monstrated in  fine  transverse  sections 
viewed  with  the  microscope.  Some  kinds 
of  hair,  as  of  the  human  head,  the  mane 
and  tail  of  the  horse,  are  perennial,  and 
grow  continuously  by  a  persistent  ac- 
tivity of  the  formative  capsule  and  pulp  ; 
other  kinds,  as  the  ordinary  hair  of  the 
horse,  cow,  and  deer,  are  annual,  and  the 
coat  is  shed  at  particular  seasons.  In  the 
deer  the  horns  are  shed  contempora- 
neously with  the  deciduous  hair. 

Many  quadrupeds,  especially  those^  of 
cold  climates,  have  two  kinds  of  hair : 
a  long  and  coarse  kind,  forming  their 
visible  external  covering ;  and  a  shorter, 
finer,  and  more  abundant  kind,  which 


238 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[hai 


lies  close  to  the  skin,  and  called  "  fur." 
It  is  one  of  the  processes  in  the  arts  to 
remove  the  close  hairs,  and  leave  the  fur 
attached  to  the  dried  skin,  as  in  the  pre- 
paration of  seal-skin,  &c.    The  peculiar 
characteristic  of  wool,  and  that  on  which 
its  valuable  qualities  chiefly  depend,  is 
the  serrated  character  of  its  surface,  aris- 
ing from  its  structure,  which  consists  of 
a  series  or  succession  of  inverted  cones, 
the  base  of  each  being  directed  from  the 
root  of  the  woolly  fibre,  and  receiving 
the  apex  of  the  succeeding  cone.    It  re- 
sults from  this  structure  that  the  pres- 
sure to  which  the  workman  subjects  the 
wool  in  moving  it  backwards  and  for- 
wards  brings  the  fibres    together,  and 
multiplies  their  points  of  contact.    The 
agitation  gives  to  each  hair  a  progressive 
motion  towards  the  root,  and  the  serra- 
tions of  one  hair  fix  themselves  on  those 
of  another  hair  which  happens  to  have 
its  root  turned  in  the  opposite  direction, 
and  the  mass  at   length   assumes    the 
compact  form  which  is  termed  "felted" 
woof.    The  microscope  has  likewise  de- 
monstrated   various    other    remarkable 
modification  in  the  form  of  the  hair  in 
different  quadrupeds.    In  the  mole,  each 
hair  is   alternately  constricted  and  ex- 
panded from  its  root  to  its  apex,  where- 
by it  readily  assumes  any  position,  and 
lies  flat  and  smooth,  either  towards  the 
head  when  the  little  burrower  is  retro- 
grading in  his  subterranean  galleries,  or 
in  the  contrary  direction  when  moving 
forwards.     The  organization  of  the  hair 
is  such  as  to  allow  of  its  undergoing 
certain  changes  when  once  formed,  ac- 
cording to  the  state  of  health  and  gene- 
ral condition  of  the  rest  of  the  frame, 
and  even  to  be  affected  by  loss  of  color 
in  consequence  of  violent  mental  emo- 
tions in  the  human  subject.     Some  of 
the  lower  animals,  as  the  Alpine  hare, 
are  subject  to  periodical  change  of  color 
of  their  fur,    by  which   it  is   made   to 
harmonize  with  the   prevailing  hue  of 
the  ground  which  they  habitually  tra- 
verse. 

The  chemical  properties  of  hair  were 
first  pointed  out  by  Mr.  Hatchett.  It 
chiefly  consists  of  an  indurated  albu- 
men, and  when  boiled  with  water,  it 
yields  a  portion  of  gelatine.  Soft  flexi- 
ble hair,  which  easily  loses  its  curl,  is  that 
which  is  most  gelatinous.  Vauquelin 
discovered  two  kinds  of  oil  in  .hair  :  the 
one  colorless,  and  in  all  hair ;  the  other 
colored,  and  imparting  according  to  its 
color  the  peculiar  tint  of  hair  in  the  indi- 
vidual. 


HAIR  PENCILS  or  BRUSHES  for 
painting.  Two  sorts  are  made;  those 
with  coarse  hair,  as  that  of  the  swine, 
the  wild  boar,  the  dog,  &c,  which  are 
attached  usually  to  short  wooden  rods 
as  handles ;  those  are  commonly  called 
brushes;  and  hair  pencils,  properly  so 
called,  which  are  composed  of  very  fine 
hairs,  as  of  the  minever,  the  marten, 
the  badger,  the  polecat,  &c.  These  are 
mounted  in  a  quill  when  they  are  small 
or  of  moderate  size,  but  when  larger 
than  a  quill,  they  are  mounted  in  white 
iron-tubes. 

The  most  essential  quality  of  a  good 
pencil  is  to  form  a  fine  point,  so  that  all 
the  hairs  without  exception  may  be 
united  when  they  are  moistend  by  laying 
them  upon  the  tongue,  or  drawing  them 
through  the  lips.  When  hairs  present 
the  form  of  an  elongated  cone  in  a  pencil, 
their  point  only  can  be  used.  The  whole 
difficulty  consists  after  the  hairs  are 
cleansed,  in  arranging  them  together  so 
that  all  their  points  may  lie  in  the  same 
horizontal  plane.  We  must  wash  the 
tails  of  the  animals  whose  hairs  are  to  be 
used,  bv  scouring  them  in  a  solution  of 
alum  till  they  be  quite  free  from  grease, 
and  then  steeping  them  for  24  hours  in 
lukewarm  water.  We  next  squeeze  out 
the  water  by  pressing  them  strongly 
from  the  root  to  the  tip,  in  order  to  lay 
the  hairs  as  smooth  as  possible.  They 
are  to  be  dried  with  pressure  in  linen 
cloths,  combed  in  the  longitudinal  direc- 
tion with  a  very  fine-toothed  comb,  final- 
ly wrapped  up  in  fine  linen,  and  dried. 
When  perfectly  dry,  the  hairs  are  seized 
with  pincers,  cut  across  close  to  the  skin, 
and  arranged  in  separate  heaps,  accord- 
ing to  their  respective  lengths. 

Each  of  these  little  heaps  is  placed  se- 
parately, one  after  the  other,  in  small  tin 
pans  with  flat  bottoms,  with  the  tip  of 
the  hair  upwards.  On  striking  the  bot- 
tom of  the  pan  slightly  upon  a  table,  the 
hairs  get  arranged  parallel  to  each  other, 
and  their  delicate  points  rise  more  or  less 
according  to  their  lengths.  The  longer 
ones  are  to  be  picked  out  and  made  into 
so  many  parcels,  whereby  each  parcel 
may  be  composed  of  equally  long  hairs. 
The  perfection  of  the  pencil  depends 
upon  this  equality;  the  tapering  point 
being  produced  simply  by  the  attenua- 
tion of  the  tips. 

A  pinch  or  one  of  these  parcels  is  then 
taken,  of  a  thickness  corresponding  to 
the  intended  size  of  the  pencil ;  it  is  set 
in  a  little  tin  pan,  with  its  tips  undor- 
most,  and  is  shaken  by  striking  the  pan 


har] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


239 


on  the  table  as  before.  The  root  end  of 
the  hairs  being  tied  by  the  fisherman's 
or  seaman's  knot  with  a  fine  thread,  it  is 
taken  out  of  the  pan,  and  then  hooped 
with  stronger  thread  or  twine  ;  the  knot 
being  drawn  very  tight  by  means  of  two 
little  sticks.  The  distance  from  the  tips 
at  which  these  ligatures  are  placed  is  of 
course  relative  to  the  nature  of  the  hair, 
and  the  desired  length  of  the  pencil.  The 
base  of  the  pencil  must  be  trimmed  flat 
with  a  pair  of  scissors. 

Nothing  now  remains  to  be  done  but 
to  mount  the  pencils  in  quill  or  tin-plate 
tubes,  as  above  described.  The  quills 
are  those  of  swans,  geese,  ducks,  lap- 
wings, pigeons,  or  larks,  according  to 
the  size  ol  the  pencil.  They  are  steeped 
during  24  hours  in  water,  to  swell  and 
soften  them,  and  to  prevent  the  chance 
of  their  splitting  when  the  hair-brush  is 
pressed  into  them.  The  brush  of  hair  is 
introduced  by  its  tips  into  the  larger  end 
of  the  cut  quill,  having  previously  drawn 
them  to  a  point  with  the  lips,  when  it  is 

Sushed  forwards  with  a  wire  of  the  same 
iameter,  till  it  comes  out  at  the  other 
and  narrower  end  of  the  quill. 

HANDSPIKE.  A  wooden  lever  used 
on  shipboard  for  working  the  windlass 
and  capstan,  one  end  of  which  is  squared 
to  fit  the  holes  of  the  capstan-head  and 
in  the  barrel  of  the  windlass. 

HANK,  in  spinning,  the  name  given 
to  two  or  more  skeins  of  yarn,  silk,  or 
cotton,  when  tied  together. 

HAKBOE,  has  been  defined  to  be  a 
piece  of  water  communicating  with  the 
sea,  or  with  a  navigable  river  or  lake, 
having  depth  sufficient  to  floats  ships  of 
considerable  burden,  where  there  is  con- 
venient anchorage,  and  where  ships  may 
lie,  load,  and  unload,  screened  from  the 
winds  and  beyond  the  reach  of  the  tide. 

HAED  BODIES,  in  Natural  Philoso- 
phy, are  such  as  resist  any  pressure  or 
percussion  whatever,  in  opposition  to  soft 
bodies,  the  parts  of  which  readily  yield 
to  pressure,  and  do  not  recover  them- 
selves ;  and  to  elastic  bodies,  the  parts 
of  which  also  yield  to  pressure  or  impact, 
but  presently  recover  themselves  when 
the  disturbing  force  ceases  to  act. 

HARDNESS.  In  physics,  that  quality 
of  bodies  in  virtue  of  which  their  parti- 
cles resist  the  action  of  any  external  force 
tending  to  alter  their  relative  positions, 
or  to  impart  to  them  any  motion  in  re- 
spect of  each  other.  Newton  supposes 
the  primary  particles  of  all  bodies  to  be 
perfectly  hard,  and  not  capable  of  being 
broken  or  divided  by  any  power  in  na- 


ture ;  but  we  are  still  too  little  acquaint- 
ed with  the  constitution  of  matter  to  de- 
termine with  any  certainty  the  conditions 
of  the  elementary  particles  which  render 
bodies  hard,  brittle,  and  elastic. 

Hardness.  In  Mineralogy.  Minerals 
may  occasionally  be  distinguished  and 
identified  by  their  relative  degrees  of 
hardness  ;  to  specify  which  various  scales 
have  been  suggested,  among  which  that 
of  Mohs  is  perhaps  the  most  simple. 
According  to  it  the  relative  degrees  of 
hardness  are  expressed  in  numbers,  re- 
ferring to  the  following  standard  sub- 
stances, which  are  easily  obtained  in  a 
state  of  purity,  or  crystallized  ;  namely, 

1.  Talc.  6.  Adularia  (Feldspar). 

2.  Rook-salt.  7.  Rock-crystai. 

3.  Calc-spar.  8.  Topaz. 

4.  Fluor-spar.  9.  Corundum. 

5.  Apatite.  10.  Diamond. 

Any  mineral,  which  neither  scratches 
nor  is  scratched  by  any  one  of  the  above 
substances,  is  said  to  possess  the  hardness 
expressed  by  the  attached  number.  Thus 
if  a  mineral  neither  scratches  nor  is 
scratched  by  calcareous  spar,  its  hardness 
is  represented  by  3  ;  if  it  scratches  feld- 
spar and  not  rocK-crystal,  its  hardness  is 
stated  to  be  between  6  and  7. 

HABDW  ABE,  is  used  to  signify  every 
kind  of  goods  manufactured  from  metals, 
comprising  iron,  brass,  steel,  and  copper 
articles  of  all  descriptions.  The  hard- 
ware manufacture  is  one  of  the  most  im- 
portant carried  on  in  Great  Britain.  Its 
Erincipal  seats  are  Birmingham  and  Shef- 
eld,  which  furnish  immense  quantities 
of  knives,  razors,  scissors,  gilt  and  plated 
ware,  fire-arms,  &c,  both  for  home  con- 
sumption and  exportation. 

HAEEOW.  In  agriculture,  a  rectan- 
gular frame  with  a  number  of  spikes  in- 
serted in  it  on  one  side.  This  frame 
when  dragged  over  ploughed  land,  breaks; 
the  furrow  slices  into  small  pieces,  for  the 
purpose  of  preparing  the  land  for  seed  in 
some  cases,  and  for  covering  the  seed  in 
others.  The  most  common' form  of  the 
frame  of  the  harrow  is  rectangular,  and 
the  usual  material  employed  is  wood, 
with  the  spikes  of  iron ;  but  in  some 
cases  both  the  frame  and  the  spikes  are 
of  wood,  and  in  others  both  are  of  iron. 
Occasionally  the  frame  is  a  circle  of  iron, 
and  the  spikes  are  inserted  in  it,  at  such 
distances  that  when  the  frame  is  drawn 
along  in  a  straight  line,  the  spikes,  or 
tines  as  they  are  technically  termed,  pass 
through  every  part  of  the  soil  traversed 
by  the  frame  "or  harrow.  In  the  common 
kinds  of  harrows  the  spikes  are  inserted 


240 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


I? 


at  right  angles  to  the  frame  :  but  in  the 
improved  forms  they  are  inserted  at  an 
oblique  angle,  or  pointing  forwards,  by 
which  means  the  harrow  is  drawn  much 
more  easily  through  the  soil.  The  best 
implement  of  this  description  at  present 
in  use  is  Finlayson's  harrow.    This  im- 

Element,  by  means  of  a  long  lever,  can 
e  regulated  to  such  a  nicety  as  to  stir 
the  soil  to  the  depth  of  only  one  or  two 
inches,  for  the  purpose  of  covering  grass 
or  clover  seeds  ;  or  it  can  be  pressed  into 
it  of  such  a  depth  as  to  serve,  in  the  case 
of  stubble  lands,  instead  of  ploughing. 
Wilkie's  harrow  and  Kirkwood's  harrow 
can  be  used  for  similar  purposes.  They 
differ  nothing  from  Finlayson's  in  prin- 
ciple ;  but  being  on  a  smaller  scale  can  be 
worked  with  fewer  horses  than  Finlay- 
son's, which  commonly  requires  four  or 
six. 

HARROWING.  The  process  of  draw- 
ing a  harrow  through  the  soil  for  the  pur- 
pose of  reducing  it  to  a  level,  of  covering 
seed,  or  of  turning  up  weeds  in  ploughed 
ground,  or  moss  in  grass  lands.  In  agri- 
culture the  harrow  is  drawn  by  horses  or 
oxen ;  and  in  market-gardening,  where  a 
light  harrow  is  sometimes  employed,  by 
men.  In  either  case  the  more  rapid  the 
motion  of  the  harrow,  up  to  a  certain 
point,  the  more  efficient  will  be  its  opera- 
tion. For  meadow  lands,  the  object  of 
harrowing  is  to  disperse  the  little  heaps 
of  earth  raised  during  winter  and  early 
spring  by  moles  and  worms ;  and  for 
this  purpose  the  harrows  in  some  parts 
of  the  country  are  turned  upside  down ; 
while  in  others,  less  advanced,  thorn 
branches  are  tucked  into  a  frame  resem- 
bling a  harrow,  and  dragged  over  the 
surface  for  the  purpose  of  effecting  the 
same  object.  This  is  called  a  bush  har- 
row. 

HARTSHORN,  SPIRIT  OF.  An  im- 
pure solution  of  carbonate  of  ammonia, 
obtained  by  the  destructive  distillation 
of  hartshorn  or  any  kind  of  bone.  It  is 
now  never  made  by  this  process,  but  by 
a  direct  solution  of  the  pure  carbonate  of 
ammonia. 

HAT  MANUFACTURE.  The  mate- 
rials used  for  making  hats  are,  besides  silk, 
the  fur  of  hares  and  rabbits  chosen  from 
the  long  hair  ;  together  with  wool  and 
beaver  and  nutria.  The  two  latter  are 
reserved  for  the  finer  hats.  The  body  of 
a  beaver  hat  is  made  of  fine  wool  and 
coarse  fur  mixed  and  felted  together, 
then  stiffened  and  shaped  ;  the  covering 
consists  of  a  coat  of  beaver-fur  felted 
upon  the  body.    Cheap  hats  have  their 


bodies  made  of  coarse  wool,  and  their  co- 
verings of  coarse  fur  or  fine  wool.  The 
body'br  foundation  of  a  good  beaver  hat, 
is  at  present  made  of  8  parts  of  rabbit's 
fur,  3  parts  of  Saxony  wool,  and  1  part  of 
lama,  vicunia,  or  red  wool.  About  two 
ounces  and  a  half  of  the  above  mixture 
are  sufficient  for  one  hat,  and  these  are 
placed  in  the  hands  of  the  bower  ;  his 
tool  is  a  bow  or  bent  ashen  staff,  from  5 
to  7  feet  long,  having  a  strong  catgut 
string  stretched  over  a  bridge  at  each  end, 
and  suspended  at  its  middle  by  a  cord  to 
the  ceiling,  so  as  to  hang  nearly  level  with 
the  work  bench,  and  a  small  space  above 
it.  The  wool  and  coarser  fur  are  laid  in 
their  somewhat  matted  state  upon  this 
bench,  when  the  bower,  grasping  the  bent 
rod  with  his  left  hand,  and  oy  means  of  a 
small  wooden  catch  plucking  the  string  with 
his  right,  makes  it  vibrate  smartly  against 
the  fibrous  substances,  so  as  to  disentan- 
gle them,  toss  them  up  in  the  air,  and 
curiously  arrange  themselves  in  a  pretty 
uniform  layer  or  fleece.  A  skilful  bower 
is  a  valuable  workman.  The  bowed  ma- 
terials of  one  hat  are  spread  out  and  di- 
vided into  two  portions,  each  of  which  is 
compressed,  first  with  a  light  wicker 
frame,  and  next  under  a  piece  of  oil  cloth 
or  leather,  called  a  hardening  skin,  till  by 
pressing  the  hands  backward  and  for- 
ward all  over  the  skin,  the  filaments  are 
linked  together  by  their  serrations  into  a 
somewhat  coherent  fleece  of  a  triangular 
shape.  The  two  halves  or  "  bats  "  are 
then  formed  into  a  cap ;  one  of  them  is 
covered  in  its  middle  with  a  8-eornered 
piece  of  paper,  smaller  than  itself,  so  that 
its  edges  may  be  folded  over  the  paper, 
and  by  overlapping  each  other  a  little, 
form  a  complete  envelope  to  the  paper ; 
the  junctions  are  then  partially  felted  to- 
gether by  rubbing  them  hard,  care  being 
taken  to*  keep  the  base  of  the  triangle 
open  by  means  of  the  paper ;  the  second 
bat  being  made  to  enclose  the  first  by  a 
similar  process  of  folding  and  friction. 
This  double  cap,  with  its  enclosed  sheet 
of  paper,  is  next  rolled  up  in  a  damp 
cloth  and  kneaded  with  the  hands  in 
"  every  direction,  during  which  it  is  un- 
folded and  creased  up  again  in  different 
forms,  whereby  the  two  layers  get  tho- 
roughly incorporated  into  one  body ; 
thus,  on  withdrawing  the  paper,  a  hollow 
cone  is  obtained.  This  cap  is  next  taken 
and  dipped  occasionally  into  a  weak  acid 
solution  made  of  vitriol  and  water  and  is 
j  also  wrought  by  hands  or  with  the  roller 
!  on  the  sloping  planks.  This  constitutes 
j  falling  or  thickening  and  is  continued  4 


iiatJ 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


241 


or  5  hours ;  knots  are  picked  out  and 
fresh  felt  added  by  a  wet  brush.  The 
beaver  is  applied  at  the  end  of  this  ope- 
ration on  oeaver  hats.  The  foundation 
of  men's  hats,  upon  the  outside  of  which 
the  beaver,  down,  or  other  fine  fur  is 
laid,  to  produce  a  nap,  is  usually  made 
of  wool  felted  together  by  hand  and  form- 
ed first,  into  conical  caps,  which  are  af- 
terwards stretched  and  moulded  to  the 
desired  shape.  Hemp  and  felt  are  also 
used  as  foundations. 

Stopping,  or  thickening  the  thin  spots, 
seen  by  looking  through  the  body,  is  per- 
formed by  daubing  on  additional  stuff 
with  successive  applications  of  the  hot 
acidulous  liquor  from  a  brush  dipped  into 
the  kettle,  until  the  body  be  sufficiently 
shrunk  and  made  uniform.  After  dry- 
ing, it  is  stiffened  with  varnish  composi- 
tion rubbed  in  with  a  brush  ;  the  inside 
surface  being  more  copiously  imbued 
with  it  than  the  outer  ;  while  the  brim  is 
peculiarly  charged  with  the  stiffening. 

When  once  more  dried,  the  body  is 
ready  to  be  covered,  which  is  done  at  the 
battery.  The  first  cover  of  beaver  or  nap- 
ping, which  has  been  previously  lowed, 
is  strewed  equally  over  the  body,  and 
patted  on  with  a  brush  moistened  with 
the  hot  liquor,  until  it  gets  incorporated ; 
the  cut  ends  towards  the  root,  being  the 
points  which  spontaneously  intrude. 
The  body  is  now  put  into  a  coarse  hair 
cloth,  then  dipped  and  rolled  in  the  hot 
liquor,  until  the  root  ends  of  the  beaver 
are  thoroughly  worked  in.  This  is  tech- 
nically called  rolling  off,  or  roughing.  A 
strip  for  the  brim,  round  the  edge  of  the 
inside,  is  treated  in  the  same  way ;  where- 
by every  thing  is  ready  for  the  second 
cover  (of  beaver),  which  is  incorporated 
in  like  manner;  the  rolling,  &c,  being 
continued,  till  a  uniform,  close,  and  well- 
felted  hood  is  formed. 

The  hat  is  now  ready  to  receive  its  pro- 
per shape.  For  this  purpose  the  work- 
man turns  up  the  edge  or  brim  to  the 
depth  of  about  \\  inch,  and  then  returns 
the  point  of  the  cone  back  again  through 
the  axis  of  the  cap,  so  as  to  produce  ano- 
ther inner  fold  of  the  same  depth.  A 
third  fold  is  produced  by  returning  the 
point  of  the  cone,  and  so  on  till  the  point 
resembles  a  flat  circular  piece  having  a 
number  of  concentric  folds.  In  this  state 
it  is  laid  upon  the  plank,  and  wetted  with 
the  liquor.    The  workman  pulls  out  the 

Joint  with  his  fingers,    and   presses  it 
own  with  his  hand,  turning   it  at  the 
same  time  round  on  its  centre  upon  the 
plank,  till  a  fiat  portion,   equal  to  the 
11 


crown  of  the  hat,  is  rubbed  out.  This  flat 
crown  is  now  placed  upon  a  block,  and, 
by  pressing  a  .string  called  a  commander, 
down  the  sides  of  the  block,  he  forces  the 
parts  adjacent  to  the  crown,  to  assume  a 
cylindrical  figure.  The  brim  now  appears 
like  a  puckered  appendage  round  the  cy- 
lindrical cone  ;  but  the  proper  figure  is 
next  given  to  it,  by  working  and  rubbing 
it.  The  body  is  rendered  waterproof  and 
stiff  by  being  imbued  with  a  varnish 
composed  of  shellac,  sandarach,  mastic, 
and  other  resins  dissolved  in  alcohol  or 
naptha. 

The  hat  being  dried,  its  nap  is  raised  or 
loosened  with  a  wire  brush  or  card,  and 
sometimes  it  is  previously  pounced  or 
rubbed  with  pumice,  to  take  off  the 
coarser  parts,  and  afterwards  rubbed 
over  with  seal-skin.  The  hat  is  now  tied 
with  pack-thread  upon  its  block,  and  is 
afterwards  dyed.    See  Hat-dyeing. 

The  dyed  hats  are  now  removed  to  the 
stiffening  shop.  Beer  grounds  are  next 
applied  on  the  inside  of  the  crown,  for 
the  purpose  of  preventing  the  glue  from 
coming  througli ;  and  when  the  beer 
grounds  are  dried,  glue  (gum  Senegal  is 
sometimes  used)  a  little  thinner  than  that 
used  by  carpenters,  is  laid  with  a  brush 
on  the  inside  of  the  crown,  and  the  lower 
surface  of  the  brim. 

The  hat  is  then  softened  by  exposure 
to  steam,  on  the  steaming  basin,  and  is 
brushed  and  ironed  till  it  receives  the 
proper  gloss.  It  is  lastly  cut  round  at 
the  brim  by  a  knife  fixed  at  the  end  of  a 
gauge,  which  rests  against  the  crown. 
The  brim,  however,  is  not  cut  entirely 
through,  but  is  torn  off  so  as  to  leave  au 
edging  of  beaver  round  the  external  rim 
of  the  hat.  The  crown  being  tied  up  in 
a  gauze  paper,  which  is  neatly  ironed 
down,  is  then  ready  for  the  last  opera- 
tions of  lining  and  binding. 

The  furs  and  wools  of  which  hats  are 
manufactured  contain,  in  their  early  stage 
of  preparation,  hemps  and  hairs,  which 
must  be  removed  in  order  to  produce  a 
material  for  the  better  description  of  hats. 
This  separation  is  effected  by  a  sort  of 
winnowing  machine,  which  wafts  away 
the  finer  and  lighter  parts  of  the  furs  and 
wools  from  the  coarser. 

Silk  hats,  for  several  years  after  they 
were  manufactured,  were  liable  to  two 
objections ;  first,  the  body  or  shell  over 
which  the  silk  covering  is  laid,  was,  from 
its  hardness,  apt  to  hurt  the  head  ;  se- 
cond, the  edge  of  the  crown  being  much 
exposed  to  blows,  the  silk  nap  soon  got 
abraded,  so  as  to  lay  bare  the  cotton  foun- 


242 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hea 


dation,  which  is  not  capable  of  taking  so 
fine  a  black  dye  as  the  silk  ;  whence  the 
hat    assumed*     a     shabby     appearance,  j 
Messrs.  Mayhew  and  White,  of  London, 
hat-manufacturers,   remedied  these  de-  j 
fects,  by  making  the  hat  body  of  stuff  or  | 
wool,  and  relieving  the  stiffness  of  the  in-  j 
ner  part  round  the  brim,  by  attaching  a  ' 
coating  of  beaver  upon  the  under  side  of  j 
the  brim,  so  as  to  render  the  hat  pliable. 
Eound  the  edge  of  the  tip  or  crown,  a  j 
quantity  of  what  is  called  stop  wool  is  to  ' 
be  attached  by  the  ordinary  operation  of 
bowing,  which  will  render  the  edge  soft 
and  elastic.    The  hat  is  to  be  afterwards 
dyed  of  a  good  black  color,  both  outside 
and  inside ;   and  being   then    properly 
stiffened  and  blocked,  is  ready  for  the  co- 
vering of  silk. 

The  plush  employed  for  covering  silk 
hats,  is  a  raised  nap  or  pile  woven  usu- 
ally upon  a  cotton  foundation ;  and  the 
cotton,  being  incapable  of  receiving  the 
same  brilliant  black  dye  as  the  silk,  ren- 
ders the  hat  apt  to  turn  brown  whenever 
the  silk  nap  is  partially  worn  off.  The 
way  to  counteract  this  evil  is  by  making 
the  foundation  of  the  plush  entirely  of 
silk.  To  these  two  improvements,  now 
pretty  generally  introduced,  the  present 
excellence  of  the  silk  hats  may  be,  in  a 
good  measure,  ascribed. 

In  a  great  hat  factory  women  are  em- 
ployed, at  respectable  wages,  in  plucking 
the  beaver  skins,  cropping  off  the  fur, 
sorting  various  qualities  of  wool,  pluck- 
ing and  cutting  rabbit's  fur,  shearing  the 
nap  of  the  blocked  hat,  picking  out  un- 
seemly filaments  of  fur,  and  in  trimming 
the  hats;  that  is,  lining  and  binding 
them. 

With  regard  to  the  stiffening  of  hats, 
Dr.  Ure  gives  the  following  receipts 
as  furnished  by  a  skilful  operator  with 
the  following  valuable  information : — 
All  the  solutions  of  gums  which  I  have 
hitherto  seen  prepared  by  hatters,  have 
not  been  perfect,  out,  in  a  certain  degree, 
a  mixture,  more  or  less,  of  the  gums, 
which  are  merely  suspended,  owing  to 
the  consistency  of  the  composition. 
When  this  is  thinned  by  the  addition  of 
spirit,  and  allowed  to  stand,  it  lets  fall  a 
curdy  looking  sediment,  and  to  this  cir- 
cumstance may  be  ascribed  the  frequent 
breaking  of  hats.  My  method  of  pro- 
ceeding is,  first,  to  dissolve  the  gums  by 
agitation  in  twice  the  due  quantity  of 
spirits,  whether  of  wood  or  wine,  and 
then,  after  complete  solution,  draw  off 
one  half  the  spirits  in  a  still,  so  as  to 
bring  the  stiffening  to  a  proper  consisten- 


cy. No  sediment  subsequently  appears 
on  diluting  this  solution,  however  much 
it  may  be  done. 

Both  the  spirit  and  alkali  stiffenings 
for  hats  made  by  the  following  two  re- 
ceipts, have  been  tried  by  some  of  the 
first  houses  in  the  trade,  and  have  been 
much  approved  of: — 

Spirit  Stiffening, 
7  pounds  of  fine  orange  shellac. 
2  pounds  of  gum  sandarac. 
4  ounces  of  gum  mastic. 
Half  a  pound  of  amber  resin. 
1  pint  of  solution  of  copal. 
1  gallon  of  spirit  of  wine  or  wood  naptha. 

The  shellac,  sandarac,  mastic,  and  re- 
sin, are  dissolved  in  the  spirit,  and  tho 
solution  of  copal  is  added  last. 

Alkali  Stiffening. 
7  pounds  of  common  black  shellac 
1  pound  of  amber  resin. 
4  ounces  of  gum  rhus. 
6  ounces  of  borax. 
Half  a  pint  of  solution  of  copal. 

Hat-dyking.  The  ordinary  bath  for 
dyeinsf  hats,  employed  by  the  London 
manufacturers,  consists,  for  12  dozen, 
of— 

144  pounds  of  logwood. 
12  pounds  of  green  sulphate  of  iron,  or  cop- 
peras. 
1)4  pounds  of  verdigris. 

The  copper  is  usually  made  of  a  semi- 
cylindrical  shape,  and  should  be  sur- 
rounded with  an  iron  jacket  or  case,  into 
which  steam  may  be  admitted,  so  as  to 
raise  the  temperature  of  the  interior  bath 
to  190°  F.,  but  no  higher,  otherwise  the 
heat  is  apt  to  affect  the  stiffening  varnish, 
called  the  gum,  with  which  the  body  of 
the  hat  has  been  imbued.  The  logwood 
having  been  introduced  and  digested  for 
some  time,  the  copperas  and  verdigris  are 
added  in  successive  quantities,  and  in  the 
above  proportions,  along  with  every  suc- 
cessive two  *r  three  dozens  of  hats,  sus- 
pended upon  the  dipping  machine.  Each 
set  of  hats,  after  being  exposed  to  the 
bath  with  occasional  airings  during  40 
minutes,  is  taken  off  the  pegs,  and  laid 
out  upon  the  ground  to  be  more  com- 
pletely blackened  by  the  peroxydizement 
of  the  iron  with  the  atmospheric  oxvgen. 
In  3  or  4  hours  the  dyeing  is  completed. 
When  fully  dyed,  the  hats  are  well  wash- 
ed in  ranning  water. 

HEART  WHEEL.  The  name  given  to 
a  well-known  mechanical  contrivance  for 
converting  a  circular  motion  into  an  al- 
ternating rectilinear  one,  common  in  cot- 
ton mills.    It  is  an  ellipse  turned  either 


hem] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


on  an  axle,  or  by  means  of  a  winch  and 
handle  on  one  of  its  foci,  or  its  centre,  on 
whose  edge  a  movable  point  or  circle 
presses  ;  the  latter  receives  an  alternating 
motion  from  the  circumference  of  the  el- 
lipse, which  in  its  revolution  presses  it 
to  different  distances  from  the  centre  of 
motion.  The  practical  disadvantages  of 
this  contrivance  are  the  inequality  of 
pressure  and  of  moving  force  which  will 
be  required  at  different  parts  of  the  rota- 
tion of  the  ellipse,  and  the  consequent 
wearing  of  some  parts  of  it  faster  than 
others. 

HEAVY  SPAR.  Native  sulphate  of 
baryta.  This  is  a  common  mineral  in 
many  raining  districts.  It  occurs  in 
several  crystalline  forms,  of  which  the 
cleavage  is  a  right  rhomboidal  prism ;  it 
also  occurs  fibrous,  radiated,  and  stalac- 
titic.  Some  beautiful  specimens  of  the 
latter  variety  have  been  found  in  Derby- 
shire of  a  brown  color.  The  crystals  are 
usually  white,  or  nearly  colorless.  The 
specific  gravity  of  sulphate  of  baryta  is 
4*1  to  4-6.  It  consists  of  77  baryta,  40  sul- 
phuric acid,  its  equivalent  being  117.  It 
enters  into  the  composition  of  some  kinds 
of  pottery,  but  its  chief  consumption  is 
in  the  adulteration  of  white  lead.  It  is  a 
mineral  common  in  the  States  of  New- 
York  and  New  Jersey. 

HECKLE  is  an  implement  for  dissev- 
ering the  filaments  of  flax,  and  laying 
them  in  parallel  stricks  or  tresses.  See 
Flax. 

HELIOCHROMATYPE.  Under  the 
article  Daguerreotype,  notice  has  been 
taken  of  the  attempts  of  Becquerel  and 
Hill,  to  produce  naturally  colored  impres- 
sions on  the  silver  plate.  In  March  of 
this  year  (1851),  M.  Niepce  de  St.  Victor 
communicated  to  the  Paris  Academy  of 
Sciences,  a  memoir  showing  the  manner 
of  taking  the  natural  colors.  Having 
formed  the  idea  that  there  might  be  some 
relation  between  the  color  that  a  sub- 
stance communicates  to  flame,  and  the 
color  that  light  produces  on  a  plate  of 
silver  chloridized  with  the  substance  that 
colors  the  flame,  he  undertook  the  expe- 
riments which  led  to  his  success.  He 
found  it  necessary  to  expose  the  plate  to 
chlorine,  and  then  coat  it  with  the  chlo- 
ride of  the  particular  metal  he  was  inves- 
tigating; no  other  salts  acted  similarly 
to  the  chlorides.  Dry  chlorine  does  not 
produce  any  effect,  but  when  the  plate  is 
immersed  in  the  liquid  chlorine,  or  ex- 
posed to  the  aqueous  vapor,  the  colors 
are  all  reproduced.  The  mode  of  operat- 
ing is  thus  :    The  bath  is  made  of  chlo-  j 


en 


rine  1  part,  and  3  parts  of  water.  When 
hydrochloric  acid,  with  a  salt  of  copper, 
is  used,  it  is  diluted  with  1-10  of  water. 
The  liquid  chlorine  should  not  be  con- 
centrated, as  good  yellows  are  not  then 
obtained.  Clear  solutions  and  stoppered 
bottles  should  be  used.  The  purest  sil- 
ver plate  is  preferable  for  these  experi- 
ments j  this  is  cleaned  with  ammonia 
and  tnpoli,  then  plunged  into  the  bath, 
and  left  there  for  some  minutes  in  order 
to  receive  a  sufficiently  heavy  coating, 
the  plate  is  then  removed,  rinsed  with 
water,  and  dried  by  a  spirit-lamp.  In 
the  bath  it  takes  on  a  dark  color,  almost 
black,  and  though  it  will  take  the  colors. 
yet  the  ground  will  be  black.  In  order 
to  have  a  cleai'er  ground  and  a  quicker 
operation,  the  plate  is  changed  by  heat 
to  a  cherry  red,  when  the  dark  plate 
is  heated  by  a  lamp  placed  below  it.     It 

asses    through     the    following    tints, 

ownish  red,  cherry  red,  bright  red, 
reddish  white,  whitish.  In  the  last 
stage  it  has  lost  the  power  of  producing 
images.  The  plate  should  only  be 
brought  to  the  cherry  red  condition.  It 
is  then  to  be  exposed  in  the  camera.  To 
obtain  a  picture  it  requires  two  hours. 
This  must  be  owing  to  Niepce's  not  using 
any  accelerator ;  he  mentions  fluoride 
of  soda,  chl6ric  acid,  and  the  chlorates  as 
worthy  of  trial  for  this  purpose.  These 
images  disappear  very  quickly,  and 
Niepce  has  not  been  successful  in  fixing 
them  ;  exposing  the  plate  to  the  flame  of 
alcohol  containing  chloride  of  sodium  or 
muriate  of  ammonia,  partially  succeeds. 
The  chlorides  which,  when  employed 
alone,  act  upon  the  silver  plate,  so  as  to 
make  it  take  all  the  several  colors  of  the 
model,  arc  the  chlorides  of  copper,  of 
iron,  of  nickel,  uf  potassium,  and  the  hy- 
pochlorites of  soda  and  lime,  as  well  as 
liquid  chlorine. 

It  is  evident  from  the  foregoing,  that 
Heliochromatype  is  yet  but  in  its  infancy, 
and  cannot  be  practically  applied  as  yet. 

HELIOTROPE  is  a  variety  of  jasper, 
mixed  with  chlorite,  green  earth,  and 
diallage ;  occasionally  marked  with  blood- 
red  points ;  whence  its  vulgar  name  of 
blood-stone. 

HEMATINE  is  the  name  given  by  its 
discoverer,  Chevreul,  to  a  crystalline  sub- 
stance, of  a  pale  pink  color,  and  brilliant 
lustre  when  viewed  in  a  lens,  which  he 
extracted  from  logwood,  the  hcematoxylon 
Canvpeehiawum  of  botanists.  It  is,  in  fact, 
the  characteristic  principle  of  this  dye- 
wood.  To  procure  hematine,  digest,  dur- 
ing a  few  hours,   ground    logwood    in 


244 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hem 


■water  heated  to  a  temperature  of  about 
130°  F. ;  filter  the  liquor,  evaporate  it  to 
dryness  by  a  steam  bath,  and  put  the  ex- 
tract in  alcohol  of  0-835  for  a  day.  Then 
filter  anew,  and  after  having  inspissated 
the  alcohol  solution  by  evaporation,  pour 
it  into  a  little  water,  evaporate  gently 
again,  and  then  leave  it  to  itself  in  a  cool 
place.  In  this  way  a  considerable  quan- 
tity of  crystals  of  hematine  will  be  ob- 
tained, which  may  be  readily  purified  by 
washing  with  alcohol  and  drying. 

When  subjected  to  dry  distillation  in 
a  retort,  hematine  affords  all  the  usual 
products  of  vegetable  bodies,  along  with 
a  little  ammonia :  which  proves  the  pre- 
sence of  azote.  Boiling  water  dissolves 
it  abundantly,  and  assumes  an  orange- 
red  color,  which  passes  into  yellow  by 
cooling,  but  becomes  red  again  with  heat. 
Sulphurous  acid  destroys  the  color  of 
solution  of  hematine.  Potash  and  am- 
monia convert  into  a  dark  purple-red  tint, 
the  pale  solution  of  hematine ;  when  these 
alkalis  are  added  in  large  quantity,  they 
make  the  color  violet  blue,  then  brown- 
red,  and  lastly  brown-yellow.  By  this 
time,  the  hematine  has  become  decom- 
posed, and  cannot  be  restored  to  its  pris- 
tine state  by  neutralizing  the  alkalies  with 
acids. 

The  waters  of  baryta,  strontia,  and  lime 
exercise  an  analogous  power  of  decompo- 
sition ;  but  they  eventually  precipitate 
the  changed  coloring  matter. 

A  red  solution  of  hematine  subjected 
to  a  current  of  sulphureted  hydrogen  be- 
comes yellow ;  but  it  resumes  its  original 
hue  when  the  sulphureted  hydrogen  is 
removed  by  a  little  potash. 

The  protoxyde  of  lead,  the  protoxyde 
of  tin,  the  hydrate  of  peroxyde  of  iron, 
the  hydrate  "of  oxydes  of  "copper  and 
nickel,  oxyde  of  bismuth,  combine  with 
hematine,  and  color  it  blue  with  more 
or  less  of  a  violet  cast. 

Hematine  precipitates  glue  from  its  so- 
lution in  reddish  flocks.  This  substance 
has  not  hitherto  been  employed  in  its 
pure  state ;  but  as  it  constitutes  the  ac- 
tive principle  of  logwood,  it  enters  as  an 
ingredient  into  all  the  colors  made  with 
that  dye-stuff. 

These  colors  are  principally  violet  and 
black.  Chevreul  has  proposed  hematine 
as  an  excellent  test  of  acidity. 

HEMATITE  is  a  native  reddish-brown 
peroxyde  of  iron,  consisting  of  oxygen 
80-66  ;  iron  60-34.  It  is  the  kidney  ore  of 
Cumberland,  which  is  smelted  at  Ulver- 
stono  with  charcoal,  into  excellent  steel 
iron.    It  is  one  of  the  most  abundant  and 


valuable  of  the  iron  ores  in  the  United 
States.    See  Ikon. 

HEMP.  The  fibres  of  the  cannabis 
sativa ;  a  plant  grown  extensively  in  this 
country,  but  mostly  in  Kentucky  and 
Missouri.  It  is  a  native  of  India  and 
Persia,  and  was  thence  introduced  into 
Europe.  Though  much  grown  here,  yet 
more  is  imported  from  Russia.  It  grows 
wild  in  many  waste  places.  It  grows 
well  on  strong  soils,  and  hence  on  newly 
cleared  lands.  Soon  after  flowering,  the 
male  plants  are  pulled,  and  the  female 
plants  let  to  remain  some  weeks  longer  to 
mature  the  seed.  These  do  not  preserve 
their  vitality  longer  than  a  year,  owingr  to 
the  large  quantity  of  oil  in  them.  The 
males  should  be  tied  immediately  in  bun- 
dles, the  roots  cut  off  while  fresh,  the 
upper  leaves  also  beaten  off,  and  it  is  the 
most  eligible  practice  to  immerse  them 
in  water  without  delaying  for  rotting. 
The  females,  which  are  three  times  more 
numerous  than  males,  should  be  pulled 
very  carefully,  without  shaking  or  inclin- 
ing the  summits,  and  the  flail  should  not 
be  used,  as  it  bruises  the  seed.  This, 
when  separated,  should  be  spread  out 
and  turned  at  intervals,  and  exposed  to  a 
current  of  air;  otherwise  they  ferment. 
The  process  of  rotting  consists  in  the 
decomposition  of  the  substance  which 
envelopes  and  unites  the  fibres,  and  takes 
place  much  more  rapidly  in    stagnant 

f)Ools  than  in  running  water  or  extensive 
akes,  in  warm  weather  than  the  re- 
verse. The  time  requisite  varies  from 
five  to  fifteen  days,  even  in  stagnant 
water.  The  water  in  which  hemp  has 
been  rotted  has  a  disagreeable  odor  and 
taste,  proving  fatal  to  fishes,  and  should 
be  distant  from  any  inhabited  place,  lest 
it  engender  pestilential  diseases.  When 
water  is  not  at  hand,  hemp  is  rotted  in 
the  open  air,  by  spreading  it  at  night 
upon  the  green-sward,  and  heaping  it 
together  in  the  morning,  before  the  sun's 
rays  have  much  power.  In  wet  weather 
it  may  be  left  on  the  ground  during  the 
whole  day  ;  and  should,  the  nights  be  very 
dry,  it  is'better  to  water  it.  This  process 
is  called  dew-rotting,  and  is  very  tedious, 
requiring  three,  six,  or  even  eight  weeks. 
Another  method  again,  is  by  placing  it 
in  a  pit,  and  covering  it  over*  with  about 
one  foot  of  earth,  after  having  watered  it 
abundantly  a  single  time ;  but  even  this 
method  requires  double  the  time  of 
water.  After  being  rotted  and  rapidly 
dried,  it  is  ready  for  canting,  beating, 
&c,  but  these  subsequent  manipulations 
are  found  by  experience  to  be  very  un- 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


245 


healthy,   probably  from    the   fine  dust 
created  and  flying  about. 

J.  T.  Crook  &  Co.,  Maysville,  Ohio, 
have  sent  into  the  markets  cordage  manu- 
factured by  them,  of  rotted  hemp,  so  ky- 
anized  by  the  use  of  antiseptic  substances 
as  to  render  it  indestructible  when  ex- 
posed to  the  weather.     Cordage,  pre- 
pared like  this,  has  been  buried  in  a  fun- 
gous heap,  filled  with  decaying  vegetable 
matter,  tor  five  years,  without  showing  j 
the  least  sign  of  decay.      In  respect  to  j 
the  preparing  of  this  cordage  in  this  coun-  j 
try,  they  were  compelled  to  use  the  un-  \ 
rotted  hemp,  since  it  is  an  established  fact  ! 
that  antiseptics  will  not  prevent  the  de-  j 
cay  of  vegetable  matter,  when  decay  has  \ 
actually  commenced,  as  is  the  case  of  dew  ; 
and    water-rotted    hemp.       The  Russia 
hemp,  in  not  being  carried  to  the  fer- 
menting point  in  rotting,  is  not,  like  our 
water-rotted  hemp,  affected  by  decay,  and 
is  capable  of  being  kyanized  like  the  un- 
rotted  hemp,  as  has  been   successfully 
done  in  England,  by  the  use  of  suitable 
antiseptics. 

The  comparative  value  of  different 
Borts  of  hemp,  as  it  regards  durability,  is 
easily  and  speedly  tested  by  any  one, 
since  nearly  all  kinds  are  very  short- 
lived when  exposed  to  causes  favorable 
to  decay.  The  Manilla  will  last  some 
four  or  five  months  as  used  in  the  sum- 
mer season  upon  our  steamboats — the 
Sisal,  which  is  often  sold  in  the  west  as 
manilla,  will  not  last  much  more  than 
half  as  long — the  Eussian  hemp,  when 
kept  moist  and  warm,  will  lose  its  strength 
in  about  three  weeks — the  American 
water-rotted  in  two  weeks,  and  the  dew- 
rotted  in  from  five  to  ten  days.  The  un- 
rotted  hemp,  without  being  kyanized, 
will  not  last  longer  than  the  dew-rotted,  j 
end  will  even  show  more  signs  of  putre-  ' 
faction  before  losing  its  strength. 

The  color  and  appearance  of  this  cord- 
age is  similar  to  the  Russia  or  water-rot- 
ted hemp.  The  strength  is  greater  than 
either,  while  it  is  not  "  frayed  down" 
like  Manilla,  by  friction. 

Dr.  Leavitt  has  devised  a  method  of 

Ereparing  hemp,  which  consists  of  a  hemp- 
rake  of  ingenious  construction  and  great 
strength,  propelled  by  a  steam  engine, 
breaking  hemp  at  the  rate  of  two  pounds 
per  minute,  1200  pounds  in  ten  iiours ; 
and  delivering  the  hemp  in  such  condi- 
tion as  to  be  more  easily  and  speedily 
heckled  upon  the  common  hand-heckle, 
than  the  dew-rotted  hemp  of  the  com- 
mon hand-brake,  and  with  quite  as  little, 
if  not  less  waste.     The  cleaning  appara- 


tus is  also  thought  to  be  likely  to  prove 
equally  effective  when  furnished,  as  its 
simplicity  and  adaptation  seem  to  war- 
rant this  conclusion.  More  than  the 
whole  of  the  fuel  necessary  for  one  steam 
engine,  will  be  furnished,  it  is  said,  from 
the  hemp  itself,  by  three  brakes,  and  is 
supplied  to  the  furnace  without  neces 
sity  of  a  fireman. 

The  hemp-brakes  stand  in  a  line  over 
a  strong  grating,  beneath  which  is  a 
trough,  whose  sides,  inclined  inward,  re- 
ceive and  deposit  upon  an  endless  band, 
running  in  the  direction  of  the  furnace, 
all  the  woody  matter  falling  from  the 
brakes  and  carrying  it  to  a  funnel,  through 
which  it  is  thrown  into  the  furnace  and 
scattered  in  its  bed,  igniting  instantly, 
and  keeping  up  an  intensely  hot  fire. 
A  man  and  two  boys  are  sufficient  to  at- 
tend each  brake  with  ease,  and  a  third 
one  can  bear  off  the  hemp  from  the  three 
brakes,  delivered  in  bands  or  endless 
roving  to  be  passed  through  the  various 
subsequent  machinery,  a  portion  of 
which  is  designed  to  supersede  the  waste- 
ful heckling  now  in  use,  avoiding  the 
manufacture  of  tow  entirely.  Connected 
with  it  is  also  to  be  an  apparatus  for  sup- 
plying the  powerful  antiseptic  substances 
now  in  use  in  the  manufactories  of  ship 
cordage  and  canvas  in  England,  the  effi- 
cacy of  which  has  been  so  severely  tested 
in  the  Niger  expedition,  and. on  the  west- 
ern coast  of  South  America,  so  celebrated 
for  its  production  in  the  cordage  and  sails 
of  shipping  exposed  to  that  climate.  The 
material  to  be  used  will  be  made  at  the 
factory,  and  will  not  cost  over  $5  for  each 
ton  of  hemp. 

Dr.  Leavitt's  efforts  will  prove  of  great 
value  to  our  commercial  interests,  as  weL 
as  probably  greatly  encourage  the  agri- 
culturists whose  attention  is  devoted  to 
the  cultivation  of  hemp,  and  the  amount 
of  this  product  will  doubtless  be  much 
increased  at  the  west. 

By  a  recent  trial  it  appears  that  the 
strength  of  a  rope  of  this  unrotted 
hemp,  was  much  greater  than  those  of 
American  water-rotted  Russia  or  steam 
hemp. 

HEMP-BRAKE.  Mr.  Colver,  of  Mis- 
souri, has  invented  a  hemp-brake,  which 
with  four  men  and  two  boys,  will  break 
2,240  lbs.  in  a  day.  This  machine  is  pre- 
cisely on  the  principle  of  the  hand-brake, 
the  swords  moving  with  great  rapidity. 
On  each  machine  there  are  two  'places 
for  breaking,  and  two  for  cleaning  the 
hemp,  the  ends  of  the  swords  serving 
admirably  for  the  latter  purpose.    The 


246 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[hon 


machine  is  as  simple  as  the  hand-brake, 
as  easily  kept  in  repair,  and  it  can  readi- 
ly be  moved  about  in  the  field. 

The  loss  by  tow,  &c,  is  only  about 
from  12  to  20  per  cent. 

HOE.  In  agriculture  and  gardening, 
an  instrument  for  stirring  the  surface  of 
the  soil,  cutting  annual  weeds  up  by  the 
roots,  and  earthing  up  plants.  The  hand 
hoc  is  a  thin  plate  of  iron,  six  or  eight 
inches  broad,  and  sharpened  on  the  edge, 
fixed  at  right  angles  on  the  extremity  of 
a  pole  or  rod,  which  serves  as  a  handle. 
This  is  called  a  draw  hoe,  because  in  the 
operation  of  hoeing  the  instrument  is 
drawn  or  pulled  towards  the  operator. 
Another  description  of  garden  hoe  has 
the  blade  or  iron  plate  fixed  on  the  extre- 
mity of  the  handle,  and  in  continuation 
of  it ;  and  this  is  called  a  thrust  hoe,  be- 
cause in  hoeing  the  operator  always 
pushes  the  hoe  forward.  This  kind  "is 
also  called  a  Dutch  hoe,  most  probably 
from  having  been  first  introduced  from 
Holland.  In  agriculture  there  are  hoes 
of  the  thrust  kind  drawn  by  beasts  of  la- 
bor, and  commonly  called  horse  hoes. 
In  general  form  they  resemble  a  plough  ; 
but~instead  of  the  share  they  have  one  or 
more  iron  blades,  or  plates  with  sharp 
edges,  fixed  to  perpendicular  iron  rods 
at  their  lower  extremities.  These  sharp- 
ened plates  being  drawn  through  the 
soil,  cut  through  the  roots  of  weeds  an 
inch  or  two  beneath  the  surface.  Agri- 
cultural or  field  hoes  are  only  used  in  the 
case  of  those  field  crops  which  are  sown 
or  planted  in  rows.  There  are  a  great 
many  kinds  of  field  or  horse  hoes  ;  but 
it  is  worthy  of  remark,  that  they  differ 
very  little  in  mechanical  merit.  The  im- 
plement, indeed,  does  not  seem  suscepti- 
ble of  the  same  degree  of  improvement 
as  the  plough  and  the  harrow. 

HOEING.  The  operation  of  stirring 
the  surface,  cutting  off  weeds,  or  earth- 
ing up  plants  with  the  hoe.  In  the  case 
of  any  of  these  operations  dry  weather 
must  be  chosen,  otherwise  the  result 
will  either  be  useless  or  injurious.  Plants 
rooted  up  by  the  hoe  in  wet  weather  will 
produce  fresh  roots  and  grow  again, 
while  plants  earthed  up  under  similar 
circumstances  will  have  the  leaves  which 
are  covered  by  the  soil  decayed  by  it. 
In  either  case,  also,  the  ground  will  be 
hardened  by  the  treading  of  the  feet  of 
men  or  horses,  so  as  to  obstruct  the  pro- 
gress of  the  roots,  and  to  exclude  air  and 
water  from  penetrating  through  it  to 
them-  Hoeing  is  sometimes  performed 
on  surfaces  which  are  without  weeds,  for 


the  purpose  of  stirring  the  soil;  but  in 
such  cases  pronged  hoes,  or  hoes  having 
three  or  more  long  spikes  or  teeth,  are 
more  effective  than  noes  with  broad  plates 
or  blades. 

HOGSHEAD.  An  ancient  measure 
of  capacity,  containing  63  old  wine  gal- 
lons. 

HOLD.  The  inside  of  the  bottom  of 
the  ship.  It  is  divided  into  compart- 
ments by  bulkheads  across  ;  and  contains 
the  ballast,  water,  coal  and  wood,  pro- 
visions, and  cargo. 

HOMBERG'S  PHOSPHORUS.  The 
combination  of  lime  and  muriatic  acid, 
which  remains  after  distilling  the  volatile 
alkali  from  sal  ammoniac,  has  usually 
an  over-proportion  of  lime.  If  it  be 
urged  by  a  violent  heat  it  fuses ;  and 
when  cold  it  has  the  property  of  emitting 
a  phosphoric  light,  when  struck  with  any 
hard  body. 

HONEY,  is  the  product  of  flowers, 
chiefly  of  the  base  of  the  pistil,  where  it 
serves  to  entangle  the  pollen.  It  may, 
by  alcohol,  be  separated  into  two  parts, 
yellow  and  fluid,  and  white  and  solid. 
It  is  separated  from  the  combs  by  heat- 
ing and  stirring  them  in  water,  and  then 
squeezing  the  honey  through  a  cloth. 
Candia  and  the  Levant  produce  the 
best,  in  rocks  and  hollow  trees.  And  it 
is  sometimes  made  from  ripe  grapes,  by 
evaporating  must  to  a  3yrup  ;  or  collect- 
ed from  trees,  as  left  by  other  insects. 
The  whole  economy  of  bees  bespeaks 
design,  purpose,  and  intelligence  in  the 
insects,  under  habits  adapted  to  their 
powers  and  form. 

Honey  differs  much  in  color  and  in 
consistence  ;  it  contains  much  saccharine 
matter,  and,  probably,  some  mucilage, 
from  which  it  derives  its  softness  and 
viscosity.  Honey  very  readily  enters 
into  the  vinous  fermentation,  and  yields 
a  strong  liquor,  called  mead.  There  are 
two  species  of  honey ;  the  one  is  yellow, 
transparent,  and  of  the  consistence  of 
turpentine  ;  the  other  white,  and  capable 
of  assuming  a  solid  form,  and  of  concret- 
ing into  regular  spheres.  These  two 
species  are  often  united;  they  may  be 
separated  by  means  of  alcohol,  which 
dissolves  the  liquid  honey  much  more 
readily  than  the  solid.  Honey  lias  never 
been  accurately  analyzed,  but  some  late 
experiments  go  to  prove  it  to  be  com- 
posed of  sugar,  mucilage,  and  an  acid. 

The  honey  made  in  mountainous  coun- 
tries is  more  highly  flavored  than  that  of 
low  grounds.  The  honey  made  in  the 
spring  is  more  esteemed  than  that  ga- 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


247 


thered  in  the  summer ;  that  of  the  sum- 
mer more  than  that  of  the  autumn. 
There  is  also  a  preference  given  to  that 
of  young  swarms.  Yellow  honey  is  ob- 
tained, by  pressure,  from  all  sorts  of 
honey-combs,  old  as  well  as  new,  and 
even  from  those  whence  the  virgin-honey 
has  been  extracted.  The  combs  are 
broken,  and  heated,  with  a  little  water, 
in  basins  or  pots,  being  kept  constantly 
stirred ;  they  are  then  put  into  bags  of 
thin  linen  cloth,  and  these  in  a  press,  to 
squeeze  out  the  honey.  The  wax  stays 
behind  in  the  bag,  excepting  some  par- 
ticles, which  pass  through  with  the 
honey. 

Honey  is  supposed  to  undergo  no  alte- 
ration in  the  body  of  the  bee,  as  it  retains 
the  odor,  and  not  unfrequently  the  qual- 
ities, of  the  plants  it  was  gathered  from, 
so  that  it  is  sometimes  deleterious,  where 
poisonous  shrubs  abound. 

Honey,   purification   of.     M.  Veling 
recommends  the  white  of  an  egg  to  be 
beaten  up  with  5  lbs.  of  honey  until  it 
froths,  and  water  is  then  added  till  i  t  reach-  I 
es  a  thin  consistence,  then  boiled  till  the  I 
albumen  can  be  removed  with  the  froth,  i 
It  is  then  poured  into  an  upright  vessel  j 
having  a  cork  at  its  lower  part.     It  is 
well  covered,  and  set  aside  in  a  cellar  for 
six  to  eight  weeks.     The  impurities  be- 
come coagulated,  collect  on  the  surface, 
and  the  honey  can  be  drawn  off  clear 
below. 

HONEY  STONE.     A  yellow  mineral 
found  in  octohedral  crystals  at  Artern  in  i 
Thuringia.     It  is  extremely  rare.   It  con-  ; 
sists  of  a  peculiar  acid  (the  melitic  acid)  j 
combined  with  alumina  and  water. 

HOP.    The  Hamulus  lupvlus  of  Lin-  ' 
nseus,  the  female  flowers  of  which  are 
used  for  imparting  a  bitter  flavor  to  malt 
liquors   for  the  purpose  of   preserving 
them  from  fermentation.    The  hop  plant 
is  a  perennial  indigenous  to  Britain  and 
different  parts  of  Europe ;  but,  to  pro- 
duce abundance  of  hops,  it  requires  to  be 
very    carefully  cultivated  in  good  soil, 
and  even  then  is  one  of  the  most  preca- 
rious of  crops.     The  fields  in  which  hops 
are  grown  are  commonly  called  hop  gar- 
dens :  a  loamy  soil  on  a  dry  subsoil  is 
chosen,  and  the  plants  are  placed  in  hills, 
stools,  or  groups  of  three  or  four  in  a 
group,  the  hills  being  in  rows  five  or  six  j 
feet  apart,  and  at  about   the  same  dis-  I 
tance  in  the  row.     A  full  crop  is  not 
produced  till  the  fourth  or  fifth  year  after  j 
planting.    Every  year  the  ground  is  dug  i 
in  winter,  and  kept  clear  of  weeds  during  j 
summer  ;  and  the  hills  have  poles,  gene-  i 


rally  three  or  four  to  a  hill,  for  the  plants 
to  twine  on :  the  purchase  of  these  poles, 
the  fixing  them  in  the  soil  every  spring, 
and  taking  them  down  and  stacking 
them  every  autumn,  and  their  removal 
every  five,  six,  eight,  or  ten  years,  ac- 
cording to  the  kind  of  wood  used,  con- 
stitute a  considerable  part  of  the  expense 
of  hop  culture.  The  hops,  when  mature, 
are  picked  by  hand,  and  as  they  are 
picked  they  are  carried  to  a  drying  kiln, 
dried,  and  packed  into  bags  or  pockets ; 
and  this  is  also  an  expensive  process. 
The  hop  plant  is  particularly  liable  to  be 
injured  by  insects,  by  cold  and  continued 
rains,  and  by  thunder  storms  ;  in  conse- 
quence of  which,  it  is  estimated  that  a 
full  crop  is  not  obtained  oftener  than 
above  once  in  five  years.  Hence  it  is 
easy  to  conceive  that  the  price  of  hops 
must  vary  greatly  in  different  years,  and 
that  the  grower  who  has  a  command  of 
capital  may  profit  largely  by  keeping 
them  back  from  market  when  the  prices 
are  low,  and  only  exposing  them  when 
they  are  high.  In  order  to  keep  hops  for 
two  or  three  years,  they  require  to  be 
powerfully  compressed,  and  put  into 
much  closer  canvas  bags  than  when 
they  are  to  be  sent  immediately  to  mar- 
ket ;  they  also  require  to  be  kept  in  dry 
airy  lofts,  neither  too  warm  nor  too  cold.. 
Hops  are  a  necessary  ingredient  of  malt 
liquor,  as  they  contain  a  rich  bitter,  and 
an  aroma,  which  modifies  the  bitter, 
while  its  astringent  ingredient  destroys 
the  fermentation.  Quassia,  used  as  a 
substitute,  contains  only  the  bitter,  and 
not  the  aroma,  or  the  "astringent,  and 
therefore  fails,  except  when  attempts  are 
made  to  supply  the  other  qualities  of 
hops  by  other  drugs.  Ives  has  separated 
the  aroma  and  tannin  in  a  yellow  pow- 
der, one-sixth  the  weight  of  the  hops,  in 
a  substance  called  lupuline. 

The  strobiles,  or  female  flowers,  are 
dried  in  charcoal  kilns,  till  five  pounds  of 
the  green  flowers  are  reduced  to  one 
pound,  and  they  are  then  laid  in  heaps 
and  bags.  Their  bitter  aromatic  arises 
from  a  substance  called  li/puUn,  forming 
a  sixth  part,  which  may  be  obtained  by 
merely  sifting  with  a  fine  sieve.  They 
yield  also  an  aromatic  oil.  A  pillow  of 
them  is  said  to  promote  sleep,  and  a  fo- 
mentation is  useful  in  tumors. 

Hops  contain  several  elements  of  activ- 
ity, not  in  its  substitutes.  _  Its  bitter 
principle  is  tonic,  its  aromatic  is  warm 
and  stimulant,  and  its  astringent  quality 
precipitates  the  mucilage,  and  thus  re- 
moves the  cause  of  fermentation.    Thest 


248 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hor 


several  properties  render  it  superior  to 
quassia,  gentian,  etc. 

HOKDEIN.     A  modification  of  starch, 
containing  55  per  cent,  of  barley  meal. 

HORN.  The  hollow  horns  of  the  ox, 
goat,  &c,  the  hoof,  the  horny  claw  and 
hail,  and  the  scale  of  certain'insects,  as 
the  shell  of  the  tortoise,  resemble  each 
other  in  chemical  characters  ;  but  they 
differ  very  widely  from  stag's  horn,  ivo- 
ry, &c.  Horn  is  distinguished  from  bone, 
in  being  softened  very  completely  by 
heat,  either  applied  immediately,  or 
through  the  medium  of  water,  so  as  to  be 
readily  bent  to  any  shape,  and  to  adhere 
to  other  pieces  of  horn  m  the  same  state. 
It  contains  but  a  small  portion  of  gela- 
tine, and  in  this  it  differs  from  bone, 
which  contains  a  great  deal.  Horn  con- 
sists chiefly  of  condensed  albumen,  com- 
bined with  a  small  and  varying  portion  of 
gelatine,  with  a  small  part  of  phosphate 
of  lime.  The  fixed  alkalies  readily  dis- 
solve horn  into  a  yellow  saponaceous 
liquor. 

Horn,  Manufacture  of  articles  In. 
Horn,  particularly  of  oxen,  cows,  goats, 
and  sheep,  is  a  substance  soft,  semi-trans- 
parent, and  susceptible  of  being  cut  and 
pressed  into  a  variety  of  forms  ;'it  is  this 
property  that  distinguishes  it  from  bone. 

These  valuable  properties  being  known 
render  horn  susceptible  of  being  em- 
ployed in  a  variety  of  works  fit  for  the 
turner,  comb,  and  snuff-box  maker.  The 
kind  of  horn  most  to  be  preferred,  is 
that  of  goats  and  sheep,  from  its  being 
whiter  and  more  transparent  than  the 
horn  of  any  other  animal.  When  horn  is 
wanted  in  sheets  or  plates,  it  must  be 
steeped  in  water,  to  be  able  to  separate 
the  pith  from  the  kernel,  for  about  fifteen 
days  in  summer,  and  a  month  in  winter  ; 
and  when  it  is  soaked  it  must  be  taken 
oiit  by  one  end  and  well  shaken  and 
rubbed,  in  order  to  get  out  the  pith  ;  af- 
ter which  it  must  be  put  for  hall  an  hour 
in  boiling  water,  and  then  taken  out,  and 
the  surface  sawed  even,  lengthwise  ;  it 
must  again  be  put  into  the  boiling  water 
to  soften  it,  so  as  to  render  it  capable  of 
separating  ;  then  with  the  help  of  a  small 
iron  chisel  it  can  be  divided  into  sheets 
or  leaves.  The  thick  pieces  will  form 
three  leaves,  those  which  are  thin  will 
form  only  two,  whilst  young  horn,  which 
is  only  one  quarter  of  an  inch  thick,  will 
form  only  one.  These  plates  or  leaves 
must  again  be  put  into  the  boiling  water, 
and  when  they  are  sufficiently  soft,  they 
must  be  well  worked  with  a  sharp  cutting 
instrument,  to  render  those  parts  that 


are  thick  even  and  uniform  ;  it  must  be 
put  once  more  into  the  boiling  water, 
and  then  carried  to  the  press.  Mr.  J. 
James  has  contrived  a  method  of  opening 
up  the  horns  of  cattle,  by  which  he 
avoids  the  risk  of  scorching  or  frizzing, 
which  is  apt  to  happen  in  heating  them 
over  an  open  fire.  He  takes  a  solid  block 
of  iron  pierced  with  a  conical  hole,  which 
is  fitted  with  a  conical  iron  plug,  heats 
them  in  a  stove  to  the  temperature  of 
melting  lead,  and  having  previously  cut 
up  the  horn  lengthwise  on  one  side  with 
a  saw,  he  inserts  its  narrow  end  into  the 
hole,  and  drives  the  plug  into  it  with  a 
mallet.  By  the  heat  of  the  irons,  the 
horn  gets  so  softened  in  the  course  of 
about  a  minute,  as  to  bear  flatting  out  in 
the  usual  way. 

At  the  bottom  of  the  press  employed, 
there  must  be  a  strong  block,  in  which  is 
formed  a  cavity  of  nine  inches  square, 
and  of  a  proportionate  depth  ;  the  sheets 
of  horn  are  to  be  laid  within  this  cavity, 
in  the  following  manner  :  at  the  bottom, 
first  a  sheet  of  hot  iron,  upon  this  a  sheet 
of  horn,  then  again  a  sheet  of  hot  iron, 
and  so  on,  taking  care  to  place  at  the  top 
a  plate  of  iron  even  with  the  last,  and 
the  press  must  then  be  screwed  down 
tight. 

There  is  a  more  expeditious  process,  at 
least  in  part,  for  reducing  the  horn  into 
sheets,  when  it  is  wanted  very  even.  Af- 
ter having  sawed  it  with  a  very  fine  and 
sharp  saw,  the  pieces  must  be  put  into  a 
boiler  used  for  the  purpose,  and  then 
boiled  until  sufficiently  soft,  so  as  to  be 
able  to  be  split  with  pincers ;  then  bring 
quickly  the  sheets  of  horn  to  the  press, 
where  they  are  to  be  placed  in  a  strong 
vice,  the  clasps  of  which  are  iron,  and 
larger  than  the  sheets  of  horn,  and  screw 
the  vice  as  quick  and  tight  as  possible  ; 
let  it  then  cool  in  the  press  or  vice,  or  it 
is  as  well  to  plunge  the  whole  into  cold 
water.  The  last  mode  is  preferable,  be- 
cause the  horn  does  not  dry  up  in  cool- 
ing. Now  draw  out  the  leaves  of  horn, 
and  introduce  other  horn  to  undergo  the 
same  process.  The  horn  so  enlarged  in 
pressing  is  to  be  submitted  to  the  action 
of  the  saw,  which  ought  to  be  set  in  an 
iron  frame,  if  the  horn  is  wanted  to  be 
cut  with  advantage,  in  sheets  of  any  de- 
sired thickness,  which  cannot  he  done 
without  adopting  this  mode.  The  thin 
sheets  thus  produced,  must  be  kept  con- 
stantly very  warm  between  the  plates  of 
hot  iron  to  preserve  their  softness.  Every 
leaf  must  be  loaded  with  a  weight  heavy 
enough  to  prevent  its  warping.    To  join 


»] 


CYCLOPEDIA    OF   THE   USEFUL    ARTS. 


249 


the  edges  of  these  pieces  of  horn  to- 
gether, it  is  necessary  to  provide  strong 
iron  moulds  suited  to  the  snape  of  the  ar- 
ticle that  is  wanted,  and  to  place  the  pieces 
in  contact  with  copper  plates,  or  with 
polished  metal  surfaces  against  them  ; 
when  this  is  done,  the  whole  should  be 
put  into  a  vice  and  screwed  up  tight,  then 
plunged  into  boiling  water,  and  after 
some  time  it  is  to  be  removed  from 
thence,  and  immersed  in  cold  water, 
which  will  cause  the  edges  of  the  horn 
to  cement  together,  and  become  perfectly 
united. 

To  complete  the  polish  of  the  bora,  the 
surface  must  be  rubbed  with  sub-nitrate 
of  bismouth,  by  the  palm  of  the  hand. 
The  process  is  short  and  has  this  advan- 
tage— that  it  makes  the  horn  dry  prompt- 
ly. When  it  is  wished  to  spot  the  horn 
in  imitation  of  tortoise  shell,  metallic  so- 
lution must  be  employed  as  follows  :  To 
spot  it  red,  a  solution  of  gold  in  aqua 
regia  must  be  employed  ;  to  spot  it  black, 
a  solution  of  silver  in  nitric  acid  must  be 
used  ;  and  for  brown,  a  hot  solution  of 
mercury  in  nitric  acid.  The  right  side 
of  the  horn  must  be  impregnated  with 
those  solutions,  and  they  wili  assume  the 
color  intended.  The  brown  spots  can  be 
produced  on  the  horn  by  means  of  a  paste 
made  of  red  lead,  with  a  solution  of  pot- 
ash, which  must  be  put  in  pieces  on  the 
horn,  and  subjected  some  time  to  the  ac- 
tion of  heat.  'The  deepness  of  the  brown 
shade  depends  upon  the  quantity  of  pot- 
ash used  in  the  paste,  and  the  length  of 
time  the  mixture  lies  on  the  horn.  A 
decoction  of  Brazil  wood,  a  solution  of 
indigo  with  sulphuric  acid,  a  decoction  of 
saffron,  and  Barbary  tree  wood  is  used. 
After  having  employed  these  materials, 
the  horn  may  be  left  for  half  a  day  in  a 
strong  solution  of  vinegar  and  alum. 

HORNBLENDE.  A  mineral  of  a  dark 
green  or  black  color,  abounding  in  oxide 
of  iron,  and  entering  into  the  composi- 
tion of  several  of  the  trap  rocks.  It  is 
the  amphibole  of  Hauy.  It  often  inclines 
to  brown  with  every  intermediate  shade  ; 
nearly  transparent  in  some  varieties  ;  in 
others  opaque  ;  brittle ;  hardness  about 


the  same  with  feldspar  ;  specific  gravity, 
3-00.  Three  varieties,  analyzed  by  Bons- 
dorf,  gave  the  following  results  : 

White         Green       Black 

Silex 60-31  46-26  45-69 

Magnesia 24-23  19-03  18  79 

Lime 13*66  13-96  13-85 

Almnine 0-26  11-48  1218 

Protoxide  of  iron..     0-15  3-43  7*32 

Do.  of  masnanese.    0*00  9-26  0'22 

Fluoric  acid 0-94  1-60  1-50 

Water,  &c 010  1*04  0-00 

Of  those  varieties  of  the  present  spe- 
cies which  have  obtained  distinct  names, 
aid  which,  in  some  systems  of  mineralo- 
gy, have  ever  been  regarded  as  forming 
separate  species,  the  following  are  the 
most  remarkable,  viz  :  hornblende,  tremo- 
lite,  actynotite,  and  certain  kinds  of  as- 
bestos. 

HORNBLENDE  SCHIST.  A  slaty  va- 
riety of  hornblende,  generally  including 
feldspar  and  grains  of  quartz  :  it  is  of  a 
da^k  green  or  black  color.  Where  clay 
slate  is  in  contact  with  granite,  it  some- 
times passes  into  hornblende  slate. 

HORSE  POWER.  It  is  well  known 
among  engineers  that  a  horse  is  capable 
of  raising  a  weight  of  about  150  lb.  220 
feet  high  in  a  minute,  and  to  continue 
exertions  enabling  him  to  do  that  for  8 
hours  a-day.  < 

Multiply  the  number  of  pounds  by  the 
height  to  which  thev  are  raised  in  a  min- 
ute, 150  X  220  gives  33,000  lb.,  and  the 
power  of  a  horse  is  generally  expressed 
by  a  sum  varying  from  30,000  lb.,  to 
36,000  lb.,  raised  1  foot  high  in  a  minute. 
Bolton  and  Watt  express  it  by  32,000lb.; 
Woolf,  by  36,0001b.;  Tredgold,  Palmer, 
and  others,  by  33,333  lb.  One  horse  can 
draw  horizontally  as  much  as  seven  men. 
In  trains  of  machinery  from  \  to  £  is 
allowed  for  friction  in  calculating  its 
equivalent  of  horse  power. 

HORSE.  Table  of  Power  and  Speed. 
Let  us  suppose  15  to  represent  the  great- 
est unloaded  speed,  ana  the  square  of  15, 
or  225,  to  represent  the  greatest  load 
which  can  be  sustained  without  moving  ; 
the  following  table  gives  for  each  degree 
of  speed,  from  1  to  15,  the  corresponding 
load  and  useful  effect : — 


Load 
Effect 


0  12  3  4  5  6  7  8  9  10  11  12  13  14  15 
25  196  169  144  121  100  81  64  49  36  25  16  9  4  1  0 
0    196    338    432    484    500    486    484     392     324     250    176     108     52       14        0 


Thus,  if  the  greatest  unloaded  speed 
of  a  horse  be  15  miles  an  hour,  and  the 
greatest  weight  he  is  capable  of  sustain- 
ing, without  moving,  be  divided  into  two 
hundred  and  twenty-five  equal  parts,  his 
labor  will  be  most  advantageously  em- 
11* 


ployed  if  he  be  loaded  with  100  of  those 
parts,  and  travel  at  the  rate  of  five  miles 
an  hour.  If  he  be  thus  employed  it  will 
be  found  that  he  will  carry  a  greater 
weight  through  a  distance,  in  a  given 
time,  than  under  any  circumstances. 


250 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ho? 


A  horse,  upon  a  well-constructed  rail- 
road, can  draw  10  tons  at  the  rate  of  2 
miles  per  hour,  or  5  tons  4  miles  per  hour. 

The  absolute  force  of  the  horse  draw- 
ing horizontally  is,  on  average,  770  lb. 
From  various  calculations  it  would  appear 
when  the  period  of  continuance  is  made 
an  element  in  the  calculation,   that  the 

Sower  of  a  horse  working  eight  hours  a 
ay  is  on  an  average  not  more  than  an 
equivalent  to  that  of  five  men  working 
10  hours  ;  the  most  useful  mode  of  ap- 
plying a  horse's  power  is  in  draught,  and 
the  worst  is  in  carrying  a  load;  it  has 
been  found  that  three  men  carrying  each 
100  lb.,  will  ascend  a  hill  with  greater  ra- 
pidity than  one  horse  carrying  300  lb. 
The  best  disposition  of  the  traces  in 
draught  is  when  they  are  perpendicular 
to  the  collar. 

When  a  horse  is  employed  in  moving 
a  machine  in  a  circular  path,  the  diame- 
ter of  this  path  should  not  be  less  than 
25  or  30  feet ;  40  feet  would  be  better 
than  either. 

HUMAN  STRENGTH.  An  active 
man,  working  to  the  best  advantage,  can 
raise  10  lb.  10  feet  in  a  second  for  10 
hours  in  the  day,  100  lb.  one  foot  in  a 
second. 

Absolute  force  of  pressure  with  the 
hands  was  found  by  the  dynamometer  of 
Regnier  to  be  on  an  average  equal  to  100 
lb.  Absolute  force  of  a  man  lifting  with 
both  hands,  286  lb.  The  greatest  ave- 
rage load  which  a  man  can  support  on 
his  shoulders,  for  some  seconds,  is  esti- 
mated at  330  lb. ;  and  it  is  supposed  that 
he  can  exert  the  same  force  in  drawing 
vertically  downwards. 

The  mean  absolute  force  of  a  man,  in 
drawing  or  pulling  horizontally  is  found 
by  the  dynamometer  to  be  110  lb. ;  the 
force  of  the  pull  in  the  strongest  man 
was  found  to  be  only  20  lb.  more  than 
the  average. 

The  greatest  effect  of  man's  strength  in 
raising  a  weight  will  be  when  the  weight 
of  the  man  is  to  that  of  his  load  as  1 :  — 
-T-  V  3,  or  nearlv  as  4  :  3. 

HOSIERY.  The  stocking  frame,  which 
is  the  great  implement  of  this  business, 
though  it  appears  at  first  sight  to  be  a 
complicated  machine,  consists  merely  of 
a  repetition  of  parts  easily  understood, 
with  a  moderate  degree  of  attention, 
provided  an  accurate  conception  is  first 
formed  of  the  nature  of  the  hosiery  fa- 
bric. This  texture  is  totally  different 
from  the  rectangular  decussation  which 
constitutes  cloth,  as  the  slightest  inspec- 


tion of  a  stocking  will  show ;  for  this, 
instead  of  having  two  distinct  systems 
of  thread,  like  the  warp  and  the  weft, 
which  are  woven  together,  by  crossing 
each  other  at  right  angles,  the  whole 
piece  is  composed  of  a  single  thread 
united  or  looped  together  in  a  peculiar 
manner,  which  is  called  stocking- stitch, 
and  sometimes  chain-work. 

A  single  thread  is  formed  into  a  num- 
ber of  loops  or  waves,  by  arranging  it 
over  a  number  of  parallel  needles ;  these 
are  retained  or  kept  in  the  form  of  loops 
or  waves,  by  being  drawn  or  looped 
through  similar  loops  or  waves  formed 
by  the  thread  of  the  preceding  course  of 
the  work.  The  fabric  thus  formed  by 
the  union  of  a  number  of  loops  is  easily 
unravelled,  because  the  stability  of  the 
whole  piece  depends  upon  the  ultimate 
fastening  of  the  first  end  of  the  thread : 
and  if  this  is  undone,  the  loops  formed 
by  that  end  will  open,  and  release  the 
subsequent  loops,  one  at  a  time,  until 
the  whole  is  unravelled,  and  drawn  out 
into  the  single  thread  from  which  it  was 
made.  In  the  same  manner,  if  a  thread 
in  a  stocking-piece  fails,  or  breaks  at  any 
part,  or  drops  a  stitch,  as  it  is  called,  it 
immediately  produces  a  hole,  and  the 
extension  of  the  rest  can  only  be  pre- 
vented by  fastening  the  end.  It  should 
be  observed  that  there  are  many  differ- 
ent fabrics  of  stocking-stitch  for  various 
kinds  of  ornamental  hosiery,  and  as  each 
requires  a  different  kind  of  frame  or 
machine  to  produce  it,  we  should  greatly 
exceed  our  limits  to  enter  into  a  detailed, 
description  of  them  all.  The  species  we 
have  described  is  the  common  stocking- 
stitch  used  for  plain  hosiery,  and  is  form- 
ed by  the  machine  called  the  common 
stocking-frame,  which  is  the  ground- 
work of  all  the  others.  The  operation 
consists  in  drawing  the  loop  of  a  thread 
successively  through  a  series  of  other 
loops,  so  long  as  the  work  is  continued. 

There  is  a  great  variety  of  different 
frames  in  use  for  producing  various  or- 
namental kinds  of  hosiery. 

Rib  stocking-frame.  This  frame,  which, 
next  to  the  common  frame,  is  most  ex- 
tensively in  use,  is  employed  for  work- 
ing those  striped  or  ribbed  3tockings, 
which  are  very  common  in  all  the  dif- 
ferent materials  of  which  hosiery  is 
formed.  In  principle  it  docs  not  differ 
from  the  common  frame,  and  not  greatly 
in  construction.  The  preceding  general 
description  will  nearly  apply  to  this  ma- 
chine with  equal  propriety  as  to  the  for- 


hyd] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


251 


mer;  that  part,  however,  by  which  the 
ribs  or  stripes  are  formed,  is  entirely  an 
addition. 

This  frame  has  been  already  referred 
to  for  the  illustration  of  those  parts  of 
the    machinery  which    are  common   to 
both,  and  those  parts  therefore  require 
no  recapitulation.  The  principle  of  weav-  \ 
ing  ribbed  hosiery  possesses  considera-  j 
ble  affinity  to  that  which  subsists  in  the  I 
weaving  of  that  kind  of  cloth  which  is  j 
distinguished  by  the  name  of  tweeling,  j 
for  the  formation  of  stripes,  with  some 
variation   arising   merely  from  the   dif-  : 
ferent  nature   of  the   fabric.     In  cloth  | 
weaving,  two  different  kinds  of  yarn,  in- 
tersecting each  other  at  right  angles,  are 
employed ;  in  hosiery  only  one  is  used. 
In  the  tweeling  of  cloth,  striped  as  dimi- 
ty, in  the  cotton  or  kerseymere,  and  in 
the  woollen  manufacture,  the  stripes  are 

}>roduced  by  reversing  these  yarns.  In 
losiery,  where  only  one  kind  of  yarn  is 
used,  a  similar  effect  is  produced  by  re- 
versing the  loops.  To  effect  this  revers- 
ing of  the  loops,  a  second  set  of  needles 
is  placed  upon  a  vertical  frame,  so  that 
the  bends  of  the  hooks  may  be  nearly 
under  those  of  the  common  needles. 
These  needles  are  cast 
into  tin  moulds,  pretty 
similar  to  the  former,  but 
more  oblique  or  bevelled 
towards  the  point,  so  as 
to  prevent  obstructions 
in  working  them.  They 
are  also  screwed  to  a  bar 
of  iron,  generally  lighter 
than  the  other,  and  se- 
cured by  means  of  plates : 
this  bar  is  not  fixed,  but 
has  a  pivot  in  each  end, 
by  means  of  which  the 
bar  may  have  a  kind  of  os- 
cillatory motion  on  these 
pivots.  The  two  frames 
of  iron  support  this  bar;  that  in  which  it 
oscillates  being  nearly  vertical,  but  inclin- 
ed a  little  towards  the  other  needles.  This 
figure,  which  is  a  profile  elevation,  will 
serve  to  illustrate  the  relative  position  of 
each  bar  to  the  other.  The  vertical  frame 
at  a  is  attached  to  the  horizontal  frame 
d,  by  two  centre  screws,  which  serve  as 
joints  for  it  to  move  in.  On  the  top  of 
this  frame  is  the  rib-needle  bar  at/,  and 
one  needle  is  represented  at/".  At  g is  a 
small  presser.  to  shut  the  barbs  or*  the 
rib-needles,  in  the  same  manner  as  the 
large  one  does  those  of  the  frame.  At  h 
is  one  of  the  frame-needles,  to  show  the 
relative  position  of  the  one  set  to  the 


other.  The  whole  of  the  rib-bar  is  not 
fitted  with  needles  like  the  other ;  for 
here  needles  are  only  placed  where  ribs 
or  stripes  are  to  be  formed,  the  intervals 
being  filled  up  with  blank  leads,  that  is 
to  say,  with  sockets  of  the  same  shape  as 
the  others,  but  without  needles;  being 
merely  designed  to  fill  the  bar  and  pre- 
serve the  intervals.  Two  small  handles 
depend  from  the  needle-bar,  by  which 
the  oscillatory  motion  upon  the  upper 
centres  is  given.  The  rising  and  sinking 
motion  is  communicated  to  this  machine 
by  chains  which  are  attached  to  iron 
sliders  below,  and  which  are  wrought  by 
the  hosier's  heel  when  necessary.  The 
pressure  takes  place  partly  by  the  action 
of  the  small  presser,  and  partly  by  the 
motion  of  the  needles  in  descending.  A 
small  iron  slider  is  placed  behind  the 
rib-needles,  which  rises  as  they  descend, 
and  serves  to  free  the  loops  perfectly 
from  each  other. 

In  the  weaving  of  ribbed  hosiery,  the 
plain  and  rib  courses  are  wrought  alter- 
nately. When  the  plain  are  finished, 
the  rib-needles  are  raised  between  the 
others,  but  no  additional  stuff  is  sup- 
plied. The  rib-needles,  intersecting  the 
plain  ones,  merely  lay  hold  of  the  last 
thread,  and,  by  again  bringing  it  through 
that  which  was  on  the  rib-needle  before, 
give  it  an  additional  looping,  which  re- 
verses the  line  of  chaining,  and  raises 
the  rib  above  the  plain  intervals,  which 
have  only  received  a  single  knitting. 

HYALITE,  Manufacture  of.  This 
name  is  given  to  a  black  glass  first  made 
in  Bohemia,  in  1820,  by  M.  de  Buquoi. 
To  prepare  it,  it  is  necessary  to  add  to  the 
materials  for  white  glass,  a  quantity  of 
iron  forge  cinder  powder,  charcoal  dust 
in  excess,  and  calcined  bone  powder. 
The  forge  cinder  may  be  replaced  by  ba- 
salt, or  lava.  If  sufficient  charcoal  is  not 
present,  the  glass  takes  a  green  color.  A 
red  hyalite  may  be  obtained  with  cal- 
cined bone  powder,  oxide  of  copper,  car- 
bon, &c,  and  all  these  varieties  present 
a  marbled  structure  upon  cutting.  These 
glasses  are  very  beautiful:  they  are  fit 
to  take  the  place  of  porcelain  m  many 
cases,  possess  far  more  lustre,  and  can 
receive  a  more  perfect  polish. 

HYDRARG^LLITE.  A  name  given 
to  the  native  phosphate  of  alumina,  under 
the  erroneous  idea  that  it  consisted  of 
alumina  and  water. 

HYDRATES.  Compounds  containing 
water  as  one  of  their  proximate  elements, 
and  in  definite  proportion.  Caustic  pot- 
ash is  a  hydrate  of  jootaasa^  composed  of 


252 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hyd 


1  equivalent  ot  potassa  =  48,  and  1  of 
water  =  9.  Slaked  lime,  which  is  an  ap- 
parently dry  white  powder,  is  a  hydrate 
of  lime. 

HYDKAULIC  RAM,  or  WATER 
RAM.  An  ingenious  hydraulic  machine 
for  raising  water  by  means  of  its  own 
impulse.  The  principle  of  its  action  and 
the  mechanism  of  its  construction  may 
be  described  as  follows  : 


The  water  arriving  at  A  from  the  re- 
servoir with  the  velocity  due  to  the 
hei.ght  of  the  fall,  passes  aloner  the  pipe 
A  B,  which  should  have  an  inclination 
of  at  least  an  inch  for  every  two  yards, 
escapes  through  an  orifice  C,  which  may 
be  shut  at  pleasure  by  means  of  a  valve. 
A  reservoir,  F,  filled  with  air,  is  attached 
by  means  of  a  cylinder,  abed,  to  the 
pipe  A  B  D;  in  the  middle  of  the  bottom 
of  the  reservoir  F  is  a  circular  orifice,  to 
which  there  is  adapted  a  short  cylindri- 
cal tube,  of  which  the  extremity  E  is 
also  furnished  with  a  valve.  Another 
valve,  S,  serves  to  supply  the  air  to  the 
space  comprised  between  the  cylinder 
abed  and  the  tube  E.  G  I  H  is  an  as- 
censional tube  rising  from  the  reservoir 
F.  The  water  which  escapes  at  C  is  car- 
ried off  by  the  waste  pipe  K  L. 

The  form  of  this  apparatus  (or  perhaps 
its  mode  of  action)  suggested  the  name 
it  has  received.  The  pipe  A  B  C  is  called 
the  body  of  the  ram  ;  and  the  extremity, 
where  the  valves  and  the  reservoir  F  are 
placed,  is  called  its  head.  Both  valves 
D  and  E  are  formed  of  hollow  balls  sup- 
ported on  muzzles,  and  of  such  a  thick- 
ness of  metal  that  they  weigh  about  twice 
as  much  as  the  quantity  "of  water  they 
displace. 

We  may  now  consider  the  effects  of 
the  engine  when  in  action.  The  water, 
flowing  through  the  orifice  G,  acquires  the 
velocity  due  to  the  height  of  the  fall,  and 
raises  the  ball  D  from  its  support  till  it 
comes  to  the  orifice  C ;  the  extremity  of 
this  orifice  is  covered  with  leather,  or 
with  cloth  filled  with  pitch,  so  that  when 
the  ball  is  applied  to  it,  the  passage  of 
the  water  is  effectually  prevented.    As 


soon  as  this  orifice  is  closed,  the  water 
raises  the  ball  E  which  had  shut  the  ori- 
fice of  the  reservoir  F,  and  a  portion  of 
it  introduces  itself  into  this  reservoir, 
and  into  the  pipe  G  I  H.  It  thus  loses 
the  velocity  which  it  had  when  the  ori- 
fice C  was  shut,  and  the  balls  D  and  E 
fall  down  in  consequence,  the  one  on  its 
support,  and  the  other  on  the  orifice  at 
E.  When  this  takes  place,  every  thing 
is  in  the  same  state  in  which  it  was  at 
first.  The  water  begins  again  to  flow 
through  the  orifice  C;  the  valve  D  is 
again  shut ;  and  the  same  effects  are  re- 
peated in  an  interval  of  time,  which,  for 
the  same  ram,  undergoes  little  variation. 
Every  time  the  impulse  is  renewed,  a 
quantity  of  water  is  forced  up  into  the 
reservoir  F  and  the  tube  H ;  and  as  it  is 
prevented  from  returning  by  the  action 
of  the  valve,  it  must  necessarily  be  deli- 
vered at  the  extremity  of  H.  The  use  of 
the  air-vessel  F  is  to  keep  up  a  continu- 
ous motion  of  the  ascending  column  of 
water.  The  communication  with  the  ex- 
ternal atmosphere  being  cut  off,  the  air 
within  F  is  compressed  by  a  force  pro- 
portional to  the  height  of  the  surface  of 
the  water  in  II  above  its  surface  in  F ; 
and  this  compressed  air,  acting  by  its 
elasticity  on  the  water,  maintains  a  con- 
tinuous flow  through  H.  The  air-vessel, 
however,  though  it  assists  the  action  of 
the  ram,  is  not  an  essential  part  of  it ; 
the  continuity  of  the  discharge  of  water 
may  be  effected  by  means  of  two  or  more 
rams,  of  which  the  ascensional  pipes  G  I 
H  all  terminate  in  a  single  branch.  On 
this  principle  works  have  been  erected  at 
Marly,  in  France,  which  raise  water  in  a 
continuous  jet  to  the  height  of  57  metres, 
or  187  English  feet. 

As  the  ascending  column  of  water  com- 
municates with  the  air  in  the  reservoir 
F,  this  would  soon  be  exhausted  if  a 
fresh  portion  of  air  were  not  introduced 
at  each  stroke  of  the  ram.  The  little  tube 
S,  which  is  stopped  by  a  valve  opening 
inwards,  serves  for  this  purpose.  At  the 
instant  when  the  orifice  C  is  closed  a  re- 
coil takes  place,  by  which  the  water  is 
thrown  back  from  the  head  of  the  ram  to- 
wards the  cistern  ;  and  a  partial  vacuum 
being  thus  produced  within  the  cylinder 
abed,  the  pressure  of  the  external  at- 
mosphere forces  open  the  valve  in  the 
canal  S,  and  a  portion  of  air  enters  the 
cylinder,  whence  it  is  driven  into  the  re- 
servoir, excepting  the  small  part  of  it 
which  lodges  in  the  space  between  the 
cylinder  abed  and  the  tube  E. 

The  invention  of  the  hydraulic  ram, 


>] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


253 


at  least  in  the  improved  form  here  de- 
scribed, belongs  to  Montgolfier,  of  Mont- 
pelier.  A  machine,  however,  on  the 
same  principle  had  previously  been  sug- 

?ested,  and  even  erected  at  Chester  (Eng.), 
y  Mr.  Whitehurst,  but  much  less  perfect 
in  its  mode  of  action ;  for  the  orifice  C, 
instead  of  being  opened  and  shut  by  the 
action  of  the  water  itself,  required  to  be 
opened  and  shut  by  the  hand  by  means 
of  a  stop-cock.  Owing  to  this  circum- 
stance, Whitehurst's  machine  was  of  lit- 
tle utility,  and  appears  to  have  soon  been 
entirely  forgotten. 

HYDKAULIC  PRESSURE  EN- 
GINES. A  Mr.  Glynn  brought  under  the 
notice  of  the  British  Association  in  1849 
the  means  of  employing  high  falls  ofwater 
to  produce  reciprocating  motion,  by  means 
of  a  pressure  engine  ;  this  latter  acted  on 
by  the  power  of  a  descending  column  of 
water  upon  the  piston  of  a  cylinder  to 
give  motion  to  pumps  for  raising  water 
to  a  different  level,  or  to  produce  a  re- 
ciprocating motion  for  other  purposes. 
The  pressure  engine  was  calculated  to 
give  great  mechanical  effect  in  cases 
where  water-falls  exist  of  much  too  great 
a  height  and  too  small  a  volume  to  be 
practically  used  efficiently  on  water 
wheels  within  the  ordinary  limits  of  di- 
ameter. One  of  these  engines  is  at  pres- 
ent worked  at  the  Allport  Mines,  Derby- 
shire. The  cylinder  is  50  inches  di- 
ameter, and  the  stroke  10  feet,  worked 
by  a  column  of  water  132  feet  high,  so 
that  the  proportion  of  power  to  act  on  it 
was  the  area  of  a  piston  to  that  of  the 
plunger,  namely,  1,963  to  1,385,  or  fully 
70  per  cent.  The  engine  lever  cost  60 
dollars  a  year  since  its  erection  in  1841. 
Its  usual  speed  is  5  strokes  per  minute, 
but  can  work  7  without  any  concussion 
in  the  descending  column.  The  duty  ac- 
tually done  being  equal  to  163  horse 
power.  Area  of  plunge  9-621  feet  X  10 
~  7  strokes  ==  673-41.  673-41  X  62-5  H- 182 
==  5  5  5  5^^  2  —  163  horse  power. 

In  this  engine  as  in  others,  when  water 
acts  by  its  gravity  or  pressure,  these  ma- 
chines do  the  best  work  when  the  water 
enters  the  machine  without  shock  or  im- 
pulse, and  leaves  it  without  velocity, 
obtaining  thus  all  the  available  power 
that  the  water  can  yield  with  the  least 
loss  of  effect.  This  result  is  best  accom- 
plished by  making  the  pipes  and  passages 
of  sufficient  size  to  prevent  acceleration 
of  the  hydrostatic  column. 

The  pressure  of  a  small  column  of  wa- 
ter, as  that  of  a  common  hydrant  pipe, 
has  been  made  to  turn  a  coffee-mill,  which 


it  works  economically  and  efficiently. 
There  arc  many  small  machines  which 
might  readily  be  turned  by  the  Croton 
water  in  New  York,  and  also  in  other 
large  cities  by  the  mere  descending  force 
of  the  small  hydrant  or  hose  pipe.  It 
would  be  in  cities  one  of  the  simplest 
and  le.ist  expensive  powers. 
HYDRIOD1C  ACID.  ^  A  gaseous  com- 

Eound  of  hydrogen  and  iodine,  obtained 
y  the  mutual  decomposition  of  iodide 
of  phosphorus  and  water.  It  is  com- 
posed of  126  iodine  +  1  hydrogen  ;  and 
its  equivalent,  therefore,  is  127.  The 
specific  gravity  of  this  gas  is  4-4.  One 
hundred  cubic  inches  weigh  136  grains. 
It  is  rapidly  absorbed  by  water,  furnish- 
ing a  sour,  colorless,  and  dense  liquid, 
winch  soon  becomes  brown  by  exposure 
to  air,  in  consequence  of  the  evolution 
of  a  little  free  iodine.  It  is  instantly  de- 
composed by  chlorine,  which  abstracts 
the  hydrogen  to  form  hydrochloric  (mu- 
riatic) acid,  and  sets  the  iodine  free. 

HYDEOBROMIC  ACID.  A  gaseous 
acid  composed  of  78  bromine  +  1  hydro- 
gen. It  is  obtained  by  the  mutual  de- 
composition of  bromide  of  phosphorus 
and  water. 

HYDROCARBON.  A  term  applied 
by  chemists  to  compounds  of  hydrogen 
and  carbon.  These  elements  unite  in 
several  proportions,  and  form  a  variety 
of  curious  definite  combinations,  which 
are  commonly  called  hydrocarburets. 

IIYDROCARBURETS.  Compounds 
of  hydrogen  and  carbon.  These  appear 
to  be  several  definite  combinations  of 
these  elements  ;  among  them  the  follow- 
ing deserve  especial  notice  :  1.  Light  car- 
buretted  hydrogen  gas,  which  is  the  fire- 
damp of  coal  mines  and  of  marshes  :  100 
cubic  inches  weigh  about  17-4 grains.  It 
consists  of  two  atoms  of  hydrogen  =  2, 
and  1  of  carbon  =  6  ;  its  equivalent  is  8.  It 
burns  with  a  pale  blue  flame.  2.  Olefiant 
gas,  which  is  formed  during  the  distilla- 
tion of  equal  measures  of  alcohol  and  sul- 
phuric acid :  100  cubic  inches  weigh  30-5 
grains.  It  is  composed  of  2  atoms  of 
hydrogen  =  2,  and  2  of  carbon  =  12 ;  and 
its  equivalent,  therefore,  is  14.  It  burns 
with  a  bright  white  flame.  Coal  gas  con- 
sists of  a  mixture  of  these  two  hydrocar- 
bons. The  term  olejiunt  gas  is  derived 
from  the  action  of  chlorine  upon  it, 
which,  when  mixed  with  the  gas  over 
water,  gradually  condenses  it  into  a  liquid 
looking  like  oil,  which  is  a  hydrochloride 
of  carbon.  3.  Quadricarburetted  hydro- 
gen, which  is  produced  during  the  de- 
structive distillation  of  oil  (Faraday,  An,' 


254 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hyg 


rials  of  Philosophy,  xxvii,,  44),  and  which 
is  a  vapor  condensable  at  0°,  of  which  100 
cubic  inches  weigh  61-2  grains.  It  con- 
sists of  4  atoms  of  hydrogen  =  4,  and  4 
of  carbon  =  24  ;  and  its  equivalent  is  28. 
It  burns  with  a  dense  and  very  smoky 
flame.  This  compound  has  also  been 
called  etherine,  1  volume  of  the  vapor  of 
of  ether  being  constituted  of  1  volume  of 
quadrihydrocarbon  and  1  of  water  vap>jr. 
4.  Bicarburet  of  hydrogen,  obtained,  like 
the  last,  from  the  volatile  products  formed 
during  the  destructive  distillation  of 
whale  oil.  When  the  quadrihydrocarbon 
has  been  distilled  off  from  the  more  vola- 
tile portion,  that  which  remains  yields  a 
Eroduct  which  congeals  at  0°.  It  is  a 
rittle  white  solid  at  that  temperature  : 
100  cubic  inches  of  its  vapor  weigh  85*3 
grains,  and  it  consists  of  3  atoms  of  hy- 
drogen =  3,  and  6  of  carbon  =  36  ;  its 
equivalent,  therefore,  is  39.  These  are 
the  principal  forms  of  hydrocarbon  which 
have  been  satisfactorily  identified :  they 
all  afford  carbonic  acid  and  water  when 
burned  in  a  sufficiency  of  oxygen  ;  and 
the  proportions  in  which  these  are  formed, 
together  with  the  specific  gravities  of 
their  respective  vapors,  furnish  the  data 
upon  which  their  composition  is  estima- 
ted.   See  Naptha  and  Napthalin. 

HYDROMETER.  An  instrument  for  de- 
termining the  specific  gravities  of  liquids, 
and  thence  the  strengths  of  spirituous 
liquors  ;  these  being  inversely  as  their 
specific  gravities.  Various  instruments 
of  different  forms  have  been  proposed 
for  ascertaining  readily  the  specific  gravi- 
ties of  fluids  ;  but  as  Sikes's  hydrometer 
is  directed  by  act  of  parlia- 
ment to  be  used  in  collect- 
ing the  revenue  of  Great 
©Britain,  it  may  be  consider- 
B  ed  as  more  deserving  of  de- 
scription than  any  of  the  oth- 
ers. This  instrument  is  rep- 
resented in  the  annexed  fig- 
ure. A  B  is  a  flat  stem,  divi- 
ded on  both  sides  into  eleven 
equal  parts,  each  of  which  is 
again  subdivided  into  two. 
The  stem  carries  a  hollow 
brass  ball  B  C,  in  which  is 
fixed  a  conical  stalk  C  D,  ter- 
minating in  a  pear-shaped 
bulb  D.  Eight  different 
weights  of  a  circular  form, 
nnd  marked  with  the  nmmbers  10,  20,  30, 
40,  50,  60,  70,  and  80,  are  cut  in  the  man- 
ner represented  at  W,  so  that  they  can  be 
placed  on  the  stalk  C  D.  When  the 
strength  of  spirits  is  to  be  measured,  one 


of  the  circular  weights  is  placed  on  C  D, 
which  is  found  by  trial  to  be  capable  of 
sinking  the  ball  so  far  that  the  surface 
of  the  liquid  cuts  the  stem  at  one  of  the 
divisions  between  A  and  B.  The  num- 
ber of  this  division  is  then  observed,  and 
also  the  temperature  of  the  liquid ;  and 
the  corresponding  strength  per  cent,  of 
the  spirits  is  then  found  in  a  table  which 
accompanies  the  instrument. 

Another  easy  method  of  determining 
the  destinies  of  different  liquids,  fre- 
quently practised,  is  by  means  of  a  set  of 
glass  beads  previously  adjusted  and 
numbered.  Thrown  into  any  liquid,  the 
heavier  balls  sink  and  the  lighter  float  at 
the  surface  ;  but  one  of  them  approach- 
ing the  density  of  the  liquid  will  be  in  a 
state  of  indifference  as  to  buoyancy,  or 
will  float  under  the  surface.  The  number 
on  this  ball  indicates,  in  thousandth  parts, 
the  specific  densitv  of  the  liquid. 

HYDROSTATIC  PRESS,  also  called 
the  Hydraulic  Press,  and  sometimes  from 
the  name  of  the  engineer  who  gave  it  the 
form  under  which  it  is  now  constructed, 
and  brought  it  into  general  use,  BramaKs 
Press,  is  a  machine  by  means  of  which 
an  enormous  force  of  pressure  is  obtained 
through  the  medium  of  water.  The 
principle  is  the  same  as  that  of  the  hy- 
drostatic bellows  ;  from  which,  indeed,  it 
only  differs  by  the  substitution  of  a 
strong  forcing  pump  for  the  long  tube, 

and  a  barrel  and   ^ 7 

piston  for  the 
leather  and  boards. 
It  consists  of  a 
short  and  very 
strong  pump-bar- 
rel A  B,   with    a 


solid  piston  C  of  proportionate  strength, 
which  is  pushed  upwards  against  the 
thing  to  be  compressed,  by  water  driven 
iuto  the  barrel  beneath  it  at  F  from  the 
small  forcing  pump  E.  If  the  small  pump 
have  only  one  thousandth  of  the  area  of 
the  large  barrel,  and  if  a  man,  by  means 
of  its  lever  handle  D,  press  its  piston 
down  with  a  force  of  five  hundred  pounds, 
the  piston  of  the  great  barrel,  in  virtue 
of  the  hydrostatic  principle  of  equal  pres- 
sure in  all  directions,  will  riso  with  a  force 
of  a  thousand  times  five  hundred  pounds, 
or  more  than  200  tons.  The  hydrostatic 
press  is  applied  to  a  great  variety  of  useful 
purposes ;  for  compressing  bales  of  goods, 
as  paper,  cotton,  wool,  tobacco,  &c,  for 
expressing  oils  from  seeds,  raising 
weights,  uprooting  trees,  &c. 

HYGROMETER,   or  Dew-Measurer, 
is  an  instrument  for  measuring  the  de- 


HYDROSTATIC    1'RESS.       p    26,1. 


hyg] 


CYCLOPEMA    OF    THE    USEFUL    ARTS. 


255 


grecs  of  moisture  or  dryness  of  the  at- 
mosphere. 

Variations  in  the  state  of  the  atmos- 
phere with  respect  to  moisture  and  dry- 
ness are  manifested  by  a  great  variety  of 
phenomena  ;  and,  accordingly,  numerous 
contrivances  have  been  proposed  for  as- 
certaining the  amounts  or  those  variations 
by  referring  them  to  some  conventional 
scale.  All  such  contrivances  are  called 
hygrometers  ;  but  though  the  variety  of 
form  that  may  be  given  to  them,  or  of 
substances  that  may  be  employed,  is  end- 
less, they  may  all  be  referred  to  two 
classes  ;  namely,  1st,  those  which  act  on 
the  principle  of  absorption  ;  and,  2d,  those 
which  act  on  the  principle  of  condensation. 

1.  Hygrometers  on  trie  Principle  of  Ab- 
sorption.— Many  substances  in  each  of  the 
three  kingdoms  of  nature  absorb  moist- 
ure from  the  atmosphere  with  greater  or 
less  avidity,  and  thereby  suiter  some 
change  in  their  dimensions,  or  weight, 
or  some  of  their  physical  properties.  An- 
imal fibre  is  sottened  and  relaxed,  and 
consequently  elongated,  by  the  absorp- 
tion of  moisture.  Cords  composed  of 
twisted  vegetable  substances  are  swollen, 
and  thereby  shortened,  when  penetrated 
by  humidity ;  and  the  alternate  expan- 
sion and  shrinking  of  most  kinds  of  wood, 
especially  when  used  in  cabinet-work, 
and  after  the  natural  sap  has  been  evapo- 
rated, is  a  phenomenon  with  which  every 
one  is  familiar.  Many  mineral  substan- 
ces absorb  moisture  rapidly,  and  thereby 
obtain  an  increase  of  weight.  Now  it  is 
evident  that  any  of  these  changes,  either 
of  dimension  or  of  weight,  may  be  re- 
garded as  the  measure  of  the  quantity  of 
moisture  absorbed,  from  which  the  quan- 
tity of  water  existing  in  the  atmosphere 
in  the  state  of  vapor  is  inferred;  but 
many,  indeed  the  far  greater  part  of  them, 
are  so  small  in  amount,  or  take  place  so 
slowly,  that  they  afford  no  certain  indica- 
tion of  the  actual  state  of  the  atmosphere 
at  any  particular  moment. 

Of  the  different  kinds  of  hygrometers 
whose  construction  depends  on  change 
of  dimensions,  arising  foom  the  absorp- 
tion of  moisture,  there  are  two  deserving 
of  notice  on  account  of  their  historical 
celebrity,  though  they  are  now  seldom, 
if  at  all,  used  where  accurate  meteorolo- 
gical observations  are  attempted.  One  is 
the  hair  hygrometer  of  Saussure ;  the 
other  the  whalebone  hygrometer  of  DeLuc. 

Saussure's  hygrometer  consists  of  a 
human  hair  prepared  by  boiling  it  in  a 
caustic  ley.  One  extremity  of  the  hair  is 
fastened  to  a  hook,  or  held  by  pincers  ; 


the  other  has  a  small  weight  attached  to 
it,  by  which  it  is  kept  stretched.  The 
hair  is  passed  over  a  grooved  wheel  or 
pulley,  the  axis  of  which  carries  an  index 
which  moves  over  a  graduated  arch. 
Such  is  the  essential  part  of  the  instru- 
ment, and  it  is  easy  to  conceive  how  it 
acts.  When  the  surrounding  air  becomes 
more  humid,  the  hair  absorbs  an  addi- 
tional quantity  of  moisture,  and  is  elon- 
the  counterpoise  consequently  de- 


scends, and  turns  the  pulley,  whereby 
the  index  is  moved  towards  the  one  hand 
or  the  other.  On  the  contrary,  when  the 
air  becomes  drier,  the  hair  loses  a  part 
of  its  humidity,  and  is  shortened.  The 
counterpoise  is  consequently  drawn  up, 
and  the  index  moves  in  the  opposite  di- 
rection. The  accuracy  of  the  indications 
of  this  instrument  depends  on  the  as- 
sumed principle  that  the  expansion  and 
contraction  of  the  hair  are  due  to  moisture 
alone,  and  are  not  affected  by  tempera- 
ture or  other  changes  in  the  condition  of 
the  atmosphere.  Experiment  shows  that 
the  influence  of  temperature  is  not  very 
great ;  but,  after  all  precautions  have 
been  taken  in  preparing  the  instrument, 
it  is  found  to  be  exceedingly  irregular  in 
its  movements,  and  subject  to  great  un- 
certainties. Besides,  the  substance  is 
soon  deteriorated,  and  will  scarcely  main- 
tain its  properties  unimpaired  during  a 
single  year. 

The  hygrometer  of  De  Luc  consists  of 
a  very  thin  slip  of  whalebone  cut  trans- 
versely or  across  the  fibres,  and  stretched 
by  means  of  a  spring  between  two  points. 
One  end  is  fixed  to  a  bar,  while  the  other 
acts  on  the  shorter  arm  of  the  index  of  a 
graduated  scale.  When  the  whalebone 
absorbs  moisture  it  swells,  and  its  length 
is  increased  ;  as  it  becomes  dry  it  con- 
tracts ;  and  the  space  over  which  the  in- 
dex moves  by  the  one  or  the  other  of 
these  effects  gives  the  measure  of  the  ex- 
pansion or  contraction,  and  the  corre- 
sponding change  in  the  hygometric  state 
of  the  atmosphere.  The  action  of  this 
hygrometer  appears  to  be  more  uncertain 
than  that  of  Saussure. 

The  hygrometers  which  have  been  pro- 
posed on  the  principle  of  a  change  of 
weight  arising  from  the  absorption  of 
moisture,  are  liable  to  still  greater  ob- 
jections. Changes  of  weight  may  indeed 
be  measured  with  greater  accuracy  by  the 
common  or  torsion  balance :  but  in  the 
present  case  they  are  so  small,  that  the 

Sarticies  of  dust  which  are  at  all  times 
oating  in  the  atmosphere  may  produce 
a  great  alteration  in  the  results.    A  great 


256 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[hyo 


variety  of  substances  which  attract  moist- 
ure have  been  employed,  such  as  sponge, 
cotton,  bibulous  paper,  caustic  potash, 
the  deliquescent  salts,  sulphuric  acid, 
&c.  •  but  the  indications  which  they  give 
are  deserving  of  very  little  credit.  Chan- 
ges of  property  indicated  by  the  torsion 
of  cords  formed  of  gut,  hemp,  cotton, 
&c,  and  the  torsion  of  certain  vegetable 
fibres,  are  still  more  fallacious. 

2.  Hygrometers  on  the  Principle  of  Con- 
densation.— The  instruments  of  this  class 
are  of  a  far  more  refined  nature  than 
those  which  we  have  been  describing. 
In  order  to  give  an  idea  of  the  general 
principle  on  which  they  depend,  let  us 
conceive  a  glass  jar,  having  its  sides  per- 
fectly clean  and  transparent,  to  be  filled 
with  water,  and  placed  on  a  table  in  a 
room  where  the  temperature  is,  for  exam- 
ple, 60°,  the  temperature  of  the  water 
being  the  same  as  that  of  the  room.  Let 
us  next  suppose  pieces  of  ice,  or  a  freez- 
ing mixture,  to  be  thrown  into  the  water, 
whereby  the  water  is  gradually  cooled 
down  to  55,  50,  45,  &c,  degrees.  As  the 
process  of  cooling  goes  on,  there  is  a  cer- 
tain instant  at  which  the  jar  loses  its 
transparency,  or  becomes  cum ;  and,  on 
attentively  examining  the  phenomenon, 
it  is  found  to  be  caused  by  a  very  fine 
dew  or  deposition  of  aqueous  vapor  on 
the  external  surface  of  the  vessel.  The 
precise  temperature  of  the  water,  and, 
consequently,  of  the  vessel,  at  the  instant 
when  this  deposition  begins  to  be  form- 
ed, is  called  the  dew  point,  and  is  capable 
of  being  noted  with  great  precision.  Now 
this  temperature  is  evidently  that  to 
which,  if  the  air  were  cooled  down,  under 
the  same  pressure,  it  would  be  complete- 
ly saturated  with  moisture,  and  ready  to 
deposit  dew  on  any  body  in  the  least  de- 
gree colder  than  itself.  The  difference, 
therefore,  between  the  temperature  of  the 
air,  and  the  temperature  of  the  water  in 
the  vessel  when  the  dew  begins  to  be 
formed,  will  afford  an  indication  of  the 
dryness  of  the  air,  or  of  its  remoteness 
from  the  state  of  complete  saturation. 

But  the  observation  which  has  now 
been  described  is  capable  of  affording  far 
more  interesting  and  precise  results  than 
a  mere  indication  of  the  comparative  dry- 
ness or  moisture  of  the  atmosphere. 
With  the  help  of  tables  of  the  eh^tic 
force  of  aqueous  vapor  at  different  im- 
peratures,  it  gives  the  means  of  deter- 
mining the  absolute  weight  of  the  aque- 
ous vapor  diffused  through  any  given 
volume  of  air,  the  proportion  of  vapor 
existing  in  that  volume  to  the  quantity 


that  would  be  required  to  saturate  it,  and 
of  measuring  the  force  and  amount  of 
evaporation. 

The  elastic  force  of  aqueous  vapor  at 
the  boiling  point  of  water  is  evidently 
equal  to  the  pressure  of  the  atmosphere. 
This  may  be  assumed  as  corresponding 
to  a  column  of  mercury  30  inches  in 
height.  Mr.  Dalton,  in  the  fifth  volume 
of  the  Manchester  Memoirs,  has  given  the 
details  of  a  most  valuable  and  beautiful 
set  of  experiments,  by  which  he  ascer- 
tained the  elastic  force  of  vapor  from 
water  at  every  degree  between  its  freez- 
ing and  boiling  points  in  terms  of  the 
column  of  mercury  which  it  is  capable  of 
supporting.  As  the  same  experiments 
have  since  been  frequently  repeated,  and 
the  different  results  present  all  the  ac- 
cordance which  can  be  expected  in  so 
delicate  an  investigation,  the  tension  of 
vapor  at  the  different  temperatures  may 
be  regarded  as  sufficiently  well  determin- 
ed. Supposing,  then,  we  have  a  table 
exhibiting  the  elasticity  or  tension  corre- 
sponding to  every  degree  of  the  thermo- 
meter, the  weight  of  a  given  volume  of 
vapor,  for  example  a  cubic  foot,  may  be 
determined  as  follows : 

Steam  at  212°,  and  under  a  pressure  of 
30  inches  of  mercury,  is  1700  times  light- 
er than  an  equal  bulk  of  water  at  its 
greatest  density,  or  a  temperature  of 
about  40°,  and  a  cubic  foot  of  water  at 
that  temperature  weighs  437272  grains ; 
the  weight,  therefore,  of  a  cubic  foot  of 
steam  at  that  temperature  and  pressure 
is  437272-5-1700=257-218  grains.  Hence 
we  may  find  the  weight  of  an  equal  bulk 
of  vapor  of  the  same  temperature  under 
any  other  given  pressure,  suppose  0-56 
of  an  inch  ;  for  the  density  being  directly 
as  the  pressure,  we  have  30  in. :  0*56  in. 
:  :  257-218  grs. :  4-801  grs.,  which  is  the 
weight  required. 

Having  tound  the  weight  of  a  cubic  foot 
of  vapor  under  a  pressure  of  0-56  of  an 
inch,  and  at  the  temperature  212°,  we 
may  find  its  weight  under  the  same  pres- 
sure at  any  other  temperature,  suppose 
60°.  It  is  ascertained  by  experiment  that 
all  aeriform  bodies,  whether  vapors  or 
gases,  expand  the  l-480th  part  of  their 
volume  for  every  accession  of  tempera- 
ture equivalent  to  one  degree  of  Fahren- 
heit's scale  ;  therefore,  reckoning  a  vol- 
ume of  gas  at  32°  as  unity,  its  vol- 
ume at  60°  is  to  its  volume  at  212°  as 
1  +  ffi  is  to  1  +  £f  <> ;  or  as  1-058  :  1-375 ; 
and  the  density  and  weight  being  in- 
versely as  the  volume,  we  have 

1-058  : 1-375  : :  4-801  grs.    6-222  grs. 


hyg] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


251 


for  the  weight  of  a  cubic  foot  of  vapor 
at  temperature  60°,  and  under  a  pres- 
sure of  0-56  of  an  inch  of  the  mercurial 
column. 

The  following  table,  abridged  from 
DanieWs  Meteorological  Essays,  shows  the 
force  of  tension,  weight,  and  expa#ion 
of  aqueous  vapor,  at  different  tempera- 
tures, on  Fahrenheit's  scale. 


Temp. 

Force. 

Weight  of  a  cubic 
foot. 

Expansion. 

0 

•068 

•S56 

•9334 

5 

•0S3 

1-034 

•9438 

10 

•09S 

1-208 

•9542 

15 

•119 

1-451 

•9646 

20 

•140 

1-688 

•9750 

25 

•170 

2-028 

•9S55 

30 

•200 

2-361 

•9959 

85 

•240 

2.805 

1-0063 

40 

•280 

3-239 

1-0167 

45 

•340 

3-S93 

1-0271 

50 

•400 

4535 

1-0375 

55 

•476 

5-342 

1-0479 

60 

•560 

6-222 

1-0583 

65 

•657 

7-230 

1-0687 

70 

•770 

8-392 

1-0791 

75 

•906 

9780 

1-0895 

80 

1-060 

11-333 

1-0999 

85 

1-235 

13-081 

1-1003 

90 

1430 

15-005 

1-1107 

95 

1-636 

17-009 

1-1211 

212 

30-000 

257-218 

20-6005 

Having  thus  explained  the  principle  of 
the  common  hygrometer,  we  will  now  de- 
scribe one  or  two  of  the  forms  under 
which  it  has  been  most  frequently  con- 
structed. Daniell's  hygrometer  consists 
of  two  thin  glass  balls  orl4  inch  diameter, 
connected  together  by  a  tube  having  a  bore 
about  Jth  of  an  inch.  The  tube  is  bent 
at  right  angles  over  the  two  balls,  and 
the  arm  contains  a  small  thermometer 
whose  bulb,  which  should  be  of  a  length- 
ened form,  descends  into  the  ball.  This 
ball,  having  been  about  two  thirds  filled 
with  ether,  is  heated  over  a  lamp  till  the 
fluid  boils,  and  the  vapor  issues  from  the 
capillary  tube  which  terminates  the  ball. 
The  vapor  having  expelled  the  air  from 
both  balls,  the  capillary  tube  is  hermeti- 
cally closed  by  the  flame  of  a  lamp.  The 
other  baJl  is  to  be  covered  with  a  piece  of 
muslin.  The  stand  is  of  brass,  and  the 
transverse  socket  is  made  to  hold  the 
glass  tube  in  the  manner  of  a  spring,  al- 
lowing it  to  turn  and  be  taken  out  with 
little  difficulty.  A  small  thermometer  is 
inserted  into  "the  pillar  of  the  stand.  The 
manner  of  using  the  instrument  is  this  : 
after  having  driven  out  all  the  ether  into 
the  ball  by  the  heat  of  the  hand,  it  is  to 


be  placed  at  an  cpen  window,  or  out  of 
doors,  with  the  ball  so  situated  that  the 
surface  of  the  liquid  may  be  on  a  level 
with  the  eye  of  the  observer.  A  little 
ether  is  then  to  be  dropped  on  the  cov- 
ered ball.  Evaporation  immediately  takes 
place,  which  producing  cold  upon  the 
covered  ball  causes  a  rapid  continuous 
condensation  of  the  ethereal  vapor  in 
the  interior  of  the  instrument.  The  con- 
sequent evaporation  from  the  included 
ether  produces  a  depression  of  tempera- 
ture in  the  ball,  the  degree  of  which  is 
measured  by  the  thermometer.  This  ac- 
tion is  almost  instantaneous,  and  the 
thermometer  begins  to  fall  in  two  seconds 
after  the  ether  has  been  dropped.  A  de- 
pression of  30  to  40  degrees  is  easily  pro- 
duced, and  the  ether  is  sometimes  ob- 
served to  boil  and  the  thermometer  to  be 
driven  "below  zero  of  Fahrenheit's  scale. 
The  artificial  cold  thus  produced  causes  a 
condensation  of  the  atmospheric  vapor  up- 
on the  uncovered  ball,  which  first  makes, 
its  appearance  in  a  thin  ring  of  dew  co- 
incident with  the  surface  of  the  ether. 
The  degree  at  which  this  takes  place 
must  be  carefully  noted.  In  very  damp 
or  windy  weather  the  ether  should  be 
very  slowly  dropped  upon  the  ball,  oth- 
erwise the  descent  of  the  thermometer 
will  be  so  rapid  as  to  render  it  extremely 
difficult  to  be  certain  of  the  degree.  In 
dry  weather,  on  the  contrary,  the  ball  re- 
quires to  be  well  wetted  more  than  once, 
to  produce  the  requisite  degree  of  cold. 

The  instrument  which  has  now  been 
described  is  extremely  beautiful  in  prin- 
ciple ;  but  it  may  be  doubted  whether, 
even  when  the  greatest  caution  is  ob- 
served, the  temperature  which  it  indi- 
cates is  precisely  that  at  which  the  depo- 
sition of  dew  takes  place.  The  deposi- 
tion first  occurs  in  a  narrow  ring  on  a 
level  with  the  surface  of  the  etherln  tha 
ball  h,  thereby  indicating  that  the  ethei 
is  colder  at  tlie  surface  than  a  little  undei 
it.  But  if  the  temperature  is  not  uniform 
throughout  the  ball,  it  is  evident  that 
only  a  small  part  of  the  bulb  of  the  ther- 
mometer can  be  placed  in  the  point  where 
the  greatest  cold  exists  :  consequently 
the  temperature  indicated  by  the  ther- 
mometer will  be  greater  than  is  necessarj 
for  producing  the  deposition  of  moisture  ' 
in  other  words  the  dew  point  will  be  given 
too  high. 

Various  attempts  have  been  made  tc 
obviate  the  defects  of  Daniell's  hygrome- 
ter, but  hitherto  without  much  success. 
The  apparatus  proposed  by  Pouillet  may 
be  described  as  follows  :  A  small  cup  C 


258 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[iNO 


C,  formed  of  gold,  and  extremely  thin,  is 
fixed  to  a  little  collar  of  ivory  B  B,  sup- 
ported on  a  stand.  The  stem  of  an  in- 
verted thermometer  T  T  de- 
scends through  a  perforation  in 
the  bottom  of  the  cup,  and  is 
fitted  closely  into  it  and  sealed, 
the  ball  of  the  thermometer 
being  placed  at  the  centre  of 
the  cup.  In  order  to  prevent 
the  mercury  from  separating, 
a  small  portion  of  the  air  is 
left  in  the  stem.  When  an  ob- 
servation is  to  be  made,  sul- 
phuric ether  is  poured  into  the 
cup  ;  and  in  consequence  of 
the  rapid  evaporation  which 
takes  place,  a  considerable  de- 
gree of  cold  is  produced,  and 
i  deposition  takes  place  on  the 
outside  of  the  cup.  The  degree  of  the 
thermometer  at  the  instant  the  bright- 
ness of  the  metal  begins  to  be  dimmed 
gives  the  dew  point.  The  correctness  of 
the  indication  depends  on  the  identity  of 
temperature  of  the  ether,  the  metal  of 
ttvB  cup,  and  the  thermometer.  Bright 
fcOid  is* found  to  answer  the  purpose  bet- 
ter than  any  other  metal. 

As  the  hygrometer  is  one  of  the  prin- 
cipal instruments  in  meteorological  re- 
searches, its  theory  and  the  best  form  of 
its  construction  have  been  the  subject  of 
frequent  discussion  in  the  various  scien- 
tific journals. 

HYGROMETRIC.  This  term  is  com- 
monly applied  to  substances  which  readi- 
lv  become  moist  and  dry  with  correspon- 
ding changes  in  the  state  of  the  atmos- 
phere, or  which  readily  absorb  and  retain 
moisture.  Sea-weed,  several  saline  sub- 
stances, porous  clays,  potash  and  its  car- 
bonate, chloride  of  calcium,  sulphuric 
acid,  are  in  this  sense  of  the  term  said 
to  be  hygrometric. 

HYGROMETRIC  REGISTER.  Atone 
of  Lord  Rosse's  recent  scientific  soirees, 
in  London,  Mr.  Appold  exhibited  his  cu- 
rious Register  Hygrometer  for  keeping 
the  atmosphere  of  the  house  at  one  regu- 
lar moisture.  The  instrument  with  a  va- 
riation at  one  degree  in  the  moisture  of 
the  atmosphere  opens  a  valve  capable  of 
supplying  ten  quarts  of  water  per  hour ; 
delivering  it  to  pipes  covered  with  blot- 
ting paper  heated  by  a  gas  stove,  by 
which  the  water  is  evaporated  until  the 
atmosphere  is  sufficiently  saturated  and 
the  valve  thereby  closed.  A  lead  pencil 
is  attached  to  register  the  distance  the 
hygrometer  travels  ;  and  thus  a  sheet  of 
paper  moved  by  clock-work  shows  the 


difference  between  the  wet  and  dry  bulbs 
of  the  thermometer  at  any  period  of  time. 

HYPOSULPHITE  OF  SODA.  This 
salt,  so  extensively  used  in  the  practice 
of  Vaquerrotyging,  may  be  easily  pre- 
pared in  quantities  by  the  following  pro- 
cess—Mix one  pound  of  finely  pulverized 
ignited  carbonate  of  soda  with  ten  ounces 
of  flowers  of  sulphur,  and  heat  the  mix- 
ture slowly  in  a  porcelain  dish  till  the 
sulphur  melts.  Stir  the  fused  mass,  so 
as  to  expose  all  its  parts  freely  to  the 
atmosphere,  whereby  it  passes  from  the 
state  of  a  sulphuret,  by  the  absorption  of 
atmospherical  oxygen,  into  that  of  a  sul- 
phite, with  the  phenomenon  of  very 
slight  incandescence.  Dissolve  in  water, 
filter  the  solution,  and  boil  it  immediate- 
ly along  with  flowers  of  sulphur.  The 
filtered  concentrated  saline  liquid  will 
afford,  on  cooling,  a  large  quantity  of 
pure  and  beautiful  crystals  of  hyposul- 
phite of  soda. 

IMPERMEABLE,  is  the  epithet  given 
to  any  kind  of  textile  fabric,  rendered 
water-proof  by  one  or  other  of  the  follow- 
ing substances : — 

1.  Linseed  oil  to  which  a  drying  quali- 
ty has  been  communicated  by  boiling 
with  litharge  or  sugar  of  lead,  &c. 

2.  The  same  oil  holding  in  solution  a 
little  caoutchouc. 

3.  A  varnish  made  by  dissolving  caout- 
chouc in  rectified  petroleum  or  naptha, 
applied  between  two  surfaces  of  cloth,  as 
described  under  Mackintosh's  patent. 
See  Caoutchouc. 

4.  Vegetable  or  mineral  pitch,  applied 
hot  with  a  brush,  as  in  making  tarpawl- 
ing  for  covering  goods  in  ships. 

5.  A  solution  of  soap  worked  into 
cloth,  and  decomposed  in  it  by  the  action 
of  a  solution  of  alum;  whence  results  a 
mixture  of  acid  fats  and  alumina,  which 
insinuates  itself  among  all  the  woolly  fila- 
ments, fills  their  interstices,  and  prevents 
the  passage  of  water. 

6.  A  solution  of  glue  or  isinglass,  in- 
troduced into  a  stuff,  and  then  acted 
upon  by  a  solution  of  galls  or  tannin 
wlien  an  insoluble  leather  is  deposited  in 
the  stuff. 

INCOMBUSTIBLE  CLOTH  is'a  tissue 
of  the  fibrous  mineral  called  amianthus 
or  asbestos.  This  is  too  rare  to  form  the 
object  of  any  considerable  manufacture. 
Cotton  and  linen  cloth  may  be  best  ren- 
dered incapable  of  taking  fire,  or  burning 
with  flame,  by  being  imbued  with  a  solu- 
tion of  sal  ammoniac  or  phosphate  of 
magnesia. 

INCUBATION,  ARTIFICIAL.     The 


INC] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


259 


Egyptians  have  from  time  immemorial 
been  accustomed  to  hatch  eggs  by  artifi- 
cial warmth,  without  the  aid  of  hens,  in 
peculiar  stoves,  called  Mammals.  The 
inhabitants  of  the  village  Berme  still 
travel  through  the  most  distant  pro- 
vinces of  Egypt  at  certain  seasons  of  the 
year,  with  a  portable  furnace,  heated  by 
a  lamp,  and  either  hatch  chickens  for 
sale,  or  undertake  to  hatch  the  eggs  be- 
longing to  the  natives  at  a  certain  rate 
per  dozen.  M.  de  Reaumur  published  in 
France,  about  a  century  ago,  some  inge- 
nious observations  upon  this  subject ; 
but  M.  Bonnemain  was  the  first  person 
who  studied  with  due  attention  all  the 
circumstances  of  artificial  incubation,  and 
mounted  the  process  successfully  upon 
the  commercial  scale.  So  far  back  as 
1777  he  communicated  to  the  Academy 
of  Sciences  an  interesting  fact,  which  he 
had  noticed,  upon  the  mechanism  em- 
ployed by  chicks  to  break  their  shells; 
and  for  some  time  prior  to  the  French 
revolution  he  furnished  the  Parisian  mar- 
ket with  excellent  poultry  at  a  period  of 
the  year  when  farmers  had  ceased  to 
supply  it.  His  establishment  was  ruined 
at  that  disastrous  era,  and  no  other  has 
ever  since  been  constructed  or  conducted 
with  similar  care.  There  can  be  no  doubt 
however  of  the  practicability  and  profit- 
ableness of  the  scheme,  when  judiciously 
managed.  Some  imitations  of  his  plans 
have  been  made  in  England,  but  how  far 
they  have  succeeded,  in  an  economical 
point  of  view,  it  is  difficult  to  determine. 
His  apparatus  derives  peculiar  interest 
from  the  fact  that  it  was  founded  upon 
the  principle  of  the  circulation  of  hot 
water,  by  the  intestine  motions  of  its 
particles,  in  a  returning  series  of  con- 
nected pipes  ;  a  subject  afterwards  illus- 
trated in  the  experimental  researches  of 
Count  Rumford.  It  has  of  late  years  been 
introduced  as  a  novelty,  and  applied  to 
warm  the  apartments  of  many  public 
and  private  buildings.  They  were  then 
publicly  exhibited  at  his  residence  in 
Paris,  and  were  afterwards  communicated 
to  the  world  at  large  in  the  interesting 
article  of  the  Dictionnaire  Technologique, 
entitled  Incubation  Artificielle. 

The  apparatus  of  M.  Bonnemain  con- 
sisted, 1.  of  a  boiler  and  pipes  for  the 
circulation  of  water ;  2.  of  a  regulator 
calculated  to  maintain  an  equable  temper- 
ature; 3.  of  a  stove-apartment,  heated 
constantly  to  the  degree  best  fitted  for 
incubation,  which  he  called  the  hatcli- 
ing  pitch.  He  attached  to  one  side  a 
po'msimere  or  chick-room,  for  cherishing 


the  chickens  during  a  few  days  after  in 
cubation. 

The  boiler  is  represented  in  vertical 
section.  It  is  composed  of  a  double  cyl- 
inder of  copper  or  cast-iron,  1 1,  having  a 
grate,  I  (see  plan),  an  ashpit  at  d.  The 
water  occupies 
the  shaded 
J  ,  I  <p51  D  space,  c,  c.  A, 
— I  "J— X\  g,  g,  e,  e,  are 
five  vertical 
flues,  for  con- 
ducting the 
burnt  air  and 
smoke,  which 
first  rise  in  the 
two  exterior 
flues,  <?,  e}  then 
descend  in  the 
two  adjoining 
flues  g,g,  and  fi- 
nally re-mount 
through  the 
passages  i,  i, 
in  the  central  flue  h.  During  this  up- 
wards and  downwards  circulation,  as 
shown  by  the  arrows  in  the  section,  the 
products  of  combustion  are  made  to  im- 
part nearly  the  whole  of  their  heat  to  the 
water  by  which  they  are  surrounded.  At 
the  commencement,  some  burning  paper 
or  wood  shavings  are  inserted  at  the  ori- 
fice m,  to  establish  a  draught  in  this  cir- 
cuitous chimney.  The  air  is  admitted 
into  the  ashpit  at  the  side,  in  regulated 
quantities,  through  a  small  square  door, 
moveable  round  a  rod  which  runs  hori- 
zontally along  its  middle  line.  The  swing 
valve  is  acted  upon  by  an  expanding  bar, 
which  opens  it  more  or  less,  according  to 
the  temperature  of  the  stove  apartment 
in  which  the  eggs  are  placed. 

d  is  the  upper  orifice  of  the  boiler,  by 
which  the  hotter  and  consequently  lighter 
particles  of  the  water  continually  ascend, 
and  are  replaced  by  the  cooled  particles, 
which  enter  the  boiler  near  its  bottom. 

When  it  is  wished  to  hatch  eggs  with 
this  apparatus,  the  fire  is  kindled,  and 
when  the  temperature  is  100°,  the  eggs 
arc  introduced  :  only  one  twentieth  of  the 
whole  number  on  the  first  day ;  next  day 
a  like  number  is  laid  in  the  trays,  and 
thus  in  succession  for  twenty  days,  so 
that  at  the  end  of  this  time  those  first 
placed  will  be  hatched,  and  daily  after- 
wards an  equal  number  of  chicks  may  be 
obtained.  While  thus  hatching,  a  little 
of  the  water  of  the  shell  is  evaporated 
and  replaced  by  air,  which  becomes  need- 
ful for  respiration.  After  the  chicks  are 
hatched,    they    are    transferred   to   the 


260 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[iND 


chick-room,  which  contains  a  small 
vessel  filled  with  millet  seed  for  the  sup- 
port of  the  chicks. 

To  supply  an  establishment  of  the  com- 
mon kind,  where  100  eggs  are  daily 
hatched,  a  dozen  hens  would  be  needed, 
and  150  eggs  must  be  placed  under  them, 
as  only  two-thirds  succeed  ;  at  this  rate 
4300  mothers  would  be  required  to  sit. 

In  China  the  process  is  different.  There 
the  hatching  house  is  a  long  shed  with 
mud  walls  and  thickly  thatched  with 
straw.  Along  the  ends  and  down  one 
side  of  the  building  are  a  number  of 
round  straw  baskets,  well  plastered  with 
mud,  to  prevent  them  from  taking  fire. 
In  the  bottom  of  each  basket  there  is  a 
tile  placed ;  or  rather  the  tile  forms  the 
bottom  of  the  basket.  Upon  this  the  fire 
acts — a  small  fireplace  being  below  each 
basket.  Upon  the  top  of  each  basket 
there  is  a  straw  cover  which  fits  closely, 
and  is  kept  shut  while  the  process  is 
going  on.  In  the  centre  of  the  shed  are 
a  number  of  large  shelves  placed  one 
above  another,  upon  which  the  eggs  are 
laid  at  a  certain  stage  of  the  process. 
When  the  eggs  are  bought  they  are  put 
into  the  baskets — the  fire  is  lighted  below 
them — and  a  uniform  heat  kept  up,  rang- 
ing from  95  to  102  degrees;  but  the 
Chinamen  regulate  the  heat  by  their  own 
feelings,  and  therefore  it  will,  of  course, 
vary  considerable.  In  four  or  five  days 
after  the  eggs  have  been  subject  to  this 
temperature,  they  are  taken  carefully  out, 
one  by  one,  to  a  door,  in  which  a  number 
of  holes  have  been  bored  nearly  the  size 
of  the  eggs ;  they  are  then  held  against 
these  holes,  and  the  Chinamen  look 
through  them,  and  are  able  to  tell  whether 
they  are  good  or  not.  If  good,  they  are 
taken  back,  and  replaced  in  their  former 

Suarters ;  if  bad,  they  are,  of  course,  ex- 
uded. In  nine  or  ten  days  after  this — 
that  is,  about  fourteen  days  from  com- 
mencement— the  eggs  are  taken  from  the 
basket,  and  spread  out  on  the  shelves. 
Here  no  fire-heat  is  applied,  but  they  are 
covered  over  with  cotton,  and  a  kind  of 
blanket,  under  which  they  remain  about 
fourteen  days  more,  when  the  young 
ducks  burst  their  shells,  and  the  shed 
teems  with  life.  These  shelves  are  large 
and  capable  of  holding  many  thousands 
of  cgg»;   and  when  the  hatching  takes 

?lace,  the  sight  is  not  a  little  curious, 
'he  natives  who  rear  the  young  duck  in 
the  surrounding  country  know  exactly 
the  day  when  it  will  be  ready  for  removal ; 
and  in  two  days  after  the  shell  is  burst, 


the  whole  of  the  little  creatures  are  sold 
and  conveyed  to  their  new  quarters. 

INDIGO.  From  the  differences  which 
exist  in  the  nature  and  culture  of  the 
indigofera,  and  of  its  treatment  by  the 
manufacturer,  the  product,  indigo,  as 
found  in  commerce,  differs  remarkably 
in  quality  and  chemical  composition. 
Besides  the  impurities  accidentally  pre- 
sent, from  a  bad  season,  want  of  skill  or 
care,  the  purest  commercial  indigo  con- 
sists of  no  less  than  five  constituents— 1. 
Indigo-blue,  a  very  singular  vegetable 
compound  of  carbon,  hydrogen,  and  oxy- 
gen, with  about  ten  per  cent,  of  azote  ;  2. 
Indigo-gluten,  a  yellow,  or  brownish- 
yellow  varnish,  which  differs  from  wheat- 
gluten  by  its  solubility  in  water.  It  has 
the  taste  of  osmazome,  or  of  beef-soup, 
melts  when  heated,  burns  with  flame, 
and  affords  an  empyreumatic  oil  along 
with  ammonia  by  distillation ;  3.  Indigo- 
brown.  This  constituent  is  more  abundant 
than  the  preceding.  It  is  extracted  by  a 
concentrated  water  of  potash,  made  to 
act  on  powdered  indigo,  previously  di- 
gested in  dilute  sulphuric  acid.  Chev 
reuil's  indigo-green  seems  to  have  con- 
sisted of  this  substance,  mixed  with  some 
alkaline  matter,  and  indigo-blue  ;  4.  In- 
digo-red. This  is  readily  dissolved  by 
boiling  alcohol  out  of  indigo  previously 
subjected  to  the  action  of  an  acid  or  alka- 
line menstruum.  The  alcohol  acquires  a 
beautiful  red  tinge,  and  leaves  by  its 
evaporation  the  red  principle  in  the  form 
of  a  blackish-brown  varnish ;  5.  Phos- 
phate of  lime.  Dr.  Ure  found  the  bone 
Shosphate  in  notable  quantity  in  some 
ne  indigo,  constituting  another  feature 
of  resemblance  between  this  vegetable 
and  animal  products.  Hence,  also,  the 
charcoal  of  indigo  is  most  difficult  of  in- 
cineration, and  requires,  for  perfect  com- 
bustion, in  some  cases,  the  deflagratory 
powers  of  nitric  acid. 

The  species  of  indigofera  are  legumin- 
ous plants,  herbaceous  or  shrubby.  They 
are  veiy  numerous  in  the  equatorial  re- 
gions of  the  globe.   The  /.  tinctoria  is  the 
species  most  abundantly  cultivated.    The 
plant  requires  a  rich,  light  soil,   and  a 
warm    exposure.      It  succeeds  best   on 
newly-cleared  lands,  on  account  of  their 
moisture ;  it  requires  protection  against 
!  high  winds,  and  needs  irrigation  in  times 
|  of  drought.      The  ground,   after  being 
properly  prepared   tor  the  reception  of 
!  the  seed  by  ploughing,  is  sown  pretty 
|  thickly,   the  time  of  sowing   being  so 
I  chosen  that  rain  may  fall  upoD  the  plant 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


261 


as  soon  as    it    shows  itself  above  the 


X 


invigorated,  but  cleansed  from  innumer 
able  insects 

As  the  plant  approaches  to  maturity, 
the  leaves  undergo  a  sudden  change  in 
color,  from  a  light  to  a  dark  green.  As 
soon  as  this  change  is  observed,  the 
brunches  are  severed  from  the  parent 
stem  early  in  the  morning,  and  spread 
out  in  the  sun  till  the  afternoon,  by  which 
time  they  become  sufficiently  dry  to  be 
beaten  from  the  branches  by  a  stick.  The 
leaves,  so  separated,  are  housed  in  ware- 
houses, closely  packed  and  well  trodden 
down  by  natives. 

The  plants,  from  which  leaves  have 
been  severed,  send  forth  a  new  crop, 
which  is  gathered,  when  mature,  like  the 
first.  The  cuttings,  in  a  favorable  sea- 
son, are  repeated  three  or  four  times, 
after  which  the  ground  is  ploughed  up 
for  another  sowing ;  but  each  successive 
growth  of  the  branches  produces  an  in- 
creased deterioration  of  the  qualities  of 
the  leaves,  so  that  one  part  of  the  leaves 
of  the  first  cutting  yields  as  much  indigo 
as  two  parts  of  the  third  crop.  The  dried 
leaves  are  not  immediately  used,  but  are 
kept  packed  for  one  month,  during  which 
time  they  suffer  a  material  change,  which 
is  indicated  by  their  having  passed  to  a 
light  lead  color.  By  additional  keeping, 
the  lead  color  gradually  darkens,  until  it 
becomes  black.  The  maximum  quantity 
of  indigo  is  to  be  obtained  when  the  lead 
color  is  attended  with  a  loss  in  the  quan- 
tity of  the  indigo.  The  dried  leaves, 
after  having  suffered  the  change  of  color, 
are  transferred  to  the  steeping-vat  (an 
uncovered  reservoir,  30  feet  square,  and 
26  inches  deep,  constructed  of  brick,  and 
lined  with  stucco,)  where  they  are 
mingled  with  water,  in  the  proportion 
of  about  one  volume  of  leaves  to  six  of 
water,  and  allowed  to  remain  two  hours. 

The  great  affinity  of  indigo  for  oxygen 
is  very  manifest,  in  the  quick  change  of 
the  color  of  the  leaves  which  float  on  the 
surface,  and  are  exposed  to  the  action  of 
the  atmosphere,  to  a  blackish  blue,  when 
contrasted  with  those  below,  which  re- 
main unchanged.  On  this  account,  the 
vat  is  frequently  stirred,  so  that  the 
floating  leaves  may  be  immersed.  After 
two  hours'  infusion,  the  water,  which, 
from  the  solution  of  imperfectly-oxygen- 
ized indigo,  has  acquired  a  fine  green 
color,  is  allowed  to  run  off  from  the 
leaves,  through  strainers,  into  the  beat- 
ing-vat, where  it  is  agitated  by  the  pad- 
dles of  10  or  12  natives  for  about  two 


hours,  during  which  time  the  fine  green 
liquor  gradually  darkens  to  a  blackish- 
blue.  At  this  time,  lime-water  is  thrown 
into  the  vat,  and  thoroughly  agitated 
with  the  whole  mass  of  fluid.  The  mass 
is  then  left  to  subside  for  the  space  of 
three  hours,  when  the  supernatant  liquid, 
which  is  of  a  fine  bright  Madeira  color,  is 
withdrawn,  by  orifices  in  the  vat  at  dif- 
ferent heights.  The  indigo  is  then  re- 
moved to  the  covered  part  of  the  manu- 
factory, where  it  is  put  on  a  straining- 
cloth,  and  allowed  to  drain  throughout 
the  night.  On  the  following  morning  it 
is  transferred  to  a  copper  boiler,  where  it 
is  mingled  with  a  quantity  of  water,  and 
raised  to  ebullition.  The  contents  of  the 
copper  are  retaken  to  the  strainers,  and 
the  drained  indigo  is  then  divided  into 
small  portions,  and  each  portion  well 
worked  by  the  hands  of  the  natives,  in 
order  to  free  it  from  air-bubbles.  It  is 
then  carried  to  the  pressing-boxes,  which 
are  usually  square,  and  of  sufficient  depth 
to  leave  the  cake  about  two  inches  and  a 
quarter  in  thickness.  By  means  of  a 
powerful  screw,  the  water  is  separated 
trom  the  indigo ;  the  cakes  are  gradually 
dried  in  the  shade,  and  thus  rendered  fit 
for  exportation. 

When  indigo,  suspended  in  water,  is 
brought  into  contact  with  certain  deox- 
idizing agents,  it  is  deprived  of  a  part  of 
its  oxygen,  becomes  green,  and  is  ren- 
dered soluble  in  water,  and  still  more  so 
in  the  alkalies.  It  recovers  its  former 
color,  however,  on  exposure  to  the  air,  by 
again  absorbing  oxygen  of  l-7th  or  l-8th 
0? the  whole  weight  of  the  resulting  in- 
digo. Its  deoxidizement  is  effected  either 
by  allowing  it  to  ferment  along  with  bran, 
or  other  vegetable  matter,  or  by  decom- 
posing in  contact  with  it  the  protosul- 
phate  of  iron,  by  the  addition  of  lime. 

Substances  dyed  by  deoxidized  indigo 
receive  a  green  tint  at  first,  which  be- 
comes blue  by  exposure  to  the  air.  This 
is  the  usual  method  of  coloring  cloths  by 
means  of  indigo,  which,  when  fully  oxi- 
dized, affords  a  permanent  dye,  not  re- 
movable by  soap  or  by  acids. 

Indigo,  purified  by  sublimation,  is 
composed  ot  73-26  carbon,  13-81  nitrogen, 
10-43  oxygen,  and  2-5  hydrogen. 

Employment  of  indigo  in  dyeing. — As 
indigo  is  insoluble  in  water,  and  as  it  can 
penetrate  the  fibres  of  wool,  cotton,  silk, 
and  flax,  only  when  in  a  state  of  solution, 
the  dyer  must  study  to  bring  it  into  this 
condition  in  the  most  complete  and  eco- 
nomical manner.  This  is  effected  either 
by  exposing  it  to  the  action  of  bodies 


262 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


1> 


which  have  an  affinity  for  oxygen  superior 
to  its  own,  such  as  certain  metals  and 
metallic  oxydes,  or  by  mixing  it  with  fer- 
menting matters,  or,  finally,  by  dissolving 
it  in  a  strong  acid,  such  as  the  sulphuric. 
The  second  of  the  above  methods  is  called 
the  warm  hue,  or  pastel  vat ;  and  being 
the  most  intricate,  we  shall  begin  with 
it. 

Before  the  substance  indigo  was  known 
in  Europe,  woad  having  been  used  for 
dyeing  blue,  gave  the  name  of  woad  vats 
to  the  apparatus.  The  vats  are  sometimes 
made  of  copper,  at  other  times  of  iron  or 
wood,  the  last  alone  being  well  adapted 
for  the  employment  of  steam.  The  di- 
mensions are  very  variable ;  but  the  fol- 
lowing may  be  considered  as  the  average 
size :  depth,  7£  feet ;  width  below,  4 
feet ;  above,  5  feet.  The  vats  are  built  in 
such  a  way  that  the  fire  does  not  affect 
their  bottom,  but  merely  their  sides  half 
way  up ;  and  they  are  sunk  so  much 
under  the  floor  of  the  dyehouse,  that 
their  upper  half  only  is  above  it,  and  is 
surrounded  with  a  mass  of  masonry  to 
prevent  the  dissipation  of  the  heat. 
About  3  or  3s  feet  under  the  top  edge  an 
iron  ring  is  fixed,  called  the  champagne  by 
the  French,  to  which  a  net  is  attached  in 
order  to  suspend  the  stuffs  out  of  contact 
of  the  sediment  near  the  bottom. 

In  mounting  the  vat  the  following  arti- 
cles are  required:  1.  woad  prepared  by 
fermentation,  or  woad  merely  dried, 
which  is  better,  because  it  may  be  made 
to  ferment  in  the  vat,  without  the  risk  of 
becoming  putrid,  as  the  former  is  apt  to 
do ;  2.  indigo,  previously  ground  in  a 
proper  mill ;  3.  madder ;  4.  potash ;  5. 
slaked  quicklime;  6.  bran.  In  France, 
weld  is  commonly  used  instead  of  potash. 

The  vat  being  filled  with  clear  river 
water,  the  fire  is  to  be  kindled,  the  in- 
gredients introduced,  and  if  fermented 
woad  be  employed,  less  lime  is  needed 
than  with  the  merely  dried  plant.  Mean- 
while the  water  is  to  be  heated  to  the 
temperature  of  160°  Fahr.,  and  main- 
tained at  this  pitch  till  the  deoxidize- 
ment  and  solution  of  the  indigo  begin  to 
show  themselves,  which,  according  to  the 
state  of  the  constituents,  may  happen  in 
12  hours,  or  not  till  after  several  days. 
The  first  characters  of  incipient  solution 
are  blue  bubbles,  called  the  flowers, 
which  rise  upon  the  surface,  and  remain 
like  a  head  of  soap-suds  for  a  consider- 
able time  before  they  fall;  then  blue 
coppery  shining  veins  appear  with  a  like 
colored  froth.  The  hue  of  the  liquor 
now  passes  from  blue  to  green,  and  an 


ammoniacal  odor  begins  to  be  exhaled. 
Whenever  the  indigo  is  completely  dis- 
solved, an  acetic  smelling  acid  may  be 
recognised  in  the  vat,  which  neutralizes 
all  the  alkali,  and  may  occasion  even  an 
acid  excess,  which  should  be  saturated 
with  quicklime.  The  time  for  doing  this 
cannot  be  in  general  very  exactly  defined. 
When  quicklime  has  been  added  at  the 
beginning  in  sufficient  quantity,  the 
liquor  appears  of  a  pale  wine-yellow 
color,  but  if  not,  it  acquires  this  tint  on 
the  subsequent  introduction  of  the  lime. 
Experience  has  not  hitherto  decided  in 
favor  of  the  one  practice  or  the  other. 

As  soon  as  this  yellow  color  is  formed 
in  the  liquor,  and  its  surface  becomes 
blue,  the  vat  is  ready  for  the  dyer,  and 
the  more  lime  it  takes  up  without  being 
alkaline,  the  better  is  its  condition.  The 
dyeing  power  of  the  vat  may  be  kept  up 
during  six  months,  or  more,  according  to 
the  fermentable  property  of  the  woad. 
From  time  to  time,  madder  and  bran 
must  be  added  to  it,  to  revive  the  fer- 
mentation of  the  sediment,  along  with 
some  indigo  and  potash,  to  replace  what 
mav  have  been  abstracted  in  the  progress 
of  dyeing.  The  quantity  of  indigo  must 
be  proportional,  of  course,  to  the  depth 
or  lightness  of  the  tints  required. 

Cold  vats. — The  copperas  or  common  blue 
vat  is  so  named  because  the  indigo  is  re- 
duced by  means  of  the  protoxide  of  iron. 
This  salt  should  therefore  be  as  free  as 
possible  from  the  red  oxide,  and  espe- 
cially from  any  sulphate  of  copper,  which 
would  re-oxidize  the  indigo.  The  neces- 
sary ingredients  are  :  copperas  (green 
sulphate  of  iron),  newly  slaked  quick- 
lime, finely  ground  indigo,  and  water; 
to  which  sometimes  a  little  potash  or  soda 
is  added,  with  a  proportional  diminution 
of  the  lime.  The  operation  is  conducted 
in  the  following  way:  the  indigo,  well 
triturated  with  water  or  an  alkaline  ley, 
must  be  mixed  with  hot  water  in  the 
preparation,  vat,  then  the  requisite  quan- 
tity of  lime  is  added,  after  which  the  so- 
lution of  copperas  must  be  poured  in 
with  stirring.  Of  this  preparation  vat, 
such  a  portion  as  may  be  wanted  is  laded 
into  the  dyeing  vat.  For  one  pound  of 
indigo  three  pounds  of  copperas  are  ta- 
ken," and  four  pounds  of  lime  (or  1  of 
indigo,  2i  of  copperas,  and  3  of  lime). 
If  the  copperas  be  partially  peroxidized, 
somewhat  more  of  it  must  be  used. 

A  vat  cowtaining  a  considerable  excess 
of  lime  is  called  a  s?ia?-p  vat,  and  is  not 
well  adapted  for  dyeing.  A  soft  vat,  on 
the  contrary,  is  that  which  contains  too 


ind] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


2G3 


much  copperas.  In  this  case  the  preci- 
pitate is  apt  to  rise,  and  to  prevent  uni- 
formity of  tint  in  the  dyed  goods.  The 
sediment  of  the  copperas  vat  consists  of 
sulphate  of  lime,  oxide  of  iron,  lime  with 
indigo  brown,  and  lime  with  indigo  blue, 
when  too  much  quicklime  has  been  em- 
ployed. The  clear,  dark  wine  yellow 
fluid  contains  indigo  blue  in  a  reduced 
state,  and  indigo  red,  both  combined 
with  lime  and  with  the  gluten  of  indigo 
dissolved.  After  using  it  for  some  time 
the  vat  should  be  refreshed  or  fed  with 
copperas  and  lime,  upon  which  occasion 
the  sediment  must  first  be  stirred  up, 
and  then  allowed  time  to  settle  again  and 
become  clear.  For  obtaining  a  series  of 
blue  tints,  a  series  of  vats  of  different 
strengths  is  required. 

Linen  and  cotton  yarn,  before  being 
dyed,  should  be  boiled  with  a  weak  alka- 
line ley,  then  put  upon  frames  or  tied  up 
in  hanks,  and  after  removing  the  froth 
from  the  vat,  plunged  into  and  moved 
gently  through  it.  For  pale-blues,  an 
old,  nearly  exhausted  vat  is  used ;  but 
for  deep  ones,  a  fresh,  nearly  saturated 
vat.  Cloth  is  stretched  upon  a  proper 
square  dipping-frame  made  of  wood,  or 
preferably  of  iron,  furnished  with  sharp 
nooks  or  points  of  attachment.  These 
frames  are  suspended  by  cords  over  a 
pulley,  and  thus  immersed  and  lifted  out 
alternately  at  proper  intervals.  In  the 
course  of  8  or  10  minutes,  the  cloth  is 
sufficiently  saturated  with  the  solution 
of  indigo,  after  which  it  is  raised  and 
suspended  so  as  to  drain  into  the  vat. 
The  number  of  dippings  determines  the 
depth  of  the  shade ;  after  the  last,  the 
goods  are  allowed  to  dry,  taken  off  the 
frame,  plunged  into  a  sour  bath  of  very 
dilute  sulphuric  or  muriatic  acid,  to  re- 
move the  adhering  lime,  and  then  well 
rinsed  in  running  water. 

The  mode  of  making  the  China  blue- 
dye  has  been  described  under  Calico 
Printing. 

A  blue  dye  may  likewise  be  given  by 
a  solution  of  indigo  in  sulphuric  acid. 
This  process  was  discovered  by  Barth,  at 
Grossenhayn,  in  Saxony,  about  the  year 
1740,  and  is  hence  called  the  Saxon  blue- 
dye.  The  chemical  nature  of  this  pro- 
cess has  been  already  fully  explained.  If 
the  smoking  sulphuric  acid  be  employed, 
from  4  to  5  parts  are  sufficient  for  1  of 
indigo ;  but  if  oil  of  vitriol,  from  7  to  8 
parts.  The  acid  is  to  be  poured  into  an 
earthenware  pan,  which  in  summer  must 
be  placed  in  a  tub  of  cold  water,  to  pre- 
vent it  getting  hot,  and  the  indigo,  in 


fine  power,  is  to  be  added,  with  careful 
stirring,  in  small  successive  portions.  If 
it  becomes  heated,  a  part  of  the  indigo  is 
decomposed,  with  the  disengagement  of 
sulphurous  acid  gas,  and  indigo-green  is 
produced.  Whenever  all  the  indigo  has 
been  dissolved,  the  vessel  must  be  cover- 
ed up,  allowed  to  stand  for  48  hours,  and 
then  diluted  with  twice  its  weight  of 
clear  river  water. 

The  acidulated  mass  has  a  black  color, 
is  opaque,  thick,  attracts  water  from  the 
air,  ana  is  called  indigo  composition,  or 
chemic-blue.  It  must  be  prepared  before- 
hand, and  kept  in  store.  In  this  solu- 
tion, besides  the  cerulin,  there  are  also 
indigo-red,  indigo-brown,  and  gluten, 
by  which  admixture  the  pure  blue  of  the 
dye  is  rendered  foul,  assuming  a  brown 
or  a  green  cast.  To  remove  these  con- 
taminations, wool  is  had  recourse  to. 
This  is  plunged  into  the  indigo  previ- 
ously diffused  through  a  considerable 
body  of  water,  brought  to  a  boiling  heat 
in  a  copper  kettle,  and  then  allowed  to 
macerate  as  it  cools  for  24  hours.  The 
wool  takes  a  dark-blue  dye  by  absorbing 
the  indigo-blue  sulphate  and  hyposul- 
phite, while  at  the  same  time  the  liquor 
becomes  greenish-blue  ;  and  if  the  wool 
be  left  longer  immersed,  it  becomes  of  a 
dirty-yellow.  It  must  therefore  be  taken 
out,  drained,  washed  in  running  water 
till  this  runs  off  colorless,  and  without 
an  acid  taste.  It  must  next  be  put  into 
a  copper  full  of  water,  containing  one  or 
two  per  cent,  of  carbonate  of  potash, 
soda,  or  ammonia  (to  about  one-third 
the  weight  of  the  indigo),  and  subjected 
to  a  boiling  heat  for  a  quarter  of  an  hour. 
The  blue  salts  forsake  the  wool,  leaving 
it  of  a  dirty  red-brown,  and  dye  the  wa- 
ter blue.  The  wool  is  in  fact  dyed  with 
the  incligo-rcd,  which  is  hardly  soluble 
in  alkali.  The  blue  liquor  may  now  be 
employed  as  a  fine  dye,  possessed  of  su- 
perior tone  and  lustre.  It  is  called  dis- 
tilled blue  and  soluble  blue.  Sulphuric 
acid  throws  down  from  it  the  small  quan- 
tity of  indigo-red  which  had  been  held 
in  solution  by  the  alkali. 

When  wool  is  to  be  dyed  with  this 
sulphate  of  indigo-blue,  it  must  be  first 
boiled  in  alum,  then  treated  with  blue 
liquor,  and  thus  several  times  alternate- 
ly, in  order  to  produce  a  uniform  blue 
color.  Too  long  continuance  of  boiling 
is  injurious  to  the  beauty  of  the  dye.  In 
this  operation  the  woollen  fibres  get  im- 
pregnated with  the  indigo-blue  sulphate 
of  alumina. 

With  sulphate  of  indigo,  not  only  blues 


264 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


INK 


of  every  shade  are  dyed,  but  also  green, 
olive,  gray,  as  also  a' fast  ground  to  log- 
wood-blues ;  for  the  latter  purpose  the 
preparatory  boil  is  given  with  alum,  tar- 
tar, sulphates  of  copper  and  iron,  and 
the  blue  solution  ;  after  which  the  goods 
are  dyed  up  with  a  logwood  bath  con- 
taining a  little  potash. 

INK.  The  colored  liquid  used  for 
writing,  is  made  usually  by  the  action  of 
the  tannin  of  vegetable' substances  upon 
salts  of  iron.  In  the  case  of  black  ink, 
nut-galls,  sulphate  of  iron,  and  gum,  are 
the  only  substances  necessary  :  others 
being  added  to  modify  the  shade,  or 
diminish  the  cost.  Those  which  contain 
most  gallic  acid  or  tannin  acid  are  most 
valuable,  and  the  reverse.  To  make  12 
gallons  of  ink,  Dr.  Ure  directs  to  take 

12  lbs.  of  Nut-galls. 

5  lbs.  of  Green  Sulphate  Iron, 

5  lbs.  of  Gum  Senegal, 
12  gallons  of  Water. 

The  nut-galls  and  water  are  put  into  a 
copper  and  well  boiled,  replacing  the 
water  lost :  it  is  then  poured  into  a  tub, 
let  to  settle,  and  strained.  The  gum  is 
then  dissolved,  strained,  and  added  to 
the  gall  liquor.  The  copperas  is  also  dis- 
solved and  added,  when  the  whole  be- 
comes gradually  black.  It  should  be 
bottled  before  it  attains  its  full  black- 
ness. A  few  bruised  cloves  added  in, 
prevents  mouldiness.  Sumach,  logwood, 
and  oak-bark,  are  often  used  instead  of 
galls,  or  in  addition  to  it,  to  diminish 
the  cost  of  manufacture ;  but  the  ink  is 
deteriorated  by  their  use.  Logwood 
requires  less  copperas  than  galls.  The 
foregoing  ink  is  much  stronger  than  that 
commonly  sold,  and  it  may  be  diluted 
with  an  equal  quantity  of  water  to  form 
an  ink  of  similar  strength  to  that  usually 
sold.  A  good  black  ink  should  write 
pale  and  become  black  afterwards  in  the 
paper :  that  which  writes  black  at  once 
and  shines  on  the  surface  of  the  paper, 
easily  rubs  off  and  is  not  as  permanent 

Japan  ink,  as  such  is  called,  is  not 
lasting. 

Inks  are  of  almost  every  shade,  and 
generally  are  solutions  of  chemical  salts. 

Red  ink.  Take  a  strong  decoction  of 
Brazil  wood  and  a  little  gum-water,  and 
add  some  alum  with  a  few  drops  of  the 
chloride  of  tin. 

A  still  better  red  ink  is  a  decoction  of 
cochineal,  to  which  a  little  water  of  am- 
monia has  been  added :  or  an  extempo- 
raneous red  ink  may  be  made  by  rubbing 
up  carmine  in  strong  water  of  ammonia, 


diluting  the  solution  down  to  the  desired 
shade,  and  adding  mucilage. 

Green  ink.  Dissolve  distilled  verdi- 
gris is  strong  vinegar,  and  make  into  a 
proper  consistency  for  writing  with  a  so- 
lution of  gum  arabic :  or  boil  2  parts  of 
verdigris,  8  parts  of  water,  and  1  part  of 
cream  of  tartar  together  down  to  one  half, 
let  settle,  strain,  and  bottle. 

Yellow  ink.  A  little  alum  added  to 
saffron  and  water,  makes  a  very  good 
yellow  ink — thicken  with  gum :  or  boil  3 
parts  of  alum,  100  parts  of  water,  and  25 
parts  of  Persian  berries  together,  strain, 
and  add  mucilage  ;  or  dissolve  gamboge 
in  water. 

The  different  dye-stuffs  and  solutions, 
afford  inks  of  any  desired  shade. 

Mr.  I.  Deck  has  recommended  a  new 
mode  of  making  black  ink,  which  affords 
a  good  color  and  is  remarkably  cheap. 
The  process  is  this :  boil  1  part  of  log- 
wood in  100  parts  of  water  until  the 
liquor  is  pretty  strong,  and  to  one  quart 
of  it  put  in  one  quarter  of  an  ounce  of 
chromate  of  potash,  and  set  it  apart, 
shaking  it  frequently,  for  about  three 
weeks.  At  first  the  appearance  of  the 
ink  will  be  a  little  greenish,  but  after  it 
is  exposed  to  the  sun  and  air  for  some 
time,  it  gets  beautiful,  is  very  fast,  and 
does  not  injure  steel  pens. 

Ink  powder.  Blue  galls,  2  ounces  ;  gum 
arabic,  £  an  ounce;  sulphate  of  iron,  3 
ounces — all  powdered  and  well  mixed 
together. 

IndelUtle  inks.  These  used  to  have  for 
a  basis  nitrate  of  silver,  which,  in  a  strong 
solution,  thickened  with  gum  and  color- 
ed, was  laid  with  a  pen  on  the  cloth  pre- 
viously soaked  with  carbonate  of  soda — 
which" reduced  the  oxide  of  silver  in  the 
tissue  of  the  stuff.  More  recently,  the 
nitrate  of  silver  has  been  dissolved  in 
water  of  ammonia  and  laid  on  the  cloth 
without  any  further  treatment :  this  ink 
is  not  now  indelible,  its  stain  is  removed 
by  chlorine  and  water  of  ammonia,  and 
of  course  it  does  not  resist  the  bleaching- 
powder  used  in  laundries.  Fine  gold- 
powder,  rubbed  up  with  genuine  China 
ink,  resists  the  action  of  chlorine,  oxalic 
acid,  and  washing  off  with  water.  Char- 
coal, rubbed  up  with  acetic  acid  and 
thickened,  furnishes  a  very  permanent 
ink. 

The  following  indestructible  ink  has 
been  tried  and  recommended  :  shell  lac, 
2  ounces ;  borax,  1  ounce ;  distilled  or 
rain  water,  18  ounces — boil  the  whole  in 
a  closely-covered  tin  vessel,  stirring  it 
occasionally  with  a  glass  rod  or  a  small 


iod] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


265 


stick,  until  the  mixture  has  become  ho- 
mogeneous ;  filter,  when  cold,  through 
a  single  sheet  of  blotting  paper ;  mix  the 
filtered  solution,  which  will  be  about  19 
fluid  ounces,  with  1  ounce  of  mucilage 
of  gum  arabic,  prepared  by  dissolving  1 
ounce  of  water,  and  add  pulverized  in- 
digo and  lamp-black,  ad  libitum.  Boil 
the  whole  again  in  a  covered  vessel,  and 
stir  the  fluid  well  to  effect  the  complete 
solution  and  admixture  of  the  gum  ara- 
bic ;  stir  it  occasionally  while  it  is  cool- 
ing; and  after  it  has  remained  undis- 
turbed for  two  or  three  hours,  that  the 
excess  of  indigo  and  lamp-black  may 
subside,  bottle  it  for  use.  The  above 
ink,  for  documentary  purposes,  is  in- 
valuable, being,  under  all  ordinary  cir- 
cumstances, indestructible :  it  is  also  par- 
ticularly well  adapted  for  the  use  of  the 
laboratory.  Five  drops  of  kreosote  added 
to  a  pint  of  ordinary  ink  will  effectually 
prevent  its  becoming  mouldy. 

Vanadate  of  ammonia  treated  with 
galls  affords  a  good  and  permanent  black 
which  flows  freely  from  the  pen,  it  re- 
sists the  action  of  chlorine  and  is  not  ob- 
literated by  acids  or  alkalies.  Whenever 
the  metal  vanadium  will  be  found  more 
plentiful  this  combination  will  form  the 
best  ink.  Perhaps  the  Lake  Superior 
copper  may  have  its  vanadium  turned  to 
advantage' in  this  way. 

Ink  for  Lithographers. — White  soap  25 
parts,  white  wax  25  parts,  mutton  suet  6 
parts,  lamp  black  6  parts,  shellac  10  parts, 
mastic  10  parts  ;  mix  with  heat  and  pro- 
ceed as  for  lithographic  ink. 

Sympathetic  Ink. — The  best  is  a  solution 
of  muriate  of  cobalt. 

Copying  Ink. — Gum  arabic  240  grains, 
Spanish  liquorice  20  grains,  water  720 
grains,  dissolve  ;  then  add  the  solution 
gradually  in  a  mortar  to  60  grains  of 
lampblack  previously  moistened  with  a 
teaspoonful  of  sherry  ;  when  well  mixed 
strain  through  coarse  muslin. 

Saxon  Blue  Ink,  is  a  solution  of  sul- 
phate of  indigo,  used  by  dyers,  weakened 
down  to  proper  tint.  A  better  kind  of 
blue  ink  is  made  by  rubbing  together  £ 
oz.  of  best  Prussian  blue,  (th at  recently 
made  is  best),  oxalic  acid  2  drachms,  and'l 
pint  of  water  ;  filter,  when  well  mixed. 
This  has  a  beautiful  tint. 

Printer's  Ink.    See  under  that  head. 

INULINE,  is  a  substance  first  extract- 
ed from  the  root  of  the  Inula- Hellenium, 
or  Elecampane.  It  is  white  and  pulveru- 
lent like  starch ;  and  differs  from  this 
substance  chiefly  because  its  solution, 
12 


when  it  cools,  lets  fall  the  inuline  un- 
changed in  powder,  whereas  starch  re- 
mains dissolved  in  the  cold,  as  a  jelly  or 
paste. 

Inuline  is  obtained  by  boiling  the  root 
sliced  in  3  or  4  times  its  weight  of  water, 
and  setting  the  strained  decoction  aside 
till  it  cools,  when  the  pulverulent  inuline 
precipitates.  It  exists  also  in  the  roots 
of  colchicum  and  pellitory. 

IODINE,  is  one  of  the  simple  chemical 
bodies  which  was  discovered  accidentally 
in  1812,  by  M.  Courtois,  a  manufacturer 
of  saltpetre,  in  the  mother-waters  of  that 
salt.  Its  affinities  for  other  substances 
are  so  powerful  as  to  prevent  it  from  ex- 
isting in  an  insulated  state.  It  occurs 
combined  with  potassium  and  sodium  in 
many  mineral  waters,  such  as  the  brine 
spring  of  Ashby-de-la-Zouche,  and  other 
strongly  saline  springs.  This  combina- 
tion exists  sparingly  hi  sea-water,  abun- 
dantly in  many  species  of  fucus  or  sea- 
weed, and  in  the  kelp  made  from  them  ; 
in  sponges ;  in  several  marine  molluscce, 
such  as  the  doris,  the  venus,  oysters,  &c. ; 
in  several  polyparies  and  sea-plants,  as 
the  gorgonia," the  zostera  marina,  &c. ; 
particularly  in  the  mother-waters  of  the 
salt-works  upon  the  Mediterranean  sea; 
and  it  has  been  found  in  combination 
with  silver,  in  some  ores  brought  from 
the  neighborhood  of  Mexico. 

It  is  an  ingredient  in  the  salt  licks,  sa- 
line, and  brine  springs  of  this  country, 
especially  of  those  in  the  Valley  of  the 
Mississippi,  and  it  has  been  found  to  be 
a  constituent  of  coal.  It  seems  to  be  be- 
neficial to  marine  plants,  and  they  have 
the  power  of  abstracting  it  from  sea-wa- 
ter. It  is  from  these  plants  that  almost 
all  the  iodine  of  commerce  is  derived. 

Kelp,  or  the  half  vitrified  ashes  of  sea- 
weeds, prepared  by  the  inhabitants  of  the 
Western  Islands  and  the  northern  shores 
of  Scotland  and  Ireland,  is  treated  with 
water,  and  the  solution  filtered.  The  li- 
quid is  then  concentrated  by  evaporation 
until  it  is  reduced  to  a  very  small  volume, 
the  chloride  of  sodium,  carbonate  of  soda, 
chloride  of  potassium,  and  other  salts, 
being  removed  as  they  successively  crys- 
tallize. The  dark  brown  mother-liquor 
left,  contains  very  nearly  the  whole  of  the 
iodide  ;  this  is  mixed  with  sulphuric  acid 
and  peroxide  of  manganese,  and  gently 
heated  in  a  leaden  retort,  when  the  io- 
dine distils  over  and  condenses  in  the  re- 
ceiver. The  theory  of  the  operation  is 
exactly  analogous  to  that  of  the  prepara- 
tion of  chlorine  ;  it  requires  in  practice, 


266 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mo 


however,  careful  management,  otherwise 
the  impurities  present  in  the  solution  in- 
terfere with  the  general  result. 

The  manganese  is  not  really  essential ; 
the  iodide  of  potassium  or  sodium,  heated 
with  an  excess  of  sulphuric  acid  evolves 
iodine.  It  is  probable  that  this  effect  is 
due  to  a  secondary  action  between  the 
hydriodic  acid  first  produced  and  the  re- 
sidue of  the  sulphuric  acid,  in  which  both 
suffer  decomposition,  yielding  iodine, 
water,  and  sulphurous  acid. 

Iodine  crystallizes  in  plates  or  scales  of 
a  bluish  black  color  and  imperfect  metal- 
lic lustre,  resembling  that  of  plumbago  ; 
the  crystals  are  sometimes  very  large  and 
brilliant.  Its  density  is  4-948.  At  225° 
it  fuses,  and  at  347°  boils,  the  vapor  hav- 
ing an  exceedingly  beautiful  violet  color. 
It  is  slowly  volatile,  however,  at  common 
temperature,  and  exhales  an  odor  much 
resembling  that  of  chlorine.  The  density 
of  the  vapor  is  8-716.  Iodine  requires 
for  solution  about  7000  parts  of  water, 
which  nevertheless  acquires  a  brown  co- 
lor :  in  alcohol  it  is  much  more  freely  so- 
luble. Solutions  of  hydriodic  acid  and 
the  iodides  of  the  alkaline  metals  also  dis- 
solve a  large  quantity;  these  solutions 
are  not  decomposed  by  water,  which  is 
the  case  with  the  alcoholic  tincture. 

This  substance  stains  the  skin,  but  not 
permanently ;  it  has  a  very  energetic  ac- 
tion upon  the  animal  system,  and  is  much 
used  in  medicine. 

One  of  the  most  characteristic  proper- 
ties of  iodine  is  the  production  of  a 
splendid  blue  color  by  contact  with  the 
organic  principle  starch.  The  iodine  for 
this  purpose  must  be  free  or  uncombined. 
It  is  easy,  however,  to  make  the  test 
available  for  the  purpose  of  recognising 
the  presence  of  the  element  in  question 
when  a  soluble  iodide  is  suspected ;  it  is 
only  necessary  to  add  a  very  small  quan- 
tity of  chlorine-water,  when  the  iodine, 
being  displaced  from  combination,  be- 
comes capable  of  acting  upon  the  starch. 

Iodine  is  now  extensively  used  by  the 
Daguerreotypist  to  coat  the  silver 'plate 
with  so  as  to  form  a  surface  sensitive  to 
light ;  generally  the  pure  iodine  is  used 
in  the  coating,  occasionally  the  chloride  of 
iodine  is  preferred.  Iodine  is  also  used 
by  the  French  to  produce  a  blue  color 
adapted  for  dyeing  cotton  with. 

Iodine,  Chloride  of,  is  a  preparation 
used  in  daguerreotyping.  It  is  made  by 
passing  chlorine  gas  through  iodine  until 
the  whole  becomes  liquid.  Iodine  readily 
absorbs  chlorine  forming  when  the  chlo- 
rine is  in  excess  a  solid  yellow  compound, 


and  when  the  iodine  prepondeiates  a 
brown  liquid  ;  the  solid  iodide  is  decom- 
posed by  water.  The  liquid  is  not,  and  is 
that  which  is  used  in  the  arts.  It  is  a 
yellow,  oily  liquid,  of  a  suffocating  smell 
and  astringent  taste,  soluble  in  water  and 
alcohol.  It  consists  of  1  equivalent  ol 
chlorine  united  with  1  equiv.  of  iodine. 

IKIDIUM  is  a  metal  discovered  by  ' 
Descotils,  in  1803,  as  also  by  Tenant,  in 
1804 ;  and  is  so  called  because  its  differ- 
ent solutions  exhibit  all  the  colors  of  the 
rainbow.  It  occurs  only  in  the  ore  of 
platinum,  being  found  there  in  two  states ; 
1.  united  to  that  metal,  and  2.  as  alloy  of 
osmium  and  iridium,  in  the  form  of  small, 
insulated,  hard  grains.  Iridium  is  the 
most  refractory  of  all  the  metals  ;  and  ap- 
pears as  a  gray  metallic  powder.  It  is 
not  fused  by  the  flame  of  the  hydro-oxy- 
gen lamp. 

IKON.  Every  person  knows  the  man- 
ifold uses  of  this  truly  precious  metal ;  it 
is  capable  of  being  cast  in  moulds  of  any 
form  ;  of  being  drawn  out  into  wires  of 
any  desired  strength  or  fineness ;  of  be- 
ing extended  into  plates  or  sheets  ;  of  be- 
ing bent  in  every  direction ;  of  being 
sharpened,  hardened,  and  softened  at 
pleasure.  Iron  accommodates  itself  to 
all  our  wants,  our  desires,  and  even  our 
caprices  ;  it  is  equally  serviceable  to  the 
arts,  the  sciences,  to  agriculture,  and  war ; 
the  same  ore  furnishes  the  sword,  the 
ploughshare,  the  scythe,  the  pruning 
nook,  the  needle,  the  graver,  the  spring 
of  a  watch  or  of  a  carriage,  the  chisel,  the 
chain,  the  anchor,  the  compass,  the  can- 
non, and  the  bomb.  It  is  a  medicine  of 
much  virtue,  and  the  only  metal  friendly 
to  the  human  frame. 

The  ores  of  iron  are  scattered  over  the 
crust  of  the  globe  with  a  beneficent  pro- 
fusion, proportioned  to  the  utility  of  the 
metal ;  they  are  found  under  every  lati- 
tude, and  every  country  which  possesses 
a  range  of  primary  rocks  is  sure  to  have 
beds  of  iron  ore.     When  pure  it  is  a  me- 
tal of  a  bluish-gray  color,  and  a  dull  fi- 
brous fracture,  but  it  is  capable  of  ac- 
quiring a  brilliant  surface  by  polishing. 
Its  specific  gravity  is  7-78.    It  is  the  most 
tenacious  of  metals,  and  the  hardest  of 
all  those  which  are  malleable  and  ductile. 
It  is  singularly  susceptible  of  the  magne- 
|  tic  virtue,  but  in  its  pure  state  soon  loses 
|  it.    When  rubbed  it  has  a  slight  smell, 
i  and  it  imparts  to  the  tongue  a  peculiar 
!  astringent  taste,  called  chalybeate.    In  a 
'  moist  atmosphere,  iron  speedily  oxydizes, 
and  becomes  covered  with  a  brown  coat- 
;  ing,  called  rust. 


IRO] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


267 


There  are  no  less  than  19  ores  of  iron  : 

I,  native  iron  of  three  kinds,  pure,  metal- 
liferous, and  steely  ;  2,  arsenical  iron ;  3, 
yellow  sulphuret  of  iron  ;  4,  white  sul- 
phuret  of  iron  ;  5,  magnetic  sulphuret ; 
6,  black  oxide,  either  the  loadstone,  the 
magnetic,  or  titaniferous  ;  7,  Fer  oligigiste, 
either  specular  or  scaly;  8,  haematite, 
yielding  red  powder;  9,  yellow  haematite, 
a  hydrated  oxide ;  10,  pitchy  iron  ore ; 

II,  silico  calcareous  iron  or  zenite  ;  12, 
sparry  carbonate  and  clay  iron  stone  '}  13, 
phosphate  of  iron  ;  14,  sulphate  of  iron, 
native  copperas  ;  15,  chromate  of  iron  ; 
16,  arseniate  of  iron ;  17,  chloride  of  iron  ; 
18,  oxalate  of  iron;  19,  titanate  of  iron. 

Of  these  ores  10  are  worked  by  the  mi- 
ner of  the  native  iron,  the  magnetic  oxide, 
the  carbonate,  or  clay  iron  stone.  The 
hannatite  and  the  brown  iron  stone  are 
the  most  important. 

The  native  iron  occurs  in  veins  gener- 
ally and  is  almost  pure  iron.  The  mete- 
oric iron  contains  nickel,  and  the  mass  is 
magnetic. 

The  magnetic  oxide  or  magnetic  iron 
ore  is  a  mixture  of  protoxide  and  perox- 
ide, and  contains,  according  to  Berzelius, 
in  100  parts : 

Iron 7174 

Oxygen 28-26 

It  is  of  an  intense  black  color  crystalliz- 
ed in  regular  octohedra,  sometimes  in  gra- 
nular or  compact  masses;  its  sp.  gr.  5-094. 
This  variety  is  found  in  Warwick,  Orange 
Co.,  New-York.  The  magnetic  iron  exists 
in  the  primary  rocks  of  New  England, 
and  crosses  New-York  and  New  Jersey 
into  Pa.  It  occurs  at  Winchester  and 
Franconia,  N.  H.,  at  Cumberland,  K.  I., 
at  Hawles  and  Bernardstown,  Mass. 
Near  Ringwood,  along  the  Highlands, 
beds  of  ore  10  feet  thick  exist;  in  Morris 
county,  New  York,  its  average  thickness 
is  from  5  to  12  feet,  and  it  yields  65  per 
cent,  of  pure  iron.  In  the  primary  hills 
W.  of  Lake  Champlain,  there  are  numer- 
ous veins  and  beds  of  it  25  feet  thick  in 
some  places  and  nearlv  pure.  It  is  work- 
ed at  Peru  and  Crown  Point.  This  ore,  be- 
sides being  so  rich  in  iron,  yields  it  of  the 
greatest  purity  ;  hence  that  of  Dannemo- 
ra,  in  Sweden,  has  been  so  highly  prized. 

Chromate  of  iron,  or  chrome  iron  ore, 
is  found  massive  and  crystallized  in  octo- 
hedra, imperfect  lustre,  color  brown 
black,  sp.  gr.  4-49     It  consists  of— 

Oxide  of  chrome 5550 

Protoxide  of  Iron 83- 

Alumina 6* 

Silica 2- 


docs  not  fuse  before  the  blowpipe ;  it  is 
magnetic  after  exposure  to  the  reducing 
flame  ;  it  forms  a  green  bead  with  borax. 
In  the  United  States  it  exists  abundantly 
in  Maryland,  near  Baltimore,  also  in  small 
quantities  near  New  Haven,  Conn.,  in 
limestone  with  serpentine.  It  is  used  for 
extracting  chrome  salts.  (See  Chrome.) 
The  quantity  of  chromate  of  lead  annu- 
ally made  in  Baltimore  exceeds  80,000  lbs. 
Specular  iron  ore  and  red  iron  ore  occurs 
in  many  crystalline  forms  derived  from 
the  acute  rhomboid,  lustre  metallic,  color 
dark  steel  gray  iron  black  ;  streak  cher- 
ry red  sp.  gr.  5-25,  has  full  action  on  the 
magnet.  The  micaceous  iron  ore  and  the 
haematite,  analyzed  by  Bucholz,  have 
yielded  in  100  parts, 

Peroxide  of  iron 90-00  94-00 

Oxide  of  manganese a  trace  a  trace 

Silica 2-00  200 

Lime a  trace      1*00 

Water 2-00         3-00 

It  yields  ordinarily  60  per  cent,  of 
metal.  The  island  of  Elba  is  the  most 
celebrated  locality  which  has  afforded 
iron  for  sixteen  centuries.  It  has  been 
worked  at  Hawley,  Mass.  It  is  however 
found  but  sparingly  in  the  United  States. 
It  occurs  at  Ticonderoga,  New-York, 
where  it  is  ground  to  powder,  and  em- 
ployed as  a  polishing  substance.  It 
affords  excellent  iron,  and  often  as  much 
as  60  per  cent.  It  occurs  also  at  Mari- 
etta, Ohio. 

The  brown  iron  ore,  or  hydrated  oxide, 
does  not  occur  crystalline,  but  in  botry- 
oidal  masses,  or  in  stalactitic  lumps; 
sometimes  in  pieces  earthy  and  friable ; 
its  spec.  grav.  is  3-922.  Its  composition 
is— proxide  of  iron,  84*00  ;  water,  11-00; 
oxide  of  manganese,  2-00;  silica,  2-00. 
Its  most  remarkable  deposit  in  the 
United  States  is  at  Salisbury,  Conn., 
where  it  has  been  wrought  for  nearly  100 
years.  This  is  the  most  extensive  mine 
in  the  country,  yielding  3000  tons  per 
annum.  Other  localities  of  brown 
haematite  exist  in  Litchfield,  Conn.,  i\e 
well  as  in  the  vicinal  county  of  Duchess, 
New-York,  and  Berkshire  Mass.  The 
iron  which  this  variety  affords  is  supe- 
rior in  malleability  to  that  yielded  by  the 
red  ore  of  iron?  and  is  much  esteemed 
also.  This  ore  is  abundant  in  Pa.,  yield- 
ing from  45  to  55  per  cent,  of  metal. 
Hannatite  is  abundant  in  Wisconsin. 
Iron  was  first  found  in  this  country  in 
Virginia,  in  1715.  In  many  parts  o/ 
Missouri  the  iron  is  so  pure  as  not  to  re- 
quire the  preliminary  roasting,  and  the 
iron  mountain  of  that  state  lias  a  circuit 


268 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


Tiro 


of  two  miles,  and  an  elevation  of  350 
feet.  It  consists  of  specular  iron,  yield- 
ing: 70  per  cent,  of  metal,  and  contains 
only  a  few  crystals  of  felspar. 

The  general  principles  which  regulate 
the  treatment  of  ores,  will  be  found  given 
under  the  article,  Metallurgy.  Some 
general  notions  of  the  particular  treat- 
ment of  iron  ores  are  given  here.  After 
raising  the  ore  it  has  to  be  picked,  to 
separate  valuable  from  worthless  ore,  or 
mere  stone.  They  are  next  roasted  in 
large  heaps  in  the  open  air  to  drive  off  the 
sulphur  and  arsenic  which  they  usually 
contain,  and  also  render  them  more  fri- 
able and  easier  to  be  powdered.  In  Eng- 
land the  roasting  is  conducted  with  bitu- 
minous coal,  but  in  this  country  alto- 
gether with  charcoal.  Trunks  of  trees 
and  brushwood  are  laid  down  and  over- 
laid with  charcoal,  and  ignited.  Upon 
the  top  of  this  the  ore  is  heaped  several 
feet  high.  After  being  roasted  the  ore  is 
transferred  to  the  crushing  mill,  where  it 
undergoes  another  powdering,  when  it  is 
transferred  to  the  smelting  furnace  to  be 
converted  into  iron.  Here  it  passes 
through  two  distinct  operations  :  1.  The 
reduction  of  the  oxide  to  the  state  of  pure 
metal ;  2.  The  separation  of  the  earthy 
matters  as  scoria?. 

These  processes  consist  in  exposing  the 
ore,  generally  mixed  with  fluxes,  to  the 
action  of  carbon  at  a  high  temperature  in 
furnaces,  urged  by  bellows,  hence  called 
blast  furnaces,  or  sometimes  high  fur- 
naces. 

The  height  of  the  blast  furnace  is  very 
variable;  some  being  only  36  feet  high 
including  the  chimney,  while  others  have 
an  elevation  of  60  feet.  These  extreme 
limits  are  very  rare  :  so  that  the  greater 

{mrt  of  the  furnaces  are  from  45  to  50  feet 
ligh.  They  are  all  terminated,  by  a  cyl- 
indrical chimney  of  from  8  to  12  feet 
long;  being  about  one  fifth  of  the  total 
height  of  the  furnace.  The  inside  diame- 
ter of  this  chimney  is  the  same  as  that  of 
the  throat  or  mouth ;  and  varies  from  4 
to  6  feet.  The  chimney  is  frequently 
formed  of  a  single  course  of  bricks,  and 
acquires  solidity  from  its  hoops  of  iron, 
so  thickly  placed  that  one  half  of  the  sur- 
face is  often  covered  with  them.  At  its 
lower  end,  the  mouth  presents  one  or  two 
rectangular  openings,  through  which  the 
charge  is  given.  It  is  built  on  a  base- 
ment circle  of  cast-iron,  which  forms  the 
circumference  of  the  throat ;  and  a  slop- 
ing plate  of  cast-iron  is  so  placed  as  to 
make  the  materials  slide  over  into  the 
furnace,  as  shown  in  the  figure. 


The  inside  of  the  blast  furnaces  of  Staf- 
fordshire is  most  frequently  of  a  circular 
form,  except  the  hearth  and  working 
area.  The  inner  space  is  divided  into 
four  portions,  different  in  their  forms, 
and  the  functions  which  they  fulfil  in  the 
smelting  of  the  ore. 

The  undermost,  called  the  hearth,  or 
crucible,  in  which  the  cast-iron  collects, 
is  a  right  rectangular  prism,  elongated  in 
a  line  perpendicular  to  the  axes  of  the 
tuyeres.  The  sides  of  the  hearth  consist 
in  general  of  refractory  sandstone  (fire- 
stone),  obtained  mostly  from  the  bed  of 
the  coal  basin,  called  millstons  grit  •  and 
the  bottom  of  the  hearth  is  formed  of  a 
large  block  of  the  same  nature,  laid  on  a 
cast-iron  plate.  In  this  country  it  is 
chiefly  a  mica  slate,  or  gneiss  rock,  con- 
taining a  large  mixture  of  quartz. 

The  second  portion  is  also  made  of  the 
same  refractory  grit  stone.  It  has  the 
form  of  a  quadrangular  pyramidal,  ap- 
proaching considerably  to  a  prism,  from 
the  smalfness  of  the  angle  included  be- 
tween the  sides  and  the  axis. 

The  third  portion,  or  lower  body  of  the 
furnace,  is  conical,  but  hei'e  the  interior 
space  suddenly  expands ;  the  slope  out- 
wards at  this  part  seems  to  have  a  great 
influence  on  the  quality  of  the  cast-iron 
obtained  from  the  furnace.  When  No.  2 
of  the  blackest  kind  is  wanted  for  cast- 
ings, the  inclination  of  this  cavity  of  the 
furnace  is  in  general  less  considerable 
than  when  No.  2  cast-iron  for  conversion 
into  bar-iron  is  required.  The  inclina- 
tion of  this  conical  chamber,  called  the 
boshes,  varies  from  55  to  60  degrees  with 
the  horizon.  The  diameter  of  this  part  is 
equal  to  that  of  the  belly,  and  is  from  11 
to  13  feet.  The  boshes  are  built  ot 
masonry,  as  shown  in  the  following  fig- 
ure. 

The  fourth  part,  which  constitutes 
about  two  thirds  of  the  height  of  the  fur- 
nace from  the  base  of  the  hearth  up  to 
the  throat,  presents  the  figure  of  a  sur- 
face of  revolution,  generated  by  a  curve 
whose  concavity  is  turned  towards  the 
axis  of  the  furnace,  and  whose  last  tan- 
gent towards  the  bottom  is  almost  verti- 
cal. This  surface  is  sloped  off  with  that 
of  the  boshes,  so  that  no  sharp  angle  may 
exist  at  the  belly.  In  some  furnaces  of 
considerable  dimensions,  as  in  that  with 
three  tuyeres,  this  portion  of  the  furnace 
is  cylindrical  for  a  certain  height. 

The  conical  orifice  called  the  tuyere,  in 
which  the  tapered  pipes  are  placed,  for 
imparting  the  blast,  is  seen  near  the  bot- 
tom of  the  furnace,  fig.  59,  at  a.    Noso 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


269 


tubes  of  various  sizes,  from  2  to  4  inches 
in  diameter,  are  applied  to  the  extremity 


of  the  main  blast-pipe.  Under  a  is  the 
bottom  of  the  hearth,  which,  in  large  fur- 
naces, may  be  two  feet  square,  b  is  the 
top  of  the  hearth,  about  two  feet  six  in- 
ches square,  a  b  is  the  height  of  the 
hearth,  about  six  feet  six  inches,  b  shows 
the  round  bottom  of  the  conical  or  funnel 
part,  called  in  this  country  the  boshes, 
standing  upon  the  square'  area  of  the 
hearth,  c  is  the  top  of  the  boshes,  which 
may  be  about  12  feet  in  diameter,  and  8 
feet  in  perpendicular  height,  d  is  the 
furnace  top  or  mouth,  (gueulard  in 
French,)  at  which  the  materials  are 
charged.  It  may  be  4i  feet  in  diameter. 
The  line  between  c,  d,  is  the  height  of 
the  internal  cavity  of  the  furnace,  from 
the  top  of  the  boshes  upwards,  supposed 
to  be  30  feet,  a,  d,  is  the  total  height  of 
the  interior  of  the  furnace,  reckoned  at 
44i  feet,  e  e  is  the  lining,  which  is  built 
in  the  nicest  manner  with  the  best  fire- 
bricks, from  12  to  14  inches  long,  3  inches 
thick,  and  curved  to  suit  the  circle  of  the 
cone.  A  vacancy  of  3  inches  wide  is  left 
all  round  the  outside  of  the  first  lining  by 
the  builder;  which  is  sometimes  filled 
with  coke  dust,  but  more  generally  with 
sand  firmly  rammed.  This  void  space  in 
the  brick-work  is  for  the  purpose  of 
allowing  for  any  expansion  which  might 
occur,  either  by  an  increase  in  the  bulk 
of  the  building,  or  by  the  pressure  and 
weight  of  the  materials  when  descending 
to  the  bottom  of  the  furnace.   Exterior  to 


e  e  is  a  second  lining  of  fire-bricks  simi- 
lar to  the  first.  At  f,  on  either  side,  is  a 
cast-iron  lintel,  8s  feet  long,  by  10  inches 
square,  upon  which  the  bottom  of  the 
arches  is  supported,  r,  o,  is  the  rise  of 
the  tuyere  arch,  which  may  be  14  feet 
high  upon  the  outside,  and  18  feet  wide. 
The  extreme  size  of  the  bottom  or  sole  of 
the  hearth,  upon  each  side  of  a,  may  be 
10  feet  square.  This  part  and  the  bosh- 
ing stones  are  preferably  made  from  a 
coarse  sandstone  grit,  containing  large 
rounded  grains  of  quartz,  united  by  a 
siliceo-argillaceous  cement. 

The  blowing  machines  employed  in 
Staffordshire  are  generally  cast-iron  cyl- 
inders, in  which  a  metallic  piston  is  ex- 
actly fitted  as  for  a  steam  engine,  and 
made  in  the  same  way.  Towards  the  top 
and  bottom  of  the  blowing  cylinders,  ori- 
fices are  left  covered  with  valves,  which 
open  inside  when  the  vacuum  is  made 
with  the  cylinders,  and  afterwards  shut 
by  their  own  weight.  Adjutages  conduct 
into  the  iron  globe  or  chest,  the  air  ex- 
pelled by  the  "piston,  both  in  its  ascent 
and  descent;  because  these  blowing 
machines  have  always  a  double  stroke. 

As  soon  as  the  blast  furnace  gets  into 
a  regular  heat,  which  happens  about  15 
days  or  three  weeks  after  fires  have  been 
put  in  it,  the  working  consists  simply  in 
charging  it,  at  the  opening  in  the  throat, 
whenever  there  is  a  sufficient  empty 
space;  the  only  rule  being  to  keep  the 
furnace  always  full.  The  coke  is  measur- 
ed in  a  basket,  thirteen  of  which  go  to  the 
ton.  The  ore  and  the  flux  (limestone) 
are  brought  forwards  in  wheel-barrows 
of  sheet  iron.  In  24  hours,  there  are 
thrown  into  a  furnace  the  following: 
14£  tons  of  coke,  16  tons  of  roasted  ore, 
and  6|  tons  of  limestone;  from  which 
about  7  tons  of  pig  iron  are  procured. 
This  is  run  off  every  12  hours ;  in  some 
works  the  blast  is  suspended  during  the 
discharge.  The  metal  intended  to  be 
converted  into  bar  iron,  or  to  be  cast 
again  into  moulds,  is  run  into  small  pigs 
3feet  long,  and  4  inches  diameter ;  weigh- 
ing each  about  two  hundred  weight  and  a 
half. 

The  disorders  to  which  blast  furnaces 
are  liable  have  a  tendency  always  to  pro- 
duce white  cast-iron.  The  color  of  the 
slag  or  scoria?  is  the  surest  test  of  these 
derangements,  as  it  indicates  the  quality 
of  the  products.  If  the  furnace  is  yield- 
ing an  iron  proper  for  casting  into  moulds, 
the  slag  has  a  uniform  vitrification,  and 
is  slightly  translucid.  "When  the  dose  of 
ore  is  increased  in  order  to  obtain  a  gray 


270 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[iRO 


pig  iron,  fit  for  fabrication  into  bars,  the 
slag  is  opaque,  dull,  and  of  a  greenish- 
yellow  tint,  with  blue  enamelled  zones. 
Lastly,  when  the  furnace  is  producing  a 
white  metal,  the  slags  are  black,  glassy, 
full  of  bubbles,  and  emit  an  odor  of  sul- 
phureted  hydrogen.  The  scoriae  from  a 
coke  are  much  more  loaded  with  lime 
than  those  from  a  charcoal  blast  furnace. 
This  excess  of  lime  appears  adapted  to 
absorb  and  carry  off  the  sulphur,  whicn 
would  otherwise  injure  the  quality  of  the 
iron.  The  slags,  when  breathed  on,  emit 
an  argillaceous  odor. 

A  blast  furnace  of  50  or  60  feet  in 
height  gives  commonly  from  60  to  70  tons 
of  cast-iron  per  week ;  one  from  50  to  55 
feet  high,  gives  60  tons  ;  two  united  of  45 
feet  produce  together  100  tons  ;  and  one 
of  36  feet  furnishes  from  30  to  40.  A 
blast  furnace  should  go  for  four  or  five 
years  without  needing  restoration.  From 
3i  to  4  tons  of  coal,  inclusive  of  the  coal 
of  calcination,  are  required  in  Stafford- 
shire to  obtain  one  ton  of  cast-iron  ;  and 
the  expense  in  workmen's  wages  is  about 
15  shillings  British  on  that  quantity. 

Heated  air  is  applied  in  some  iron- 
works. Where  this  method  of  working 
the  ore  has  been  introduced,  the  air  is 
blown  by  cylinder-bellows  in  the  usual 
manner,  but  before  entering  the  smelt- 
ing-furnace  it  passes  through  pipes  of 
cast-iron,  heated  to  redness,  which  are 
altogether  about  thirty  feet  in  length  and 
three  feet  in  diameter.  They  are  usually 
made  in  three  or  four  pieces,  joined 
together  by  apertures  considerably  less 
than  three  feet  in  diameter,  and  placed 
horizontally,  or  in  whatever  manner  the 
local  arrangements  about  the  furnace  may 
render  most  convenient.  A  brick  arch 
is  then  thrown  round  the  pipes,  leaving 
a  free  space  of  about  eight  inches,  and 
upwards,  between  it  and  them,  and  two 
or  more  furnaces  constructed,  so  as  to 
heat  the  pipes  in  the  archway,  the  flues 
playing  into  it,  and  terminating  in  a  com- 
mon vent  at  the  farther  extremity.  They 
may  be  considered,  therefore,  as  placed 
on  the  floor  of  a  long  and  narrow  rever- 
beratory  furnace,  about  six  feet  high,  and 
nearly  of  the  same  breadth,  being  at  the 
same  time  protected  by  fire-bricks,  when 
they  might  be  injured  by  the  direct  flame 
of  the  furnaces.  The  iron  ore  is  smelted, 
according  to  this  plan,  with  little  more 
than  half  the  coaf  necessary  when  the 
furnaces  are  worked  with  air'in  the  usual 
manner ;  the  small  coal,  which  is  sold  at 
an  inferior  price,  is  found  quite  sufficient 
for  heating  the  pipes. 


The  number  of  charges  in  English  fur- 
naces, given  in  12  hours,  is  different,  in 
different  furnaces,  being  20,  25,  and  even 
up  to  40  ;  30  is  an  average.  Each  charge 
is  composed  of  from  5  to  6  cwts.  of  coke 
(or  now  of  3  to  4  cwts.  of  coal  with  the 
hot  blast) ;  3,  4,  and  sometimes  6  cwts. 
of  the  roasted  mine,  according  to  its 
richness  and  the  quality  of  cast  iron 
wanted  ;  the  limestone  flux  is  usually  one 
third  of  the  weight  of  the  roasted  iron 
stone.  There  are  2  casts  in  24  hours ; 
one  at  6  in  the  morning,  and  another  at 
6  in  the  evening. 

According  to  M.  Berthier's  analysis,  the 
slag  or  cinder  of  Dowlais  furnace  consists 
of  silica,  40'4;  lime,  38-4;  magnesia,  5*2; 
alumina,  11*2  ;  protoxyde  of'  iron,  3-8 ; 
and  a  trace  of  sulphur.  He  says  that  the 
silica  contains  as  much  oxygen  as  all  the 
other  bases  united ;  or  is  equivalent  to 
them  in  saturating  power;  and  to  the 
excess  of  lime  he  ascribes  the  freedom 
from  sulphur,  and  the  good  quality  of 
the  iron  produced.  The  specimen  ex- 
amined was  from  a  furnace  at  Merthyr- 
Tydvil.  Other  slabs  from  the  same  fur- 
nace, and  one  from  Dudley,  furnished 
upwards  of  2  per  cent  of  manganese. 
Those  which  he  analyzed  from  Saint 
Etienne,  in  France,  afforded  about  1  per 
cent,  of  sulphur. 

As  the  ignition  in  the  blast  furnace 
proceeds,  and  the  blast  let  on,  the  metal 
in  the  ore  parts  with  its  oxygen,  and  sub- 
sides to  the  bottom  of  the  furnace,  cov- 
ered with  a  melted  slag.  This  last  is  oc- 
casionally allowed  to  flow  off,  by  opening 
some  of  the  side  holes  which  were  stop- 
ped with  clay,  and  when  the  bottom  of 
the  furnace  becomes  charged  with  metal, 
which  it  does  after  five  or  six  hours,  the 
iron  itself  is  discharged,  by  one  of  these 
openings,  into  a  pit  of  sand  mixed  with 
clay.  As  soon  as  the  iron  is  poured  out, 
the  hole  is  closed,  and  the  furnace  is  still 
kept  at  work,  and  eroes  on  reducing  iron 
for  six  months.  The  flux  employed  to 
assist  the  fusion  of  the  ore,  by  vitrifying 
the  earths  aforesaid  with  iron,  is  lime^- 
stone  of  the  best  quality  ;  very  lately,  it 
has  been  proposed  to  use  caustic  lime,  or 
that  which  has  been  burned,  instead  of 
the  crude  limestone.  It  is  said  to  pro- 
duce an  economy  of  fuel. 

The  iron  which  has  run  out  from  the 
furnace,  is  cast  iron,  or  iron  with  carbon 
intermingled  with  it,  sometimes  to  the 
extent  of  5  per  cent.  It  has  a  coarse 
grain,  and  is  very  brittle.  The  mould  in 
"which  the  metal  flows,  is  of  a  longish 
shape,  having  projecting  offsets  on  each 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


271 


side,  which,  from  some  fancied  resem- 
blance to  a  sow  and  her  litter,  has  been 
called  pig  iron. 

To  convert  this  pig  or  crude  iron  into 
bar  iron,  it  has  to  be  refined.  This  con- 
sists in  placing  it  in  a  furnace,  like  a 
smith's  forge,  or  hearth,  with  a  sloping 
cavity  sunk  a  foot  below  the  blast  pipe. 

In  the  finery  process,  the  hearth  or 
crucible  of  the  furnace  is  filled  with  coke  ; 
then  six  pigs  of  cast  iron  are  laid  hori- 
zontally on  the  hearth,  namely,  four  of 
them  parallel  to  the  four  sides,  and  two 
in  the  middle  above  ;  and  the  whole  is 
covered  up  in  a  dome-form,  with  a  henp 
of  coke.  The  fire  is  now  lighted,  and  in 
a  quarter  of  an  hour  the  blast  is  applied. 
The.  cast  iron  flows  down  gradually,  and 
collects  in  the  crucible  ;  more  coke  being 
added  as  the  first  quantity  burns  away. 
The  operation  proceeds  by  itself;  the 
melted  metal  is  not  stirred  about,  as  in 
some  modes  of  refinery,  and  the  temper- 
ature is  always  kept  high  enough  to  pre- 
serve the  metal  liquid.  During  this 
stage  the  coals  are  observed  continually 
heaving  up,  a  movement  due,  in  part, 
to  the  action  of  the  blast,  and  in  part  to 
an  expansion  caused  in  the  metal  by  the 
discharge  of  gaseous  oxyde  of  carbon. 
When  all  the  pig  iron  is  collected  at  the 
bottom  of  the  hearth,  which  happens 
commonly  at  the  end  of  two  hours,  or 
two  and  a  half,  the  tap-hole  is  opened, 
and  the  fine-  metal  flows  out  with  the 
slag,  into  the  loam-coated  pit,  on  a  plate 
10  feet  long,  and  3  broad,  and  from  2 
inches  to  2s  thick.  A  portion  of  the 
slag  forms  a  small  crust  on  the  surface 
of  the  metal ;  but  most  part  of  it  collects 
in  a  basin  scooped  out  at  the  bottom  of 
the  pit,  into  which  the  fine  metal  is  run. 

A  large  quantity  of  water  is  thrown  on 
the  metal,  with  the  view  of  rendering  it 
brittle,  and  perhaps  of  partially  oxydiz- 
ing  it.  This  metal,  suddenly  cooled,  is 
very  white,  and  possesses  in  general  a 
fibrous  radiated  texture  ;  or  sometimes  a 
cellular,  including  a  considerable  number 
of  small  spherical  cavities,  like  a  decom- 
posed amygdaloid  rock.  If  the  cast  iron 
be  of  bad  quality,  a  little  limestone  is  oc- 
casionally used  in  the  above  operation. 

Three  samples  of  cinder,  analyzed  by 
Berthier,  gave  : 

1.  Silica,  0-276  ;  protox.  of  iron,  0-612  ; 
alumina,  0*040  ;  phosp.  acid,  0*072,  Dud- 
ley. 

2.  Silica,  0*368 ;  protox.  of  iron,  0*610  ; 
alumina,  0*01 5  ;  puddling  of  Dowlais. 

3.  Silica,  0*424;  protox.  of  iron,  0*520; 
alumina,  0*033  ;  puddling  of  Dowlais. 


The  remarkable  fact  of  the  presence  of 
phosphoric  acid,  shows  how  important 
this  operation  is  to  the  purification  of  the 
iron.  The  charge  varies  from  a  ton  and 
a  quarter  to  a  ton  and  a  half  of  pigs  ;  and 
the  loss  by  the  process  varies  from  12  to 
17  per  cent. 

The  fine  metal  thus  obtained  is  broken 
in  pieces,  and  sent  to  the  puddling  fur- 
nace. This  is  a  reverberatory  furnace, 
which  is  charged  by  shovelling  in  the 
fine  metal,  and  laying  it  all  round  the 
sides  of  the  earth,  raising  the  heap  to  the 
roof;  the  middle  of  the  hearth  is  left  clear. 
The  fuel  is  then  placed  in  the  grate,  and 
the  doors  closed*  in  20  minutes  the 
metal  becomes  white,  melts,  and  falls  in 
drops  to  the  sole  of  the  furnace  ;  the  fire 
is  then  gradually  checked,  and  the  pieces 
separated  so  that  the  whole  may  not  be- 
come too  fluid,  but  remain  as  a  pasty 
mass ;  as  the  heat  is  continued  and  stir- 
red, %ae  mass  gets  drier,  and  carbonic  ox- 
ide, which  at  first  was  freely  given,  now 
gradually  lessens,  and  ultimately  ceases. 

The  workman,  with  his  paddle,  now 
works  the  mass  into  lumps  or  balls  of 
70  lbs.  weight.  The  balls  are  lifted  out, 
and  are  fit  for  being  hammered.  The 
whole  object  of  the  puddling  has  been  to 
remove  the  carbon  out  of  the  iron,  to 
which  its  fluidity  was  due  ;  as  the  carbon 
escapes,  the  fusibility  of  the  mass  di- 
minishes. 

The  puddled  balls  have  now  to  under- 
go the  next  process,  which  is  that  cf  ham- 
mering or  condensing  the  fibres,  of  weld- 
ing them,  and  giving  the  mass  the  form 
of  a  bar. 

In  England  there  are  employed  for  the 
forging  and  drawing  out  of  the  iron,  cast- 
iron  hammers  of  great  weight,  and  cylin- 
ders of  different  dimensions,  for  beating 
out  the  balls,  or  extending  the  iron  bars, 
as  also  powerful  shears.  These  several 
mechanisms  are  moved  either  by  a  steam 
engine,  as  in  Staffordshire,  and  in  almost 
all  the  other  counties  of  England,  or  by 
water-wheels  when  the  localities  are  fa- 
vorable, as  in  many  establishments  in 
South  Wales.  We  shall  here  offer  some 
details  concerning  these  machines. 

The  main  driving  shaft  usually  carries 
at  cither  end  a  large  toothed  wheel,  which 
communicates  motion  to  the  different 
machines  through  smaller  toothed  wheels. 
Of  these,  there  are  commonly  six,  four  of 
which  drive  four  different  systems  of 
cylinders,  and  the  two  others  work  the 
hammer  and  the  shears.  The  different 
cylinders  of  an  iron  work  should  never 
be  placed  on  the  same    arbor,  because 


272 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[iRO 


they  are  not  to  move  together,  and  they 
must  have  different  velocities,  according 
to  their  diameter.  In  order  to  economize 
time  and  facilitate  labor,  care  is  taken  to 
associate  on  one  side  of  the  motive  ma- 
chine the  hammer,  the  shears,  and  the 
reducing  cylinders;  and,  on  the  other 
side  to  place  the  several  systems  of  cylin- 
ders for  drawing  out  the  iron  into  bars. 
For  the  same  reason  the  puddling  fur- 
naces ought  to  be  grouped  on  the  side  of 
the  hammer  ;  and  the  reheating  furnaces 
on  the  other  side  of  the  works. 

The  hammers  are  made  entirely  of  cast- 
iron  ;  they  are  nearly  10  feet  long,  and 
consist  usually  of  two  parts,  the  helve 
and  the  head  or  pane.  The  latter  enters 
with  friction  into  the  former,  and  is  re- 
tained in  its  place  by  wedges  of  iron  or 
wood.  The  head  consists  of  several  faces 
or  planes  receding  from  each  other ;  for 
the  purpose  of  giving  different  forms  to 
the  ball  lumps.  A  ring  of  cast-iron  call- 
ed the  cam-ring  bag,  bearing  movable 
cams,  drives  the  hammer,  by  lifting  it 
up  round  its  fulcrum,  and  then  letting  it 
fall  alternately.  In  one  iron  work,  this 
ring  was  found  to  be  3  feet  in  diameter, 
18  inches  thick,  and  to  weigh  4  tons.  The 
weight  of  the  helve  (handle)  of  the  cor- 
responding hammer  was  3  tons  and  a 
half,  and  that  of  the  head  of  the  hammer, 
8  hundred  weight. 

The  anvil  consists  also  of  two  parts ; 
the  one  called  the  pane  of  the  anvil,  is 
the  counterpart  of  the  pane  of  the  ham- 
mer ;  it  likewise  weighs  eight  hundred 
weight.  The  second,  named' the  stock  of 
the  anvil,  weighs  4  tons.  Its  form  is  a 
parallelopiped,  with  the  edges  rounded. 
The  bloom  or  rough  ball,  from  the  puddle 
furnace,  is  laid  and  turned  about  upon 
it,  by  means  of  a  rod  of  iron  welded  to 
each  of  them,  called  a  porter.  Since  the 
weight  of  these  pieces  is  very  great,  and 
the  shocks  very  considerable,  the  utmost 
precautions  should  be  taken  in  setting 
the  hammer  and  its  anvil  upon  a  sub- 
stantial mass  of  masonry,  as  shown  in  the 
figure,  over  which  is  laid  a  double,  or 
even  quadruple  flooring  of  wood,  formed 
of  beams  placed  in  transverse  layers  close 
to  each  other.  Such  beams  possess  an 
elastic  force,  and  thereby  partially  destroy 
the  injurious  reaction  of  the  shock.  In 
some  works,  a  six-feet  cube  of  cast  iron  is 
placed  as  a  pedestal  to  the  anvil. 

Forge  hammers  are  very  frequently 
mounted  as  levers  of  the  first  kind,  with 
the  centre  of  motion  about  one  third  or 
one  fourth  the  length  of  the  helve  from 
the  cam  wheel. 


When  well  hammered  by  these  trip 
i  hammers,  the  mass  is  made  to  pass  be- 
tween grooved  cylinders,  which  press 
it  into  the  bar  shape  ;  as  it  emerges  from 
the  cylinders  it  is  cut  with  a  shears  into 
shorter  lengths. 

Such  is  a  rough  outline  of  the  mode  of 
obtaining  bar  or  wrought  iron,  as  prac- 
tised in  England.  In  France,  and  the 
south  of  Europe,  as  woll  as  in  many 
places  in  this  country,  it  is  differently 
conducted. 

Malleable  iron  is  frequently  obtained 
direct  from  the  ores  by  one  fusion,  when 
the  metallic  oxide  is  not  too  much  conta- 
minated with  foreign  substances ;  this 
mode,  which  is  allowed  to  be  much  more 
economical  than  the  one  described,  as  it 
saves  time  and  combustibles,  has  for  a 
long  period  been  employed  in  Catalonia, 
in  the  Pyrenees,  from  which  circum- 
stances it  is  called  the  method  of  the 
Catalan  forge.  Those  ores,  best  adapted 
to  its  treatment,  are  the  pure  black  ox- 
ide, red  and  brown  oxide,  and  carbonate 
of  iron  ;  to  extract  the  metal  from  which, 
it  is  sufficient  to  expose  them  to  a  high 
temperature  in  contact  with  charcoal  or 
carbonaceous  gases.  The  furnace  em- 
ployed is  similar  to  the  refining  forge 
previously  described.  The  crucible  is  a 
semicircular  or  oblong  basin,  18  inches 
diameter,  and  8  or  10  deep,  excavated  in 
an  area  or  small  elevation  of  masonry 
8  or  10  feet  long,  by  6  broad,  and  covered 
in  with  a  chimney.  The  tuyeres  stand  5 
or  6  inches  above  the  basin,  and  have  a 
slight  inclination  downwards,  and  the 
blast  is  given  by  a  water  blowing  machine. 
The  first  step  consists  in  expelling  the 
water  combined  with  oxide,  as  well  as 
the  sulphur  and  arsenic.  When  those 
combinations  are  present,  this  is  done  as 
usually  by  roasting  in  the  air.  The  roast- 
ed ore  is  crushed  to  a  fine  powder,  and 
thrown  by  the  shovel  at  intervals  on  the 
charcoal  fire  of  the  hearth  ;  the  side  sand 
bottom  of  the  basin  being  previously  lined 
with  two  or  three  brasgues  (coats  of 
pounded  charcoal).  It  gradually  softens 
and  unites  into  lumps,  more  or  less  co- 
herent, which  finally  melt  and  accumu- 
late in  the  bottom  of  the  crucible  or  basin, 
and  a  thin  slag  is  occasionally  let  off  from 
the  upper  surface  of  the  melted  iron  by 
the  holes,  which  can  be  opened  at  discre- 
tion. The  melted  iron  preserves  a  pasty 
condition,  owing  to  the  heat  communi- 
cated from  above,  and  when  a  mass  suffi- 
ciently large  is  accumulated,  it  is  remov- 
ed, put  under  the  hammer,  and  forged 
at  once.    A  lump  or  bloom  of  malleable 


IRO] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


213 


iron  is  thus  produced  in  three  or  four 
hours.  The  iron  is  generally  soft,  very 
malleable,  and  a  little  steely.  Four  work- 
men are  employed  at  one  forge,  and  by  a 
relief  every  six  hours,  they  can  make  86 
cwt.  of  iron  per  week.  100  pounds  of  iron 
are  obtained,  in  this  forge,  from  300 
lbs.  of  ore.  This  process,  generally  called 
blooming,  is  one  now  increasing  in  this 
country. 

Mr.  W.  Lyman  first  put  into  successful 
operation  at  Pottsville,  Pa.,  in  1830,  a 
furnace  for  smelting  iron  by  anthracite 
with  the  hot  blast.  In  1840,  Messrs. 
Biddle,  Chambers  &  Co.  did  the  same 
at  Dansville,  Pa.,  and  others  followed. 

Anthracite  coal  is  now  always  used 
with  hot  air  in  smelting,  and  the  pud- 
dling is  performed  by  Detmold's  patent, 
with  ignited  gas.  In  Maryland  bitumin- 
ous coal  is  used,  in  New  York  charcoal. 
Blooming  or  making  the  bar  iron  by  one 
operation,  without  the  use  of  the  blast 
furnace  is  common  in  Connecticut,  New 
York,  and  Vermont. 

In  1845,  Clinton  and  Essex  Co.,  N.  Y\, 
produced  13,000  tons  of  iron.  The  whole 
produce  in  the  States  same  year  was  esti- 
mated at  919,100  tons  =  $41,734,610.  In 
New- York,  the  mines  of  Dutchess  and 
Columbia  Co.  yield  20,000  tons  annually ; 
Essex  Co.  1,500  tons,  Clinton  3,000, 
Franklin  600  :  St.  Lawrence  2,000, 
amounting  in  all  to  a  value  of  more  than 
$500,000.  In  Ohio  1200  square  miles  are 
underlaid  with  iron,  and  calculated  to 
contain  1,080,000,000  tons.  In  Tennessee 
100,000  tons  are  manufactured  yearly. 

The  following  is  the  process  recently 
adopted  by  Mr.  Alexander  Dickson,  of 
Newark. 

"  The  fire  is  placed  at  the  end,  under  a 
horizontal  bed  of  fire-brick  some  twelve 
or  fifteen  feet  in  length — the  fire  passing 
through  to  the  ether  extremity.  In  the  cen- 
tre, and  over  the  bed,  is  erected  a  double 
cylinder,  which  is  filled  with  crushed  ore 
and  pulverized  anthracite  coal.  The  in- 
tense flame  surrounds  the  cylinder,  and 
also  passes  through  the  inner  cylinder, 
which  removes  the  oxygen  and  all  other 
impurities  with  the  presence  of  atmos- 
pheric air.  Being  thus  prepared,  the  ore 
gradually  melts  and  descends  to  the 
hearth,  where  it  first  comes  in  contact 
with  the  fire,  which  destroys  the  remain- 
der of  the  pulverized  coal  by  frequent 
stirring,  and  the  iron  is  thus  partially 
formed.  From  this  hearth  it  is  thrown 
to  another  about  eight  inches  lower  than 
the  first,  where  it  is  worked  into  balls  of 
about  one  hundred  pounds  amid  the  same 
12* 


sheet  of  fire,  and  in  a  few  minutes  the 
ball  is  withdrawn  and  put  under  the 
hammer  to  put  it  in  shape,  which  con- 
cludes the  process. 

Mr.  Wall,  of  England,  has  patented  a 
process  for  removing  the  phosphorus  out 
of  iron.  The  process  consists  of  two 
parts ;  first,  in  adding  certain  substances 
to  the  metal,  while  in  a  state  of  fusion: 
2nd,  in  applying  electricity  to  the  metal 
while  in  a  state  of  fusion,  and  during  its 
cooling.  In  carrying  out  the  first  part, 
two  compounds  are  made  use  of,  termed 
A  and  B. 

The  compound  A  is  formed  by  mix- 
ing two  parts  of  iron  filings  or  turnings 
with  five  parts  of  black  resin,  by  melting 
the  resin  and  stirring  in  the  iron  filings. 
When  the  mass  has  sufficiently  cooled  it 
is  made  into  balls  of  about  five  pounds 
weight  each  ;  and  in  using  them  these 
balls  are  thrown  in  the  melting-furnace 
on  the  surface  of  the  fused  metal,  in  the 
proportion  of  one  of  the  balls  to  every  5 
cwt.  of  metal.  The  compound  B  is 
formed  by  thoroughly  mixing  two  parts 
of  common  salt  and  five  parts  of  resin, 
turpentine,  or  other  carbonaceous  matter, 
and  making  this  also  into  balls  of  about 
five  pounds  each,  and  throwing  these  on 
to  the  surface  of  the  melted  metal,  in  the 
proportion  of  one  pound  to  each  cwt.  of 
the  metal,  after  the  compound  A  has 
been  employed.  In  carrying  out  the  sec- 
ond part,  a  battery  is  employed,  consist- 
ing of  platinum  and  zinc  plates,  contain- 
ing eight  pairs,  6  inches  by  4  of  active 
surface,  in  separate  cells  of  dilute  sul- 
phuric and  strong  nitric  acid,  arranged 
in  the  manner  commonly  known  as 
Grove's  battery,  or  32  pairs  of  same  sized 
plates,  arranged  in  the  manner  commonly 
known  as  Smec's  battery,  which  give  suf- 
ficent  electricity  for  all  general  purposes. 
In  applying  the  electric  current  a  rod  of 
iron  is  inserted  into  each  extremity  of 
the  mould,  into  which  the  metal  is  to  bo 
cast,  if  the  casting  be  horizontal  ;  or  into 
the  bottom  and  top  of  the  mould,  if  the 
casting  is  vertical.  These  two  rods  of 
iron  are  connected  with  the  two  poles  of 
the  battery  respectively  ;  and  when  the 
melted  metal  is  poured  into  the  mould, 
it  serves  to  complete  the  circuit,  and  elec- 
tricity will  continue  to  traverse  it  as  long 
as  the  connection  with  the  poles  of  the 
battery  remains  unbroken.  The  current 
should  be  kept  up  for  a  considerable  time 
even  after  the  metal  has  solidified  ;  but 
if  continued  for  too  long  a  time,  the  metal 
would  be  decarbonated  and  convert- 
ed into    wrought    iron.     The    patentee 


274 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[iRO 


also  passes  an  electric  current  through 
the  fused  metal  while  in  the  furnace,  by 
inserting  a  rod  of  iron  in  the  lower  part 
of  the  furnace  so  as  to  be  in  contact  with 
the  metal,  which  rod  is  attached  to  one 
pole  of  the  battery,  while  another  rod  in 
connection  with  the  opposite  pole  is 
moved  by  the  operator  in  constant  con- 
tact with  the  melted  mass,  over  every 
part  of  the  surface,  thus  directing  the 
current  through  every  portion  of  it. 

Overman,  in  his  work,  says,  "  Hydra- 
ted  Oxide  of  Iron,  Brown"  Oxide,  He- 
matite Bog  Ore,  should  all  be  roasted, 
not  for  the  purpose  of  oxidation,  but  to 
drive  off  the  acids,  and  destroy  the  sul- 
phurets  and  phosphurets — all  ores  of  this 
class  contain  more  or  less  injurious  mat- 
ter. Sulphates  of  iron  should  be  care- 
fully roasted,  so  should  phosphates,  with 
a  liberal  access  of  air." 

The  more  carbon  that  is  present,  the 
greater  difficulty  there  is  to  drive  off  the 
phosphorus,  for  carbon  is  necessary  in 
every  case  to  produce  a  combination  of 
phosphorus  with  the  metal — the  process 
of  Wall,  therefore,  in  expelling  the  car- 
bon, would  lead  to  infer  that  it  would  be 
most  suitable  for  the  removal  of  phos- 
phorus, and  sulphur  also. 

Mr.  Thompson,  of  Newcastle-on-Tyne, 
England,  has  patented  an  improved  fur- 
nace. The  nature  of  the  invention  con- 
sists of  two  parts.  First,  the  construc- 
tion and  working  of  the  furnace.  Sec- 
ond, the  application  of  the  gases  genera- 
ted in  the  furnace  to  subsequent  useful 
purposes. 

The  body  of  the  furuace,  is  constructed 
somewhat  in  the  ordinary  manner  ;  the 
top  of  it  is  of  a  dome  shape,  and  sur- 
mounted by  a  throat,  the  upper  end  of 
which  can  be  closed  by  iron  plate,  which  is 
intended  to  fit  as  air-tight  as  practicable, 
and  when  removed,  it  is  through  this 
aperture  that  the  furnace  is  charged. 
Above  the  dome,  and  around  the  throat, 
is  the  circular  tunnel  or  chamber ;  it  com- 
municates by  the  apertures  or  short  flues, 
with  the  body  of  the  furnace  in  the  upper 
part  of  the  dome ;  from  this  tunnel,  upon 
opposite  sides  of  the  furnace,  proceed 
vertical  pipes  ;  these  are  intended  to  carry 
off  the  gases  ;  two  steam  pipes  at  their 
lower  ends  communicate  with  a  steam 
boiler  behind  the  furnace,  from  which 
the  steam  is  supplied  :  the  steam  pipes 
pass  upwards  into  the  centre  of  the  ver- 
tical pipes,  and  their  ends  terminate  in  a 
number  of  steam  jets,  arranged  so  as  to 
produce  the  best  effects  of  exhaustion ;  the 
tuyers  are  arranged  in  the  usual  manner 


and  intended  to  supply  air  to  the  furnace 
by  draught,  either  in  a  cold  or  hot  state. 
The  exhaust  pipes  are  about  eighteen 
inches  in  diameter,  and  the  diameter  of 
the  steam  pipes  is  about  four  inches.  The 
steam  jets  being  in  action,  they  cause  an 
exhausting  action  in  the  pipes,  thereby 
drawing  the  gases  generated  in  the  furnace 
through  the  short  flues  and  tunnel,  and  ef- 
fecting the  necessary  working  of  the  fur- 
naee.  The  lid  is  lifted  from  its  seat  oc- 
casionally, for  the  purpose  of  charging 
the  furnace,  but  this  is  to  be  done  as  sel- 
dom as  possible,  as  at  these  times  the  ex- 
hausting action  of  the  steam  jets  is  to  be 
stopped,  and  the  consequent  working  of 
the  furnace  suspended.  This  method, 
therefore,  is  to  do  away  with  the  blower, 
and  use  exhaust  by  steam  as  a  substitute. 

The  second  improvement  is,  the  em- 
ploying the  gases  generated  in  the  fur- 
nace, in  the  above  described  operation, 
to  subsequent  useful  purposes,  as  heating 
the  refinery  and  other  furnaces,  or  genera- 
ting steam  in  steam  boilers  ;  to  effect  this, 
the  vertical  pipes  are  dispensed  with,  and 
the  gasos  generated  are  carried  by  a  pipe 
from  the  tunnel  to  the  furnace  where 
they  are  to  be  employed.  The  steam  jets 
or  other  exhausting  means  are  then  em- 
ployed in  the  exit  or  chimney  from  this 
furnace,  instead  of  the  smelting  furnace, 
as  above. 

The  following  is  the  comparative  power 
of  a  few  different  metals,  to  sustain 
weights  by  suspension,  according  to  Mr. 
Kennie's  experiments,  in  bars  one  quar- 
ter of  an  inch  square  : 

lbs. 

A  cast-iron  bar,  hor.  sustained 1166 

A  ditto,  vertical 1218 

A  cast  6teel  bar  previously  tilted 8391 

A  blister-steel  bar,  reduced  by  hammering    8322 

A  shear-steel  bar,  ditto 7977 

A  Swedish  iron  ditto,  ditto 4504 

An  English  iron  ditto,  ditto 3492 

A  hard  gun-metal  bar 2273 

A  wrought-copper  bar 2112 

A  cast-copper  ditto 1192 

A  fine  yellow  brass  bar 1123 

A  cast-tin  bar 296 

A  cast-lead  bar 114 

Pennsylvania  is  the  largest  iron  manu- 
facturing State ;  it  does  not  manufacture 
of  late  years  as  much  as  previously,  owing 
to  the  low  price  of  imported  iron.  The 
following  statistics  are  taken  from  the 
Scientific  American : — 

It  appears  that  out  of  62  counties  which 
the  State  embraced  at  the  date  of  the  last 
report,  45  contain  iron  works,  and  9  of 
the  remaining  17  contain  abundance  of 
iron  and  coal — though,  owing  to  the  ab- 


IKO] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


275 


sence  of  any  cheap  road  to  market,  they 
yet  remain  untouched — leaving  only  8 
counties  in  the  State  not  adapted  to  the 
manufacture  of  iron. 

There  are  304  blast  furnaces  and  bloom- 
eries  in  the  State,  with  an  invested  capi- 
tal of  $12,921,576  ;  their  present  capacity 
is  for  the  making  of  550,959  tons  per  an- 
num ;  in  1847,  they  made  389,350  tons ; 
in  1849,  253,370  tons;  in  1850,  their  pro- 
bable make  is  estimated  at  198,813  tons. 
Of  the  above  furnaces  57  use  anthracite 
coal;  have  a  capital  of  $3,221,000,  and  a 
present  capacity  for  making  221,400  tons  ; 
in  1847,  they  made  151,881  tons;  in  1849, 
109,168  tons,  and  the  estimated  product 
of  1850  is  81,351  tons.  The  furnaces 
using  bituminous  coal  are  7  in  number, 
with  a  capital  of  $223,000,  and  a  present 
capacity  tor  making  12,600  tons.  In  1847, 
they  made  7,800  tons  ;  in  1849,  4,900 
tons  ;  in  1850,  the  make  will  probably  be 
3,900  tons.  Four  furnaces  use  coke,  have 
a  capital  of  $800,000,  and  a  present  ca- 
pacity for  making  12,600  tons,  per  an- 
num; in  1847,  they  made  10,000  tons. 
Eighty-five  are  charcoal  hot  blast  furna- 
ces, with  an  investment  of  capital  of  $6,- 
478,500,  and  a  capacity  for  making  130,- 
705  tons  per  annum.  The  make  of  1847 
was  94,519;  1849,  58,302;  in  1850,  it  will 
be  42,555.  The  charcoal  cold  blast  fur- 
naces number  145,  with  a  capital  of  $5,- 
170,376,  and  a  capacity  for  making  173,- 
654  tons  per  annum.  The  make  of  1847, 
was  125,155;  1849,  80,655;  in  1850,  it 
will  be  70,727.  There  are  6  bloomeries, 
with  a  capital  of  $28,700,  and  a  capacity 
for  producing  600  tons  per  annum.  The 
product  for  1847  was  545;  1848,  335; 
probable  product  of  1850,  280.  The  esti- 
mate for  1850,  is  obtained  by  deducting 
from  the  product  of  1849  the  amount 
made  by  such  furnaces  as  are  now  idle. 
Of  the  298  furnaces  in  the  State,  149  or 
exactly  one-half  are  in  blast  this  year, 
and  of  these  about  one-third  are  making 
no  preparations  to  blow  during  the  next 
yaar.  The  estimate  for  1850  shows  a  de- 
crease of  190,537  since  1847,  or  49  per 
cent,  in  three  years.  Should  there  be  no 
change  in  the  aspect  of  affairs,  the  make 
of  1851  will  not  exceed  100,000  tons. 

The  number  of  forges  and  rolling  mills 
in  the  State  is  200,  with  a  capital  of  $7,- 
580,500,  with  402  forge  fires,  and  43.6 
puddling  furnaces,  and  a  capacity  to 
make  224,650  tons  per  annum.  Their  ac- 
tual make  for  1847  was  202,727  tons,  and 
1S49,  136,853  tons.  Of  the  above  there 
are  121  charcoal  forges,  with  an  invest- 
ment of  capital  amounting  to  $2,026,300. 


These  forges  have  402  fires,  with  a  capa- 
city of  125  tons  per  fire,  per  annum,  or  a 
total  of  50,250  tons.  In  1847,  they  made 
39,997  tons,  and  in  1849,  28,495  tons. 
The  rolling  mills  number  79,  with  a  capi- 
tal of  $5,554,200.  They  contain  436  pud- 
dling furnaces,  which,  at  400  tons  per 
furnace,  gives  a  total  capacity  of  174,400 
tons  per  annum.  Their  make  in  1847, 
was  163,760  tons;  and  in  1849,  108,358 
tons. 

There  are  606  nail  machines  in  the 
State,  the  annual  product  of  which  is 
606,000  kegs,  or  30,300  tons  ;  being  an 
average  of  1,000  kegs,  of  100  lbs.  each,  to 
a  single  machine.  There  are  13  works 
engaged  in  the  conversion  of  iron  into 
steel,  making  annually  6,078  tons.  Five 
of  these  works  are  in  Philadelphia,  six 
in  Pittsburg,  one  in  Lancaster,  and  one 
in  York.  The  whole  number  of  iron 
works  in  the  State  is  504,  with  a  capital 
of  $20,502,076  invested  in  lands  and  ma- 
chinery, employing  immediately  30,103 
men,  and  13,562  horses,  besides  11,513 
laborers  not  in  the  pay  of  the  iron  mas- 
ters, but  directly  dependent  on  the  iron 
works  for  support ;  making  a  total  of  41,- 
616  men.  Allowing  five  persons  to  each 
laborer,  and  we  have  as  the  population 
dependent  on  the  iron  work,  208,080,  or 
about  one-tenth  of  the  population  of  the 
State. 

In  1847,  the  consumption  of  fuel  in  all 
the  iron  works  of  the  State  was  483,000 
tons  of  anthracite  coal,  at  an  average 
value  of  $3  per  ton,  making  $1,448,000  ; 
9,007,000  bushels  of  bituminous  coal,  at  5 
cents  per  bushel,  making  $450,380;  and 
1,490,252  cords  of  wood,  at  $2  per  cord, 
$2,980,504.  Thus  giving  the  total  cost  of 
fuel  $4,879,884. 

To  show  how  cheaply  iron  is  obtained, 
and  how  the  mechanical  skill  and  labor 
expended  upon  it  totally  overshadow  the 
original  price,  a  number  of  the  British 
Quarterly  Keview,  of  1847,  gave  the  fol- 
lowing curious  and  instructive  calcula- 
tion :— 

Bar  iron  worth  £1  sterling  is  worth 
when  worked  into 

£       «. 

Horse-shoes  2  10 

Table  knives 86    0 

Needles 71    0 

Penknife  blades 657    0 

Polished  buttons  and  buckles 897    0 

Balance  springs  of  watches 50,000    0 

Cast  iron  worth  £1  sterling  is  worth 
when  converted  into 

£ 

Ordinary  machinery 4 

Larger  ornamental  work 45 


276 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[iBO 


Buckles  and  Berlin  work £600 

Neck  chains 1,386 

Shirt  buttons 5,896 

Thirty  one  pounds  of  iron  have  been 
made  into  wire  upwards  of  111  miles  in 
length,  and  so  fine  was  the  fabric,  that  a 
part  was  converted,  in  lieu  of  horse  hair, 
into  a  barrister's  wig.  The  process  fol- 
lowed to  effect  this  extraordinary  tenui- 
ty consists  of  heating  the  iron  and  pass- 
ing it  through  rollers  of  8  inches  diame- 
ter going  at  the  rate  of  400  revolutions 
per  minute  down  to  No.  4  on  the  wire 
gauge.  It  is  afterwards  drawn  cold,  at 
Birmingham,  down  to  38  on  the  same 
gauge,  and  so  on  till  it  attains  the  above 
length  in  miles. 

Of  the  quantity  of  iron  manufactured 
in  Great  Britain,  in  1843,  South  Wales 
produced  279i  thousand  tons ;  Stafford- 
shire, 219!  ;  Shropshire,  8H :  Scotland, 
37i ;  Yorkshire,  33  ;  Derbyshire,  22i  ; 
and  North  Wales,  25. 

It  is  well  known  that  it  is  most  difficult 
to  keep  iron  from  oxidating  or  rusting  on 
the  surface ;  various  plans  have  been 
adopted  to  accomplish  the  object  of  pro- 
tecting the  surface  even  in  a  slight  de- 
gree. Some  of  these  modes  consisted  in 
coating  the  surface ;  in  others,  it  extend- 
ed to  an  alloying  of  the  melted  mass. 
One  method  consists  in  the  addition  of 
pig  iron,  when  in  a  state  of  fusion,  of 
from  2  to  10  per  cent,  of  copper,  tin, 
nickel,  or  antimony,  by  which  addition, 
the  iron  is  rendered  more  malleable  and 
less  subject  to  oxidation.  A  second  me- 
thod consists  in  the  giving  to  the  iron  a 
coating  of  steel,  or  rather  a  species  of 
iron  containing  less  carbon  and  of  course 
approaching  to  steel.  This  is  effected  by 
the  addition  of  one  part  of  blister  steel  to 
four  parts  of  molten  cast  iron,  and  then 
adding  scrap  iron  to  the  mass,  until  an 
iron  rod  is  no  longer  rendered  brittle  by 
being  dipped  in  the  mixture.  With  this 
compound,  common  iron  is  coated  in  the 
same  manner  as  pursued  in  the  case  of 
covering  iron  with  brass  ;  but  various 
methods  are  pursued,  according  to  the 
size  and  nature  of  the  article  to  be  coated  ; 
where  it  is  at  the  end  of  a  bar  of  iron, 
such  as  an  axle,  and  is  to  be  of  a  particular 
form,  this  form  may  be  given  to  the  cru- 
cible, thereby  making  It  a  mould,  and 
when  in  a  state  of  perfect  fusion,  the 
iron,  either  previously  heated  or  cold,  is 
to  be  immersed  in  the  melted  mass,  and 
when  it  is  perceived  that  the  mass  is  per- 
fectly fluid,  then  the  fire  may  be  with- 
drawn, or  the  crucible  be  allowed  to  cool 
by  any  available  means ;  but  when  the 


iron  to  be  coated  is  immersed  cold,  the 
melted  mass  is  immediately  congealed, 
but  it  must  be  permitted  to  remain  in  the 
crucible  till  it  again  becomes  fluid,  and 
then  it  should  be  allowed  to  cool.  If  the 
whole  is  allowed  to  cool  slowly,  it  is  then 
soft,  and  may  be  turned  in  the  lathe,  and 
afterwards  hardened  by  heating  it  and 
cooling  it  suddenly  in  the  usual  manner ; 
but  in  this  case  care  must  be  taken,  as 
the  coating  and  the  iron  have  different 
powers  of  contracting.  If  the  coated 
parts  were  suddenly  immersed  in  water, 
it  would  certainly  crack,  the  uncoated 
part  must  therefore  be  immersed  up  to 
the  coated  part,  when  the  conducting 
power  of  the  iron  will  cool  the  coating 
sufficiently  quick  to  insure  a  proper  hard- 
ness. 

A  third  method  of  preventing  oxida- 
tion, is  case-hardening  the  metal,  by  the 
use  of  ferrocyanide  of  sodium,  calcium  or 
barium. 

In  order  to  apply  the  ferrocyanide,  an 
alkaline  bath,  formed  with  carbonate  of 
soda,  or  other  alkali  is  used.  This  bath 
may  be  a  crucible  or  large  basin  built  in 
the  brickwork  of  the  furnace,  which 
should  be  a  reverberatory  furnace,  and 
previous  to  being  used,  should  be  raised 
to  a  white  heat ;  the  iron  to  be  case-har- 
dened requires  to  be  previously  heated 
to  nearly  a  red-heat,  and  then  immersed 
in  the  bath,  and  there  raised  to  a  heat 
sufficiently  high,  after  which  it  must  be 
immediately  immersed  in  the  ferrocya- 
nide previously  fused  in  another  vessel ; 
but  it  the  quantity  of  iron  to  be  case-har- 
dened is  small,  it  would  not  be  advisable 
to  fuse  the  ferrocyanide  (as  it  is  very 
soon  decomposed),  but  immediately  on 
taking  it  out  of  the  bath  it  must  be 
sprinkled  with  the  ferrocyanide  ;  should 
ferrocyanide  of  potassium  be  used,  it  is 
found  that  the  alkaline  bath  prevents  ef- 
fectively the  corroding  of  the  iron. 

A  fourth  scheme  consists  of  a  method 
of  coating  copper,  or  the  alloys  of  copper 
or  iron,  with  platinum.  Platinum  is  dis- 
solved in  aqua  rcgia,  and  the  iridium 
which  remains  undissolved  as  a  black 
powder,  separated  by  filtration,  then  eva- 
porated to  dryness,  and  when  cold  a 
quantity  of  caustic  potass,  equal  in  weight 
to  the  metallic  platinum  employed  is  to 
be  dissolved  in  water,  and  poured  on  the 
chloride  of  platinum.  This  will  precipi- 
tate the  platinum  of  an  impure  yellow  co- 
lor ;  a  quantity  of  solution  of  oxalic  acid 
equal  to  the  weight  of  the  metallic  plati- 
num, is  now  to  be  added  without  pouring 
off  the  solution  which  remains  on  the 


ivo] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


277 


precipitate  ;  the  solution  is  then  to  be 
boiled  till  the  precipitate  is  entirely  dis- 
solved j  a  small  quantity  of  iridium  will 
still  remain,  which,  together  with  any 
other  impurities,  must  be  separated  by 
nitration ;  caustic  potass  equal  to  twice 
the  weight  of  the  metallic  platinum  is  to 
be  dissolved  in  water  and  added  to  the 
above.  The  solution  is  now  ready  for 
platinizing  the  copper  or  iron  article 
which  is  to  be  coated  with  platinum. 
The  article  to  be  coated  is  to  be  put  in  a 
vessel. 

Iron  in  its  pure  state  is  malleable,  and 
it  is  a  combination  of  carbon  with  iron 
which  produces  cast-iron.  In  addition  to 
carbon,  the  cast-iron  in  this  country  con- 
tains silica,  lime,  magnesia,  alumina,  oc- 
casionally some  of  the  phosphates  and 
other  admixtures ;  but  iron  made  from 
magnetic  ores  is  much  purer.  The 
strength  of  cast-iron  depends  upon  its 
freedom  from  impurities,  and  upon  the 
proportion  of  carbon  it  contains.  The 
strongest  cast-iron  contains  about  three 
per  cent,  of  carbon,  or,  according  to  Mr. 
Charles  May,  when  the  carbon  is  in  the 
smallest  proportion  that  produces  fluidi- 
ty ;  a  larger  proportion  tends  to  make  the 
iron  soft  and  weak,  and  a  smaller  hard 
and  brittle.  Mr.  Glynn,  in  his  evidence 
before  the  Strength  of  Iron  Committee,  in 
London,  states,  that  the  strongest  iron 
generally  shows  a  clear  gray,  or  slightly 
mottled  fracture,  and  he  considers  that 
the  color  indicates  the  combination  of 
carbon  with  iron  which  produces  the 
greatest  strength.  Mr.  Stirling  states, 
that  while  color  is  admissible  as  a  test  of 
strength,  it  is  not  so  of  chemical  consti- 
tution, for  though  dark  colored  iron  is 
usually  brittle,  yet  black  iron  when  chil- 
led becomes  white,  although  it  must  be 
supposed  to  contain  the  same  quantity  of 
carbon  ;  hence,  as  a  general  rule,  he  con- 
cludes that  color  indicates  the  treatment 
to  which  iron  has  been  subjected,  and  in 
some  cases  only  the  quantity  of  carbon. 
Mr.  May  coincides  in  considering  the 
question  of  strength  to  be  very  much  re- 
ducible to  the  quantity  of  carbon  con- 
tained in  the  iron,  as  some  of  the  tender- 
est  iron  skilfully  treated  will  produce 
some  of  the  strongest  eastings.  Messrs. 
Stephenson  and  Stirling  mention  that  the 
fluidity  of  Berlin  iron  is  due  to  the  pre- 
sence of  arsenic,  and  the  latter  has  ob- 
served that  manganese  mixed  artificially 
with  cast-iron,  closes  the  grain,  and  is  an 
improvement  both  to  cast-iron  and  steel. 
On  wrought  iron  the  effect  of  manganese 
is  stated  to  be  to  give  it  the  hot-short 


property,  while  cold-short  is  produced  by 
the  presence  of  a  small  quantity  of  phos- 
phorus ;  and  the  admixture  of  arsenic 
renders  wrought  iron  hard  and  brittle. 

Iron  GuNsi  Pig-iron  of  gray  color 
should  be  melted  in  an  air-furnace  with 
an  intense  and  rapid  fire,  for  iron  guns  ; 
but  an  alloy  of  copper  and.  tin  is  used  for 
brass  guns.  The  first  are  used  on  ship- 
board and  the  latter  for  field  artillery, 
with  a  bush  of  copper,  as  less  fusible  by 
firing,  for  the  touch-hole. 

The  solid  casting  is  then  bored  by  the 
revolution  of  the  gun,  with  an  apparatus 
and  steam  power.  A  24-pounder  of  iron 
is  10  ft.  long,  and  weighs  52  cwt.  with  a 
bore  of  5-824  inches,  a  ball  of  5-547 
inches  and  8  lbs.  of  powder.  A  24-brasa 
pounder  weighs  50  cwt.  An  iron  6-poun 
der  weighs  24  cwt.  and  is  9  ft.  long. 

IVORY,  is  the  tusk  or  tooth  of  defence 
of  the  male  elephant.  It  is  an  interme- 
diate substance,  between  bone  and  horn, 
not  capable  of  being  softened  by  fire,  nor 
so  hard  and  brittle  as  bone.  Sometimes 
it  is  an  enormous  size,  weighing  nearly 
200  lbs.  It  is  of  a  yellowish,  brownish, 
and  sometimes  a  dark  brown  color  on  the 
outside,  internally  white,  hollow  towards 
the  root,  and  so  far  as  was  inserted  into 
the  jaw,  of  a  blackish  brown  color. 

It  is  used  for  making  ornamental  uten- 
sils, mathematical  instruments,  cases, 
boxes,  balls,  combs,  knife-handles,  dice, 
and  to  vs. 

Guillot  obtained  from  100  parts  of 
ivory,  24  gelatine,  64  phosphate  of  lime, 
and  0-1  carbonate  of  lime. 

Ivory  is  restored  in  color,  by  covering 
it  with  quick-lime  and  pouring  vinegar 
on  this.  After  24  hours  rub  it  with  alum- 
powder.  The  best  ivory  comes  from 
Ceylon. 

Ivory  is  very  apt  to  take  a  yellow- 
brown  tint  by  exposure  to  air.  It  may  be 
whitened  or  bleached,  by  rubbing  it  first 
with  pounded  pumice  stone  and  water, 
then  placing  it  moist  under  a  glass  shade 
luted  to  the  sole  at  the  bottorii,  and  ex- 
posing it  to  sunshine.  The  sunbeams 
without  the  shade  would  be  apt  to  occa- 
sion fissures  in  the  ivory.  The  moist 
rubbing  and  exposure  may  be  repeated 
several  times. 

For  etching  ivory,  a  ground  made  by 
the  following  recipe  is  to  be  applied  to  the 
polished  surface  : — Take  of  pure  white 
wax,  and  transparent  tears  of  mastic, 
each  one  ounce ;  asphalt,  half  an  ounce. 
The  mastic  and  asphalt  having  been 
separately  reduced  to  fine  powder,  and 
the  wax  'being  melted  in  an  earthenware 


278 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[rvo 


vessel  over  the  fire,  the  mastic  is  to  be 
first  slowly  strewed  in  and  dissolved  by 
stirring;  and  then  the  asphalt  in  like 
manner.  This  compound  is  to  be  poured 
out  into  lukewarm  water,  well  kneaded, 
as  it  cools,  by  the  hand,  into  rolls  or  balls 
about  one  inch  in  diameter.  These  should 
be  kept  wrapped  round  with  taffety.  If 
white  resin  be  substituted  for  the  mastic, 
a  cheaper  composition  will  be  obtained, 
which  answers  nearly  as  well ;  2  oz. 
asphalt,  1  oz.  resin,  k  oz.  white  wax, 
being  good  proportions.  Callot's  etch- 
ing ground  for  copper  plates,  is  made  by 
dissolving  with  heat  4  oz.  of  mastic  in 
4  oz.  of  very  fine  linseed  oil ;  filtering 
the  varnish  through  a  rag,  and  bottling  it 
for  use. 

Either  of  the  two  first  grounds  being 
applied  to  the  ivory,  the  figured  design 
is  to  be  traced  through  it  in  the  usual 
way,  a  ledge  of  wax  is  to  be  applied,  and 
the  surface  is  to  be  then  covered  with 
strong  sulphuric  acid.  The  effect  comes 
better  out  with  the  aid  of  a  little  heat ; 
and  by  replacing  the  acid,  as  it  becomes 
dilute  by  absorption  of  moisture,  with 
concentrated  oil  of  vitriol.  Simple  wax 
may  be  employed  instead  of  the  copper- 
plate engraver's  ground;  and  strong 
muriatic  acid  instead  of  sulphuric.  If 
an  acid  solution  of  silver  or  gold  be  used 
for  etching,  the  design  will  become  purple 
or  black,  on  exposure  to  sunshine.  The 
wax  may  be  washed  away  with  oil  of  tur- 
pentine. Acid  nitrate  of  silver  affords 
the  easiest  means  of  tracing  permanent 
black  lines  upon  ivory. 

Ivory  may  be  dyed  by  using  the  follow- 
ing prescriptions : — 

1.  Black  dye. — If  the  ivory  be  laid  for 
several  hours  in  a  dilute  solution  of 
neutral  nitrate  of  pure  silver,  with  access 
of  light,  it  will  assume  a  black  color,  hav- 
ing a  slightly  green  cast.  A  still  finer 
and  deeper  black  may  be  obtained  by 
boiling  the  ivory  for  some  time  in  a 
strained  decoction  of  logwood,  and  then 
steeping  it  in  a  solution  of  red  sulphate 
or  red  acetate  of  iron. 

2.  Blue  dye. — When  ivory  is  kept  im- 
mersed for  a  longer  or  shorter  time  in  a 
dilute  solution  of  sulphate  of  indigo  (part- 
ly saturated  with  potash),  it  assumes  a 
blue  tint  of  greater  or  less  intensity. 

3.  Green. dye. — This  is  given  by  dipping 
blued  ivory  for  alittle  while  in  solution  of 
nitro-muriate  of  tin,  and  then  in  a  hot 
decoction  of  fustic. 

4.  TeUowdye  is  given  by  impregnating 
the  ivory  first  with  the  above  tin  mor- 
dant, and  then  digesting  it  with  heat  in  a 


strained  decoction  of  fustic.    The  color 

E asses  into  orange,  if  some  Brazil  wood 
as  been  mixed  with  the  fustic.  A  very 
fine  unchangeable  yellow  may  be  com- 
municated to  ivory  by  steeping  it  18  or 
24  hours  in  a  strong  solution  of  the 
neutral  chromate  of  potash,  and  then 
plunging  it  for  some  time  in  a  boiling  hot 
solution  of  acetate  of  lead. 

5.  Bed  dye  may  be  given  by  imbuing 
the  ivory  first  with  the  tin  mordant,  then 
plunging  it  in  a  bath  of  Brazil  wood, 
cochineal,  or  a  mixture  of  the  two.  Lac 
dye  may  be  used  with  still  more  advan- 
tage, to  produce  a  scarlet  tint.  It*  the 
scarlet  ivory  be  plunged  for  a  little  in  a 
solution  of  potash,  it  will  become  cherry 
red. 

6.  Violet  dye  is  given  in  the  logwood 
bath  to  ivory  previously  mordanted  for  a 
short  time  with  solution  of  tin.  When 
the  bath  becomes  exhausted,  it  imparts  a 
lilach  hue.  Violet  ivory  is  changed  to 
purple-red  by  steeping  it  a  little  while  in 
water  containing  a  few  drops  of  nitro- 
muriatic  acid. 

With  regard  to  dyeing  ivory,  it  may  in 
general  be  observed,  that  the  colors  pene- 
trate better  before  the  surface  is  polished 
than  afterwards.  Should  any  dark  spots 
appear,  they  may  be  cleared  up  by  rub- 
bing them  with  chalk ;  after  which  the 
ivory  should  be  dyed  once  more  to  pro- 
duce perfect  uniformity  of  shade.  On 
taking  it  out  of  the  boiling  hot  dye  bath, 
it  ought  to  be  immediately  plunged  into 
cold  water,  to  prevent  the  chance  of  fis- 
sures being  caused  by  the  heat. 

Madame  Bouvier  (of  Paris)  adopts  the 
following  process  (patented)  for  working 
in  plastic  ivory.  Take  the  waste  turnings 
of  ivory,  bone,  horn,  &c,  and  steep 
them  in  a  waste  acid  solution.  Nearly  all 
the  acids  will  serve  for  this  purpose,  but 
the  following  are  preferable :  muriatic, 
nitric,  tartaric,  acetic,  citric,  and  oxalic, 
also  phosphate  of  lime.  The  solution  is 
placed  in  a  water  bath  at  a  temperatue  of 
35°  to  40°  C,  (95°  to  105°  Fahr.,)  in 
order  to  obtain  complete  liquefaction. 
It  is  then  passed  through  fine  muslin,  and 
about  one  fourth  the  quantity  of  ivory 
gelatine  is  next  added  to  absorb  the  sol- 
vent. When  the  paste  is  well  prepared, 
the  excess  of  liquid,  and  any  foreign 
gases,  are  removed  by  means  of  the  air 
pump :  it  thus  become  homogeneous, 
menibranous,  and  very  close.  In  this 
state  it  would  be  difficult  to  run  it  for 
use  ;  for  which  purpose  it  must  be  dis- 
solved in  copal  or  lac  varnish,  and  in  this 
state  it  may  be  run  into  moulds.    When 


jar] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


270 


the  paste  is  in  the  moulds,  it  may  be  made 
to  undergo  pressure,  to  expel  the  air,  and 
prevent  the  formation  of  air  bubbles  in 
the  interior.  Coloring  matters  may  be 
added  to  the  paste. 

M.  Charriere  of  Paris  renders  the  ivory 
which  he  works  into  shapes,  flexible  by 
steeping  it  in  hydrochloric  acid.  Either 
strong  or  diluted  with  water,  the  ivory 
becomes  flexible,  elastic,  and  yellow.  As 
it  dries  it  becomes  hard  again.  The 
flexibility  is  however  restored  by  wetting 
the  ivory  with  a  piece  of  linen. 

loory  Black  is  made  by  exposing  ivory 
and  bone-shavings  in  an  iron  cylinder, 
at  a  red  heat,  allowing  the  effluvia  to  rise 
through  a  pipe.  It  does  not  differ  from 
bone  black,  being  carbon  in  a  very  fine 
state. 

JACK,  is  the  name  of  a  very  powerful 
machine  for  raising  great  weights.  Its 
ordinary  power  is  5  tons,  or  200  times  the 
force  of  man  applied  to  the  handle.  The 
better  sort  are  supplied  with  a  ratchet, 
to  prevent  their  running  back. 

Jack  is  also  the  name  of  a  kitchen- 
machine  for  cooking,  and  the  moving 
power  is  either  a  weight  or  the  smoke 
and  rarefied  air  of  a  chimney.  It  has  a 
worm,  or  endless  screw,  with  a  main- 
wheel  of  60  teeth,  a  worm-wheel  of  30, 
and  a  pinion- wheel  of  15. 

This  smoke  jack  is  used  for  the  same 
purpose  as  the  common  jack,  and  is  so 
called  because  it  appears  to  be  moved  by 
the  smoke  of  the  fire.  It  is  in  fact  moved 
by  the  ascending  current  of  rarefied  air, 
which  acts  on  a  fan  properly  placed  in 
the  chimney.  The  motion  may  be  ob- 
tained as  above,  or  sometimes  spiral  flyers 
coiled  about  a  vertical  axis  are  employed, 
but  more  frequently  a  vertical  wheel  with 
oblique  leaves  like  the  sails  of  a  wind- 
mill. 

JACQUAED.  (St$  Addenda.) 

JADE,  the  true  lapis  nephriticits,  be- 
longs to  the  siliceous  order  of  minerals, 
as  it  gives  fire  with  steel,  and  is  semi- 
pellucid,  like  flint;  it  does  not  harden  in 
fire,  but  melts,  in  the  focus  of  a  burning 
lens,  into  a  transparent  green  glass,  with 
some  bubbles. 

It  contains  -47  silex,  -38  carbonate  of 
magnesia,  -04  alumine,  *02  carbonate  of 
lime,  and  '09  iron. 

Its  spec,  gravity  is  from  2-950  to  3-389. 

The  semitransparency,  hardness,  and 
specific  gravity,  are  the  characters  by 
which  the  lapis  nephriticvs  may  be  dis- 
tinguished from  other  stones. 

JAMBS.  In  architecture,  the  side  or 
vertical  pieces  of  any  opening  in  a  wall 


which  bear  the  piece  that  discharges  the 
superincumbent  weight  of  such  wall. 

JAMESONITE.  A  mineral  named 
after  Professor  Jameson.  It  occurs 
crystallized  and  massive  :  it  consists  of 
sulphur,  lead,  and  antimonv. 

JAPANNING.  The  art  of  covering 
paper,  wood,  or  metal  with  a  thick  coat 
of  a  hard  brilliant  varnish  :  it  originated 
in  Japan,  whence  articles  so  prepared 
were  first  brought  to  Europe.  The  mate- 
rial, if  of  wood  or  papier-machee,  is  first 
sized,  polished,  and  varnished ;  it  is  then 
colored  or  painted  in  various  devices, 
and  afterwards  covered  with  a  highly 
transparent  varnish  or  lacquer,  which  is 
ultimately  dried  at  a  high  temperature, 
and  carefullv  polished. 

JAPANNED  TEA-  TEA  YS,  were 
made  by  Clay,  by  uniting  sheets  of  paper 
with  wheaten  flour  and  glue  boiled  to- 
gether. They  were  then  rubbed  with 
towels,  from  the  centre  to  the  edges,  and 
dried  in  a  stove  before  another  sheet  was 
laid  on. 

JAPAN,  for  Tin  Ware.— In  6  oz.  of 
oil  of  lavender  dissolve  2  oz.  of  copal  and 
1  dr.  of  camphor,  and  mix  with  8  oz.  of 
oil  of  turpentine. 

JAPAN  PAINTING,  is  effected  by 
colors  prepared  in  varnish.  It  is  finished 
with  a  coating  of  seed-lac  varnish,  made 
of  3  oz.  of  clean  seed-lac,  dissolved  in  a 
pint  of  rectified  spirits  of  wine.  This  is 
laid  on  by  single  coats,  with  the  brush, 
and  each  separately  dried  to  the  number 
of  five  or  six  coats.  It  is  subsequently 
polished  with  a  rag  dipped  in  powdered 
rotten-stone,  and  finished  with  oil.  In 
white  grounds,  fine  putty  or  whiting 
should  be  used. 

JAPAN  WAX.  Under  this  name  dif- 
ferent kinds  of  white  wax  are  met  with, 
the  origin  of  which  are  a  Japan  plant, 
Rhus  Succedanea.  It  is  softer,  more 
brittle,  and  fatty,  than  beeswax,  easily 
kneaded,  and  melts  between  40°  and  42" 
C.  It  contains  twice  as  much  oxygen  as 
beeswax,  and  has  a  different  composition, 
consisting  of  palmitic  acid,  united  with 
oxide  of  glyceryle.  It  is  easily  bleached 
with  nitric  acid'. 

JAEGON.  A  hard  gem  brought  from 
the  East  Indies,  in  the  form  of  thin 
plates,  which  appear  to  be  split  from 
pebbles.  They  are  of  different  colors, 
white,  black,  yellow,  and  brown,  about  as 
hard  as  sapphire ;  and  as  they  have  a 
great  resemblance  to  the  diamond,  they 
are  substituted  instead  of  it  in  jeweller's 
work.  In  this  stone,  Klaproth  discovered 
the  earth  called  zircon. 


280 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


KAL 


JASPER,  an  opaque  flint,  which  re-  j 
sembles  dry  clay.     It  is  capable  of  a  fine 
polish,  and  its  color  is  generally  reddish,  ! 
or  green,  or  striped  ;  but  it  is  also  found  [ 
blue,  gray,  or  whitish.   Its  specific  gravi- 
ty  is  from  2-58  to  2*778. 

It  is  infusible   alone  with  the  blow- 
pipe ;  but  it  melts  with  borax  or  micro-  \ 
cosmic  salt,   without  any  effervescence,  j 
Fire  increases  its  hardness. 

It  is  composed  of  siliceous  earth,  united 
to  al umine  very  full  of  iron.  Daubenton 
mentions  15  varieties. 

JELLY,  VEGETABLE,  of  ripe  cur- 
rants and  other  berries,  is  a  compound  of  i 
mucilage  and  acid,  which  loses  its  power  j 
of  gelatinizing  by  prolonged  ebullition. 

JELLY,  ANIMAL.  {See  Gelatine, 
Glue,  and  Isinglass.) 

JET,  a  species  of  pitch-coal  or  glance- 
coal,  which,  being  found  abundantly  in  a 
beautiful  compact  form,  in  the  valley  of 
Hers,  arrondissement  of  Pamiers,  depart- 
ment of  the  Arriege,  has  been  worked  up 
extensely  there  from  time  immemorial, 
into  a  multitude  of  ornamental  articles. 
"With  this  black  lignite,  buttons,  crosses, 
rosaries,  necklaces,  ear-drops,  bracelets, 
waist-buckles,  &c,  are  made,  which  were 
at  one  time  much  worn  by  ladies  for 
mourning  dresses.  The  greater  number 
of  these  ornaments  are  fashioned  upon 
grindstones  which  turn  in  a  horizontal 
direction,  and  are  kept  continually  wet  • 
others  are  turned  at  the  lathe,  or  shaped 
by  files. 

In  England,  about  40  years  ago,  this 
manufacture  employed  from  1000  to  1200 
operatives;  at  present  it  gives  bread  to 
only  60.  This  falling  off  may  be  ascribed 
to  the  successful  imitation  of  the  jet 
articles  by  those  of  black  glass,  which  are 
equally  beautiful,  and  not  nearly  so  apt  to 
lose  their  polish  by  use. 

JET  D'EAU.  A  fountain  which  throws 
up  water  to  some  height  in  the  air.  Ac- 
cording to  the  theory  of  hydrostatics,  the 
velocity  with  which  "water  issues  from  an 
orifice  is  equal  to  that  which  would  be 
acquired  by  a  heavy  body  in  falling 
through  a  height  equal  to  the  difference 
between  the  levels  of  the  orifice  and  the 
fountain  head ;  whence,  if  the  resistance 
of  the  air  and  other  impediments  were 
removed,  the  height  of  the  jet  would  be 
equal  to  that  of  the  surface  of  the  reser- 
voir. Among  the  causes  which  prevent 
the  jet  from  obtaining  the  height  which 
theory  assigns  to  it,  the  following  are  the 
principal :  1.  The  resistance  of  the  air, 
which  is  proportional  nearly  to  the  square 
of  the  velocity.  2.  The  friction  against  the 


sides  of  the  pipe  and  the  orifL-s  through 
which  the  water  issues.  3.  The  velocity  of 
the  particles  diminishing  at  every  instant 
as  they  ascend,  the  lower  particles  of  the 
ascending  column  press  against  those 
next  above  them ;  and  the  pressure  being 
by  the  nature  of  fluids  communicated  in 
all  directions,  the  consequence  is,  that 
the  column  is  enlarged  and  proportion- 
ally shortened.  4.  The  water  at  the  top 
of  the  jet  does  not  fall  off  instantaneously 
when  its  velocity  is  destroyed ;  it  rests 
for  a  moment  at" the  top  of  the  column, 
where  its  weight  opposes  an  obstacle  to 
the  particles  next  succeeding,  which  re- 
tards their  velocity,  and  this  retardation 
is  communicated  to  the  whole  column. 
This  last  obstacle  may  be  avoided  by 
slightly  inclining  the  jet  from  the  verti- 
cal ;  and  it  is  found  by  experience  that  a 
jet  so  inclined  plays  higher  than  one  quite 
upright,  though  the  effect  is  thereby 
rendered  less  pleasing.  It  is  necessary 
that  the  diameter  of  the  adjutage  or  ori- 
fice be  considerably  less  than  that  of  the 
pipe.  (See  Demgutier's  Experimental  Phi- 
losophy •  Mariotte,  Mouvement  des  Eaux.) 

JOGGLE  JOINTS.  The  joints  of 
stones  or  other  masses  indented  in  such 
a  way  that  the  adjacent  stones  fitting  into 
the  indentations  are  prevented  from  be- 
ing pushed  away  from  each  other  by  any 
force  perpendicular  to  the  pressures  by 
which  they  are  thus  held  together. 

JOGGLE  PICA.  In  architecture  a 
truss-post  whose  shoulders  and  sockets 
receive  the  lower  end  of  the  struts. 

JUJUBE.  The  fruit  of  the  Ehamnus 
zizyphus :  it  resembles  a  small  plum,  and 
is  occasionally  used  as s  a  sweetmeat. 
What  is  sold  under  the  name  of  jujube 
paste  professes  to  be  the  dried  jelly  of  this 
fruit,  but  is,  in  fact,  a  mixture  of  gum 
arabic  and  sugar  slightly  colored. 

JUNIPER  BERRIES.  The  fruit  of 
the  Juniperus  communis.  They  are  used 
in  medicine  as  a  diuretic ;  but  their  prin- 
cipal consumption  is  in  flavoring  gin. 
When  distilled  with  water  they  yield  an 
essential  oil,  upon  which  their  peculiar 
flavor  depends.  The  resin  of  this  tree  is 
called  juniper  gum  or  sandarach,  and  is 
occasionally  used  in  varnishes.  "When 
powdered  it  is  used  under  the  name  of 
pounce,  to  prevent  ink  sinking  into  paper 
from  which  writing  has  been  erased. 

KALI,  a  maritime  plant,  from  the 
ashes  of  which  a  considerable  quantity  of 
soda  is  obtained  by  lixiviation.  By  boil- 
ing the  plant  in  water,  and  evaporating 
the  decoction,  a  considerable  quantity  cf 
sea-salt  may  be  obtained. 


kee] 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


281 


The  word  Kali,  and  Alkali  originally, 
had  a  similar  meaning.  The  latter  term 
is  now  applied  to  a  class  of  bodies  having 
peculiar  properties,  while  the  term  kali  is 
mostly  confined  to  potash,  the  most  active 
of  the  class  of  alkalies.  The  metal  pot- 
assium is  sometimes  called  kalium,  and 
the  symbol  is  always  written  with  the  in- 
itial letter  K. 

KAOLIN,  porcelain  earth,  is  an  earthy, 
pure  white,  grayish  or  milk  white  sub- 
stance, easily  pulverized,  and  mixed  with 
particles  of  quartz  and  feldspar.  It  is  the 
most  important  material  for  making  por- 
celain. Beds  of  pretty  pure  Kaolin  have 
been  found  in  the  neighborhood  of 
Lake  Champlain,  and  scattered  through 
the  New-England  states  and  that  of  New- 
York,  in  the  valleys  of  the  primary  dis- 
tricts. It  is  clay  in  its  pure  and  most 
original  form,  and  is  the  prototype  of  all 
other  clays.  Kaolin  is  produced  by  the 
action  of  the  atmosphere  upon  certain 
minerals  belonging  to  the  feldspar  class, 
as  spodumene  and  porcelain  spar.  Be- 
sides the  silicate  of  alumina  (pure  clay) 
of  the  feldspar,  porcelain  also  contains  un- 
decomposed  debris  of  rocks,  silicates  of 
magnesia  and  lime,  and  free  silicic  acid. 
These  impurities  are  sometimes  as  much 
as  1 6  per  cent.  Out  of  31  analyses  made  by 
Brogniart  and  Malaguti,  18  consisted  of 
alumina  and  silica  in  equivalent  propor- 
tions, the  remainder  containing  an  excess 
of  silica.  In  100  parts  various  samples 
contained  the  following  ingredients  : — 


Knolin  from — 
According  tu — 

St.  Yrieiuc. 
Berthier. 

Pmmui. 

Fnclis. 

Halle. 
Bley. 

Silica 

47-09 

36-41 

1-56 

2-94 

12*66 

43-65 
35-93 

0-88 
1-00 

1S-50 

3962 
45-00 

Magnesia 

3-32 
0-07 

'6:19 
10- 

Oxide  of  Iron 

Oxide  of  Manganese.. 

The  decomposition  of  the  feldspar  out 
of  granite  affords  a  very  good  Kaolin  or 
China  Clay. 

KEEL.  The  principal  piece  of  timber 
of  a  ship,  usually  first  laid  on  the  blocks 
in  building.  If  we  compare  the  body  of 
a  ship  to  the  human  skeleton,  the  keel 
seems  to  resemble  the  backbone,  and  the 
timbers  the  ribs.  It  is  generally  com- 
posed of  several  thick  pieces  of  wood 
placed  lengthways,  which,  after  being 
scarfed  together,  are  bolted  and  clenched 
upon  the  upper  side.    Keelage  signifies  I 


the  duty  paid  by  a  ship  on  coming  into 
port. 

The  keel  is  generally  elm,  except  the 
after-piece,  which,  on  account  of  its  being 
often  wet  and  dry,  is  sometimes  oak, 
especially  when  the  ship  is  expected  to 
be  a  great  while  in  building.  The  num- 
ber of  pieces  in  the  keel  is  not  very  ma- 
terial, so  that  it  gives  good  shift  to  the 
keelson  and  the  mainmast.  The  keel  is 
scarfed  with  a  hook  in  the  middle,  which 
should  lay  very  close,  it  being  designed 
on  purpose  to  bear  the  strain  of  calking 
the  butts,  that  the  bolt  in  the  scarf  may 
not  be  strained.  The  keel  should  not  be 
tapered  much,  either  forward  or  aft  at 
the  upper  part,  and  from  thence  it  is  to 
be  bearded  away  at  the  lower  edge  ;  for, 
when  the  dead-wood  is  trimmed,  espe- 
cially abaft,  being  frequently  very  thin, 
it  is  with  much  difficulty  that  the  dead- 
wood  can  be  securely  bolted. 

The  speed  of  a  vessel  does  not  depend 
so  much  upon  the  form  of  the  bow  as  it 
does  on  the  depth  to  which  it  is  im- 
mersed in  the  water.  In  the  case  of  a 
frigate  drawing  17  feet  water,  and  ano- 
ther frigate  of  the  same  burthen  drawing 
11  feet,  the  last  will  have  a  body  of  six 
feet  less  fluid  to  penetrate,  to  make  her 
hold  a  good  wind,  while  the  first  has  six 
feet  perpendicular  depth  of  her  hull  de- 
pressed, being  about  one-third  of  her 
real  size.  Therefore,  she  has  a  body  of 
water  to  displace,  and  to  force  herself 
through,  equal  to  the  difference  between 
11  and  17.  The  resistance  of  the  fluid 
also  increases  in  proportion  to  the  depth. 
Vessels  in  the  coal-trade  draw  one-third 
less  water  than  any  other  of  British  con- 
struction ;  yet,  when  employed  as  trans- 
ports, they  sail  as  fast  as  any  others ; 
and,  before  the  wind,  in  ballast,  or  half 
loaded,  frequently  beat  the  royal  navy. 
When  closed  hauled  on  a  wind  they  drop 
to  leeward  ;  but,  if  they  were  furnished 
with  sliding  keels,  they  would  be  superior 
to  all  the  other  English  vessels.  The 
Dutch  have  vessels  built  almost  flat,  but 
all  these  have  lee-boards,  by  the  assistance 
of  which  they  sail  as  fast  as  any  that  navi- 
gate the  North  Sea. 

Ships,  or  vessels  of  the  larger  classes, 
should  always  be  so  constructed  as  to 
sail  on,  or  nearly  on  an  even  keel, — that 
is,  so  that  when  the  ship  is  trimmed  for 
sailing,  she  should  have  her  keel  parallel 
to  the  surface  of  the  water  ;  therefore, 
as_  much  as  the  effort  of  the  wind  on  the 
sails  and  mast,  in  forcing  the  ship 
through  the  water,  has  a  constant  ten- 
dency   to    depress    the    bow,    so    much 


282 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[kel 


should  the  ship  be  properly  trimmed  at 
the  stem. 

A  sharp-huilt  ship  sinks  under  its  car- 
go so  fast,  that  by  the  time  it  comes  to 
its  bearings,  it  is  frequently  not  loaded. 
Those  having  flat  and  long  floors,  on  the 
other  hand,  sink  slowly ;  and  after  hav- 
ing taken  in  the  quantity  they  measure, 
will  have,  frequently,  plenty  of  room, 
and  remain  high  out  of  the  water.  The 
only  objection  to  the  latter  is,  the  unfit- 
ness of  a  flat-floored  vessel  to  hold  a 
good  wind,  but  this  difficulty  is  removed 
by  the  adoption  of  sliding"  heels.  The 
same  principle,  which  causes  flat-floored 
vessels  to  sail  faster  before  the  wind,  to 
carry  a  larger  cargo,  and  draw  less  water, 
operates  with  equal  force  in  rendering 
them  easy  at  anchor.  Their  form,  with 
the  fulness  of  their  body  fore  and  aft, 
enables  them  to  rise  and  fall,  according 
to  the  lift  of  the  sea,  while  sharp  and 
clean-built  ships  pitch  with  the  utmost 
violence,  frequently  with  such  force  as 
to  endanger  the  masts  ;  to  say  nothing  of 
the  strain  which  the  tremendous  jerks 
give  the  hull  and  the  injury  of  the  an- 
chors and  cables. 

The  use  of  sliding  keels  is  known,  by 
actual  experience,  to  be  of  the  greatest 
importance.  In  fresh  breezes,  or  in  light 
winds,  it  is  totally  immaterial  how  much 
sail  is  set,  or  how  it  is  disposed  ;  since 
the  act  of  raising  or  lowering  the  keels 
will  immediately  counteract  the  inconve- 
nience that  might  otherwise  arise  from 
carrying  too  much  sail,  either  forward  or 
aft.  The  most  trifling  practice  will  ren- 
der the  navigators  perfectly  acquainted 
with  their  use,  and  the  easy  steerage  of 
this  ship  will  convince  him  of  their  ad- 
vantage. In  a  gale  of  wind  it  is  neces- 
sary tli at  the  main  and  fore-keels  should 
be  hauled  close  up,  and  the  stern-keel  let 
down  to  such  depth  as  shall  be  found 
necessary  to  make  the  vessel  steer  per- 
fectly easy. 

KELP.  A  common  term  for  sea-weed 
or  vraic,  which  consists  of  different  spe- 
cies of  Fucus  (varec).  In  a  strict  sense, 
the  term  kelp  is  confined  to  the  produce 
of  sea-weeds  when  burned,  which  con- 
sists of  alkaline  ashes  used  in  the  manu- 
facture of  glass  and  soap.  It  has  been 
recently  found,  however,  that  the  alkali 
required  for  these  purposes  can  be  ob- 
tained more  abundantly  from  sea-salt, 
and  kelp  is  at  present  chiefly  used  as  a 
manure.  For  this  purpose  it  is  eagerly 
sought  after  by  all  farmers  on  the  sea- 
coast,  and  especially  by  those  who  have 
dry  soils,  the  salt  contained  in  tho  kelp 


being  a  powerful  absorbent  of  moisture 
from  the  atmosphere.  It  has  lately  ac- 
quired much  importance  as  a  source  of 
iodine. 

The  species  used  in  the  manufacture 
of  this  article  grow  attached  to  rocks, 
between  high  and  low  water  mark.  On 
the  Scottish  coast  it  is  cut  close  to  the 
rocks,  during  the  summer  season,  and 
spread,  and  turned  to  dry.  It  is  then 
stacked  and  sheltered,  till  covered  with 
white  saline  efflorescence,  and  is  then 
ready  for  burning,  in  a  round  pit  or  kiln, 
lined  with  brick  or  stone,  about  2  ft. 
wide,  8  to  18  long,  and  from  2  to  3  deep. 
The  bottom  is  covered  with  brush,  upon 
which  a  little  dried  sea-weed  is  scatter- 
ed, and  fire  is  applied  at  one  extremity  ; 
the  sea-weed  is  now  thrown  on  gradu- 
ally, as  fast  as  the  combustion  reaches 
the  surface.  After  the  whole  is  burnt, 
the  mass  gradually  softens,  beginning  at 
the  sides,  when  it  should  be  slowly  stir- 
red up  with  a  heated  iron  bar,  and  in- 
corporated till  it  acquires  a  semi-fluid 
consistence.  This  part  of  the  process  re- 
quires considerable  dexterity ;  and,  if 
the  mass  continues  dry,  a  little  common 
salt  should  be  thrown  on  it  as  a  flux. 
When  cold  it  is  broken  up,  and  is  ready 
for  sale. 

Kelp  contains  but  2  or  3  per  cent,  of 
carbonate  of  soda,  while  Spanish  barilla 
often  contains  20  or  30.  One  of  the  pro- 
ducts is  iodine. 

The  use  of  soda,  in  general,  is  the  same 
with  that  of  potash,  but  it  is  indispensa- 
ble in  making  plate  and  ground  glass  and 
hard  soaps,  and  consumed  in  immense 
quantities  by  soap-boilers,  bleachers,  and 
glass-makers. 

It  is  well  known  that  the  shores  of  the 
sea,  and  salt-marshes,  as  well  as  the 
margins  of  interior  salt-lakes  and  sa- 
lines, and,  in  general,  all  places  to  which 
water  holding  salt  gains  access,  are  in- 
habited by  peculiar  plants.  In  these 
maritime  plants,  soda  replaces  the  pot- 
ash, which  is  always  present  in  plants 
growing  in  ordinary  situations,  and  if 
they  are  removed  to  a  distance  from  the 
sea-shore,  they  gradually  lose  their  soda, 
and  acquire  potash  in  its  stead.  The 
barilla  obtained  in  France  from  the  sali- 
cornia  annua  yields  14  or  15  per  cent,  of 
soda. 

The  Highland  Society  of  Scotland  has 
published  the  following  account  of  the 
manufacture  of  115  tons  of  kelp  in  Harris. 
It  was  from  cut- ware  of  two  years'  growth, 
in  equal  parts  of  lady-ware,  which  grows 
between  the  spring  and  neap  high  tides ; 


ker] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


283 


hell-ware,  between  high  and  low  neap 
tides  ;  black-ware,  low  water,  spring  and 
neap.  It  is  cut  with  a  strong  reaping- 
hook.  Sand  and  mud  is  washed  off,  and 
it  is  spread  by  day,  and  cocked  by  night. 
Then  put  into  large  cocks,  and  left  to 
heat  for  six  or  ei^ht  days.  It  is  burnt 
on  a  dry  day,  and  a  good  breeze.  The 
kilns  are  of  hard  stones,  with  turf  out- 
side, from  15  to  18  feet  long,  2i  ft,  broad 
and  2  feet  high.  Straw  or  heather  is  laid 
over  this,  set  on  fire,  and  dry- ware  added 
on  the  top  by  degrees  till  the  whole  is  in 
ashes.  If  it  cakes,  it  must  be  raked. 
When  all  is  burned,  it  has  the  appear- 
ance of  a  semi-vitrified  solid.  It  is  then 
broken  into  large  lumps,  and  kept  cover- 
ed until  it  is  put  up  in  the  cask  for  ship- 
ment. The  following  two  analyses  of 
kelp,  one  from  Cherbourg,  made  by  Gi- 
rardin,  and  the  other  from  Spain,  made 
by  Richardson,  show  it  to  be  made  up 
mainly  of  sulphate  and  chloride  of  potas- 
sium, and  chloride  of  sodium,  or  common 
salt, 

Cherbourg  Spain. 

Sulphate  potash 4254  1585 

Chloride  potassium  . . .  1964  1055 

Chlorifle  sodium 2538  6835 

Carbonate  of  sqda 371  traces 

Sulphate  lime 1-10 

Insoluble  matter -73  .... 

Iodine  compounds  . . .  .traces  .... 

Water 8-  4-00 

10000  10000 

KERASOPHANY.  A  new  art  has 
been  discovered  in  Berlin,  which  consists 
in  making  pictures  of  a  material,  the 
principal  ingredient  of  which  is  wax,  in 
imitation  oi  transparent  ones  made  in 
porcelain.  To  be  seen,  the  picture  must 
be  placed  between  the  observer  and  the 
light.  The  ingredients  used  with  the 
wax  destroy  its'  brittleness,  and  it  with- 
stands a  heat  of  more  than  one  hundred 
and  fifty  degrees  Fahrenheit. 

KERMES.  An  insect  found  in  many 
parts  of  Asia  and  the  south  of  Europe"; 
the  Coccus  ilicis  of  Linnasus.  They  were 
long  taken  for  the  seeds  of  the  tree  on 
which  they  live,  and  hence  called  grains 
of  kermes.  They  are  used  as  a  red  and 
scarlet  dye,  but  very  inferior  to  cochi- 
neal. Previously  to  'the  introduction  of 
cochineal,  by  which  it  is  now  nearly 
wholly  superseded,  kermes  had  been  the 
most  esteemed  drug  for  dyeing  scarlet 
from  a  remote  period  of  antiquity.  Cloths 
dyed  with  kermes  are  of  a  deep-red  co- 
lor ;  and  though  much  inferior  in  bril- 
liancy to  the  scarlet  cloths  dyed  with  real 
Mexican  cochineal,  they  retain  the  color 


better  and  are  less  liable  to  stain.  The 
tapestries  of  Brussels  and  other  parts  of 
Flanders,  which  have  scarcely  lost  any 
thing  of  their  original  brilliancy,  even 
after  a  lapse  of  200  years,  were  all  dyed 
with  kermes. 

The  principal  varieties  of  kermes  are 
the  coccus  quercus,  the  coccus  polonicus,  the 
coccus  fragariai,  and  the  coccus  uva  ursi. 

The  coccus  quercus  insect  lives  in  the 
south  of  Europe  upon  the  kermes  oak. 
The  female  has  no  wings,  is  of  tho  size 
of  a  small  pea,  of  a  brownish-red  color, 
and  is  covered  with  a  whitish  dust. 
From  the  middle  of  May  to  the  middle 
of  June  the  eggs  are  collected,  and  ex- 
posed to  the  vapor  of  vinegar,  to  prevent 
their  incubation.  A  portion  of  eggs  is 
left  upon  the  tree  for  the  maintenance 
of  the  brood.  In  the  department  of 
the  Bouches-du-Rhone,  one-half  of  the 
kermes  crop  is  dried.  It  amounts  an- 
nually to  about  60  quintals  or  cwts.,  and 
is  warehoused  at  Avignon. 

The  kermes  of  Poland,  or  coccus  polo- 
nicus, is  found  upon  the  roots  ot  the 
scleranthus  perennis  and  the  scleran- 
thus  annuus,  in  sandy  soils  of  that 
country  and  the  Ukraine.  This  species 
has  the  same  properties  as  the  preced- 
ing ;  one  pound  of  it,  according  to  Wolfe, 
being  capable  of  dyeing  10  pounds  of 
wool ;  but  Ilermstaedt  could  not  obtain 
a  fine  color,  although  he  employed  five 
times  as  much  of  it  as  of  cochineal.  The 
Turks,  Armenians,  and  Cossacks,  dye 
with  kermes  their  morocco  leather,  cloth, 
silk,  as  well  as  the  manes  and  tails  of 
their  horses. 

The  kermes  called  coccus  fragarice,  is 
found  principally  in  Siberia,  upon  the 
root  of  the  common  strawberry. 

The  coccus  vva  ursi  is  twice  the  size  of 
the  Polish  kermes,  and  dyes  with  alum 
a  fine  red.    It  occurs  in  Russia. 

Kermes  is  found  not  only  upon  the 
lycopodium  complanatum  in  the  Ukraine, 
but  upon  a  great  many  other  plants. 

Good  kermes  is  plump,  of  a  deep-red 
color,  of  an  agreeable  smell,  and  a  rough 
and  pungent  taste.  Its  coloring  matter 
is  soluble  in  water  and  alcohol ;  it  be- 
comes yellowish  or  brownish  with  acids, 
and  violet  or  crimson  with  alkalies.   Sul- 

Shate  of  iron  blackens  it.  With  alum  it 
yes  a  blood-red ;  with  copperas  an 
agate  gray ;  with  copperas  and  tartar,  a 
lively  gray  ;  with  sulphate  of  copper  and 
tartar,  an  olive  green ;  with  tartar  and 
salt  of  tin,  a  lively  cinnamon  yellow  ; 
with  more  alum  and  tartar,  a  lilach ; 
with  sulphate  of  zinc  and  tartar,  a  violet. 


284 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[L^B 


Scarlet  and  crimson  dyed  with  kermes, 
were  called  grain  colors  ;  and  they  are 
reckoned  to  be  more  durable  than  those 
of  cochineal,  as  is  proved  by  the  bril- 
liancy of  the  old  Brussels  tapestry. 

He'llot  says  that  previous  to  dyeing  in 
the  kermes  bath,  he  threw  a  handful  of 
wool  into  it,  in  order  to  extract  a  black- 
ish matter,  which  would  have  tarnished 
the  color.  The  red  caps  of  the  Levant 
are  dyed  at  Orleans  with  equal  parts  cf 
kermes  and  madder  ;  and  occasionally 
with  the  addition  of  some  Brazil  wood. 

Cochineal  and  lac-dye  have  now  nearly 
superseded  the  use  of  kermes  as  a  tinc- 
torial substance,  in  England. 

Kermes  Mineral.  A  name  given  by 
the  old  chemists  to  the  hydrosulphuret 
of  antimony,  in  consequence  of  its  red- 
dish color.  It  may  be  obtained  perfectly 
pure,  by  diluting  the  proto-chloride  of 
antimony  with  solution  of  tartaric  acid, 
and  precipitating  the  metal  with  sulphu- 
reted  hydrogen  ;  or  by  exposing  the 
finely  levigated  native  sulphuret  to  a 
boiling  solution  of  carbonate  of  potash 
for  some  time,  and  filtering  the  liquor 
while  boiling  hot.  The  kermes  falls 
down  in  a  brown-red  powder,  as  the 
liquor  cools. 

KETCHUP,  or  CATSUP.  A  liquor 
used  as  a  substitute  for  gravy.  That 
made  from  the  Tomato  and  Mushroom 
is  most  common.  They  can  scarcely  be 
called  judicious  mixtures,  but  rather  an 
incongruous  medley  of  strong  tasting 
substances  and  spices,  such  as  garlic, 
shallot,  horse-radish,  lemon-peel,  beer, 
wine,  mustard,  anchovy,  and  spice. 
Mushroom  catsup  is  usually  made  by  ad- 
ding the  grosser  part  of  the  mushrooms 
beaten  up  into  a  pulp,  to  a  decoction  of 
spice  and  salt — properly,  the  expressed 
juice  of  the  mushroom  should  be  pre- 
served in  spice  liquor. 

KILLAS.  A  name  given  to  clay  slate 
by  Cornish  miners. 

*KILN.  The  various  forms  of  furnaces 
and  stoves,  by  which  strong  heat  may  be 
applied  to  bodies,  are  so  called.  Thus 
there  are  brick  kilus,  lime  kilns,  malt 
kilns,  and  pottery  kilns.  Under  the  head 
of  limestone,  malt,  and  pottery,  differ- 
ent forms  of  kiln  are  noticed. 

KINIC  ACID.  A  peculiar  acid  found 
in  Cinchona  bark  by  Vauquelin. 

KINO.  An  extract  obtained  from  the 
Nauclea  cfamMr,  a  shrub  growing  at  Su- 
matra and  in  the  Islands  of  the  Indian 
Ocean.  It  is  of  a  red  brown  color,  has  a 
styptic  taste,  and  consists  chiefly  of  tan- 


nin.   It  is  only  used  as  an  astringent  in 
medicine. 

KIRSCHWASSER,  is  an  alcoholic 
liquor  by  the  fermentation  and  distilla- 
tion of  bruised  cherries.  In  Switzerland 
and  Germany  it  is  the  morello  cherry 
which  is  used.  When  ripe  it  is  black, 
and  has  an  unusually  large  kernel :  the 
fruit  is  snatched  off  the  trees,  and  all 
kinds  thrown  into  tubs  and  crushed 
cither  by  hand  or  with  a  beater.  These 
materials  are  allowed  to  ferment,  and 
when  this  is  completed  it  is  transferred 
to  a  still  covered  with  verdigris  dust. 
The  whole  is  conducted  in  the  rudest  way 
possible.  The  liquor  has  accordingly  a 
rank  smell,  and  is  injurious  to  health  from 
the  empyreumatic  oil  and  prussic  acid 
it  contains. 

KEY-BOARD.  In  music,  the  series  of 
levers  in  a  keyed  instrument,  as  a  piano- 
forte, organ,  or  harpsichord,  upon  which 
the  ringers  press  to  produce  percussion 
of  the  strings,  or  in  the  organ  the  open- 
ing of  valves.  It  consists  of  short  black 
and  long  white  keys. 

KEYSTONE.  The  middle  voussoir  in 
the  arch  of  a  bridge,  or  the  archstone  in 
the  crown  or  immediately  over  the  centre 
of  the  arch.  The  length  of  the  keystone, 
or  thickness  of  the  archivolt  at  top,  is  al- 
lowed to  be  about  1-1 5th  or  l-16th  of  the 
span  bv  the  best  architects. 

KREASOTE.    See  Creosote. 

KYANIZING.  That  process  of  pre- 
serving vegetable  fibre  recommended  by 
the  late  Mr.  Kyan,  of  New-York.  It  con- 
sisted in  the  complete  soakage  and  pene- 
tration into  the  timber  of  i\  solution  of 
bichloride  of  mercury  (corrosive  subli- 
mate). This  salt  was  proposed  as  a  pro- 
tective agent  against  the  attack  of  dry  rot, 
which  renders  wood  so  utterly  worthless 
after  a  few  years.  It  was  at  one  period 
much  used  in  the  British  navy.  (See 
Wood,  preservation  of) 

LABORATORY.  '  The  workshop  of  a 
chemist.  Some  laboratories  are  intended 
for  private  research,  and  some  for  the 
manufacture  of  chemicals  on  the  large 
scale.  Hence  it  is  almost  impossible  to 
give  a  description  of  the  apparatus  and 
disposition  of  a  laboratory  which  would 
be  generally  true  of  all.  A  manufacturing 
laboratory  necessarily  occupies  a  large 
space,  while  that  of  the  scientific  man  is 
necessarily  limited  to  a  peculiar  line  of 
research.  Those  who  study  in  organic 
chemistry  have  different  arrangements 
from  that  of  the  mineral  analyist. 

A  laboratory  is  furnished  with  a  fixed 


I. AC 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


285 


furnace,  and  sundry  auxiliaries  and  por- 
table furnaces.  It  ought  also  to  contain 
blow-pipes  and  galvanic  troughs,  with 
crucibles,  matresses,  retorts,  flasks,  ves- 
sels, and  bottles  ;  also  a  pestle  and  mor- 
tar, a  vice,  a  lathe,  and  carpenters'  tools  ; 
a  pneumatic  trough,  a  sink  for  water,  ta- 
bles, drawers,  and  shelves ;  with  thermo- 
meters, a  barometer,  pvrometer,  hydro- 
meter, Argand's  lamps,  Wojlaston's  scale, 
weights  and  measures,  &c.  It  requires 
also  a  small  stock  of  tests  and  test-paper, 
and  of  sulphuric,  nitric,  and  acetic  acids; 
with  nitre,  soda,  ammonia,  alcohol,  &c, 
&c. ;  and  especially  pasteboard  and  wire 
masks,  and  a  stout  apron  for  the  stomach 
and  abdomen.  The  cost  varies  from 
$200  to  $2,000. 

The  expense  of  fitting  up  a  laboratory 
to  furnish  articles  of  common  consump- 
tion is  very  small.  The  instruments  in- 
dispensably necessary  are — an  alembic, 
with  a  refrigerator  and  portable  furnace. 
If  the  operator  should  not  choose  to  go 
to  the  expense  of  the  alembic  and  its  ap- 
paratus, a  succedaneum  may  be  found  for 
them  in  a  sand-bath  or  sand-heat,  with 
retorts,  under  suitable  precautions. 

Sand-7ieut  is  usually  formed,  in  the 
large  way,  of  an  oblong  shape,  having 
bricks  and  mortar  for  its  walls,  plates  of 
iron  upon  which  to  lay  the  sand,  and 
around  the  top  a  ledge,  of  about  six  or 
eight  inches  deep,  of  free-stone,  to  retain 
the  sand.  Beneath  the  plates  of  iron  is  a 
wide  flue,  at  the  bottom  of  which  is  an 
non  grating,  upon  which  grating  is  laid 
the  fire.  The  fire  is,  of  course,  when 
kindled,  enclosed  by  a  door,  as  in  other 
furnaces,  at  the  end  of  the  sand-heat ;  a 
flue  communicates  with  a  chimney,  to 
cany  off  the  smoke.  The  sand  is  com- 
monly of  the  depth  of  six  or  eight  inches ; 
but  the  quantity  and  depth  depend  upon 
the  size  of  the  vessels. 

A  retort  is  a  vessel  usually  made  of 
green  or  other  glass,  and  may  be  made  to 
hold  from  half  a  pint  to  eight  or  more 
gallons.  It  has  a  long  narrow  neck, 
which  is  so  bent,  that  when  the  retort  is 
placed  with  its  contents  in  a  sand-bath, 
or  over  a  fire,  it  has  a  gentle  inclination, 
and  will  conduct  whatever  liquid  is  con- 
densed in  it,  into  a  glass  receiver,  which  is 
placed  on  a  bench  beside  the  sand-heat ; 
the  receiver  is  luted  to  the  neck  of  the 
retort,  either  by  a  caoutchouc  skin,  which 
is  the  neatest  way^or  by  some  other  lute. 
A  variety  of  chemical  processes  are  thas 
conducted :  the  vapors  raised  by  the  heat 
being  condensed  in  the  neck  of  the  re- 
tort, and  cooled  down  in  the  receiver, 


(which  is  usually  about  the  size  of  a  re- 
tort,) by  the  large  surface  which  it  pre- 
sents to" the  air.  With  Florence  flasks  and 
bent  tubes  fitted  with  cork  many  opera- 
tions requiring  retorts  maybe  used;  and 
even  small  glass  tubes  may  supplant 
these  latter  in  the  more  delicate  applica- 
tions. 

On  this,  as  on  many  other  subjects, 
more  is  learnt  in  half  an  hour,  by  actual 
inspection,  than  by  half  a  volume  of  de- 
scription. 

There  are  some  very  well-appointed 
laboratories  in  this  country ;  amongst 
others,  that  in  the  Lawrence  Scientific 
School,  Harvard  University,  Cambridge, 
Mass.,  and  those  in  Philadelphia  are  pro- 
minent. 

LAC.     Lac-dye,  is  produced    by  the 

Juncture  of  an"  insect  called  the  Cocus 
iacca,  upon  the  branches  of  several 
plants  as  varieties  of  the  ficus,  rhamnus, 
and  the  croton.  It  is  the  female  insect 
which  punctures  the  twig,  which  then 
becomes  surrounded  with  a  resinous 
juice  which  hardens  and  has  a  crystalline 
fracture.  This  constitutes  the  stick-lac 
of  commerce  ;  it  is  of  a  red  color,  more  or 
less  deep  and  transparent. 

According  to  Franke,  the  constituents 
of  stick-lac  are,  resin,  65-7;  substance  of 
the  lac,  23-2;  coloring  matter,  0-0. 

Seed-lac.  When  the  resinous  concre- 
tion is  taken  off  the  twigs,  coarsely  pound- 
ed, and  triturated  with  water  in  a  mortar, 
the  greater  part  of  the  coloring  matter  is 
dissolved,  and  the  granular  portion  which 
remains,  being  dried  in  the  sun,  consti- 
tutes seed-lac.  It  contains,  of  course,  less 
coloring  matter  than  the  stick-lac,  and  is 
much  less  soluble.  John  found  in  100 
parts  of  it,  resin,  66-7  ;  wax,  1-7;  matter 
of  the  lac,  16-7 ;  bitter  balsamic  matter, 
2*5 ;  coloring  matter,  3-9  ;  dun  yellow  ex- 
tract, 0-4  ;  envelopes  of  insects,  2-1  ;  lac- 
tic acid,  0-0;  salts  of  potash  and  lime, 
1-0 ;  earths,  6-6  ;  loss,  4*2. 

In  India  the  seed-lac  is  put  into  oblong 
bags  of  cotton  cloth,  which  are  held  over 
a  charcoal  fire  by  a  man  at  eacli  end,  and, 
as  soon  as  it  begins  to  melt,  the  bag  is 
twisted  so  as  to  strain  the  liquefied  resin 
through  its  substance,  and  to  make  it 
drop  upon  smooth  stems  of  the  banyan 
tree.  In  this  way,  the  resin  spreads  into 
thin  plates,  and  constitutes  the  substance 
known  in  commerce  by  the  name  of 
shellac. 

The  Pegu  stick  -lac,  being  very  dark- 
colored,  furnishes  a  shellac  of  a  corres- 
ponding deep  hue,  and  therefore  of  infe- 
rior value.    The  palest  and  finest  shel- 


286 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lac 


lac  is  brought  from  the  northern  Circar. 
It  contains  very  little  coloring  matter. 
A  stick-lac  of  an  intermediate  kind  comesv 
from  the  Mysore  country,  which  yields  a 
brilliant  lac-dye  and  a  good  shellac. 

Lac-dye  is  the  watery  iufusion  of  the 
ground  stick-lac,  evaporated  to  dryness, 
and  formed  into  cakes  about  two  inches 
square,  and  half  an  inch  thick.  Dr.  John 
found  it  to  consist  of  coloring  matter,  50 ; 
resin,  25  ;  and  solid  matter,  composed  of 
alumina,  plaster,  chalk,  and  sand,  22. 

Dr.  Macleod,  of  Madras,  prepared  a 
very  superior  lac-dye  from  stick-lack,  by 
digesting  it  in  the  cold  in  a  slightly  alka- 
line decoction  of  the  dried  leaves  of  the 
Memecylon  tinctorium.  This  solution  be- 
ing used  along  with  a  mordant,  consist- 
ing of  a  saturated  solution  of  tin  in  muri- 
atic acid,  was  found  to  dye  woollen  cloth 
of  a  very  brilliant  scarlet  hue. 

The  cakes  of  lac-dye  imported  from  In- 
dia, stamped  with  peculiar  marks  to  de- 
signate their  different  manufacturers,  are 
now  employed  exclusively  in  England  for 
dyeing  scarlet  cloth,   and  are  found  to 

Jield  an  equally  brilliant  color,  and  one 
ass  easily  affected  by  perspiration  than 
that  produced  by  cochineal.  When  the 
lac-dye  was  first  introduced,  sulphuric 
acid  was  the  solvent  applied  to  the  pul- 
verized cakes,  but  as  muriatic  acid  has 
been  found  to  answer  so  much  better,  it 
has  entirely  supplanted  it.  A  good  sol- 
vent  (No.  1)  for  this  dye-stuff  may  be 
prepared  by  dissolving  three  pounds  of 
tin  in  60  pounds  of  muriatic  acid,  of  spe- 
cific gravity  "1'19.  The  proper  mordant 
for  the  cloth  is  made  by  mixing  27  pounds 
of  muriatic  acid  of  sp.  grav.  1-17,  with 
li  pounds  of  nitric  acid  of  1-19  ;  putting 
this  mixture  into  a  salt-glazed  stone  bot- 
tle, and  adding  to  it,  in  small  bits  at  a 
time,  grain  tin,  till  4  pounds  be  dissolved. 
This  solution  (No.  2)  may  be  used  with- 
in twelve  hours  after  it  is  made,  pro- 
vided it  has  become  cold  and  clear.  For 
dyeing,  three  quarters  of  a  pint  of  the 
solvent  (No  1)  is  to  be  poured  upon  each 

?)ound  of  the  pulverized  lac-dye,  and  al- 
owed  to  digest  upon  it  for  six  hours. 
The  cloth,  before  being  subjected  to  the 
dye  bath,  must  be  scoured  in  the  mill 
with  fullers'  earth.  To  dye  100  pounds 
of  pelisse  cloth,  a  tin  boiler  of  300  gallons 
capacity  should  be  filled  nearly  brimful 
with  water,  and  a  fire  kindled  under  it. 
Whenever  the  temperature  rises  to  150° 
Fahr.,  a  handful  of  bran  and  half  a  pint 
of  the  solution  of  tin  (No.  2)  are  to  be 
introduced.  The  froth,  which  rises  as  it 
approaches  ebullition,  must  be  skimmed 


off ;  and  when  the  liquor  boils,  10i 
pounds  of  lac-dye,  previously  mixed 
with  7  pints  of  the  solvent  No.  1,  and  3£ 
pounds  of  solution  of  tin  No.  2,  must  be 
poured  in.  An  instant  afterwards,  104 
pounds  of  tartar,  and  4  pounds  of  ground 
sumach,  both  tied  up  in  a  linen  bag,  are 
to  be  suspended  in  the  boiling  bath  for 
five  minutes.  The  fire  being  now  with- 
drawn, 20  gallons  of  cold  water,  -with  101 
pints  of  solution  of  tin,  being  poured  into 
the  bath,  the  cloth  is  to  be  immersed  in 
it,  moved  about  rapidly  during  ten  mi- 
nutes ;  the  fire  is  to  be  then  rekindled, 
and  the  cloth  winced  more  slowly  through 
the  bath,  which  must  be  made  to  boil  as 
quickly  as  possible,  and  maintained  at 
that  pitch  for  an  hour.  The  cloth  is  to 
be  next  washed  in  the  river ;  and  lastly, 
with  water  only,  in  the  fulling  mill.  The 
above  proportions  of  the  ingredients  pro- 
duce a  brilliant  scarlet  tint,  with  a  slight- 
ly purple  cast.  If  a  more  orange  hue  be 
wanted,  white  Florence  argal  may  be 
used,  instead  of  tartar,  and  some  more 
sumach.  Lac-dye  may  be  substituted  for 
cochineal  in  the 'orange-scarlets;  but  for 
the  more  delicate  pink  shades,  it  does  not 
answer  so  well,  as  the  lustre  is  apt  to  be 
impaired  by  the  large  quantity  of  acid 
necessary  to  dissolve  the  coloring  matter 
of  the  lac. 

Shellac,  by  Mr.  Hatchett's  analysis, 
consists  of  resin,  90~5  ;  coloring  matter, 
0-5;  wax,  4-0;  gluten,  2-8;  loss,  1-8;  in 
100  parts. 

The  resin  may  be  obtained  pure  by 
treating  shellac  'with  cold  alcohol,  and, 
filtering  the  solution  in  order  to  separate" 
a  yellow  gray  pulverulent  matter.  When 
the  alcohol  is  again  distilled  off,  a  brown, 
translucent,  hard,  and  brittle  resin,  of 
specific  gravity  1-139,  remains.  It  melts 
into  a  viscid  mass  with  heat,  and  diffuses 
an  aromatic  odor.  Anhydrous  alcohol 
dissolves  it  in  all  proportions.  Accord- 
ing to  John,  it  consists  of  two  resins,  one 
of  which  dissolves  readily  in  alcohol, 
ether,  the  volatile  and  fat  oils ;  while  the 
other  is  little  soluble  in  cold  alcohol,  and 
is  insoluble  in  ether  and  the  volatile  oils. 
Unverdorben,  however,  has  detected  no 
less  than  four  different  resins,  and  some 
other  substances,  in  shellac.  Shellac  dis- 
solves with  ease  in  dilute  muriatic  and 
acetic  acids  ;  but  not  in  concentrated  sul- 
phuric acid.  The  resin  of  shellac  has  a 
<rreat  tendency  to  combine  with  salifiable 
bases;  as  with  caustic  potash,  which  it 
deprives  of  its  alkaline  taste. 

This  solution,  which  is  of  a  dark  red 
color,  dries  into  a  brilliant,  transparent, 


lac] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


28* 


reddish-brown  mass ;  which  may  be  re- 
dissolved  in  both  water  and  alcohol.  By 
passing  chlorine  in  excess  through  the 
dark-colored  alkaline  solution,  the  Jac- 
resin  is  precipitated  in  a  colorless  state. 
When  this  precipitate  is  washed  and 
dried,  it  forms,  with  alcohol,  an  excellent 
pale-yellow  varnish,  especially  with  the 
addition  of  a  little  turpentine  and  mastic. 

With  the  aid  of  heat,  shellac  dissolves 
readily  in  a  solution  of  borax. 

LACE.  Is  a  species  of  net-work  made 
of  silk,  thread,  *or  cotton,  upon  which 
in  old  times  patterns  were  embroidered 
by  the  needle  after  its  construction.  It  is 
now,  however,  almost  always  formed  du- 
ring the  construction.  The  best  laces  are 
made  at  Mechlin,  Brussels,  Antwerp, 
Ghent,  and  Valenciennes.  In  the  British 
dominions,  at  Nottingham,  and  Limerick. 

The  real  lace,  such  as  was  worn  by  the 
dowagers  of  the  last  century,  is  formed 
principally  of  flax  thread,  and  is  wholly 
worked  by  hand,  not  only  in  the  decora- 
tive parts,  but  in  the  mesh-work  ground 
itself.  The  bobbin-net  of  modern  times 
is  made  of  cotton  thread  ;  the  meshes 
being  made  wholly  by  machinery  ;  and 
the  figured  device  (if  any)  being  effected 
sometimes  by  the  same  machine  and  at 
the  same  time  as  the  ground,  and  some- 
times by  a  kind  of  embroidery  or  tam- 
bour-work. The  silk  net,  such  as  the 
material  of  which  black  veils  are  some- 
times made,  is,  as  its  name  imports,  made 
of  silk  thread,  and  is  formed  by  machine- 
ry very  nearly  on  the  same  principle  as 
bobbin-net. 

At  what  period  and  in  what  country 
this  elegant  material  was  originally  first 
wrought  for  dress  cannot  perhaps  be 
easily  determined.  It  has  been  supposed 
that 'Mary  de  Medici  was  the  first  who 
brought  lace  into  France  from  Venice, 
where,  and  in  the  neighboring  states  of  It- 
aly, lace  seems  to  have  been  long  previous- 
ly worn.  It  is  recorded  that  lace-making 
was  introduced  into  England  by  some 
refugees  from  Flanders,  who  settled  near 
Cranfield,  now  a  village  on  the  west  side 
of  Bedfordshire,  and  adjoining  Bucking- 
hamshire ;and  it  has  been  supposed  that 
the  first  kind  so  made  in  England  was 
that  which  is  called  Brussels  point,  the 
net-work  being  made  by  bone  bobbins  on 
a  pillow,  and  the  pattern  and  sprigs  being 
worked  with  a  needle. 

The  working  of  hand-made  or  "pillow 
lace"  may  be  thus  briefly  described  : 
The  lace-maker  sits  on  a  stool  or  chair, 
and  places  a  hard  cushion  on  her  lap. 
The  desired  pattern  is  sketched  upon  a 


piece  of  parchment,  which  is  then  laid 
down  upon  the  cushion  ;  and  she  inserts 
a  number  of  pins  through  the  parchment 
into  the  cushion,  in  places  determined  by 
the  pattern.  She  is  also  provided  with  a 
number  of  small  bobbins,  on  which 
threads  are  wound  ;  fine  thread  being 
used  for  making  the  meshes  or  net,  and 
a  coarser  kind,  called  gimp  or  (jump,  for 
working  the  device.  The  work  is  begun 
at  the  upper  part  of  the  cushion  by  tying 
together  the  threads  in  pairs,  and  each 
pair  is  attached  to  one  of  the  pins  through 
the  cushion.  The  threads  are  then 
twisted  one  round  another  in  various 
ways,  according  to  the  pattern,  the  bob- 
bins serving  as  handles  as  well  as  for 
store  of  material,  and  the  pins  serving 
as  knots  or  fixed  points,  or  centres,  round 
which  the  threads  may  be  twisted.  The 
pins  inserted  in  the  cushion  at  the  com- 
mencement are  merely  to  hold  the 
threads  ;  but  as  each  little  mesh  is  made 
in  the  progress  of  the  working,  other 

Eins  are  inserted,  to  prevent  the  threads 
•ora  untwisting  ;  and  the  device  on  the 
parchment  shows  where  these  insertions 
are  to  occur. 

The  pillow-made,  or  bone-lace,  which 
formerly  gave  occupation  to  multitudes 
of  women  in  their  own  houses,  has,  in 
the  progress  of  mechanical  invention, 
been  nearly  superseded  by  the  bobbin-net 
lace,  manufactured  at  first  by  hand-ma- 
chines, as  stockings  are  knit  upon  frames, 
but  recently  by  the  power  of  water  or 
steam.  This  elegant  texture  possesses 
all  the  strength  and  regularity  of  the  old 
Buckingham  lace,  and  is  far 'superior  in 
these  respects  to  the  point-net  and  warp 
lace,  which  had  preceded,  and  in  some 
measure  paved  the  way  for  it. 

The  threads  in  bobbin-net  lace  form, 
by  their  intertwisting  and  decussation, 
regular  hexagonal  holes  or  meshes,  of 
which  the  two  opposite  sides,  the  upper 
and  under,  are  directed  along  the  breadth 
of  the  piece,  or  at  right  angles  to  the 
selvage  or  border.  By  the  crossing 
and  twisting  of  the  threads,  the  regu- 
lar six-sided  mesh  is  produced,  and  the 
texture  results  from  the  union  of  three 
separate  sets  of  threads,  of  which  one 
set  proceeds  downwards  in  serpentine 
lines,  a  second  set  proceeds  from  the 
left  to  the  right,  and  a  third  from 
the  right  to  the  left,  both  in  slanting  di- 
rections. These  oblique  threads  twist 
themselves  round  the  vertical  ones,  and 
also  cross  each  other  betwixt  them,  in  a 
peculiar  manner.  In  comparing  bobbin- 
net  with  a  common  web,  the  perpendicu- 


288 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[lac 


lar  threads,  which  arc  parallel  to  the 
border,  may  be  regarded  as  the  warp,  and 
the  two  sets  of  slanting  threads,  as  the 
weft. 

These  warp  threads  are  extended  up 
and  down,  in  the  original  mounting  of 
the  piece,  between  a  top  and  bottom  hori- 
zontal roller  or  beam,  of  which  one  is 
called  the  warp  beam,  and  the  other  the 
lace  beam,  because  the  warp  and  finished 
lace  are  wound  upon  them  respectively. 
These  straight  warp  threads  receive  their 
contortion  "from  the  tension  of  the  weft 
threads  twisted  obliquely  round  them  al- 
ternately to  the  right  and  the  left  hand. 

If  we  pursue  the  path  of  a  weft  thread, 
we  find  it  goes  on  till  it  reaches  the 
outermost  or  last  warp  thread,  which 
it  twists  about ;  not  once,  as  with  the 
others,  but  twice  ;  and  then  returning 
towards  the  other  border,  proceeds  in  a 
reverse  direction.  It  is  by  this  double 
twist,  and  by  the  return  of  the  weft 
threads,  that  the  selvage  is  made. 

The  ordinary  material  cf  bobbin-net  is 
two  cotton  yarns,  of  from  No.  180  to  No. 
250,  twisted  into  one  thread  ;  but  some- 
times strongly  twisted  single  yarn  has 
been  used.  "The  beauty  of  the  fabric  de- 
pends upon  the  quality  of  the  material, 
as  well  as  the  regularity  and  smallness  of 
the  meshes.  The  number  of  warp  threads 
in  a  yard  in  breadth  is  from  600  to  900  ; 
which  is  equivalent  to  from  20  to  30  in  an 
inch.  The  size  of  the  holes  cannot  be 
exactly  inferred  from  that  circumstance, 
as  it  depends  partly  upon  the  oblique 
traction  of  the  th reads.  The  breadth  of 
the  pieces  of  bobbin-net  varies  from 
edgings  of  a  quarter  of  an  inch,  to  webs 
12,  or  even  20  quarters,  that  is,  5  yards 
wide. 

Bobbin-net  lace  is  manufactured  by 
means  of  very  costly  and  complicated 
machines,  called  frames. 

The  bobbin  of  a  net  machine  is  a  curi- 
ous contrivance.  The  cotton  is  wound 
on  to  a  bobbin  or  reel  from  the  skeins  by 
a  winding  machine,  and  thence  trans- 
ferred to  the  little  apparatus  of  the  bob- 
bin-net machine.  This  apparatus  is  so 
minute  that  the  whole  of  it,  inclusive  of 
the  bobbin  on  which  the  cotton  weft 
thread  is  wound,  and  the  carriage  or 
frame  in  which  it  is  placed,  is  not  thicker 
than  the  diameter  of  the  meshes  in  the 
net  to  be  made.  This  thickness  is  often 
not  more  than  the  one-thirtieth  of  an 
inch. 

The  bobbin  consists  of  two  thin  disks  of 
brass  about  an  inch  and  a  half  in  diame- 
ter, laid  face  to  face,  with  a  slight  inter- 


vening space  ;  and  in  this  minute  space 
the  thread  is  wound,  in  quantity  about 
fifty  or  sixty  yards  to  each  bobbin.  The 
bobbin  is  then  fitted  into  a  kind  of  car- 
riage, which  conveys  it  between  the 
threads  of  the  warp,  and  at  the  same 
time  allows  the  thread  to  be  unwound 
from  the  bobbin  :  in  short,  the  carriage 
is  to  the  bobbin  what  the  little  boat  of  a 
shuttle  is  to  the  pin  on  which  the  weft- 
thread  is  wound. 

No  less  than  three  thousand  six  hun- 
dred of  such  bobbins  as  are  here  de- 
scribed are  sometimes  used  in  one  ma- 
chine !  Many  of  the  machines  are  twenty 
quarters  wide — that  is,  fitted  to  the  manu- 
facture of  net  five  yards  in  width  ;  and 
have  twenty  of  these  bobbins  to  the 
inch. 

If  the  arrangement  of  such  a  machine 
be  examined,  it  will  be  seen  that  the  warp- 
threads  are  wound  on  a  beam  in  the  lower 
part  of  the  machine,  from  which  they  as- 
cend to  the  upper  part.  The  warp  is  di- 
vided into  two  parcels  (somewhat  in  the 
same  manner  as  the  warp  of  a  common 
loom  by  the  action  of  the  treadles),  and 
each  parcel  is  susceptible  of  a  reciproca- 
|  ting  motion,  alternately  to  the  right  and 
i  left.  The  weft-threads,  wound  on  the 
bobbins,  are  fastened  each  at  one  end  to 
the  upper  part  of  the  machine  ;  and  the 
bobbins  are  suspended  so  as  to  have  a 
backward  and  forward  motion  between 
the  warp-threads,  like  so  many  clock 
!  pendulums,  being  guided  between  the 
warp-threads  by  a  very  curious  piece  of  ap- 
paratus called  a  "  comb."  The  principle 
of  action,  then,  is  this  : — After  the  bob- 
bins have  been  driven  between  the  re- 
spective warp-threads,  the  warp  is  shifted 
a  little  on  one  side,  so  that,  when  the 
bobbins  return,  they  pass  through  open- 
ings different  from  those  which  they 
traversed  in  the  first  instance  ;  and  by 
this  means  the  weft-thread,  unwinding 
from. each  bobbin  in  the  course  of  its 
movement,  becomes  twisted  around  one 
of  the  warp-threads.  After  this  has  been 
repeated  two  or  three  times,  the  comb 
which  carries  the  bobbins  is  itself  shifted 
to  and  fro  laterally,  by  which  the  bobbins 
are  brought  opposite  to  openings  between 
the  warp  threads  different  from  those  to 
which  they  were  before  opposed.  Herein 
lies  the  whole  principle.  According  as 
the  front  layer  of  warp,  or  the  hinder 
layer,  or  the  comb  carrving  the  bobbins, 
are  shifted  to  and  fro  laterally,  so  does 
the  weft-thread,  as  it  becomes  unwound 
from  the  bobbins,  twist  round  the  warp- 
threads  during  the  passage  of  the  bobbins 


lac] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


289 


across  ;  a  shifting,  in  one  or  other  of 
several  different  ways,  being  effected  im- 
mediately after  each  traverse  of  the  bob- 
bin. After  a  certain  number  of  twist- 
ings  have  been  effected,  a  series  of  points 
become  inserted  between  the  warp- 
threads,  and  temporarily  hold  up  the 
knotted  twists  so  as  to  form  the  meshes 
af  the  net. 

It  has  been  often  said,  and  truly,  that 
the  bobbin-net  machine  is  one  of  the 
most  complicated  which  the  ingenuity  of 
man  has  ever  devised  ;  and  it  may  there- 
fore well  be  supposed  that  nothing  more 
than  the  bare  principle  can  be  here  ex- 
hibited. Perhaps  it  may  assist  the  reader 
•f  we  carry  out  our  former  supposition  a 
tittle  further.  Let  a  series  ot  strings  be 
suspended  from  the  ceiling  in  the  two 
rows,  with  the  lower  ends  of  each  row 
fastened  to  a  horizontal  bar  :  and  let  a 
number  of  small  pendulums  be  suspended 
between  the  strings,  and  enablea  to  os- 
cillate to  and  fro  between  them.  Then, 
if  after  each  traverse  of  the  pendulums 
between  the  stretched  threads,  the  rows, 
one  or  both,  of  threads  be  shifted  a  little 
on  one  side,  so  that  the  pendulums  may 
return  through  openings  different  from 
those  which  they  before  traversed,  we 
should  have  a  system  of  movements  some- 
what analogous  to  those  in  the  machine  ; 
and  the  strings  by  which  the  pendulums 
were  suspended  would  be  found  to  twist 
round  the  stretched  vertical  strings.  If 
we  further  suppose  that  each  row  of 
strings  ia  capable  of  being  shifted  inde- 
pendent of  the  other,  and  that  the 
pendulum  strings  be  fastened  to  a  shift- 
ing bar  near  the  ceiling,  we  might  imitate 
in  a  rough  way  the  series  of  movements 
by  which  net  is  made. 

Not  only  is  plain  net  made  by  these 
movements  of  the  machine,  but  figured 
net  also.  In  plain  nets,  all  the  bobbins 
are  moved  similarly  at  the  one  time ;  but 
in  fancy  nets,  some  are  stationary ;  some 
pass  between  the  warp  threads,  some  are 
shifted  laterally  to  the  distance  of  one 
mesh,  some  to  the  distance  of  two  or 
three  meshes,  some  move  to  the  right 
and  some  to  the  left.  The  warp-threads 
instead  of  being  divided  into  two  parcels, 
are  divided  into  several,  each  of  which  is 
susceptible  of  the  lateral  movement  in- 
dependent of  the  others  ;  it  is  by  modi- 
fications of  these  lateral  movements  that 
all  the  numerous  varieties  of  machine 
made  lace  or  net  are  produced. 

A  rack  of  lace  is  a  certain  length  of 
work  counted  perpendicularly,  and  con- 
shes  or  holes.    In 


tains  240  meshes 


13 


perfect 


lace  the  mesh  is  elongated  a  little  in  the 
direction  of  the  selvage.  The  price  of 
labor  in  making  a  rack  20  years  ago  was 
$1,  it  is  now  made  for  two  cents ;  so  great 
has  been  the  improvement  and  economy 
in  the  manufacture,  and  this  reduction  of 
cost  illustrates  well  the  great  capabilities 
of  machinery.  In  Mr.  Waterhouse's  (of 
England)  machine  for  manufacturing 
mechlin-lace,  the  number  of  warp-threads 
in  the  width  alone  is  4,700,  and  a  corres- 
ponding number  of  bobbins  or  weft- 
threads  are  required,  making  a  total  of 
9,400  threads  :  which  represents  the  same 
number  of  bobbins,  and  are  all  kept  in 
motion  at  the  same  time.  In  making 
pillow  lace  it  requires  as  many  hands  as 
there  are  bobbins  :  for  on  the  cushion 
one  hand  must  wait  for  the  other  in  order 
to  obtain  the  register  crossings  of  the 
threads.  Some  idea  may  be  formed  of 
the  intricacy  of  the  machinery  and  the 
ingenuity  displayed  in  the  arrangement. 
Some  of  the  specimens  woven  by  the 
machine  were  26  yards  long  and  4  yards 
wide,  and  had  4  patterns  woven  in  it. 
The  number  of  motions  or  throws  that 
would  be  required  to  produce  a  similar 
piece  of  lace  by  hand  would  amount  to 
not  less  than  2,111.616,000. 

LACKER,  or  LACQUER,  is  a  varnish 
consisting  chiefly  of  a  solution  ofpale 
shell-lac  in  alcohol,  tinged  with  saffron, 
annotto,  or  other  coloring  matters.  The 
following  are  a  few  of  the  formula?  with 
the  proportions : 

Lacker.  {For  metal*  and  wood — a 
golden  color.)  In  5  half-pints  of  alcohol 
dissolve  1  oz.  of  seed-lac,  gum  dragon, 
gamboge,  and  annotto,  also  2  drs.  of  saf- 
fron ;  or,  in  12  oz.  of  alcohol  dissolve  1  lb. 
of  turmeric,  2  oz.  of  annotto,  and  2  oz.  of 
shell-lac  and  juniper  gum  ;  or,  in  2  pints 
and  4  oz.  of  alcohol  dissolve  i  dr.  of  saf- 
fron and  of  extract  of  red  sanders,  1  dr. 
of  gum  dragon,  2  oz.  of  amber  and  of 
gamboge,  and  3  oz.  of  seed-lac ;  or,  in  1 
pint  4  oz.  of  alcohol,  dissolve  6  drs.  of  tur- 
meric and  15  grs.  of  saffron ;  decant,  and 
add  6  drs.  of  gamboge,  2  oz.  of  gum 
elemi  and  of  gum  sandarac,  and  1  oz.  of 
gum  dragon  and  of  seed-lac. 

Lacquer  for  Tin.  Take  8  oz.^  of  am- 
ber, 2  oz.  of  gum-lac,  melt  them  in  sepa- 
rate vessels,  and  mix  them  well  together ; 
then  add  i  lb.  of  drying  linseed-oil.  Into 
a  pint  phial  put  half  a  pint  of  spirits  of 
turpentine,  and  digest  in  it  a  little  saffron ; 
when  the  color  is  extracted,  strain  the  li- 
quor, and  add  gum  tragacanth  and  an- 
notto, finely  powdered,  and  in  small  quan- 
tities at  a  time,  till  the  required  tope  pf 


290 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lak 


color  is  produced ;  then  mix  this  coloring 
matter  with  the  first  compound  before 
prescribed,  and  shake  them  well  together 
till  a  perfect  union  takes  place.  If  this 
varnisli  be  laid  over  silver-leaf  or  tin-foil, 
it  will  be  difficult  to  distinguish  it  by  the 
eye  from  gold.  It  is  by  a  varnish  of  this 
kind  that  leather,  paper,  or  wood,  covered 
with  silver-leaf,  is  made  to  appear  as  if 
it  were  gilded.  The  lacquer  is  also  ap- 
plicable to  tin-plate  articles,  but  small  ar- 
ticles of  finely-polished  brass  are  usually 
coated  with  a  thinner  composition. 

Lacquer  for  Brass  or  Silver.  Take  2 
oz.  of  seed-lac,  2  oz.  yellow  amber,  40  grs. 
dragon's  blood,  30  grs.  saffron,  40  oz. 
spirits  of  wine,  and  digest  on  a  sand- hath. 
Strain  through  a  fine  cloth,  and  cork. 
Clean  and  burnish  the  buttons,  heat  them, 
and  apply  the  lacquer. 

Lac  Spirit  is  made  of  muriatic  acid 
(sp.  gr.  1-19)  60  lbs. ;  tin  3  lbs.,  dissolved. 
It  is  used  in  dyeing  with  lac-dye  ;  or,  it 
may  be  made  of  aquafortis  28  lbs.  and  tin 
4  lbs. ;  dissolved  gradually  and  stirring 
frequently. 

LACTIC  ACID  was  first  discovered  by 
Scheele  in  buttermilk,  in  which  it  is  abun- 
dant. It  also  exists  in  fresh  milk.  It 
does  not  crystallize,  and  forms  with  most 
bases,  except  zinc  and  magnesia,  gum- 
my salts.  It  has  not,  as  yet,  been  turned 
to  any  useful  purpose  in  the  arts. 

LACTOMETER  is  the  name  of  an  in- 
strument for  estimating  the  quality  of 
milk,  called  also  a  Gaiactomtter.  The 
most  convenient  form  of  apparatus  would 
be  a  series  of  glass  tubes  about  1  inch  in 
diameter,  and  12  inches  long,  graduated 
through  a  space  of  10  inches,  two-tenths 
of  an  inch,  having  a  stop-cock  at  the  bot- 
tom, and  suspended  upright  in  a  frame. 
The  average  milk  of  the  cow  being  poured 
in  to  the  height  of  10  inches,  as  soon  as 
the  cream  has  all  separated  at  top,  the 
thickness  of  its  body  may  be  measured 
by  the  scale  ;  and  then  the  skim  milk  may 
be  run  off  below  into  a  hydrometer  glass, 
in  order  to  determine  its  density,  or  rela- 
tive richness  in  caseous  matter. 

LAKES.  Under  this  title  are  compris- 
ed all  those  colors  which  consist  of  a  ve- 
getable dye,  combined  by  precipitation 
with  a  white  earthy  basis,  which  is  usu- 
ally alumina.  The  general  method  of 
preparation  is  to  add  to  the  colored  infu- 
sion a  solution  of  common  alum,  or  rather 
a  solution  of  alum  saturated  with  potash, 
especially  when  the  infusion  has  been 
made  with  the  aid  of  acids.  At  first  only 
a  slight  precipitate  falls,  consisting  of  alu- 
mina and  the  coloring  matter;  but  on 


adding  potash,  a  copious  precipitation  en- 
sues, of  the  alumina  associated  with  the 
dye.  When  the  dyes  are  not  injured,  but 
are  rather  brightened  by  alkalies,  the 
above  process  is  reversed  ;  a  decoction  of 
the  dye-stuff  is  made  with  an  alkaline  li- 
quor, and  when  it  is  filtered,  a  solution  of 
alum  is  poured  into  it.  The  thirdmethod 
is  practicable  only  with  substances  hav- 
ing a  great  affinity  for  subsulphate  of  alu- 
mina ;  it  consists  in  agitating  recently 
precipitated  alumina  with  the  decoction 
of  the  dye. 

Yellow  lakes  are  made  with  a  decoction 
of  Persian  or  French  berries,  to  which 
some  potash  or  soda  is  added  ;  into  the 
mixture  a  solution  of  alum  is  to  be  pour- 
ed as  long  as  any  precipitate  falls.  The 
precipitate  must  be  filtered,  washed,  and 
iormed  into  cakes,  and  dried.  A  lake 
may  be  made  in  the  same  way  with  quer- 
citron, taking  the  precaution  to  purify  the 
decoction  ol  the  dye-stuff  with  butter- 
milk or  glue.  After  filtering  the  lake,  it 
may  be  brightened  with  a  solution  of  tin. 
Annotto  lake  is  formed  by  dissolving  the 
dye-stuff  in  a  weak  alkaline  ley,  and  add- 
ing alum  water  to  the  solution."  Solution 
of  tin  gives  this  lake  a  lemon  yellow  cast ; 
acids  a  reddish  tint. 

Bed  lakes. — The  finest  of  these  is  car- 
mine. 

This  beautiful  pigment  was  accidentally 
discovered  by  a  Franciscan  monk  at  Pisa. 
He  formed  an  extract  of  cochineal  with 
salt  of  tartar,  in  order  to  employ  it  as  a 
medicine,  and  obtained,  on  the  addition 
of  an  acid  to  it,  a  fine  red  precipitate. 
Romberg  published  a  process  for  prepar- 
ing it,  in  1656.  Carmine  is  the  coloring 
matter  of  cochineal,  prepared  by  pre- 
cipitation from  a  decoction  of  the  drug. 
Its  composition  varies  according  to  the 
mode  of  making  it.  The  ordinary  car- 
mine is  prepared  with  alum,  and  consists 
of  carminiitm(see  Cochineal),  a  little  ani- 
mal matter,  alumina,  and  sulphuric  acid. 
See  Carmine. 

Carminated  lake,  called  lake  of  Florence, 
Paris,  or  Vienna.  For  making  this  pig- 
ment, the  liquor  is  usually  employed 
which  is  decanted  from  the  carmine  pro- 
cess. Into  this,  newly  precipitated  alu- 
mina is  put ;  the  mixture  is  stirred,  and 
heated  a  little,  but  not  too  much.  When- 
ever the  alumina  has  absorbed  the  color, 
the  mixture  is  allowed  to  settle,  and  the 
liquor  is  drawn  off. 

Sometimes  alum  is  dissolved  in  the  de- 
coction of  cochineal,  and  potash  is  then 
added,  to  throw  down  the  alumina  in 
i  combination  with  the  coloring  matter; 


lam] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


291 


but  in  this  way  an  indifferent  pigment  is 
obtained.  Occasionally,  solution  of  tin  is 
added,  to  brighten  the  dye. 

A  lake  may  be  obtained  from  kermes, 
in  the  same  way  as  from  cochineal ;  but 
now  it  is  seldom  had  recourse  to. 

Brazil-wood  lakes.  Brazil-wood  is  to 
be  boiled  in. a  proper  quantity  of  water 
for  15  minutes  :  then,  alum  and  solution 
of  tin  being  added,  the  liquor  is  to  be  fil- 
tered, and  a  solution  of  potash  poured  in 
as  long  as  it  occasions  a  precipitate.  This 
is  separated  by  the  filter,  washed  in  pure 
water,  mixed  with  a  little  gum  water,  and 
made  into  cakes.  Or,  the  Brazil-wood 
may  be  boiled  along  with  a  little  vinegar, 
the  decoction  filtered,  alum  and  salt  of 
tin  added,  and  then  potash-ley  poured  in 
to  precipitate  the  lake.  For  1  lb.  of  Bra- 
zil wood,  30  to  40  lbs.  of  water,  and  from 
11  to  2  lbs.  of  alum,  may  be  taken,  in  pro- 
ducing a  deep  red  lake  ;  or  the  same  pro- 
portions with  half  a  pound  of  solution  of 
tin.  If  the  potash  be  added  in  excess, 
the  tint  will  become  violet.  Cream  of 
tartar  occasions  a  brownish  cast. 

Madder  lake.  A  fine  lake  may  be  ob- 
tained from  madder,  by  washing  it  in  cold 
water  as  long  as  it  gives  out  color ;  then 
sprinkling  some  solution  of  tin  over  it, 
and  setting  it  aside  for  some  days.     A 

f;entle  heal  may  also  be  applied.  The  red 
iquor  must  be  then  separated  by  the  fil- 
ter, and  decomposed  by  the  addition  of 
carbonate  of  soda,  when  a  fine  red  preci- 
pitate will  be  obtained.  Or,  the  reddish 
brown  coloring  matter  of  a  decoction  of 
madder  may  be  first  separated  by  acetate 
of  lead,  and  then  the  rose-red  color  with 
alum.  Or,  madder  tied  up  in  a  bag  is 
boiled  in  water ;  to  the  decoction,  alum 
is  added,  and  then  potash.  The  precipi- 
tate should  be  washed  with  boiling  water, 
till  it  ceases  to  tinge  it  yellow  ;  and  it  is 
then  to  be  dried. 

The  following  process  merits  a  pre- 
ference : 

Diffuse  2  pounds  of  ground  madder  in 
4  quarts  of  water,  and  after  a  maceration 
of  10  minutes,  strain  and  squeeze  the 
grounds  in  a  press.  Repeat  this  macera- 
tion, &c,  twice  upon  the  same  portion 
of  madder.  It  will  now  have  a  fine  rose 
color.  It  must  be  mixed  with  5  or  6  lbs. 
of  water  and  half  a  lb.  of  bruised  alum, 
and  heated  upon  a  warm  bath  for  3  or  4 
hours,  with  the  addition  of  water,  as  it 
evaporates,  after  which  the  whole  must 
be  thrown  upon  a  filter  cloth.  The  liquor 
which  passes  is  to  be  filtered  through 
paper,  and  then  precipitated  by  carbo- 
nate of  potash.    If  the  potash  be  added 


in  three  successive  doses,  three  different 
lakes  will  be  obtained,  of  successively  di- 
minishing beauty.  The  precipitates  must 
be  washed  till  the  water  comes  off  color- 
less. 

Blue  lakes  are  hardly  ever  prepared,  as 
indigo,  Prussian  blue,  cobalt  blue,  and 
ultramarine,  answer  every  purpose  of  blue 
pigments. 

Green  lakes  are  made  by  a  mixture  of 
yellow  lakes  with  blue  pigments  ;  but 
chrome  yellows  mixed  with  blues  produce 
almost  all  the  requisite  shades  of  green. 

LAMINABLE  is  said  of  a  metal,  which 
may  be  extended  by  passing  between 
steel  or  hardened  (chilled)  cast-iron  roll- 
ers.   See  Iroii. 

LAMPS  were  first  invented  by  the 
Egyptians,  from  whom  they  passed  to 
Greece  and  Eome.  They  were  made  of 
baked  earth,  iron,  copper,  silver,  gold, 
and  glass. 

Ordinary  lamps  are  only  arrangements 
whereby  materials  (fat)  which  are  fluid 
at  common  temperatures,  as  the  oils,  are 
consumed.  The  first  object  is  to  isolate 
as  much  of  the  oil  as  is  required  for  the 
production  of  a  flame.  The  simplest 
manner  in  which  this  can  be  effected,  is 
that  practised  in  the  night-lights. 

On  a  layer  of  oil  covering  the  surface 
of  the  water  there  swims  a  brass  cup,  at 
the  bottom  of  which  is  a  small  piece  of 
glass  tube,  fitted  tight  by  a  cork.  Al- 
though, before  ignition,  the  oil  rises  in 
the  interior  of  that  tube  above  the  level 
on  the  outside,  yet,  as  the  capillarity  of 
the  tube  is  annihilated  by  the  heat, 
the  fluid  is  actually  depressed.  To  ob- 
viate this,  the  tube  must  be  fixed  so 
far  below  the  surface  of  the  oil,  that  the 
greater  pressure  of  the  oil  without  shall 
overcome  the  depression  within.  In  this 
manner  the  insulated  oil  in  the  other  end 
may  be  ignited,  and  continues  to  burn  by 
itself.  The  conditions  under  which  the 
oil  is  consumed,  so  far  as  the  production 
of  light  is  concerned,  are  most  unfavora- 
ble, although  the  purpose  of  a  night 
lamp  is  fully  answered  ;  for  the  flame  is 
much  too  small  for  producing  light  for 
common  purposes  ;  and,  if  the  size  of  the 
tube  is  increased,  the  oil  will  no  longer 
burn,  and  the  flame  is  too  low  down  to 
lighten  well  the  room.  Both  of  these 
evils,  particularly  the  latter,  are  avoided 
by  the  use  of  wicks.  The  common  kit- 
chen lamp  is  a  slight  improvement  on 
this.  The  following  are  the  essential 
points,  which  it  has  been  the  object  of 
inventors  to  attain,  sometimes  singjv, 
sometimes  several  at  once. 


292 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[lam 


1.  To  select  such,  a  form  (section)  of 
wick,  that  the  quantity  of  decomposed 
oil,  and  the  simultaneous  supply  of  air, 
may  stand  in  the  relation  to  each  other 
that  the  hydrogen  and  carbon  may  be 
consecutively  consumed,  and  consequent- 
ly no  smoke  produced. 

2.  To  make  the  distance  between  the 
burning  part  of  the  wick  and  the  surface 
of  the  oil  as  unchangeable  as  possible,  in 
order  that  as  much  oil  may  be  drawn  up 
at  last  as  at  first. 

3.  To  place  the  reservoir  of  oil  in  such 
a  position  that  the  shadow  shall  occasion 
little  or  no  inconvenience.  The  use  made 
of  the  lamp  Avill  regulate  its  form.  Occa- 
sionally these  cannot  correspond. 

Thus,  the  shadow  of  wall-lamps  is  un- 
important, as  the  lamp  covers  its  shadow ; 
bo  the  shadow  of  a  study-lamp  is  not  a 
fault,  as  it  is  only  used  by  one  person  ; 
yet  still  its  prevention  is  an  improve- 
ment. 

4.  To  throw  the  light,  radiating  from 
the  flame,  by  means  of  collectors  and  re- 
flectors, from  those  parts  where  it  is  of 
little  or  no  service,  in  the  direction  most 
required. 

The  requisites  stated,  under  No.  1,  have 
have  been  complied  with  in  two  ways ; 
first,  by  controlling  the  access  of  air  (the 
quantity  of  air) ;  on  the  other  by  regu- 
lating the  supply,  and  often  by  both  at 
the  same  time.  We  have  reference  to 
that  part  of  the  lamp  called  the  burner. 

When  there  is  much  oil  burned  at  the 
one  point,  the  current  of  air  supplied  on 
the  outside  is  nev^r  sufficient  for  burning 
away  the  oil  completely,  so  as  to  produce 
only  water  and  carbonic  acid ;  on  the 
contrary,  an  amount  of  carbon  is  deposit- 
ed, owing  to  their  not  being  oxygen 
enough  to  burn  it  fully  away  into  carbo- 
nic acid:  the  flame  soots.  This  great 
evil  was  to  a  certain  extent  remedied  by 
the  invention  of  the  Argand  lamp,  called 
after  Mr.  Argand,  who  first  produced  it 
in  1784.  The  principle  on  which  the  su- 
periority of  the  Argand  lamp  depends,  is 
the  admission  of  a  larger  quantity  of  air 
to  the  flame  than  can  be  done  in  the  com- 
mon way. 

This  is  accomplished  by  making  the 
wick  of  a  circular  form,  by  which  means 
the  current  of  air  rushes  through  the  cyl- 
inder on  which  it  is  placed,  with  great 
force,  and  along  with,  that  which  has  ac- 
cess to  the  outside,  excites  the  flame  to 
such  a  degree  that  the  smoke  is  entirely 
consumed  :  thus  both  the  light  and  heat 
are  prodigiously  increased.  The  combus- 
tion being  exceedingly  augmented  by  the 


quantity  of  air  admitted  to  the  flame,  and 
what  in  common  lamps  is  dissipated  in 
smoke  is  here  converted  into  brilliant 
flame.  This  lamp  is  now  very  much  in 
use,  and  is  applied  not  only  to  ordinary 
purposes  of  illumination,  but  also  to  that 
of  a  furnace  for  chemical  operations,  in 
which  it  is  found  to  excel  every  other  con- 
trivance yet  invented.  It  consists  of  two 
parts,  a  reservoir  for  the  oil,  and  the  lamp 
itself.  The  argand  burner  is  made  by 
forming  a  hollow  cylindrical  cavity,  which 
receives  the  oil  from  the  main  body  of  the 
lamp,  and  at  the  same  time  transmits  air 
through  its  axis  or  central  hollow  ;  in  this 
cavity  is  placed  a  circular  wick  attached 
at  bottom  to  a  movable  ring;  this  ring 
may  be  raised  or  depressed  by  rack  and 
pinion  work,  or  more  commcrly  a  screw, 
so  that  the  height  of  the  wick  may  be  va- 
ried to  regulate  the  size  of  the  flame.  On 
the  outside  is  placed  a  glass  chimney, 
which  transmits  a  current  of  air  on  the 
same  principles  as  a  common  smoke  flue. 
When  this  lamp  is  lighted,  the  combus- 
tion is  vivid  and  the  light  intense,  owing 
to  the  free  and  rapid  supply  of  air.  The 
flame  does  not  waver,  and  the  smoke  is 
wholly  consumed.  The  brilliancy  is  in- 
creased if  the  air  be  made  to  impinge  later- 
ally against  the  flame.  This  is  done  by  nar- 
rowing the  glass  chimney  near  the  blaze, 
so  as  to  bend  the  air  inward,  or  by  plac- 
iug  a  metallic  button  over  the  blaze,  so  as 
to  spread  the  internal  current  outward. 

To  avoid  the  shade  occasioned  in  com- 
mon lamps  by  the  reservoirs  for  the  oil 
being  under  the  flame,  various  contriv- 
ances have  been  introduced,  in  which  the 
reservoir  is  placed  at  a  distance  from  the 
flame.  In  the  astral  and  sinumhra  lamps, 
the  principal  of  which  was  invented  by 
Count  Eumford,  the  oil  is  contained  in  a 
horizontal  ring,  having  a  burner  at  the 
centre,  communicating  with  the  ring  by 
two  or  more  tubes  placed  like  rays.  The 
wick  is  placed  a  little  below  the  level  of 
the  flame,  and  from  its  large  surface  af- 
fords a  supply  of  oil  for  many  hours.  A 
small  aperture  is  left  for  the  admission  or 
escape  of  the  air  in  the  upper  part  of  the 
ring.  When  these  lamps  overflow,  it  is 
because  the  ring  is  not  kept  perfectly  hor- 
izontal, or  else  because  the  air  hole  is  ob- 
structed— a  circumstance  which  may  be 
produced  by  filling  the  lamp  too  high  with 
oil. 

In  all  common  lamps  the  oil  box  is 

above,  and  while  it  allows  the  oil  to  flow 

down  upon  the  wick  and  keep  it  moist, 

it  casts  an  objectionable  shadow.    To  ob- 

I  viate  this  the  oil  box  is  placed  in  some 


lam] 


CYCLOPEDIA    OP   THE    USEFUL    ARTS. 


293 


lamps  below,  and  the  oil  lias  to  be  raised ; 
this  involves  ingenious  but  complicated 
apparatus. 

GirarcPs  hydrostatic  lamp  is  constructed 
on  precisely  the  same  principles  as  the  air 
chamber  of  a  fire  engine,  or  similar  to  the 
fountain  of  Hero  (which  see).  The  second 
illustration  given  under  that  article  is  an 
ideal  lamp  of  Girard.  The  air  vessel,  air 
chamber,  and  connecting  tubes  are  closely 
packed  together.  Its  shape  is  inconve- 
nient and  limits  its  extended  use. 

In  1825  Thilorier,  at  Paris,  invented  a 
lamp  in  which  the  principle  of  the  equili- 
brium of  fluid  pressure  is  made  use  of: 
if  two  fluids  of  different  densities  be 
placed  in  tubes  connected  at  the  bottom, 
they  will  balance  each  other  at  different 
heights,  according  to  their  respective  den- 
sities. Thus,  a  column  of  mercury  1  inch 
high,  will  balance  a  column  of  sulphuric 
ether  of  19  inches,  or  a  column  or  oil  14 
inches. 

Thilorier  used  a  solution  of  equal  parts 
of  white  vitriol  and  water,  which  is  11 
times  denser  than  oil.  So  that  10  inches 
of  the  zinc  solution  can  balance  15*7 
inches  oil  in  the  other  tube.  As  the  oil 
diminishes  by  burning,  the  zinc  solution 
exerting  its  pressure  "upon  it  keeps  it  up 
to  the  original  level.  This  lamp  cannot 
well  be  moved  or  carried  about,  without 
fear  of  being  extinguished. 

In  the  mechanical  lamp  it  is  a  pump 
which  is  used  to  raise  the  oil  up.  In  Car- 
eer s  lamp  the  pump  is  worked  by  clock- 
wheel  arrangement.  The  case  for  the 
works  and  space  for  the  supply  of  oil  are 
at  the  foot  ot  the  lamp  :  the  stem  of  the 
lamp  contains  only  the  ascending  tube, 
which  separates  above  over  the  capital 
into  a  forked  appendage  or  crutch,  upon 
which  rests  the  burner  with  its  two  con- 
centric tubes.  The  burner  and  ascending 
tube  form  a  space  connected  with  the  oil 
vessel  by  the  pump.  Three  little  pumps, 
termed  priest  pumps,  are  alternately  act- 
ing, one  being  forcing,  the  second  is 
sucking,  and  the  third  midway  between 
the  two.  Motion  is  obtained  by  a  spring 
wound  up  in  a  case  and  furnished  with 
cogs,  which  act  upon  the  wheel  which 
works  the  pumps.  This  lamp  burns  well, 
but  it  is  costly,  is  liable  to  get  out  of  order, 
and  cannot  always  readily  be  repaired. 

Vapor  lamps  are  those  in  which  the 
fluid  in  the  lamp  is  first  vaporized,  and 
the  heat  thus  produced  while  burning 
tends  to  raise  a  tresh  quantity  of  fluid  up 
in  the  form  of  vapor.  A  little  cup  of 
spirits  of  wine,  or  a  cloth  soaked  with 
the  same,  and  surroui  ding  the  nozzle  of 


the  lamp,  are  the  usual  means  of  vaporiz- 
ing the  liquid,  which  is  usually  one  part  of 
turpentine  mixed  with  4  parts  of  alcohol 
of  90  per  cent. 

Solar  lamps.  The  chief  point  in  the 
construction  of  these  lamps  is  the  man- 
ner in  which  the  air  is  caused  to  impinge 
upon  the  flame  by  the  adaptation  of  a 
metallic  or  glass  cone.  Thi3  admits  of  a 
crude  and  cheap  oil  being  used,  which  in 
other  lamps  would  smoke. 

A  very  beautiful  kind  of  miniature  solar 
lamp,  for  those  who  have  much  writing 
at  night,  is  manufactured  by  Messrs  En- 
dicott  and  Sumner,  N.  Y.  The  light  of 
one  is  equal  to  that  of  six  sperm  candles, 
and  it  can  burn  either  oil  or  lard.  A 
pound  of  lard  lasts  about  twentv  hours. 
The  air  is  admitted  to  the  flame  all ;  ound 
it,  inside  and  out,  thus  supplying  it  with 
plenty  of  oxygen,  consequently  there  is 
no  part  of  the  flame  blue,  but  all  is  a 
bright  white  light. 

Whale  oil  is  so  thick  and  coarse  when 
cold  that  it  does  not  readily  ascend  the 
wick  until  heated. 

Parkers  economic  or  hot  oil  lamp  was 
intended  to  obviate  this,  and  has  the  oil 
vessel  as  a  double  cylinder,  surrounding 
the  upper  part  of  the  chimney.  This  latter 
is  slightly  curved  outwards,  so  as  to  re- 
flect the  heat  upon  the  oil  vessel ;  the  hot 
oil  descends  by  the  arm  to  the  burner.  A 
slide  regulates  and  cuts  off  the  supply,  so 
that  the  oil  vessel  may  be  removed  to  be 
filtered.  Care  must  be  taken  to  fill  the  ves- 
sel with  oil  and  allow  no  air  to  remain,  as 
its  expansion  would  make  the  oil  overflow. 

Camphene  lamps. — Oil  of  turpentine  is 
the  liquid  in  these  lamps.  This  sub- 
stance is  composed  in  100  parts  of  88-4G 
of  carbon  and  11*54  of  hydrogen,  which 
corresponds  to  the  formula  C10H8.  This 
quantity  of  carbon  is  vastly  above  what 
is  found  in  oils,  and  hence  more  air  is 
requisite  to  burn  it  without  sooting. 
This  is  accomplished  by  putting  a  but- 
ton in  the  flame,  and  narrowing  the  glass 
at  the  point  where  the  flame  is  thrown 
out.  Sometimes  the  current  of  air  which 
supplies  the  inner  part  of  the  flame  is 
made  to  pass  through  the  reservoir  of 
turpentine,  which  becomes  heated  10°  or 
15°  above  the  temperature  of  the  sur- 
rounding air. 

A  Platina  lamp  has  been  made  by  Mr. 
Merry  weather,  of  Whitby,  England,  some 
years  since.  If  a  coil  of  small  platina 
wire  be  placed  around  the  wick  of  a 
spirit-lamp,  and  rendered  red  hot,  the 
wire  continues  ignited  for  some  time 
after  the  flame  is  blown  out.    The  lower 


294 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[lam 


part  is  constructed  of  tin,  in  the  body  of 
•which  is  a  reservoir,  large  enough  to 
contain  a  quart  of  alcohol.  The  bottom 
of  the  interior  of  the  reservoir  is  con- 
cave, in  order  that  the  cotton  wick  may 
take  up  the  last  drop  of  the  spirit.  After 
the  wick  has  been  spread  in  the  form  of 
a  coronet  at  the  top  of  the  lamp,  a  pla- 
tina-wire  cage,  containing  one  piece  of 
spongy  platina,  is  to  be  pricked  into  the 
centre  of  the  wick,  and  to  be  kept  near- 
ly in  contact,  but  not  to  touch  it.  After 
the  reservoir  has  been  filled  with  alcohol, 
the  wick  is  to  be  inflamed,  and  a  minute 
afterwards  the  spongy  platina  becomes 
incandescent,  when  the  flame  of  the  wick 
is  to  be  suddenly  blown  out,  and  the 
glass  cover  to  be  immediately  placed  over 
the  platina.  Without  any  further  care 
or  attention,  the  platina  ball  will  keep  ig- 
nited for  thirteen  or  fourteen  days  and 
nights.  If  a  tube  is  connected  with  a  re- 
servoir (containing  a  sufficient  quantity 
of  alcohol)  and  the  bottom  of  the  reser- 
voir of  the  lamp,  the  platina  ball  may  be 
kept  ignited  for  years,  as  the  spongy  pla- 
tina does  not  appear  to  be  in  the  least 
deteriorated  by  being  kept  in  a  state  of 
constant  ignition.  Two  objections  to 
this  lamp,  the  expense  of  the  alcohol  and 
the  odor  are  removed,  since  equal  parts 
of  alcohol  and  whisky  answer  as  well 
as  pure  alcohol  ;  or  one-third  of  al- 
cohol and  two-thirds  of  whisky,  which 
cost  two  cents  for  eight  hours.  Whis- 
key consists  of  4  parts  of  alcohol  and 
3  parts  of  water.  As  a  remedy  for 
the  second  objection,  an  apparatus  for 
condensing  the  vapor  is  made  of  tin, 
which  is  to  be  suspended  from  a  nail  in 
the  wall.  The  glass  tube  of  the  lamp  is 
to  be  inserted  into  the  tin  tube  of  the 
condensing  apparatus,  which  will  com- 
pletely destroy  the  strong  odor  of  the 
vapor,  and  the  liquid  is  drawn  off  by  the 
stop-cock  at  the  side  of  the  condenser. 

Spirit-lamps  are  those  used  with  cot- 
ton wicks  and  alcohol,  and  though  the 
flame  is  slight  the  heat  is  intense,  and 
its  action  on  metals,  &c,  effective.  As 
the  alcohol  approximates  pure  hydrogen, 
and  has  little  carbon,  it  fixes  much  oxy- 
gen, which  confers  the  heat,  and  there 
being  no  carbon,  there  is  little  light  and 
no  smoke  ;  so  that  it  forms  no  carbonic 
acid,  and  the  gases  are  concentrated  into 
aqueous  vapor,  giving  out  great  heat  for 
alt  chemical  purposes.  The  heat  is  great- 
est just  within  the  summit.  Sometimes 
four  burners  are  used,  and  one  and  two 
chimneys  above  each  other,  to  place  over 
the  whole,  allowing  air  to  enter  at  the 


bottom,  and  in  this  case  the  highest  de- 
grees of  heat  are  attained  at  an  easy  ex- 
pense. The  spirits  or  alcohol  should 
have  0*85  spec,  grav.,  i.  e.,  six  pints 
should  weigh  five  pints  of  water. 

Spirit-lamps  produce  little  flame  but 
intense  heat,  since  white  light  and  flame 
result  from  the  joint  action  of  hydro- 
gen and  carbon.  They  are  to  be  trimmed 
with  a  twisted  cotton  wick  and  alcohol, 
and  they  have  the  advantage  of  intense 
heat,  without  smoke  or  chemical  combi- 
nation with  substances  applied  to  them. 

Sometimes  several  wicks  are  combined 
in  a  hollow  cylinder,  raised  above  the  ta- 
ble, and  a  chimney  may  be  added,  with 
which  it  becomes  a  powerful  furnace. 
The  alcohol  should  be  about  '84  or  -85. 
Pyroligneous  ether  may  be  substituted 
for  alcohol,  as  cheaper  in  some  countries. 

Double  wick,  and  Argand  oil-lamps 
with  separate  rack-work,  are  very  pow- 
erful and  luminous,  with  free  access  of  air. 

To  prevent  the  breaking  of  lamp-glasses 
by  sudden  heat,  cut  or  scratch  the  base 
of  the  glass  with  a  diamond,  and  after- 
wards sudden  heat  may  be  applied  with- 
out dansrer. 

LAMP  OF  DAVY  consists  of  a  com- 
mon oil  lamp,  surmounted  with  a  covered 
cylinder  of  wire  gauze,  for  transmitting 
light  to  the  miner  without  endangering 
the  kindling  of  the  atmosphere  of  fire- 
damp which  may  surround  him  ;  because 
carbureted  hydrogen,  in  passing  through 
the  meshes  of  the  cylindric  cover,  gets 
cooled  by  the  conducting  power  of  the 
metallic  gauze,  below  the  point  of  its 
ascension. 

The  frequency  of  explosions  in  coal 
mines  in  England  led  the  Mining  Board 
of  that  country  to  applv  to  Sir  H.  Davy 
in  the  hope  he  might  be  able  to  apply 
some  means  for  its  prevention.  The  ex- 
periments which  he  undertook  for  this 
end  were  numerous,  and  ended  in  the 
formation  of  this  lamp.  He  found  that 
the  fire  damp  of  the  coal  mine  (carburet- 
ted  hydrogen)  was  not  explosive  unless 
mixed  with,  air,  and  that  ten  times  its 
volume  of  air  was  the  most  explosive 
proportions ;  that  even  in  these  propor- 
tions it  did  not  explode  unless  a  body  in 
futt  ignition — that  is,  in  flame.,  were 
brought  in  contact  with  it.  He  also 
found  that  when  the  gas  was  inflamed 
and  made  to  pass  through  metal  tubes  of 
small  diameter,  it  cooled  so  much  as  not 
to  set  the  surrounding  gas  on  fire,  and 
that  it  kept  the  inflamed  and  uninflamed 
portions  perfectly  distinct.  On  further 
experiment,  he  found  that  sections  of 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


295 


tubes  answered  as  well  as  tubes  of  any 
length,  and  hence  a  sheet  of  wire-gauze 
was  equally  efficient :  he  formed  his  safe- 
ty lamp  therefore  of  a  tube  of  gauze,  which 
prevented  the  inner  flame  of  gas  from 
spreading  outwards  into  the  great  body 
of  fire  damp.  It  has  been  the  means  of 
saving  many  hundred  lives  ;  but  miners 
will  carelessly  open  it  to  have  more  light 
to  work  with,  or  to  light  their  pipes, 
when  if  the  fire-damp  be  in  the  passages 
an  explosion  must  occur.  Improvements 
have  been  made  in  Davy's  lamp  by  Drs. 
Keid  and  Clanny,  by  substituting  for  the 
lateral  wire  gauze  a  glass  shade  closed 
at  top  with  gauze. 

The  apertures  in  the  gauze  should  not 
be  more  than  l-20th  of  an  inch  square. 
Since  the  fire-damp  is  not  inflamed  by 
ignited  wire,  the  thickness  of  the  wire 
is  not  of  importance,  but  wire  from  l-40th 
to  l-60th  of  an  inch  in  diameter  is  the 
most  convenient. 

The  cage  or  cylinder  should  be  made 
by  double  joinings,  the  gauze  being  fold- 
ed over  in  such  a  manner  as  to  leave  no 
apertures.  When  it  is  cylindrical,  it 
should  not  be  more  than  two  inches  in 
diameter ;  because  in  larger  cylinders, 
the  combustion  of  the  fire-damp  renders 
the  top  inconveniently  hot ;  a  double  top 
is  always  a  proper  precaution,  fixed  half 
or  three  quarters  of  an  inch  above  the 
first  top. 

The  gauze  cylinder  should  be  fastened 
to  the  lamp  by  a  screw  of  four  or  five 
turns,  and  fitted  to  the  screw  by  a  tight 
ring.  All  joinings  in  the  lamp  should 
be  made  with  hard  solder,  as  the  secur- 
ity depends  upon  the  circumstance  that 
no  aperture  exists  in  the  apparatus  larger 
than  in  the  wire  gauze. 

LAMPBLACK.  Finely  divided  char- 
coal. It  is  the  soot  obtained  by  the  im- 
perfect combustion  of  resin  of  turpen- 
tine ;  this  is  burned  in  chambers  hung 
with  old  sacking,  upon  which  the  smoke 
collects,  and  is  from  time  to  time  sciaped 
off.  It  contains  about  20  per  cent,  of  pe- 
culiar resinous  products,  water,  and  saline 
matter. 

LAMPIC  ACID.  A  term  given  by 
■Mr.  Daniell  to  the  acid  produced  by  the 
slow  combustion  of  the  vapor  of  alcohol 
and  ether  in  the  lamp  without  flame  :  he 
has  since  ascertained  that  it  is  acetic  acid 
modified  by  the  presence  of  a  peculiar 
hydrocarbon. 

LAND  SPRINGS.  Land  springs  are 
sources  of  water  which  only  come  into 
action  after  heavy  rains  ;  while  constant 
springs,  which  derive  their  supplies  from 


a  more  abundant  source,  flow  through- 
out the  year.  All  springs  owe  their  ori- 
gin to  rains.  In  the  case  of  land  springs, 
the  water,  when  it  sinks  through  the 
surface,  is  speedily  interrupted  by  a  re- 
tentive stratum,  and  there  accumulating, 
soon  bursts  out  in  a  spring,  which  ceases 
to  flow  a  short  period  alter  the  cause 
which  gave  it  birth  has  ceased  to  ope- 
rate ;  but  the  water  which  supplies  con- 
stant springs  sinks  deeper  into  the  earth, 
and  accumulates  in  rocky  or  gravelly 
strata,  which  become  saturated  with  the 
fluid. 

LAPIDARY,  Akt  of.  The  art  of  the 
lapidary,  or  that  of  cutting,  polishing, 
and  engraving  gems,  was  known  to  the 
ancients,  many  of  whom  have  left  admir- 
able specimens  of  their  skill.  The  Greeks 
were  passionate  lovers  of  rings  and  en- 
graved stones ;  and  the  most  parsimo- 
nious among  the  higher  classes  of  the 
Cyrenians  are  said  to  have  worn  rinejs  of 
the  value  of  ten  minaa  (about  $150  ot  our 
money).  By  far  the  greatest  part  of  the 
antique  gems  that  have  reached  modern 
times,  may  be  considered  as  so  many 
models  for  forming  the  taste  of  the  stu- 
dent of  the  fine  arts,  and  for  inspiring 
his  mind  with  correct  ideas  of  what  is 
truly  beautiful.  With  the  cutting  of  the 
diamond,  however,  the  ancients  were 
unacquainted,  and  hence  they  wore  it  in 
its  natural  state.  Even  in  the  middle 
ages,  this  art  was  still  unknown  ;  for  the 
four  large  diamonds  which  enrich  the 
clasp  oi'the  imperial  mantle  of  Charle- 
magne, as  now  preserved  in  Paris,  are 
uncut,  octahedral  crystals.  But  the  art 
of  working  diamonds  was  probably  known 
in  Hindostan  and  China,  in  very  remote 
periods.  After  Louis  de  Berghen's  dis- 
covery, in  1476,  of  polishing  two  dia- 
monds by  their  mutual  attrition,  all  the 
finest  diamonds  were  sent  to  Holland  to 
be  cut  and  polished  by  the  Dutch  artists, 
who  long  retained  a  superiority,  now  no 
longer  admitted  by  the  lapidaries  of  Lon- 
don and  Paris. 

The  operation  of  gem-cutting  is  abridg- 
ed by  two  methods  :  1st,  by  cleavage  ; 
2d,  by  cutting  off  slices  with  a  fine  wire, 
coated  with  diamond  powder,  and  fixed 
in  the  stock  of  a  hand-saw.  Diamond  is 
the  only  precious  stone  which  is  cut  and 
polished  with  diamond  powder,  soaked 
with  olive  oil,  upon  a  mill  plate  of  very 
soft  steel. 

Oriental  rubies,  sapphires,  and  to- 
pazes, are  cut  with  diamond  powder 
soaked  with  olive  oil,  on  a  copper  wheel. 
The  facets  thus  formed  are  afterwards 


296 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


|  LAP 


polished  on  another  copper  wheel  with 
tripoli,  tempered  with  water. 

Emeralds,  hyacinths,  amethysts,  gar- 
nets, agates,  and  other  softer  stones,  are 
cut  at  a  lead  wheel,  with  emery  and 
water  ;  and  are  polished  on  a  tin  wheel 
with  tripoli  and  water,  or,  still  better, 
on  a  zinc  wheel,  with  putty  of  tin  and 
water. 

The  more  tender  precious  stones,  and 
even  the  pastes,  are  cut  on  a  mill-wheei 
of  hard  wood,  with  emery  and  water ; 
and  are  polished  with  tripoli  and  water 
on  another  wheel  of  hard  wood. 

Since  the  lapidary  employs  always  the 
same  tools,  whatever  be  the  stone  which 
he  cuts  or  polishes,  and  since  the  wheel 
discs  alone  vary,  as  also  the  substance  he 
uses  with  them,  we  shall  describe,  very 
briefly,  his  apparatus,  and  the  manipu- 
lations for  diamond-cutting,  which  are 
applicable  to  every  species  of  stone. 

Diamonds  are  cut  at  the  present  day 
in  only  two  modes ;  into  a  rose  dia- 
mond, and  a  brilliant.  We  shall  there- 
fore confine  our  attention  to  these  two 
forms. 

The  rose  diamond  is  flat  beneath,  like 
all  weak  stones,  while  the  upper  face 
rises  into  a  dome,  and  is  cut  into  facets. 
Most  usually  six  facets  are  put  on  the 
central  region,  which  are  in  the  form  of 
triangles,  "and  unite  at  their  summits  ; 
their  bases  abut  upon  another  range  of 
triangles,  which  being  set  in  an  inverse 
position  to  the  preceding,  present  their 
bases  to  them,  while  their  summits  ter- 
minate at  the  sharp  margin  of  the  stone. 
The  latter  triangles  leave  spaces  between 
them  which  are  likewise  cut  each  into 
two  facets.  By  this  distribution  the  rose 
diamond  is  cut  into  24  facets  ;  the  sur- 
face of  the  diamond  being  divided  into 
two  portions,  of  which  the  xipper  is 
called  the  crown,  and  that  forming  the 
contour,  beneath  the  former,  is  called 
dentelle  (lace)  by  the  French  artists. 
^  According  to* Mr.  Jeffries,  in  his  Trea- 
tise on  Diamonds,  the  regular  rose  dia- 
mond is  formed  by  inscribing  a  regular 
octagon  in  the  centre  of  the  table  side  of 
the  stone,  and  bordering  it  by  eight 
right-angled  triangles,  the  bases  of  which 
correspond  with  the  sides  of  the  octagon  ; 
beyond  these  is  a  chain  of  eight  trape- 
ziums, and  another  of  sixteen  triangles. 
The  collet  side  also  consists  of  a  minute 
central  octagon,  from  every  angle  of 
which  proceeds  a  ray  to  the  edge  of  the 
girdle,  forming  the  whole  surface  into 
eight  trapeziums,  each  of  which  is  again 
subdivided  by  a  salient  angle  (whose  apex 


touches  the  girdle)  into  one   irregular 
pentagon  and  two  triangles. 

To  fashion  a  rough  diamond  into  a 
brilliant,  the  first  step  is  to  modify  the 
faces  of  the  original  octahedron,  so  that 
the  plane  formed  by  the  junction  of  the 
two  pyramids  shall  be  au  exact  square, 
and  the  axis  of  the  crystal  precisely  twice 
the  length  of  one  of  the  sides  of  the 
square.  The  octahedron  being  thus  rec- 
tified, a  section  is  to  be  made  parallel  to 
the  common  base  or  girdle,  so  as  to  cut 
off  5-18ths  of  the  whole  height  from  the 
upper  pyramid,  and  1-1 8th  from  the 
lower  one.  The  si  perior  and  larger 
plane  thus  produced  is  called  the  tuble, 
and  the  inferior  and  smaller  one  is  called 
the  collet;  in  this  state  it  is  termed  a 
complete  square  table  diamond.  To  con- 
vert it  into  a  brilliant,  two  triangular  fa- 
cets are  placed  on  each  side  of  the  table, 
thus  changing  it  from  a  square  to  an  oc- 
tagon ;  a  lozenge-shaped  facet  is  also 
placed  at  each  of  the  tour  corners  of  the 
table,  and  another  lozenge  extending 
lengthwise  along  the  whole  of  each  side 
of  the  original  square  of  the  table,  which 
with  two  triangular  facets  set  on  the 
base  of  each  lozenge,  completes  the 
whole  number  of  facets  on  the  table  side 
of  the  diamond,  viz.,  8  lozenges  and  24 
triangles.  On  the  collet  side  are  formed 
4  irregular  pentagons,  alternating  with 
as  many  irregular  lozenges  radiating 
from  the  collet  as  a  centre,  and  bordered 
by  16  triangular  facets  adjoining  the 
girdle.  The  brilliant  being  thus  com- 
pleted, is  set  with  the  table  side  upper- 
most, and  the  collet  side  implanted  in 
the  cavity  made  to  receive  the  diamond. 
The  brilliant  is  always  three  times  as 
thick  as  the  rose  diamond.  In  France, 
the  thickness  of  the  brilliant  is  set  off 
into  two  unequal  portions ;  one-third  is 
reserved  for  the  upper  part  or  table  of 
the  diamond,  and  the  remaining  two- 
thirds  for  the  lower  part  or  collet  (cu- 
l-asse).  The  table  has  eight  planes,  and 
its  circumference  is  cut  into  facets,  of 
which  some  are  triangles,  and  others  lo- 
zenges. The  collet  is  also  cut  into  facets 
called  pavilion*.  It  is  of  consequence 
that  the  pavilions  lie  in  the  same  order* 
as  the' upper  facets,  and  that  they  corre- 
spond to  each  other,  so  that  the  symme- 
try be  perfect,  for  otherwise  the  play  of 
the  light  would  be  false. 

Although  the  rose  diamond  projects 
bright  beams  of  light  in  more  extensive 
proportion  often  than  the  brilliant,  yet 
the  latter  shows  an  incomparably  greater 
play,  from  the  difference  of  its  cutting. 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


297 


In  executing  this,  there  are  formed  32 
faces  of  different  figures,  and  inclined  at 
different  angles  all  round  the  table,  on 
the  upper  side  of  the  stone.  On  the  col- 
let (culasse)  24  other  faces  are  made 
round  a  small  table,  which  converts  the 
culasse  into  a  truncated  pyramid.  These 
24  facets,  like  the  32  above,  are  differ- 
ently inclined  and  present  different  fi- 
gures. It  is  essential  that  the  faces  of 
the  top  and  the  bottom  correspond  to- 
gether in  sufficiently  exact  proportions  to 
multiply  the  reflections  and  refractions, 
so  as  to  produce  the  colors  of  the  pris- 
matic spectrum. 

The  other  precious  stones,  as  well  as 
their  artificial  imitations,  called  pastes, 
are  cut  in  the  same  fashion  as  the  bril- 
liant ;  the  only  difference  consists  in  the 
matter  constituting  the  wheel  plates,  and 
the  grinding  and  polishing  powders,  as 
already  stated. 

In  cutting  the  stones,  they  are  mount- 
ed on  the  cement-rod,  whose  stem  is  set 
upright  in  a  socket  placed  in  the  middle 
of  a  sole  piece,  which  receives  the  stem 
of  the  cement-rod.  The  head  of  the  rod 
fills  the  cup  of  the  sole  piece.  A  melted 
alloy  of  tin  and  lead  is  poured  into  the 
head  of  the  cement-rod,  into  the  middle 
of  which  the  stone  is  immediately  plung- 
ed ;  and  whenever  the  solder  has  be- 
come solid,  a  portion  of  it  is  pared  off 
from  the  top  of  the  diamond,  to  give  it  a 
pyramidal  form. 

There  is  an  instrument  employed  by 
the  steel  polishers  for  pieces  of  clock- 
work, and  by  the  manufacturers  of 
watch-glasses  for  polishing  their  edges. 
It  consists  of  a  solid  oaken  table,  the  top 
of  which  is  perforated  with  two  holes, 
one  for  passing  through  the  pulley  and 
the  arbor  of  a  wheel-plate,  made  either 
of  lead  or  of  hard  wood,  according  to 
circumstances ;  and  the  other  for  receiv- 
ing the  upper  part  of  the  arbor  of  the 
large  pulley.  The  upper  pulley  of  the 
wheel-plate  is  supported  by  an  iron 
prop,  fixed  to  the  table  by  two  wooden 
screws.  The  inferior  pivots  of  the  two 
pieces  are  supported  by  screw -sockets, 
working  in  an  iron  screw-nut  sunk  into 
a  summer-bar.  The  legs  of  the  table 
are  made  longer  or  shorter,  according  as 
the  workman  chooses  to  stand  or  sit  at 
his  employment.  Emery  with  oil  is 
used  for  grinding  down,  and  tin-putty  or 
colcothar  for  polishing.  The  workman 
lays  the  piece  on  the  flat  of  the  wheel- 
plate  with  one  hand,  and  presses  it  down 
with  a  lump  of  cork,  while  lie  turns 
round  the  handle  with  the  other  hand. 
13* 


The  Sapphire j  Ruby,  Oriental  Ame- 
thyst, Oriental  Emerald,  and  Oriental  To- 
paz, are  gems  next  in  value  and  hardness 
to  diamond ;  and  they  all  consist  of 
nearly  pure  alumina  or  clay,  with  a  mi- 
nute portion  of  iron  as  the  coloring  mat- 
ter. The  following  analyses  show  the 
affinity  in  composition  of  the  most  pre- 
cious bodies  with  others  in  little  relative 
estimation. 


Sapphire. 

Corundum 
Stone. 

Emery. 

Alumina  or  clay  . . . 

98-5 
00 
10 
0-5 

8950 
5-50 
1-25 
0  00 

860 
30 

Oxide  of  iron 

4  0 

0-0 

1000 

96  25 

930 

Salamstone  is  a  variety  which  consists 
of  small  transparent  crystals,  generally 
six-sided  prisms,  of  pale  reddish  and 
bluish  colors.  The  corundum  of  Batta- 
gammana  is  frequently  found  in  large 
six-sided  prisms  :  it  is  commonly  of  a 
brown  color,  whence  it  is  called  by  the 
natives  curundu  galle,  cinnamon  stone. 
The  hair-brown  and  reddish-brown  crys- 
tals are  called  adamantine  spar.  Sap- 
phire and  salamstone  are  chiefly  met 
with  in  secondary  repositories,  as  'in  the 
sand  of  rivers,  &c,  accompanied  by  crys- 
tals and  grains  of  octahedral  iron-ore 
and  of  several  species  of  gems.  Corun- 
dum is  found  in  imbedded  crystals  in  a 
rock,  consisting  of  idianite.  Adaman- 
tine spar  occurs  in  a  sort  of  granite. 

The  finest  varieties  of  sapphire  come 
from  Pegu,  where  they  occur  in  the  Ca- 

Eelan  mountains  near  Syria.  Some  have 
een  found  also  at  Hohenstein  in  Saxony, 
Bilin  in  Bohemia,  Puy  in  France,  and  in 
several  other  countries.  The  red  va- 
riety, the  ruby,  is  most  highly  valued. 
Its  color  is  between  a  bright  scarlet  and 
crimson.  A  perfect  ruby  above  3i  ca- 
rats is  more  valuable  than  a  diamond  of 
the  same  weight.  If  it  weigh  1  carat,  it 
is  worth  $52 ;  2  carats,  $208 ;  3  carats, 
$780  ;  6  carats,  $52000.  A  deep  colored 
ruby,  exceeding  20  carats  in  weight,  is 
generally  called  a  carbuncle ;  of  which 
108  were  said  to  be  in  the  throne  of  the 
Great  Mogul,  weighing  from  100  to  200 
carats  each  :  but  this  statement  is  proba- 
bly incorrect.  The  largest  oriental  ruby 
known  to  be  in  the  world  was  brought 
from  China  to  Prince  Gargarin,  governor 
of  Siberia.  It  came  afterwards  into  the 
possession  of  Prince  Menzikoff,  and  con- 


298 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


stitutes  now  a  jewel  in  the  imperial  crown 
of  Russia. 

A  good  blue  sapphire  of  10  carats  is 
valued  at  $260.  It  it  weighs  20  carats, 
its  value  is  $1040 ;  but  under  10  carats, 
the  price  may  be  estimated  by  multiply- 
ing the  square  of  its  weight  in  carats  into 
a  quarter  eagle  ;  thus,  one  of  four  carats 
would  be  worth  4*  X  i  E.  =  $40.  It  has 
been  said  that  the  blue  sapphire  is  su- 
perior in  hardness  to  the  red,  but  this  is 
probably  a  mistake  arising  from  con- 
founding the  corundum  ruby  with  the 
spinelle  ruby.  A  sapphire  of  a  barbel 
blue  color,  weighing  6  carats,  was  dis- 
posed of  in  Paris  by  public  sale  for  $350 ; 
and  another  of  an  indigo  blue,  weighing  j 
6  carats  and  3  grains,  brought  $300 : 
both  of  which  sums  much  exceed  what 
the  preceding  rule  assigns,  from  which 
we  may  perceive  how  far  fancy  may  go 
in  such  matters.  The  sapphire  of  Brazil 
is  merely  a  blue  tourmaline,  as  its  spe- 
cific gravity  and  inferior  hardness  show. 
White  sapphires  are  sometimes  so  pure 
that  when  properly  cut  and  polished  they 
have  been  passed  for  diamonds. 

The  yellow  and  green  sapphires  are 
much  prized  under  the  names  of  Orien- 
tal topaz  and  emerald.  The  specimens 
which  exhibit  all  these  colors  associated 
in  one  stone  are  highly  valued,  as  they 
prove  the  mineralogical  identity  of  these 
varieties. 

Besides  these  shades   of  color,   sap- 

f>hires  often  emit  a  beautiful  play  of  co- 
ors,  or  chatoiement,  when  held  in  differ- 
ent positions  relative  to  the  eye  or  inci- 
dent light ;  and  some  likewise  present 
star-like  radiations,  whence  they  are 
called  star-stones  or  asterias ;  sending 
forth  6  or  even  12  rays,  that  change  their 

?lace  with  the  position  of  the  stone. 
'his  property,  so  remarkable  in  certain 
blue  sapphires,  is  not,  however,  peculiar 
to  these  gems.  It  seems  to  belong  to 
transparent  minerals  which  have  a  rhom- 
boid for  their  nucleus,  and  arises  from 
the  combination  of  certain  circumstances 
in  their  cutting  and  structure.  Lapida- 
ries often  expose  the  light-blue  variety 
of  sapphire  to  the  action  of  fire,  in  order 
to  render  it  white  and  more  brilliant; 
but  with  regard  to  those  found  at  Ex- 
pailly,  in  France,  fire  deepens  their  color. 
8.  Ckrysoberyl,  called  by  Haiiy,  Cymo- 
phane,  and  by  others,  Prismatic  corun- 
dum, ranks  next  in  hardness  to  sapphire, 
being  8*5  on  the  same  scale  of  estimation. 
Its  specific  gravity  is  3*754.  It  usually 
occurs  in  rounded  pieces  about  the  size 
of  a  pea,  but  it  is  also  found  crystallized 


in  many  forms,  of  which  8-sided  prisms 
with  8-sided  summits  are  perhaps  the 
most  frequent.  Lustre  vitreous,  color 
asparagus  green,  passing  into  greenish- 
white  and  olive-green.  It  shows  a  bluish 
opalescence,  alight  undulating,  as  it  were, 
in  the  stone,  when  viewed  in  certain  di- 
rections ;  which  property  constitues  its 
chief  attraction  to  the  jeweller.  When 
polished,  it  has  been  sometimes  mistaken 
for  a  yellow  diamond ;  and  from  its  hard- 
ness and  lustre  is  considerably  valued. 
Good  specimens  of  it  are  very  rare.  It 
has  been  found  only  in  the  alluvial  de- 
posites  of  rivers,  along  with  other  species 
of  gems.  Thus  it  occurs  in  Brazil,  along 
with  diamonds  and  prismatic  topaz ;  also 
in  Ceylon.  Its  constituents  are  alumina, 
68-66;  glucina,  16*00;  silica,  6*00;  pro- 
toxide of  iron,  4*7 ;  oxyde  of  titanium, 
2*66;  moisture,  0*66;  according  to  Sey- 
bert's  analysis  of  a  specimen  from  Brazil. 
It  is  difficultly  but  perfectly  fusible  before 
the  blow-pipe,  with  borax  and  salt  of 
phosphorus.  In  composition  it  differs 
entirely  from  sapphire,  or  the  rhombohe- 
dral  corundum. 

4.  Spinelle  Ruby,  called  Dodecahedral 
corundum,  by  some  mineralogists,  and 
Balas  ruby,  by  lapidaries.  Its  hardness 
is  8.  Specific  gravity,  3*523.  Its  funda- 
mental form  is  the  hexahedron,  but  it  oc- 
curs crystallized  in  many  secondary  forms : 
octahedrons,  tetrahedrons,  and  fhombo- 
hedrons.  Fracture,  conchoidal ;  lustre, 
vitreous ;  color,  red,  passing  into  blue 
and  green,  yellow,  brown,  and  black ;  and 
sometimes  it  is  nearly  white.  Bed  spi- 
nelle consists  of  alumina,  74*5;  silica,  15*5 ; 
magnesia,  8*25;  oxide  of  iron,  1*5;  lime, 
0*75.  Vauquelin  discovered  6*18  per  cent. 
of  chromic  acid  in  the  red  spinelle.  The 
red  varieties  exposed  to  neat  become 
black  and  opaque  ;  on  cooling,  they  ap- 
pear first  green,  then  almost  colorless,  but 
at  last  resume  their  red  color.  Pleonaste 
is  a  variety  which  yields  a  deep  green 
globule  with  borax. 

Crystals  of  spinelle  from  Ceylon  have 
been  observed  imbedded  in  limestone, 
mixed  with  mica,  or  in  rocks  containing 
adularia,  which  seem  to  have  belonged  to 
a  primitive  district.  Other  varities  like 
the  pleonaste  occur  in  the  drusy  cavities 
of  rocks  ejected  by  Vesuvius.  Crystals  of 
it  are  often  found  in  diluvial  and  alluvial 
sand  and  gravel,  along  with  true  sap- 
phires, pyramidal  zircon,  and  other  gems; 
as  also  with  octahedral  iron  ore,  in  Cey- 
lon. Blue  and  pearl-gray  varieties  occur 
in  Siidermannland,  in  Sweden,  imbedded 
in  granular  limestone.    Pleonaste  is  met 


lap] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


299 


with  also  in  the  diluvial  sands  of  Ceylon. 
Clear  and  finely  colored  specimens  of'spi- 
nelle  are  highly  prized  as  ornamental 
stones.  When  the  weight  of  a  good  spi- 
nelle  exceeds  4  carats,  it  is  said  to  be  val- 
ued at  half  the  price  of  a  diamond  of  the 
same  weight.  M.  Brard  has  seen  one  at 
Paris  which  weighed  215  grains. 

5.  Zircon  or  Hyacinth.  Its  fundamental 
form  is  an  isosceles  4-sided  pyramid ; 
and  the  secondary  forms  have  all  a  pyra- 
midal character.  Fracture,  conchoidal, 
uneven ;  lustre,  more  or  less  perfectly 
adamantine ;  colors,  red,  brown,  yellow, 
gray,  green,  white;  which,  with  the  ex- 
ception of  some  red  tints,  are  not  briffht. 
Hardness,  7-5.  Specific  gravity,  4-5.  Zir- 
con and  hyacinth  consist,  according  to 
Klaproth,  of  almost  exactly  the  same  con- 
stituents ;  namely,  zirconia,  70 ,  silica, 
25  ;  oxyde  of  iron,  5.  In  the  white  zir- 
conia there  is  less  iron  and  more  silica. 
Before  the  blowpipe  the  hyacinth  loses 
its  color,  but  does  not  melt.  The  brighter 
zircons  are  often  worked  up  into  alrilliant 
form,  for  ornamenting  watch  cases.  As 
a  gem,  hyacinth  has  no  high  value.  It  has 
been  often  confounded  with  other  stones, 
but  its  very  great  specific  gravity  makes  it 
to  be  readily  recognized. 

6.  Topaz.  The  fundamental  form  is  a 
scalene  4-sided  pyramid ;  but  the  second- 
ary forms  have  a  prismatic  character ;  and 
are  frequently  observed  in  oblique  4-sided 

}>risms,  acuminated  by  4  planes.  The 
ateral  planes  of  the  prism  are  longitudin- 
ally striated.  Fracture,  conchoidal,  un- 
even ;  lustre,  vitreous  ;  colors,  white,  yel- 
low, green,  blue;  generally  of  pale  shades. 
Hardness,  8  ;  specific  gravity,  3-5.  Pris- 
matic topaz  consists,  according  to  Berze- 
lius,  of  alumina,  57*45;  silica,  34-24;  flu- 
oric acid,  7*75.  In  a  strong  heat  the  faces 
of  crystallization,  but  not  those  of  cleav- 
age, are  covered  with  small  blisters,  which 
however  immediately  crack.  With  borax, 
it  melts  slowly  into  a  transparent  glass. 
Its  powder  colors  the  tincture  of  violets 
green.  Those  crystals  which  possess  dif- 
ferent faces  of  crystallization  on  opposite 
ends,  acquire  the  opposite  electricities  on 
being  heated.  By  friction,  it  acquires  po- 
sitive electricity. 

Most  perfect'crystals  of  topaz  have  been 
found  in  Siberia,  of  green,  blue,  and  white 
colors,  along  with  beryl,  in  the  Uralian 
and  Altai  mountains,  as  also  in  Kams- 
chatka ;  in  Brazil,  where  they  generally 
occur  in  loose  crystals,  and  pebble  form's 
of  bright  yellow 'colors;  and  in  Mucla,  in 
Asia  Minor,  in  pale  straw-yellow  regular 
crystals.     They  are  also  met  with  in  the 


granitic  detritus  of  Cairngorm,  in  Aber- 
deenshire. The  blue  varieties  are  absurd 
ly  called  oriental  aquamarine,  by  lapida- 
ries. If  exposed  to  heat,  the  Saxon  topaz 
loses  its  color  and  becomes  white ;  the 
deep  yellow  Brazilian  varieties  assume  a 
pale  pink  hue;  and  are  then  sometimes 
mistaken  for  spinelle,  to  which,  however, 
they  are  somewhat  inferior  in  hardness. 
Topaz  is  also  distinguishable  by  its  double 
retractive  property"  Tavernier  mentions 
a  topaz,  in  the  possession  of  the  Great 
Mogul,  which  weighed  157  carats,  and 
cost  £27,000  sterling.  There  is  a  speci- 
men in  the  museum  of  natural  history  at 
Paris  which  weighs  4  ounces  2  grs. 

Topazes  are  not  scarce  enough  to  be 
much  valued  by  the  lapidary. 

7.  Emerald  and  Beryl  are  describee  in 
their  alphabetical  places.  Emerald  la  es 
its  lustre  by  candle-light ;  but  as  it  ap- 
pears to  most  advantage  when  in  the  com- 
pany of  diamonds,  it  is  frequently  sur- 
rounded with  brilliants,  and  occasionally 
with  pearls.  Beryl  is  the  aquamarine  of 
the  jewellers,  and  has  very  little  estima- 
tion among  lapidaries. 

8;  Garnet.  See  this  stone  in  its  alpha- 
betical place. 

9.  Chrysolite,  called  Peridot,  by  Hauy  ; 
probably  the  topaz  of  the  ancients,  as  our 
topaz  was  their  chrysolite.  It  is  the  soft- 
est of  the  precious  stones,  being  scratched 
by  quartz  and  the  file.     It  refracts  double. 

10.  Qvartz,  including,  as  sub-species, 
Amethyst,  Bock  -  crystal,  Bose  -  quartz, 
Prase,  or  Chrysoprase,  and  several  vari- 
eties of  calcedony,  as  Oafs-eye,  Plasma, 
Chrysoprase,  Onyx,  Sardonyx,  &c.  Lus- 
tre, vitreous,  inclining  sometimes  to  re- 
sinous j  colors,  very  various ;  fracture, 
conchoidal;  hardness,  7;  specific  gravity, 
2-69. 

11.  Opal,  or  uncleavable  quartz.  Frac- 
ture, conchoidal ;  lustre,  vitreous  or  re- 
sinous; colors,  white,  yellow,  red,  brown, 
green,  gray.  Lively  play  of  light;  hard- 
ness, 5-5  to  6-5 ;  specific  gravity,  2-091. 
It  occurs  in  small  kidney-shaped  and  stal- 
actitic  shapes,  and  large  tuberose  concre- 
tions. The  phenomena  of  the  play  of  co- 
lors in  precious  opal  has  not  been  satisfac- 
torily explained.  It  seems  to  be  connect- 
ed with  the  regular  structure  of  the  min- 
eral. Hydrophane,  or  oculis  mundi,  is  a 
variety  of  opal  without  transparency,  but 
acquiring  it  when  immersed  in  water,  or 
in  any  transparent  fluid.  Precious  opal 
was  found  by  Klaproth  to  consist  of  silica, 
90;  water,  10;  which  is  a  very  curious 
combination.  Hungary  has  been  long  the 
only  locality  of  precious  opal,  where  it  oc- 


300 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lar 


curs  near  Caschau,  along  with  common 
and  semi-opal,  in  a  kind  of  porphyry. 
Fine  varieties  have,  however,  been  lately 
discovered  in  the  Faroe  islands  ;  and  most 
beautiful  ones,  sometimes  quite  transpa- 
rent, near  Gracias  a  Dios,  in  the  province 
of  Honduras,  America.  The  red  and  yel- 
low bright  colored  varieties  of  fire-opal 
are  found  near  Zimapan,  in  Mexico.  Pre- 
cious opal,  when  fashioned  for  a  gem,  is 
generally  cut  with  a  convex  surface ;  and 
if  large,  pure,  and  exhibiting  a  bright  play 
of  colors,  is  of  considerable  value.  In 
modern  times,  fine  opals  of  moderate  bulk 
have  been  frequently  sold  at  the  price  of 
diamonds  of  equal  size  :  the  Turks  being 
particularly  fond  of  them.  The  estima- 
tion in  which  opal  was  held  by  the  an- 
cients is  hardly  credible.  They  called  it 
Paideros,  or  Child  beautiful  as  love.  No- 
nius, the  Roman  senator,  preferred  ban- 
ishment to  parting  with  his  favorite  opal, 
which  was  coveted  by  Mark  Antonv. 
Opal  which  appears  quite  red  when  held 
against  the  light,  is  called  girasol  by  the 
French  ;  a  name  also  given  to  the  sapphire 
or  corundum  asterias  or  star-stone. 

12.  Turquois  or  Calaite.  Mineral  tur- 
quois  occurs  massive ;  fine-grained,  im- 
palpable ;  fracture,  conchoidal ;  color,  be- 
tween a  blue  and  a  green,  soft,  and  rather 
bright ;  opaqe ;  hardness,  6 ;  spec,  grav., 
2-83  to  3-0.  Its  constituents  are  alumina, 
73 ;  oxyde  of  copper,  4-5 ;  oxyde  of  iron, 
4 ;  water,  18 ;  according  to  Dr.  John. 
But  by  Berzelius,  it  consists  of  phosphate 
of  alumina  and  lime,  silica,  oxydes  or  cop- 
per, and  iron,  with  a  little  water.  It  has 
been  found  only  in  the  neighborhood  of 
Nichabour  in  the  Khorassan,  in  Persia; 
and  is  very  highly  prized  as  an  ornamental 
stone  in  that  country.  There  is  a  totally 
different  kind  of  turquois,  called  bane  tur- 
quois, which  seems  to  be  phosphate  of 
lime  colored  with  oxyde  of  copper.  When 
the  oriental  stone  is  cut  and  polished,  it 
forms  a  pleasing  gem  of  inferior  value. 
Malachite,  or  mountain  green,  a  compact 
carbonate  of  copper,  has  been  substituted 
sometimes  for  turquois,  but  their  shades 
are  different.  Malachite  yields  a  green 
streak,  and  turquois  a  white  one. 

13.  Lapis  lazuli  is  of  little  value,  on  ac- 
count ot  its  softness.  (See  Ultra  Ma- 
bine.) 

LARD.  The  fat  of  swine,  which  dif- 
fers in  situation  from  that  of  nil  other 
animals,  as  it  covers  the  hog  all  over, 
forming  a  distinct  and  continuous  layer 
between  the  flesh  and  skin,  like  the  blub- 
ber in  whales.  The  usual  mode  of  pre- 
paration is  to  melt  it  in  a  jar,  placed  in  a 


kettle  of  water,  and  then  to  level  it,  and 
run  it  into  bladders  that  have  been  clean- 
ed with  great  care.  The  smaller  the 
bladders  are,  the  better  the  lard  will  keep. 
The  fat  which  adheres  to  the  intestines 
differs  from  common  lard,  and  is  used  for 
lubricating  wheels  of  carriages.  The 
great  mass  of  lard  business  is  done  in 
Ohio,  having  Cincinnati  for  the  centre ; 
and  most  of  the  lard  oil  is  expressed  there. 
In  Cincinnati  it  is  calculated  that 
about  11,000,000  lbs.  of  lard  was  run 
into  lard  oil  this  last  year,  two-sevenths 
of  which  aggregate  will  make  stearine, 
the  residue  oil,  say  about  20,000  barrels 
of  42  gallons  each.  Much  the  larger 
share  of  this  is  of  inferior  lard,  made  of 
mast-fed  and  still-fed  hogs,  the  material, 
to  a  great  extent,  coming  from  a  distance 
— hence  the  poor  quality  of  western  lard 
oil.  Lard  oil,  besides  being  sold  for  what 
it  actually  is,  is  also  used  for  adulterating 
sperm  oil,  and  in  France  serves  to  mate- 
rially reduce  the  cost  of  olive  oil — the 
skill  of  the  French  chemists  enabling 
them  to  incorporate  from  60  to  70  per 
cent,  of  lard  oil  with  that  of  the  olive. 
There  is  also  an  establishment  in  that 
city,  which  besides  putting  up  hams,  &c, 
is  extensively  engaged  in  extracting  the 
grease  from  the  rest  of  the  hog.  It  has 
seven  large  circular  tanks,  six  of  capacity 
to  hold  each  15,000  lbs.,  and  one  6,000 
lbs.  These  receive  the  entire  carcass 
with  the  exception  of  the  hams,  and  the 
mass  is  subjected  to  the  steam  process, 
under  a  pressure  of  70  lbs.  to  the  square 
inch,  the  effect  of  which  operation  is  to 
reduce  the  whole  to  one  consistence,  and 
every  bone  to  powder.  The  fat  is  drawn 
off  by  cocks,  and  the  residuum,  a  mere 
earthy  substance,  is  taken  away  for 
manure.  Besides  the  hogs  which  reach 
this  factory  in  entire  carcasses,  the  great 
mass  of  heads,  ribs,  back  bones,  tail- 
pieces, feet,  and  other  trimmings  of  the 
hoes  cut  up  at  different  pork-houses,  are 
subjected  to  the  same  process,  in  order  to 
extract  every  particle  of  grease.  This 
concern  only  is  expected  to  turn  out  this 
season,  3,000,000  lbs.  of  lard,  five-sixths 
of  which  is  No.  1.  Six  hundred  hogs 
daily  pass  through  these  tanks,  one  day 
with  another. 

The  stearine  expressed  from  the  lard 
is  used  to  make  candles  for  being  sub- 
jected to  hydraulic  pressure,  by  which 
three-eighths  of  it  are  discharged  as  an 
impure  oleine ;  this  last  is  employed  in 
the  manufacture  of  soap.  3,000,000  lbs. 
of  stearine  have  been  made  in  one  year 
into  candles  and  soap  in  these  factories, 


lea] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


30  J 


and  they  can  make  6,000  lbs.  of  candles 
per  average  day  throughout  the  year. 

LARD  OIL.  This  year  (1851)  there 
are  40  manufacturies  of  lard  oil  in  Cin- 
cinnati, large  and  small,  which  consume 
on  an  average  the  year  round  1000  pack- 
ages, of  300  lbs.  each,  per  week,  which  is 
equal  to  52,000  packages,  or  15,600,000 
lbs.  per  annum — from  this  there  is  to  be 
deducted  one  third  for  stearine,  equal  to 
5,120,000  lbs.,  leaving  for  the  oil  10,480,000 
lbs.,  which  is  equal  to  1,310,000  gallons, 
allowing  8  lbs.  to  the  gallon.  Only  a  few 
years  back  the  manufacture  of  lard  oil 
was  looked  on  as  nothing,  now  it  occu- 
pies a  very  prominent  position,  and  has 
annually  a  "great  influence  upon  the  value 
of  the  hog.  Lard  oil  may  now  be  said  to 
have  taken  the  place  of  all  other  oils  for 
all  purposes  at  the  West.  Its  manufac- 
ture has  improved,  and  will  continue 
until  it  is  quite  equal  to  anyother  oil. 
As  an  application  to  machinery  it  is  found 
quite  equal  to  any  other  oil,  on  which 
account,  added  to  its  value  for  lighting 
purposes,  its  consumption  is  increasing 
in  the  Southern  and  Western  States. 
Every  town,  of  any  size,  when  lard  can 
be  had,  has  its  factory,  as  a  ready  sale  is 
always  found  for  the  stearine.  Lard,  when 
pressed,  yields  more  oil  and  less  stearine 
in  summer,  and  less  oil  and  more  stearine 
in  winter.  The  oil  is  dearer  in  winter. 
The  manufacture  of  lard  oil  is  carried  on 
mostly  in  Cincinnati,  the  country  in  every 
side  drawing  on  it  as  a  centre.  Its  manu- 
facture is  as  profitable  as  any  other  busi- 
ness of  the  same  capital,  its  basis  being 
cash.  Many  of  the  factories  have  now 
temporarily  ceased  working  owing  to  the 
present  high  price  of  lard,  and  lard-oil  in 
consequence,  has  risen  from  50  cents  up 
to  90  cents  per  gallon.     (See  Oils.) 

LATH-MAKING  MACHINE.  Mr. 
William  Merrill,  of  Northampton,  Por- 
tage Co.,  Ohio,  has  made  some  excellent 
improvements  on  machinery  for  making 
laths,  for  which  he  has  taken  measures 
to  secure  a  patent.  The  machine  makes 
the  laths  out  of  the  slabs  of  logs.  It  has  a 
circular  saw  which  slits  the  lath  out  of  a 
slab  as  it  is  fed  in,  and  it  has  a  revolving 
knife  on  the  saw  spindle,  which  turns 
the  edge  of  the  lath  after  the  saw  has  cut 
it.  The  slab  is  carried  forward  the  whole 
length,  allowing  the  saw  to  cut  a  lath  the 
whole  length,  when  a  projection  on  the 
saw  frame"  takes  the  slab,"  turns  it  over 
on  revolving  rollers,  which  bring  it  back 
to  the  person  to  feed  it  in,  who  stands  at 
the  end  of  the  frame,  and  merely  feeds 
in  the  slabs  to  the  slitting  saw. 


This  machine  has  a  register  to  it,  which 
rings  a  bell  when  a  hundred  laths  are 
finished,  to  tell  the  operator  that  a  bunch 
is  ready  for  binding,  so  that  no  counting 
is  required  for  that  purpose. 

LAYERS.  In  gardening,  a  mode  of 
propagating  plants  by  laying  down 
shoots,  and  covering  a  portion  of  them 
with  soil,  so  that  the  extremity  of  the 
shoot  is  left  above  ground,  and  the  shoot 
itself  not  detached  from  the  plant.  In 
order  to  facilitate  the  rooting  of  such 
layers,  the  portion  of  the  shoot  buried  in 
the  soil  is  fractured  by  twisting  or  bruis- 
ing, or  cut  with  a  knife  immediately 
under  a  bud.  This  operation,  by  ob- 
structing the  return  of  the  sap  from  the 
leaves,  occasions  its  accumulation  at  tb* 
wounded  part,  when  roots  are  there  pro- 
duced from  the  effort  of  nature  to  perpet- 
uate life. 

LAYING.  In  architecture,  the  first 
coat  on  lath  of  plasterer's  two-coat  work, 
the  surface  whereof  is  roughed  by  sweep- 
ing it  with  a  broom ;  the  difference  be- 
tween laying  and  rendering  being  that 
the  latter  is  the  first  coat  upon  brick. 

LEAD.  This  is  one  of  the  metals  most 
anciently  known,  being  mentioned  in  the 
books  of  Moses.  It  has  a  gray-blue  color, 
with  a  bright  metallic  lustre  when  newly 
cut,  but  it  becomes  soon  tarnished  and 
earthy-looking  in  the  air.  Its  texture  is 
close,  without  perceptible  cleavage  or  ap- 
pearance of  structure  ;  the  specific  gravity 
of  common  lead  is  11*352  ;  but  of  the  pure 
metal,  from  11-38  to  11*44.  It  is  very- 
malleable  and  ductile,  but  soft  and  desti- 
tute of  elasticity  ;  fusible  at  612°  Fahr., 
by  Crighton,  at  634°  by  Kupfer,  and  crys- 
tallizable  on  cooling,  into  octahedrons  im- 
planted into  each  other  so  as  to  form  ar 
assemblage  of  four-sided  pyramids. 

There  are  four  oxides  of  lead.  1 
The  suboxide,  of  a  grayish-blue  coloi, 
which  forms. a  kind  of  crust  upon  a  plate 
of  lead  long  exposed  to  the  air.  It  is 
procured  in  a  perfect  state  by  calcining 
oxalate  of  lead  in  a  retort;  the  dark  gray 
powder  which  remains,  is  the  pure  sub- 
oxide. 2.  The  protoxide  is  obtained  by 
exposiug  melted  lead  to  the  atmosphere, 
or,  more  readily,  by  expelling  the  acid 
from  the  nitrate  of  lead  by  heat  in  a  plati- 
num crucible.  It  is  yellow,  and  was  at 
one  time  prepared  as'  a  pigment  by  cal- 
cining lead,  but  is  now  superseded  by  the 
chromate  of  this  metal.  Litharge  is  mere- 
ly this  oxide  in  the  form  of  small  spangles, 
from  having  undergone  fusion  ;  it  is  more 
or  less  contaminated  with  iron,  copper, 
and  sometimes  a  little  silver.   It  contains 


302 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


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likewise  some  carbonic  acid.  The  above 
oxide  consists  of  104  of  metal,  and  8  of 
oxygen — its  prime  equivalent  being  112, 
upon  the  hydrogen  scale;  and  it  is  the 
base  of  all  the  salts  of  lead.  3.  The  plum- 
beous suroxide  of  Berzelius,  the  sesqui- 
oxide  of  some  British  chemists,  is  the 
well-known  pigment  called  red  lead  or 
minium.  It  consists  of  100  parts  of  metal 
and  10  of  oxygen.  4.  The  plumbic  sur- 
oxide of  Berzelius,  or  the  peroxide  of  the 
British  chemists,  is  obtained  by  putting 
red  lead  in  chlorine  water,  or  in  dilute 
nitric  acid.  It  is  of  a  dark  brown,  almost 
black  color,  which  gives  out  oxygen  when 
heated,  and  becomes  yellow  oxide.  It 
kindles  sulphur  when  triturated  with  it. 
This  oxide  is  used  by  the  analytical  che- 
mist to  separate,  by  condensation,  the 
sulphurous  acid  existing  in  a  gaseous 
mixture. 

Among  the  ores  of  lead  some  have  a 
metallic  aspect;  are  black  in  substance, 
as  well  as  when  pulverized;  others  have 
a  stony  appearance,  and  are  variously 
colored,  with  usually  a  vitreous  or  greasy 
lustre.  The  specific  gravity  of  the  latter 
ores  is  always  less  than  5.  The  whole  of 
them,  excepting  the  chloride,  become 
more  or  less  speedily  black,  with  sul- 
phureted  hydrogen  or  with  hydrosul- 
phurets;  and  are  easily  reduced  to  the 
metallic  state  upon  charcoal,  with  a  flux 
of  carbonate  of  soda,  after  they  have  been 
properly  roasted.  They  diffuse  a  whitish 
or  yellowish  powder  over  the  charcoal, 
which,  according  to  the  manner  in  which 
the  flame  of  the  blowpipe  is  directed 
upon  it,  becomes  yellow  or  red  ;  thus  in- 
dicating the  two  characteristic  colors  of 
the  oxides  of  lead. 

The  lead  ores  most  interesting  to  the 
arts  are: — 

1.  Galena,  sulphuret  of  lead  (See  Ga- 
lena.) This  ore  has  the  metallic  lustre  of 
lead  with  a  crystalline  structure  deriv- 
able from  the  cube.  When  heated  cau- 
tiously at  the  blowpipe  it  is  decomposed, 
the  sulphur  flies  off,  and  the  lead  is  left 
alone  in  fusion  ;  but  if  the  heat  be  con- 
tinued, the  colored  surface  of  the  char- 
coal indicates  the  conversion  of  the  lead 
into  its  oxides.  Galena  is  a  compound  of 
lead  and  sulphur,  in  equivalent  propor- 
tions, and  therefore  consists,  in  100  parts, 
of  865  of  metal,  and  13J  of  sulphur,  with 
which  numbers  the  analysis  ot  the  galena 
of  Clausthal  by  Westrumb  exactly  agrees. 
Its  specific  gravity,  when  pure,  is  7*56. 
Its  color  is  blackish  gray,  without  any 
shade  of  red,  and  its  powder  is  black, 
characters    which    distinguish    it   from 


blende  or  sulphuret  of  zinc.  Its  structure 
in  mass  is  lamellar,  passing  sometimes 
into  the  fibrous  or  granular,  and  even 
compact.  It  is  brittle.  The  specular 
galena,  so  called  from  its  brightly  polish- 
ed aspect,  is  remarkable  for  forming  the 
slicken&ides  of  Derbyshire — thin  seams, 
which  explode  with  a  loud  noise  when 
accidentally  scratched  in  the  mine. 

The  argentiferous  galena  has  in  general 
all  the  external  characters  of  pure  galena. 
The  proportions  of  silver  vary  from  one- 
fifth  part  of  the  whole,  as  at'Tarnowitz, 
in  Silesia,  to  three  parts  in  ten  thousand, 
as  in  the  ore  called  by  the  German  miners 
Weisgultigerz ;  but  it  must  be  observed, 
that  whenever  this  lead  ore  contains  above 
5  per  cent,  of  silver,  several  other  metals 
are  associated  with  it.  The  mean  pro- 
portion of  silver  in  galena,  or  that  which 
makes  it  be  considered  practically  as  an 
argentiferous  ore,  because  the  silver  may 
be  profitably  extracted,  is  about  two  parts 
in  the  thousand.  (See  Silver.)  The 
above  rich  silver  ores  were  first  observed 
in  the  Freyberg  mines,  called  Himmels- 
furst  and  Beschertglnck,  combined  with 
sulphuret  of  antimony ;  but  they  have 
been  noticed  since  in  the  Hartz,  in  Mex- 
ico, and  several  other  places.  It  is  the 
most  abundant  lead  ore  in  the  United 
States,  occupying  an  immense  tract  of 
country  on  the  Missouri  River. 

The  antimonial  galena  (Bournonite) 
exhales  at  the  blowpipe  the  odor  peculiar 
to  antimony,  and  coats  the  charcoal  with 
a  powder  partly  white  and  partly  red. 
It  usually  contains  some  arsenic. 

2.  The  Seleniuret  of  lead  resembles 
galena,  but  its  tint  is  bluer.  At  the  blow- 
pipe it  exhales  a  very  perceptible  smell  of 
putrid  radishes.  Nitric  acid  liberates  the 
selenium.  When  heated  in  a  tube,  oxide 
of  selenium  of  a  carmine  red  rises  along 
with  selenic  acid,  white  and  deliquescent. 
The  specific  gravity  of  this  ore  varies 
from  6-8  to  7-69. 

3.  Native  minium  or  red  lead  has  an 
earthy  aspect,  of  a  lively  and  nearly  pure 
red  color,  but  sometimes  inclining  to 
orange.  It  occurs  pulverulent,  and  also 
compact,  with  a  fracture  somewhat  la- 
mellar. When  heated  at  the  blowpipe 
upon  charcoal,  it  is  readily  reduced  to 
metallic  lead.  Its  specific  gravity  varies 
from  4-6  to  8*9.    This  ore  is  rare. 

4.  White  lead,  carbonate  of  lead. — This 
ore,  in  its  purest  state,  is  colorless  and 
transparent  like  glass,  with  an  adaman- 
tine lustre.  It  may  be  recognized  by  the 
following  characters  :— 

Its  specific  gravity  is  from  6  to  6*7 ; 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


it  dissolves  with  more  or  less  ease,  and 
with  effervescence,  in  nitric  acid;  be- 
comes immediately  black  by  the  action  of 
sulphureted  hydrogen,  and  melts  on 
charcoal  before  the  blowpipe  into  a  button 
of  lead.  According  toKlaproth,  the  car- 
bonate of  Leadhills  contains  82  parts  of 
oxide  of  lead,  and  16  of  carbonic  acid,  in 
98  parts.  This  mineral  is  tender,  scarcely 
scratches  calc-spar,  and  breaks  easily 
with  a  waved  conchoidal  fracture.  It 
possesses  the  double  refracting  property 
m  a  very  high  degree  ;  the  double  image 
being  very  visible  on  looking  through 
the  Sat  faces  of  the  prismatic  crystals. 
Its  crystalline  forms  are  very  numerous, 
and  are  referrible  to  the  octahedron,  and 
the  pyramidal  prism.  This  ore  has  been 
found  very  sparingly  in  the  United 
States. 

5.  Vitreous  lead,  or  sulphate  of  lead. — 
This  mineral  closely  resembles  carbonate 
of  lead  ;  so  that  the  external  characters 
are  inadequate  to  distinguish  the  two. 
But  the  following  are  sufficient.    When 

fmre,  it  has  the  same  transparency  and 
ustre.  It  does  not  effervesce  with  nitric 
acid  ;  it  is  but  feebly  blackened  by  sul- 
phureted  hydrogen  ;  it  first  decrepitates 
and  then  melts  before  the  blowpipe  into 
a  transparent  glass,  which  becomes  milky 
as  it  cools.  By  the  combined  action  of 
heat  and  charcoal,  it  passes  first  into  a 
red  pulverulent  oxide,  and  then  into 
metallic  lead.  It  consists,  according  to 
Klaproth,  of  71  oxide  of  lead,  25  sulphuric 
acid,  2  water,  and  1  iron.  That  specimen 
was  from  Anglesea;  the  Wanlockhead 
mineral  is  free  from  iron.  The  prevailing 
form  of  crystallization  is  the  rectangular 
octahedron,  whose  angles  and  edges  are 
variously  modified.  The  sulphato-car- 
bonate,  and  sulphato-tricarbonate  of 
lead,  now  called  Leadhillite,  are  rare  min- 
erals which  belong  to  this  head. 

6.  Phosphate  of lead.— This,  like  all  the 
combinations  of  lead  with  an  acid,  ex- 
hibits no  metallic  lustre,  but  a  variety  of 
colors.  Before  the  blowpipe  upon  char- 
coal, it  melts  into  a  globule  externally 
crystalline,  which,  by  a  continuance  of 
the  heat,  with  the  addition  of  iron  and 
boracic  acid,  affords  metallic  lead.  Its 
constituents  are  80  oxide  of  lead,  18 
phosphoric  acid,  and  1*6  muriatic  acid, 
according  to  Klaproth's  analysis  of  the 
mineral  from  Wanlockhead.  The  con- 
stant presence  of  muriatic  acid  in  the 
various  specimens  examined  is  a  remark- 
able circumstance.  The  crystalline  forms 
are  derived  from  an  obtuse  rhomboid. 
Thosphate  of  lead  is  a  little  harder  than 


white  lead ;  it  is  easily  scratched,  and  its 
powder  is  always  gray.  Its  specific  gra- 
vity is  6-9.  It  has  a  vitreous  lustre,  some- 
what adamantine.  Its  lamellar  texture 
is  not  very  distinct ;  its  fracture  is  wavy, 
and  it  is  easily  frangible.  The  phos- 
phoric and  arsenic  acids  being,  according 
to  M.  Mitscherlich,  isomorphous  bodies, 
may  replace  each  other  in  chemical  com- 
binations in  every  proportion,  so  that  the 
phosphate  of  lead  may  include  any  pro- 
portion, from  the  smallest  fraction  of 
arsenic  acid  to  the  smallest  fraction  of 
phosphoric  acid,  thus  graduating  inde- 
finitely into  arseniate  of  lead.  The  yel- 
lowish variety  indicates,  for  the  most 
part,  the  presence  of  arsenic  acid.  This 
ore  occurs  at  the  lead  mine  near  Frey- 
burg,  in  Maine.  It  is  also  found  in 
Tennessee. 

7.  Muriate  of  lead.  Horn-lead,  or 
murio-carbonate. — This  ore  has  a  pale 
yellow  color,  is  reducible  to  metallic  lead 
by  the  agency  of  soda,  and  is  not  altered 
by  the  hydrosnlphurets.  At  the  blow- 
pipe it  melts  first  into  a  pale  yellow  trans- 
parent globule,  with  salt  of  phosphorus 
and  oxide  of  copper;  and  it  manifests  the 
presence  of  muriatic  acid  by  a  bluish 
flame.  It  is  fragile,  tender,  softer  than 
carbonate  of  lead,  and  is  sometimes  almost 
colorless,  with  an  adamantine  lustre. 
Spec,  grav.,  606.  Its  constituents,  ac- 
cording to  Berzelius,  are  lead,  25-84; 
oxide  of  lead,  57-07  ;  carbonate  of  lead, 
6-25;  chlorine,  8-84.  silica,  1-46;  water, 
0-54  ;  in  100  parts.  The  carbonate  is  an 
accidental  ingredient,  not  being  in  equiv- 
alent proportion.  Klaproth  found  chlo- 
rine, 13-67;  lead,  39-98;  oxide  of  lead, 
22-57  ;  carbonate  of  lead,  23-78. 

8.  Arseniate.  of  lead. — Its  color  of  a 
pretty  pure  yellow,  bordering  slightly  on 
the  greenish,  and  its  property  of  exhaling 
by  the  joint  action  of  fire  and  charcoal  a 
very  distinct  arsenical  odor,  are  the  only 
characters  which  distinguish  this  ore 
from  the  phosphate  of  lead.  The  form  of 
the  arseniate  of  lead,  when  it  is  crystal- 
lized, is  a  prism  with  six  faces,  of  the 
same  dimensions  as  that  of  phosphate  of 
lead.  When  pure,  it  is  reducible  upon 
charcoal,  before  the  blowpipe,  into 
metallic  lead,  with  the  copious  exhala- 
tion of  arsenical  fumes.  Its  spec,  prrav. 
is  5-05.  It  consists  of  oxide  of  lead,  77*5 ; 
arsenic  acid,  12-5;  phosphoric  acid,  7-5; 
hydrochloric  acid,  1*5. 

9.  Molyhate  of  lead,,  or  yeUotv  lead,  is 
found  at  Southampton,  Mass.  It  occurs 
in  obtuse  octohedrons  and  tabular  crys- 
tab.     Spec.  grav.   5-05.    It  consists  of 


304 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


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58-4  oxide  of  lead,  38  rnolybdic  acid,  and 
2*08  oxide  of  iron. 

The  foregoing  are  the  most  common 
ores  of  lead,  all  of  which,  except  the  chro- 
mate  and  molybdate,  are  used  to  procure 
metallic  lead.  It  is,  however,  from  the 
sulphuret  (galena)  that  the  great  bulk  of 
the  lead  of  commerce  is  obtained.  Under 
the  article  Metallurgy  the  treatment  of 
lead  ores  is  noticed,  and  it  may  therefore 
be  here  merely  stated  that  the  chief  object 
to  attain,  after  having  procured  a  clean 
ore,  is  to  get  rid  of  the  sulphur — which 
may  be  accomplished  either  by  roasting 
in  the  open  air  or  in  reverberating  furna- 
ces. In  this  way  the  sulphur  is  volatiliz- 
ed, and  the  lead,  either  as  oxide  or  re- 
duced to  the  state  of  metal,  runs  into  the 
basin  or  crucible  of  the  furnace  when  it 
is  deoxidized  by  being  kept  in  contact 
with  ignited  charcoal.  In  Germany  and 
France  another  mode  is  adopted,  which 
consists  in  throwing  into  the  reverberat- 
ing furnace  28  per  cent,  of  old  iron.  In 
a  short  time  the  sulphur  leaves  the  lead 
and  passes  over  to  the  iron,  and  the  lead 
is  in  the  state  of  pure  metal  in  the  bot- 
tom of  the  furnace.  This  plan  saves 
time  and  labor,  but  the  iron  is  lost.  Its 
value,  however,  is  trifling. 

The  uses  of  lead  and  its  oxides  are  very 
numerous :  the  latter  as  paints,  chiefly, 
and  the  former  in  roofing,  and  as  gutters, 
cisterns,  and  pipes.  For  these  this  me- 
tal has  many  advantages  ;  it  is  soft  and 
malleable,  so  that  two  edges  may  be  fold- 
ed over  and  hammered  water-tight  with- 
out soldering ;  this  prevents  rupture  from 
expansion,  which  uften  occurs  in  solder- 
ed vessels.  As  a  means  of  carrying  wa- 
ter it  is  in  constant  use,  though  liable  to 
many  objections.  The  metal,  when  pure, 
is  perfectly  insoluble  in  water,  but  the 
oxide  and  carbonate  of  lead  are  soluble  in 
water  containing  an  excess  of  carbonic 
acid.  When  water  runs  through  a  lead 
pipe  it  oxidizes  it  in  a  very  short  time, 
forming  a  white  or  yellow  crust  on  the 
inside.  This  dissolves  to  a  small  extent 
in  the  water,  and  this  latter,  when  drank, 
produces  all  the  symptoms  of  poisoning 
by  lead.  On  this  account,  lead  pipes  have 
been  superseded  by  iron,  zinc,  gutta  per- 
cha,  and  glass  pipes.  Dr.  Christison  has 
shown,  that  the  purer  the  water,  that  is 
the  more  pure  it  is  from  saline  matters, 
the  greater  is  the  corrosion  of  the  pipe 
and  the  amount  of  lead  dissolved  :  but 
that  if  the  water  contain  much  saline  mat- 
ter, especially  sulphates,  the  lead  is  pre- 
cipitated out  of  the  water  and  no  injury 
can  arise.    He  recommended  that  new 


I  leaden  pipes  should  be  plugged  up  for  a 
I  few  days  with  a  solution  ol  sulphate  of 
I  soda  or  phosphate  of  soda  until  the  whole 
!  inside  of  the  pipe  was  coated  with  a  crust 
|  of  sulphate  or  phosphate  of  lead,  which 
j  effectually  protects  the    pipe    from  any 
!  further  action.    If  this  cannot  be  conve- 
:  niently  done,  a  zinc  cistern  may  be  used 
j  to  receive  the  water  which  has  flowed 
I  through  the  pipe  :  after  having  lain  a  few 
|  hours,  the  lead  present  in  the  water  will 
!  be  thrown  down  as  a  dark  powder  on  the 
j  surface  of  the  zinc.    Should  this  plan  not 
be  adopted,  the  water  should  be  allowed 
to  run  freely  through  the  pipes  for  *wo 
days  before  it  be  applied  to  any  domei  tic 
purpose.    Vessels  of  lead  should  never 
be  used  for  culinary  or  dairy  purposes. 
Lead  is  used  for  making  shot  and  solder. 
It  forms  an  imperfect  alloy  with  copper. 
The  common  brass  cocks  is  an  alloy  of 
these  two  metals.    The  union  is,  how- 
ever, so  partial,  that  on  heating  the  cock 
the  lead  melts  out  and  leaves  the  copper. 
This  process  is  called  liquation.     The 
nitrate  of  lead  is  made  by  heating  the  me- 
tal with  warm  nitric  acid, — a  crude  and 
weak  solution  of  this  salt  of  lead,  consti- 
tuted the  disinfecting  liquid  of  Ledoyen 
&  Calvert,  which  has  been  so  preposter- 
ously overrated.    It  is  capable  of  decom- 
posing animal  sulphurets,  phosphurets, 
and  hence  of  removing  the  unpleasant 
smells  of  drains  and  water-closets,   but 
beyond  this  action  it  has  hardly  any,  and 
it  is  quite  incapable  of  breaking  up  and 
rendering  innocuous  a  miasm  in  the  way 
in  which  chlorine  does.    Calvert  fell  a 
victim  to  his  trials  of  this  solution  in  the 
Fever  Hospitals  in  Canada. 

Lead  constituted  the  writing-table  of 
the  ancient  Greeks  and  Eomans. 

When  metallic  lead  is  strongly  heated 
in  the  reverberatory  furnace  it  beomes  of 
a  dull  color  on  the  surface,  loses  its  me- 
tallic appearance,  and  puts  on  the  appear- 
ance ot  a  dross  or  powder.  When  this 
dross  is  heated  to  a  low  ignition,  it  be- 
comes of  a  dull  yellow  color,  and  is  called 
common  massicot ;  and,  by  a  higher  heat 
and  longer  exposure  to  the  air,  it  as- 
sumes a  deeper  yellow,  and  is  then  called 
massicot.  This  is  the  protoxide  of  lead. 
and  consists,  in  112  parts,  of  104  lead  and 
8  oxygen.  When  it  contains  about  four 
per  cent,  of  carbonic  acid2  it  is  called  li- 
tharge. It  unites  with  acids,  and  is  the 
base  of  all  the  salts  of  lead.  If  the  pro- 
toxide, or  metallic  lead,  be  subjected, 
during  48  hours,  to  the  heat  of  a  rever- 
j  beratory  furnace,  it  passes  to  the  condi- 
I  tion  of  red  oxide,  or  what  is  commonly 


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CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


305 


called  minium,  or  red  lead.  Its  composi- 
tion is,  in  116  parte,  104  lead,  12  oxygen. 
Lead  forms  a  compound  with  chlorine. 
The  union  is  effected  by  adding  muriatic 
acid,  or  a  solution  of  common  salt,  to  the 
acetate  or  nitrate  of  lead  dissolved  in  wa- 
ter. This  chloride  fuses  at  a  temperature 
below  redness,  and  forms,  as  it  cools,  a 
semi-transparent  horny  mass,  sometimes 
called  horn  lead. 

The  pigment  called  mineral,  or  patent 
yellow,  is  a  compound  of  the  chloride  and 
protoxide  of  lead.  It  is  prepared  for  the 
purposes  of  the  arts  by  the  action  of 
moistened  sea-salt  on  litharge,  by  which 
means  a  portion  of  the  protoxide  is  con- 
verted into  chloride. 

White-lead,  or  carbonate  of  lead,  is 
prepared  by  exposing  narrow  slips,  or 
thin  lead,  to  the  steam  of  vinegar,  in  a 
close  vessel.  The  slips  are  laid  on  bars 
of  wire  above  the  surface  of  the  boiling 
vinegar.  For  flake-white,  dilute  sulphu- 
ric acid  is  preferred. 

There  is,  (says  Thomson.)  only  one 
direct  poison  among  the  salts  of  lead, 
which  is  the  carbonate  ;  and,  when  the 
other  salts  of  lead  display  poisonous  ef- 
fects, these  are  to  be  attributed  either 
wholly,  or  in  part,  to  their  conversion 
into  the  carbonate.  This  salt  acts  as  a 
powerful  sedative  astringent  on  the  liv- 
ing system,  diminishing  the  nervous  en- 
ergy, and,  consequently,  greatly  depress- 
ing the  powers  of  the  circulation,  and 
lowering  the  tone  of  the  muscular  system. 
It  is  probably  taken  into  the  blood,  which 
may  account  for  its  slow  operation  when 
it  is  introduced  into  the  stomach  in  mi- 
nute doses,  for  a  considerable  length  of 
time,  and  also  for  its  producing  similar 
effects,  when  applied  to  the  surface  of 
the  body  denuded  of  the  cuticle,  or  in  a 
state  of  ulceration. 

Great  mischief  has  been  produced  by 
the  use  of  lead  in  dairies.  If  the  milk 
runs  into  the  slightest  acidity,  some  lead 
will  be  dissolved,  and  injurious  conse- 
quences will  follow  if  it  is  taken  into  the 
stomach. 

Lead  in  Wines  is  detected  by  a  black 
precipitate,  which  will  be  instantly  pro- 
duced by  the  following  mixture  : — Ex- 
pose equal  parts  of  sulphur  and  powder- 
ed oyster-shells  to  a  white  heat  for  a 
quarter  of  an  hour.  When  cold,  add  an 
equal  quantity  of  cream  of  tartar,  and 
boil  them  with  water  in  a  strong  bottle 
for  an  hour.  Transfer  to  ounce  phials, 
and  add  to  each  20  drops  of  muriatic 
acid. 


To  reduce  Red  Lead.  Heat  in  a  Hessian 
crucible  2  oz.  of  red  lead  with  2  drs.  of 
powdered  charcoal,  and  1  oz.  of  common 
salt.  The  result  will  be  2  oz.  of  pure  me- 
tal. 

When  nitrate  of  lead  or  of  bismuth  is 
boiled  with  carbonate  of  lime,  magnesia, 
or  barytes,  these  salts  are  decomposed, 
and  the  oxides  are  so  completely  precipi- 
tated that  hydrosulphuret  of  ammonia 
shows  no  traces  of  them  in  the  solution. 
Carbonate  of  lime,  when  added  to  a  cold 
solution  of  these  metals,  precipitates  only 
the  oxide  of  bismuth.  Several  methods 
have  been  proposed  for  separating  the 
lead  which  is  contained  in  the  bismuth  of 
commerce ;  but  carbonate  of  lime  is  pre- 
ferable. 

LEAD,  BLACiv,    See  Plumbago. 

LEAD,  eok  Sounding.  The  common 
hand  lead  weighs  11  lbs.  with  about  20 
fathoms  of  line.  The  leadsman  stands 
somewhere  on  the  side  of  the  vessel, 
leaning  against  a  band  for  the  purpose  : 
lets  the  lead  descend  near  the  water ; 
then,  swinging  it  over  his  head  once,  or 
twice,  if  the  ship  is  going  fast,  throws  it 
forward.  The  line  is  marked  at  5,  7,  10, 
13,  17,  and  20  fathoms.  The  numbers 
between  are  called  deeps  ;  thus,  u  by  the 
mark  7,"  "  by  the  deep  nine,"  indicates 
7  and  9  fathoms. 

When  the  depth  is  great,  the  deep-sea 
lead  of  28  lbs.  is  used.    The  lead  is  drop- 

J>ed  from  the  fore  part  of  the  vessel,  the 
ine  being  passed  outside  all.  It  is  ge- 
nerally necessary  to  heave  the  ship  to. 

LEAD-SHOT.  The  origin  of  most  of 
the  imperfections  in  the  manufacture  of 
lead-shot  is  the  too  rapid  cooling  of  the 
spherules  by  their  being  dropped  too  hot 
into  the  water,  whereby  their  surfaces 
form  a  solid  crust,  while*their  interior  re- 
mains fluid;  and,  in  its  subsequent  con- 
cretion, shrinks,  so  as  to  produce  the  ir- 
regularities of  the  shot. 

The  patent  shot  towers  obviate  this 
evil,  by  exposing  the  fused  spherules 
after  they  pass  through  the  cullender,  to 
a  large  body  of  air  during  their  descent 
into  the  water  tub  placed  on  the  ground. 
The  greatest  erection  of  this  kind  is  pro- 
bably at  Villach,  in  Carinthia,  being  240 
Vienna,  or  249  English  feet  high. 

The  quantity  of  arsenic  added  to  the 
mass  of  melted  lead,  varies  according  to 
the  quality  of  this  metal ;  the  harder  and 
less  ductile  the  lead  is,  the  more  arsenic 
must  be  added.  About  3  pounds  of  either 
white  arsenic  or  orpiment  is  enough  for 
one  thousand  parts  of  soft  lead,  and  about 


306 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


[leq 


8  for  the  coarser  kinds.  The  latter  are 
employed  preferably  for  shot,  as  they  are 
cheaper  and  answer  sufficiently  well. 
The  arsenical  alloy  is  made  either  by  in- 
troducing some  of  this  substance  at  each 
melting,  or  by  making  a  quantity  of  the 
compound  considerably  stronger  at  once, 
and  adding  a  certain  portion  of  this  to 
each  charge  of  lead.  If  the  particles  of 
the  shot  appear  lens-shaped,  it  is  a  proof 
that  the  proportion  of  arsenic  has  been 
too  great ;  but  if  they  are  flattened  upon 
one  side,  if  they  are  hollowed  in  their 
middle,  called  cupping  by  the  workman, 
or  drag  with  a  tail  behind  them,  the  pro- 
portion of  arsenic  is  too  small. 

The  following  is  the  process  prescribed 
by  the  patentees,  Ackerman  and  Martin. 
Melt  a  ton  of  soft  lead,  and  sprinkle 
round  its  sides,  in  the  iron  pot,  about  two 
shovelfuls  full  of  wood  ashes,  taking  care 
to  leave  the  centre  clear ;  then  put  into 
the  middle  about  40  pounds  of  arsenic,  to 
form  a  rich  alloy  with  the  lead.  Cover 
the  pot  with  an  iron  lid,  and  lute  the  joints 
quickly  with  loam  or  mortar,  to  confine 
the  arsenical  vapors,  keeping  up  a  mode- 
rate fire  to  maintain  the  mixture  fluid  for 
three  or  four  hours ;  after  which  skim 
carefully,  and  run  the  alloy  into  moulds 
to  form  ingots  or  pigs.  The  composition 
thus  made"  is  to  be  put  in  the  proportion 
of  one  pis:  or  ingot  into  1000  pounds  of 
melted  ordinary  lead.  When  the  whole 
is  well  combined,  take  a  perforated  skim- 
mer and  let  a  few  drops  of  it  fall  from 
some  height  into  a  tub  of  water.  If  they 
do  not  appear  globular,  some  more  arseni- 
cal alloy  must  be  added. 

Lead  which  contains  a  good  deal  of 
pewter  or  tin  must  be  rejected,  because 
it  tends  to  produce  elongated  drops  or 
tails. 

LE  ATH  ER .    See  Tanning. 

LEATHER  (Varnished  French,  man- 
ufacture of).  This  process  consists  of 
two  operations  : — First,  the  preparation 
of  the  skin,  described  under  the_  head 
Tanning  ;  and,  second,  the  varnishing  of 
the  leather  thus  dressed.  In  the  prepa- 
ration of  the  leather,  linseed  oil,  made  to 
dry  quick  by  means  of  metallic  oxides  and 
salt,  is  employed  as  the  basis.  For  each 
twenty-two  gallons  of  linseed  oil,  twenty- 
two  lbs.  of  white  lead  and  twenty-two  lbs. 
of  litharge  are  employed,  and  the  oil  boil- 
ed with  those  ingredients  until  it  has  at- 
tained the  consistency  of  syrup.  This 
preparation,  mixed  either  with  chalk,  or 
ochres,  is  applied  to  leather  by  means  of 
appropriate  tools,  and  well  worked  into  the 


pores  ;  three  or  four  layers  are  applied  in 
succession,  taking  care  to  dry  each  layer 
thoroughly  before  the  application  of  the 
next  coating.  Four  or  five  coatings  of  the 
dried  linseed  oil,  without  the  admixture 
of  the  earthy  substances,  are  then  given ; 
the  addition  of  very  fine  ivory  black  and 
some  oil  of  turpentine  is  usually  made  to 
the  oil.  These  coatings  are  put  on  very 
thin,  and  when  carefully  dried  the  leather 
is  rubbed  over  with  fine  pumice  stone 
powder  to  render  the  surface  perfectly 
smooth  and  even,  for  the  reception  of  the 
varnish.  The  varnish  is  composed  as 
follows: — Ten  lbs.  of  oil  prepared  as 
above,  half  a  lb.  of  asphalt  or  Jewish  bitu- 
men, five  lbs.  of  copal  varnish,  and  ten 
lbs.  of  turpentine.  The  oil  and  asphalt 
are  first  boiled  together,  the  copal  var- 
nish and  turpentine  added  afterward,  and 
the  mixture  well  stirred.    Instead  of  as- 

Ehalt,  Prusian  blue  or  Ivory  black  may 
e  employed.  This  varnish  must  be  kept 
in  a  warm  place  for  two  or  three  weeks 
before  it  is  fit  for  use.  The  greatest  pos- 
sible care  must  be  taken  both  before  and 
during  the  application  of  the  varnish  to 

?>revent  the  adherence  of  any  dust  to  the 
eather.  The  leather,  when  varnished, 
must  be  put  into  drying  stoves,  heated  to 
about  200  degrees  or  more,  according  to 
the  nature  of  the  leather  and  the  varnish 
employed. 

LEECH,  ARTIFICIAL.  Dr.  Charles 
Rodgers,  of  Jefferson,  Wisconsin,  has  in- 
vented a  most  ingenious  little  instrument 
as  a  substitute  for  the  common  cupping 
process,  and  as  an  artificial  leech.  In  the 
first  place  the  inflamed  part  of  the  patient, 
or  on  whatever  part  on  which  it  is  de- 
signed to  operate,  is  perforated  in  one  or 
more  places  by  a  lancet,  impelled  in  a  tube 
by  blowing  it  like  a  Guinea  arrow  with 
the  mouth.  The  artificial  leech  consists 
of  a  glass  tube,  which  is  set  upon  the 
wound,  and  by  a  small  metal  tube  at  the 
other  end,  all  the  air  is  exhausted,  when 
the  blood,  &c,  rises  in  the  vacuum,  and 
communication  is  then  cut  off  from  the 
atmosphere  by  an  ingenious  slide  valve, 
which  stops  the  mouth  of  the  small  me- 
tal tube.  This  invention  is  a  neat  im- 
provement in  the  art  of  surgery.  Mea- 
sures have  been  taken  to  secure  a  patent. 
It  appears  to  be  similar  to  the  artificial 
leech  of  Alexander,  in  London. 

LEGHORN  HATS.  It  is  chiefly  in 
the  neighborhood  of  Florence,  Pisa,  the 
district  of  Sienna,  and  in  the  upper  part 
of  the  valley  of  the  Arno,  that  the  best 
platting  is  made  for  straw  hats.  The  straw 


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CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


307 


used  in  working  these  hats  is  grown  in 
districts  mountainous  and  sterile.  It  is 
produced  from  a  kind  of  wheat,  of  which 
the  grain  is  very  small.  This  straw, 
though  slender,  has  nrnch  consistence, 
and  the  upper  part  of  the  stalk  being  per- 
fectly hollow,  is  easily  dried.  It  is  pulled 
out  of  the  earth  before  the  grain  begins 
to  form.  After  being  freed  from  the 
soil,  which  adheres  to  the  root,  it  is  form- 
ed into  small  sheaves,  to  be  winnowed ; 
the  part  above  the  last  joint  of  the  stem 
is  then  plucked  off,  which  is  from  four  to 
six  inches  long,  the  ear  remaining  attach- 
ed to  it.  This  being  done,  it  is  bleached 
by  the  dew  and  the  sunshine.  Eain  is 
very  injurious  to  it,  and  destroys  much 
of  its  whiteness.  The  lower  parts  of  the 
straw  are  treated  in  the  same  manner,  and 
employed  in  forming  hats  of  an  inferior 
quality.  The  upper  parts,  torn  off  just 
to  the  knot,  are  sorted  according  to  their 
degree  of  fineness.  This  stapling  is  made 
with  much  care,  and  usually  affords  straw 
of  three  different  prices.  A  quantity  of 
straw,  worth  8  cents,  after  having  under- 
gone this  process,  is  sold  for  $1*25.  The 
tress  is  formed  of  seven  or  nine  straws, 
which  are  begun  at  the  lower  end,  and  are 
consumed,  in  platting,  to  within  an  inch 
and  a  half  of  the  upper  extremity,  includ- 
ing the  ear.  All  the  ends  of  the  straws  that 
have  been  consumed  are  left  out,  so  that, 
the  ears  are  on  the  other  side  of  the  tress. 
As  fast  as  it  is  worked,  it  is  rolled  on  a  cy- 
linder of  wood.  When  it  is  finished,  the 
projecting  ends  and  ears  are  cut  off;  it  is 
then  passed  with  force  between  the  hand 
and  a  piece  of  wood,  cut  with  a  sharp 
edge,  to  press  and  polish  it.  The  tresses 
thus  prepared  are  so  used  that  a  complete 
hat  shall  be  formed  of  one  piece.  They 
are  sewed  together  with  raw  silk.  The 
diameter  of  the  hat  is  in  general  the  same  ; 
the  only  difference  consists  in  the  degree 
of  fineness,  anu,  consequently,  the  num- 
ber of  turns  which  the  tress  has  made  in 
completing  the  hat ;  some  having  from 
twenty  to  eighty  such  turns. 

LEMON  (Citrus).  One  species  of  the 
genus,  of  which  orange  is  another.  The 
outer  rind  contains  a  fragrant  oil.  The 
juice  is  a  very  refreshing  modification 
of  citric  acid  with  mucilage,  sugar,  and 
water.  The  trees  produce  thousands  of 
the  fruit.  To  keep,  the  juice  is  crystal- 
lized, and.  when  wanted,  dissolved  in  any 
liquid.  The  essential  oil  is  produced  by 
distillation  with  water  and  alcohol. 

Lemon  Drops.  Mix  £  lb.  of  sugar  with 
3  drs.  of  salt  of  sorrel  in  a  little  water, 
boil,  add  i  lb.  more  sugar,  and  8  drops 


of  essence  of  lemon ;  or,  (tartaric  acid,  and 
citric  acid,  for  the  sorrel-salt,  and  le- 
mon) ;  then  with  a  crooked  wire  draw  it 
out  in  drops  on  a  slab. 

Lemonade  Powders.  Mix,  and  divide 
into  24  parts,  6  oz.  of  sugar,  10  drops  of 
essence  of  lemon,  and  1  oz.  of  tartaric 
acid. 

LENS.  In  Optics,  a  thin  piece  of  glass 
or  any  other  transparent  substance, 
bounded  on  both  sides  by  polished  spher- 
ical surfaces,  or  on  the  one  side  W  a 
spherical  and  on  the  other  by  a  plain 
surface  ;  and  having  this  property,  that 
parallel  rays  of  light,  in  passing  through 
it,  have  their  direction  changed,  so  as  to 
converge  to  a  given  point,  called  the 
principal  focus  of  the  lens,  or  to  diverge 
as  if  they  proceeded  from  that  point. 

Lenses  are,  in  fact,  mere  multiplying- 
glasses,  with  an  infinite  number  of  sides, 
producing  an  infinite  number  of  images, 
whose  visual  resultant  is  one  blended  fig- 
ure, expanded  over  the  whole  visual  angle 
of  the  glass,  in  length  and  in  breadth, 
and  therefore  said  to  be  magnified.  The 
images  produced  by  the  inclined  or  ob- 
lique sides,  owing  to  unequal  refractions, 
are  however  highly-colored  in  the  focus  ; 
and,  owing  to  the  unequal  inclinations  of 
the  spherical  form,  the  rays  do  not  all 
converge  exactly  to  the  same  point.  Len- 
ses have  therefore  been  very  properly  com- 
posed of  two  kinds  of  glass,  which  re- 
fract differently  or  unequally,  and  then, 
by  combining  a  convex  and  a  concave, 
the  inequality  is  destroyed,  and  the  im- 
age free  from  color.  The  forms  too  have 
been  varied  from  the  spherical  to  the 
parabolic,  with  a  view  to  concentrate  the 
rays  in  one  point.  Lenses  are  manufac- 
tured writh  great  precision,  by  steam 
power,  by  Jenkins's  machine,  fixed  in 
concave  basins,  and  the  friction  proceeds 
on  some  hundreds  at  the  same  time. 

A  spherical  lens,  shown  at  A,  is  a 
sphere  or  globule  of  glass. 

Lenses  receive  different  denominations, 
according  to  their  different  forms. 

A  double  convex  lens,  shown  at  B,  is  a 
solid  formed  by  two  convex  spherical  sur- 
faces ;  and  is  equally  convex  or  unequally 
convex,  according 

as    the    radii    of  ABC 

it3    two   surfaces 
are  equal  or  une-  M 
qual. 

A  plano-convex  lens,  C,  is  that  of  which 
one  of  the  surfaces  is  plane  and  tho  other 
convex. 

A  double  concave  lens,  D,  is  bounded 
by  two  concave  spherical  surfaces,  which 


308 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[lev 


have  either  the  same  or  a  different  cur- 
vature. 

*-;.•■'<«.•:-•"    a  A  plano-con- 

cave lens,  E, 
N  has  one  sur- 
face plane,  and 
the  other  con- 
cave. 

A  meniscus,  F  (so  called  from  its  re- 
semblance to  a  little  moon,)  is  a  lens  of 
which  one  of  the  surfaces  is  convex  and 
the  other  concave,  and  which  meet  if  con- 
tinued. The  radius  of  the  convex  sur- 
face is  consequently  smaller  than  the 
radius  of  the  concavo. 

A  concavo-convex  l-ens,  G,  is  that  of 
which  one  of  the  surfaces  is  concave  and 
the  other  convex ;  but  in  this  case  the 
surfaces  will  not  meet  though  continued, 
the  radius  of  the  concave  surface  being 
smaller  than  that  of  the  convex  one. 

The  straight  line  M  N  which  passes 
through  the  centres  of  all  the  curved  sur- 
faces, or  is  perpendicular  to  both  surfaces 
of  the  same  lens,  is  called  the  axis  of  the 
lens  ;  and  it  is  in  this  line  that  the  focus 
of  the  lens  is  situated. 

It  was  observed,  at  an  early  period,  that 
a  transparent  body  of  a  spherical  form  has 
the  property  of  collecting  at  the  focus  the 
parallel  rays  of  light  which  fali  on  its 
surface.  But  it  was  remarked,  at  the 
same  time,  that  the  illumination  at  these 
foci  was  extremely  feeble,  in  consequence 
of  the  thickness  of  the  glass  which  the 
light  had  to  pass  through.  This  incon- 
venience is  removed  by  taking  only  two 
small  segments  instead  of  the  entire 
sphere  ;  by  which  means,  as  the  refrac- 
tion takes  place  only  at  the  surfaces,  and 
not  in  the  interior  of  the  glass,  the  very 
same  refraction  of  the  rays  is  produced 
as  when  the  whole  sphere  is  used  ;  and 
the  thickness  of  the  glass  being  greatly 
diminished,  the  rays  pass  through  it  in 
much  greater  number,  and  the  intensity 
of  the  light  in  the  focus  is  much  more 
considerable. 

The  rules  for  finding  the  focal  distances 
of  the  different  sorts  of  lenses  are  the 
following.  They  depend  in  some  meas- 
ure on  the  refracting  power  of  the  glass. 
We  shall  here  suppose  the  index  of  re- 
fraction to  be  1  -500. 

Lenses  of  great  power  and  correct  form 
are  made  in  this  country. 

LEVEL.  An  instrument  which  shows 
the  direction  of  a  straight  line  parallel 
to  the  plane  of  the  horizon. 

The  plane  of  the  sensible  horizon  is 
indicated  in  two  ways  :  by  the  direction 
of  the  plummet  or  plumb-line,  to  which 


it  is  perpendicular ;  and  by  the  surface 
of  a  fluid  at  rest.  Accordingly,  levels 
are  formed  either  by  means  of  the  plumb- 
line,  or  by  the  agency  of  a  fluid  applied 
in  some  particular  manner.  They  all  de- 
pend upon  the  same  principle,  namely, 
the  action  of  terrestrial  gravity. 

Levels  in  which  the  plumb-line  forms 
the  essential  part  are  those  most  usually 
employed  for  the  common  purposes  re- 
quired by  bricklayers,  masons,  carpen- 
ters, &c.  They  are  constructed  under 
many  different  forms,  but  the  general 
principle  is  as  follows  :  A  frame  or  board 
is  prepared,  having  one  edge  perfectly 
straight,  and  a  straight  line  is  drawn  on 
the  frame  at  right  angles  to  the  straight 
edge.  To  some  point  of  this  straight 
line  a  thread  canning  a  plummet  is  at- 
tached •  consequently,  when  the  frame  is 
placed  in  such  a  position  that  the  thread 
of  the  plummet,  hanging  freely,  coincides 
with  the  straight  line,  the  straight  edge 
of  the  frame,  which  is  perpendicular  to 
it,  must  be  horizontal.    See  Plummet. 

The  Artillery  Foot  Level,  and  the  Ghin- 
ner"s  Level,  besides  the  line  and  plum- 
met, have  a  scale  for  showing  the  incli- 
nation of  a  straight  line  to  the  horizon. 
The  former  has  two  equal  legs  or  branches 
placed  at  right 
angles  ;  and 
from  their 
point  of  junc- 
tion a  thread 
and  plummet 
hangs,  and  plays  over  a  quadrant  divided 
into  twice  45°  from  the  middle.  The 
plane  or  line  on  which  the  two  ends  rest 
is  horizontal  when  the  thread  falls  over 
the  zero  point  of  the  scale  ;  and  when  it 
falls  over  any  other  point,  the  degree 
marked  on  the  scale  indicates  the  incli- 
nation of  the  line  to  the  horizon.  The 
gunner's  level  is  on  the  same  principle, 
though  differently  constructed  ;  the 
thread  or  plummet  being  replaced  by  a 
solid  piece  of  brass,  loaded  at  the  lower 
end,  and  the  legs,  or  rather  the  edges,  of 
the  brass  plate"  making  an  angle  of  45°. 
It  is  used  in  the  same  manner  as  the 
former. 

Spirit  Level. — By  far  the  most  conven- 
ient and  also  the  most  accurate  level  is 
the  spirit  level,  represented  in  the  an- 
nexed figure;  "which  is  nothing  more 
than  a  glass  tube 
nearly  filled  with 
a  liquid  (spirit  of 
wine  being  now  generally  used,  on  ac- 
count of  its  mobility,  and  not  being  liable 
to  freeze,)  the  bubble  in  which,  when  the 


lev] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


309 


tube  is  placed  horizontally,  would  rest  in- 
differently in  any  part  it'  the  tube  could 
be  made  mathematically  straight ;  but 
that  being  impossible  to  execute,  and 
every  tube  having  some  slight  curvature, 
if  the  convex  side  be  placed  upwards  the 
bubble  will  occupy  the  higher  part,  as  in 
the  figure  (where  the  curvature  is  pur- 
posely exaggerated.) 

The  accuracy  of  the  indications  of  the 
level  depends  in  a  considerable  degree 
on  the  regularity  of  the  interior  surfaces 
of  the  tube.  They  are  commonly  made 
of  glass  tubes  in  the  same  state  as  they 
are  obtained  at  the  glass-house  ;  but  when 
very  great  accuracy  is  required,  as  in  as- 
tronomical observations,  the  interior  sur- 
faces are  sometimes  ground  so  as  to  give 
them  a  regular  cylindrical,  or  rather 
spindle  form,  with  a  slight  spherical  cur- 
vature. The  tube  and  bubble  must  be  of 
considerable  length.  The  larger  the  bub- 
ble, the  more  freely  it  moves,  and  conse- 
quently, the  more  sensible  is  the  level  to 
a  small  inclination.  With  proper  care 
they  can  be  executed,  it  is  said,  with  such 
delicacy  as  to  indicate  a  single  second  of 
angular  deviation  from  exact  horizon- 
tal'ity. 

LEVEE.  In  Mechanics,  an  inflexible 
rod  movable  about  afulcrvm  or  prop,  and 
having  forces  applied  to  two  or  more 
points  in  it.  The  lever  is  one  of  the  me- 
chanical powers  ;  and,  being  the  simplest 
of  them  all,  was  the  first  that  was  attempt- 
ed to  be  explained.  Its  properties  are 
treated  of  by  Aristotle ;  but  the  first  ac- 
curate explanation  was  given  by  Archi- 
medes, in  his  Treatise  De  Equiponderanti- 
bus. 

In  treating  of  the  lever,  it  is  convenient 

to  distinguish  the  forces  applied  to  it  by 

different  names.     One  is  usually  called  the 

power,  the  other  the  weight  or  resistance. 

Fig.  1.  Fig.  2. 


rT 


VQ 


woT3 

Levers  are  commonly  divided  into  three 
kinds,  according  to  the  relative  positions 
of  the  power,  the  weight,  and  the  fulcrum. 
In  a  lever  of  the  first  kind  (fig.  1),  the 
fulcrum  F  is  between  the  power  P  and  the 
weight  W.  In  a  lever  of  the  second  kind, 
Fig.  3  Fig.  4. 


jL 


(fig.  2),  the  weight  W  is  between  the  ful- 
crum F  and  the  power  P.    In  a  lever  of 


the  third  kind  (fig.  3),  the  power  P  is  be- 
tween the  fulcrum  F  and  the  weight  W. 
The  general  principle  of  the  lever  is, 
that  when  the  power  and  weight  are  in 
equilibrio,  they  are  to  each  other  inverse- 
ly as  their  distances  from  the  fulcrum. 
This  property  is  almost  an  obvious  conse- 
quence from  the  principle  of  virtual  ve- 
locities ;  but  it  may  be  deduced  from  more 
familiar  considerations.  Let  A  B  be  a 
cylinder  or  bar  of  homogeneous  matter. 
If  supported  from  the  middle  O,  the  two 
ends  would  evidently  balance  each  other, 
and  the  pressure  at  O  would  be  the  same 
as  if  the  whole  matter  of  the  bar  were  con- 
centrated in  that  point.  Suppose  it  to 
consist  of  two  parts,  A  C  and  B  0,  these 
again  would  be  separately  supported  at 
their  middle  points  D  and  E ;  or  the 
whole  of  the  matter  in  A  C  may  be  con- 
ceived to  be  concentrated  at  D,  and  the 
whole  of  that  in  B  C  at  E,  and  the  equili- 
brium would  not  be  disturbed.  Hence 
the  weight  of  A  C  attached  at  D,  and  the 
weight  of  B  C  attached  at  E,  would  bal- 
ance the  inflexible  line  D  E,  if  supported 
at  O,  the  centre  of  the  whole  bar  A  B. 
But  O  D=A  O— A  D=i  A  B-4  A  C=i 
B  0  ;  and  O  E=0  B— E  B=i  A  B— i  C  B 
=£  A  C  ;  consequently,  O  D  is  to  0  E  as 
B  C  to  A  C ;  or  O  D  is  to  0  E  as  the 
weight  concentrated  at  E  to  the  weight 
concentrated  at  D.  This  demonstration 
is  commonly  ascribed  to  Archimedes. 

This  proposition  shows  the  advantage 
obtained  by  using  the  lever  as  a  mechan- 
ical engine.  The  arm  P  F  (fig.  1),  is  com- 
monly longer  than  W  F,  and,  consequent- 
ly, when  there  is  equilibrium  the  weight 
exceeds  the  power.  The  proportion  in 
which  the  weight  exceeds  the  power  is 
called  the  mechanical  advantage,  or  pur- 
chase. Suppose  P  F  (figs.  1  and  2)=4 
feet,  and  W  F=l  foot ;  then  a  power  of 
1  lb.  acting  atP  will  overcome  a  resistance 
of  4  lbs.  at  W. 

Suppose  the  lever  with  the  weights  P 
and  W  to  turn  round  the  fulcrum,  the 
two  points  to  which  P  and  W  are  attached 
will  describe  arcs  proportional  to  the  radii 
F  P,  F  W  ;  consequently,  the  power  P  is 
to  the  weight  W  as  the  velocity  of  the 
weight  to  ~the  velocity  of  the  power. 
Therefore  in  this,  as  in  all  mechanical  en- 
gines, when  a  small  power  raises  a  great 
weight,  the  velocity  of  the  power  is  much 
greater  than  the  velocity  of  the  weight ; 
and  what  is  gained  in  force  is  therefore 
said  to  be  lost  in  time. 

When  the  power  and  the  weight  do  not 
act  on  the  lever  in  directions  perpendicu- 
lar to  its  length,  or  when  the  arms  of  the 


310 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[lif 


lever  are  not  in  the  same  straight  line,  or 
are  bent,  then  the  power  and  the  weight 
are  not  to  each  other  reciprocally  as  the 
arms  of  the  lever,  but  as  the  straight  lines 
drawn  from  the  fulcrum  perpendicular  to 
the  respective  directions  in  which  the 
power  and  the  weight  take  effect. 

LICHENS  ;  a  family  of  plants,  belong- 
ing to  the  class  cryptogamia,  containing 
about  1400  known  species,  are  under  sev- 
eral genera.  Their  substance  is  powdery, 
crustaceous,  membranous,  coriaceous,  or 
even  corneous.  They  are  common  every 
where,  adhering  to  rocks,  the  trunks  of 
trees,  and  barren  soil.  On  .ascending 
mountains,  they  are  found  flourishing  be- 
yond the  limit  of  all  other  plants,  even  to 
the  verge  of  perpetual  snow.  Many  of 
them,  fixing  upon  the  hardest  rocks,  by 
retaining  moisture,  facilitate  their  decom- 
position and  promote  the  formation  of 
soil.  Several  of  the  species  are  used  for 
sustenance  in  times  of  scarcity,  by  the  in- 
habitants of  the  northern  regions. 

Iceland  moss  is  exceedingly  abundant 
in  the  arctic  regions,  and  often  affords 
aliment  to  the  inhabitants,  either  in  the 
form  of  gruel  or  bread,  which  last  is  very 
nutritious.  The  taste  is  bitter,  astringent, 
and  extremely  mucilaginous.  It  is  fre- 
quently employed  in  pharmacy,  in  the 
composition  of  various  pectoral  lozenges 
and  syrups,  and  is  celebrated  as  an  arti- 
cle of  diet,  in  combination  with  milk,  in 
coughs  and  pulmonary  affections. 

Orchil  {rocella  tinctoHa)  is  also  an  im- 
portant article,  though  less  used  now  than 
formerly,  on  account  of  the  fugitiveness 
of  the  rich  purple  and  rose-colored  dyes 
which  it  yields.  Some  of  its  tints,  how- 
ever, are  capable  of  being  fixed,  and  it  is, 
besides,  employed  for  staining  marble, 
forming  blue  veins  and  spots.  Several 
other  lichens  afford  dyes  of  various  colors, 
as  litmus. 

Lichen,  Liverwort,  or  Algse,  are  the 
stunted  herbage  of  the  arctic  circle,  and 
of  barren  heaths.  In  Iceland  and  Lap- 
land, it  is  eaten  in  broth  and  milk,  and 
even  made  into  bread,  its  bitterness  be- 
ing removed  by  washing  in  hot  waters. 
It  contains  much  mucilage  or  gluten,  and 
has  been  extensively  used  in  pulmonary 
complaints,  and  as  a  demulcent,  relieving 
cough,  and  correcting  all  acrid  secretions. 

Lichen,  Orchil,  or  Argol,  alluded  to 
above,  is  famous  for  its  dye  of  purple,  blue, 
violet,  &c.  It  is  mostly  brought  from  the 
Canary  Isles,  and  is  there  ground  in  a  mill, 
mixed  with  pearl-ash  and  urine,  and  sold 
in  cakes.  It  is  used  to  heighten  colors, 
but  is  very  evanescent,  except  when  used 


with  a  tin  solution,  which  gives  to  it  a  per- 
manent red  dve. 

LICK,  or  SALTLICK.  A  salt  spring 
is  called  a  lick  in  the  Western  States,  from 
the^  circumstance  that  the  earth  about  it, 
which  is  impregnated  with  saline  parti- 
cles, is  licked  by  the  bison  and  the  deer. 
Many  of  these  licks  appear  to  have  exist- 
ed before  the  habitation  of  the  earth  by 
man,  as  the  bones  of  the  mastodon  and 
other  fossil  animals  are  found  abundantly 
in  them.  They  appear  to  be  situated  in 
the  upper  secondary  beds,  and  contain 
both  iodine  and  bromine  in  combination 
dissolved  in  the  water.  The  latter  sub- 
stance is  in  such  marked  quantity  as  to 
make  these  springs  the  source  of  the  bro- 
mine manufacture. 

LIFE-BOAT.  A  boat  originally  made 
at  Shields,  in  1789,  by  Mr.  Greathead,  for 
saving  the  crews  of  shipwrecked  vessels. 
The  following  are  the  general  principles  : 
The  boat  is  wide  and  shallow ;  the  head 
and  stern  are  alike,  for  pulling  in  either 
direction,  and  raised,  to  meet  the  waves  ; 
it  pulls  double-banked,  the  oars  being  fir, 
for  lightness,  and  fitted  with  thole  pins 
and  grummets,  and  is  steered  with  an 
oar.  The  boat  is  cased  round  inside,  on 
the  upper  part,  with  cork,  in  order  to  se- 
cure her  buoyancy  with  as  many  persons 
as  she  can  carry,  even  though  full  of  wa- 
ter; the  cork  likewise  assists  in  main- 
taining, or,  if  overset,  in  recovering,  the 
position  of  stable  equilibrium.  The  boat 
is  painted  white,  to  be  conspicuous  in 
emerging  from  the  hollow  of  the  sea.  It 
is  a  curious  fact  that  the  smugglers  paint 
their  boats  white  for  the  contrary  reason, 
because  dark-colored  objects  alone  are 
discernible  in  dark  nights. 

If  a  spheroid  be  divided  into  quarters, 
each  quarter  is  elliptical,  and  resembles 
the  half  of  a  wooden  bowl,  having  a  cur- 
vature with  -projecting  ends.  Such  a  ves- 
sel thrown  into  the  sea  cannot  be  upset, 
or  lie  with  the  bottom  upwards,  owing  to 
the  ends.  The  length  is  30  feet,  the 
breadth  10  feet ;  the  depth  from  the  top 
of  the  gunwale  to  the  lower  part  of  the 
keel  in  midships,  3  feet  3  inches  ;  from 
the  gunwale  to  the  platform  (within),  2 
feet  4  inches ;  from  the  top  of  the  stems 
(both  ends  being  similar)  to  the  horizon- 
tal line  of  the  bottom  of  the  keel,  5  feet  9 
inches.  The  keel  is  a  plank  of  3  inches 
thick,  of  a  proportionate  breadth  in  mid- 
ships, narrowing  gradually  towards  the 
ends,  to  the  breadth  of  the  stems  at  the 
bottom,  and  forming  a  great  convexity 
downwards.  The  stems  are  segments  of 
a  circle,  with  a  considerable  rake.    The 


lif] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


311 


bottom  section,  to  the  floor-heads,  is  a 
curve  fore  and  aft.  with  the  sweep  of  the 
keel.  The  floor- timber  has  a  small  rise, 
curving  from  the  keel  to  the  floor-heads. 
A  bilge-plank  is  wrought-in  on  each  side, 
next  the  floor-heads,  with  a  double-rab- 
bet groove,  of  a  similar  thickness  with 
the  keel ;  and,  on  the  outside  of  this,  are 
fixed  two  bilge-trees,  corresponding  near- 
ly with  the  level  of  the  keel.  The  ends 
of  the  bottom  section  form  that  fine  kind 
of  entrance  observable  in  the  lower  part 
of  the  bow  of  the  fishing-boat,  called  a 
cobble,  much  used  in  the  north.  From 
this  part  to  the  top  of  the  stem  it  is  more 
elliptical,  forming  a  considerable  projec- 
tion. The  sides,  from  the  floor-heads  to 
the  top  of  the  gunwale,  flaunch  off  on 
each  side  in  proportion  to  above  half  the 
breadth  of  the  floor.  The  breadth  is  con- 
tinued far  forwards  towards  the  ends, 
leaving  a  sufficient  length  of  straight  side 
at  the  top.  The  sheer  is  regular  along 
the  straight  side,  and  more  elevated  to- 
wards the  ends.  The  gunwale  fixed  to 
the  outside  is  three  inches  thick. 

The  sides,  from  the  under  part  of  the 
gunwale,  along  the  whole  length  of  the 
regular  sheer,  extending  21  feet  6  inches, 
are  cased  with  layers  of  cork,  to  the 
depth  of  16  inches  downwards  :  and  the 
thickness  of  this  casing  of  cork  being  4 
inches,  it  projects  at  the  top  a  little  with- 
out the  gunwale.  The  cork,  on  the  out- 
side, is  secured  with  thin  plates  or  slips 
of  copper,  and  the  boat  is  fastened  with 
copper  nails.  The  thwarts,  or  seats,  are 
five  in  number,  double-banked;  conse- 
quently, the  boat  may  be  rowed  with  10 
oars.  The  thwarts  are  firmly  stanchion- 
ed. The  side-oars  are  short,  with  iron 
tholes  and  rope  grummets,  so  that  the 
rower  can  pull  either  way.  The  boat  is 
steered  with  an  oar  at  each  end ;  and  the 
steering-oar  is  one-third  longer  than  the 
rowing-oar.  The  platform  placed  at  the 
bottom,  within  the  boat,  is  horizontal,  the 
length  of  the  midships,  and  elevated  at 
the  ends,  for  the  convenience  of  the 
steersman,  to  give  him  a  greater  power 
with  the  oar.  The  internal  part  of  the 
boat  next  the  sides,  from  the  under  part 
of  the  thwarts  down  to  the  platform,  is 
cased  with  cork ;  the  whole  quantity  of 
which,  affixed  to  the  life-boat,  is  nearly 
seven  cwt.  The  cork  contributes  much 
to  the  buoyancy  of  the  boat,  and  is  a  good 
defence  in  going  alongside  a  vessel,  and 
is  of  use  in  keeping  the  boat  in  an  erect 
position  in  the  sea,  or  rather  for  giving  a 
very  lively  and  quick  disposition  to  reco- 
ver from  any  sudden  cant  or  lurch,  which 


she  may  receive  from  the  stroke  of  a 
heavy  wave. 

The  boats,  in  general,  of  this  descrip- 
tion, are  painted  white  on  the  outside: 
this  color  being  more  conspicuoos  when 
rising  from  a  hollow  of  the  sea.  The  bot- 
tom of  the  boat  is  varnished.  The  oars 
arc  made  of  flr,  of  the  best  quality.  In 
the  management,  she  requires  twelve 
men  to  work  her,  that  is,  five  on  each 
side,  rowing  double-banked,  with  an  oar 
slung  over  an  iron  thole,  with  a  grummet, 
so  as  to  enable  the  rower  to  pull  either 
way,  and  one  man  at  each  end  to  steer 
her,  and  to  be  ready  at  the  opposite  end 
to  take  the  steer-oar,  when  wanted.  The 
best  method,  if  the  direction  will  admit 
of  it,  is  to  head  the  sea.  Tlie  steersman 
should  keep  his  eye  fixed  upon  the  wave 
or  breaker,  and  encourage  the  rowers  not 
to  give  way,  as  the  boat  rises  to  it ;  being 
then  aided  by  the  force  of  the  oars,  she 
launches  over  it  with  vast  rapidity,  with- 
out shipping  any  water.  When  a  wreck 
is  reached,  if  the  wind  blows  to  the  land, 
the  boat  will  come  in  shore,  without  any 
other  effort  than  steering. 

Scheerboom  &  Co.  have  recently  in- 
vented an  apparatus  for  converting  any 
boat  or  vessel  into  a  life- boat,  in  cases  of 
danger,  and  it  is  recommended  by  high 
authorities. 

Mr.  Holbrook,  of  Hull,  England,  con- 
structed a  life-boat,  the  hull  of  which  is 
broad,  and  the  framework  composed  of 
wrought  iron  covered  with  net.  The 
body  is  divided  into  six  compartments, 
containing  bundles  of  floaters,  perfectly 
air-tight,  and  separate  from  each  other  s'o 
that  injury  to  one  will  not  affect  the  rest. 
The  peculiarity  of  the  boat  is,  it  has  no 
bottom  except  a  slight  framework  of  cor- 
dage or  netting,  the  object  of  the  arrange- 
ment being  to  allow  the  water  to  rise 
within  the  boat  to  the  level  of  that  with- 
out, and  so  secure  a  permanent  ballast  of 
water  which  precludes  the  possibility  of 
being  capsized  in  a  heavy  sea.  Thus  the 
countervailing  properties  of  buoyancy 
and  steadiness  are  perfectly  secured. 
The  internal  arrangements  include  means 
for  carrying  water,  spirits,  matches,  wood, 
articles  of  wearing  apparel,  with  appara- 
tus for  boiling  coffee  and  broiling  meat. 
The  boat  also  carries  a  reflecting  lamp, 
fire  balls,  blue  lights,  rockets,  300  feet  of 
line,  a  horn,  and  alarm  bell,  and  is  steered 
by  means  of  an  oar.  This  boat  has  been 
satisfactorily  tested  in  severe  weather. 

LIFE-BUOYS  consist  of  two  hollow 
copper  cylinders,  each  as  large  as  a  pillow, 
and  sufficient  to  support  one  man  stand- 


312 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[' 


ing  on  them  :  they  are  connected  to  each 
other.  Should  more  than  one  person  re- 
quire support,  they  can  lay  hold  of  rope 
beckets  fitted  to  the  buoy,  and  so  sustain 
themselves.  Between  the  two  copper 
vessels,  there  stands  a  hollow  pole,  or 
mast,  into  which  is  inserted,  from  below, 
an  iron  rod,  whose  lower  extremity  is 
loaded  with  lead,  in  such  a  manner  that, 
when  the  buoy  is  let  go,  the  iron  sl?ps 
down  to  a  certain  extent,  lengthens  the 
lever,  and  enables  the  lead  at  the  end  to 
act  as  ballast.  By  this  means  the  mast  is 
kept  upright,  and  the  buoy  prevented 
from  upsetting.  The  weight  at  the  end 
of  the  rod  is  arranged  so  as  to  afford  se- 
cure footing  for  two  persons,  should  that 
number  reach  it ;  and  there  are,  also, 
large  rope  beckets  through  which  they 
can  thrust  their  heads  and  shoulders,  till 
assistance  is  rendered.  At  the  top  of  the 
mast  is  fixed  a  port-fire  calculated  to  burn 
about  twenty  minutes  or  half  an  hour  ; 
this  is  ignited  most  ingeniously  by  the 
same  process  which  lets  the  buoy  fail  into 
the  water  ;  so  that  a  man  falling  over- 
board at  night  is  directed  to  the  tiuoy  by 
the  blaze  on  the  top  of  the  mast.  'The 
person  who  has  charge  on  board  ship  of 
the  life-buoy  sees  it  freshly  primed  every 
evening.  In  the  morning  the  priming  is 
taken  out  and  the  lock  uncorked. 

LIFE-PRESERVERS.  Apparatus  used 
at  sea  in  case  of  persons  falling  over- 
board. Mr.  Scheffer,  of  England,  in- 
vented a  cylindrical  tubular  ring  without 
seam  or  break  ;  it  contains  a  stop  cock 
and  ivory  pipe  affixed  ;  by  this  air  can 
be  blown  in  by  the  mouth  and  retained 
by  the  stop  cock.  When  not  inflated  it 
folds  up  into  a  very  small  compass,  suita- 
ble for  the  pocket,  and  weighs  only  twelve 
ounces. 

An  American  invention  of  a  similar 
character  in  the  form  of  a  straight  cylin- 
der of  a  caoutchouc  water-proof  material. 
The  simplest  form  is  a  rinsr  of  caoutchouc 
to  go  round  the  body  under  the  arm-pits, 
previously  blown  up  with  air. 

LIGNIN.  The  woody  fibre.  This 
most  important  proximate  principle  of 
vegetables  exhibits  itself  in  a  variety  of 
forms,  constituting  the  different  textures 
of  hard  and  soft  wood :  and  various 
fibrous  products,  such  as  hemp,  flax, 
cotton,  <fec.  When  by  fine  mechanical 
division  it  is  reduced  to  a  pulpy  state,  it 
is  formed  into  paper.  When,  by  differ- 
ent reagents,  all  the  soluble  matters  are 
extracted  from  wood,  the  insoluble  resi- 
due is  lignin  :  its  ultimate  components 
are  oharcoal,  oxygen,  and  hydrogen,  the 


latter  elements  being  in  the  same  ratio  as 
in  water  ;  so  that  wood  may  be  consid- 
ered as  a  compound  of  carbon  and  water, 
and  according  to  Dr.  Prout's  experiments, 
allaost  exactly  in  equal  weights.  Lignin 
is  very  imperishable  ;  but  under  certain 
circumstances  it  is  attacked  by  dry  rot, 
arising  out  of  the  growth  of  a  parasitic 
fungus,  which  causes  its  rapid  decay. 
Damp  timber,  in  situations  where  air  has 
not  free  access,  is  particularly  subject  to 
its  attacks  ;  arid  when  once  it  has  made 
its  appearance,  the  well-seasoned  timber 
in  its  neighborhood  becomes  liable  to  the 
same  disease.  The  dry  rot  may  be  pre 
vented  by  impregnating  the  timber  with 
certain  saline  solutions,  and  of  these  a 
solution  of  corrosive  sublimate  has  been 
found  most  effectual :  the  chloride  com- 
bines chemically  with  the  lignin,  and  the 
compound  is  very  indestructible.  See 
Kyanizino.  Lignin  has  also  a  strong  afc- 
traction  for  alumine  ;  and  hence  linen, 
cotton,  paper,  and  other  forms  of  this 
fibre,  may  be  aluminized  by  steeping  them 
in  hydrated  alumine,  diffused  through 
water  ;  or,  more  effectively  by  soaking 
them  in  certain  aluminous  solutions,  dry- 
ing them,  and  afterwards  washing  out 
the  excess  of  the  salt.  It  is  in  this  way 
that  cotton  goods  are  impregnated  with 
alumine  for  the  purpose  of  dyeing  and 
calico  printing.  Other  metallic  oxides 
exhibit  similar  attractive  powers,  espe- 
cially the  oxide  of  iron. 

The  analogy  that  exists  between  the 
composition  of  sugar,  gum,  starch,  and 
even  vinegar  and  lignin,  suggests  the 
possibility  of  the  conversion  of  those 
proximate  elements  into  each  other  ;  and 
it  has  accordingly  been  found  that  by 
carefully  roasting  pure  and  fine  sawdust, 
it  is  rendered  partially  soluble  in  water, 
and  that  a  part  of  it  is  converted  into  a 
nutritious  substance,  probably  intermedi- 
ate between  sugar  and  starch  ;  and  which 
when  mixed  with  a  little  flour,  yields  a 
palatable  bread,  not  very  unlike  that  made 
by  some  of  the  inhabitants  of  the  north- 
ern parts  of  Europe  of  the  bark  of  trees. 
Mixed  with  sulphuric  acid,  lignin  passes 
into  gum  ;  and  from  this  sugar  may  be 
obtained  by  boiling  it  for  some  hours  in 
a  very  dilute  sulphuric  acid;  this  sugar, 
when  purified,  much  resembles  grape  or 
honey  sugar.  By  this  process  rags  may 
be  converted  into" nearly  their  own  weight 
of  this  peculiar  saccharine  matter. 

The  production  of  vinegar  by  the  de- 
structive distillation  of  wood  was  origi- 
nally suggested  about  the  middle  of  the 
17th  century,  by  Glauber,  a  celebrated 


lig] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


313 


German  chemist  of  that  time  ;  it  has 
lately  become  a  very  important  branch  of 
manufacture  in  this  country.  Upon  the 
whole,  there  are  very  few  natural  pro- 
ducts equally  important  with  lignin  in 
their  applications  to  the  useful  and  orna- 
mental arts. 

LIGNITE.  Wood  converted  into  a 
kind  of  coal,  by  being1  placed  under 
ground  in  a  damp  situation. 

LIGHT.  The  philosophical  consider- 
ation of  this  imponderable  element,  as  it 
used  to  be  termed,  but  more  properly 
now  an  affection  of  the  ether  pervading 
all  space,  does  not  belong  to  a  treatise  on 
the  Useful  Arts.  The  practical  applica- 
tions and  various  kinds  of  artificial  fights 
are  those  points  only  which  can  be  touch- 
ed on.  Under  the  articles  Candle,  Gas, 
and  Lamps,  the  subject  of  artificial  light 
has  been  alluded  to.  It  is  proper  here 
to  note  a  few  other  forms :  of  these  the 
Drummond  Light  stands  foremost.  This 
light  arises  from  exposing  a  globule  or 
pea  of  lime  to  ignition  in  a  blow-pipe, 
consuming  oxygen  and  hydrogen.  It 
resembles  the  focus  of  a  reflector  in  the 
sun,  and  has  already  been  applied  to  the 
microscope  as  a  substitute  lor  the  sun, 
and  by  Lieut.  Drummond  to  the  illumi- 
nation of  light-houses,  instead  of  Argand 
burners.  The  ignition  lasts  from  15  to 
25  minutes,  when  new  globules  are  in- 
serted. From  a  small  ball,  only  three- 
eighths  of  an  inch  in  diameter,  so  bril- 
liant a  light  is  emitted  that  it  equals  in 
quantity  about  13  Argand  lamps,  or  120 
wax-candles  ;  while,  in  intensity  or  in- 
trinsic brightness,  it  is  260  times  that  of 
an  Argand  lamp.  Some  idea  of  its  in- 
tense light  may  be  gained  from  the  fact 
that  when  the  Ordnance  Survey  of  Ire- 
land was  being  made,  it  was  necessary 
to  have  a  fixed  point  of  observation, 
which  might  be  seen  at  some  distance. 
This  light  was  usually  placed  on  a  hill, 
and  with  the  telescope  its  light  in  the 
day  time  was  discernible  30  miles  off. 
In  revolving  lights,  such  as  that  of  Beachy 
Head,  England,  there  are  no  less  than  30 
reflectors,  10  on  each  side.  A  single  re- 
flector, therefore,  illuminated  by  a  lime- 
ball,  for  each  of  these  10  is  26  times 
greater  than  that  of  the  30.  This  method 
was  tried  lately  at  Purfleet,  off  the  En- 
glish coast,  in  a  temporary  light-house, 
erected  for  the  purpose  of  experiments 
by  the  Corporation  of  the  Trinity-house, 
and  its  superiority  over  all  the  other 
lights  with  which  it  was  contrasted  was 
fully  ascertained  and  acknowledged.  On 
an  evening,  when  there  was  no  moon- 
14 


light,  and  the  night  dark,  with  occa- 
sional showers,  tlie  appearance  of  the 
Purfleet  light,  viewed  from  Blackwall,  a 
distance  of  10  miles,  was  very  splendid. 
Distinct  shadows  were  discernible,  even 
on  a  dark  brick-wall,  though  no  trace  of 
such  shadows  could  be  perceived  when 
the  other  lights,  consisting  of  seven  re- 
flectors, with  Argand  lamps,  and  French 
lenses,  were  directed  on  the  same  spot. 
Another  striking  and  beautiful  effect, 
peculiar  to  this  light,  was  discernible 
when  the  reflector  was  turned,  so  as  to 
be  itself  invisible  to  the  spectator ;  a 
long  stream  of  rays  was  seen  issuing 
from  the  spot  where  the  light  was  placed, 
which  illuminated  the  horizon  to  a  great 
distance.  As  the  reflector  revolved,  this 
immense  luminous  cone  swept  the  hori- 
zon, and  indicated  the  approach  of  the 
light,  long  before  it  could  itself  be  seen 
from  the  position  of  the  reflector. 

The  same  balls  have  been  substituted 
for  sunshine,  by  Carey,  of  London,  in 
very  powerful  microscopes,  and  are  con- 
stantly on  exhibition  in  museums.  The 
Drummond  Light  is  well  adapted  for  the 
Magic  Lantern  illustrations. 

Gillard  Light.  —  M.  J.  P.  Gillard,  a 
French  gentleman,  has  taken  out  a  pa- 
tent in  England,  in  1849,  for  improve- 
ments in  the  production  of  heat  and  light 
in  general. 

The  patentee's  invention  consists  in 
certain  apparatus  and  processes  for  pro- 
ducing hydrogen  gas,  by  the  decompo- 
sition of  water,  and  its  application  to 
heat  and  light.  The  means  and  pro- 
cesses by  which  he  obtains  this  gas  are : 
1.  By  the  incandescency  of  iron.  2.  By 
carbon.     3.  By  magnesia. 

His  improved  process  for  rendering 
hydrogen  gas  illuminating,  is  by  causing 
a  small  jet  of  lighted  hydrogen  to  pass 
through  a  burner  (the  holes  very  small) 
on  a  thin  strip  of  platinum  wire,  the 
threads  being  excessively  fine,  and  of 
graduated  section,  proportioned  to  in- 
tensity of  the  pressure  of  the  flame  and 
the  burning  hydrogen, — a  very  powerful 
light  is  thus  produced.  The  platinum 
threads  are  immediately  heated  to  such 
whiteness  that  the  luminous  refulgence 
is  extraordinarily  brilliant.  Besides  pla- 
tinum, other  unalterable  and  unoxidizable 
metals  may  be  employed.  The  wick 
must  be  of  the  shape  necessary  to  agree 
with  that  of  the  jet  of  hydrogen, — it  may 
be  that  of  a  cone,  or  any  other  figure, 
according  to  the  size  which  the  gas  takes 
when  it  is  allowed  egress  from  the  burn- 
er ;  the  wick  must  be  made  more  or  less 


314 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lim 


strong,  according  to  the  greater  or  less 
intensity  of  the  heat  to  which  it  is  ex- 
posed. The  burner  and  wick  may  be 
modified  in  their  shape, — the  patentee 
does  not  limit  himself  as  regards  the 
strength,  the  length,  or  the  height  of  the 
wick,  provided  the  principle  of  his  in- 
vention be  retained. 

The  invention  of  M.  Gillard  has  been 
introduced  into  Manchester  by  Mr.  Kurz, 
whose  chemical  works  are  at  Cornbrook, 
Hulme,  England. 

The  following  is  a  plan  adopted  in  the 
new  process  : — An  inch  pipe  is  connect- 
ed with  the  steam-boiler  used  in  the 
general  manufacturing  process  carried 
on  at  the  works  ;  and  thence  runs  back 
to  the  retort  furnace,  passing  underneath 
the  fire  bars,  and  passing  up  the  front 
of  the  furnace,  to  the  level  of  the  bottom 
of  a  common  I)  retort,  about  a  foot  inter- 
nal diameter.  A  £  inch  pipe  is  then 
carried  the  whole  length  of  the  interior 
of  the  retort ;  the  underside  of  the  pipe 
is  perforated  with  three  rows  of  fine  and 
closely-arranged  holes,  those  of  the  cen- 
tre row  being  perpendicular,  and  the 
others  slanting  outwards.  The  retort 
having  been  brought  to  a  white  heat,  its 
bottom  being  covered  with  broken  char- 
coal, the  steam  being  admitted,  the  gas 
is  freely  produced,  from  the  retort,  the 
water  gas  is  passed  along  through  ordi- 
nary purifiers  (the  same  in  fact  that  have 
been  long  used  at  the  works),  and  the 
effects  are,  that  the  water  remains  per- 
fectly sweet  and  clear,  but  slightly  car- 
bonated, and  the  lime  is  converted  into 
chalk.  The  gas  is  not  yet  generally  used 
in  Mr.  Kurtz's  works ;  but  in  a  cellar 
about  26  yards  long  and  eight  or  ten 
broad,  three  ordinary  argand  burners 
(with  an  addition,  to  whiclT  we  shall  re- 
fer) give  considerably  more  light,  of  a 
more  pleasing  character,  than  would  or- 
dinarily be  required  in  such  a  place  for 
mercantile  purposes,  or  would  be  pro- 
duced by  a  dozen  batswing  lights  with 
ordinary  gas.  A  newspaper  could  be 
read  with  ease,  at  a  distance  of  40  ft.  to 
45  ft.  by  the  light  from  a  single  burner, 
with  a  reflector.  The  fact  of  the  possi- 
bility of  producing  a  gas  from  a  decom- 
position of  water  has  been  known  to  sci- 
entific men  for  50  or  60  years ;  the  ques- 
tion has  been,  how  to  render  it  available 
for  the  purposes  of  illumination.  M. 
Gillard's  invention,  for  this  purpose, 
consists  of  a  small  circular  cage  of  very 
fine  platina  wire,  worked  in  a  similar 
manner  to  the  material  for  a  fancy  basket. 
This  cage  of  wire  is  attached  to  a  small 


brass  frame,  fitting  on  to  the  burner,  so 
that  the  lower  edge  of  the  cage  is  brought 
immediately  over,  and  at  a  small  distance 
from  the  perforations  in  the  burner. 
Without  the  wire-work,  the  gas  burns 
similar  to  a  large  spirit-lamp,  emitting  a 
great  heat,  but  perfectly  useless  as  a 
means  of  illumination.  But  instantly  on 
the  addition  being  made,  the  flame  appa- 
rently changes  into  a  column  of  intensely 
white  light  over  the  whole  surface  of  the 
wire-work,  with  a  slight  appearance  of 
an  inner  flame  rising  rather  above  it. 
The  latter,  however,  disappears  when  a 
glass  is  added,  and  there  is  then  not  a 
particle  of  smell  or  smoke  emitted.  One 
burner  in  the  counting-house  has  been 
found,  by  a  rough  calculation,  to  con- 
sume from  7i  to  8i  cubic  feet  of  gas  per 
hour ;  and  with  the  consumption  a  pho- 
tometer shows  that  its  light  is  about  12 
times  as  powerful  as  that  given  by  one 
of  the  largest  kind  of  composite  candles. 
With  regard  to  the  injury  to  the  platina 
wire-frame,  M.  Gillard  states  that  there 
are  some  at  Paris  which  have  been  al- 
most continually  used  for  five  years, 
without  having  suffered  in  the  slightest 
degree  ;  and  his  conviction  is,  that  with 
pure  water  gas,  the  wire  would  remain 
uninjured  for  an  indefinite  period.  If 
one  of  the  platina  frames  be  placed  over 
a  common  gas  light,  it  is  very  soon  de- 
stroyed ;  the  frames  used  are  about  li 
in.  deep  and  f  in.  m  diameter.  The  heat 
thrown  out  by  the  gas  is  very  great,  but 
it  is  wholly  devoid  of  smoke  or  smell ; 
and  on  the  hand  being  held  over  one  of 
the  flames,  the  sensation  is  rather  that 
produced  by  steam,  or  hot  vapor,  than 
the  dry,  scorching  feeling,  caused  by 
common  gas.  An  experiment  has  been 
tried,  of  burning  a  large  jet  inside  a 
shade  on  the  hearth-stone,  and  the  heat 
diffused  was  most  pleasant  and  genial, 
the  effect  being  felt  in  every  part  of  the 
room  almost  instantly  on  the  gas  being 
lighted.  A  large  pan  of  water  was  made 
to  boil  by  the  flame  from  this  burner  in 
a  minute  and  a  half;  and  an  intention 
has  been  mentioned  of  attaching  to  the 
pipe  a  flexible  tube,  and  by  this  means 
boiling  water  on  the  breakfast,  tea,  or 
supper  table.  It  is  intended  by  Mr. 
Kurtz  to  have  the  whole  of  his  house 
warmed  by  the  gas,  and  stoves  fitted  up 
for  all  culinary  purposes ;  M.  Gillard 
stating,  positively,  as  the  result  of  ex- 
periments, that  lie  can  by  means  of  his 
gas  roast  a  fowl  in  five  minutes,  or  a  leg 
of  mutton  in  fifteen  minutes. 
LIME.    The  oxide  of  calcium,  one  of 


lim] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


315 


the  metals  of  the  earths.  This  very  use- 
ful earth  is  obtained  by  exposing  chalk 
and  other  kinds  of  limestone,  or  carbon- 
ates of  lime,  to  a  red  heat — an  operation 
generally  conducted  in  kilns  constructed 
for  the  purpose  ;  the  carbonic  acid  is  thus 
expelled,  and  lime,  more  or  less  pure, 
according  to  the  original  quality  of  the 
limestone,  remains.  In  this  state  it  is 
usually  called  quicklime.  When  sprinkled 
with  water  it  becomes  very  hot,  and 
crumbles  down  into  a  dry  powder,  called 
elated  lime,  or  hydrate  of  lime.  When 
exposed  for  some  weeks  to  the  air  it  also 
falls  into  powder,  in  consequence  of  the 
absorption  of  moisture,  and  of  a  portion 
of  carbonic  acid ;  so  that,  in  this  case, 
part  of  the  lime  gradually  reverts  to  the 
state  of  carbonate,  and  loses  its  causticity. 
Pure  lime  may  be  obtained  by  heating 
powdered  Carrara  marble  to  whiteness  in 
an  open  crucible.  It  is  white,  very  fusible, 
highly  luminous  when  heated  to  full  red- 
ness, and  of  a  specific  gravity  of  about 
2-3.  It  requires  for  solution  about  500 
parts  of  water,  and  is  somewhat  more 
soluble  in  cold  than  in  hot  water.  But, 
weak  as  this  solution  is,  it  acts  powerfully 
alkaline  upon  vegetable  colors,  and  has 
an  acrid  taste ;  hence  the  term  alkaline 
earth  applied  to  lime.  It  absorbs  car- 
bonic acid  by  exposure  to  air,  and  as  car- 
bonate of  lime  is  insoluble  in  water,  it  be- 
comes milky  in  consequence ;  so  that, 
from  this  property,  lime-water  is  a  useful 
test  of  the  presence  of  carbonic  acid. 
The  nature  of  lime  was  first  demonstrated 
by  Davy  in  1807 :  he  showed  that,  like 
the  other  alkalies,  it  was  a  metallic  oxide. 
The  metallic  base  of  lime  has  been  termed 
calcium:  its  equivalent  is  20,  and  lime, 
being  a  compound  of  one  atom  of  calcium, 
and  one  of  oxygen,  is  represented  by  the 
equivalent  number  28;  and  hydrate  of 
lime  by  28  lime  -f-  9  water  =  37.  The 
salts  of  lime  are  generally  obtained  by 
dissolving  carbonate  of  lime  in  the  re- 
spective acids :  several  of  them  exist 
native.  Sulphate  of  lime,  selenite,  or 
gypsum,  is  an  abundant  natural  product, 
and  may  be  formed  artificially  by  adding 
sulphuric  acid,  or  the  soluble  sulphates, 
to  solutions  of  the  salts  of  lime.  It  con- 
sists of  28  lime  -f  40  sulphuric  acid,  and 
its  crystals  include  two  atoms  =18  of 
water.  When  these  crystallized  sul- 
phates of  lime  are  heated,  they  part  with 
their  water  and  fall  into  a  white  powder, 
called  plaster  of  Paris;  when  this  is 
mixed  with  water  it  again  combines  with 
it,  and  concretes  into    a   white    mass ; 


hence  its  use  for  casts,  busts,  &c.  Sul- 
phate of  lime  is  often  contained  in  spring 
water,  which  is  thus  rendered  hard  and 
unfit  for  washing.  These  waters  become 
turbid  upon  the  addition  of  a  spirituous 
solution  of  soap.  Phosphate  of  lime  is 
found  native,  constituting  the  mineral 
called  apatite :  this  is  a  subphosphate, 
composed  of  3  equivalents  of  lime  =84, 
and  2  of  phosphoric  acid  =  72.  The  earth 
of  bones  is  also  chiefly  a  similar  phos- 
phate of  lime.  Oxalate  of  lime  is  very 
insoluble,  and  is  precipitated  whenever 
oxalic  acid  or  a  solution  of  oxalate  is 
added  to  solutions  containing  lime ; 
hence  it  is  that  oxalate  of  ammonia  is  so 
valuable  a  test  of  the  presence  of  lime, 
and  is  frequently  used  for  the  purpose  of 
separating  lime  in  analysis.  When  oxa- 
late of  lime  is  well  dried,  at  500°,  it  is 
anhydrous,  and  consists  of  28  lime  +  36 
oxalic  acid  =64  oxalate  of  lime.  This 
substance  is  occasionally  found  in  the 
human  urine,  and  sometimes  forms  cal- 
culi. These  are  often  of  a  reddish  brown 
color  and  a  rough  exterior,  whence  they 
have  been  termed  mulberry  calculi. 
When  hydrate  of  lime  is  exposed  to 
chlorine,  the  gas  is  absorbed,  and  a  chlo- 
ride of  lime  is  obtained.  This  article  is 
manufactured  upon  an  extensive  scale, 
under  the  name  of  teaching  powder.  It 
evolves  chlorine  when  acted  upon  by 
acids  ;  and  gives  it  out  very  slowly  when 
exposed  to  air,  in  consequence,  probably, 
of  the  absorption  of  carbonic  acid.  It  is 
a  most  useful  disinfecting  material,  and, 
when  dissolved  in  water,  forms  bleaching 
liquid.  Carbonate  of  lime  is  thrown  down 
wlien  alkaline  carbonates  are  added  to 
solutions  of  the  salts  of  lime.  It  is  a 
most  abundant  natural  product,  and  is 
found  pure  in  the  varieties  of  calcareous 
spar  and  statuary  marble.  Chalk  and 
several  varieties  of  limestone  are  also 
nearly  pure  carbonates  of  lime.  It  is 
easily  distinguished  from  other  minerals 
by  effervescing  in  dilute  muriatic  acid, 
and  by  yielding  quicklime  when  a  frag- 
ment is  heated  before  the  blowpipe.  It 
is  constituted  of  28  lime  +  22  carbonic 
acid ;  the  equivalent,  therefore,  of  car- 
bonate of  lime  is  50. 

The  uses  of  lime  are  very  numerous. 
Its  most  important  application  is  in  the 
manufacture  of  mortar  and  other  cements 
used  in  building.  It  is  also  very  exten- 
sively used  in  this  country  as  a  manure 
to  fertilize  land.  But  it  is  a  curious  fact 
that  the  use  of  lime  as  a  manure  is  en- 
tirely a  European  practice,  its  employ 


316 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[lim 


ment  in  this  way  having  been  never  so 
much  as  dreamed  of  by  the  natives  of 
Asia  or  Africa. 

Native  preparations  of  lime. — 1.  Calc 
Spar,  in  colorless  crystals,  is  scratched 
by  the  nail.    Spec.  grav.  2*7. 

2.  Stalactitic,  or  concretionary  carbon- 
ate of  lime,  composed  of  fibrous  bands, 
undulated  and  parallel.  These  are  found 
in  caves  and  vaults,  being  formed  by  the 
dropping  of  water  highly  charged  with 
limestone  and  carbonic  acid.  That 
which  remains  on  the  roof  is  called  stal- 
actite, that  which  forms  on  the  ground  is 
called  stalagmite,  or  oriental  alabaster: 
its  rings  are  spread  out  of  a  reddish  yel- 
low color,  with  distinct  zones,  and  sus- 
ceptible of  a  fine  polish.  This  alabaster 
is  made  into  furniture  ornaments. 

3.  Calcareous  tufa  are  incrustations  of 
carbonate  of  lime  upon  vegetable  remains 
made  by  the    deposition  of  calcareous 

Eetrifying  rivulets.  It  is  porous,  cellu- 
ir,  soft,  impure,  and  of  a  dirty  gray 
color ;  it  is  rough  and  irregular.  The 
incrustations  are  occasionally  so  large, 
that  buildings  are  made  of  them.  The 
travertino  with  which  the  monuments 
of  Rome  are  made,  are  deposits  from 
the  Anio.    They  harden  in  the  air. 

4.  Compact  limestone  has  an  even 
grain;  does  not  polish  or  afford  large 
blocks — to  this  class  belongs  the  Mag- 
nesian  limestone,  or  zechstein,  in  which 
the  lithographic  limestone  is  included 
according  to  Brogniart. 

5.  Oolite  or  roe  stone,  found  in  small 
grains  of  various  size. 

6.  Chalk.  Neither  of  these  two  varie- 
ties exist  to  any  extent  on  this  continent. 

7.  Marly  limestone,  very  common  on 
clay  slate  lands,  and  in  basin-shaped 
lakes,  and  fresh  water  formations.  This 
crumbles  in  the  air :  it  must  not  be  con- 
founded with  common  marl. 

8.  Siliceous  limestone,  compact,  scrat- 
ches steel ;  leaves  insoluble  silica  when 
acted  on  by  hydrochloric  acid. 

9.  Calp,  fine  grained,  compact,  hard, 
blue-black  in  color;  leaves  silica  and 
alumina  when  acted  on  by  acid ;  found  in 
extensive  beds. 

10.  Bituminous  limestone,  found  near 
the  coal  formations ;  of  a  blue  color, 
burns  white. 

Of  all  common  limestones  the  purity 
may  be  most  readily  determined  by  the 
quantity  of  carbonic  acid  which  is  evolved 
during  their  solution  in  dilute  nitric  or 
muriatic  acid.  Perfect  carbonate  of  lime 
loses  in  this  way  46  per  cent. ;  and  if  any 
particular  limestone  loses  only  2Sper  cent., 


we  may  infer  that  it  contains  only  one 
half  its  weight  of  calcareous  carbonate. 
This  method  is  equally  applicable  to 
marls,  which  are  mixtures  in  various  pro- 
portions of  carbonate  of  lime,  clay,  and 
sand,  and  may  all  be  recognized  by  their 
effervescing  with  acids. 

The  chief  use  of  calcareous  stones  is 
for  procuring  quicklime  by  calcination  in 
proper  furnaces  ;  and  they  are  all  adapted 
to  this  purpose  provided  they  are  not 
mixed  with  too  large  a  proportion  of  sand 
and  ferruginous  clay,  whereby  they  ac- 
quire a  vitrescent  texture  in  a  high  heat, 
and  will  not  burn  into  lime.  Limestone 
used  to  be  calcined  in  a  very  rude  kiln, 
formed  by  inclosing  a  circular  space  of 
10  or  15  feet  diameter,  by  rude  stone 
walls  4  or  5  feet  high,  and  filling  the  cyl- 
indrical cavity  with  alternate  layers  of 
turf  or  coal  and  limestone  broken  into 
moderate  pieces.  A  bed  of  brushwood 
was  usually  placed  at  the  bottom,  to  facil- 
itate the  kindling  of  the  kiln.  Whenever 
the  combustion  was  fairly  commenced, 
the  top,  piled  into  a  conical  form,  was 
covered  in  with  sods,  to  render  the  calcin- 
ation slow  and  regular.  This  method  be- 
ing found  relatively  inconvenient  and  in- 
effectual, was  succeeded  by  a  permanent 
kiln  built  of  stones  or  brickwork,  in  the 
shape  of  a  truncated  cone  with  the  narrow 
end  undermost,  and  closed  at  bottom  by 
an  iron  grate.  Into  this  kiln,  the  fuel  and 
limestone  were  introduced  at  the  top  in 
alternate  layers,  beginning  of  course  with 
the  former ;  and  the  charge  was  either  al- 
lowed to  burn  out,  when  the  lime  was 
altogether  removed  at  a  door  near  the  bot- 
tom, or  the  kiln  was  successively  fed  with 
fresh  materials,  in  alternate  beds,  as  the 
former  supply  sunk  down  by  the  calcina- 
tion, while  the  thoroughly  burnt  lime  at 
the  bottom  was  successively  raked  out  by 
a  side  door  immediately  above  the  grate. 
The  interior  of  the  lime  kiln  has  been 
changed  of  late  years  from  the  conical  to 
the  elliptical  form  ;  and  probably  the  best 
is  that  of  an  egf:  placed  with  its  narrow 
end  undermost,  and  truncated  both  above 
and  below  ;  the  ground  plot  or  bottom  of 
the  kiln  being  compressed  so  as  to  give 
an  elliptical  section,  with  an  eye  or  draft- 
hole  towards  each  end  of  that  ellipse.  A 
kiln  thus  arched  in  above  gives  a  rcver- 
beratory  heat  to  the  upper  materials,  and 
also  favors  their  fulling  down  in  propor- 
tion as  the  finished  lime  is  raked  out  be- 
low; advantages  which  the  conical  form 
does  not  afford.  The  size  of  the  draft- 
notes  for  extracting  the  quicklime, 
should  be  proportionate  to  the  size  of  the 


lim] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


317 


kiln,  in  order  to  admit  a  sufficient  current 
of  air  to  ascend  with  the  smoke  and 
flame,  which  is  found  to  facilitate  the  ex- 
trication of  the  carbonic  acid.  The  kilns 
are  called  perpetual,  because  the  operation 
is  carried  on  continuously  as  long  as  the 
building  lasts ;  and  draw-kilns,  from  the 
mode  of  discharging  them  by  raking  out 
the  lime  into  carts  placed  against  the 
draft-holes.  Three  bushels  of  calcined 
limestone,  or  lime-shells,  are  produced  on 
an  average  for  every  bushel  of  coals  con- 
sumed. "Such  kilns  should  be  built  up 
against  the  face  of  a  cliff,  so  that  easy  ac- 
cess may  be  gained  to  the  mouth  for 
charging,  by  making  a  sloping  cart  road 
to  the  top  o"f  the  bank. 

Limestone  may  be  burned  in  the  field 
in  heaps,  with  coal,  where  it  is  quarried, 
or  where  the  lime  is  to  be  used,  30  bush- 
els of  coal  to  100  of  limestone  are  used, 
the  two  being  interstratified  for  burning. 
Flues  are  dug  in  the  ground,  and  the 
heaps  or  piles  may  be  made  of  any  desired 
size  :  their  bases  are  usually  10  to  15  feet 
wide,  and  are  carried  up  in  somewhat  of 
a  gothic  arch  shape,  to  a  point  or  ridge, 
so  as  to  make  the  height  about  the  same 
as  the  base.  The  quantity  of  coal  used  is 
in  the  proportion  of  about  one  ton  of  coal 
to  100  bushels  of  limestone — if  the  coal  is 
fine  and  slaty,  a  somewhat  larger  propor- 
tion is  used.  The  length  of  the  piles  is 
made  to  correspond  with  the  quantity  of 
lime  desired  at  one  time,  say  from  20  to 
100  feet  in  length.  The  ground  flues, 
which  are  about  12  or  18  inches  square, 
are  extended  to  about  3  feet  out  on  each 
side,  to  admit  the  wood  which  is  burned 
in  them  to  start  the  fire  and  ignite  the 
coal  in  the  heap,  which  usually  takes  4  to 
6  hours,  and  about  half  a  cord  dry  wood 
to  1000  bushels  of  coal.  After  the  pile  is 
constructed  it  is  plastered  over  to  within 
about  18  inches  of  the  top  on  each  Bide, 
with  wet  plaster  mortar  made  of  clay ; 
this  covering  is  from  3  to  5  inches  thick. 
About  H  feet  of  the  top  heap  is  construct- 
ed of  small  stones  or  stone  chips,  and  is 
left  uncovered  until  the  fire  is  fully  start- 
ed, then  covered  over  with  dry  dirt  to 
keep  down  a  too  rapid  combustion.  The 
clay  coat  is  put  on  before  firing,  and  is 
kept  plastered  over  close  during  the  burn- 
ing. The  outside  courses  of  stone  are  set 
on  edge  in  an  oblique  manner,  the  direc- 
tion of  their  inclination  being  changed 
each  course,  which  form  a  zigzag  appear- 
ance. The  outside  courses  are  laid  with 
earn,  taking  stone  of  about  the  same  size, 
but  the  interior,  after  the  first  2  or  3 
courses,  is  filled  up  with  stone  of  all  sizes, 


to  the  extent  of  30  pounds,  but  each  coat 
of  coarse  stone  is  tilled  up  and  levelled 
over  with  small  stone  of  more  uniform 
size — say  as  large  as  the  first,  and  then 
the  course  of  coal   is  strewn  o\er  the 
smaller  stones  before  another  course  is 
j  added.    The  first  three  courses  are  of 
I  about  a  uniform  size  of  half  a  brick,  and 
j  covered  with  a  larger  proportion  of  coal 
|  than  the  courses  higher  up,  the  depth  or 
!  thickness  of  which  is  progressively  in- 
creased to  15  or  18  inches  in  the  bociy  of 
the  piles.     As    the    courses    are    made 
thicker,  so  are  stone  used  of  larger  size — 
but  the  coarse  stone  are  to  be  levelled  up 
and  covered  with  smaller  stone  to  receive 
the  strata  of  coal. 

The  ground  flues  are  covered  with 
stone,  which  are  large  enough  to  reach 
across  and  lap  4  to  6  inches  on  each  side 
of  the  ditch,  or  the  stone  may  be  project- 
ed from  either  side  to  meet  in  the  middle 
of  the  flue — having  sufficient  bearing  on 
each  side  of  the  flue  or  ditch  to  keep 
them  from  tilting  into  the  flue  when 
laid.  Over  these  stone,  and  throughout 
the  whole  base  of  the  pile,  is  laid  a  cover- 
ing, say  3  or  4  inches  thick,  of  dry  wood, 
and  on  this  is  about  2  inches  in  depth  of 
mineral  coal  spread  over,  then  a  course 
of  limestone,  say  size  of  half  a  common 
brick.  Coal  and  limestone  are  thus  alter- 
nated for  two  or  three  courses,  then  the 
thickness  of  each  course  is  gradually  in- 
creased as  we  raise  in  height. 

In  some  places,  where  coal  is  scarce, 
wood  or  peat  is  used,  and  these  are  to  be 
placed  in  layers,  alternate  with  the  lime, 
in  a  conical  or  egg-shaped  form,  covered 
with  clay,  and  5  or  6  yards  in  diameter, 
with  a  funnel  of  dry  brushwood  down 
the  centre,  two  feet  wide.  The  pile  is 
fired  from  the  top  of  this  funnel,  which 
will  burn  down  to  the  bottom,  and  set  the 
whole  in  combustion. 

The  best  form  of  the  kiln  is  the  egg 
shape,  and  wood  is  preferred  to  coal  in 
the  burning.  A  lime-kiln  should  always 
be  built  high,  and  the  diameter  accord- 
ing to  the  height.  By  burning  chalk  in  a 
kiln,  good  lime  is  the  result.  After  lime- 
stone is  burned,  it  is  much  lighter  than 
before,  but  it  recovers  its  weight  in  a, 
great  measure  when  exposed  to  the  air, 
as  it  absorbs  carbonic  acid  therefrom. 
The  burning  of  lime  is  any  thing  but  an 
agreeable  or  healthy  business,  but  like 
many  others  it  is  very  useful  and  ne- 
cessary. 

There  is  one  thing  curious  about  lime- 
stone, viz.,  if  it  be  imperfectly  burned  in 
the  first  instance,  and  the  stone  cooled, 


318 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[lin 


no  subsequent  burning  will  make  it  into 
quicklime.  In  agriculture,  lime  is  a  great 
iertilizer,  by  hastening  the  decomposition 
of  vegetable  matter ;  and  as  all  marl  is  a 
species  of  lime,  it  would  be  the  better  for 
being  burned  before  it  is  used,  if  the  object 
of  adding  be  to  hasten  that  decomposition. 

Quicklime  is  employed  in  a  multitude 
of  preparations  subservient  to  the  arts  ; 
for  clarifying  the  juice  of  the  sugar-cane 
and  the  beet-root ;  for  purifying  coal  gas  ; 
for  rendering  the  potash  and  soda  of  com- 
merce caustic  in  the  soap  manufacture, 
and  in  the  bleaching  of  linen  and  cotton; 
for  purifying  animal  matters  before  dis- 
solving out  their  gelatine ;  for  clearing 
hides  of  their  hair  in  tanneries  ;  for  ex- 
tracting the  pure  volatile  alkali  from  mu- 
riate or  sulphate  of  ammonia  ;  for  ren- 
dering confined  portions  of  air  very  dry ; 
for  stopping  the  leakage  of  stone  reser- 
voirs, when  mixed  with  clay  and  thrown 
into  the  water  ;  for  making  a  powerful 
lute  with  white  of  eeg  or  serum  of  blood ; 
for  preparing  a  depilatory  pommade  with 
sulphuret  ot  arsenic,  &c.  Lime  water  is 
used  in  medicine,  and  quicklime  is  of 
general  use  in  chemical  researches.  Next 
to  agriculture  the  most  extensive  applica- 
tion of  quicklime  is  to  Mortar-Cements, 
which  see. 

In  the  employment  of  lime  in  agri- 
culture much  empiricism  has  been  used, 
and  ground  has  been  as  much  injured  as 
benefited  by  its  use.  The  majority  of 
cultivated  crops  require  lime,  and  it  is 
found  in  their  ashes  when  burned  :  hence 
if  the  soil  do  not  contain  lime  these  plants 
cannot  grow.  If  the  soil  be  deficient  in 
lime  or  only  present  in  small  quantity, 
lime  is  serviceable  ;  if  it  be  very  clayey 
lime  is  also  desired.  If  much  vegetable 
matter  be  present  lime  is  necessary  to 
make  it  pass  through  the  decompositions 
useful  for  plants  that  is  to  form  carbonic 
acid.  This  is  the  main  use  of  lime  :  if 
there  be  a  small  amount  of  organic  matter 
present,  lime  will  be  injurious  and  the 
ground  will  become  poorer  ;  the  addition 
of  lime  should  always  be  in  proportion 
Jo  the  quantity  of  organic  matter  present. 
Lime  is  more  used  in  England  than  on 
this  continent,  and  appears  to  be  more 
required,  it  contributing  to  warm  the  soil 
and  force  the  plant,  processes  performed 
by  a  less  obscured  sun  here.  Wheat 
scarcely  grows  well  on  English  land, 
which  does  not  contain  2i  per  cent,  of 
lime  as  carbonate,  while  some  of  the 
richest  land  of  the  Genesee  Valley  con- 
tains less  than  one-half  per  cent.  An 
ordinary  dressing  of  caustic  lime  varies 


from  30  to  100  bushels.  Marls  may  be 
laid  on  much  heavier. 

LIME,  Hyposulphite  of.  A  salt  now 
used  in  the  refining  of  sugar ;  it  may  be 
prepared  in  the  following  way : — Boil  to- 
gether an  excess  of  lime  and  sulphur 
with  water  in  any  convenient  vessel  un- 
til the  mixture  assumes  a  deep  red  color, 
and  then  allow  it  to  settle  for  some  time. 
The  clear  solution  contains  a  mixture  of 
hyposulphite  of  lime  and  sulphuret  of 
calcium.  To  this  clear  solution  sulphur- 
ous acid  gas  (vapors  of  burning  sulphur) 
is  to  be  added  until  the  red  color  disap- 
pears, and  no  further  deposit  will  take 
place,  when  considerable  sulphuric  acid  is 
added  when  in  a  cold  state.  The  solution  is 
then  filtered  and  the  clear  fluid  forms  the 
hyposulphite  of  lime,  and  it  is  used  for 
defecating  saccharine  matters.  When 
this  solution  is  used  it  is  mixed  with 
eight  parts  of  water. 

LINEN.  A  species  of  cloth  woven 
with  the  fibres  of  the  flax  plant  (Linum 
usitatissimitm).  The  origin  of  the  manu- 
facture of  linen  is  lost  in  its  antiquity. 
In  the  time  of  Herodotus  linen  was  an 
article  of  export  from  Egypt,  where  it 
had  been  used  from  time  immemorial ; 
but  it  is  evident  that  in  ancient  times  its 
use  was  limited  to  the  noble  and  the 
rich.  In  modern  times  linen  constitutes  a 
staple  manufacture  in  almost  all  European 
countries ;  but  more  especially  in  Ger- 
many, Russia,  Switzerland,  Flanders, 
England,  Scotland,  and  Ireland.  In 
England  it  has  been  prosecuted  for  a  very 
long  period;  but  until  of  late  years  its 
progress  has  been  inconsiderable,  com- 
pared at  least  with  that  made  in  other 
branches  of  manufacture.    This  seems  to 


be  partly  owing  to  the  attempts  to  bolster 
up  and  encourage  the  manufacture  in  Ire- 
land, partly  to  the  absurd  restrictions  that 


were  tor  a  lengthened  period  laid  on  the 
importation  of  foreign  flax  and  hemp, 
and  partly  to  the  rapid  growth  of  the 
cotton  manufacture — fabrics  of  cotton 
having,  to  a  considerable  extent,  super- 
seded "those  of  linen.  It  is  only  within  the 
last  fifty  years  that  any  machinery  has 
been  used  in  England  in  the  production 
of  linen  cloth,  the  first  mills  for  the  spin- 
ning of  flax  having  been  constructed  at 
Darlington  about  forty-eight  years  ago. 

The  entire  value  of  the  linen  manufac- 
ture of  Great  Britain  and  Ireland  is  esti- 
mated at  £8,000,000,  and  the  total  num- 
ber of  persons  employed  in  it  about 
185,000. 

One  of  the  great  obstacles  which  has 
stood,  in  the  way  of  the  extended  culti- 


up] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


319 


vation  of  flax,  is  the  trouble,  delay,  and 
expense  attendant  on  its  steeping,  and 
preparation  for  the  market.  This  has 
been  now  removed  by  an  invention  which 
dispenses  with  that  process,  and  enables 
the  grower,  at  the  smallest  possible  cost, 
to  send  his  fibre  into  the  market.  By 
this  process,  of  which  Mr.  Doulan  is  the 
inventor,  the  results  are  obtained  by  a 
combination  of  chemical  and  mechanical 
processes,  and  all  expenses  connected 
with  steeping  being  avoided,  the  fibre 
may  be  prepared  at  a  cost  considerably 
below  the  present  process,  and  may  be 
made  applicable  for  the  coarsest  nail  bags, 
or  canvas,  or  for  the  finest  Brussels  lace. 

Not  only  the  expense,  but  the  time  is  I 
also  less,  which  is  consumed  in  the  pre-  j 
paration  of  the  fibre.    In  the  old  way  this  \ 
occupied  from  10  days  to  3  weeks.    By  j 
the  unsteeped  mode  as  many  hours  sut-  j 
flee.    The  fibre  produced  is  also   clean  j 
and  in  its  natm-al  state,  and  its  strength  j 
is  regular  and  uniform.    These  two  last  | 
qualities  being  found  to  be  constant  in  : 
the  unsteeped  flax,  has  led  to  adaptation  j 
of  it  to  cotton  machinery.    The  patentee  j 
of   the    invention    is    the  Chevalier  P.  \ 
Claussen,  member  of  the  Brazilian  Insti- 
tute, the  inventor  of  the  circular  loom,  i 
The  patent  granted  is  for  the  preparation  \ 
of  flax  in  a  short  staple,  so  as  to  produce 
a  substitute  for  wool  and  cotton,  capable  ! 
of  being  spun  on  cotton  machinery  ;  and 
also  for  the  mixture  of  the  materials  thus 
obtained,  which  can  be  carded  together  j 
with  silk,  cotton,  or  wool,  or  separately  I 
as  cotton  for  spinning  into  yarn.     The 
right  is  likewise  secured  for   preparing 
long  fibre  as  a  substitute  for  silk,   for 
bleaching  in  the  preparation  of  materials, 
for  spinning  and  felting,  and  also  in  yarns 
and  felts.    Prom  1}  cwt.  of  the  flax  fibre, 
prepared  andcleanpd  upon  the  unsteeped 
process,  1  cwt.  of  a  substance  identical 
with  clean  cotton  can  be  produced  at  a 
cost  of  56  cents  for  materials.     The  cost 
of  manual  or  mechanical  labor  required 
in    the    preparation,    including   the   ex- 
penses of  bleaching,   an   operation  per- 
formed in  a  few  seconds,  does  not  amount 
to  more  than  nineteen  twentieths  of  a  cent 
per   pound.      The   mixture   of  the  two 
substances,  viz.,  wool  with  fiax,  reduced 
to  short  staple,  forms  a  fabric  exceedingly 
durable,  while  its  cost  may  be  judged  by 
the  fact,  that  while  wool  costs  one  dollar, 
the  flax  prepared  and  ready  for  spinning 
may  be  had  for  12i  cents  per  lb. ;  so  that 
with  flax  and  wool  spun  together  in  equal 
quantities,  the  cost  would  be  reduced  by 
nearly  one  half. 


LINE,  in  decimal  measures  the  10th, 
and  in  duodecimals  the  12th  of  an  inch, 
French  or  English  ;  the  French  inch  be- 
ins:  to  the  English  as  1  to  1-065977. 

"LINIMENT  OF  AMMONIA,  is  a 
mixture  of  equal  parts  of  olive-oil  and 
caustic-water  of  ammonia.  It  is  a  useful 
application  for  sore  throats,  rheumatic 
pains,  &c.  A  stronger  liniment  is,  two 
parts  of  olive-oil,  with  one  solution  of 
ammonia. 

Liniment  of  camphor,  is  4  olive-oil,  1 
camphor.  The  compound  liniment  is,  3 
solution  of  ammonia,  and  8  spirit  of  lav- 
ender distilled,  and  1  camphor  dissolved, 
with  j  tincture  of  opium  added. 

Liniment  for  burns  and  scalds. — Take 
of  borate  of  soda  li  dr. ;  rose-water,  2 
drs. ;  lime-water,  2i  oz. ;  oil  of  sweet 
almonds,  3  oz.  Soak  lint  in  this  mix- 
ture, and  apply  to  the  affected  parts. 
Turpentine  is  also  a  good  liniment,  or 
any  spirits. 

LINING.  In  architecture,  any  cover- 
ing of  an  interior  surface.  The  linings, 
for  instance,  or  boxings  of  window  shut- 
ters, are  the  pieces  forming  the  backs  of 
the  recesses  into  which  the  shutters  are 
folded.  In  doorways,  they  are  the  facings 
on  each  side  the  aperture :  to  sashes, 
they  are  the  vertical  pieces  parallel  with 
the  surface  of  the  walls. 

LINSEED  contains,  in  its  dry  state, 
11-265  of  oil;  0-146  of  wax;  2-488  of  a 
soft  resin ;  0-550  of  a  coloring  resinous 
matter ;  0926  of  a  yellowish  substance 
analogous  to  tannin  ;  6-154  of  gum;  15-12 
of  vegetable  mucilage;  1-48  of  starch; 
2.932  of  gluten;  2-782  of  albumine ; 
10-884  of  saccharine  extractive;  44-382  of 
envelopes,  including  some  vegetable 
mucilage.  It  contains  also  free  acetic 
acid ;  some  acetate,  sulphate,  and  muri- 
ate of  potash,  phosphate  and  sulphate  of 
lime;  phosphate  of  magnesia;  and  silica. 
{See  Oils.) 

LINTEL.  In  architecture,  an  horizon- 
tal piece  of  timber  or  stone,  over  a  door, 
window,  or  other  opening,  to  discharge 
the  superincumbent  weight. 

LIP-SALVE  {white)."  Melt  together 
equal  weights  of  v^hite  wax,  white  sugar- 
candy,  spermaceti,  and  olive-oil. 

Or  {red).  Melt  together  4  oz.  of  white 
wax,  5  oz.  of  olive-oil,  4  drs.  of  sperma- 
ceti, and  add  20  drops  of  oil  of  lavender, 
and  2  oz.  of  alkanet  root.  Or,  2  oz.  of 
best  olive-oil,  3  oz.  of  spermaceti  and  of 
white  wax,  with  4  drs.  of  alkanet  root ; 
melt,  strain,  and  add  3  drops  of  oil  of 
rhodium  wood.  Or,  melt  together  2  oz. 
of  white  wax,  3  oz.  of  spermaceti,  and  6 


320 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[liq 


oz.  of  oil  of  almonds,  and  add  1  oz.  of 
alkanetroot,  and  2  drs.  of  balsam  of  Peru. 

LIQUATION  is  the  process  of  sweat- 
ing out,  by  a  regulated  heat,  from  an 
alloy,  an  easily  fusible  metal  from  the  in- 
terstices of  a  metal  difficult  of  fusion. 
Lead  and  antimony  are  the  metals  most 
commonly  subjected  to  liquation ;  the 
former  for  the  purpose  of  carrying  off  by 
a  superior  affinity  the  silver  present  in 
any  complex  alloy,  a  subject  discussed 
under  Silver. 

LIQUID  AMBER  is  the  produce  of 
the  liquid-amber  sty raciflora,  a  tree  which 
grows  in  Mexico,  Virginia,  and  Louisiana. 
Occasionally  it  is  of  an  oily  consistence, 
at  other  times  thick  like  turpentine.  It  is 
translucent,  yellow,  of  a  pleasant  odor,  and 
aromatic  flavor,  somewhat  pungent.  It 
dissolves  almost  in  boiling  alcohol.  It 
contains  much  Benzoic  acid,  which  ex- 
udes when  the  fluid  hardens  bv  keeping. 

LIQUEURS,  LIQUORISTE;  names 
given   by   the   French    to   liquors   com- 

Sonnded  of  alcohol,  water,  sugar,  and 
ifferent  aromatic  substances  ;  and  to  the 
person  who  compounds  them.  There  are 
given  here,  on  Dr.  Ure's  authority,  a 
few  of  their  most  approved  recipes. 

Infusion  of  the  peels  of  fruits. — The 
oute'r  skin,  pared  off  with  a  sharp  knife, 
is  to  be  dropped  into  a  hard  glazed  jar, 
containing  alcohol  of  34°  B.,  diluted 
with  half  its  bulk  of  water,  and  the  whole 
is  to  be  transferred  into  well-corked  car- 
boys. After  an  infusion  of  six  weeks, 
with  occasional  agitation,  the  aromatized 
spirit  is  to  be  distilled  off.  In  this  way 
are  prepared  the  liquors  of  cedrat, 
lemons,  oranges,  limettes  (a  sort  of  sweet 
lemon),  poncires  (the  large  citron),  ber- 
gamots  &c, 

Infusion  of  aromatic  seeds. — These  must 
be  pounded,  put  into  a  carboy,  along 
with  alcohol  diluted  as  above,  infused 
with  agitation  for  six  weeks,  and  then 
distilled. 

Infusions  of  aromatic  woods  are  made 
in  the  same  way. 

The  liquorist  should  not  bring  his  in- 
fusions and  tinctures  into  the  market  till 
six  months  after  their  distillation. 

Liqueurs  have  different  titles,  accord- 
ing to  their  mode  of  fabrication. 

Thus  waters  are  liquors  apparently 
devoid  of  viscidity  ;  creams  and  oils  pos- 
sess it  it  a  high  degree. 

Water  of  cedrat  is  made  by  dissolving 
six  pounds  of  sugar  in  seven  quarts  of 
water;  adding  two  quarts  of  spirit  of 
cedrat,  and  one  of  spirit  of  citron.  Boil 
the  whole  for  a  minute,  and  filter  hot 


through  a  proper  bag.  Set  it  fcr  a  con- 
siderable time  aside  in  a  corked  carboy, 
before  it  be  bottled. 

Oil  or  cream  of  cedrat. — Take  eight 
quarts  of  river  water,  two  of  spirit  of 
cedrat,  one  of  spirit  of  citron,  and  as 
much  rich  sirup  as  is  necessary  to  give 
the  mixture  an  oily  consistence.  Stir  it 
well  and  set  it  aside  in  carboys.  Should 
it  be  at  all  clouded,  it  must  be  filtered 
till  it  be  perfectly  pellucid. 

Balm  of  Molucca,  is  made  by  infusing 
for  ten  days,  in  a  carboy  capable  of  hold- 
ing fully  four  gallons,  10  pounds  of  spirits 
of  18°  B.,  4  pounds  of  white  sugar,  4 
pounds  of  river  water,  4  drachms  of 
pounded  cloves,  and  48  grains  of  pounded 
mace.  The  mixture  is  to  be  shaken  3  or  4 
times  daily,  colored  with  caramel  (burnt 
sugar),  filtered  at  the  end  of  ten  days, 
and  set  aside  in  bottles. 

Tears  of  the  widow  of  Malabar,  are  com- 
pounded with  the  preceding  quantity  of 
spirits,  sugar,  and  water,  adding  4 
drachms  of  ground  cinnamon,  48  grains 
of  cloves,  and  a  like  quantity  of  mace, 
both  in  powder.  It  may  be  slightly  col- 
ored with  caramel. 

The  deli-ght  of  the  Mandarins. — Take 
spirit,  sugar,  and  water,  as  above,  adding 
4  drachms  of  anwum  Chinee  (Gingi),  as 
much  amfircite  (seeds  of  the  hibiscus  abel- 
mosc7ms,  Lin.),  all  in  powder:  2  drachms 
of  safflower. 

The  sighs  of  love. — Take  spirits,  water, 
and  sugar,  as  above.  Perfume  with 
essence  (otto)  of  roses  ;  give  a  very  pale 
pink  hue  with  tincture  of  cochineal,  filter 
and  bottle  up. 

Creme  de  macarons. — Add  to  the  spirit, 
sugar,  and  water,  as  above,  half  a  pound 
of  bitter  almonds,  blanched  and  pounded ; 
cloves,  cinnamon,  and  mace  in  powder, 
of  each  48  grains.  A  violet  tint  ]S  given 
by  the  tinctures  of  turnsole  and  cochineal. 
'  Curacoa. — Put  into  a  large  bottle  nearly 
full  of  alcohol  of  trente-six  (34°  Baume), 
the  peels  of  six  smooth  Portugal  oranges, 
(Seville  ?)  and  let  them  infuse  for  15  days ; 
then  put  into  a  carboy  10  pounds  of 
spirits  of  18°  B.,  4  pounds  of  white  sugar, 
and  4  pounds  of  river  water.  "When  the 
sugar  is  dissolved,  add  a  sufficient  quan- 
tity of  the  orange  zestes  to  give  flavor, 
then  spice  the  whole  with  48  grains  of 
cinnamon,  and  as  much  mace,  both  in 
powder.  Lastly  .introduce  an  ounce  of 
ground  Brazilwood,  and  infuse  during  10 
days,  agitating  3  or  4  times  daily.  A 
pretty  deep  hue  ought  to  be  given  with 
caramel. 

LIQUORICE.— Glycyrrhiza  glabra,  tho 


lit] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


321 


plant  which  produces  the  liquorice  of  the 
shops,  is  cultivated  in  England  for  the 
use  of  brewers  and  distillers,  but  liquor- 
ice is  manufactured  from  it  only  in  Sicily 
and  Spain.  It  grows  natural! v  near  Pon- 
tefract  and  Languedoc,  in  alt  the  Medi- 
terranean countries,  and  in  such  abund- 
ance in  Sicily  that  it  is  considered  a  great 
scourge  to  the  cultivator.  Its  roots  pene- 
trate to  a  great  depth,  and  the  deeper  the 
ground  is  opened,  with  a  view  to  eradi- 
cate them,  so  much  the  more  vigorous  is 
the  succeeding  crop.  The  juice  is  ex- 
pressed from  the  roots,  in  the  same  way 
as  oil  is  from  olives ;  they  are  first  wash- 
ed perfectly  clean,  then  crushed  in  an 
olive  mill,  then  boiled  four  or  five  hours, 
pressed  in  the  olive-press,  and  the  juice 
slowly  boiled,  and  evaporated  in  an  iron 
vessel. 

LITHARGE,  is  the  crystals  of  melted 
lead  left  to  cool,  and  is  formed  also  in  the 
refinement  of  silver.  It  removes  acidity 
in  wines,  but  renders  them  highly  per- 
nicious, and  the  use  of  it  is  deeply  crim- 
inal.   It  is  a  fused  protoxide  of  lead. 

LITHIA,  a  rare  alkali,  discovered  by 
Arfwedson  in  a  mineral  called  petalite. 
It  is  also  found  in  spodumene,  and  a  few 
other  minerals.  It  is  known  from  potash 
and  soda  by  its  carbonate  being  difficultly 
soluble — from  baryta,  strontia,  and  lime, 
by  the  solubility  of  the  sulphate  and  oxa- 
late, and  from  magnesia  by  its  carbonate 
having  alkaline  properties.  It  is  the  oxide 
of  the  metal  lithium;  its  equivalent  is  10, 
and  that  of  the  oxide  18. 

LITHIC,  or  Uric  acid,  one  of  the  con- 
stituents of  urine  :  in  that  of  the  serpent 
species  it  is  found  in  great  abundance. 
It  exists  largely  also  in  guano,  united 
with  ammonia.  Occasionally  it  is  formed 
in  excess  in  the  system,  and  is  thrown 
off  bythe  kidneys  undissolved,  forming 
the  uric  acid  calculus. 

LITHIUM,  is  a  white  alkaline  metal, 
lighter  than  potassium,  and  its  oxide  is 
the  alkali  called  Lithia. 

LITHOGRAPHY,  is  the  art  of  throw- 
ing ofF  impressions,  upon  paper,  of  fig- 
ures and  writing  previously  traced  upon 
stone.  It  has  been  partly  treated  of  un- 
der the  head  "  engraving."  The  pro- 
cesses of  this  art  aie  founded : — 

1.  Upon  the  adhesion  to  a  smoothly-po- 
lished limestone  of  an  encaustic  fat  which 
forms  the  lines  or  traces. 

2.  Upon  the  power,  acquired  by  the 
parts  penetrated  by  this  encaustic,  of  at- 
tracting to  themselves,  and  becoming  co- 
vered with  a  printer's  ink,  having  linseed 
oil  for  its  basis. 

14* 


3.  Upon  the  interposition  of  a  film  of 
water,  which  prevents  the  adhesion  of 
the  ink  in  all  the  parts  of  the  surface  of 
the  stone  not  impregnated  with  the  en- 
caustic. 

4.  Lastly,  upon  a  pressure  applied  by 
the  stone,  such  as  to  transfer  to  paper  the 
greater  part  of  the  ink  which  covers  the 
greasy  tracings  of  the  encaustic. 

The  lithographic  stones  of  the  best 
quality  are  still  procured  from  the  quarry 
of  Solenhofen,  a  village  at  no  great  dis- 
tance from  Munich,  where  this  mode  of 
printing  had  its  birth.  They  resemble  in 
their  aspect  the  yellowish  white  lias  of 
Bath,  but  their  geological  place  is  much 
higher  than  the  lias.  Abundant  quarries 
of  these  fine-grained  limestones  occur  in 
the  county  of  Pappenheim,  along  the 
banks  of  the  Danube,  presenting  slabs  of 
every  required  degree  of  thickness,  part- 
ed by  regular  seams,  and  ready  for  remo- 
val with  very  little  violence.  The  good 
auality  of  a  lithographic  stone  is  generally 
enoted  by  the  following  characters  :  its 
hue  is  of  a  yellowish  gray,  and  uniform 
throughout ;  it  is  free  from  veins,  fibres, 
and  spots ;  a  steel  point  makes  an  im- 
pression on  it  with  difficulty ;  and  the 
splinters  broken  off  from  it  by  the  ham- 
mer display  a  conchoidal  fracture.  A 
new  locality  affording  fine  stone  is  at  Bel- 
beze,  Haute  Garonne,  in  French  Pyrenees : 
they  are  found  in  the  chalk  formation, 
which  is  a  peculiarity.  This  Continent 
does  not  as  yet  appear  to  contain  any  li- 
thographic stone  of  good  quality. 

The  Munich  stones  are  retailed  on  the 
spot  in  slabs  or  layers  of  equal  thickness ; 
they  are  quarried  with  the  aid  of  a  saw, 
so  as  to  sacrifice  as  little  as  possible  of 
the  irregular  edges  of  the  rectangular  ta- 
bles or  plates.  One  of  the  broad  faces  is 
then  dressed  and  coarsely  smoothed. 
The  thickness  of*  these  stones  is  nearly 
proportional  to  their  other  dimensions ; 
and  varies  from  an  inch  and  two-thirds 
to  3  inches. 

In  each  lithographic  establishment,  the 
stones  receive  their  finishing,  dressing, 
and  polishing  ;  which  are  performed  like 
the  grinding  and  polishing  of  mirror 
plate.  The  work  is  done  by  hand,  by 
rubbing  circularly  a  movable  slab  over 
another  cemented  in  a  horizontal  position, 
with  fine  sifted  sand  and  water  interpos- 
ed between  the  two.  The  style  of  work 
that  the  stone  is  intended  to  produce  de- 
termines the  kind  of  polish  that  it  should 
get.  For  crayon  drawing  the  stone  should 
be  merely  grained  more  or  Jess  fine,  ac- 
cording to  the  fancy  of  the  draughtsman. 


322 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[lit 


The  higher  the  finish  of  the  surface,  the 
softer  are  the  drawings  ;  but  the  printing 
process  becomes  sooner  pasty,  and  a 
smaller  number  of  impressions  can  be 
taken.  Works  in  ink  require  the  stone  to 
be  more  softened  down,  and  finally  po- 
lished with  pumice  and  a  little  water. 
The  stones  thus  prepared  are  packed  for 
use  with  white  paper  interposed  between 
their  faces. 

Lithographic  crayons. — Fine  lithogra- 
phic prints  cannot  be  obtained  unless  the 
crayons  possess  every  requisite  quality. 
The  ingredients  composing  them  ought 
to  be  of  such  a  nature  as  to  adhere  strong- 
ly to  the  stone,  both  after  the  drawing 
has  undergone  the  preparation  of  the 
acid,  and  during  the  press-work.  They 
should  be  hard  enough  to  admit  of  a  fine 
point,  and  trace  delicate  lines  without 
risk  of  breaking.  The  following  compo- 
sition has  been  successfully  employed  for 
crayons  by  M  M.  Bernard  and  Delarue, 
at  Paris : — 

Pure  wax,  (first  quality) 4 

Dry  white  tallow  soap 2 

White  tallow 2 

Gum  lac 2 

Lamp  black,  enough  to  give  a  dark  tint .  .1 
Occasionally  copal  varnish 1 

A  simpler  ink  is  as  follows:  White 
soap  6  parts,  white  wax  6  parts,  lamp 
black  1  part,  well  fused  together. 

Lithographic  ink  is  prepared  in  nearly 
the  same  way,  viz. :  wax  16  parts,  tallow 
6  parts,  hard  soap  6  parts,  shellac  12  parts, 
mastic  8  parts,  Venice  turpentine  1  part, 
lamp  black  4  parts.  These  are  to  be 
ground  and  heated  together  carefully. 

The  use  of  autographic  paper  is  an  im- 

J movement  in  lithography,  as  it  abridges 
abor  and  does  away  with  the  necessity  of 
making  the  drawing  on  the  stone  revers- 
ed. The  drawing  is  made  on  this  paper 
and  then  transferred  to  the  stone.  The 
ink  for  this  purpose  must  be  fatter  than 
that  intended  for  the  stone,  and  may  be 
made  of  white  soap  and  white  wax  of 
each  10  parts,  mutton  suet  and  lamp  black 
of  each  3  parts,  shellac  and  mastic  of  each 
5  parts.  These  are  to  be  melted  and  well 
incorporated  together. 

Lithographic  paper. — Lay  on  the  paper, 
3  successive  coats  of  sheep-feet  jelly,  1 
layer  of  white  starch,  1  layer  of  gamboge. 
The  first  layer  is  applied  with  a  sponge 
dipped  in  the  solution  of  the  hot  jelly, 
very  equally  over  the  whole  surface,  but 
thin  ;  and  if  the  leaf  be  stretched  upon  a 
cord,  the  gelatine  will  be  more  uniform. 
The  next  two  coats  are  to  be  laid  on,  un- 
til each  is  dry.    The  layer  of  starch  is 


then  to  be  applied  with  a  sponge,  and  it 
will  also  be  very  thin  and  equal.  The 
coat  of  gamboge  is  lastly  to  be  applied  in 
the  same  way.  When  the  paper  is  dry, 
it  must  be  smoothed  by  passing  it  through 
the  lithographic  press ;  and  the  more  po- 
lished it  is,  the  better  does  it  take  on  the 
ink  in  fine  lines. 

Transfer. — When  the  paper  is  moisten- 
ed, the  transfer  of  the  ink  from  the  gam- 
boge is  perfect  and  infallible.  The  starch 
separates  from  the  gelatine,  and  if,  after 
taking  the  paper  off  the  stone,  we  place 
it  on  a  white  slab  of  stone,  and  pour  hot 
water  over  it,  it  will  resume  its  primitive 
state. 

The  coat  of  gamboge  ought  to  be  laid 
on  the  same  day  it  is  dissolved,  as  by 
keeping  it  becomes  of  an  oily  nature ;  in 
this  state  it  does  not  obstruct  the  transfer, 
but  it  gives  a  gloss  to  the  paper  which 
renders  the  drawing  or  tracing  more  dif- 
ficult, especially  to  persons  little  habitu- 
ated to  lithography. 

The  starch-paste  can  be  employed  only 
when  cold,  the  day  after  it  is  made,  and 
after  having  the  skin  removed  from  its 
surface. 

A  leaf  of  such  lithographic  paper  may 
be  made  in  two  minutes. 

In  transferring  a  writing,  an  ink  draw- 
ing, or  a  lithographic  crayon,  even  the 
impression  of  a  copper-plate,  to  the  stone, 
it  is  necessary,  1 ,  that  the  impression  be 
made  upon  a  thin  and  slender  body  like 
common  paper  ;  2,  that  they  may  be  de- 
tached and  fixed  totally  on  the  stone  by 
means  of  pressure  ;  but  as  the  ink  of  a 
drawing  sinks  to  a  certain  depth  in  paper, 
and  adheres  pretty  strongly,  it  would  be 
difficult  to  detach  all  its  parts,  were  there 
not  previously  put  between  the  paper  and 
the  traces,  a  body  capable  of  being  sepa- 
rated from  the  paper,  and  of  losing  its  ad- 
hesion to  it  by  means  of  the  water  with 
which  it  is  damped.  In  order  to  produce 
this  effect,  the  paper  gets  a  certain  pre- 
paration, which  consists  in  coating  it  over 
with  a  kind  of  paste  ready  to  receive 
every  delineation  without  suffering  it  to 
penetrate  into  the  paper.  There  are  dif- 
ferent modes  of  communicating  this  pro- 
perty to  paper.  Besides  the  above,  the 
following  may  be  tried  :  Take  an  unsized 
paper,  rather  strong,  and  cover  it  with  a 
varnish  composed  of: — 

Starch 120  parts 

Gum  arable 40  — 

Alum 20  — 

A  paste  of  moderate  consistence  must 
be  made  with  the  starch  and  some  water, 


LITHOGRAPHIC  I'Rht-S.       p.  322. 


LOC] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


323 


with  the  aid  of  beat,  into  which  the  gum 
and  alum  are  to  be  thrown,  each  previ- 
ously dissolved  in  separate  vessels. 
When  the  whole  is  well  mixed,  it  is  to  be 
applied,  still  hot,  on  the  leaves  of  paper, 
with  a  flat  smooth  brush.  A  tint  of  yel- 
low color  may  be  given  to  the  varnish, 
with  a  decoction  of  the  berries  of  Avig- 
non, commonly  called  French  berries  by 
our  dyers.  The  paper  is  to  be  dried,  and 
smoothed  by  passing  under  the  scraper 
of  the  lithographic  press. 

Steel  pens  are  employed  for  writing  and 
drawing  with  ink  on  the  lithographic 
stones. 

L1THOMARGE.  Stone  marrow,  a 
variety  of  talc  of  various  colors,  and  ge- 
nerally associated  with  magnesian  mine- 
rals. 

LITMUS  is  prepared  in  Holland  from 
the  species  of  lichen  called  faecanora  tar- 
tarea,  Eocella  tartarea,  by  a  process  which 
has  been  kept  secret,  but  which  is  un- 
doubtedly analogous  to  that  for  making 
archil  and  cudbear.  The  ground  lichens 
are  first  treated  with  urine  containing  a 
little  potash,  and  allowed  to  ferment, 
whereby  they  produce  a  purple  red ;  the 
colored  liquor,  treated  with  quicklime 
and  some  more  urine,  is  set  again  to  fer- 
ment during  two  or  three  weeks,  then  it 
is  mixed  with  chalk  or  gypsum  into  a 
paste,  which  is  formed  into  small  cubical 

Eieces,  and  dried  in  the  shade.  Litmus 
as  a  violet-blue  color,  is  easy  to  pulver- 
ize, is  partially  soluble  in  water  and  dilute 
alcohol,  leaving  a  residuum  consisting  of 
carbonate  of  lime,  of  clay,  silica,  gypsum, 
and  oxyde  of  iron  combined  with  the  dye. 
The  color  of  litmus  is  not  altered  by  al- 
kalies, but  is  reddened  by  acids  ;  and  is, 
therefore,  used  in  chemistry  as  a  delicate 
test  of  acidity,  either  in  the  state  of  solu- 
tion or  of  unsized  paper  stained  with  it. 
It  is  emploved  to  dye  marble  blue. 
#  LIXIVIATION  signifies  the  abstrac- 
tion by  water  of  the  soluble  alkaline  or 
saline  matters  present  in  an  earthy  ad- 
mixture ;  as  from  that  of  quicklime  and 
potashes  to  make  potash  ley,  from  that  of 
effloresced  alum  schist  to  make  aluminous 
liquors,  &c. 

LOADSTONE,  MAGNETIC  IRON- 
STONE. An  iron  ore  consisting  of  the 
protoxyde  and  peroxyde  of  iron  in  a  state 
of  combination. 

LOAM,  contains  87  of  sand  as  fine  as 
meal,  and  18  of  clay,  according  to  the  an- 
alysis of  Kirwan. 

It  is  a  natural  mixture  of  clay  and  sand. 
The  colored  clays  and  loams  participate 
of  iron;  hence,  many  of  these  melt  in  a 


strong  fire,  without  any  addition ;  both 
clay  itself,  and  mixtures  of  it  with  crys- 
talline earths,  being  brought  into  fusion 
by  ferruginous  oxides,  though  the  fusible 
mixtures  of  clay  and  calcareous  earths  are, 
by  the  same  ingredient,  prevented  from 
melting.  The  bricks  made  from  some 
loams,  are,  when  moderately  burnt,  re- 
markably free,  so  as  to  be  easily  rubbed 
smooth,  cut,  sawed,  grooved,  &c.  Hence 
their  use  in  building  furnaces,  &c. 

LOCK,  in  Internal  Navigation,  is  a 
part  of  a  canal  included  between  two 
floodgates,  by  means  of  which  a  vessel  is 
transferred  from  a  higher  to  a  lower  level, 
or  from  a  lower  to  a  higher. 

On  the  Monkland  Canal,  at  Blackhill 
Locks  (Scotland),  the  waste  of  water, 
time,  and  labor,  have  been  obviated  by 
the  substitution  of  a  steep  incline,  with 
rails  and  water  tight-cradles.  The  boat 
is  floated  into  one  of  the  latter,  when  it 
is  drawn  up  by  a  wire  rope  worked  with 
drums,  by  the  power  of  a  steam  engine 
aided  by  the  descending  cradle  filled  with 
water.  In  five  minutes  a  boat  is  hoisted 
up  the  incline,  numbering  eight  large 
locks,  at  very  little  expense,  and  with  the 
waste  of  no  more  water  than  that  dis- 
placed by  each  boat  when  floated  into  its 
cradle.  The  engineer  is  a  Mr.  Leslie,  of 
Edinburgh,  who  has  adopted  this  plan 
from  American  practice. 

LOCK.  An  instrument  composed  of 
springs  and  bolts,  used  to  fasten  doors, 
drawers,  chests,  &c.  It  is  an  improve- 
ment on  the  primitive  latch  or  bolt,  with 
a  crooked  stick  or  instrument,  to  turn  it 
through  a  hole  on  the  outside.  Obsta- 
cles are  opposed  inside,  and  then  the  ac- 
commodating the  key  to  pass  them,  con- 
stitutes its  wards,  the  object  being  merely 
to  turn  and  unturn  a  bolt,  now  called 
locking  and  unlocking.  On  the  number 
and  complication  of  the  obstacles  in  car- 
riyng  the  key  to  the  bolt,  so  as  to  turn  it, 
depends  the  perfection  of  the  lock.  The 
spring-lock  consists  of  the  main  plate, 
the  cover-plate,  and  the  pin-hole.  In, 
and  on  the  main  plate,  is  the  key-hole, 
the  top-hook,  the  cross-wards,  the  bolt- 
knob,  the  tumbler  and  its  pin,  and  the 
staples.  To  the  cover-plate  is  affixed  the 
main,  cross,  and  step-wards,  and  the 
pin.  With  the  pin-hole  are  connected 
the  hook,  cross,  and  bow-wards,  and  the 
bit. 

A  good  lock  is  the  master-piece  in 
smith  ery,  and  requires  much  art  and  deli- 
cacy in  contriving  and  varying  the  wards, 
springs,  bolts,  and  other  parts  whereof 
it  is  composed,  so  as  to  adjust  them  to 


324 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[loc 


the  plates  where  they  are  serviceable,  and 
to  the  various  occasions  of  their  use.  The 
structure  of  locks  is  so  varied,  and  the 
number  of  inventions  of  different  sorts 
so  extended,  that  we  cannot  attempt  to 
enumerate  them.  Those  placed  on  outer 
doors  are  called  stock  locks,  those  on 
chamber  door  spring  locks,  and  such  as 
are  hidden  in  the  thickness  of  the  doors 
to  which  they  are  applied  are  called  mor- 
tise locks.  The  padlock  is  too  well  known 
to  need  description.  We  here  add  the 
conditions  which,  to  Mr.  Nicholson,  ap- 
pear necessary  in  a  lock  of  the  most  per- 
tect  kind  :  1.  That  certain  parts  of  the 
lock  should  be  variable  in  position  through 
a  great  number  of  combinations,  one  only 
of  which  shall  allow  the  lock  to  be  opened 
or  shut.  2.  That  this  last  mentioned  com- 
bination should  be  variable  at  the  pleas- 
ure of  the  possessor.  3.  That  it  should 
not  be  possible,  after  the  lock  is  closed  and 
the  combination  disturbed,  for  any  one, 
not  even  the  maker  of  the  lock,  to  dis- 
cover, by  any  examination,  what  may  be 
the  proper  situations  of  the  parts  required 
to  open  the  lock.  4.  That  trials  of  this 
kind  shall  not  be  capable  of  injuring  the 
works.  5.  That  it  shall  require  no  key  ; 
6.  And  be  as  easily  opened  in  the  dark  as 
in  the  light.  7.  That  the  opening  and 
shutting  should  be  done  by  a  process  as 
simple  as  that  of  a  common  lock.  8. 
That  it  should  open  without  a  key,  or 
with  one,  at  pleasure.  9.  That  the  key- 
hole be  concealed,  defended,  or  inaccessi- 
ble. 10.  That  they  may  be  used  by  a 
stranger,  without  his  knowing  or  being 
able  to  discover  the  adopted  combination, 
11.  That  the  key  be  capable  of  adjust- 
ment to  all  the  variations  of  the  lock, 
and  yet  be  simple.  12.  That  the  lock 
should  not  be  liable  to  be  taken  off  and 
examined,  whether  the  receptacle  be  open 
or  shut,  except  by  :>ne  who  knows  the 
adopted  combination.  These  considera- 
tions involve  a  mechanical  problem  of 
great  difficulty ;  but  much  towards  its 
accomplishment  has  been  effected  in  va- 
rious inventions  that  have  been  promul- 
gated, and  more  especially  in  those  of 
Bramah,  Chubb,  Tavlor,  <fec. 

LOCOMOTION.  'Such  motion  as  is 
attended  by  change  of  place  in  the  body 
which  moves,  in  contradistinction  to  mo- 
tions which  a  body  may  have  which  is 
stationary.  Thus,  a  clock,  a  mill,  a  lathe 
moves;  but  no  change  of  place  of  the 
machine  is  produced  :  such  motion  is  not 
locomotion.  A  steam  engine  which  being  i 
fixed  in  its  position,  impels  others  bodies,  ! 
is  a  stationary   engine  ;  but  one  which 


travels  with  the  bodies  which  it  drives 
is  called  a  locomotive  engine. 

LOCOMOTIVE  ENGINE.  Any  en- 
gine which,  being  employed  to  draw  loads 
in  transport  overland,  travels  with  the 
load  which  it  draws. 

Since  the  improvement  and  extension 
of  iron  railways,  this  term  has  been  ex- 
clusively applied  to  the  steam  engine,  by 
which  loads  are  drawn  upon  them.  Al- 
though, strictly  speaking,  the  steam  en- 
gine by  which  a  ship  is  propelled  is  a  lo- 
comotive engine,  it  is  not  usual  to  apply 
that  term  to  it ;  such  an  engine  is  called 
a  marine  engine.  (See  Steam  Naviga- 
tion.) The  term  locomotive  engine  must, 
therefore  as  at  present  used,  be  under- 
stood to  mean  the  travelling  steam  engine 
by  which  trains  are  drawn  on  railways. 

History  of  the  Locomotive  Engine. — 
The  first  practical  application  of  the 
steam  engine  as  a  locomotive  power  took 
place  in  1804,  on  a  railroad  at  Merthyr 
Tydvil,  in  South  Wales.  The  engine  was 
constructed  by  Messrs.  Trevethick  and 
Vivian,  under  a  patent  obtained  by  them 
two  years  previously.  This  engine,  in 
several  respects,  resembled  in  its  form 
and  structure  those  which  have  been 
since  used  for  a  like  purpose. 

The  boiler  was  a  cylinder,  with  flat  cir- 
cular ends  placed  upon  its  side.  A  large 
tube  entered  it  at  one  ene  end,  and,  being 
carried  near  the  other,  was  there  received 
and  carried  back  parallel  to  its  first  direc- 
tion ;  its  course  through  the  boiler  resem- 
bling the  letter  U.  The  two  mouths  or 
openings  of  this  tube  were  therefore  placed 
at  the  same  end  of  the  boiler.  One  of  the 
mouths  of  this  tube  communicated  with 
the  chimney,  the  base  of  which  was  flanged 
upon  it,  and  the  other  contained  the 
grate  and  furnace.  The  flame  and  heated 
air  were  drawn  through  the  curved  tube, 
and  up  the  chimney.  The  engine  was 
worked  by  high-pressure  steam  without 
condensation  ;  the  steam  being  admitted 
to  the  cylinder,  and  withdrawn  from 
it,  by  the  well-known  mechanical  contri- 
vance called  a  four-way  cock.  The  cyl- 
inder was  placed  on  its  side  ;  and  in  one 
position  or  the  cock  a  communication 
was  opened  between  the  boiler  and  one 
end  of  the  cylinder,  while  another  com- 
munication was  opened  between  the 
other  end  of  a  cylinder  and  a  tube  lead- 
ing to  the  chimney.  Steam  was  thus  ad- 
mitted to  act  on  one  side  of  the  piston, 
and  allowed  to  escape  from  the  other 
side  to  the  chimney.  When  the  piston 
attained  the  end  of  the  stroke  the  posi- 
tion of  the  cock  was  reversed,  and  the 


LOC] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


325 


steam  which  had  just  driven  the  piston 
in  one  direction  was  allowed  to  escape 
to  the  chimney,  while  steam  from  the 
boiler  was  admitted  on  the  other  side 
of  the  piston,  to  impel  it  in  the  contrary 
direction  ;  and  in  this  manner  the  piston 
was  continually  driven  backwards  and 
forwards,  in  a  horizontal  direction,  and 
parallel  to  the  direction  of  the  load.  The 
piston  rod  was  moved  through  a  hole  cor- 
responding with  it  in  magnitude,  in  the 
cover  of  the  c}*linder,  in  which  it  was  ren- 
dered steam  tight  by  a  stuffing  box  proper- 
ly lubricated.  The  piston  rod  acted  by 
means  of  a  connecting  rod  on  a  crank,  which 
it  kept  in  revolution  in  the  same  manner 
as  the  crank  in  a  common  double-acting 
steam  engine  is  moved.  {See  Steam  En- 
gine.) On  the  axle  of  this  crank  was 
placed  a  cogged  wheel  which  by  means  of 
ordinary  gearing,  conveyed  motion  to  the 
axle  of  the  hind  wheels  of  the  engine,  so 
as  to  keep  that  axle  in  constant  revolu- 
tion. The  wheels  being  keyed  upon  that 
axle,  so  as  not  to  be  capable,  like  the 
wheels  of  a  common  carriage,  of  turning 
upon  it  were  necessarily  made  to  revolve 
with  it ;  and  so  long  as  their  pressure 
upon  the  road  was  sufficient  to  prevent 
them  from  slipping,  a  progressive  mo- 
tion of  the  carriage  was  the  necessary 
consequence  of  their  revolution. 

The  early  projectors  of  locomotive  en- 
gines were  all  impressed  with  a  notion 
that  the  adhesion  of  the  driving  wheels 
with  the  rails  must  be  insufficient  to  en- 
able the  power  applied  to  these  wheels  to 
give  progr^sive  motion  to  the  carriage  ; 
and,  without  thinking  it  necessary  to  as- 
certain by  actual  experiment,  whether 
such  were  really  the  case  or  not,  they  ex- 
pended much  ingenuity  and  capital  in  de- 
vising means  of  overcoming  this  difficul- 
ty, which,  after  all  turned  out  to  be 
merely  imaginary.  Engineers  were,  in 
fact,  impressed  with  a  notion  that  if  any 
power  compelled  the  wheels  to  revolve, 
they  would  merely  slip  upon  the  rails, 
and  that  the  carriage  or  engine  would  re- 
main stationary.  To  provide  against  this, 
Messrs.  Trevethick  and  Vivian  proposed 
to  make  the  external  rims  of  the  wheels 
intended  for  common  roads  rough  and 
uneven,  by  surrounding  them  with  pro-  j 
jecting  heads  of  nails  or  bolts,  or  by  cut- 
ting traverse  grooves  in  them.  Seven  ' 
years  afterwards,  Mr.  Blinkensop,  of  ! 
Leeds,  obtained  a  patent  for  a  method  of 
surmounting  this  imaginary  difficulty  by 
the  substitution  of  a  rack  rail  for  the  ordi- 
nary smooth  rail,  and  constructing  teeth 
to  the  driving  wheels  to  work  in  the  teeth 


in  this  track  Various  other  ingenious 
contrivances  were  subsequently  produced 
for  the  same  purpose,  until  about  the  year 
1814,  when  experience  at  length  forced 
upon  engineers  the  knowledge  of  the  fact, 
that  the  adhesion  of  the  tires  of  the 
wheels  with  the  rails  was  amply  sufficient 
to  propel  the  engine,  even  when  drawing 
after  it  a  great  load. 

In  1814,  an  engine  was  constructed  at 
Killingworth  colliery,  near  Newcastle, 
having  two  cylinders  with  a  cylindrical 
boiler,  and  working  two  pair  of  Avheels 
by  cranks  placed  at  right  angles,  so  that 
when  one  was  in  full  operation,  the  other 
was  at  its  dead  points.  By  these  means 
the  propelling  power  was  always  in  ac- 
tion. The  cranks  were  maintained  in 
this  position  by  an  endless  chain,  which 
passed  round  the  two  cog  wheels  placed 
under  the  engine,  and  fixed  on  the  same 
axles  on  which  the  wheels  were  placed. 
The  wheels  in  this  case  were  fixed  on  the 
axles,  and  turned  with  them. 

In  an  engine  subsequently  constructed 
by  Mr.  Stevenson  for  the  same  railway, 
the  mode  adopted  of  connecting  the 
wheels  by  an  endless  chain  and  cog 
wheels  was  abandoned,  and  the  same 
effect  was  produced  by  connecting  the 
two  cranks  by  a  straight  rod.  This 
method  is  still  used  in  the  coupled  en- 
gines which  are  applied  to  draw  the  trains 
of  merchandise  on  the  present  railways. 
The  next  stimulus  which  the  progress 
of  this  invention  received,  arose  from 
the  project  of  constructing  a  railway  be- 
tween Liverpool  and  Manchester,  for  the 
purpose  of  general  traffic.  When  this 
project  was  undertaken  it  was  not  decided 
what  moving  power  was  most  eligible — - 
whether  horse  power,  stationary  steam  en- 
gines, or  locomotive  engines  :  but  the  first 
for  many  obvious  reasons,  was  soon  reject- 
ed, in  favor  of  one  or  other  of  the  last  two. 
The  steam  engine  may  be  applied  to 
move  carriages  on  a  railway  by  two  dis- 
tinct methods.  By  one,  the  engine  is 
fixed  and  draws  a  train  of  carriages 
towards  it  by  a  rope  extending  the  whole 
length  of  the  road  on  which  the  engine 
works.  By  this  method  the  line  is  divi- 
ded into  a  number  of  short  stages,  at  the 
extremity  of  each  of  which  an  engine  is 

S  laced.  The  wagons  or  carriages,  when 
rawn  by  an  engine  to  its  station,  are  de- 
tached, and  connected  with  the  extremity 
of  the  rope-work  by  the  next  stationary 
engine,  and  thus  the  journey  is  performed 
from  station  to  station  by  separate  en- 
gines. By  the  other  method,  each  load 
transported  along  the  line  is  drawn  by  an 


326 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[log 


engine  which  travels  with  it  as  horses 
travel  with  a  carriage  on  a  common  road. 

Until  the  period  to  which  we  now  ad- 
vert, railways  had  been  almost  exclusive- 
ly confined  to  the  transport  of  mineral 
products  from  the  mines  up  to  the  places 
of  shipment,  and  to  this  purpose  exclu- 
sively had  the  locomotive  engine  been 
applied  ;  but  the  ends  to  be  attained  by 
a  railway  of  thirty  miles  in  length,  con- 
necting the  largest  manufacturing  town, 
in  the  greatest  manufacturing  country  in 
the  world,  with  the  greatest,  most  active, 
and  most  opulent  commercial  port,  were 
of  a  nature  so  much  more  extensive  and 
important,  that  it  was  considered  that 
more  than  ordinary  means  should  be  re- 
sorted to  to  obtain  a  moving  power  com- 
mensurate with  the  traffic  which  might 
be  expected  under  such  circumstances. 
Prizes  were  therefore  proposed  to  be 
given,  under  certain  stipulations,  to  those 
who  would  construct  the  most  effective 
locomotive  engines  for  the  purposes  of 
the  road.  This  proposal  produced,  as  was 
anticipated,  much  competition ;  and  the 
spirit  of  emulation  being  roused,  a  trial 
was  appointed,  which  took  place  on  the 
railwav  in  October,  1829.  Engines  of 
several  forms  were  produced ;  and  the 
prize  was  awarded  to  one,  called  the 
JSocket,  constructed  by  Mr.  Robert  Ste- 
venson, the  son  of  Mr.  George  Stevenson, 
the  engineer  of  the  railway.  In  the  first 
trial,  this  engine  attained  the  then  aston- 
ishing speed  of  twenty-nine  miles  an 
hour,  and  when,  unhappily,  at  the  cere- 
mony of  the  opening  ot  the  railway,  the 
accident  occurred  which  deprived  the 
country  of  Mr.  Huskisson,  his  wounded 
body  was  conveyed  by  the  same  engine, 
a  distance  of  abo'ut  fifteen  miles  in  twen- 
ty-five minutes,  being  at  the  rate  of  thirty- 
Bix  miles  an  hour. 

The  circumstances  in  this  mechanical 
arrangement,  on  which  the  rapid  pro- 
duction of  steam  depends,  are  two-fold  : 
first,  the  extensive  surface  exposed  to 
the  radiant  heat  of  the  fire,  by  the  casing 
surrounding  the  fire  box,  and  by  the 
tubes,  twenty-five  in  number  and  only 
three  inches  in  diameter,  by  which  the 
flame  and.  heated  air  are  conducted 
through  the  boiler  from  the  fire  box  to  the 
chimney  ;  and,  secondly,  by  the  power- 
ful draught  maintained  in  the  furnace  by 
the  current  of  steam  constantly  discharged 
up  the  chimney.  It  has  been  mainly  by 
bringing  these  principles  more  fully  into 
operation,  that  all  the  improvements 
since  made  in  the  locomotive  engine  have 
been  effected. 


The  railway  was  not  long  in  operation, 
when  the  arrangement  of  the  tubes  in 
the  boiler  was  improved  ;  their  number 
was  increased  from  twenty-five  to  one 
hundred  and  upwards,  and  their  diame- 
ters diminished  from  three  inches  to  an 
inch  and  a  half.  This  change  alone  pro- 
duced an  increased  efficiency  of  the  fuel, 
the  proportion  of  nearly  two  to  one  ;  the 
consumption  of  coke  in  the  Rocket  hav- 
ing been  very  nearly  2i  pounds  per  ton 
per  mile,  while,  by  the  change  above 
mentioned,  the  consumption  of  fuel  in 
the  new  engines  was  reduced  to  1J  pound 
per  ton  per  mile.  The  position  of  the 
cylinder  was  also  advantageously  changed. 
Instead  of  being  placed,  as  in  the  Rocket, 
outside  the  boiler,  and  exposed  to  the 
cold  air,  through  which  the  engine  passed 
with  such  a  velocity,  they  were  now 
placed  in  that  part  of  the  engine  called 
the  smoke  box,  an  enclosed  space  at  the 
base  of  the  chimney,  into  which  the  flame 
and  heated  air  escaping  from  the  tubes 
passed.  By  this  arrangement  the  cylin- 
ders, were  always  maintained  as  hot  as 
the  air  which  issued  from  the  fines,  and 
all  condensation  of  steam  by  their  ex- 
posure prevented. 

As  the  cylinders  were  now  placed  be- 
tween the  wheels,  their  operation  could 
not  be  effected  in  the  same  manner  as  in 
the  Roeket.  The  connecting  rods  were 
accordingly  made  to  act  on  two  cranks, 
constructed  upon  the  axle  of  the  wheels, 
placed  at  right  angles  to  each  other,  so 
that  one  may  always  be  at  its  dead  point, 
while  the  other  was  in  full  action.  This 
double-cranked  axle  was,  from  the  weak- 
ness consequent  upon  its  form,  liable  at 
first  to  fracture  ;  but  improved  methods 
of  forging  them  subsequently  gave  them 
sufficient  strength,  and  now  the  fracture 
of  a  cranked  axle  rarely  occurs. 

The  two  chief  improvements  in  the  lo- 
comotive engine,  which  succeeded  those 
now  explained,  and  which  brought  that 
machine  to  its  present  state  of  efficiency, 
consisted,  first,  in  the  substitution  of 
brass  for  copper  tubes  ;  and,  secondly, 
in  the  addition  of  another  pair  of  wheels 
to  support  the  engiue.  It  was  found,  by 
continued  experience,  that  the  copper 
tubes,  from  some  peculiar  action  of  the 
fire  upon  them,  which  has  never  been 
explained  or  understood,  were  subject  to 
rapid  decay  ;  and  in  the  year  1838,  after 
an  experience  of  about  three  years  of  the 
working  of  these  engines,  it  occurred  to 
Mr.  Dixon,  then  one  of  the  superintend- 
ents of  the  engineering  department  of 
the  Liverpool  and  Manchester  railway,  to 


LOC] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


327 


try  the  eff  sot  of  "brass  tubes.  The  ex- 
periment was  eminently  successful ;  they 
were  found  to  last  six  or  eight  times  as 
long  as  copper  tubes  of  the  same  dimen- 
sions. Having  now  brought  down  the 
history  of  the  locomotive  engine  to  the 
present  time,  we  shall  give  a  description 
of  one  of  these  machines  in  its  most  im- 
proved form. 

Description  of  the  most  improved  Loco- 
motive Engine  in  operation'm  1840.— A  lon- 
gitudinal Vertical  section  of  a  locomotive 
engine  is  represented  here. 


The  boiler,  as  has  been  explained  in 
the  engines  already  described,  is  a  cylin- 
der placed  upon  its  side  ;  the  fire-box 
consists  of  two  castings  of  metal,  one 
within  the  other,  bolted  together  by  riv- 
ets represented  at  h  ;  the  fire-grate  is 
represented  at  D.  The  fire  door  is  rep- 
resented at  g,  opening  upon  the  platform 
where  the  engineer  stands.  It  will  be 
perceived  in  the  section  that  the  fire-box 
is  on  every  side  surrounded  by  the  water 
contained  between  the  two  casings,  the 
level  of  the  water  in  the  boiler  being 
above  the  roof  of  the  fire-box.  The 
tubes  by  which  the  flame,  and  the  pro- 
ducts of  combustion,  are  drawn  from  the 
fire-box  into  the  smoke-box  are  repre- 
sented at  E.  The  smoke-box,  containing 
the  cylinders  and  the  blast  pipe,  and  sup- 
porting the  chimney,  is  represented  at  F. 
In  the  engine  from  which  the  drawing 
was  taken,  the  boiler  is  a  cylinder  of  7t 
feet  long  and  3i  in  diameter ;  it  is  clothed 
with  a  boarding  of  wood,  represented  at 
a,  and  bound  round  by  iron  hoops  screwed 
together  at  the  bottom.  Wood  being  a 
slow  conductor  of  heat,  this  covering  has 
the  effect  of  keeping  the  boiler  warm,  and 
checking  the  condensation  of  steam. 

As  the  top  of  the  fire-box  would  be 
liable  to  be  destroyed  by  the  action  of  the 
fire,  if  the  level  ot  the  water  in  the  boiler 
were  suffered  to  fall  below  it,  so  as  to  leave 
it  uncovered,  a  leaden  plug  is  inserted 
in  it,  which  would  melt  out  before  the 


copper  would  become  injuriously  heated, 
and  the  steam  rushing  out  at  the  aperture 
would  cause  the  fire  to  be  extinguished. 
The  tubes  E,  which  serve  to  conduct  the 
flame  through  the  boiler  to  the  smoke- 
box,  are  made  of  the  best  rolled  brass, 
l-13th  of  an  inch  thick,  and  If  of  an 
inch  in  external  diameter;  they  are  124 
in  number,  and  the  distance  between  tube 
and  tube  is  three-quarters  of  an  inch.  The 
number  of  these  tubes  is  at  present  sel- 
dom less  than  90,  and  varies  between  that 
and  150.  The  tubes  act  as  stays,  connect- 
ing the  ends  of  the  boiler  to  strengthen 
them ;  but,  besides  these,  there  are 
rods  of  wrought-iron,  which  extend 
from  end  to  end  of  the  boiler,  above 
the  roof  of  the  fire-box.  The  smoke- 
box  F,  containing  the  cylinders,  steam- 
pipe,  and  blast-pipe,  is  4  feet  wide,  and  2 
feet  long ;  it  is  formed  of  wrought-iron 
plates,  rivetted  in  the  same  manner  as 
those  of  the  fire-box.  From  the  top  of 
the  smoke-box,  which,  like  the  fire-box, 
is  semi-cylindrical,  rises  the  chimney  G, 
15  inches  diameter,  made  of  J-inch  iron 

Elates,  rivetted  and  bound  round  by 
oops.  Near  the  bottom  of  the  smoke- 
box  the  working  cylinders  are  placed  side 
by  side,  in  a  horizontal  position,  with  the 
slide  valves  upwards. 

At  the  top  of  the  external  fire-box,  a 
circular  aperture  is  formed  15  inches  in 
diameter;  and  upon  this  aperture  is 
placed  the  steam-dome  T,  2  feet  in  height, 
and  secured  to  the  aperture  by  nuts.  The 
steam-dome  is  made  of  brass,  nearly  half 
an  inch  thick.  A  funnel-shaped  tube  d. 
with  its  wide  end  upwards,  is  flanged 
upon  the  side  of  the  great  steam-pipe  S, 
and  is  carried  upward,  so  that  its  mouth, 
is  near  the  top  of  the  steam-dome  T.  In 
order  to  pass  into  the  steam-pipe  S,  the 
steam  which  fills  the  upper  part  of  the 
boiler  A  must  ascend  the  steam-dome 
and  enter  the  funnel  d,  as  indicated  by 
the  bent  arrow.  This  arrangement  pre- 
vents, in  a  great  degree,  the  effect  of  prim- 
ing, by  which  word  is  expressed,  techni- 
cally, the  spray  of  water  which  rises  from 
the  water  of  the  boiler,  and  is  mixed  with 
the  steam  in  the  upper  part  of  it ;  as  the 
steam  ascends  the  steam-dome,  this  spray 
falls  back,  and  nothing  but  pure  steam 
enters  the  funnel  d.  The  wider  part  of 
the  great  steam-pipe  S  is  flanged,  and 
screwed  at  the  hinder  end  to  a  corrcs- 

Eonding  aperture  in  the  back  of  the  fire- 
ox,  where  the  engineer  stands  ;  this 
opening  is  covered  by  a  circular  plate,  se- 
cured by  screws,  having  a  stuffing-box  in 
its  centre,  of  the  same  kind  as  is  used 


328 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[loc 


for  the  piston  rods  of  steam  cylinders. 
Through  this  stuffing-box  the  spindle  or 
rod  a  of  the  regulator  passes ;  and  to  its 
end  is  attached  a  winch  h,  by  which  the 
spindle  a  is  capable  of  being  turned.  To 
the  other  end  of  this  spindle,  at  <?,  is  at- 
tached a  plate,  which  moves  upon  aper- 
tures formed  in  the  cover  of  the  end  of  the 
great  steam-pipe  S ;  so  that,  by  turning  the 
winch  h  more  or  less,  this  plate  e  may  br 
removed  more  or  less  from  the  openings  ; 
and  thus  the  steam  may  be  allowed  to  in- 
ter the  steam-pipe  from  the  steam-dome 
in  greater  or  less  quantity,  or  may  be  shut 
off  altogether.  The  steam-pipe  S  being  in- 
closed within  the  boiler,  is  maintained  at 
the  same  temperature  as  the  steam  in  the 
boiler  ;  and  therefore  the  steam,  in  pass- 
ing through  it,  is  not  liable  to  condensa- 
tion. The  steam-pipe,  passing  through 
the  tube  plate  at  the  front  of  the  boiler,~is 
turned  down  at  right-angles  in  the  smoke- 
box,  where,  dividing  into  two  branches, 
one  is  conducted  to  each  of  the  valve- 
boxes  of  the  cylinders.  The  lower  ends 
of  these  branches  are  flanged  to  the  valve 
boxes  at  the  ends  of  the  cylinders  nearest 
to  the  boiler  ;  by  these  pipes  the  steam 
is  conducted  into  the  valve-boxes,  or 
steam-chests,  from  which  it  is  admitted 
by  slide-valves  to  the  cylinders  to  work 
the  pistons.  On  the  upper  sides  of  the 
cylinders  are  the  steam-chests  U,  commu- 
nicating Avith  the  passage ;  m,  fig.  5,  lead- 
ing to  the  top  of  the  cylinder,  n  leading  to 
the  bottom,  and  o  leading  through  the 
side-pipe  to  the  P'  blast-pipe.  These 
openings  are  governed  by  a  slide,  so  that, 
when  "steam"  is  admitted  through  m, 
the  communication  shall  be  opened 
between  n  and  o.  Thus,  when  steam 
is  admitted  to  the  top  of  the  cylinder, 
the  steam  from  the  bottom  will  flow 
from  n  through  <?,  into  the  blast-pipe. 
When  the  piston  reaches  the  bottom  of 
the  cylinder,  then  the  slide  opens  a  com- 
munication between  n  and  the  steam- 
pipe,  and  between  m  and  o.  Thus 
steam  will  be  admitted  to  the  bottom 
of  the  cylinder,  while  the  steam  from 
the  top  will  escape  from  m,  through  o 
to  the  blast-pipe.  In  this  way,  by 
the  alternate  shifting  of  the  slide/steam 
is  admitted  alternately  to  each  end  of 
the  cylinder,  and  allowed  to  escape 
from  the  other  end,  and  the  alternate 
motion  of  the  piston  and  the  cylinder 
is  thereby  maintained.  _  The  pistons 
used  in  iocomotive  engines  are  of  tho 
kind  called  metallic  pistons,  and,  from 
their  horizontal  position,  they  have  a  ten- 
dency to  wear  unequally  in  the  cylinders, 


their  weight  pressing  them  on  one  side* 
only;  but  from  their  small  magnitude, 
this  effect  is  found  to  be  imperceptible  in 
practice.  The  cross  pipe  P',  which  com- 
municates with  the  eduction  passage  o,  in 
each  of  the  valve-boxes,  has  an  opening  in 
the  centre,  presented  upward.  To  this 
opening  is  flanged  the  base  of  the  blast  pipe 
jt>,  fig.  4,  which  rises  in  a  direction  slightly 
curved,  and  has  its  mouth  presented  up- 
ward in  the  centre  of  the  chimney  G.  The 
steam  which  is  discharged  at  each  stroke 
of  the  pistons  from  the  cylinders,  passes 
through  this  pipe,  and  escapes  up  the 
chimney  by  puffs.  When  an  engine  is 
moving  slowly,  these  puffs  are  distinctly 
audible,  resembling  the  coughing  of  a 


horse  ;  but  when  at  full  speed,  they  suc- 
ceed each  other  so  rapidly  that  the  ear 
can  scarcely  distinguish  their  intervals. 
It  is  this  stream  of  waste  steam,  continu- 
ally rushing  up  the  chimney,  that  main- 
tains the  necessary  draught  in  the  fire- 
place ;  the  upper  current  thus  produced 
in  the  funnel  causes  a  corresponding  cur- 
rent into  the  smoke-box  F,  through  the 
tubes  E ;  and  there  is  this  excellence  in  the 
arrangement,  that  the  force  of  the  draught 
in  the  chimney  being  proportional  to  the 
quantity  of  steam  produced,  it  must  be 
therefore  proportional  to  the  quantity  of 
fuel  necessary  to  be  consumed. 

The  force  of  the  steam  thus  impressed 
upon  the  pistons  is  communicated  by  tho 
piston  rods  Y,  the  cross  heads  of  which 
move  in  guides  to  the  connecting  rods  B, 
which  are  attached  to  the  crank  pins  of 
the  working  axle  C ;  so  that,  as  the  piston 
rods  are  driven  backwards  and  forwards 
in  the  cylinders,  the  working  axle  is  made 
to  revolve.  As  this  axle  is  the  instrument 
by  which  the  impelling  force  is  conveyed 
to  the  load,  and  as  it  has  to  support  a 
great  portion  of  the  weight  of  the  engine, 
it  is  constructed  with  great  strength  and 
precision.  Its  length  is  6i  feet,  and  its 
diameter  5  inches.  At  the  centre  part  it 
is  cylindrical,  and  is  increased  to  5j 
inches,  where  the  cranks  are  formed. 
The  sides  of  the  cranks  are  four  inches 
thick ;  and  the  crank  pins,  which  are 
truly  cylindrical,  arc  5  inches  in  diameter 
and  3  in  length.  Upon  the  parts  which 
are  7*  inches  long,  the  great  driving 
wheels  D  are  firmly  fastened,  so  as  to  be 
prevented  from  turning  or  shaking  upon 
the  axle.  Brasses  are  fixed  on  the  out- 
side of  the  engine,  which  rest  upon  these 
E  rejections  G  of  the  axle ;  and  upon  these 
rasses  the  weight  of  the  engine  is  sup- 
ported. 
The  strength  and  accuracy  of  construe- 


LOC] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


329 


tion  necessary  for  these  axles  render  them 
expensive  ;  they  cost  almost  $200  each. 
They  are  seldom  broken,  but  sometimes 
bent  when  the  engine  escapes  from  the 
rails. 

The  method  by  which  the  slides  are 
made  to  govern  the  admission  and  escape 
of  the  steam  to  and  from  the  cylinders,  is 
nearly  the  same  as  in  the  steam-engine 
used  for  the  general  purposes  of  manu- 
facture ;  and  for  a  general  description  of 
the  method  see  Steam-Engine.  Mean- 
while it  may  be  here  briefly  stated,  that 
this  is  effected  by  two  circular  plates  call- 
ed eccentrics,  on  the  great  working  axle. 
These  eccentrics  are  circular  plates  or 
rings,  formed  upon  or  attached  to  the  axle 
so  as  to  revolve  in  their  own  plane,  form- 
ing, in  effect,  a  part  of  the  axle  itself ;  but 
they  are  so  placed  that  their  centres  do 
not  coincide  with  the  centre  of  the  axle, 
and,  consequently,  as  they  revolve  with 
the  axle,  their  centres  are  alternately 
thrown  backwards  and  forwards,  as  they 
pass  on  the  one  side  or  the  other  of  the 
axle.  These  circular  plates  are  surround- 
ed by  rings,  within  which  they  revolve, 
but  which  do  not  revolve  with  them. 
These  rings  are  alternately  thrown  back- 
ward and  forward  by  the  play  of  the  ec- 
centrics ;  and  to  these  rings  are  attached 
rods  e  e,  which  communicate  motion  to 
the  arms  which  drive  the  rods  of  the 
slides.  Thus  the  alternate  motions  of 
the  eccentrics  backward  and  forward  pro- 
ceeding from  the  working  axle,  produce 
a  corresponding  backward  and  forward 
motion  in  the  slides,  and  thereby  govern 
the  admission  and  escape  of  the  steam  to 
and  from  the  cylinders.  When  it  is  re- 
quired to  reverse  the  motion  of  the  en- 
gine, or  to  make  it  move  backwards,  the 
motion  of  the  slides,  and  therefore  the' 
positions  of  the  eccentrics  on  the  work- 
ing axle,  must  be  the  contrary  of  that  ne- 
cessary to  produce  a  progressive  motion. 
Sometimes  this  is  effected  by  shifting  the 
position  of  the  eccentrics  on  the  working 
axle ;  but  more  commonly  it  is  effected 
by  a  second  pair  of  eccentrics,  first  placed 
on  the  axle  in  a  position  contrary  to  the 
others.  When  the  engine  is  driven  back- 
ward, the  eccentrics  are  thrown  out  of 
gear,  and  the  other  eccentrics  are  brought 
into  action. 

As  all  the  moving  parts  of  the  engine 
require  to  be  constantly  lubricated  with 
oil,  to  diminish  the  friction  and  keep  them 
cool,  oil  cups  for  this  purpose  are  fixed 
upon  them.  In  some  engines  these  oil 
cups  are  attached  separately  to  all  the  j 
moving  parts  ;  in  others  they  are  placed  | 


near  each  other  in  a  row  on  the  side  of  the 
boiler,  and  communicate  by  small  tubes 
with  the  several  parts  to  be  lubricated. 

The  tender  is  a  carriage  attached  be- 
hind the  engine,  and  close  to  it,  carrying 
coke  for  the  supply  of  the  furnace,  and  a 
tank  containing  water  for  the  boiler.  The 
feed  for  the  boiler  is  conducted  through 
a  curved  pipe  proceeding  from  the  tank 
and  carried  first  downwards,  and  after- 
wards in  a  horizontal  direction,  as  repre- 
sented at  K,  under  the  boiler.  It  com- 
municates with  a  forcing  pump,  which  is 
worked  by  an  arm  driven  by  the  cross 
head  of  the  steam  piston.  By  this  pump 
water  is  constantly  forced  into  the  boiler, 
so  long  as  the  pump  is  kept  in  communi- 
cation with  the  tank  ;  but  this  communi- 
cation may  be  opened  and  cut  off  by  a 
cock  £,  governed  by  the  engineer.  As 
the  feed  of  the  boiler  by  the  introduction 
of  cold  water  checks  the  activity  of  the 
evaporation,  it  is  the  custom  not  to  feed 
the  boiler  regularly  and  constantly,  but 
to  throw  on  the  feed  when  the  work  on 
the  engine  is  light  and  the  consumption 
of  steam  small,  and  to  shut  it  off  when 
much  steam  is  required.  The  circum- 
stances of  a  railway  naturally  suggest  this. 
When  the  engine  is  ascending  an  incline, 
all  the  steam  which  the  boiler  is  capable 
of  producing  is  required,  and  therefore 
the  activity  of  the  boiler  is  stimulated  by 
shutting  off*  the  feed  ;  but  in  descending 
an  incline  less  power  is  required,  and  the 
feed  is  put  on. 

Until  within  the  last  few  years,  loco- 
motive engines  were  supported  on  only 
four  wheels.      It  is  now,  however,  the 

General  practice  to  place  them  on  six,  the 
riving  wheels  being  in  the  middle.  To 
give  greater  security  to  the  position  of 
the  engine  between  the  rails,  it  is  usual 
to  construct  flanges  on  the  tires  of  all  the 
six  wheels.  Mr.  Stevenson,  however, 
has  been  in  the  practice  of  constructing 
the  driving  wheels  without  flanges,  and 
with  tires  truly  cylindrical,  depending  on 
the  flanges  of  the  two  pairs  of  smaller 
wheels  to  maintain  the  engine  between 
the  rails.  The  wheels  of  the  engine  are 
constructed  in  this  manner.  The  driving 
wheels  D  are  fixed  on  the  cranked  axle 
C,  and  are  constructed  with  cylindrical 
tires  without  flanges.  They  are  5  feet  in 
diameter.  The  wheels  L  are  3  feet  6  in. 
in  diameter,  and  have  conical  tires  with 
flanges.  They  are  placed  immediately 
behind  the  smoke-box.  The  wheels  M 
are  precisely  similar  to  L,  and  are  placed 
immediately  behind  the  fire-box. 
When  an  engine  is  required  for  the 


330 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[loo 


transport  of  very  heavy  loads,  such  as 
those  of  merchandise,  the  adhesion  of 
one  pair  of  working  wheels  is  sufficient ; 
and,  in  such  cases,  one  of  the  two  pairs 
of  wheels  L  or  M  is  made  of  the  same  di- 
ameter as  the  driving1  wheels,  and  a  bar 
is  attached  to  points  "on  the  outside  of  the 
wheels,  at  equal  distances  from  their  cen- 
tre, connecting  them  in  such  a  manner 
that  any  force  applied  to  make  one  pair 
of  wheels,  revolve  must  necessarily  im- 
part the  same  motion  to  the  other  pair. 
By  such  means  the  force  of  the  steam  is 
made  to  drive  both  pairs  of  wheels,  and 
consequently  a  proportionally  increased 
adhesion  is  obtained. 

The  speed  which  an  engine  is  capable 
of  imparting  depends  on  the  rate  at  which 
the  pistons'are  capable  of  being  moved  in 
the  cylinders.  By  every  motion  of  each 
piston  backward  and  forward  one  revolu- 
tion of  the  driving-wheel  is  produced ; 
and  by  each  revolution  of  the  driving- 
wheels  supposing  them  not  to  slip  upon 
the  rails,  the  load  is  driven  through  a 
distance  equal  to  their  circumference. 
As  the  two  cylinders  work  together,  it 
follows  that  a  quantity  of  steam  sufficient 
to  fill  four  cylinders  must  be  supplied  by 
the  boiler  to  the  engine,  to  move  the  train 
through  a  distance  equal  to  the  circum- 
ference of  the  driving-wheels  ;  and  in  ac- 
complishing this,  each  piston  must  move 
twice  from  end  to  end  of  the  cylinder, 
each  cylinder  must  be  twice  filled  with 
steam' from  the  boiler,  and  that  steam 
must  be  twice  discharged  from  the  blast- 
pipe  into  the  chimney.  If  the  driving- 
wheels  be  5  feet  in  diameter,  their  cir- 
cumference will  be  15  feet  7  inches.  To 
drive  a  train  with  a  velocity  of  30  miles 
an  hour,  it  is  necessary  that  the  engine 
be  propelled  through  45  feet  per  second  ; 
and  to  accomplish  this  with  4  feet  wheels 
they  must  make  nearly  3  revolutions  per 
second  ;  and  as  each  revolution  requires 
two  motions  of  the  piston  in  the  cylinder, 
it  follows  that  each  piston  must  move 
three  times  forward  and  three  times  back- 
ward in  the  cylinder  in  a  second ;  that 
steam  must  be  admitted  six  times  per 
second  to  each  cylinder,  and  discharged 
12  times  per  second  through  the  blast- 
pipe:  the  motion  of  the  slides  and  other 
reciprocating  parts  of  the  machinery  must 
consequently  correspond. 

This  rapid  reciprocating  motion  being 
injurious  to  the  machinery,  attempts  have 
been  made  to  diminish  it  by  the  adoption 
of  larger  working-wheels,  and  the  driv- 
ing-wheels on  several  of  the  great  lines 
have  been  accordingly  increased  to  51  and 


6  feet  in  diameter.  Such  engines  have  not 
been  yet  sufficiently  long  in  use  to  afford 
a  practical  estimate  of  the  effects  of  this 
change.  Experiments  of  a  much  bolder 
kind  have  been  tried  in  England  on  the 
Great  Western  Railroad,  where  driving- 
wheels  of  10  feet  in  diameter  have  been 
worked.  From  a  course  of  experiments, 
however,  made  by  Dr.  Lardner  with  those 
engines,  it  did  not  appear  that  they  had 
any  advantage  over  those  constructed  with 
smaller  and  lighter  wheels.  Experience 
appears  to  have  since  confirmed  this,  as 
they  are  now  for  the  most  part  abandon- 
ed. The  pressure  of  steam  in  the  boiler 
is  usually  limited  by  two  safety-valves — 
one  represented  at  N,  under  the  control 
of  the  engineer ;  and  the  other  at  O, 
which  cannot  be  approached  by  him.  The 
safety-valve  at  N  is  held  down  by  a  lever 
r,  which  is  attached  to  a  spiral  spring,  and 
which  may,  by  an  adjusting  screw,  be 
made  to  press  on  the  valve  with  any  re- 
quired force.  The  second  valve  0  is  press- 
ed by  several  small  elliptical  springs, 
placed  one  above  another  over  the  valve, 
and  held  down  by  a  screw,  which  turns 
in  a  frame  fixed  into  the  valve  seat.  By 
this  screw  the  pressure  on  the  valve  can 
be  adjusted. 

In  order  to  give  notice  of  the  approach 
of  the  train,  a  steam- whistle  Z  is  placed 
immediately  above  the  fire-box  at  the 
back  of  the  engine.  This  is  an  apparatus 
composed  of  two  small  hemispheres  of 
brass,  separated  one  from  the  other  by  a 
small  space.  Steam  is  made  to  pass 
through  a  hollow  space  formed  in  the 
lower  hemisphere,  and  escapes  from  a 
very  narrow  circular  opening  round  the 
edge  of  that  hemisphere.  The  edge  of 
the  upper  hemisphere  presented  down- 
wards encounters  this  steam,  and  an  effect 
is  produced  similar  to  the  action  of  air  in 
organ  pipes.  A  shrill  whistle  is  produced, 
which  can  be  heard  at  a  great  distance, 
and  differing  from  all  ordinary  sounds, 
never  fails  to  give  notice  of  the  approach 
of  a  train. 

It  is  not  usual  to  express  the  power  of 
locomotives,  in  the  same  manner  as  that 
of  other  engines,  by  the  term  horse  power. 
Indeed,  until  the  actual  amount  of  resist- 
ance encountered  by  these  machines 
shall  be  more  certainly  ascertained,  it  is 
impossible  that  their  efficiency  can  be  es- 
timated. The  quantity  of  water  evapo- 
rated supplies  a  major  limit  to  the  power 
exerted  ;  but  even  this  necessary  element 
is  not  ascertained.  Mr.  Stevenson  states 
that  an  engine  such  as  that  above  de- 
scribed is  capable  of  evaporating  only  77 


LOC] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


331 


cubic  feet  of  -water  per  hour ;  but  Dr. 
Lardner  found  that  the  mean  evaporation 
obtained  by  a  very  accurately  conducted 
experiment  over  200  miles  of  railway, 
with  an  engine  called  the  "Hecla,"  simi- 
lar to  the  above,  was  90  cubic  feet  per 
hour  very  nearly. 

Bat  a  still  greater  evaporating  power 
than  this  is  found  among  the  large  en- 
gines working  on  the  Great  Western  Kail- 
way.  In  an  experiment  made  by  Dr. 
Lardner  with  the  "  North  Star,"  drawing 
HOi  tons  gross,  at  30i  miles  an  hour,  the 
evaporation  was  200  cubic  feet  an  hour. 

On  the  evaporating  power  of  the  en- 
gines, other  things  being  the  same,  must 
ultimately  depend  the  speed  of  railway 
traffic.  For  it  must  be  apparent  that  no 
modification  which  can  be  made  in  the 
mechanism  of  the  engine,  no  change  in 
the  magnitude  of  the  driving-wheels,  nor 
any  other  expedient  of  the  same  kind,  can 
add  any  thing  to  the  real  working  power 
of  the  machine.  Mechanism  is  the  means 
by  which  power  is  modified  and  conveyed 
to  the  working  points,  not  the  agent  by 
which  it  is  produced.  The  real  and  the 
only  source  of  power  in  the  steam-engine 
is  to  be  found  in  the  phenomena  which 
are  evolved  in  the  conversion  of  water 
into  vapor  (for  an  account  of  which  phe- 
nomena see  Steam)  ;  and  therefore  the 
limit  of  railway  speed  must  always  depend 
on  the  rate  at  which  the  locomotive  boiler 
is  capable  of  evaporating  water.  The  ex- 
periments above  explained  show  the  ac- 
tual evaporating  powers  possessed  by  the 
boilers  now  in  use,  and  every  addition  to 
such  evaporating  power  will  produce  a  cor- 
responding, though  not  a  proportionate, 
augmentation  of  the  speed  of  railway 
trains. 

Nothing  can  be  more  absurdly  exag- 
gerated than  the  accounts  which  have 
been  put  in  circulation  of  the  speed  at- 
tained on  railways.  No  reliance  whatever 
can  or  ought  to  be  placed  on  such  reports, 
unless  they  are  attested  by  competent 
persons  accustomed  to  that  kind  of  in- 
quiry, and  who  have  been  themselves 
witnesses  of  them.  In  the  extensive 
courses  of  experiments  which ,  for  several 
years  back,  have  been  conducted  by  Dr. 
Lardner,  he  has  never  in  any  instance, 
even  with  an  unloaded  engine,  exceeded 
a  speed  of  45  miles  an  hour ;  nor  was  that 
speed  ever  maintained  for  any  considera- 
ble distance.  With  the  best  and  most 
powerful  engines  on  the  Great  Western 
Railway  at  their  disposal,  Mr.  Nicholas 
Wood  and  Dr.  Lardner  were  unable  to 
attain  a  spted  in  their  experiments  ex- 


ceeding 45  miles  an  hour.  The  question, 
however,  of  most  interest  to  the  publio 
is,  not  the  speed  which  can  be  obtained 
in  experiments  for  short  distances,  with 
engines  put  into  racing  order,  but  the 
average  speed  which  can  be  maintained 
in  the  general  working  of  a  road.  The 
returns  of  the  railway  companies,  so  far 
as  they  have  been  made  public,  do  not 
supply  the  means  of  determining  this ; 
but  it  is  known  that  the  first  class  trains 
between  London  and  Birmingham,  a  dis- 
tance of  112  miles,  could  not  until  within 
the  last  few  years  make  the  journey,  under 
ordinary  circumstances,  in  less  than  5i 
hours ;  this  would  give  an  average  speed, 
including  stoppages,  of  20  miles  an  hour. 
On  the  Grand  Junction  line  between  Li- 
verpool andBirmingham,  the  journey,  in- 
cluding stoppages,  was  usually  made  in  4\ 
hours,  and  the  distance  is  97  miles  ;  this 
again  is  at  the  rate  of  about  20  miles  an 
hour. 

The  quickest  journey  on  record  was 
made  August  28-,  1848,  on  the  Great 
Western  Railway,  England,  by  the  "  Cou- 
rier" locomotive,  which  ran  with  an  ex- 
press train  weighing  60  tons,  from  Did- 
cot  to  Paddington,  a  distance  of  53  miles, 
in  49  minutes  13  seconds,  or  at  the  rate 
of  67  miles  an  hour.  The  average  speed 
on  railways,  in  this  country,  varies  from 
25  to  33  miles  per  hour. 

A  new  engine  has  been  placed  upon 
the  Boston  &  Worcester  Railroad,  manu- 
factured by  Mr.  Ross  Winans,  of  Balti- 
more, which  has  some  peculiarities  about 
it.  It  is  made  for  burning  anthracite 
coal,  and  has  a  fire-box  6  feet  in  length, 
Si  in  width,  and  about  2  feet  in  depth, 
which  will  contain  at  least  a  ton  of  coal. 
The  fire  grate  is  composed  of  stout,  se- 

Sarate  bars,  so  arranged  as  to  permit  the 
remen  to  turn  them  and  shake  out  the 
ashes,  even  when  the  doors  of  the  fire- 
box are  closed. 

It  is  28  tons  weight,  with  two  driving- 
wheels,  7  feet  in  diameter,  and  8  sup- 
porting or  truck-wheels — the  driving- 
wheels  being  in  the  centre.  It  is  made 
so  that  the  adhesive  power  or  weigh  c 
may  be  thrown  upon  the  driving-wheels, 
for  the  purpose  of  ascending  steep  grades, 
and  thus  adhesive  power  can  be  concen- 
trated or  spread  over  the  whole  of  the 
wheels,  according  as  it  is  needed.  We 
understand  that  for  a  short  distance  it 
attained  the  speed  of  60  miles  per  hour. 
LOCOMOTIVE  POWER,  in  contra- 
distinction to  stationary  power,  is  any 
kind  of  moving  power  applied  to  the 
transport  of  loads  on  land  which  travels 


332 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[loo 


with  the  load  which  it  draws.  Horses 
employed  to  draw  carriages  or  carry  loads 
are  locomotive  powers. 

LOG.  A  machine  used  to  measure  the 
rate  of  a  ship's  velocity  through  the  water. 
It  is  a  piece  of  thin"  board, 'forming  the 
quadrant  of  a  circle  of  about  six  inches 
radius,  and  balanced  by  a  small  plate  of 
lead,  nailed  on  the  circular  part,  so  as  to 
swim  perpendicularly  in  the  water,  with 
the  greater  part  immersed.  The  log-line 
is  fastened  to  the  log  by  means  of  two 
legs,  one  of  which  is  knotted,  through  a 
hole  at  one  corner,  while  the  other  is 
attached  to  a  pin,  fixed  in  a  hole  at  the 
other  corner,  so  as  to  draw  out  occasion- 
ally. The  log-line,  being  divided  into 
certain  spaces,  which  are  in  proportion  to 
an  equal  number  of  geographical  miles, 
as  a  half  or  quarter  minute  is  to  an  hour 
of  time,  is  wound  about  a  reel.  The 
whole  is  employed  to  measure  the  ship's 
headway,  in  the  following  manner : — 
The  reel  being  held  by  one  man,  and  the 
half-minute  glass  by  another,  the  mate  of 
the  watch  fixes  the  pin,  and  throws  the 
log  over  the  stern,  which,  swimming  per- 
pendicularly, feels  an  immediate  resist- 
ance, and  is  considered  as  fixed,  the  line 
being  slackened  over  the  stern,  to  pre- 
vent the  pin  coming  out.  The  knots  are 
measured  from  a  mark  on  the  line,  at  the 
distance  of  12  or  15  fathoms  from  the  log. 
The  glass  is,  therefore,  turned  at  the  in- 
stant that  the  mark  passes  over  the  stern ; 
and,  as  soon  as  the  sand  in  the  glass  has 
run  out,  the  line  is  stopped.  If  the  glass 
runs  30  seconds,  the  distance  between 
the  knots  should  be  50  feet.  When  it 
runs  more  or  less,  it  should,  therefore,  be 
corrected  by  the  following  analogy  :  As 
30  is  to  50,  so  is  the  number  of  seconds 
of  the  glass  to  the  distance  between  the 
knots  upon  the  line. 

LOG-BO AED.  Two  boards  shutting 
together  like  a  book,  and  divided  into 
several  columns,  containing  the  hours  of 
the  day  and  night,  the  direction  of  the 
winds,  and  the  course  of  the  ship,  with 
all  the  material  occurrences  that  happen 
during  the  24  hours,  or  from  noon  to 
noon,  together  with  the  latitude  by  obser- 
vation. From  this  table,  the  officers  work 
the  ship's  way,  and  compile  their  journals. 

LOG-BOO*K,  is  a  book  into  which  the 
contents  of  the  log-board  is  daily  tran- 
scribed at  noon,  together  with  every  cir- 
cumstance, deserving  notice,  that  may 
happen  to  the  ship,  or  within  her  cog- 
nizance, either  at  sea  or  in  a  harbor,  &c. 
The  intermediate  divisions  or  watches  of 
a  log-book  contain  four  hours  each. 


LODE,  is  the  name  given  by  the  Corn- 
ish miners  to  a  vein,  whether  it  be  filled 
with  metallic  or  earthy  matter. 

LOGWOOD,  is  the  wood  of  the  Hcema- 
toxylon  Campechianum,  a  native  tree  of 
Central  America,  grown  in  Jamaica  since 
1715.  It  was  first  introduced  into  Eng- 
land in  the  reign  of  Elizabeth,  but  as  it 
afforded  to  the  unskilful  dyers  of  her 
time  a  fugitive  color,  it  was  not  only  pro- 
hibited from  being  used,  under  severe 
penalties,  but  was  ordered  to  be  burned 
wherever  found,  by  a  law  passed  in  the 
23d  year  of  her  reign.  The  same  preju- 
dice existed,  and  the  same  law  was  en- 
acted against  indigo.  At  length,  after  a 
century  of  absurd  prohibition,  these  two 
most  valuable  tinctorial  matters,  by  which 
all  our  hats,  and  the  greater  part  of  our 
woollen  cloths,  are  dyed,  were  allowed  to 
be  used. 

Old  wood,  with  black  bark  and  with 
little  of  the  white  alburnum,  is  preferred. 
Logwood  is  denser  than  water,  very 
hard,  of  a  fine  compact  grain,  and  almost 
indestructible  by  the  atmospheric  ele- 
ments ;  it  has  a  sweet  and  astringent 
taste,  and  a  peculiar  not  inoffensive  smell. 

When  chipped  logwood  is  for  some 
time  exposed  to  the  air,  it  loses  a  portion 
of  its  dying  power.  Its  decoction  absorbs 
the  oxygen  of  the  atmosphere,  and  then 
acquires  the  property  of  precipitating 
with  gelatine,  which  it  had  not  before. 
The  dry  extract  of  logwood,  made  frorr. 
an  old  decoction,  affords  only  a  fugitive 
color.  Alcohol  extracts  most  of  the  active 
principles  of  this  wood,  and  forms  it  deep 
colored  tincture.  The  tincture  of  the  fresh 
wood  is  an  excellent  test  for  the  presence 
of  bicarbonate  of  lime  in  mineral  waters, 
with  which  it  produced  a  well  marked 
violet  colored  solution. 

LOOMS,  are  machines  for  crossing  and 
weaving  threads.  The  two  materials  are 
the  warp  and  the  weft,  crossed  and  matted 
by  a  sh uttle  carrying  the  weft.  There  are 
various  forms  for  different  fabrics  and  ma- 
terials, and  next  to  the  plough  the  loom 
is  the  most  useful  of  machines.  Until  a 
few  years  they  were  uniformly  worked  by 
hand. 

The  power  loom  has  now,  however,  for 
most  descriptions  of  weaving,  almost  en- 
tirely superseded  the  baud  loom. 

The  principal  working  parts  are  sub- 
stantially tins  same  in  the  power  loom,  as 
In  the  hand  loom.  The  only  material 
difference  being,  that  in  the  hand  loom, 
the  parts  have  all  their  movements  given 
by  the  hands  and  feet  of  the  weaver,  while 
ill  the  power  loom,  they  all  receive  the 
necessary  motion  from  a'  revolving  shaft. 


mac] 


CYCLOPEDIA    OF  THE    USEFUL    ARTS. 


333 


The  warp  threads,  or  the  threads 
which  run  lengthwise  in  the  cloth,  are 
led  from  a  roller,  termed  the  yarn  beam. 
through  what  is  termed  a  reed.  The  reed 
consists  of  a  number  of  parallel  wires, 
secured  in  a  frame,  which  is  supported  in 
a  swinging  or  vibrating  carriage,  termed 
the  lay.  The  wires  of  the  reed,  serve  to 
keep  the  warp  threads  apart,  and  to  beat 
up  the  weft,  (afterwards  described).  From 
the  reed, the  warp  passes  over  a  bar  termed 
the  breast  beam,  to  a  roller,  termed  the 
cloth  beam.  All  that  part  of  the  warp, 
between  the  yarn  beam  and  the  breast 
beam,  is  kept  straight,  except  while  the 
warp  is  being  filled  in.  The  weft  is  carried 
by  the  shuttle,  which  consists  of  a  piece 
of  wood,  pointed  at  each  end,  and  hol- 
lowed out  in  the  middle  to  receive  a  reel, 
termed  the  bobbin.  The  thread  is  wound 
around  the  bobbin,  and  passed  through  a 
hole  in  one  side  of  the  shuttle,  in  weav- 
ing figured  goods,  where  different  colors 
are  displayed,  a  number  of  shuttle*  are 
employed,  corresponding  to  the  number 
of  colors.  In  order  to  throw  the  shuttle 
or  pass  it,  with  the  weft,  through  the 
warp,  it  is  necessary  to  raise  some  of  the 
warp  threads,  and  depress  others  ;  this  is 
termed  opening  the  shed,  and  is  per- 
formed by  the  harness.  The  harness  con- 
sists of  boards  or  frames  having  looped 
cords  attached,  termed  heddles.  The 
warp  passes  through  the  heddles,  and  by 
raising  and  lowering  the  harness,  the 
sheds  are  opened.  In  the  hand  loom,  the 
harness  is  operated  by  treadles,  worked 
by  the  pressure  of  the'weavers'  feet,  but 
in  power  looms,  it  is  operated  by  various 
means.  In  the  hand  loom,  the  shuttle  is 
passed  through  the  warp  by  hand  ;  but 
in  the  power  loom,  it  rests  upon  a  path  in 
front  of  the  reed,  and  is  thrown  be  me- 
chanical means.  The  thread  unwinds 
from  the  bobbin,  and  remains  in  the  warp, 
and  the  lay,  receiving  a  movement  after 
every  throw  of  the  shuttle,  causes  the  reed 
to  strike  up  all  the  threads  of  the  weft, 
close  together,  and  lay  them  even.  By  the 
continued  opening  and  closing  of  the 
sheds  of  the  warp,  filling  in,  and  striking 
up  of  the  weft,  the  threads  are  interlaced 
closely  together.  The  cloth  beam,  and 
yarn  beam,  each  receive  a  slight  motion 
after  every  filling  of  the  weft.  These  are 
governed  by  take  up  and  let  off,  motions. 
"For  more  information,  see  WEAVING. 
m  LUBRICATION.  The  oiling  of  the 
joints  and  bearings  of  machinery  to  di- 
minish friction.  Resin,  oil,  and  lard  oil 
are  substances  which  form  the  basis  of 
the  best  lubricators.     The  best  instru- 


ment (there  are  many  forms)  for  using 
these  lubricating  liquids,  is  a  tin  cup  with 
a  tube  passing  downwards  from  its  bot- 
tom, through  which  a  cotton  wick  runs. 
The  oil  streams  along  this  in  a  current 
suitable  for  application. 

LUTES  are  pasty,  or  loamy  and  fatty 
matters,  used  to  keep  the  joints  of  chem- 
ical and  other  apparatus  subjected  to  heat 
tight.  They  differ  according  to  the  na- 
ture of  the  vessel  and  operation.  Linseed 
meal  made  into  a  paste  with  water,  closes 
very  well  the  joinings  of  glass  vessels. 
Milk,  lime-water,  and  solution  of  glue, 
make  this  a  better  cement. 

Glue,  lime,  and  white  of  egg,  mixed  to- 
gether, form  a  good  cement  for  china  and 
stoneware. 

Cheese  and  lime  also  form  a  lute  for 
similar  purposes. 

Linseed,  pipe-clay,  and  melted  caout- 
chouc form  a  good  lute  for  acid  vapors, 
and  is  always  soft. 

Fresh  fire-clay  and  ground  fire-bricks 
mixed  together,  form  a  cement  for  cruci- 
bles which  have  to  stand  a  high  degree 
of  heat.  Willis  lute  is  1  oz.  of  borax  in  a 
pint  of  hot  water,  with  slaked  lime  for  a 

Saste  :  to  be  spread  with  a  brush,  with  a 
nish  of  slaked  lime  and  linseed  oil.  Iron 
lute  is  1  part  of  sulphur,  2  of  sal-ammo- 
niac, and  80  of  iron,  rammed  into  joints. 
Cup  cement  is  5  parts  of  resin,  1  of  bees- 
wax, 1  of  red  ochre.  Soft  cement  is  yel- 
low wax  and  one  half  of  turpentine,  with 
Venetian  red.  The  most  common  luting 
is  made  by  rubbing  in  a  mortar  fine  clay 
and  linsee'd  oil,  for  heat;  or  one  of  pipe- 
clay and  three  of  fine  sand  well  kneaded  : 
beeswax  melted  with  one  eighth  of  tur- 
pentine does  for  cold  operations.  Glass 
vessels  which  are  truly  ground  can  do 
without  luting,  and  may  be  covered  with 
thin  leather  or  sheet  caoutchouc  which  is 
impermeable  and  scarcely  acted  upon  by 
vapors. 

LYCOPODIUM  or  Puff  Ball.  A  cryp- 
togamous  plant,  whose  seeds  ripen  m 
September :  they  are  used  in  theatres  to 


imitate  flashes  of  lightning,  by  being 
thrown  across  the  flame  of  a  candle,  when 
they  burst  and  scintillate. 

MACARONI  is  a  dough  made  of  the 
flour  of  superfine  wheat  made  into  a  pipe 
form,  as  thick  as  a  goose-quill.  It  was 
first  prepared  in  Italy,  and  introduced 
into  commerce  under  the  name  of  Geno- 
ese paste.  The  wheat  is  ground  into  a 
coarse  flour,  called  gruan  or  semoule  by 
the  French,  under  light  millstones  placed, 
somewhat  apart.  The  dough  is  made 
from  this  semoule.     See  Vekmicelli. 


334 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mac 


MACE  is  the  arillus  or  thick  tough 
covering  of  the  shell  of  the  fruit  of  the 
nutmeg  (myri-stica  moschata).  It  is  of  a 
brown  or  orange  color.  It  is  first  dipped 
in  brine,  and  then  sun-dried.  It  has  a 
more  agreeable  flavor  than  nutmeg,  and 
has  -a  pungent  taste.  It  contains  two 
kinds  of  oil,  one  unctuous,  bland  and 
thick ;  the  other  aromatic  and  volatile. 
The  oil  is  used  in  medicine,  and  the 
membrane  itself  in  cookery. 

MACERATION  is  the  pouring  on  of  a 
quantity  of  eold  water  upon  a  substance, 
and  leaving  it  to  stand.  The  temperature 
does  not  exceed  65°  Fahr. 

Maceration  is  immersion  in  cold  water 
or  spirits.  Digestion  in  hot.  Infusion  is 
in  hot  liquid.  Decoction  is  continued 
heat  or  boiling.  Extract  is  the  evapora- 
tion of  the  water  from  an  infusion  or  de- 
coction. 

MACHINE,  i)i  a  general  sense,  signi- 
fies any  thing  which  serves  to  increase  or 
regulate  the  effect  of  a  given  force.  Ma- 
chines are  either  simple  or  compound. 
The  simple  machines,  otherwise  called 
the  simple  mechanical  powers,  are  usually 
leckoned  six  in  number;  namely,  the 
lever,  the  wheel  and  axle,  the  pulky,  the 
wedge,  the  screw,  and  the  funicular  ma- 
chine.   See  the  respective  terms. 

Compound  macnines  are  formed  by 
combining  two  or  more  simple  machines. 
They  are  classed  under  different  denom- 
inations, according  to  forces  by  which 
they  are  put  in  motion,  as  hydraulic  ma- 
chines,  pneumatic  machines,  electrical  ma- 
chines, &c. ;  or  the  purposes  they  are  in- 
tended to  serve,  as  military  machines,  ar- 
chitectural machines,  &c. 

Although  there  are  no  limits  to  the 
combination  and  adaptations  of  machin- 
ery, there  are  certain  general  principles 
which  may  be  applied  in  estimating  the 
effects  of  any  machine  whatever.  When 
a  machine  attains  its  state  of  uniform  mo- 
tion, the  momentum  of  the  power  is 
equal  to  that  of  the  resistance,  and  is  the 
same  that  would  be  in  equilibrio  with  the 
resistance  if  there  were  no  motion  at  all. 
From  this  principle,  and  from  the  consi- 
deration that  in  all  machines  the  work 
done  is  to  be  estimated  not  merely  from 
the  quantity  of  resistance  which  is  over- 
come, but  from  the  quantity  overcome  in 
a  given  time,  we  can  ascertain  the  relation 
that  ought  to  subsist  between  the  velo- 
city and  the  load  or  resistance,  in  order 
that  the  effect  of  the  machine  may  be  a 
maximum.  This  maximum  effect  is  pro- 
duced when  the  two  following  conditions 
are  fulfilled:  1.  When  the  load  or  resist- 


ance is  about  four  ninths  of  that  which 
the  power,  when  fully  exerted,  is  just 
able  to  balance,  or  that  which  would  keep 
the  machine  at  rest  altogether;  and,  2, 
when  the  velocity  of  that  part  of  the  ma- 
chine to  which  the  power  is  applied  is 
one  third  of  the  greatest  velocity  of  the 
power.  These  conditions  are  deduced 
from  the  following  empirical  expression, 
which  is  adopted  by  Euler  and  other 
writers  to  represent  the  law  of  the  mov- 
ing power :  Let  P=the  power  applied  (or 
weight  which  the  power,  when  fully  ex- 
erted, is  just  able  to  overcome) ;  R=the 
resistance,  or  load,  or  weight  to  be  over- 
come ;  c  the  greatest  velocity,  or  that  at 
which  the  power  ceases  to  act ;  *-=any 
other  velocity :  then  the  law  of  the  mov- 
ing power  is 

e=p(1-|) 

the  variables  in  this  expression  are  R  and 
v,  and  the  effect  is  represented  by  the 
product  ~Rv;  on  making  which  a  maxi- 
mum, the  rules  of  the  differential  calcu- 
lus give  v=\  c  ;  whence  the  formula  be- 
comes R=4-9ths  P. 

From  these  expressions  it  follows,  that 
when  the  moving  power  and  the  resist- 
ance are  both  given,  if  a  machine  be  so 
constructed  that  the  velocity  of  the  part 
to  which  the  power  is  applied  is  to  the 
velocity  of  the  part  to  which  the  resist- 
ance is  applied  in  the  ratio  of  9  R  to  4  P, 
the  effect  of  the  machine  will  be  a  maxi- 
mum, or  it  will  work  to  the  greatest  pos- 
sible advantage.  The  above  conditions 
apply  equally  to  machines  impelled  by 
animal  force  and  the  agents  of  nature,  as 
running  water,  steam,  the  force  of  gravi- 
ty, &c.  An  animal  exerts  itself  to  the 
greatest  advantage,  or  performs  the  great- 
est quantity  of  work  in  the  least  time, 
when  it  moves  with  about  one  third  of 
the  utmost  speed  with  which  it  is  capable 
of  moving,  and  is  loaded  with  four  ninths 
of  the  greatest  load  which  it  is  capable  of 
putting  in  motion.  It  has  been  supposed 
in  the  above  remarks  that  the  friction  of 
I  the  parts  of  the  machine  is  included  in 
the  resistance. 

MACHINERY.  The  utility  of  machin- 
ery consists  in  the  addition  which  it 
makes  to  human  power.  The  forces  de- 
rived from  wind,  water,  and  steam,  are 
so  many  additions  to  human  power,  and 
the  total  inanimate  force  thus  obtained 
in  Great  Britain  has  been  calculated  by 
Dupin  to  be  equal  te  20,000,000  laborers. 
Instead  of  working  himself,  man  makes 
nature  work  for  him,  and,  in  that  degree, 
ought  to  be  enabled  to  live  as  well,  and 


MACj 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


335 


work  less  himself.  The  effect  ought,  in 
this  respect,  to  ease  the  whole  commu- 
nity, or  it  ceases  to  be  an  advantage.  On 
the  contrivance  of  every  new  tool,  human 
labor  is  abridged.  The  man  who  con- 
trived rollers  quinl  ipled  his  power  over 
brute  matter.  A  t  ool  is  usually  a  more 
simple  machine,  and  generally  used  by 
the  hand;  a  machine  is  a  complex  tool,  a 
collection  of  tools,  and  frequently  put  in 
action  by  inanimate  force.  All  machines 
are  intended  either  to  produce  power,  or 
merely  to  transmit  power  and  execute 
work.  All  the  mechanical  powers  are,  in 
effect,  levers. 

In  the  wheel  and  axle,  the  wheel  is  the 
long  arm,  the  axle  the  short  arm,  and 
their  ratio  or  division  is  the  power. 

In  the  pulley,  one  gives  no  power,  but 
two  gives  double  the  velocity  of  the 
power;  three  treble,  and  so  on,  exactly 
on  the  lever  principle. 

The  inclined  plane  operates  as  a  lever, 
because  the  distance  moved  on  the  plane 
is  greater  than  the  height  gained;  hence, 
the  power  is  as  the  length  of  the  plane  to 
the  height. 

The  wedge  is  another  lever,  on  the  same 
principle  as  the  inclined  plane,  but  varied 
in  power  by  resistance. 

The  screw  is  a  lever  in  which  the  power 
moves  through  the  entire  circumference, 
while  the  obstacle  moves  only  through 
the  distance  of  the  threads. 

Friction  diminishes  the  results,  but,  in 
general,  a  fourth  or  fifth  more  power  is 
applied  than  the  calculation  demands,  to 
compensate  for  friction,  and  other  causes 
of  loss  of  power. 

When  two  bodies  balance  each  other 
by  means  of  any  machine,  and  are  then 
made  to  move,  the  product  of  each  into 
its  velocity,  i.  e.  the  quantities  of  motion 
or  momentum  ascending  or  descending 
perpendicularly  will  be  equal. 

The  quantity  of  power  in  motion  is  the 
velocity  multiplied  into  the  quantity  of 
matter  or  number  of  atoms.  Thus,  a 
cubic  inch  of  lead,  moving  1  yard  per 
second,  has  a  momentum  of  1 ;  and  2 
cubic  inches  a  momentum  of  2 ;  or  1, 
moved  2  yards,  a  momentum  of  2.  But 
a  cubic  inch  of  stone,  but  half  the  density 
of  lead,  would,  in  yard  per  second,  have 
but  half  the  momentum  of  the  lead,  and 
two  cubic  inches  of  such  stone  must 
move  twice  as  fast  as  the  lead,  to  have 
the  same  force  or  momentum. 

Hence,  universally,  velocity,  bulk,  and 
density,  must  be  multiplied  together  for 
momentum ;  and,  if  we  diminish  one, 
we  must  increase  one  of  the  two  others, 


or  both,  to  have  the  same  momentum. 
Animal,  or  other  force,  often  stands  for 
bulk  and  density,  and  then  these  must 
be  varied  as  velocity. 

As  we  increase  velocity,  with  the  same 
power  we  increase  momentum  ;  and,  as 
we  decrease  velocity,  we  must  increase 
power,  to  get  an  equal  momentum. 

This  is  the  foundation  of  all  mechanical 
science  and  practice,  however  varied  or 
complicated  ;  and  this  principle  being  un- 
derstood, we  may,  by  the  aid  of  common 
arithmetic,  be  able  to  pursue  every  use- 
ful mechanical  object. 

It  sometimes  happens,  as  in  chemistry, 
that  the  power  is  invisible  ;  but,  in  these 
cases,  if  there  is  power,  it  is  not  the  less 
matter  and  motion.  Invisible  atoms  are 
concentrating,  or  are  dispersing,  or  are 
moving  one  among  another  in  such  cases. 
We  often  understand  their  action,  and 
sometimes  do  not ;  but  our  ignorance,  in 
particular  cases,  creates  no  alteration  in 
the  general  laws  of  nature. 

To  determine  the  relative  velocity  of  a 
body  moving  in  any  angle  from  the  direc- 
tion of  the  moving  force,  multiply  the 
velocity  conferred  by  the  moving  force  by 
the  natural  cosine  of  the  angle,  and  the 
product  is  the  velocity  in  the  angular  di- 
rection. And,  to  fincl  the  perpendicular 
distance  of  the  two  lines,  multiply  the 
angular  velocity  by  the  sine  of  the  angu- 
lar deflection,  and  the  product  is  that 
distance.  The  relative  lengths  of  the  three 
lines  is  the  measure  of  the  force  in  each. 
In  cases  of  double  or  more  forces,  if 
lines  are  drawn  from  one  another  to  rep- 
resent all  the  forces  at  their  angles,  the 
resultant  force  is  the  line  which  completes 
i  the  figure. 

When  the  work  to  be  done  requires 

I  more  force  for  its  execution  than  can  be 

!  generated  in  the  time  necessary  for  its 

!  completion,  recourse  must  be  had  to  a 

I  fly-wheel,   which  is   a  wheel   having  a 

j  heavy  rim,  so  that  the  greater  part  of  the 

j  weight  is  near  the  circumference.     An- 

I  other  method  consists  in  raising  a  weight, 

i  and  then  allowing  it  to  fall.    And  another 

I  in   condensing  air,  by  great  force,  and 

then  using  its  expansive  force  as  required. 

Uniformity  in  the  motion  of  machinery 

is  essential.    The  governor,  in  the  steam- 

engine,  and  a  vane  or  fly  of  little  weight, 

but  large  surface,  which  revolves  rapidly, 

and  soon  acquires  a  uniform  rate  by  the 

resistance  of  the  air,  are  contrivances  for 

steadying  power. 

Increase  of  velocity  is  effected  by  a  band, 
passing  round  a  large  wheel,  and  then 
round  a  small  spindle. 


336 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mad 


Diminution,  of  velocity  is  effected  by 
systems  of  pulleys,  or  by  transmission 
through  a  number  of  wheels. 

Spreading  the  action  of  a  force  exerted 
for  a  few  minutes  over  a  large  time,  is  one 
of  the  most  useful  employments  of  ma- 
chinery, and  the  half  minute  which  we 
spend  in  winding  up  a  watch,  is  an  ex- 
ertion of  force  which,  by  the  aid  of  a  few 
wlieeU,  is  spread  over  24  hours. 

Machinery  affords  a  sure  means  of  rem- 
edying the  inattention  of  human  agents, 
by  instruments  ;  for  instance,  for  count- 
ing the  strokes  of  an  engine,  or  the  num- 
ber of  coins  struck  in  a  press.  The  tell- 
tale, apiece  of  mechanism  connected  with 
a  clock,  in  an  apartment  to  which  a  watch- 
man has  not  access,  reveals  whether  he 
has  neglected,  at  any  hour,  to  pull  a  string 
in  token  of  his  vigilance. 

The  precision  with  which  all  operations 
are  executed  by  machinery,  and  the  exact 
similarity^  of  the  articles  made,  produce 
economy  in  the  consumption  of  all  raw 
materials. 

The  accuracy  with  which  machinery 
executes  its  work  is,  perhaps,  one  of  its 
most  important  advantages.     It  would 
hardly  be  possible  for  a  very  skilful  work-  j 
man,  with  files  and  polishing  substances,  | 
to  form  a  perfect  cylinder  out  of  a  piece  j 
of  steel ;  but  this  process,  by  the  aid  of 
the  lathe  and  the  sliding-rest,  is  the  every- 
dav  employment  of  hundreds  of  workmen. 

The  objections  to  machinery  arise  from 
the  faulty  distribution  of  its  benefits  to 
society,  and  the  neglect  and  injustice  of 
not  fairly  indemnifying  those  whose  skill 
and  capital  is  destroyed  by  new  inventions. 

Machinery  is,  therefore,  in  the  produc- 
tion of  cheap  manufactures  for  exporta- 
tion, and  even  for  home  consumption,  to 
be  regarded  as  a  public  benefit.  But 
there  are  two  parties,  in  regard  to  the  ad- 
vantages and  disadvantages  of  machinery. 
The  political  economists,  who  consider 
society  in  the  abstract,  and  look  to  gene- 
ral results,  are  partisans  of  all  means 
which  produce  at  the  least  cost,  and,  there- 
fore, or  machinery.  So,  also,  inventors,  or 
their  assignees,  who  manufacture  cheap, 
and,  for  a  time,  sell  at  the  established 
price,  or  with  such  small  abatement  of 
the  manual  price  as  secures  the  market, 
thereby  making  vast  profits.  But  the 
working  artisan,  who,  by  a  machine,  is 
thrown  out  of  an  employment  by  which 
he  and  his  forefathers  have  long  subsist- 
ed, and  other  manufacturers,  who  find 
themselves  undersold  and  their  trade  de- 
stroyed, are  enemies  of  all  new  machinery. 
The  one  is  unable  to  learn  a  new  trade, 


or  to  excel  in  it  in  the  maturity  or  decline 
of  life,  and  has  no  reserved  capital,  on 
which  to  subsist  in  the  intermediate  pe- 
riod; and  the  other,  having  embarked 
his  capital  in  peculiar  connections,  finds 
it  difficult,  ana  even  impossible,  to  with- 
draw it  and  establish  any  new  and  pro- 
fitable business — so  that  the  first  are  gen- 
erally reduced  to  pauperism,  and  the  lat- 
ter to  bankruptcy.  It  is  with  each  an 
individual — a  personal  affair,  for  which 
there  is  no  compensation  in  the  general 
benefit  arising  to  the  community,  or  in 
the  aggrandizement  of  the  inventor. 
Nevertheless,  the  community  do  benefit 
immediately  and  remotely,  and  it  is,  there- 
fore, contended,  that  the  community  are 
thereby  qualified  to  indemnify  the  imme- 
diate sufferers,  and  that  laws  and  arrange- 
ments ought  to  be  made,  so  as  to  effect 
this  just  and  desirable  purpose.  This 
would  reconcile  the  conflicting  interests ; 
inventions  would  then  be  more  numerous 
and  better  encouraged,  and  a  fair  and 
reasonable  compensation  from  the  public 
stock  would  reconcile  all  parties  to  the 
progress  and  inventions  of  machinery. 

MADDER  (Rubia),  a  genus  of  plants 
including  an  extensive  family,  of  which 
the  galium  or  bedstraw  is  one  which 
closely  resembles  it  in  many  properties. 
Fifteen  species  of  it  are  known,  but  only 
one  is  indigenous  in  the  United.  States — 
the  R.  Brownii,  which  grows  in  Florida. 
Georgia,  and  Jamaica.  E.  Tinctoria  is 
the  most  important,  on  account  of  the 
fine  scarlet  color  imparted  by  its  roots, 
and,  it  is  so  essential  to  calico  printers, 
that  they  could  not  carry  on  their  busi- 
ness without  it.  Holland  grows  it  very 
largely,  and  importations  of  it  from  there 
occur  in  every  civilized  country.  France 
though  it  grows  some,  yet  imports  more 
from"  the  Levant.  From  its  great  con- 
sumption here,  it  has  become  an  object 
to  introduce  its  growth  and  cultivation 
into  this  country,  and  successful  efforts 
have  been  made  by  spirited  individuals. 
The  value  of  madder  imported  into  this 
country  is  considerable,  and  if  the  article 
is  welf  prepared,  there  seems  no  reason 
to  doubt  that  it  would  find  a  ready  mar- 
ket. Madder  was  successfully  introduced 
into  France  one  hundred  years  s^nce,  by 
Jean  Althen,  a  Persian,  to  whom  a  statue 
is  to  be  erected.  This  plant,  it  is  said, 
now  returns  to  France  nearly  25,000,000 
francs,  or  $5,000,000  per  annum.  The 
amount  of  the  madder  crop  varies  greatly 
one  year  with  another,  and  it  is  difficult 
to  give  the  mean  crop.  A  hectare  it  is 
said,  in  a  well  manured  ground  and  in 


mad] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


337 


favorable  circumstances  of  temperature, 
will  produce  5,000  killogrammes  of  dry 
roots,  while  in  unfavorable  circumstances 
it  will  not  yield  more  than  one-half  or 
one-fourth  of  this  amount.  A  kilogramme 
is  equal  to  2  lb.  2  oz.  From  the  com- 
mencement of  the  present  century,  the 
greatest  crops  are  stated  not  to  exceed 
^5,000  quintals  by  measure,  and  the  least 
about  10,000  to  12,000. 

The  average  amount  per  annum  of 
madder  imported  into  this  country,  as 
appears  by  returns  procured  at  the  Trea- 
sury Department,  from  1845  to  1847,  is 
about  6,110,000  pounds,  and  in  value, 
about  $600,000.  The  value  given  is  be- 
lieved, however,  to  be  too  low,  as  it  falls 
below  the  usual  wholesale  market  price, 
one-quarter  if  not  one-half. 

Mr.  Joseph  Swift,  of  Buckingham, 
Ohio,  is  probably  the  most  extensive  cul- 
tivator or  madder  in  the  Union.  His  first 
crop  was  harvested  in  the  fall  of  1842, 
after  being  allowed  four  seasons'  growth, 
and  produced  at  the  rate  of  2000  pounds 
per  acre. 

The  amount  of  labor  required,  includ- 
ing the  preparation  of  land,  planting,  cul- 
tivating, digging,  cleaning,  threshing, 
&c,  was  from  eighty  to  one  hundred 
days'  work  per  acre  (including  team 
work).  The  outlay  for  buildings,  fixtures, 
&c,  did  not  exceed,  in  all,  fifty  dollars. 

The  value  of  the  crop  was  at  the  rate 
of  fifteen  cents  per  pound,  at  which  price 
he  sold  most  of  it,  notwithstanding  the 
circumstance  of  its  being  unknown  to 
purchasers,  and  having  to  encounter  the 
prejudice  that  usually  exists  in  such  cases. 

The  result,  then,  in  figures,  fairly 
stated,  stands  thus,  for  an  acre  of  good 
land  properly  managed : 

By  2000  pounds  of  madder,  at  15  cents 

per  pound, $300  00 

Co7Ura— To  100  days1  work 

at  75  cents  per  day, $75  00 

Use  of  land  4  years  at  $4  per 

year, 16  00 

Grinding,  packing,  &c 9  00 

100  00 


Leaving  a  net  profit  per  acre  of. .  $200  00 

The  quality  of  this  madder  was  pro- 
nounced superior  to  most  of  the  import- 
ed ;  and  no  difficulty  was  found  in  selling 
it  wherever  it  became  known.  The  price 
of  madder  in  the  western  cities  (and  also 
at  the  east,)  has  varied  during  the  past 
five  years,  from  14  to  18  cents  per  pound  ; 
the  better  qualities  often  selling  at  18  to 
20  cents,- at  wholesale. 

The  yield  pet-  acre.  Mr.  S.  is  now  con- 
15 


vinced,  can  be  increased  to  3000  lbs. ;  and 
it  is  better  to  harvest  the  crop  at  the  end 
of  three  years'  growth,  than  to  allow  a 
longer  period.  This  plan  will  of  course 
nearly  double  the  profits. 

Madder  has  been  grown  successfully 
by  Mr.  Gilm,  a  resident  of  Long  Island. 
The  crop  does  not  require  much  atten- 
tion. For  the  first  year,  it  must  be  well 
wed  and  hoed  lightly  in  summer ;  in  the 
second  year,  hoeing  in  spring,  summer, 
and  fall ;  third  year,  the  same  repeated, 
and  earthing  up  the  roots  of  the  plants, — 
at  the  close  of  the  third  year  the  crop  may 
be  harvested:  after  this,  if  left  in  the 
ground,  it  loses  its  strength.  The  roots 
are  then  largest  and  fullest  of  coloring 
matter.  To  raise  them,  a  trench  is  dug 
round  the  roots,  the  earth  loosened,  and 
the  whole  roots  of  one  plant  raised  to- 
gether ;  these  often  weigh  40  lbs. :  this 
diminishes  by  drying,  to  three-fom-ths  of 
its  weight.  Sometimes  madder  is  grown 
by  setting  out  the  roots.  Twenty  "thou- 
sand plants  are  allotted  to  an  acre.  Roots 
the  size  of  a  quill  are  esteemed  most,  or 
not  bigger  than  the  little  finger.  After 
being  picked  it  must  be  dried  previous  to 
grinding  and  preservation.  In  hot  cli- 
mates air-drying  is  used ;  stoves  are  used 
in  Holland.  The  madder  from  Holland 
is  most  esteemed,  and  it  is  cultivated  in 
that  country  to  a  great  extent.  In  pow- 
der, it  is  of  an  orange-brown  color,  but  is 
liable  to  become  damp,  and  to  be  spoiled, 
if  kept  in  a  moist  place. 

Madder  is  used  for  dyeing  woollen, 
silk,  and  also  cotton  goods,  and  the  color 
is  very  lasting,  and  resists  the  action  of 
the  air  and  sun.  Within  a  few  years,  a 
method  has  been  discovered  of  rendering 
the  red  exceedingly  brilliant  and  ap- 
proaching to  purple.  It  also  forms  a  tint 
for  several  other  shades  of  color :  it  has 
the  curious  properties  of  tinging  the 
bones  red  of  those  animals  which  feed 
upon  the  roots. 

It  appears  that  madder  may  be  consid- 
ered as  composed  of  two  coloring  sub- 
stances, one  of  which  is  dun  (tawny), 
and  the  other  is  red.  Both  of  these  sub- 
stances may  combine  with  the  stuff.  It 
is  of  consequence,  however,  to  fix  only 
the  red  part.  The  dun  portion  appears 
to  be  more  soluble,  but  its  fixity  on  stuffs 
may  possibly  be  increased  by  the  affinity 
which  it  has  for  the  red  portion. 

The  different  additions  made  to  mad- 
der, and  the  multiplied  processes  to 
which  it  is  sometimes  exposed,  havepro- 
bably  this  separation  for  their  chiei  ob- 
ject. 


338 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[MAi 


The  red  portion  of  madder  is  soluble,  1 
but  in  small  quantity,  in  water.    Hence  \ 
but  a  limited  concentration  can  be  given  j 
to  its  solution.      If  the  portion  of  this 
substance  be  too  much  increased,  so  far  j 
from  obtaining  a  greater  effect,  we  merely 
augment  the  proportion  of  the  dun  part, 
which  is  the  more  soluble  of  the  two. 

In  consequence  of  the  Societe  Indus- 
trielle  of  Mulhausen  having  offered  in  the 
year  1826  large  premiums  to  the  authors 
of  the  best  analytical  investigation  of 
madder,  eight  memoirs  were  transmitted 
to  it  in  the  year  1827.  They  were  ex- 
amined with  the  greatest  care  by  a  com-  I 
mittee  consisting  of  able   scientific  and  ; 

Eractical  men.  None  of  the  competitors  ! 
owever  fulfilled  the  conditions  of  the 
programme  issued  by  the  society ;  but 
four  of  them  received  a  tribute  of  esteem 
and  gratitude  fi-oin  it;  MM.  Kobiquet 
and  Colin  at  Paris,  Kuhlmann  at  Lille, 
and  Houton-Libillardiere.  Fresh  pre- 
miums were  offered  for  next  year,  to  the 
amount  of  2000  francs. 

Every  real  discovery  made  concerning 
this  precious  root,  would  be  of  vast  con- 
sequence to  dyers  and  calico-printers. 
Both  M.  Kuhlmann,  and  Kobiquet  and 
Colin,  conceived  that  they  had  discovered 
a  new  principle  in  madder,  to  which  they 
gave  the  name  alizarine.  The  latter  two 
chemists  treated  the  powdered  madder 
with  sulphuric  acid,  taking  care  to  let  it 
heat  as  little  as  possible.  By  this  action 
the  whole  is  carbonized,  except  perhaps 
the  red  matter.  The  charcoal  this  ob- 
tained is  pulverized,  mixed  with  water, 
thrown  upon  a  filter,  and  well  washed  in 
the  cold.  It  is  next  dried,  ground,  and 
diffused  through  fifty  parts  of  water,  con- 
taining six  parts  of  alum.  This  mixture 
is  then  boiled  for  one  quarter  of  an  hour, 
and  thrown  upon  a  filter  cloth  while  boil- 
ing hot.  The  residuum  is  once  more 
treated  with  a  little  warm  alum  water. 
The  two  liquors  are  to  be  mixed,  and  one 
part  of  sulphuric  acid  poured  into  them  ; 
when  they  are  allowed  to  cool  with  occa- 
sional agitation.  Flocks  now  make  their 
appearance  ;  the  clear  liquid  is  decanted, 
and  the  grounds  are  thrown  upon  a  filter. 
The  precipitate  is  to  be  washed,  first  with 
acidulated  water,  then  with  pure  water, 
and  dried,  when  the  coloring  matter  is 
obtained  in  a  red  or  purple  state.  This 
purple  substance,  when  heated  dry,  gives 
out  alizarine,  and  an  empyreumatic  oil, 
having  an  odor  of  animal  matter ;  while 
a  chareoally  matter  remains. 

M.  Dan.  Kcechlin,  the  justly  celebrated 
calico  printer  of  Mulhausen,  has  no  faith 


in  alizarine  as  the  dyeing  principle  of 
madder ;  and  thinks  moreover  that,  were 
it  of  value,  it  could  not  be  extracted  on 
the  great  scale,  on  account  of  the  destruc- 
tive heat  which  would  result  from  the 
acid  acting  upon  a  considerable  body  of 
the  ground  madder.  Their  alizarine  is 
not  a  uniform  substance,  as  it  ought  to 
be,  if  a  proximate  principle  ;  for  samples 
of  it  obtained  in  different  repetitions  of 
the  process  have  produced  very  variable 
effects  in  dyeing.  The  madders  of  Avig- 
non, though  richer  in  color  than  those  of 
Alsace,  afford  however  little  or  no  aliza- 
rine. In  fact,  purpurine,  the  crude  sub- 
stance from  which  they  profess  to  extract 
alizarine,  is  a  richer  dye  than  this  pare 
substance  itself. 

Madder  contains  so  beautiful  and  so 
fast  a  color,  that  it  has  become  of  almost 
universal  employment  in  dyeing;  but 
that  color  is  accompanied  with  so  many 
other  substances  which  mask  and  de- 
grade it,  that  it  can  be  brought  out  and 
fixed  only  after  a  series  of  operations 
more  or*  less  difficult  and  precarious. 
This  dye  is  besides  so  little  soluble,  that 
much  "of  it  is  thrown  away  in  the  dye- 
house  ;  the  portion  supposed  to  be  ex- 
hausted being  often  as  rich  as  other  fresh 
madder;  hence  it  would  be  a  most  valu- 
able improvement  in  this  elegant  art  to 
insulate  this  tinctorial  body,  and  make  it 
a  new  product  of  manufacture. 

According  to  Wolff  and  A.  Streeker  the 
composition  of  these  two  substances  is, 

Alizarine C  2°  H  «  O  • 

Purpurine C  1S  H  6  0  6 

Purpurine  furnishes,  like  alizarine,  all 
the  colors  produced  by  madder.  It  may 
be  separated  from  alizarine  by  a  boiling 
solution  of  alum,  in  which  it  dissolves : 
with  potash  it  gives  a  currant  red  solu- 
tion, while  alizarine  gives  a  blue  by  re- 
flected, and  a  purple  by  transmitted  light. 
Both  are  converted  by  nitric  acids  into 
phtalic  and  oxalic  acids.  When  madder 
is  fermented  by  yeast  only  purpurine  can 
be  detected.  "The  alizarine  being  con- 
verted into  that  substance  with  the  evo- 
lution of  carbonic  acid  and  hydrogen. 
Schunck  has  demonstrated  the  presence 
of  a  bitter  substance  called  by  him  rubian : 
it  is  not  a  coloring  matter  itself,  but  is  in 
some  wav  connected  with  the  production 
of  the  coloring  principles.  It  is  a  hard, 
drv,  brittle,  shining  substance,  like  gum 
soluble  in  water  and  alchohol.  When 
acted  on  by  sulphuric  and  hydrodoric 
acids  \  he  products  of  the  decomposition 
are: — 1,  alizarine;   2,  verantine;   3,  ru- 


mad] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


339 


biretine ;  4,  rubianine.  Scliunck  believes 
that  alizarine  and  verantine  form  with 
alumina  a  compound  soluble  in  boiling 
water,  which  is  identical  with  purpurine. 

It  is  a  curious  fact  that  madder  grown 
on  ground  deficient  in  lime  will  not  give 
much  coloring  matter,  but  when  the 
ground  has  been  well  limed  an  abundance 
of  red  coloring  matter  is  produced. 

By  digesting  powdered  madder  in 
water,  and  acting  upon  the  jelly  like 
solution  thus  obtained,  by  boiling  al- 
cohol, an  extract  is  afforded,  which,  at  a 
subliming  heat,  yields  the  proper  red 
coloring     matter,      or      alizarine.       Or 

f ground  madder  may  be  treated  direct- 
y  with  boiling  alcohol  j  and  to  the  solu- 
tion dilute  sulphuric  acid  is  added,  which 
precipitates  the  alizarine  in  a  copious 
orange  precipitate.  Another  principle, 
xanthine,  is  obtained  from  a  fawn-yellow 
matter,  soluble  in  alcohol  and  water,  by 
precipitation  with  oxide  of  lead,  washing 
the  precipitate  with  alcohol,  and  extract- 
ing the  color  with  sulphuric  acid.  It 
has  an  orange  green  tint,  and  a  saccha- 
rine taste.  It  is  believed  that  xanthine 
prevails  in  the  rose  colored  tints  of  mad- 
der, and  is  absent  in  the  violet. 

The  red  mordants  are  prepared  com- 
monly in  Alsace,  as  follows : — The  crush- 
ed alum  and  acetate  of  lead  being 
weighed,  the  former  is  put  into  a  deep 
tub,  and  dissolved  by  adding  a  proper 
quantity  of  hot  water,  when  about  one 
tenth  of  its  weight  of  soda  crystals  is  in- 
troduced to  saturate  the  excess  of  acid  in 
the  alum.  The  acetate  of  lead  is  now 
mixed  in  ;  and  as  this  salt  dissolves  very 
quickly,  the  reaction  takes  place  almost 
instantly.  Care  must  be  taken  to  stir  it  for 
an  hour.  The  vessel  should  not  be  covered, 
lest  its  contents  should  cool  too  slowly. 

Much  mordant  should  not  be  prepared 
at  once,  for  sooner  or  later  it  will  deposit 
some  sub-acetate  of  alumina.  This  de- 
composition takes  place  even  in  corked 
vials  in  the  cold  ;  and  the  precipitate  does 
not  readily  dissolve  again  in  acetic  acid. 
All  practical  men  know  that  certain  alu- 
minous mordants  are  decomposed  by 
heating  them,  and  restored  on  cooling. 
Gay  Lussac  observed,  that  by  adding  to 
pure  acetate  of  alumina,  some  alum  or 
sulphate  of  potash,  the  mixture  acquires 
the  property  of  forming  a  precipitate  with 
a  heat  approaching  the  boiling  point,  and 
of  re-dissolving  on  cooling.  The  pre- 
cipitate is  alumina  nearly  pure,  accord- 
ing to  M.  Gay  Lussac  ;  but,  by  M.  Kcech- 
lin's  more  recent  researches,  it  is  shown 
to  be  sub-sulphate  of  alumina,  containing 


eight  times  as  much  base  as  the  neutral 
sulphate. 

Madder  dye. — On  account  of  the  feeble 
solubility  of  its  coloring  matter  in  water, 
we  cannot  dye  with  its  decoction  ;  but 
we  must  boil  the  dye-stuff  along  with  the 
goods  to  be  dyed ;  whereby  the  water 
dissolves  fresh  portions  of  the  dye,  and 
imparts  it  in  succession  to  the  textile 
fibres.  In  dyeing  with  madder,  we  must 
endeavor  to  fix  as  little  of  the  dun  matter 
as  possible  upon  the  cloth. 

Dyeing  on  wool. — Alumed  wool  takes, 
in  the  madder  bath,  a  red  color,  which 
is  not  so  bright  as  cochineal  red,  but  it  is 
faster  ;  and  as  it  is  far  cheaper,  it  is  much 
used  in  England  to  dye  soldiers'  cloth. 
A  mordant  of  alum  and  tartar  is  employ- 
ed ;  the  bath  of  madder,  at  the  rate  of 
from  8  to  18  ounces  for  the  pound  of 
cloth,  is  heated  to  such  a  degree  that  we 
can  just  hold  our  hand  in  it,  and  the 
goods  are  then  dyed  by  the  wince,  with- 
out heating  the  bath  more  till  the  color- 
ing matter  be  fixed.  Vitalis  prescribes  as 
a  mordant,  one  fourth  of  alum,  and  one 
sixteenth  of  tartar;  and  for  dyeing,  one 
third  of  madder,  with  the  addition  of  a 
24th  of  solution  of  tin  diluted  with  its 
weight  of  water.  He  raises  the  tempera- 
ture in  the  space  of  an  hour  to  200°,  and 
afterwards  he  boils  for  3  or  4  minutes  ;  a 
circumstance  which  is  believed  to  con- 
tribute to  the  fixation  of  the  color.  The 
bath,  after  dyeing,  appears  much  loaded 
with  yellow  matter,  because  this  has  less 
affinity  for  the  alum  mordant  than  the 
red.  Sometimes  a  little  archil  is  added  to 
the  madder,  to  give  the  dye  a  pink  tinge ; 
but  this  is  fugitive. 

Silk  is  seldom  dyed  with  madder,  be- 
cause cochineal  affords  brighter  tints. 

Dyeing  on  cotton  and  linen. — The  most 
brilliant  and  fastest  madder  red  is  the 
Turkey  or  Adrianople.  The  common 
madder  reds  are  given  in  the  following 
way : — The  yarn  or  cloth  is  boiled  in  a 
weak  alkaline  bath,  washed  dried  and 
galled,  by  steeping  the  cotton  in  a  decoc- 
tion of  bruised  galls  or  of  sumach.  After 
drying,  it  is  twice  alumed;  for  which 
purpose,  for  every  four  parts  of  the  goods, 
one  part  of  the  alum  is  taken,  mixed  with 
l-16th  of  its  weight  of  chalk.  The  goods 
are  dipped  into  a  warm  solution  of  the 
alum,  wrung  out,  dried,  and  alumed 
afresh,  with  half  the  quantity.  The  ace- 
tate of  alumina  mordant,  described 
above,  answers  much  better  than  com- 
mon alum  for  cotton.  After  the  goods 
are  dried  and  rinsed,  they  are  passed 
through  the  dye-bath,  which  is  formed 


340 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


of  |  lb.  of  good  madder  for  every  pound 
of  cotton  ;  and  it  is  raised  to  the  boiling  \ 
point  by  degrees,  in  the  space  of  50  or  60  i 
minutes.  Whenever  the  ebullition  has  ; 
continued  a  few  minutes,  the  goods  must  ■ 
be  removed,  washed  slightly,  and  dyed  a  j 
second  time  in  the  same  way,  with  as  j 
much  madder.  They  are  then  washed  ! 
and  passed  through  a  warm  soap  bath,  I 
which  removes  the  dun  coloring  matter,    j 

Holterhoff  prescribes  for  ordinary  j 
madder  red  the  following  proportions : —  j 
20  pounds  of  cotton  yarn  ;  14  pounds  of 
Dutch  madder ;  3  pounds  of  nut-galls ; 
6  pounds  of  alum ;  to  which  i  pound  of 
acetate  of  lead  has  been  first  added,  and 
then  a  quarter  of  a  pound  of  chalk. 

In  the  calico  print-works  the  madder 
goods  are  passed  through  a  bran  bath 
first,  immediately  after  dyeing;  next, 
after  several  days  exposure  to  the  air, 
when  the  dun  dye  has  become  oxidized, 
and  is  more  easily  removed.  An  addi- 
tion of  chalk,  on  the  principles  explained 
above,  is  sometimes  useful  in  the  madder 
bath.  If  bran  be  added  to  the  madder 
bath,  the  color  becomes  much  lighter, 
and  of  an  agreeable  shade.  Sometimes 
bran-water  is  added  to  the  madder  bath, 
instead  of  bran. 

The  ordinary  madder-red  dye  is  given 
in  the  following  way : — The  yarn,  or 
cloth,  is  put  into  a  very  weak  alkaline 
bath,  at  the  boiling  temperature,  then 
washed,  dried,  and  galled;  or,  when  the 
calico  is  to  be  printed,  for  this  bath  may 
be  substituted  one  of  cow-dung,  subse- 
quent exposure  to  the  air  for  a  day  or 
two,  and  immersion  in  very  dilute  sul- 
phuric acid.  In  this  way  the  stuff  be- 
comes opened,  and  takes  and  retains  the 
color  better.  After  the  galling,  the  goods 
are  dried,  and  alumed  twice  ;  then  dried, 
rinsed,  and  passed  through  the  madder- 
bath.  This  is  composed  of  three-fourths 
of  a  pound  of  good  madder  for  every 
pound  weight  of  the  goods.  The  bath  is 
Blowly  raised  to  the  boiling  point  in  the 
course  of  50  or  60  minutes,  more  or  less, 
according  to  the  shade  of  color  wished 
for.  When  the  boiling  has  continued 
for  a  few  minutes,  the  stuff  is  taken  out, 
Washed  slightly,  and  dried  a  second  time 
in  the  same  manner,  and  with  as  much 
madder.  It  is  then  washed  and  dried,  or 
passed  through  a  hot  soap-bath,  which 
carries  off  the  fcvwa-colored  particles. 
Other  dyes,  likewise,  are  added  to  the 
madder-bath,  to  obtain  other  shades  of 
color*  for  instance,  a  decoction  of  fustic, 
wcld,log-wood,  quercitron,  knoppern,  the 
mordants  being  modified  accordingly. 


Holterhoff  prescribes,  for  ordinary 
madder-red,  the  following  proportions : 
20  lbs.  of  cotton-yarn,  14  lbs.  of  Dutch 
madder,  3  lbs.  of  gall-nuts,  5  lbs.  of 
alum ;  to  which  are  added,  first  14  lb.  of 
acetate  of  lead,  and,  subsequently,  \  lb. 
of  chalk.  When  bran  is  added  to  the 
madder-bath,  the  color  becomes  much 
lighter,  and  of  a  more  agreeable  tint. — 
Adrianople  inadder-red  is  given  by  many 
distinct  operations.  The  first  consists  in 
cleansing  or  scouring  the  goods  by  alka- 
line baths,  after  which  they  are  steeped 
in  oily  liquors,  brought  to  a  creamy  state 
by  a '  little  carbonate  of  soda  solution. 
Infusion  of  sheeps'-dung  is  often  used  as 
an  intermediate,  or  secondary  steep. 
The  operation  of  oiling,  with  much  man- 
ual labor,  and  then  removing  the  super- 
fluous or  loosely-adhering  oil,  with  an 
alkaline  bath,  is  repeated  two  or  three 
times,  taking  care  to  dry  hard  after  eaeh 
process.  Then  follows  the  galling,  alum- 
mg,  maddering,  and  brightening,  for  re- 
moving the  dun-colored  principle,  by 
boiling  at  an  elevated  temperature,  with 
alkaline  liquids  and  soap.  The  whole  is 
often  concluded  with  a  rosing  by  salt  of  tin. 

According  to  the  latest  improvement 
of  the  French  dyers,  each  of  the  four  pro- 
cesses of  oiling,  mordanting,  dyeing,  and 
brightening  differs,  in  some  respects, 
from  the  above. 

1.  Their  first  step  is  boiling  the  cloth 
for  four  hours,  in  water  containing  one 

?ound  of  soap  for  every  four  pieces, 
heir  saponaceous  bath  of  a  creamy 
aspect  is  used  at  a  temperature  of  75°  F. ; 
and  it  is  applied  by  the  padding  machine 
6  times,  with  the  grassing  and  drying 
alterations.  In  winter,  when  the  goods 
cannot  be  exposed  on  the  grass,  no  less 
than  12  alternations  of  the  saponaceous  or 
white  bath  are  employed,  and  8  in  spring. 
They  consider  the  action  of  the  sun- 
beams to  aid  greatly  in  brightening  this 
dye ;  but  at  midsummer,  if  it  be  con- 
tinued more  than  4  hoars,  the  scarlet 
color  produced  begins  to  be  impaired. 

They  conceive  that  the  oilinsr  opera- 
tion impregnates  the  fibres  with  super- 
margarate  of  potash  or  soda,  insoluble 
salts  which  attack  and  condense  the  alu 
mina,  and  the  red  coloring  particles  of 
the  madder,  so  firmly  that  they  can  resist 
the  clearing  boil. 

2.  Their  second  step,  the  mordanting, 
consists  first  in  padding  the  pieces 
through  a  decoction  of  galls  mixed  with 
a  solution  of  equal  weight  of  alum  ;  and 
after  drying  in  the  hot  flue,  &c,  again 
padding  them  in  a  solution  of  an  acetate 


mag] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


341 


of  alumina,  made  by  decomposing  a  sol- 
ution of  16  lbs.  of  alum  with  16  lbs.  of 
acetate  of  lead,  for  6  pieces  of  cloth,  each 
32  amies  long. 

8.  The  maddering  is  given  at  two  suc- 
cessive operations ;  with  4  pounds  of 
Avignon  madder  per  piece  at  each  time. 

4.  The  brightening  is  performed  by  a 
12  hours'  boil  in  water  with  soda  crystals, 
soap,  and  salt  of  tin ;  and  the  rosing  by 
a  10  hours1  boil  with  soap  and  salt  of  tin. 
Occasionally,  the  goods  are  passed 
through  a  weak  solution  of  chloride  of 
potash.  When  the  red  has  too  much  of 
a  crimson  cast,  the  pieces  are  exposed  for 
two  days  on  the  grass,  which  gives  them 
a  bright  scarlet  tint. 

MAGNESIA.  A  white,  tasteless, 
earthy  substance,  usually  obtained  by  ex- 
posing its  hydratcd  carbonate  to  a  red 
heat.  Its  specific  gravity  is  2-3.  It  is 
almost  insoluble ;  but  when  moistened 
and  put  upon  turmeric  paper  it  reddens 
it :  this  sometimes  depends  upon  a  trace 
of  lime.  It  is  an  oxide  of  a  brilliant  white 
metal,  which  has  been  called  magnesium, 
and  which  may  be  obtained  by  heating 
chloride  of  magnesium  with  potassium  : 
they  act  intensely  upon  each  other,  chlo- 
ride of  potassium  is  formed,  and  magne- 
sium separates  :  it  may  be  washed  with 
water  and  dried.  Heated  to  redness  in 
the  air,  it  burns  with  great  brilliancy  into 
magnesia,  12  parts  of  the  metal  combin- 
ing with  8  of  oxygen  to  form  20  of  mag- 
nesia. In  commerce,  pure  magnesia  is 
generally  distinguished  by  the  term  cal- 
cined magnesia  :  and  the  hydrated  carbo- 
nate of  magnesia,  obtained  by  precipitat- 
ing a  solution  of  sulphate  of  magnesia  by 
carbonate  of  soda,  and  washing  and  dry- 
ing the  precipitate,  goes  by  the  name  of 
magnesia,  or  magnesia  alba.  The  chief 
use  of  magnesia  and  its  carbonate  is  in 
medicine.  Sulphate  of  magnesia  is  ob- 
tained by  evaporating  the  residue  of  sea- 
water  after  the  common  salt  has  been  se- 
parated, or  by  adding  sulphuric  acid  to 
bittern  and  evaporating,  so  as  to  obtain 
the  resulting  sulphate  of  magnesia.  This 
salt  is  also  obtained  by  the  action  of  di- 
lute sulphuric  acid  on  magnesian  lime- 
stone, and  it  is  not  uncommon  in  mine- 
ral waters4:  it  was  formerly  procured  from 
certain  springs  near  Epsom,  in  Surrey, 
and  was  hence  termed  Epsom  salt.  It 
crystallizes  in  four-sided  prisms  with  di- 
hedral summits.  Its  crystals  are  soluble 
in  their  weight  of  water  at  60°,  and  in 
three-fourths  their  weight  at  212°.  They 
melt  when  heated,  and  gradually  lose 
their  water  of  crystallization.    They  con- 


sist of  20  magnesia,  40  sulphuric  acid,  and 
63  water.  Ihis  salt  is  a  useful  purgative 
in  medicine,  and  is  the  chief  source  of  the 
other  forms  of  magnesia.  All  the  mag- 
nesian salts  have  a  peculiar  bitterish  fla- 
vor. Magnesia  is  found  native  in  the 
state  of  hydrate  and  carbonate ;  it  exists 
as  a  compound  part  of  several  minerals, 
and  many  of  them  are  soft  or  soapy  to 
the  touch. 

The  carbonate  of  magnesia  may  be  made 
thus : — 

Dissolve  four  parts  of  sulphate  of  mag- 
nesia, and  three  parts  of  subcarbonate  of 
potash,  separately,  in  twice  their  weight 
of  water,  and  filter  them.  Then  mix 
them  with  eight  times  their  weight  of 
boiling  water.  Boil  and  stir,  and  then 
stand  till  partly  cool;  when,  being  strain- 
ed through  linen,  the  carbonate  remains. 
Wash  it  and  dry  it  gradually.  It  is  the 
best  anti-acid  in  the  stomach,  and  the 
acid  renders  it  purgative. 

It  is  however  liable  to  produce  accumu- 
lations in  the  bowels.  Almost  all  the 
Epsom  salts  used  in  the  United  States  is 
manufactured  at  Baltimore  from  the  mag- 
nesite  and  magnesian  limestone  found  in 
Lancaster  county,  Pa.  The  annual  a- 
mount  manufactured  there  is  about  1,500,- 
000  lbs. 

Hydrate  of  Magnesia  or  native  Magnesia 
is  found  at  Hoboken,  N.  J.,  in  thin 
seams  traversing  serpentine.  The  Sili- 
ceous hydrate  is  found  in  serpentine  at, 
Middlefield,  Mass.,  and  at  Baltimore,  Md. 
A  variety  of  carbonate  containing  4  per 
cent,  of  silex  is  called  by  the  Germans 
Meerschaum,  or  Ecume  de  mer  by  the 
Erench.  This  is  also  found  at  Hoboken. 
Sulphate  of  magnesia  in  fine  silky  needles 
is  found  in  caves  in  Kentucky,  and  efflo- 
rescing in  the  earth  in  Tennessee. 

MAGNESIAN  LIMESTONE.  An  ex- 
tensive series  of  beds  lying  in  geological 
position  immediately  above  the  coal  mea- 
sures ;  so  called  because  the  limestone, 
which  is  the  principal  member  of  the 
series,  contains  magnesia. 

It  is  composed  of  carbonate  of  magne- 
sia 46-5,  carbonate  of  lime  52,  with  1  of 
iron  and  manganese.  Or,  magnesia  20-3, 
lime  29*5,  combined  with  47*2  of  carbonic 
acid,  and  1  of  iron  and  alumine.  Ano- 
ther variety  is  36  carbonate  of  magnesia 
and  62  carbonate  of  lime.  The  introduc- 
tion of  magnesia  into  limestones  has  not 
yet  been  dearly  explained. 

Magnesian  limestone  is  used  chiefly  for 
manufacturing  the  salts  of  magnesia  from. 
It  ought  never  be  burned  into  lime  to  be 
used  as  dressing  on  land ;  for  the  magne- 


342 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[man 


eia  remains  so  long  caustic  in  the  ground 
that  the  roots  of  plants  are  injured  and 
killed  by  it. 

MAGNESITE.    Native  masrnesia. 

MAGNESIUM.  The  metallic  base  of 
magnesia ;  which  see. 

MAGNETIC  COMPENSATOR.  A 
contrivance  devised  by  Mr.  Barlow  for 
eliminating  the  influence  of  a  ship's  guns 
and  other  iron  in  deranging  the  bearings 
of  the  compass.  It  consists  of  a  plate  or 
combination  of  plates  of  iron  placed  near 
the  binnacle,  so  as  to  counteract,  by  an 
equal  and  opposite  attraction,  that  of  the 
rest  of  the  iron  on  board  the  vessel.  Mr. 
Airy  has  investigated  the  law  of  disturb- 
ance in  the  case  of  vessels  built  of  iron, 
and  shown  that  the  disturbing  force  con- 
sists of  a  very  large  force  of  permanent 
magnetism  in  the  rolled  and  hardened 
plates  employed  in  the  construction  of 
the  vessel,  and  a  very  small  force  of  in- 
duced magnetism,  which  changes  with 
the  place  of  the  ship,  or  rather  with  the 
varying  circumstances  of  terrestrial  mag- 
netism by  which  it  is  produced.  Mr. 
Airy  has  given  a  set  of  practical  rules  for 
correcting  the  disturbing  forces  by  means 
of  two  powerful  magnets  placed  at  right 
angles  to  each  other  below  the  compass, 
and  a  box  of  small  iron  chain,  which 
is  used  instead  of  Barlow's  correcting 
plate. 

MAGNET,  NATURAL.  One  of  the 
numerous  oxides  of  iron ;  possessed, 
however,  of  properties  peculiar  to  itself, 
if  we  except  the  metals  nickel  and  co- 
balt, which  possess  it  also  in  a  very  slight 
degree.  The  masrnet  consists  chiefly  of 
two  oxides,  together  with  a  small  portion 
of  quartz  and  alnmine.  Its  color  varies 
in  different  specimens,  according  to  mi- 
nute differences  in  the  ratios  of  the  two 
oxides,  and  the  nature  of  the  foreign 
substances  with  which  they  are  found 
united ;  but  it  is  usually  of  a  dark-array 
hue,  and  has  a  dull  metallic  lustre.  It  is 
found  in  considerable  masses  in  the  iron 
mines  of  Sweden  and  Norway;  in  the 
Isle  of  Elba;  in  different  parts  of  Arabia, 
China,  Siam,  and  the  Philippine  Islands. 
Small  magnets  are  also  occasionally, 
though  rarely,  met  with  among  the  iron 
ores  of  this  country.  The  properties  are  : 

1.  It  attracts  iron  in  all  its  states  ex- 
cept the  oxides. 

2.  If  formed  into  a  bar,  and  suspended 
freely  by  a  hair,  or  on  a  pivot  passing 
through  its  centre,  it  will  turn  itself 
round,  and,  after  a  few  pendulous  vibra- 
tions, settle  into  some  one  position ; 
Which  it  will  retain  if  left  undisturbed, 


or  if  disturbed  will,  after  a  few  similar 
vibrations,  return  to  it  again  as  before. 

3.  By  rubbing  on  a  bar  of  steel  it  will 

five  the  bar  the  same  properties  ;  and  a 
ar  of  soft  iron  will,  while  contiguous  to 
it,  even  when  not  touched  by  it,  obtain 
the  same  properties,  which,  however, 
the  iron  does  not,  like  the  steel,  retain 
upon  removal. 

4.  The  position  of  rest  is  different  at 
different  places,  and  different  at  the  same 
place  at  distant  periods  of  time. 

A  great  number  of  amusing  toys  have 
been  formed  of  this  substance,  and  the 
phenomena  are  often  at  first  sight  very 
surprising ;  but  its  application  to  the 
purposes  of  navigation  renders  it  one  of 
the  most  important  discoveries  ever  made. 
The  earlier  navigators  believed  that  it 
pointed  always  to  the  north  pole  of  the 
world ;  and  that,  therefore,  by  means  of 
it  they  could  always  at  once  tell  the  di- 
rection of  their  meridian,  and  conse- 
quently in  what  direction  they  were  sail- 
ing. It  was  hence  called  the  loadstone, 
or  leading  stone. 

The  employment  of  the  loadstone  itself 
for  the  purposes  of  navigation  has  long 
been  laid  aside  :  as  artificial  magnets  can 
be  constructed  having  a  much  greater  in- 
tensity of  directive  power. 

MAGNETIC  NEEDLE.  An  instru- 
ment suspended  by  its  centre,  and  mag- 
netized, which  shows  the  direction  of  the 
resultant  of  the  magnetic  forces  at  the 
place  of  observation. 

MAGNETIC  PYRITES.  Native  black 
sulphuret  of  iron  ;  it  attracts  the  mag- 
netic needle. 

MALTHA.  Mineral  pitch.  It  is  no- 
thing more  than  thickened  petroleum  or 
rock  oil. 

MANGANESE.  This  name  is  gene- 
rally given  to  a  black  mineral,  originally 
described  in  the  year  1774,  by  Scheele, 
as  a  peculiar  earth,  and  which  was  after- 
wards shown  by  Gahn  to  be  the  oxide 
of  a  metallic  substance  which  he  called 
magnesium.  This  term,  however,  having 
been  applied  to  the  metallic  base  of  mag- 
nesia, the  word  manganese  has  been 
adopted  to  designate  the  metal,  and  the 
ore  above  alluded  to  has  been  called 
black,  or  peroxide  of,  manganese.  The 
metal  itself  has  a  specific  gravity  of  about 
8.  It  is  gray,  hard,  brittle,  and  very  dif- 
ficult of  fusion,  and  has  not  been  applied 
to  any  use.  The  black  oxide,  on  the 
contrary,  is  largelj'  employed  as  a  source 
of  oxysren,  and  is  especially  important 
from  the  use  which  is  made  of  it  in  the 
decomposition  of  common  salt  for  the 


man] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


343 


production  of  chlorine.  Manganese  may 
be  represented  by  the  equivalent  28; 
and  the  black  oxide,  being  a  compound 
of  1  atom  of  manganese  and  2  of  oxygen, 
has  the  equivalent  44  (28  +  16).  There 
is  also  a  protoxide  of  manganese,  com- 
posed of  2S  metal  +  8  oxygen,  which  is 
the  basis  of  the  salts  of  this  metal. 
When  hydrate  or  carbonate  of  potassa, 
or  nitre,  are  fused  with  peroxide  of  man- 
ganese in  an  open  vessel,  a  dark-colored 
compound  is  obtained,  long  known  under 
the  name  of  chameleon  mineral,  in  conse- 
quence of  its  yielding  in  cold  water  a  so- 
lution which  is  at  first  green,  then  blue, 
purple,  red,  brown,  and  ultimately  depo- 
sits a  brown  powder,  and  becomes  color- 
less. This  substance  has  since  been 
termed  manganate  of  potash,  and  has 
been  provtd  to  contain  a  compound  of  1 
atom  of  manganese  and  3  of  oxygen, 
which  has  been  called  manganic  acid, 
and  is  represented  by  the  equivalent  52. 
In  the  pink  solution,  which  is  produced 
at  once  t>y  the  action  of  hot  water,  man- 
ganese exists  in  a  still  higher  state  of  ox- 
ldizement,  forming  the  per-manganic 
acid,  in  which  2  atoms  of  manganese  are 
combined  with  7  of  oxygen.  Both  these 
compounds  are  very  easy  of  decompo- 
sition. Some  of  the  proto-salts  of  man- 
ganese have  lately  been  used  in  calico- 
printing  as  the  source  of  brown  colors, 
and  occasionally  as  deoxidizing  agents. 

The  black  oxide  of  manganese  occurs 
abundantly  in  Vermont  at  Bennington 
and  Monckton,  accompanied  with  haema- 
tite. Black  wad  is  only  found  in  Con- 
necticut. Phosphate  of  manganese  is 
met  with  at  Washington,  Ct.  Sulphuret 
of  manganese  is  found  in  New-York. 

Manganese  is  found  native  eombined 
with  iron,  and  when  added  artificially  to 
steel  it  improves  the  quality.  Gold  and 
iron  are  rendered  more  fusible  by  its  ad- 
dition, and  the  iron  becomes  more  duc- 
tile. Copper  becomes  whiter,  less  fusi- 
ble, and  more  liable  to  tarnish.  The 
most  extensive  use  of  oxide  of  manga- 
nese is  in  bleaching  to  produce  chlorine, 
and  it  is  often  desirable  to  test  the  value 
of  these  ores. 

M.  Gay  Lussac  has  proposed  to  deter- 
mine the  commercial  value  of  manganese 
ore  by  the  quantity  of  chlorine  which  it 
affords  when  treated  with  liquid  muri- 
atic acid.  He  places  the  manganese 
powder  in  a  small  retort  or  mattress, 
pours  over  it  the  acid,  and  the  chlorine 
being  disengaged  with  the  aid  of  a  gen- 
tle heat,  is  transmitted  into  a  vessel  con- 
taining milk  of  lime  or  potash  water. 


This  liquor  is  thereafter  poured  into  a 

1  dilute   solution  of  suiphate  of  indigo: 

and  the  quantity  of  chlorine  is  inferred 

j  from  the  quantity  of  the  blue  solution 

:  which  is  decolored. 

This  mode  of  testing  is  easily  under- 
stood.    When  muriatic  acid  is  acted  on 

!  by  manganese  ore,  the  black  oxide  in  it 

|  yields  up  one  equivalent  of  its  oxygen, 
and  becomes  reduced  to  the  condition  of 
protoxide  of  manganese  :  the  atom  of 
oxygen  seizes  on  the  equivalent  of  hy- 

I  drogen  in  the  muriatic  acid,  and  sets  the 
chlorine,   the  other  element  of  the  acid, 

j  free ;  and  thus  for  every  one  atom  of 
manganese  present  one  atom  of  chlorine 
is  liberated.  If  the  amount  of  the  latter 
is  determined,  it  of  course  represents 
the  weight  of  manganese. 

The  manufacturer  of  flint  glass  uses  a 
small  proportion  of  the  black  manganese 
ore,  to  correct  the  green  tinge  which  his 
glass  is  apt  to  derive  from  the  iron  pre- 
sent in  the  sand  he  employs.  To  him  it 
is  of  great  consequence  to  get  a  native 
manganese  containing  as  little  iron  oxide 
as  possible;  since  in  fact  the  color  or 
limpidity  of  his  product  will  depend  alto- 
gether upon  that  circumstance. 

Sulphate  of  manganese  has  been  of 
late  years  introduced  into  calico-printing, 
to  give  a  chocolate  or  bronze  impression. 
It  is  easily  formed  by  heating  the  black 
oxide,  mixed  with  a  little  ground  coal, 
with  sulphuric  acid.  (See  Calico-Pbint- 
ns'G.) 

The  peroxide  of  manganese  is  used  also 
in  the  formation  of  glass  pastes,  and  in 
making  the  black  enamel  of  pottery. 

MANGLE  is  a  machine  for  pressing 
heavy  linen  after  washing.  The  linen, 
&c,  is  wrapped  round  rollers,  and  these 
ure  passed,  backward  and  forward,  under 
a  heavily-loaded  case.  The  best  are 
those  in  which  the  winch  turns  but  one 
way,  the  motion  being  reversed  in  the 
geer  when  the  case  has  run  home. 

An  improved  mangle  has  been  made 
by  which  linen  may  be  both  ironed  and 
mangled  at  the  same  time.  It  is  worked 
by  a  moving  table,  which  passes  under  a 
pressure  of  l£  ton;  and  the  operation 
may  be  performed  by  a  child  of  eight  or 
nine  years  old.  The  machine  docs  not 
occupy  a  space  of  more  than  eight  super- 
ficial feet,  and  the  weight  of  the  whole  is 
not  more  than  2  cwt.  A  good  mangle  is 
now  made  by  three  heavy  rollers  laid 
vertically:  a  winch  handle  works  the  in- 
termediate one,  and  the  upper  is  pressed 
down  by  a  screw  to  any  desired  amount 
of  pressure. 


344 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[man 


MANGO.  A  celebrated  fruit,  now 
produced  in  most  of  the  tropical  parts  of 
the  globe.  The  taste  is  delicious,  slightly 
acid,  and  yields  only  to  the  mangosteen. 
It  attains  the  height  of  30  or  40  feet,  has 
a  rapid  growth,  and  is  very  productive. 
The  fruit  is  kidney-shaped,  subject  how- 
ever to  a  good  deal  of  variation  in  size, 
form,  and  color,  and  contains  a  large  flat- 
tened stone.  More  than  80  varieties  are 
cultivated,  some  of  which  are  very  beau- 
tiful, and  diffuse  a  delightful  perfume. 

The  mango  has  been  fruited  both  in 
France  and  "England.  If  a  stove,  or  part 
of  a  stove,  were  fitted  up  for  them,  there 
can  be  no  doubt  but  that  the  mango  may 
be  had  on  the  table  as  easily  as  the  pine- 

MANGOSTEEN.  A  far-famed  fruit, 
ia  the  product  of  a  middling-sized  and 
beautiful  tree,  the  garcinia  mangostana, 
and  was  originally  brought  from  the  Mo- 
lucca islands,  but  is  now  cultivated  in 
many  parts  of  the  East  Indies.  It  is,  on 
all  hands,  admitted  to  be  the  most  de- 
licious, as  well  as  the  most  wholesome,  of 
all  known  fruits ;  it  requires  the  same 
treatment  as  the  mango.  To  these  may 
be  added  the  jambosteen,  rambosteen, 
and  decku  ;  they  are  natives  of  the  Orien- 
tal Archipelago,  and,  when  obtained, 
might  be  cultivated  along  with  the  pre- 
ceding in  the  Southern  States. 

MAN1HOT.— Two  kinds  are  cultivat- 
ed in  the  W.  Indies,  the  sweet  cassada  of 
Evoivne's  Jamaica,  and  Manihot  Aim, 
whose  root  is  of  a  white  color,  and  free 
from  deleterious  qualities.  The  bitter 
cassada,  or  manioc  has  a  yellowish  root, 
and  abounds  in  a  poisonous  juice.  By 
various  processes,  by  bruising  between 
atones,  by  a  coarse  rasp,  or  by  a  mill,  the 
root  of  the  manioc  is  broken  into  small 
pieces,  then  put  into  a  sack,  and  subject- 
ed to  a  heavy  pressure,  by  which  all  the 
juice  is  expressed.  What  remains  is  cas- 
sava, or  cassada,  which,  if  properly  dried, 
is  capable  of  being  preserved  for  a  great 
length  of  time.  In  French  Guiana,  ac- 
cording to  Aublet,  cassava  flour  is  made 
by  toasting  the  grated  root  over  the  fire, 
in  which  state,  if  kept  from  humidity,  it 
will  continue  good  for  20  years.  Cassava- 
cake,  or  cassava-root,  is  the  meal,  or  the 
grated,  expressed,  and  dried  root  of  the 
manioc,  pounded  in  a  mortar,  passed 
through  a  coarse  sieve,  and  baked  on  flat 
circular  iron  plates,  fixed  in  a  stove.  The 
particles  of  meal  are  united  by  the  heat ; 
and,  when  thoroughly  baked  in  this 
manner,  from  cakes,  which  are  sold  at 
the  markets,  and  universally  esteemed  as 


wholesome  kind  of  bread.  The  Spaniards, 
when  they  first  discovered  the  West  In- 
dies, found  this  in  general  use  among  the 
native  Indians,  who  called  it  cazabbi, 
and  by  whom  it  was  preferred  to  every 
other  kind  of  bread,  on  account  of  its 
easy  digestion,  the  facility  with  which  it 
was  cultivated,  and  its  prodigious  in- 
crease. Again,  in  Guiana,  cipipa  is  an- 
other preparation  from  this  plant,  and  is 
the  name  given  to  a  very  fine  and  white 
fecnla,  which,  according  to  Aublet,  is  de- 
rived from  the  expressed  juice  of  the 
roots,  which  is  decanted  off,  and  suffered 
to  rest  for  some  time,  when  it  deposits 
an  amylaceous  substance,  which  requires 
repeated  washing. 

The  root  of  the  manioc  is  also  the  basis 
of  several  kinds  of  fermented  liquors; 
and  an  excellent  condiment  for  seasoning 
meats,  called  cabion  or  capion,  is  prepar- 
ed from  the  juice,  and  saia  to  sharpen  the 
appetite.  The  leaves,  beaten  and  boiled, 
are  eaten  after  the  manner  of  spinach ; 
and  the  fresh  root  is  employed  in  nealing 
ulcers.  The  expression  of  the  juice  from 
the  root  deprives  the  latter  of  all  its  de- 
leterious properties  :  and  that  the  appli- 
cation of  heat  to  these  juices  renders 
their  residue  also  wholesome  and  nou- 
rishing. And  whilst  cassava-bread  is,  as 
Sloane  says,  in  the  most  general  demand 
of  any  provision  all  over  the  West  Indies, 
and  is  employed  to  victual  ships,  the  use 
of  tapioca  is  still  more  extended,  and 
throughout  Europe  is  employed  for  the 
same  purposes  as  sago  and  arrow-root. 

MANNA  IN  TEARS,  is  that  which 
flows  spontaneously  from  manna  ash- 
trees,  and  dries  upon  the  bark; 'mostly 
the  fraxinus  rotnndifolia ;  but,  in  less 
quantity,  by  the  F.  ornus,  F.  excelsior, 
and  F.  parvifolia ;  also  by  the  plum,  oak, 
and  willow. — Make  Manna,  hangs  in 
stalactites  from  straw,  &c,  bound  round 
a  tree  in  June  and  July.  Manna  is  laxa- 
tive, in  a  dose  of  2  scrs.  to  i  oz.  for  chil- 
dren or  double  for  adults,  in  milk  or  any 
other  liquid.  Common  Manna  flows  from 
incisions,  made  after  the  1st  of  August, 
in  Sicily. — Briangon  Manna  is  found  on 
the  leaves  of  the  larch,  in  Dauphiny. — 
Arabian  Manna,  the  Manna  of  Moses,  is 
exuded,  in  June,  from  a  species  of  tam- 
arisk, growing  in  the  desert,  and  only 
collected  at  early  dawn,  as  it  melts  in  the 
heat  of  the  day,  and  runs  into  the  Band. 
It  is  white  and  solid,  if  kept  cool,  but 
melts  by  the  heat  of  the  hand.  It  is 
sweet,  aromatic,  and  very  scarce. — Per- 
sian Manna  exudes  from  the  Hedysarum 
|  alhagi,  and  is  used  as  a  purgative. 


man] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


345 


MANURES.  Substances  added  to  the 
soil,  with  a  view  of  accelerating  vegeta- 
tion, and  increasing  the  production  of  the 
crops.  Animal,  vegetable,  and  mineral 
substances  are  used  for  this  purpose. 
Decomposing  animal  matter  of  any  Kind 
forms  one  of  the  most  powerful  manures, 
and  in  many  instances  accelerates  the 
decay  and  decomposition  of  inert  vege- 
table matters  mixed  with  it;  as  in  the 
mixture  of  dung  and  straw  which  forms 
the  common  offal  of  stables.  All  animal 
excrements  are  also  powerful  manures, 
and,  when  duly  applied  to  the  soil,  soon 
exhibit  their  influence  by  the  luxuriance 
of  the  crop.  It,  however,  often  happens, 
in  respect  to  esculent  vegetables,  that 
their  quality  is  deteriorated,  and  that 
they  acquire  a  coarse  and  rank  flavor  if 
over-manured  ;  as  is  the  case  with  much 
of  the  produce  of  the  market-gardens 
near  large  cities,  where  in  consequence  of 
the  vicinity,  manure  is  abundant,  and 
luxuriant  and  fine-looking  vegetables  in 
great  request  for  the  table. 

In  all  cases  where  animal  manures  are 
used,  care  should  be  taken  that  they  are 
brought  into  action  upon  the  soil  as  soon 
as  they  begin  to  decompose,  or  as  soon 
as  possible  afterwards,  and  not  suffered 
to  rot,  and  exhale  their  best  constituent 

Sarts  while  lying  in  the  farm-yard.  The 
rainings  and  the  exhalations  of  a  com- 
mon dung-heap  contain  its  most  effective 
ingredients ;  and  these  are  often  suffered 
to  go  to  waste,  or  to  contaminate  the  air 
and  collect  in  pools  of  filth.  The  fresh 
and  the  old  manure  of  this  decomposi- 
tion arc  known  to  farmers  under  the 
terms  long  and  short  dung :  the  advan- 
tages and  economy  of  the  former,  when 
properly  applied,  cannot  be  doubted. 
Those  animal  manures  which  are  slow  of 
decompositon  are  most  durable,  and  gen- 
erally most  effective  in  their  operation. 
Of  these,  the  best  is  ground  bones,  the 
animal  part  of  which  is  very  gradually 
dissolved  out  by  moisture ;  so  that  their 
effect  is  long-continued,  and  their  earthy 
matter  is  also,  probably,  beneficial,  at 
least  to  many  crops.  Vegetable  manures 
are  often  very  effective,  especially  as  in 
the  case  of  ploughing  in  a  green  crop, 
where  all  the  soluble  matters  are  brought 
into  action ;  and  inert  vegetable  sub- 
stances may  be  rendered  active  by  mix- 
ture with  those  which  easily  putrify,  or 
with  animal  matter.  Some  vegetables, 
such  as  cabbages  and  many  other  cruci- 
form plants,  approximate  to  animal  mat- 
ter in  their  composition,  and  are  propor- 
tionately good  manures.  Mineral  man- 
15* 


ures  act  in  two  ways :  either  by  their 
causticity,  as  is  the  case  with  quicklime, 
by  v/hich  they  decompose  most  organic 
bodies,  such  as  roots,  fibres,  &c,  and 
render  them  soluble  and  nutritious  to  the 
growing  crop ;  or  they  alter  the  texture 
of  the  soil.  Thus,  sand  may  be  called  a 
manure  for  clayey  lands,  and  clay  and 
loam  for  those  that  are  sandy.  Upon  the 
same  principle,  stiff  soils  are  improved 
by  paring  and  burning,  by  which  a 
superficial  sandiness  is  produced,  and  the 
texture  of  the  soil  rendered  more  appro- 
priate for  vegetation. 

The  principle  on  which  manures  act 
has  only  been  fully  understood  since 
chemistry  has  lent  its  aid  to  agriculture. 
When  crops  grow  upon  soils  they  re- 
move a  certain  portion  of  mineral  mat- 
ters, which,  if  not  replaced,  leave  that 
ground  deficient,  and  a  constant  course 
of  cropping  with  one  plant  will  remove 
nearly,  if  not  all,  the  substances  which 
the  plant  requires  out  of  the  soil.  The 
crop  will  every  year  diminish,  till  ulti- 
mately it  does  not  return  its  seed.  Such 
is  the  case  of  Virginia  with  tobacco  cul- 
tivation, and  many  parts  of  the  south 
with  cane  culture.  Trie  ground  so  treat- 
ed is  not  perfectly  barren,  for  it  will  grow 
other  crops ;  and  if  these  be  planted 
and  removed  without  any  addition  to  the 
ground,  the  latter  becomes  permanently 
sterile.  This  is  the  condition  of  much 
of  the  land  in  Europe,  which  is  cultivated 
by  those  who  have  no  real  interest  in  the 
good  of  the  soil;  and  it  is  the  condition 
toward  which  much  of  the  land  of  New 
England  and  the  Atlantic  States  is  ap- 
proaching from  ignorance  and  careless 
iarming.  Now,  to  restore  those  mineral 
substances,  which  have  been  removed 
by  a  crop  or  a  rotation,  is  the  object  of 
manuring,  and  a  manure  ought  always 
be  looked  upon  as  certain  substances 
added  for  the  supply  of  the  wants  of  the 
crop.  The  soil  does  not  require  addition 
or  improvement,  except  so  far  as  it  min- 
isters to  the  wants  of  the  plant.  Hence 
the  folly  of  using  only  one  variety  of 
manure  for  various  kinds  of  crops.  All 
plants  do  not  require  lime ;  hence  con- 
stant liming  is  unnecessary,  and  constant 
farm  manure,  without  other  additions,  is 
equally  absurd.  The  manure  should  con- 
tain those  things  which  the  crop  or  the  ro- 
tation requires.  It  should  contain  the  ex- 
act chemical  salts,  and  sufficient  to  supply 
the  deficiency  which  the  crop  produces. 
To  know  what  manures  to  apply,  it  is 
necessary  to  know  what  minerals  plants 
abstract,  and  this  is  learned  by  a  chemical 


346 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[man 


analysis  of  the  crop.  There  are  now  an- 
alyses made  of  most  of  the  cultivated 
plants,  from  which  data  special  manures- 
may  be  deduced — the  application  <  of 
which  is  more  certain  and  economical 
than  the  old  fashioned  mode.  This  sub- 
ject of  special  manures  is  but  in  its  in- 
fancy ;  and  analyses  of  American  plants, 
made  by  trustworthy  chemists,  are  ex- 
tensively required,  until  which  be  done 
little  absolute  exactitude  can  be  obtained. 
It  is  in  this  line  that  a  bureau  of  agricul- 
ture at  Washington  could  act  most  effici- 
ently. Plants  do  not  remove  more  than 
14  elements  out  of  the  soil,  and,  there- 
fore, comparatively  few  substances  are 
required  to  be  added  as  manure.  These 
are  silica,  lime,  magnesia,  oxide  of  iron, 
potash,  soda,  ammonia,  sulphuric,  phos- 
phoric, and  carbonic  acids.  To  supply 
these  in  the  cheapest  and  most  effective 
forms  is  the  object  of  the  farmer.  Silica 
always  exists  in  ground  in  sufficient 
quantity.  Lime  is  added  either  as  caustic 
lime,  or  as  compost  with  farm  sweepings, 
or  as  marl,  which  is  an  impure  carbonate, 
with  a  little  phosphate  and  sulphate. 
Gypsum  supplies  lime  with  sulphuric 
acid,  and  bones  or  phosphorite  supplies 
lime  with  phosphoric  acid,  as  phospnate 
of  lime.  Guano  also  supplies  phosphate 
of  lime,  but  the  chief  object  of  guano  is 
to  supply  ammonia  by  decomposition. 
The  value  of  bones  is  much  increased  by 
acting  on  it  with  sulphuric  acid,  forming 
what  is  called  dissolved  bones.  The  use 
of  bones  and  guano  are  the  two  greatest 
modern  improvements  in  agriculture. 
Potash  is  absolutely  required  by  some 
plants,  as  maize  and  oats,  and  may  be 
added  in  the  form  of  pearlash  or  nitre. 
Cow-dung  contains  salts  of  potash,  and 
much  of  it  depends  upon  the  presence  of 
the  potash.  Some  plants  prefer  potash 
when  they  can  have  a  selection,  otherwise 
they  appear  to  thrive  just  as  well  on 
soda.  This  fact  of  substitution  is  not 
fully  understood  in  agriculture ;  in  prac- 
tice we  do  know  that  one  substance  will 
replace  another  in  the  plant  without  in- 
jury. This  resembles  isomorphism  in 
minerals  very  much.  Potash  and  soda 
have  a  remarkable  effect  in  developing 
the  leaf  and  other  green  parts  of  plants. 
The  nitrates  of  potash  and  soda  exert  a 
wonderful  influence  in  this  way.  It  is  not 
easy  to  say  how  much  is  due  to  the  acid, 
and  how  much  to  the  alkaline  element. 
Unleached  ashes  is  always  preferable  to 
the  leached.  Ammonia  is  the  most  pow- 
erful stimulant  to  all  plants,  and  is  requir- 
ed by  them.  The  salts  of  ammonia  are  gen- 


erally too  expensive,  and  hence  the  use 
of  those  substances  which  supply  it  by 
decomposition.  Animal  matters,  urine, 
excrement,  wool,  hair,  horn,  guano,  and 
the  gelatine  in  bones  all  act  in  this  way, 
and  that  is  the  most  efficient  manure 
which  decomposes  most  readily,  and 
affords  the  ammonia  most  quickly. 
Night-soil  is  a  most  powerful  manure, 
but  it  is  disliked  on  account  of  its  un- 
pleasant odor — this,  however,  is  gotten 
rid  of  by  mixing  it  with  fresh  burned 
charcoal.  Fish,  along  shore,  forms  a  most 
valuable  manure  for  corn  or  potatoes,  and 
is  fully  equal  to  guano.  Sea-weed  is  ben- 
eficial on  account  of  the  large  quantity  of 
saline  matters  which  it  adds  to  the 
ground. 

MANUSCRIPTS.  (Lat.  manu  scrip- 
turn,  written  by  the  hand.)  Literally, 
writings  of  any  kind,  whether  on  paper 
or  any  other  material,  in  contradistinction 
to  such  as  are  printed.  Books  were  ge- 
nerally written  upon  vellum,  after  the 
papyrus  used  in  classical  times  had  be- 
come obsolete,  until  the  general  introduc- 
tion of  paper  made  from  rags,  about  the 
15th  century  after  Christ ;  and  the  finest 
and  whitest  vellum  is  generally  indi- 
cative of  great  age  in  a  manuscript. 
The  dearness  of  this  material  gave  rise 
to  the  practice  of  using  old  manuscript 
books  on  which  the  writing  had  been 
erased,  and  also  to  that  of  abbrevia- 
tions. These  were  carried  to  excess  in 
the  12th  century,  and  from  that  time  un- 
til the  invention  of  printing ;  and  for  a 
long  period  subsequent  to  that  invention, 
abbreviations  were  still  in  common  use  : 
in  Greek  printing  they  were  usual  until 
within  the  last  "fifty  years.  Of  Latin 
MSS.,  those  prior  to  the  reign  of  Charle- 
magne (A.  D.  800)  are  considered  ancient. 
Manuscripts  of  the  early  classical  age 
were  written  on  sheets  rolled  together. 
Illuminated  manuscripts  are  such  as  are 
embellished  with  ornaments,  drawings, 
emblematical  figures,  &c.  illustrative  of 
the  text.  This  practice  was  introduced  at 
a  very  early  period  ;  for  we  find  the  works 
of  Varro,  Pomponius,  Atticus,  and  others, 
adorned  by  illuminations.  But  it  was 
chiefly  employed  in  the  breviaries  and 
prayer-books  of  the  early  Christian  church. 
The  colors  most  employed  for  this  pur- 
pose were  gold  and  azure.  Illuminations 
were  in  a  high  state  of  perfection  between 
the  5th  and  10th  centuries ;  after  which 
they  seem  to  have  partaken  of  the  barba- 
rism of  the  middle  ages,  which  threw 
their  chilling  influence  over  every  de- 
scription of  art.    On  the  revival  of  the 


map] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


347 


arts  in  the  15th  and  16th  centuries  many 
excellent  performances  were  produced: 
but  the  art  did  not  take  deep  root,  ana 
we  believe  the  last  specimen  of  illumina- 
tion executed  in  England  was  Cardinal 
"Wolsey's  Lectionary,  at  Christ  Church, 
Oxford. 

MAP.  (Lat.  mappa.)  A  delineation 
of  some  portion  of  the  surface  of  the 
sphere  (terrestrial  or  celestial)  on  a  plane. 
Terrestrial  maps  are  geographic  or  hydro- 
graphic.  A  map  representing  a  small  ex- 
tent of  country  is  called  a  topographical 
map. 

Terrestrial  Maps..  The  object  of  a  ter- 
restrial map  is  to  exhibit  the  boundaries 
of  countries  and  the  relative  positions  of 
their  several  parts.  A  perfect  represen- 
tation of  a  country  should  present  all  its 
parts,  not  only  in  their  true  relative  posi- 
tions, but  also  in  their  just  proportions. 
This  may  be  accurately  done  on  a  globe  ; 
but  as  the  earth's  surface  is  spherical,  it 
is  impossible  to  represent  any  considera- 
ble portion  of  it  on  a  plane  so  that  the  dis- 
tances of  places  shall  retain  the  same  pro- 
portions which  they  have  on  the  sphere, 
and  geographers  have  accordingly  had  re- 
course to  various  methods  of  delineations, 
all  of  which  have  their  peculiar  advanta- 
ges in  particular  cases. 

One  method  is  to  represent  the  points 
and  lines  of  the  sphere  according  to  the 
rules  of  perspective,  or  as  they  would  ap- 
pear to  the  eye,  having  some  assigned 
position  relatively  to  the  sphere  and  the 
plane  of  representation.  This  method 
gives  rise  to  the  different  modes  of  pro- 
jecting the  sphere,  of  which  the  three 
principal  are  the  orthographic,  the  stere- 
ograph ic,  and  the  central.  The  method 
of  projection  answers  very  well  when  the 
surface  to  be  represented  is  small,  and 
the  eye  is  placed  perpendicularly  over  it ; 
but  when  it  embraces  a  considerable  por- 
tion of  the  sphere,  the  parts  near  the  ex- 
tremities of  the  map  are  much  distorted. 

A  second  method  is  to  suppose  the  sur- 
face to  be  represented  to  be  a  portion  of 
the  surface  of  a  cone,  whose  vertex  is 
somewhere  in  the  polar  axis  produced, 
and  which  either  touches  the  sphere  at 
the  middle  latitude  of  the  surface  to  be 
represented,  or  falls  within  the  sphere  at 
the  middle  latitude,  and  without  it  at  the 
extreme  parallels.  The  conical  surface  is 
then  supposed  to  be  developed  on  a  plane 
(which  it  admits  of  being) ;  whence  this 
method  is  called  the  method  of  develop- 
ment. Of  this  method  there  are  various 
modifications  :  as  that  of  Murdoch,  who 
Bupposes  the  side  of  the  cone  to  be  paral- 


lel to  the  tangent  of  the  meridian  at  tho 
middle  latitude,  but  to  penetrate  the  sur- 
face of  the  sphere  between  the  middle 
latitude  and  the  extremities  of  the  pro- 
jected arc ;  that  of  De  Lisle,  who  assum- 
ed the  cone  such  as  to  intersect  the  sphere 
in  the  two  parallels  equally  distant  from 
the  extreme  and  middle  latitudes  ;  that  of 
Euler,  who  placed  the  apex  of  the  cone  at 
a  determinate  distance  beyond  the  pole. 

A  third  method  is  to  lay  down  the 
points  on  the  map  according  to  some  as- 
sumed mathematical  law,  the  condition 
to  be  fulfilled  being  that  the  parts  of  the 
spherical  surface  to  be  represented,  and 
their  representations  on  the  map,  shall 
be  similar  in  their  small  elements.  Of 
such  methods  the  best  known  is  Merca- 
tor's  Chart  (which,  however,  may  be  pro- 
duced also  by  development),  in  which  the 
meridians  are  equidistant,  parallel,straight 
lines,  and  the  parallels  of  latitude  are  also 
straight  lines  perpendicular  to  the  meri- 
dians ;  but  of  which  the  distances  from 
each  other  increase  in  going  from  the 
equator  in  such  a  proportion  as  always  to 
show  the  true  bearings  of  places  from  one 
another. 

Celestial  Maps. — For  the  construction  of 
his  maps  of  the  stars,  the  astronomer 
Flamstead  adapted  the  following  method : 
All  the  parallels  on  the  sphere  are  repre- 
sented by  straight  lines,  and  likewise  one 
of  the  meridians  ;  namelv,   that  which 

?  asses  through  the  middle  of  the  map. 
'he  parallels  which  are  all  perpendicular 
to  this  meridian  have  the  same  relative 
lengths  as  on  the  sphere,  and  consequent- 
ly the  degrees  of  longitude  are  represent- 
ed in  their  just  proportions;  that  is,  are 
froportional  to  the  cosine  of  the  latitude. 
f,  therefore,  the  parallels  be  each  divided 
into  the  same  number  of  equal  parts,  a 
curve  line  drawn  through  the  points  of 
division  will  represent  the  meridians. 
By  this  method,  any  distance  in  the  di- 
rection of  the  parallels  is  equal  to  the  cor- 
responding distance  on  the  sphere ;  but 
it  is  evident  that  the  map  is  much  dis- 
torted towards  the  extremities,  in  conse- 
quence of  the  oblique  directions  of  the 
meridians.  Flamstead's  method  is  some- 
times used  in  geography  for  representing 
countries  which  he  on  both  sides  of  the 
equator,  in  which  case  the  distortion  is 
less.  A  modification  of  it,  which  consists 
in  substituting  arcs  of  circles  for  the 
straight  lines  representing  the  meridians, 
whereby  their  obliquity  is  diminished,  is 
extensively  employed  in  the  construction 
of  maps.  'The  Society  for  the  Diffusion  of 
Useful  Knowledge  has  adopted  the  gno- 


348 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mar 


monic  projection  for  laying  down  their 
maps  of  the  stars. 

MAPLE.  A  genus  of  plants,  consist- 
ing of  trees  or  arborescent  shrubs. 
Twenty-seven  species  are  known,  of 
which  12  inhabit  North  America,  6  are 
found  in  Europe,  6  in  Japan,  and  the  re- 
mainder in  Asia. 

The  sugar-maple  {A.  saccharinum)  is 
one  of  the  most  valuable.  It  grows  be- 
tween Lat.  42°  and  48°  N.  and  nourishes  j 
in  cold  and  moist  situations :  in  all  N. 
England,  Western  New  York,  Canada, 
L.  Superior  shores,  and  down  the  Alle- 
ghanies,  it  is  met  with.  A  variety  with  un- 
dulations, called  birds-eye  maple,  is  much 
used  in  furniture.  The  black  sugar  ma- 
ple {A.  Nigrum)  is  found  in  Ohio  and  far- 
ther South. 

Besides  the  sugar  which  is  obtained 
from  the  sap,  the  wood  affords  excellent 
fuel ;  and,  from  the  ashes  are  procured 
four-fifths  of  the  potash  which  forms  such 
an  important  item  of  commerce.    The  su- 

far  is  superior  in  quality  to  the  common 
rown  sugar  of  the  West  Indies,  and, 
when  refined,  equals  the  finest  in  beauty. 
A  single  tree  of  this  species  will  yield  5  or 
6  lbs.  of  sugar. 

Sugar  Mapfe,  (acer  saccharinum,)  Syca- 
more, and  Norway  Maple. — The  sap  of 
these  trees,  as  well  as  that  of  the  common 
maple,  is  used  for  making  sugar  and 
wine.  The  wood  of  the  European  maple 
is  employed  in  making  violins. 

MARANTA  INDICA,  is  the  plant 
whose  roots  vield  Indian  arrow-root. 

MARBLES  FOR  TOYS.    These  well- 
known  articles  are  made  in  great  quanti- 
ties, to  serve  in  the  games  of  children  ; 
some  are  formed  of  potter's  clay,  covered 
with  a  glaze,  and  burnt  in  a  proper  fur- 
nace ;  others  are  made  of  marble  and  ala-  j 
baster,  but  chiefly  of  a  species  of  very 
hard    calcareous     stone,    found    in    the 
neighborhood  of  Cobourg,    in    Saxony,  j 
These  stones  are  first  broken  into  square 
blocks  by  means  of  a  hammer,  and  are  fi-  j 
nally  rounded  into  spheres  or  small  ball3  j 
by  a  mill.     In  order  to  effect  this,  they  are  J 

S laced,  from  100  to  150  at  a  time,  upon  a  j 
xed  slab  of  stone,  having  a  number  of 
concentric  circular   grooves  or   furrows  I 
made  in  its   flat    surface.     Above  this 
stone,  another  flat  slab,  or  block  of  oak,  ! 
of  the  same  diameter,  is  supported  by 
means  of  a  lever,  and  turned  round  by 
the  power  of  the  mill.    During  the  rota- 
tory action  of  this  mill,  small  threads  of  ; 
water  are  made  to  enter  each  of  the  con- 
centric grooves,  which  favor  the  rounding 
and  polishing  of  the  balls,  and  prevent  | 


the  wood  from  heating.  The  operation 
of  each  of  the  quantities  abovementioned 
lasts  for  a  quarter  of  an  hour,  and  the 
balls,  or  marbles,  become  perfectly  sphe- 
rical and  fit  for  sale.  Immense  quantities 
of  them  are  exported  to  India  and  China. 
A  mill,  with  three  turning-blocks,  will 
manufacture  60,000  marbles  a-week. 

MARBLE.  This  title  embraces  such 
of  the  primitive,  transition,  and  purer 
compact  limestones  of  secondary  forma- 
tion, as  may  be  quarried  in  solid  blocks 
without  fissures,  and  are  susceptible  of  a 
fine  polished  surface.  The  finer  the 
white,  or  more  beautifully  variegated  the 
colors  of  the  stone,  the  more  valuable. 
ceteris  paribus,  is  the  marble.  Its  general 
characters  are  the  following  : — 

Marble  effervesces  with  acids;  affords 

auicklime  by  calcination ;  has  a  conchoi- 
al  scaly  fracture ;  is  translucent  only  on 
the  very  edges  ;  is  easily  scratched  by  the 
knife  ;  has  a  spec.  grav.  of  2#7  ;  admits 
of  being  sawn  into  slabs,  and  receives  a 
brilliant  polish.  These  qualities  occur 
united  in  only  three  principal  varieties  of 
limestone :  1,  in  the  saccharoid  limestone, . 
so  called  from  its  fine  granular  texture  re- 
sembling that  of  loaf  sugar,  and  which 
constitutes  modern  statuary  marble,  like 
that  of  Carrara ;  2,  in  the  foliated  lime- 
stone, consisting  of  a  multitude  of  small 
facets  formed  of  little  plates  applied  to 
one  another  in  every  possible  direction, 
constituting  the  antique  statuary  marble, 
like  that  of  Paros ;  3,  in  many  of  the 
transition  and  carboniferous,  or  encrmitic 
limestones,  subordinate  to  the  coal  for- 
mation. 

The  saccharoid  and  lamellar,  or  statuary 
marbles,  belong  entirely  to  primitive  and 
transition  districts.  The  greater  part  of 
the  close-grained  colored  marbles  oelong 
also  to  the  same  geological  localities ;  and 
become  so  rare  in  the  secondary  limestone 
formations,  that  immense  tracts  of  these 
occur  without  a  single  bed  sufficiently  en- 
tire and  compact  to  constitute  a  workable 
marble. 

Marbles  abound  in  the  United  States 
both  fine-grained  and  coarse.  The  quar- 
ries in  the  neighborhood  ot  Philadelphia 
afford  a  clouded  handsome  marble  j  at 
Thomastown,  in  Maine,  a  similar  variety 
occurs.  Of  black  marble,  resembling  the 
Irish  lucullite,  there  is  an  extensive  de- 
posit at  Shoreham,  Vermont,  which  fur- 
nishes the  chief  supply  to  the  States. 
The  bed  lies  directly  on  the  shores  of  L. 
Champlain,  so  that  the  blocks  when  lifted 
can  be  transported  by  water.  Most  of  it 
goes  to  Middlebury  to  be  polished.    In 


mar] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


349 


the  neighborhood  of  this  last  town  a 
clouded  granular  marble  is  found :  a  dove- 
colored  variety  is  quarried  at  Pittsford, 
Vt.,  as  also  at  Great  Barrington  and 
Sheffield.  The  white  marble  of  Conn, 
and  Westchester,  N.  Y.,  are  too  coarse 
and  granular  for  building  purposes,  be- 
sides having  tremolite  and  other  crystals 
scattered  through  them.  Verd  antique 
exists  in  Vermont  and  Conn. :  that  from 
the  latter  State  being  most  beautiful. 
Variegated  and  shell  marbles  exist  in  the 
Western  States  ;  and  a  beautiful  conglo- 
merate (pudding  stone)  or  breccia  is 
found  at  the  base  of  the  Blue  Ridge,  Md., 
on  the  bank  of  the  Potomac,  60  miles 
above  Washington.  The  inner  columns 
of  the  Capitol  are  made  of  it. 

Of  cutting  and  polishing  marble. — 'The 
marble  saw  is  a  thin  plate  of  soft  iron, 
continually  supplied,  during  its  sawing 
motion,  with  water  and  the  sharpest  sand. 
The  sawing  of  moderate  pieces  is  per- 
formed by  hand,  but  that  of  large  slabs 
is  most  economically  done  by  a  proper 
mill. 

The  first  substance  used  in  the  polish- 
ing process  is  the  sharpest  sand,  which 
must  be  worked  with  till  the  surface  be- 
comes perfectly  flat.  Then  a  second,  and 
even  a  third  sand  of  increasing  fineness  is 
to  be  applied.  The  next  substance  is 
emery  of  progressive  degrees  of  fineness, 
after  which  tripoli  is  employed ;  and  the 
last  polish  is  given  with  tin-putty.  The 
body  with  which  the  sand  is  rubbed  upon 
the  marble,  is  usually  a  plate  of  iron ;  but 
for  the  subsequent  process,  a  plate  of  lead 
is  used  with  fine  sand  and  emery.  The 
polishing  rubbers  are  coarse  linen  cloths, 
or  bagging,  wedged  tight  into  an  iron 
planing  tool.  In  every  step  of  the  opera- 
tion, a  constant  trickling  supply  of  water 
is  required. 

MARGARIC  ACID.  The  substance 
into  which  the  margarine,  or  concrete 
portion  of  certain  oils,  is  converted  by 
the  action  of  alkalies.  It  has  a  pearly 
lustre,  and  is  insoluble  in  water  :  but 
readily  soluble  in  hot  alcohol,  which  de- 
posited it  as  the  solution  cools.  It  fuses 
at  140°,  and  reddens  litmus.  It  closely 
resembles  stealic  acid,  but  is  more  fusible. 

MARGARINE.  The  solid,  fatty  mat- 
ter of  certain  vegetable  oils,  has  been 
thus  termed  by  Lecanu,  from  its  pearly 
lustre.  The  purest  margarine  is  obtained 
from  the  concrete  portion  of  olive  oil. 

MARGAR1TIC  ACID.  A  distinctive 
term  applied  to  one  of  the  fatty  acids 
which  result  from  the  saponification  of 
castor  oil.    By  the  same  process,  this  oil 


also  yields  the  ricinic  and  the  e»aiodic 
acids. 

MARGARONE.  When  margar  z  acid 
is  mixed  with  quicklime  and  distilled,  a 
peculiar  fatty  product,  which  crystallizes 
in  pearly  scales  is  obtained,  which  has 
been  distinguished  by  the  above  term 
from  other  analagous  substances. 

MARGIN  in  Printing,  is  the  arrange- 
ment of  the  pages  in  a  sheet  at  proper  dis- 
tances from  each  other,  according  to  the 
size  of  the  paper ;  so  that  when  the  sheet  is 
printed  and  folded,  the  border  of  white 
paper  round  them  shall  be  regular  and 
uniform  in  every  leaf  in  the  book. 

MARGIN  OF   A   COURSE.     In  Ar 
chitecture,  that  part  of  the  upper  side  of 
a  course  of  slates  which  appears  uncov- 
ered by  the  next  superior  course. 

MARINE  GLUE  is  made  by  mixing 
solutions  of  india  rubber  and  shellac  in 
coal-tar  naptha,  and  evaporating  the  mix- 
ture :  it  is  melted  when  required  to  be 
used. 

MARL,  is  compact  limestone  and 
argillaceous  matter,  and  essentially  com- 
posed of  carbonate  of  lime  and  clay,  in 
various  proportions.  Marl  frequently 
contains  sand  and  other  foreign  ingredi- 
ents. It  occurs  in  masses,  either  com- 
pact, or  possessing  a  slaty  structure.  All 
solid  marl  crumbles  by  exposure  to  the 
atmosphere,  and  it  crumbles  more  easil\, 
or  forms  a  more  tenacious  paste,  in  pro- 
portion as  it  is  more  argillaceous.  All 
marls  effervesce  with  acids,  sometimes 
very  briskly  and  sometimes  feebly,  accor- 
ding to  their  solidity  and  the  proportion 
of  carbonate  of  lime,  which  may  vary 
from  25  to  80  per  cent.  Earthy  marl, 
like  the  indurated,  may  be  either  calca- 
reous or  argillaceous.  It  sometimes 
greatly  resembles  clay,  but  may  be  dis- 
tinguished by  its  effervescence  in  acids. 
Marl  is  found  associated  with  compact 
limestone,  chalk,  gypsum,  or  with  sand 
or  clay,  and  contains  various  organic  re- 
mains, as  shells,  fish,  bones  of  birds  and 
of  quadrupeds,  and  sometimes  vegeta- 
bles. Its  most  general  use  is  as  a  ma- 
nure, and  whether  a  calcareous  or  an  ar- 
gillaceous marl  will  be  more  suitable  to 
a  given  soil,  may  be  determined  by  its 
tenacity  or  looseness,  moisture  or  dry- 
ness. 

Loam  is  sand  and  clay,  marl  is  lime- 
stone and  clay  ;  and  the  more  lime  the 
better  as  manure,  and  the  less  the  better 
for  brick-making. 

The  composition  of  marl  varies  in 
proportion  to  its  origin.  Some  of  the 
marls  in  western  New  York  are  gypsum 


350 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mat 


containing  20  per  cent,  of  plaster.  Al- 
most all  marls  contain  phosphate  of 
lime,  sometimes  as  much  as  2  per  cent. 
It  is  a  valuable  dressing  for  land,  but  it 
should  be  dug  out  and  frosted  previously 
to  laying  on. 

MASSICOT.    Yellow  oxide  of  lead. 

MAST.  A  long  piece  or  system  of 
pieces  of  timber,  placed  nearly  perpen- 
dicular to  the  keel  of  a  vessel  to  support 
the  yards  or  gaffs  on  which  the  sails  are 
extended.     When  the  mast  is  one  entire 

Eiece,  it  is  called  &  pole-mast ;  but  in  all 
irger  vessels  it  is  composed  of  several 
lengths,  called  lower,  top,  and  top-gallant 
mast :  sometimes  a  fourth,  called  a  royal 
mast. 

The  method  of  supporting  each  mast 
on  the  one  next  below  it  is  peculiar.  On 
the  sides  of  the  lower  mast,  some  feet 
below  the  head,  are  placed  cheeks  :  on 
these  are  fixed  horizontally  two  short 
pieces  of  wood,  fore  and  aft,  called  trestle 
trees.  Across  these  at  right  angles  are 
laid,  before  and  abaft  the  mast,  two  or 
more  longer  and  lighter  pieces,  called  cross 
trees,  which  give  the  name  to  the  entire 
system.  On  the  mast  head  itself  is  a  cap. 
The  topmast  being  placed  up  and  down, 
the  fore  side  of  the  lower  mast  is  swayed 
up  between  the  trestle  trees,  and  through 
the  round  or  foremast  hole  in  the  cap. 
When  raised  so  high  that  the  heel  of  the 
topmast  is  nearly  up  to  the  surface  of  the 
cross  trees,  a  piece  of  iron,  called  the  Jid,  is 
put  through  the  hole  in  the  heel  for  the 
purpose  ;  and  on  this  fid,  of  which  the 
ends  are  supported  on  the  trestle  trees, 
the  topmast  rests.  Wrhen  Added,  the 
topmast  is  stayed,  and  the  rigging  or 
shroud  set  up  to  the  dead-  eyes  in  the  ends 
of  the  cross  trees.  These  dead  eyes  pull 
from  the  lower  rigging  below,  and  thus 
the  cross  trees  serve  merely  to  extend 
the  rigging.  The  topgallant  is  supported 
in  the  same  manner  on  the  topmast. 
When  the  mast  is  to  be  taken  down,  it 
is  first  raised  to  relieve  the  fid  ;  which 
being  drawn  out,  the  mast  is  lowered. 

The  masts  are  supported  by  a  strong 
rope,  leading  forward,  called  the  stay  • 
by  others,  leading  aft  on  each  side  of  the 
&hip,  called,  in  general,  backstays  ;  and 
by  others  abreast,  called  shrouds,  and  also 
breast  backstays. 

MASTIC.  A  cement  used  lately  in 
building  for  plastering  walls.  It  is  made 
with  a  considerable  portion  of  linseed  oil 
and  gets  hard  in  a  few  days.  It  is  used 
where  expedition  is  required. 

MASTIC.  A  resin  obtained  by  making 
incisions  in  the  pistacia  leniisous  a  small 


tree  which  grows  in  the  Mediterranean 
shores  :  its  berries  yield  oil  and  the  wood 
is  used  medicinally.  It  is  used  only  in 
varnishes.  Among  the  Turks  the  women 
chew  it  to  clean  their  teeth. 

MATCHES,  Lucifer.  The  manufac- 
ture of  these  useful  little  articles  consti- 
tutes a  most  extensive  business.  In  some 
large  factories  the  wood  alone  for  the  annu- 
al consumption  approaches  in  value  $5,000. 
Lucifer  matches  are  sulphur  matches, 
to  which  a  separate  inflammable  com- 
pound is  afterwards  added.  The  primary 
coating  of  sulphur  cannot  well  he  dis- 
pensed with,  tor  the  inflammable  com- 
pound burns  too  rapidly  to  set  fire  to  the 
wood.  The  flame  produced  by  it  is  first 
transferred  to  the  sulphur  arid  then  to 
the  wood.  The  original  matches  were 
made  by  mixing  phosphorus  with  muci- 
lage at  104°,  till  it  became  a  mucilage,  to 
which  chlorate  of  potash  was  then  added. 
The  sulphured  wood  was  dipped  in  this. 
Sometimes  the  phosphorus  was  replaced 
by  sulphuret  of  antimony.  The  noise  of 
their  inflaming  was  objectionable,  and 
noiseless  matches  were  then  made  by 
replacing  the  detonating  action  of  chlorate 
of  potash,  for  the  slower  combustion  of 
nitrate  and  phosphorus.  The  general 
principle  concerned  in  the  action  of  all 
these  matches  is,  that  substances  (as  phos- 
phorus), having  a  great  affinity  for  oxy- 
gen, are  mixed  with  a  large  amount  of 
it,  condensed  into  a  small  space  fas 
in  nitre  or  chlorate  of  potash),  so  that  the 
slightest  cause  is  sufficient  to  effect  the 
combination.  The  peroxides  of  lead  and 
manganese,  which  abound  in  oxygen,  are 
often  mixed  with  the  nitre.  They  act  in 
the  same  way  when  they  have  reached 
a  red  heat. 

The  wood  is  split  by  a  perforated  me- 
tallic plate  having  a  steel  face  and 
strengthened  by  a  bell-metal  back.  A  con- 
venient size  for  these  plates  is  6  inches  X 
3,  and  one  inch  thick.  The  wood  is 
compressed  laterally  into  the  countersunk 
openings  and  forced  through  the  holes, 
which  are  slightly  countersunk  to  favor 
the  entrance  and  separation  of  the  wooden 
fibres.  The  materials  into  which  the 
matches  are  dipped  may  be  made  either 
with  or  without  sulphur.  The  latter 
kind  have  the  following  materials  enter- 
ing into  their  composition  : 

Phosphorus 4  parts 

Nitre 10  parts 

Fine  Glue 6  parts 

Red  Ochre  or  Red  Lead 5  parte 

Smalt 2  parte 

Melt  the  glue  with  water  into  a  jelly, 


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CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


351 


and  put  it  in  a  warm  place  to  melt ;  melt 
the  phosphorus  in  this  at  a  heat  of  140°, 
add  the  nitre,  then  the  lead,  and  lastly 
the  smalt,  till  the  whole  is  a  paste. 

Melt  a  little  white  wax  in  a  shallow 
vessel :  char  the  ends  of  the  wooden 
match  and  then  dip  them  in  the  wax  ; 
shake  them  dry  and  then  dip  them  in  the 
paste.  When  dry  they  will  kindle  by 
friction. 

The  ordinary  matches  consist  of  nitre 
and  chlorate  of  potash,  sulphur,  gum, 
and  phosphorus,  colored  with  the  puce 
colored  oxide  of  lead. 

The  patent  allumettes  are  made  of  the 
first  described  paste,  which  is  applied  to 
the  extremity  of  a  thin  wax  bougie. 

MATRIX.  In  Metallurgy,  the  stony  sub- 
stance  in  which  crystalline  minerals  and 
metals  are  embedded  is  frequently  termed 
their  matrix  or  gangue.  In  dye-sinking  the 
matrix  is  the  indented  mould  from  which 
impressions  are  taken  in  relief.  Type- 
founders apply  the  term  to  the  iron 
moulds  in  which  the  letters  are  cast. 

MATTER.  Substance.  Of  the  inti- 
mate nature  of  matter  the  human  facul- 
ties cannot  take  cognizance,  nor  can  data 
be  furnished,  by  observation  or  experi- 
ment, on  which  to  found  an  investiga- 
tion of  it.  All  we  know,  or  ever  can 
know  of  matter,  is  its  sensible  properties. 
Some  of  these  are  the  foundation  of 
physical  science ;  others,  of  the  different 
subordinate  sciences,  as,  for  instance,  of 
chemistry. 

Matter  is  divisible  by  abrasion,  and 
other  means,  into  small  fragments,  which, 
when  the  division  is  carried  to  any  con- 
siderable extent,  are  called  particles.  It 
is  supposed,  however,  and  many  reasons 
appear  to  justify  the  hypothesis,  that  it 
is  capable  of  reduction  into  particles 
(called  atoms)  of  particular  forms,  and 
each  class  having  its  own  proper  magni- 
tude and  peculiar  properties  ;  that  deter- 
minate numbers  of  atoms  of  one  kind 
admit  of  combination  with  some  deter- 
minate number  of  another  kind,  or  of 
several  kinds,  and  of  thereby  forming 
compounded  atoms,  having  properties  pe- 
culiar to  that  combination,  and  different 
from  the  known  properties  of  their  ele- 
mental atoms.  These  solutions  and  com- 
binations result  from  properties  inherent 
in  the  atoms  themselves  ;  but  whether 
the  simple  classes  of  atoms  that  are  be- 
lieved to  exist  are  themselves  really  pri- 
mary and  elemental  is  not  known,  and 
probably  never  can  be  with  certainty. 

In  larger  masses,  or  in  masses  of  aggre- 
gated atoms,  so  classed  that  their  peculiar 


properties  are  mutually  neutralized,  phe- 
nomena are  exhibited  which  bear  a  great 
resemblance  to  one  another  through  con- 
siderable classes  of  such  compounds, 
whose  elements  we  have  reason  to  be- 
lieve differ  very  considerably  ;  and  other 
properties  are  found  to  exist  in  all,  and 
differing  only  in  degree  or  intensity. 
These  last  are  the  subjects  of  physical  in- 
vestigation :  they  are  called  emphatically 
the  properties  of  matter  ;  and  the  laws 
of  their  mutual  influences  are  the  founda- 
tion of  mechanical  philosophy.  These 
properties  may  be  regarded  as  either  es- 
sential or  contingent.  The  essential 
properties  of  matter  are  usually  reckoned 
the  following  : 

1.  Divisibility,  or  the  property  which 
every  known  substance  possesses  of  being 
separable  into  parts,  and  these  again  into 
smaller  parts,  and  so  on  until  the  parts 
become  inappreciable  to  our  senses  ;  nor 
can  any  limit  be  placed  on  the  subdi- 
vision. 

2.  Impenetrability,  or  a  resistance  ex- 
erted by  every  body  to  the  occupation  of 
its  place  by  another.  This  resistance  is 
of  various  degrees  of  intensity,  depend- 
ent on  the  state  and  atomic  composition 
of  the  bodies  ;  but  no  two  bodies  can 
simultaneously  occcupy  the  same  place. 

3.  Porosity,  or  the  separation  of  the 
particles  or  atoms  from  each  other  by  in- 
tervals or  pores.  Every  substance  with 
which  we  are  acquainted  is  more  or  less 
porous. 

4.  Compressibility,  or  the  property  in 
virtue  of  which  the  volume  of  every 
body  may  be  contracted  into  smaller  di- 
mensions. 

Among  the  essential  properties  of  mat- 
ter may  also  be  included  extension'  and 
figure  ;  but  these  belong  also  to  space, 
and  form  the  subject  of  geometry. 

The  contingent  properties  of  matter 
are  mobility  and  weight.  Matter  in  every 
form  is  capable  of  being  moved  from  one 
place  to  another  :  and  every  substance 
gravitates  towards  the  centre  of  the 
earth.  But  motion  has  reference  to 
space,  and  weight  to  the  attraction  of 
other  matter. 

The  above  are  the  general  properties 
of  matter,  upon  which  physical  investi- 
gations depend.  There  are,  however, 
various  other  qualities  belonging  to  par- 
ticular substances,  or  to  matter  in  par- 
ticular states,  the  consideration  of  wnich 
is  important  in  mechanical  philosophy. 
Among  these  the  principal  are  elasticity, 
fluidity,  hardness,  rigidity,  solidity — for 
i  which  see  the  respective  terms. 


352 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mer 


MAUNDKIL.  In  Coal  Mines,  a  pick 
with  two  shanks. 

MEERSCHAUM:  already  alluded  to 
under  Magnesia.  It  consists,  according 
to  Klaproth,  of  silica,  41-5 ;  magnesia, 
18*25  ;  water  and  carbonic  acid,  39. 
Other  analysts  give,  silica  50,  magnesia 
25,  water  25.  It  occurs  in  veins  or  kid- 
ney-shaped nodules,  among  rocks  of  ser- 
pentine, at  Egribos,  in  the  island  of  Ne- 
gropont,  Eski-Schehir  in  Anatolia,  Brus- 
sa  at  the  foot  of  Mount  Olympus,  at  Bal- 
dissero  in  Piedmont,  in  the  serpentine 
veins  of  Cornwall,  and  at  Hoboken,  N.  J. 

When  first  dug  up,  it  is  soft,  greasy, 
and  lathers  like  soap  ;  and  is  on  that  ac- 
count used  by  the  Tartars  in  washing 
their  linen.  The  well-known  Turkey  to- 
bacco-pipes are  made  from  it,  by  a  pro- 
cess analogous  to  that  for  making  pottery 
ware.  The  bowls  of  the  pipes,  when  im- 
ported into  Germany,  are  prepared  for 
sale  by  soaking  them  first  in  tallow,  then 
in  wax,  and  finally  by  polishing  them  with 
shave-grass. 

MELLITIC  ACID,  which  is  associated 
with  alumina  in  the  mellite  or  honey- 
stone,  crystallizes  in  small  colorless 
needles,  is  without  smell,  of  a  strongly 
acid  taste,  permanent  in  the  air,  soluble 
in  water  and  alcohol,  as  also  in  boiling 
hot  concentrated  sulphuric  acid,  but  is 
decomposed  by  hot  nitric  acid,  and  con- 
sists of  50-21  carbon,  and  49*79  oxygen. 

MENACHANITE.  An  ore  of  Tita- 
nium, found  in  England. 

MEECATOE'S  CHAET,  or  PROJEC- 
TION. A  representation  of  the  sphere 
on  a  plane,  in  which  the  meridians 
are  represented  by  equidistant  parallel 
straight  lines,  and  the  parallels  of  latitude 
also  by  straight  lines  perpendicular  to  the 
meridians.  This  projection,  which  is 
universally  adopted  for  nautical  charts, 
by  reason  of  the  facilities  which  it  affords 
in  navigation  from  the  circumstance  that 
the  rhumb,  or  sailing  course  be  ween  two 
points,  is  represented  by  a  straight  line, 
was  invented  by  Gerard  Mercator  (his 
true  name  was  Kauffman,  of  which  Mer- 
cator is  the  Latin  equivalent),  a  native  of 
Rupelmonde,  in  East  Flanders,  born  in 
the  year  1512.  But,  though  Mercator 
gave  his  name  to  the  projection,  it  does 
not  appear  that  he  knew  the  law  accord- 
ing to  which  the  distance  of  the  parallels 
from  the  equator  increases.  The  true 
principles  of  the  construction  were  found 
by  Edward  Wright,  of  Caius  College, 
Cambridge,  who  explained  them  in  his 
treatise,  entitled  The  Correction  of  certain 
errors  in  Navigation,  published  in  1599, 


and  are  as  follows :  Suppose  ore  of  the 
meridians  on  the  globe  to  be  divided  into 
minutes  of  a  degree ;  one  of  these,  taken 
at  any  parallel  of  latitude,  will  be  to  a 
minute  of  longitude,  taken  on  that  par- 
allel, as  the  radius  of  the  equator  to  the 
radius  of  the  parallel ;  that  is,  as  radius 
to  the  cosine  of  the  latitude,  or  as  the 
secant  of  the  latitude  to  radius.  This 
proportion  holds  true  on  the  map  in  this 
sense,  that  if  a  minute  of  the  equator  be 
taken  as  the  unit  of  a  scale,  and  that  unit 
be  considered  as  the  radius  of  the  tables, 
then  the  representation  of  a  minute  o' 
latitude  will  be  expressed  by  the  numbei 
in  the  trigonometrical  tables  which  is  the 
secant  of  that  latitude.  Hence,  in  the 
map,  while  the  degrees  of  longitude  are 
all  equal,  the  degrees  of  latitude  marked 
on  the  meridian  form  a  scale  of  which 
the  distances  go  on  increasing  from  the 
equator  towards  the  poles,  each  being 
(approximately)  the  sum  of  the  secants 
of  all  the  minutes  of  latitude  in  the  de- 
gree. The  numbers  resulting  from  the 
addition  of  the  secants  of  the  successive 
minutes,  reckoned  from  the  equator, 
form  a  scale  of  meridional  parts,  which  is 
given  in  all  books  of  navigation.  The 
very  remarkable  property  of  this  projec- 
tion, namely,  that  the  divisions  of  the 
meridian  are  analogous  to  the  excesses  of 
the  logarithmic  tangents  of  half  the  re- 
spective latitudes  augmented  by  45°, 
above  the  logarithm  of  the  radius,  was 
discovered  by  Bond  about  the  year  1645; 
but  was  first  demonstrated  by  James 
Gregory,  in  his  Exercitationes  Mathema- 
tical, published  in  1668. 

MERCURY.  This  metal  is  found 
chiefly  in  the  state  of  suljphuret,  which  is 
decomposed  by  distillation  with  iron  or 
lime.  It  is  also  found  native.  Mercury 
is  the  only  metal  which  is  liquid  at  com- 
mon temperature ;  it  is  white  and  very 
brilliant.  It  freezes  and  assumes  a  crys- 
talline texture  at  40°  below  zero.  Its 
specific  gravity  is  13*5.  It  boils  at  660°, 
and  its  vapour  condenses  upon  cool  sur- 
faces in  minute  brilliant  globules.  It  is 
not  altered  by  exposure  to  air  at  common 
temperatures,  but  when  kept  in  vessels 
to  which  air  has  access,  at  a  temperature 
near  its  boiling  point,  it  gradually  be- 
comes converted  into  a  deep  red  crystal- 
line substance,  which  is  the  peroxide,  or 
red  oxide,  of  mercury.  When  mercury  is 
dissolved  in  cold  dilute  nitric  acid,  the 
pure  alkalis  throw  it  down  in  the  form  of 
black  protoxide.  The  same  oxide  is  also 
obtained  by  triturating  calomel  with  so- 
lution of  caustic  potash.    These  are  the 


mer] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


353 


only  definite  oxides  of  mercury.  The 
equivalent  of  this  metal  is  about  200,  and 
the  oxides,  consisting  respectively  of  1 
atom  of  mercury  and  1  of  oxygen,  and  1 
and  2  are  represented  by  200+8=208, 
and  200+16=216.  Mercury  is  represent- 
ed in  chemical  formulae  by  Hg.,  from  the 
Latin  hydrargyrum,  literally  signifying 
water  silver.  The  symbol  of  the  protox- 
ide will  then  be  (hg.+  o.),  and  of  the  per- 
oxide (hg.  +  Zo.).  Each  of  these  oxides 
combines  with  the  acids,  and  produces 
the  protosalts  and  persalts  of  mercury. 

Mercury  and  Chlorine. — There  are  two 
chlorides  of  mercury  •  a  protochloride  or 
calomel,  and  aperchloride  or  corrosive  sub- 
limate. Calomel  may  be  obtained  by 
mixing  60  parts  (1  equivalent)  of  com- 
mon salt,  or  chloride  of  sodium,  with  248 
parts  (1  equivalent)  of  protosulphate  of 
mercury,  and  exposing  the  mixture  in  a 
proper  subliming  vessel  to  a  red  heat ; 
the  chlorine  of  the  salt  combines  with 
the  mercury  of  the  sulphate  to  form  pro- 
tochloride of  mercury  (consisting  of  200 
mercury  and  36  chlorine) ;  and  the  so- 
dium of  the  salt,  uniting  with  the  oxygen 
of  the  oxide  of  mercury,  becomes  soda, 
which,  with  the  sulpnuric  acid,  forms 
sulphate  of  soda.  Calomel  may  also  be 
obtained  by  mixing  200  parts  of  mercury 
with  272  of  corrosive  sublimate,  and  sub- 
liming the  mixture.  When  thoroughly 
washed  and  levigated,  calomel  is  a  taste- 
less, white  powder  ;  its  specific  gravity  is 
7*2.  When  heated  it  acquires  a  yellow 
color ;  and  at  a  temperature  below  red- 
ness it  rises  in  dense  white  fumes,  which 
are  deposited  in  the  form  of  a  white  pow- 
der upon  cold  surfaces.  It  is  insoluble  in 
water.  When  hastily  sublimed  it  often 
becomes  a  crystalline  horny  mass,  and 
occasionally  forms  beautiful  prismatic 
crystals.  It  is  sometimes  found  native ; 
forming,  however,  a  very  rare  ore,  called, 
from  its  appearance,  horn  quicksilver. 

Perchlonde  of  mercury,  or  corrosive 
sublimate,  is  obtained  by  sublimation 
from  a  mixture  of  120  parts  of  common 
salt  (or  2  equivalents),  and  for  296  (or  1 
equivalent)  of  persulphate  of  mercury. 
It  rises  in  the  form  of  a  white  crystalline 
substance,  of  an  acrid  metallic  taste, 
highly  poisonous,  soluble  in  20  parts  of 
cold  and  in  2  of  boiling  water.  Its  spe- 
cific gravity  is  5-2.  When  heated  it  eva- 
porates in'acrid  fumes,  at  a  temperature 
below  that  required  for  the  volatilization 
of  calomel.  Corrosive  sublimate  is  a 
compound  of  1  equivalent  of  mercury 
mid  2  of  chlorine.  In  the  above  process 
for  preparing  it,  the  chlorine  is  furnished 


by  the  chloride  of  sodium,  and  sulphate 
of  soda  is  the  other  product. 

Bisulphuret  of  Mercury,  known  also  by 
the  name  of  cinnabar  or  vermilion,  is 
prepared  artificially  by  heating  together 
100  parts  of  mercury  with  about  20  of 
sulphur ;  they  form  a  black  compound, 
which,  when  strongly  heated,  rises  in  the 
form  of  a  deep  crimson-colored  sublim- 
ate ;  this,  reduced  by  long  trituration 
into  a  fine  powder,  acquires  a  brilliant 
red  color.  It  is  tasteless,  and  insoluble 
in  water  ;  it  consists  of  200  mercury  and 
32  sulphur,  or  (hg.  +  2s.)  A  black  pro- 
tosulphuret  of  mercury  (hg.+s.)  is  preci- 
pitated by  sulphuretted  hydrogen  from  a 
solution  of  the  protonitrate.  When  a 
mixture  of  equal  weights  of  finely-pow- 
dered peroxide  of  mercury  aud  Prussian 
blue  is  boiled  in  water  till  the  blue  color 
disappears,  the  solution  yields,  when  fil- 
tered and  evaporated,  a  crop  of  straw- 
colored  prismatic  crystals,  which  are  bicy- 
anuret  of  mercury  :2cy.  +  hg. 

Mercury  is  found  in  various  parts  of 
the  world.  Among  the  principal  mines 
are  those  of  Almaden,  near  Cordova,  in 
Spain  ;  Idria,  in  Carniola  ;  Wolfstein  and 
Morsfield,  in  the  Palatinate ;  Guanca 
Velica,  in  Peru.  It  is  stated  by  Dr.  A.  T. 
Thompson,  in  his  Dispensatory,  that 
most  of  the  mercury  used  in  England  is 
brought  from  Germany.  But,  whatever 
may  have  been  the  case  formerly,  this  is 
not  certainly  true  at  present.  On  the 
contrary,  of  314,286  lbs.  of  quicksilver  im- 
ported into  England  in  1831,  none  was 
brought  from  Germany :  269,558  lbs.  were 
brought  direct  from  Spain,  and  13,714  lbs. 
from  Gibraltar  •  of  the  latter  a  part  was 
derived  from  Carniola,  and  a  part  from 
Spain;  31,014  lbs.  were  brought  from 
Italy.  Only  192,310  lbs.  were  retained 
for  home  consumption  in  1831.  Quick- 
silver is  produced  in  several  of  the  pro- 
vinces ot  China.  During  the  war,  wnen 
the  intercourse  between  Europe  and 
America  was  interrupted,  the  price  of 
quicksilver  rose  to  such  a  height  in  the 
latter  that  it  answered  to  import  it  from 
China ;  but  since  the  peace  it  has  been 
regularly  exported  to  the  latter.  At  an 
average  of  the  14  years  ending  with  1828, 
the  imports  of  quicksilver  by  the  English 
and  Americans  into  Canton  amounted  to 
648,085  lbs  a-year,  worth  340,262  dollars. 
The  sulphuret  is  found  in  abundance  in 
California ;  the  boulders  being  mostly 
composed  of  native  cinnabar.  From  the 
attention  of  the  population  being  wholly 
turned  on  gold,  these  stones  were  ne- 
glected, and  the  quicksilver  necessary  for 


854 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[mer 


amalgamating,  was  imported  from  China. 
Besides  its  uses  in  medicine,  mercury  is 
extensively  employed  in  the  amalgama- 
tion of  the  noble  metals,  in  water-gilding, 
the  making  of  vermillion,  the  silvering 
of  looking-glasses,  the  making  of  baro- 
meters and  thermometers,  &c. 

It  has  been  long  well  known  that  quick- 
silver may  be  most  readily  extracted  from 
cinnabar,  by  heating  it  in  contact  with 
quicklime.  The  sulphur  of  the  cinnabar 
combines,  by  virtue  of  a  superior  affinity 
with  the  lime,  to  the  exclusion  of  the 
quicksilver,  to  form  sulphurets  of  lime 
and  calcium,  both  of  which  being  fixed 
Jiepars,  remain  in  the  retort  while  the 
mercury  is  volatilized  by  the  heat.  In  a 
few  places,  hammerschlag,  or  the  iron 
cinder,  driven  off  from  the  blooms  by  the 
tilting  hammer,  has  been  used  instead  of 
lime  in  the  reduction  of  this  mercurial 
ore,  whereby  sulphurous  acid  and  sulph- 
uret  of  iron  are  formed. 

The  annual  production  of  the  Bavarian 
Rhine  provinces  has  been  estimated  at 
from  400  to  550  quintals  ;  that  of  Alma- 
den,  in  the  year  1827,  was  22,000  quin- 
tals ;  and  of  Idria,  at  present,  is  not 
more  than  1500  quintals.  Those  of 
Guanca  Velica  average  1800  quintals. 

All  the  plans  hitherto  prescribed  for 
distilling  the  ore  along  with  quicklime 
are  remarkably  rude.  In  that  practised 
at  Landsberg  by  Obermoschel,  there  is  a 
great  waste  of  labor,  in  charging  the  nu- 
merous small  cucurbits  ;  there  is  a  great 
waste  of  fuel  in  the  mode  of  heating 
them  ;  a  great  waste  of  mercury  by  the 
imperfect  luting  of  the  retorts  to  the  re- 
ceivers, as  well  as  the  imperfect  conden- 
sation of  the  mercurial  vapors  ;  and  pro- 
bably a  considerable  loss  by  pilfering. 

The  modes  practised  at  Almaden  and 
Idria  are,  iu  the  greatest  degree,  barbar- 
ous; the  ores  being  heated  upon  open 
arches,  and  the  vapors  attempted  to  be 
condensed  by  inclosing  them  within  brick 
or  stone  and  mortar  walls,  which  can  never 
be  rendered  either  sufficiently  tight  or  oool. 

To  obviate  all  these  inconveniences  and 
sources  of  loss,  the  proper  chemical  ar- 
rangements suited  to  the  present  improv- 
ed state  of  the  arts  ought  to  be  adopted, 
by  which  labor,  fuel,  and  mercury,  might 
all  be  economized  to  the  utmost  extent. 
The  only  apparatus  fit  to  be  employed  is 
a  series  of  cast-iron  cylinder  retorts,  some- 
what like  those  employed  in  the  coal-gas 
works,  but  with  peculiarities  suited  to 
the  condensation  of  the  mercurial  vapors. 
Into  each  of  these  retorts,  supposed  to  be 
at  least  one  foot  square  in  area,  and  7  feet 


long,  6  or  7  cwts.  of  a  mixture  of  the 
ground  ore  with  the  quicklime,  may  be 
easily  introduced,  from  a  measured  heap, 
by  means  of  a  shovel.  The  specific  grav- 
ity of  the  cinnabar  being  more  than  six 
times  that  of  water,  a  cubic  foot  of  it  will 
weigh  more  than  3£  cwts. ;  but  supposing 
the  mixture  of  it  with  quicklime  (when 
the  ore  does  not  contain  the  calcareous 
matter  itself)  to  be  only  thrice  the  den- 
sity of  water,  then  four  cubic  feet  might 
be  put  into  each  of  the  above  retorts,  and 
still  leave  1±  cubic  feet  of  empty  space  for 
the  expansion  of  volume  which  may  take 
place  in  the  decomposition.  The  ore 
should  be  ground  to  a  moderately  fine 
powder,  by  stamps,  iron  cylinders,  or  an 
edge  wheel,  so  that,  when  mixed  with 
quicklime,  the  cinnabar  may  be  brought 
into  intimate  contact  with  its  decomposer, 
otherwise  much  of  it  will  be  dissipated 
unproductively  in  fumes,  for  it  is  extreme- 
ly volatile. 

*  A  new  process  for  the  distillation  of 
mercury  has  been  proposed  by  M.  Vio- 
lette.  It  consists  in  immersing  the  mass 
in  a  current  of  the  vapor  of  water,  heat- 
ed from  320°  to  400°  cent.  The  vapor 
acts  at  once  as  the  heating  and  the  me- 
chanical agent :  it  first  heats  the  metal  so 
as  to  produce  distillation,  and  then  drives 
before  and  draws  over  the  mercurial  va- 
por just  as  a  hot  current  of  air  promotes 
the  evaporation  of  water.  The  steam 
charged  with  the  mercurial  vapor  is  con- 
densed in  a  common  refrigerator.  The 
metai  separates  at  the  bottom  of  the  re- 
ceiver, while  the  condensed  water  floats 
above.  The  liquid  thread  which  flows  from 
the  refrigerator  consists  of  two  parts ;  an 
upper  one,  which  is  water,  and  the  under 
one,  the  mercurial  thread  :  there  is  a  con- 
tinuous current  of  both.  No  bumping 
occurs,  the  operation  going  on  as  quietly 
as  the  distillation  of  water.  The  appara- 
tus employed  consists  of  a  cast-iron  cyl- 
indrical retort  receiving  the  vessel  which 
contains  the  mercury ;  an  iron  worm, 
which,  being  heated,  the  water  circulates 
through  it,  enters  the  retort,  and  traver- 
ses it  from  one  end  to  the  other,  the  mer- 
cury being  immersed  in  it ;  it  then  escapes 
with  the  mercurial  vapor,  and  both  are 
condensed  in  the  refrigerator.  This  oper- 
ation is  simple  and  easy :  one  workman 
can  manage  an  apparatus  with  2000  lbs.  of 
amalgam.  There  is  greater  economy  of 
fuel  and  amalgam.  In  ordinary  process, 
the  latter  loss  is  2  per  cent. ;  by  this  there 
is  none,  and  there  is  no  danger  to  public 
health. 
Quicksilver  is  a  substance  of  paramount 


merJ 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


355 


value  to  science.  Its  great  density  and 
its  regular  rate  of  expansion  and  contrac- 
tion by  increase  and  diminution  of  tem- 
{>erature,  give  it  the  preference  over  all 
iquids  for  filling  barometric  and  thermo- 
metric  tubes.  In  chemistry  it  furnishes 
the  only  means  of  collecting  and  manipu- 
lating, in  the  pneumatic  trough,  such 
gaseous  bodies  as  arc  condensable  over 
water.  To  its  aid,  in  this  respect,  the 
modern  advancement  of  chemical  discov- 
ery is  pre-eminently  due. 

This  metal  alloyed  with  tin-foil  forms 
the  reflecting  surface  of  looking-glasses, 
and  by  its  ready  solution  of  gold  or  silver, 
and  subsequent  dissipation  by  a  moder- 
ate heat,  it  becomes  the  great  instrument 
of  the  arts  of  gilding  and  silvering  copper 
and  brass.  The  same  property  makes  it 
so  available  in  extracting  these  precious 
metals  from  their  ores.  The  anatomist 
applies  it  elegantly  to  distend  and  display 
the  minuter  vessels  of  the  lymphatic  sys- 
tem, and  secretory  systems,  by  injecting 
it  with  a  syringe  through  all  their  convo- 
lutions. It  is  the  basis  of  many  very 
powerful  medicines. 

Mercury  dissolves  all  the  metals  except 
iron,  forming  amalgams  with  them. 
With  arsenic  and  antimony  by  heat. 

Mercury  may  be  cleansed  by  forcing  it 
through  chamois  leather,  hazel  wood,  or 
a  cone  of  fine  paper.  Sometimes  it  is 
shaken  in  a  bottle  with  powdered  loaf- 
sugar,  and  then  passed  through  a  paper 
funnel.  If  mixed  with  other" metals,  it 
should  be  distilled. 

The  nitrate  of  mercury  is  employed  for 
the  secretage  of  rabbit  and  hare-skins, 
that  is,  for  communicating  to  the  fur  of 
these  and  other  quadrupeds  the  faculty 
of  felting,  which  they  do  not  naturally 
possess.  With  this  view  the  solution  of 
that  salt  is  applied  to  them  lightly  in  one 
direction  with  a  sponge.  A  compound 
amalgam  of  zinc  and  tin  is  probably  the 
best  "exciter  which  can  be  applied  to  the 
cushions  of  electrical  machines. 

The  only  mercurial  compounds  which 
are  extensively  used  in  the  arts,  are  facti- 
tious cinnabar  or  vermillion,  and  corro- 
sive sublimate. 

MERCURY,  BICHLORIDE  OF;  is 
made  by  subliming  a  mixture  of  equal 
parts  of  persulphate  of  mercury,  prepar- 
ed as  below  described,  and  sea-salt,  in  a 
stoneware  cucurbit.  The  sublimate  rises 
in  vapor,  and  incrusts  the  globular  glass 
capital  with  a  white  mass  of  small  pris- 
matic needles.  Its  specific  gravity  is  5-14. 
Its  taste  is  acrid,  stypto-metallic,  and  ex- 
ceedingly unpleasant.    It  is  soluble  in  20 


parts  of  water,  at  the  ordinary  tempera- 
ture, and  in  its  own  weight  of  boiling  wa- 
ter. It  dissolves  in  24  times  its  weight 
of  cold  alcohol.  It  is  a  very  deadly  pois- 
on. Raw  white  of  egg  swallowed  in  pro- 
fusion, is  the  best  antidote.  A  solution 
of  corrosive  sublimate  has  been  long  em- 
ployed for  preserving  soft  anatomical  pre- 
parations. By  this  means  the  corpse  of 
Colonel  Morland  was  embalmed  in  order 
to  be  brought  from  the  seat  of  war  to 
Paris.  His  features  remained  unaltered, 
only  his  skin  wa3  brown,  and  his  body 
was  so  hard  as  to  sound  like  a  piece  of 
wood  when  struck  with  a  hammer. 

MERCURY,  PROTOCHLORIDE  OF. 
This  compound,  so  much  used  by  medical 
practitioners,  is  commonly  prepared  by 
triturating  four  parts  of  corrosive  subli- 
mate along  with  three  parts  of  running 
quicksilver  in  a  marble  mortar,  till  the 
metallic  globules  entirely  disappear,  with 
the  production  of  a  black  powder,  which 
is  to  be  put  into  a  glass  balloon,  and  ex- 

?osed  to  a  subliming  heat  in  a  sand  bath, 
he  calomel,  which  rises  in  vapor,  and 
attaches  itself  in  a  crystalline  crust  to  the 
upper  hemisphere  of  the  balloon,  is  to  be 
detached,  reduced  to  a  fine  powder,  or 
levigated  and  elutriated.  200  lbs.  of  mer- 
cury yield  236  of  calomel  and  272  of  cor- 
rosive sublimate. 

The  following  more  economical  process 
is  that  adopted  at  the  Apothecaries'  Hall, 
London.  140  pounds  of  concentrated  sul- 
phuric acid  are  boiled  in  a  cast-iron  pot 
upon  100  pounds  of  mercury,  till  a  dry 
phosphate  is  obtained.  Of  this  salt,  124 
pounds  are  triturated  with  81  pounds  of 
mercury,  till  the  globules  disappear,  and 
till  a  protosulphate  be  formed.  This  is  to 
be  intimately  mixed  with  68  pounds  of 
sea-salt,  and  the  mixture,  being  put  into 
a  large  stone- ware  cucurbit,  i»  to  be  sub- 
mitted to  a  subliming  heat. 

From  190  to  200  pounds  of  calomel  nse 
in  a  crystalline  cake,  as  in  the  former  pro- 
cess, into  the  capital;  while  sulphate  of 
soda  remains  at  the  bottom  of  the  alem- 
bic. The  calomel  must  be  ground  to  an 
impalpable  powder,  and  elutriated.  The 
vapors,  instead  of  being  condensed  into 
a  cake  within  the  top  of  the  globe  or  in  a 
capital,  may  be  allowed  to  diffuse  them- 
selves into  a  close  vessel,  containing  wa- 
ter in  a  state  of  ebullition,  whereby  the 
calomel  is  obtained  at  once  in  the  form  of 
a  washed  impalpable  powder.  Calomel 
is  tasteless  and  insoluble  in  water.  Its 
specific  gravitv  is  7*176. 

MERCURY  (Fulminating).  §  A  fulmi- 
nating preparation  of  mercury  is  obtained 


356 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


b 


by  dissolving  100  grs.  in  11  oz.,  by  mea- 
sure, of  nitric  acid.  This  solution  is 
poured  (cold)  into  2  oz.,  by  measure,  of 
alcohol,  in  a  glass  vessel,  and  heat  is  ap- 
plied till  effervescence  is  excited,  though 
it  ordinarily  comes  on  at  common  tem- 
peratures. A  white  vapor  undulates  on 
the  surface,  and  a  powder  is  gradually 
precipitated,  which  is  immediately  to  be 
collected  on  a  filter,  well  washed,  and 
cautiously  dried.  100  grains  of  quick- 
silver attbrds  130  grs.  of  salt.  100  parts 
of  it  consists  of— 

Peroxide  of  Mercury. 76 

Fulminic  acid 24 


100 


When  well-made,  it  undergoes  no  change 
from  weather.  It  is  in  white  grains,  or 
short  needles,  when  pure ;  it  detonates 
when  struck,  or  on  being  heated  to 
370°  F.  This  powder  detonates  loudly 
by  gentle  heat  or  friction.  It  is  used  as 
the  match-powder,  or  priming,  for  the 
percussion  caps  of  detonating  locks.  Two 
grs.  and  a  half  of  it,  mixed  with  one-sixth 
of  that  weight  of  gunpowder,  form  the 
quantity  for  one  percussion  cap. 

A  soft  mastic  varnish  is  the  best  for 
making  it  adhere  to  the  cap.  These  caps 
are  sold  in  Paris  for  three  francs  per  thou- 
sand. 

MERCURY  (Sulphubets  of).  There 
are  two  sulphurets,  the  black  and  the  red, 
or  the  proto-sulphvret,  and  the  dento-sul- 
fhuret.  The  first  is  formed  by  rubbing 
vigorously  in  a  glass  or  porcelain  mortar 
three  parts  of  sulphur  and  one  of  mer- 
cury, or  by  adding  mercury  at  intervals, 
and  with  agitation,  to  its  own  weight  of 
melted  sulphur.    The  second,  which  is 


commonly  called  cinnabar,  or  veiinilion, 
is  formed  by  subliming  the  proto-sulphu- 
ret.  The  process  consists  in  grinding 
together  150  lbs.  of  sulphur  and  1080  of 
quicksilver,  and  then  heating  the  mix- 
ture in  a  cast-iron  pot,  two  and  a  half  fe^t 
in  diameter  and  one  foot  deep,  precau- 
tions being  taken  that  the  mixture  does 
not  take  fire.  The  calcined  Ethiops  is 
then  ground  to  powder,  and  introduced 
into  pots  capable  of  holding  twenty-four 
oz.  of  water  each,  to  which  are  attached 
subliming  vessels,  or  bolt  heads  of 
earthenware.  The  sublimation  usually 
takes  thirty-six  hours,  when  the  subli- 
mers  are  taken  out  of  the  furnace,  cooled 
and  broken. 

It  is  this  compound  which  is  the  most 
valuable  native  ore  for  obtaining  the  me- 
tal from.  The  beautiful  red  is  obtained 
by  sublimation  ;  when  native,  it  is  dark 
colored. 

METALS  are  a  very  numerous  class 
of  simple  bodies,  and  are  distinguished 
by  their  very  peculiar  lustre  arising  out 
of  their  opacity  and  reflective  power  in 
regard  to  Tight.  They  conduct  electricity 
and  heat ;  and  they  have  not  been  re- 
solved into  other  forms  of  matter,  so  that 
they  are  regarded  as  simple  or  elemen- 
tary substances.  When  their  compounds 
are  electrolysed  the  metals  appear  at  the 
negative  surface,  and  are  hence  consider- 
ed as  electro-positive  bodies.  They  are 
enumerated  in  the  following  table,  to- 
gether with  the  names  of  the  chemists  by 
whom  they  were  discovered,  the  date  of 
their  discovery,  their  specific  gravities, 
melting  points,  equivalent  or  atomio 
weights,  and  symbolic  abbreviations. 
For  their  individual  distinctive  charac- 
ers,  see  the  respective  metals. 


Names  of  Metals. 


Gold ©1 

Silver J) 

Iron $ 

Copper 9 

Mercury . .  8 

Lead > 

Tin 4  J 

Antimony 

Bismuth 

Zinc 

Arsenic I 

Cobalt \ 

Platinum 

Nickel 

Manganese 

Tungsten 


Authors,  and  Dates  of  their 
Discovery. 


(Known  to  the  ancients,  and 
represented  by  the  annex- 
ed planetary  symbols, 
with  which  they  were 
supposed  to  be  mysteri- 
ously connected.) 

Basil  Valentine 1490 

Agricola 1530 

Paracelsus?   1530 

Brandt 1733 

Wood 1741 

Cronstadt 1751 

Gahn 1774 

D'Elhuiart 1781 

•  Smith's  Forge. 


Specific 
Gravity. 

Melting  Points. 
rtikr. ~ 

Equivalent 
Weights. 

Abbreviations 
or  Symbols. 

'     19-25 

2016°        .... 

200 

an. 

10-47 

1873 

110 

«g- 

7-78 

2800  ?  s.  f.  * 

28 

& 

<        889 

1996 

64 

CO. 

1356 

89 

200 

Jf 

11-35 

612 

104 

7-29 

442 

58 

St 

6-70 

65 

72 

sb. 

9-80 

497 

bi. 

7-00 

778 

82 

zn. 

S       5-88 
)       8-53 

88 
80 

ar. 

2810?      .... 

CO. 

20-98 

oh.  bp.t  .... 
2810  ?      .... 

96 

pL 

8-27 

28 

nL 

6-85 

s.  f. 

28 

inn. 

17-60 

100 

to. 

f  Oxy-hydrogen  blow-pipe. 


met] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


357 


Names  of  Metal*. 

Author*,  and  Dates 
Discovery. 

of  their 

Specific 

Gravity. 

Melting 
Points. 

Equivalent 
Weights. 

Abbreviation* 
or  Symbol*. 

Midler 

...    1782 

6-11 
7-40 
9-00 
530 

{!i 

r     6-8*6* 

0-97 
"'8*60 

j :.'..:::: 
( 

Fahr. 
620?        .... 

oh.  bp 

oh.  bp 

oh.  bp 

oh.  bp 

oh.  bp 

32 
48 

217 
24 
28 

185 
54 
45 
96 

100 
48 
40 
24 
70 
44 
20 
56 
10 
8 
30 
10 
18 
82 
60 
12 
68 

te. 

18.  Molybdenu 

39.  Uranium.. m  . 

20.  Titanium 

21.  Chromium 

Hielm 

Klaproth 

Gregor 

Vauquelin 

Hatchett 

...  1782 
...  1789 
...  1791 
...  1797 

...  1802 

mo 
ur. 
ti. 
cr. 

23.  Palladium.. . .  > 
24  Rhodium.  ..  1 

25.  Iridium ) 

26.  Osmium J 

27.  Cerium 

Wollaston 

Tennant 

Hisinger 

Davy. 

Stromeyer 

Arfwedson 

Berzelius 

Wohler. 

...    1805 

...  1808 
...    1804 

...  1807 

...  1818 
....  1818 

...    1824 

....  1828 
1829 

rh. 
ir. 

OS. 

ce. 

oh.  bp 

j  oh.  bp 

\  oh.  bp 

28.  Potassium. . .  "] 

29.  Sodium j 

30.  Barium } 

31.  Strontium...   | 

82.  Calcium J 

83.  Cadmium . 

84.  Lithium 

136 
190 

po. 
so. 
ba. 

m 
ca. 

442 

cd. 

1L 

85.  Silicium ) 

86.  Zirconium. . .  J 

87.  Aluminum . .  j 

si. 
zr. 

al. 

th. 

89.  Yttrium ) 

40.  Thorium 

41.  Magnesium 

....  1829 

mg. 

1830 

43.  Pelopium 

H.  Rose 

II.  Rose 

....  1843 
....  1843 

!!''."".'..... 

pe. 
nb. 

Mosander 

Mosander 

it 
'.'".  1844 

46.  Terbium 

tr. 

Ulgreu 

Mosander 

Mosander. 

Svanberg 

....  1850 
....  1842 

M 

'.'.".'.  1845 

In. 

50.  Didymium 

dy. 

The  specific  characters  of  minerals  are 
three.  Specific  gravity,  hardness,  and 
crystaline  form,  which  last  is  either 
rhombohedral,  pyramidal,  prismatic,  or 
tossular ;  i.  e.,  hexagonal.  A  collection  of 
similar  species  are  a  genus,  of  generas  an 
order,  and  of  orders  a  class. 

There  are  seven  metals  with  proven  al- 
kaline bases ;  potassium,  sodium,  barium, 
strontium,  calcium,  magnesium,  and 
lithium. 

There  are  six  with  earthy  bases  ;  alu- 
minum, glucinum,  cerium,  yttrium,  zir- 
conium, and  thorium ;  i.  e.,  formed  by 
reducing  the  earths  to  metals  by  ab- 
stracting oxygen  from  the  earths.  When 
these  metals  are  oxidized,  the  products 
are  white  powders,  without  flavor.  The 
rest  of  the  metals  can  hardly  be  classed 
together,  as  they  have  few  properties  in 
common. 

Oxides  of  iron,  nickel,  cobalt,  and  man- 
ganese, are  irreducible  in  fire,  but  dis- 
solve in  acids. 

Oxides  of  gold,  platinum,  and  four 
others,  are  reduced  to  tho  metallic  state 


by  heat  alone,   and  they  require  great 
heat  to  oxidate  them. 

Metals,  in  general,  seek  to  return  to 
their  original  state  as  oxides,  with  two 
or  three  exceptions  of  the  harder  kinds, 
arising  apparently  from  the  excess  of  a 
silicious  or  quartz  base  over  the  alkali, 
combined  during  their  electrical  genera- 
tion. 

Despretz  gives  the  following  table  of 
the  conducting  heat  of  metals  according 
to  the  following  figures : — 

Gold,  1000 ;  platinum,  981 ;  silver,  973 ; 
copper,  898 ;  iron,  374 ;  zinc,  363 ;  tin, 
304 ;  lead,  179-6. 

Becquerel  gives  the  electrical  conduct- 
ing power  as  follows : — 

Copper,  100 ;  gold,  93-6 ;  silver,  73-6  ; 
zinc,  28-5  ;  platina,  16-4 ;  iron,  15-8  ;  tin, 
15-5  ;  lead,  8-3 ;  mercury,  3-5  ;  potassium, 
I  1-33. 

The  most  ductile  and  malleable  of  the 

metals,  in  order,  are  cadmium,  copper, 

I  gold,  iridium,  iron,  lead,  &c;  and  tin 

I  and  zinc  the  least. 

I      The  most  brittle,   are,  antimony,  ar- 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[MET 


senic,  bismuth  ;  and  tungsten,  titanium, 
and  uranium  the  least. 

The  most  facile  for  wire  poles,  in  order, 
are  gold,  silver,  platinum,  iron,  copper, 
zinc,  tin,  lead,  and  nickel. 

The  easiest  made  into  plates,  or  sheets, 
by  rollers,  in  order,  are  gold,  silver, 
copper,  tin,  platinum,  zinc,  iron,  and 
nickel. 

When  metals  require  to  be  granulated 
for  manufacturing  purposes,  they  are 
poured  into  water,  or  briskly  agitated  in 
a  box  while  congealing,  by  which  they 
fall  into  powder  instead  of  crystalizing. 
A  cullender,  or  ladle  with  holes,  is  used 
in  dropping  into  water. 

Silver  may  be  reduced  to  fine  grains 
by  first  dissolving  it  in  nitric  acid,  and 
then  immersing  a  plate  of  copper,  to 
which  the  silver  will  attach  itself;  but  it 
must  be  shaken  off  till  the  greater  part 
of  the  silver  has  settled  at  the  bottom, 
when  the  copper  and  solution  may  be 
taken  away,  and  the  precipitate  washed 
and  dried. 

Copper  may  be  obtained  in  grains  in 
like  manner,  by  immersing  a  plate  of 
iron  in  a  solution  of  the  copper  and  sul- 
phuric acid.  When  the  iron  plate  is  put 
in,  a  little  more  sulphuric  acid  should  be 
added,  and  the  copper  will  fall  to  the 
bottom,  after  which  it  should  be  washed 
with  dilute  sulphuric  acid,  and  with 
water,  and  dried. 

To  obtain  gold  in  powder,  dissolve  it 
in  muriatic  acid,  and  then  add  protosul- 
phate  of  iron.  -  The  gold  will  be  precipi- 
tated, and  then  it  should  be  washed  with 
some  muriatic  acid,  and  with  water,  and 
dried. 

Platina  may  be  had  in  fine  powder,  by 
dissolving  it  in  ammonia-muriate,  and 
heating  it  in  a  crucible  to  redness,  till  no 
more  fumes  arise.  It  then  resembles 
sponge. 

Zinc  is  reducible  to  fine  powder  when 
hot,  if  pounded  by  a  heated  iron  mortar 
in  a  heated  pestle. 

When  platina  is  alloyed  with  other 
metals,  it  becomes  soluble  with  them. 

Besides  the  alloys  enumerated  as  alloys, 
steel  500,  and  silver  1,  produce  a  fine 
cutting  metal. 

Steel,  too,  alloys  with  rhodium,  in 
razors  made  at  Sheffield  ;-  and  with  gold 
and  nickel,  also  with  platinum,   in  the 

Sroportion  1  platinum,  8  steel,  with  the 
nish  polish. 

All  the  metallic  nitrates  are  soluble. 
The  muriates  generally.  The  sulphates 
are  insoluble,  except  by  solutions  or  bary- 
tic  salts.    The  acetates  are  soluble.    The 


alkaline  earths  are  soluble  in  solutions  of 
sugar.  Tortrates  render  many  metallic 
oxides  soluble. 

Dr.  Thomson  divides  metals  into  four 
classes.  1.  Malleable  metals.  Platina, 
gold,  silver,  nickel,  mercury,  palladium, 
rhodium,  iridium,  psmium,  copper,  iron, 
tin,  lead,  and  zinc.  2.  Brittle  and  easily 
fused.  Bismuth,  antimony,  tellurium, 
and  arsenic.  3.  Brittle  and  difficult  of 
fusion.  Cobalt,  manganese,  chrome, 
molybdena,  uranium,  tungsten,  and  tit- 
anium. 4.  Refractory,  or  such  as  have 
never  yet  been  reduced.  Columbium, 
tantalium,  and  cerium. 

Metals,  like  other  fusible  bodies,  have 
each  a  fixed  temperature,  or  freezing 
point,  at  which  they  become  solid.  The 
specific  gravity  is  considerably  affected 
by  the  gradual  or  hasty  cooling,  or  tran- 
sition from  the  fluid  to  the  solid  state. 
Hammering  renders  them  harder  and 
more  elastic ;  but  this  effect  is  destroyed 
by  ignition. 

They  combine  with  hydrogen  into 
Tiydrurets ;  with  carbon,  into  carburets; 
with  sulphur,  into  sulphurets  ;  with  phos- 
phorus, into  phospTiurets  ;  with  selenium, 
into  seleniurets  ;  with  boron,  into  borurets 
(borides  ?)  ;  with  chlorine,  into  chlorides , 
with  iodine,  into  iodide*;  with  cyanogen, 
into  cyanides  ;  with  silicon,  into  silicides  ; 
and  with  fluorine,  intqjluorides. 

METALLURGY.  The  act  of  separat- 
ing metals  from  their  ores :  with  an  ore 
perfectly  pure  the  obtaining  a  pure  metal 
is  a  metallurgic  process.  It  is  not  con- 
fined however  to  this,  for  ores  are  rarely 
pure,  but  contain  earthy  ingredients, 
foreign  to,  and  injurious  in,  the  after 
treatment.  The  treatment  of  ores  is  both 
mechanical  and  chemical.  The  mechan- 
ical processes  consist  in  picking,  stamp- 
ing, and  washing.  Almost  all  ores  are 
picked  by  old  men,  women  and  children. 
After  the  larger  lumps  are  broken  by  the 
hammer,  then  use  hand  hammers  on 
these  broken  pieces,  and  then  pick  and 
sort  on  iron  trays  the  richest  lumps  of 
ore.  These  are  "at  once  fit  for  smelting. 
The  very  coarsest  are  thrown  aside  as 
useless,  and  the  intermediate  lumps, 
which  contain  ore  and  stone,  so  inter- 
mixed as  not  to  be  separated  by  hand, 
are  passed  on  to  undergo  the  process  of 
stamping. 

Before  describing  the  refined  methods 
of  washing  the  more  valuable  ores  of 
copper,  silver,  lead,  &c,  it  is  proper  to 
point  out  the  means  of  reducing  them  into 
a  powder  of  greater  or  less  fineness,  by 
stamping,  so  called  from  the  name  staMp* 


met] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


359 


of  the  pestles  employed  for  chat  pur- 
pose. Its  usefulness  is  not  restricted  to 
preparing  the  ores ;  for  it  is  employed  in 
almost  every  smelting  house  for  pound- 
ing clays,  charcoal,  scoriae,  &c.  A 
stamping  mill  or  pounding  machine  con- 
sists of  several  movable  pillars  of  wood, 
placed  vertically,  and  supported  in  this 
position  between  frames  of  carpentry. 
These  pieces  are  each  armed  at  their 
under  end  with  a  mass  of  iron.  An  arbor 
or  axle,  moved  by  water,  and  turning 
horizontally,  tosses  up  these  wooden 
pestles,  by  means  of  wipers  or  cams, 
which  lay  hold  of  the  shoulders  of  the 
pestles.  These  are  raised  in  succession, 
and  fall  into  an  oblong  trough  below, 
scooped  out  in  the  ground,  having  its 
bottom  covered  either  with  plates  of  iron, 
or  hard  stones.  In  this  trough,  beneath 
these  pestles,  the  ore  to  be  stamped  is 
allowed  to  fall  from  a  hopper  above, 
which  is  kept  constantly  full. 

The  trough  is  closed  in  at  the  sides  by 
two  partitions,  and  includes  three  or  four 
pestles ;  which  the  French  miners  call  a 
battery.  They  are  so  disposed  that  their 
ascent  and  descent  take  place  at  equal  in- 
tervals of  time. 

Usually  a  stamping  machine  is  com- 
posed of  several  batteries  (two,  three,  or 
tour),  and  the  arrangement  of  the  wipers 
on  the  arbor  of  the  hydraulic  wheel  is 
such  that  there  is  constantly  a  like  num- 
ber of  pestles  lifted  at  a  time — a  circum- 
stance important  for  maintaining  the 
uniform  going  of  the  machine. 

The  matter*  that  are  not  to  be  exposed 
to  subsequent  washing  are  stamped:  dry, 
that  is,  without  leading  water  into  the 
trough ;  and  the  same  thing  is  sometimes 
done  with  the  rich  ores,  whose  lighter 
parts  might  otherwise  be  lost. 

Most  usually,  especially  for  ores  of 
Jead,  silver,  copper,  &c,  the  trough  of 
the  stamper  is  placed  in  the  middle  of  a 
current  of  water,  of  greater  or  less  force ; 
which,  sweeping  off  the  pounded  sub- 
stances, deposits  them  at  a  greater  or  less 
distance  onwards,  in  the  order  of  the  size 
and  richness  of  the  grain ;  constituting 
a  first  washing,  as  they  escape  from  be- 
neath the  pestles. 

After  the  ore  is  stamped  it  undergoes 
the  next  process,  that  of  washing.  This 
is  a  tedious  and  costly  operation,  and  has 
for  its  object  the  separation  of  the  earthy 
from  the  metallic  part  of  the  ore,  and 
depends  upon  the  fact  that  the  latter  is 
heavier  than  the  former.  Before  being 
washed  the  ore  is  generally  riddled  or 
sifted  by  hand  or  machine. 


Sometimes,  as  at  Poullaouen,  the  sieves 
are  conical,  and  held  by  means  of  two 
handles  by  a  workman ;  and  instead  of 
receiving  a  single  movement,  as  in  the 
preceding  method,  the  sifter  himself 
gives  them  a  variety  of  dexterous  move- 
ments in  succession.  His  object  is  to 
separate  the  poor  portions  of  the  ore  from 
the  richer;  in  order  to  subject  the  former 
to  the  stamp  mill. 

Among  the  siftings  and  washings 
which  ores  are  made  to  undergo,  the 
most  useful  and  ingenious  are  those 
practised  by  iron,  gratings,  called  on  the 
Continent  grilles  anglaises,  and  the  step- 
washings  of  Hungary,  laveries  a  grandins. 
These  methods  of  freeing  the  ores  from 
the  pulverulent  earthy  matters,  consist 
in  placing  them,  at  their  out-put  from  the 
mine,  upon  gratings,  and  bringing  over 
them  a  stream  of  water,  which  merelv 
takes  down  through  the  bars  the  small 
fragments,  but  carries  off  the  pulverulent 
portions.  The  latter  are  received  in  cis- 
terns, where  they  are  allowed  tore9tlong 
enough  to  settle  to  the  bottom.  The 
washing  by  3teps  is  an  extension  of  the 
preceding  plan.  To  form  an  idea,  let  us 
imagine  a  series  of  grates  placed  succes- 
sively at  different  levels,  so  that  the 
water,  arriving  on  the  highest,  where  the 
ore  for  washing  lies,  carries  off  a  portion 
of  it,  through  this  first  grate  upon  a 
second  closer  in  its  bars,  thence  to  a  third, 
&c,  and  finally  into  labyrinths  or  cis- 
terns of  deposition. 

In  certain  mines  of  the  Hartz,  tables 
called  h  balais,  or  sweeping  tables,  are 
employed.  The  whole  of  the  process 
consists  in  letting  flow,  over  the  sloping 
table,  in  successive  currents,  water 
charged  with  the  ore,  which  is  deposited 
at  a  less  or  greater  distance,  as  also  pure 
water  for  the  purpose  of  washing  the  de- 
posited ore,  afterwards  carried  off  by 
means  of  this  sweeping  Operation. 

At  the  upper  end  of  these  sweep-tables, 
the  matters  for  washing  are  agitated  in  a 
chest,  by  a  small  wheel  with  vanes,  or 
flap-boards.  The  conduit  of  the  muddy 
waters  opens  above  a  little  table  or  shelf; 
the  conduit  of  pure  water,  which  adjoins 
the  preceding,  opens  below  it.  At  the 
lower  part  of  each  of  these  tables,  there 
is  a  transverse  slit,  covered  by  a  small 
door  with  hinges,  opening  outwardly,  by 
falling  back  towards  the  foot  of  the  table. 
The  water  spreading  over  the  table,  may 
at  pleasure  be  let  into  this  slit,  by  raising 
a  bit  of  leather  which  is  nailed  to  the 
table,  so  as  to  cover  the  small  door  when 
it  is  in  the  shut  position ;  but  when  this 


360 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


\> 


is  opened,  the  piece  of  leather  then  hangs 
down  into  it.  Otherwise  the  water  may 
he  allowed  to  pass  freely  above  the  leather, 
when  the  door  is  shut.  The  same  thing 
may  be  done  with  a  similar  opening 
placed  above  the  conduit.  By  means  of 
these  two  slits,  two  distinct  qualities  of 
schlich  may  be  obtained,  which  are  de- 
posited into  two  distinct  conduits  or 
canals.  The  refuse  of  the  operation  is 
turned  into  another  conduit,  and  after- 
wards into  ulterior  reservoirs,  whence  it 
is  lifted  out  to  undergo  a  new  wash- 
ing. 

In  the  percussion  tables,  the  water  for 
washing  the  ores  is  sometimes  spread  in 
slender  streamlets,  sometimes  in  a  full 
body,  so  as  to  let  two  cubic  feet  escape 
per  minute.  The  number  of  shocks  com- 
municated per  minute,  varies  from  15  to 
36  ;  and  the  table  may  be  pushed  out  of 
its  settled  position  at  one  time,  three  quar- 
ters of  an  inch,  at  another  nearly  8  in- 
ches. The  coarse  ore-sand  requires  in 
general  less  water,  and  less  slope  of  table, 
than  the  fine  and  pasty  sand. 

The  mechanical  operations  which  ores 
undergo,  take  place  commonly  at  their 
out-put  from  the  mine,  and  without  any 
intermediate  operation.  Sometimes,  how- 
ever the  hardness  of  certain  gangues 
(vein-stones),  and  of  certain  iron  ores,  is 
diminished  by  subjecting  them  to  cal- 
cination previously  to  the  breaking  and 
stamping  processes. 

When  it  is  intended  to  wash  certain 
ores,  an  operation  founded  on  the  differ- 
ence of  their  specific  gravities,  it  may 
happen  that  by  slightly  changing  the 
chemical  state  of  the  substances  that  com- 
pose the  ore,  the  earthy  parts  may  become 
more  easily  separable,  as  also  the  other 
foreign  matters.  With  this  view,  the 
ores  of  tin  are  subjected  to  a  roasting, 
which  by  separating  the  arsenic,  and 
oxidizing  the  copper  which  are  inter- 
mixed, furnishes  the  means  of  obtaining, 
by  the  subsequent  washing,  an  oxide  of 
tin  much  purer  than  could  be  otherwise 
procured.  In  general,  however,  these 
are  rare  cases ;  so  that  the  washing  al- 
most always  immediately  succeed*  the 
picking  and  stamping;  and  the  roast- 
ing comes  next,  when  it  needs  to  be  em- 
ployed. 

The  mechanical  processes  tenunate 
here:  the  further  treatment  of  them  is 
chemical :  this  consists  chiefly  in  calcin- 
ation or  roasting. 

The  operation  of  roasting  is  in  general 
executed  by  various  processes,  relatively 
to  the  nature  of  the  ores,  the  quality  of 


the  fuel,  and  to  the  object  in  view.  The 
greatest  economy  have  to  be  studied  in 
the  fuel,  as  well  as  the  labor ;  two  most 
important  circumstances,  on  account  o* 
the  great  masses  operated  upon. 

Three  principal  methods  may  be  dis 
tinguished ;  1,  the  roasting  in  a  heap  in 
the  open  air,  the  most  simple  of  the 
whole ;  2,  the  roasting  executed  between 
little  walls,  and  which  may  be  called  case- 
roasting  ;  and  3,  roasting  in  furnaces. 

We  may  remark,  as  to  the  description 
about  to  be  given  of  these  different  pro- 
cesses, that  in  the  first  two,  the  fuel  is 
always  in  immediate  contact  with  the  ore 
to  be  roasted,  whilst  in  furnaces,  this 
contact  may  or  may  not  take  place. 

The  roasting  in  the  open  air,  and  in 
heaps  more  or  less  considerable,  is  prac- 
tised upon  iron  ores,  and  such  as  are  py- 
ritous  or  bituminous.  The  operation 
consists  in  general  in  spreading  over  a 
plane  area,  often  bottomed  with  beaten 
clay,  billets  of  wood  arranged  like  the 
bars  of  a  gridiron,  and  sometimes  laid 
crosswise  over  one  another,  so  as  to  form 
a  uniform  flat  bed.  Sometimes  wood 
charcoal  is  scattered  in,  so  as  to  fill  up 
the  interstices,  and  to  prevent  the  ore 
from  falling  between  the  other  pieces  of 
the  fuel.  Coal  is  also  employed  in  mo- 
derately small  lumps ;  and  even  occasion- 
ally turf.  The  ore,  either  simply  broken 
into  pieces,  or  even  sometimes  under  the 
form  of  schlich,  is  piled  up  over  the  fuel : 
most  usually  alternate  beds  of  fuel  and 
ore  are  formed. 

The  fire,  kindled  in  general  at  the  lower 
part,  but  sometimes,  however,  at  the  mid- 
dle chimney,  spreads  from  spot  to  spot, 
Eutting  the  operation  in  train.    The  com- 
ustion  must  be  so  conducted  as  to  be 
slow  and  suffocated,  to  prolong  the  ustu- 
lation,  and  let  the  whole  mass  be  equally 
j  penetrated  with  heat.    The  means  em- 
|  ployed  to  direct  the  fire,  are  to  cover  out- 
i  wardly  with  earth  the  portions  where  too 
much  activity  is  displayed,  and  to  pierce 
with  holes  or  to  give  air  to  those  where  it 
is  imperfectly  developed.    Rains,  winds, 
variable  seasons,  and  especially  good  pri- 
mary arrangements  of  a  calcination,  have 
much  influence  on  this  process,  which  re- 
j  quires,  besides,  an  almost  incessant  in- 
1  spection  at  constant  intervals. 

The  manner  of  case  roasting  has  been 
noticed  under  the  head  of  the  articles 
alum  and  iron,  to  which  the  reader  is  re- 
ferred. 

Iron  ore  is  thus  roasted  in  the  open  air 
to  free  it  from  carbonic  acid  and  water. 
Sulphuret  of  copper  and  iron  (pyrites) 


met] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


361 


are  so  treated  to  get  rid  of  some  of  the 
sulphur  :  sulphates  are,  however,  apt  to 
fuse  and  run  together  into  masses  which 
are  troublesome  afterwards.  Open  air 
roasting  is  rarely  as  effective  as  that  in 
the  reverberating  furnace.  It  is  that  best 
suited  for  powdery  ores,  and  the  flame 
has  a  powerfully  oxidizing  effect.  On 
this,  Dr.  Ure  remarks  : — 

But  in  every  case  where  it  is  desired  to 
have  a  very  perfect  roasting,  as  for  blende, 
from  which  zinc  is  to  be  extracted,  for 
sulphuret  of  antimony,  &c,  or  even  for 
ores  reduced  to  a  very  fine  powder,  and 
destined  for  amalgamation,  it  is  proper  to 
perform  the  operation  in  a  reverberatory 
furnace.  When  very  fusible  sulphurous 
ores  are  treated,  the  workman  charged 
with  the  calcination  must  employ  much 
care  and  experience,  chiefly  in  the  man- 
agement of  the  fire.  It  will  sometimes, 
indeed,  happen,  that  the  ore  partially 
fuses;  when  it  becomes  necessary  to 
withdraw  the  materials  from  the  furnace, 
to  let  them  cool  and  grind  them  anew,  in 
order  to  recommence  the  operation.  The 
construction  of  these  furnaces  demands 
no  other  attention  than  to  give  to  the  sole 
or  laboratory  the  suitable  size,  and  so  to 
proportion  to  this  the  grate  and  the  chim- 
ney that  the  heating  may  be  effected  with 
the  greatest  economy. 

The  reverberatory  furnace  is  always 
employed  to  roast  the  ores  of  precious 
metals,  and  especially  those  for  amalga- 
mation ;  as  the  latter  often  contain  arse- 
nic, antimony,  and  other  volatile  sub- 
stances, they  must  be  disposed  of  in  a 
peculiar  manner. 

The  sole,  usually  very  spacious,  is  di- 
vided into  two  parts,  of  which  the  one 
farthest  off  from  the  furnace  is  a  little 
higher  than  the  other.  Above  the  vault 
there  is  a  space  or  chamber  in  which  the 
ore  is  deposited,  and  which  communicates 
with  the  laboratory  by  a  vertical  passage ; 
which  serves  to  allow  the  ore  to  be  push- 
ed down,  when  it  is  dried  and  a  little 
neated.  The  flame  and  the  smoke  which 
escape  from  the  sole  or  laboratory  pass 
into  condensing  chambers,  before  enter- 
ing into  the  chimney  of  draught,  so  as  to 
deposite  in  them  the  oxide  of  arsenic  and 
other  substances.  When  the  ore  on  the 
part  of  the  sole  farthest  from  the  grate 
has  suffered  so  much  heat  as  to  begin  to 
be  roasted,  has  become  less  fusible,  and 
when  the  roasting  of  that  in  the  nearer 
part  of  the  sole  is  completed,  the  former 
is  raked  towards  the  fire-bridge,  and  its 
ustulation  is  finished  by  stirring  it  over 
frequently  with  a  paddle,  skilfully  work- 
16 


ed,  through  one  of  the  doors  left  in  the 
side  for  this  purpose.  The  operation  is 
considered  to  be  finished  when  the  vapors 
and  the  smell  have  almost  wholly  ceased  ; 
its  duration  depending  obviously  on  the 
nature  of  the  ores. 

The  last  department  of  metallurgy 
which  need  be  noticed,  is  the  assaying. 
Under  the  head  of  Assay  a  general  out- 
line of  the  mode  of  producing  is  given  : 
three  modes  of  assaying  may  be  followed. 
1st.  The  mechanical  assay.  2nd.  Assay 
by  the  dry  way.  3rd.  Assay  by  the  moist 
way. 

1.  Of  Mechanical  assays. — These  kind* 
of  assays  consist  in  the  separation  of  the 
substances  mechanically  mixed  in  the 
ores,  and  are  performed  by  a  hand-wash- 
ing, in  a  small  trough  of  an  oblong  shape. 
After  pulverizing  with  more  or  less  pains 
the  matters  to  be  assayed  by  this  process, 
a  determinate  weight  of  them  is  put  into 
this  wooden  bowl  with  a  little  water ;  and 
by  means  of  certain  movements  and  some 
precautions,  to  be  learned  only  by  prac- 
tise, the  lightest  substances  may  be  pretty 
exactly  separated,  namely,  the  earthy 
gangues  from  the  denser  matter  or  me- 
tallic particles,  without  loosing  any  sensi- 
ble portion  of  them.  Thus  a  schiich  of 
greater  or  less  purity  will  be  obtained, 
which  may  afford  the  means  of  judging 
by  its  quality  of  the  richness  of  the  as- 
sayed ores,  and  which  may  thereafter  be 
subjected  to  assays  of  another  kind, 
whereby  the  whole  metal  may  be  insula- 
ted. 

Washing,  as  an  assay,  is  practised  on 
auriferous  sands ;  on  all  ores  from  the 
stamps,  and  even  on  schlichs  already 
washed  upon  the  great  scale,  to  appreci- 
ate more  nicely  the  degree  of  purity  they 
have  acquired.  The  ores  of  tin  in  which 
the  oxide  is  often  disseminated  in  much 
earthy  gangue,  are  well  adapted  to  this 
species  of  assay,  because  the  tin  oxide  is 
very  dense.  The  mechanical  assay  may 
also  be  employed  in  reference  to  the  ores 
whose  metallic  portion  presents  a  uniform 
composition,  provided  it  also  possesses 
considerable  specific  gravity.  Thus  the 
ores  of  sulphuret  of  lead  (galena)  being 
susceptible  of  becoming  almost  pure  sul- 
phurets  (within  1  or  2 per  cent.)  by  mere 
washing  skilfully  conducted,  the  richness 
of  that  ore  in  pure  galena,  and  conse- 
quently in  lead,  may  be  at  once  conclud- 
ed ;  since  120  of  galena  contain  104  of 
lead,  and  16  of  sulphur.  The  sulphuret 
of  antimony  mingled  with  its  gangue 
may  be  subjected  to  the  same  mode  of 
assay,  and  the  result  will  be  still  more 


362 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[MET 


direct,  since  the  crude  antimony  is  j 
brought  into  the  market  after  being  treed  ; 
from  its  gangue  by  a  simple  fusion. 

Of  Assays  by  the  dry  way. — The  assay 
by  the  dry  way  has  for  its  object,  to  show 
the  nature  and  proportion  of  the  metals 
contained  in  a  mineral  substance.  To 
make  a  good  assay,  however,  it  is  indis- 
pensably necessary  to  know  what  is  the 
metal  associated  with  it,  and  even  within 
certain  limits,  the  quantity  of  the  foreign 
bodies.  Only  one  metal  is  commonly 
looked  after  ;  unless  in  the  case  of  cer- 
tain argentiferous  ores.  The  mineralo- 
gical  examination  of  the  substances  under 
treatment,  is  most  commonly  sufficient  to 
afford  data  in  these  respects  ;  but  the 
assays  may  always  be  varied  witn  different 
views,  before  stopping  at  a  definite  re- 
sult; and  in  every  instance,  only  such 
assays  can  be  confided  in,  as  have  been 
verified  by  a  double  operation. 

This  mode  of  assaying  requires  only  a 
little  experience,  with  a  simple  appara- 
tus ;  and  is  of  such  a  nature  as  to  be  prac- 
tised currently  in  the  smelting  works. 
The  air  furnace  and  crucibles  employed 
are  described  in  all  good  elementary  che- 
mical books.  These  assays  are  usually 
performed  with  the  addition  of  a  flux  to 
the  ore^or  some  agent  for  separating  the 
earthy  from  the  metallic  substances  ;  and 
they  possess  a  peculiar  advantage  relative 
to  the  smelting  operations,  because  they 
offer  many  analogies  between  results  on 
the  great  scale  and  experiments  on  the 
small.  This  may  even  enable  us  often 
to  deduce,  from  the  manner  in  which  the 
assay  has  succeeded  with  a  certain  flux, 
and  at  a  certain  degree  of  heat,  valuable 
indications  as  to  the  treatment  of  the  ore 
in  the  great  way. 

For  assays  in  the  dry  way,  both  of 
stony  and  metallic  minerals,  the  process  of 
Dr.  Abich  deserves  recommendation.  It 
consists  in  mixing  the  pulverized  mineral 
with  4  or  6  times  its  weight  of  carbonate 
of  baryta  in  powder,  fusing  the  mixture 
at  a  white  heat,  and  then  dissolving  it, 
after  it  cools,  in  dilute  muriatic  acid.  The 
most  refractory  minerals,  even  corundum, 
cyanate,  staurolite,  zircon,  and  feldspar, 
yield  readily  to  this  treatment.  This  pro- 
cess may  be  employed  with  advantage 
upon  poor  refractory  ores.  The  platinum 
crucible,  into  whicla  the  mixed  materials 
are  put  for  fusion,  should  be  placed  in  a 
Hessian  crucible,  and  surrounded  with 
good  coke. 

It  never,  however,  furnishes  exact  re- 
sults. To  obtain  them  it  is  necessary  to 
resort  to  assays  by  the  moist  way,  which 


are  regular  chemical  operations,  requiring 
much  skill  and  experience  in  chemical 
analyses.  The  process  generally  consists 
of  solution  of  the  ore  in  acid,  determining 
the  insoluble  earthy  matters  (gangue), 
then  taking  the  clear  solution,  and  sepa- 
rating the  several  parts  of  the  ore  out  of 
the  solution  by  the  proper  re-agents.  The 
limits  of  this  work  do  not  admit  of  enter- 
ing into  the  processes  necessary  for  indi 
vidual  metals;  they  are  found  in  the 
standard  works  on  assaying. 

Since  the  publication  of  the  improved 
method  of  making  cyanide  of  potassium, 
by  Liebig,  great  advance  has  been  made 
in  assaying  by  the  humid  way,  as  this 
salt  possesses  the  property  of  separating 
many  metals  in  mixea  solutions. 

This  salt  is  the  best  re-agent  for  de- 
tecting nickel  in  cobalt.  The  solution  of 
the  two  metals  being  acidulated,  the 
cyanide  is  to  be  added  until  the  precipi- 
tate that  first  falls  is  redissolved.  Dilute 
sulphuric  acid  is  then  added,  and  the 
mixture  being  warmed  and  left  in  repose, 
a  precipitate  does  not  fail  to  appear 
sooner  or  later,  which  is  a  compound  of 
nickel.  Cyanide  of  potassium  serves 
well  to  separate  lead,  bismuth,  cadmium, 
and  copper,  four  metals  often  associated 
in  ores.  On  adding  the  cyanide  in  excess 
to  the  solution  of  these  metals  in  nitric 
acid,  lead  and  bismuth  fall  as  carbonates, 
and  may  be  parted  from  each  other  by 
sulphuric  acid.  Sulphuretted  hydrogen 
is  passed  in  excess  through  the  residuary 
solution,  and  the  mixture  being  heated, 
a  small  quantity  of  cyanide  is  added ;  a 
yellow  precipitate  indicates  cadmium; 
and  a  black  precipitate  falls  on  the  addi- 
tion of  hydrochloric  acid,  if  copper  be 
present. 

If  into  a  crucible  (containing  the  cyan- 
ide fused  by  heat),  a  little  of  any  metallic 
oxide  be  thrown  at  intervals,  it  will  be  al- 
most immediately  reduced  to  the  regu- 
line  state.  When  the  fluid  mass  is  after- 
ward decanted,  the  metal  will  be  found 
mixed  with  the  white  saline  matter,  from 
which  it  may  be  separated  by  water. 

Even  metallic  sulphurets  are  reduced 
to  the  state  of  pure  metals  by  being  pro- 
jected in  a  state  of  fine  powder  into  the 
fused  cyanide.  When  an  iron  ore  is  thus 
introduced,  along  with  carbonate  of  pot- 
ash or  soda,  and  the  mixture  is  heated  to 
fusion,  which  requires  a  strong  red  heat, 
the  alumina  and  silica  of  the  ore  fuse  into 
a  slag ;  from  which,  on  cooling,  the  me- 
tallic iron  may  be  separated  by  the  action 
of  water,  and"  then  weighed.  If  manga- 
nese exist  in  the  ore,  it  remains  in  the 


met] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


363 


state  of  protoxide ;  to  be  determined  by  i 
a  separate  process.  When  oxide  of  cop- 
per is  sprinkled  on  the  surface  of  the 
fused  cyanide,  it  is  immediately  reduced, 
with  the  disengagement  of  heat  and  light. 
The  mixture  being  poured  out  of  the  cru- 
cible and  concreted,  is  to  be  ground  and 
washed,  when  a  pure  regulus  of  copper 
will  be  obtained. 

The  process  of  reduction  is  peculiarly 
interesting  with  the  oxide  of  antimony 
and  tin  ;  being  accomplished  at  a  low  red 
heat,  hardly  visible  in  daylight.  (  Even 
the  sulphurets  of  these  metals  are  imme- 
diately stripped  of  their  sulphur,  with  the 
formation  of  sulpho-cyanide  of  potassium. 

Cyanide  of  potassium,  mixed  with  car- 
bonate of  soda,  is  an  excellent  re-agent 
in  blow-pipe  operations  for  distinguish- 
ing metals.  The  reductions  take  place 
with  the  utmost  facility,  and  the  fused 
mixture  does  not  sink  into  the  charcoal, 
as  carbonate  of  soda  alone  is  apt  to  do  in 
such  cases.  Hence  the  grains  or  bends 
of  metal  are  more  visible,  and  can  be  bet- 
ter examined. 

When  the  cyanide  is  heated  along  with 
the  nitrates  and  chlorates  (of  potash),  it 
causes  a  rapid  decomposition,  accompa- 
nied with  light  and  explosions. 

Arsenic  may  be  readily  detected  in  the 
commercial  sulphuret  of  antimony,  by 
fusing  it  with  three-fourths  of  its  weight 
of  the  cvanide  in  a  porcelain  crucible 
over  a  spirit-lamp,  when  a  regulus  of  an- 
timony is  obtained.  The  metal  may  then 
be  easily  tested  for  arsenic,  since  none  of 
this  volatile  substance  can  have  been  lost, 
owing  to  the  low  temperature  employed. 

When  arsenious  acid,  or  orpiment,  or 
any  of  the  arseniates,  are  mixed  with  six 
times  their  weight  of  the  mixture  of  cyan- 
ide and  carbonate  of  soda  in  a  tube  with 
a  bulb  at  one  end,  and  heat  applied  with 
a  spirit-lamp  to  the  glass,  very  beautiful 
rings  of  metallic  mirror  are  formed  by 
the  reduced  arsenic.  The  arseniates  of 
lead  and  peroxide  of  iron,  however,  do 
not  answer  the  test. 

When  sulphates  of  lead  and  barytes, 
along  with  silicia,  are  mixed  with  four  or 
five  times  their  weight  of  the  above  mixed 
cyanide  and  carbonate,  and  fused,  the 
sulphate  of  lead  is  reduced  to  the  metal- 
lic state,  the  sulphate  of  barytes  becomes 
a  carbonate,  and  the  silica  gets  combined 
with  the  alkali  into  a  soluble  glass. 

METEORITES  are  stones  of  a  peculiar 
aspect  and  composition,  which  have  fallen 
from  the  air. 

METER.  An  instrument  for  measur- 
ing gas.    When  gas  commenced  to  be 


used  extensively,  it  was  found  necessary 
to  have  some  check  upon  the  gas-works 
as  well  as  the  public,  as  a  means  of  calcu- 
lating between  the  works  and  large  con- 
sumers, and  indicating  accurately  the 
amount  consumed.  This  has  been,  to  a 
great  extent,  accomplished  by  the  gas- 
clock  or  gas-meter.  The  principle  in  the 
construction  is  simple.  When  a  number 
of  vessels  of  a  certain  capacity,  say  1  cu- 
bic foot,  are  so  arranged  that  (without 
loss  of  gas  in  the  interval)  one  after  the 
other  shall  be  filled  by  the  gas  in  passing, 
and  for  this  purpose  are  inverted  in  wa- 
ter, into  which  the  gas  enters,  just  as  is 
the  case  on  a  large  scale  with  the  gasom- 
eter ;  it  follows,  that  just  as  many  cubic 
feet  of  gas  will  have  passed,  as  there  are 
air-vessels  that  have  filled.  If  these  ves- 
sels be  attached  to  a  common  axis,  upon 
which  they  revolve  as  they  fill  and  rise, 
every  revolution  will  correspond  with  4 
cubic  feet  of  gas  that  have  passed  through. 
In  the  actual  gas-meter,  instead  of  sep- 
arate vessels,  compartments  of  a  drum  of 
equal  and  known  capacity  are  used.  The 
drum  revolves  in  a  case  more  than  half 
filled  with  water  (dilute  alcohol  in  winter), 
and  is  divided  by  4  crooked  partitions  into 
as  many  chambers.  The  contents  of  each 
chamber  are  closed  at  the  front  and  back 
by  the  straight  sides  of  the  drum,  above, 
by  the  crooked  partition,  and  below  by 
the  water.  The  tube  for  the  admission 
of  the  gas  enters  at  the  back,  and  delivers 
into  the  uppermost  box ;  as  this  fills  it  be- 
comes lighter,  and  rising,  revolves  on  its 
axis  until  it  gets  above  the  level  of  the 
water,  when  it  parts  with  the  gas  through 
a  narrow  slit  into  the  space  aoove,  when 
the  gas  is  carried  on  into  the  consuming 
pipe.  The  moment  one  chamber  is  emp- 
tied, another  is  filled  with  water  and 
placed  above  the  pipe,  which  enters  from 
the  back  ;  it  becomes  filled  and  acts  simi- 
larly to  the  first,  and  so  on,  with  the  four. 
To  the  axis  of  the  drum  is  attached  a  • 

toothed  wheel,  which  turns  a  hand  by 
means  of  works  upon  a  clock  plate,  which 
has  generally  3  dials,  indicating  1, 10,  and 
100  revolutions,  and  thus  the  quantity  of 
gas  which  has  passed  is  ascertained  in 
cubic  feet. 

In  practice,  the  construction  of  the  wet 
metre  admits  of  fraud  being  practised 
with  it.  If,  for  instance,  the  water  level 
be  lowered,  more  gas  will  pass  through 
than  will  be  registered ;  if  the  meter  be 
tilted  forward  and  some  of  the  fluid  drawn 
out,  gas  will  pass  through  without  being 
registered  at  all. 

These  objections  have  given  rise  to  the 


364 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


tise  of  dry  meters,  in  which  any  fluid  in 
the  box  is  dispensed  with.  In  dry  me- 
ters, the  gas  is  measured  by  the  number 
of  times  that  a  certain  bulk  will  fill  a 
chamber  capable  of  undergoing  contrac- 
tion and  expansion  by  the  passage  of  the 
gas.  These  alternate  contractions  and 
expansions  of  the  chamber,  set  valves  in 
motion,  which,  aided  by  light  arms  and 
wheels,  turn  the  hand  of  a  dial,  as  in 
the  wet  meter.  The  largest  meter  yet 
constructed  is  one  by  Mr.  Defries,  on  the 
dry  meter  plan,  for  the  registering  the 
gas  used  in  Covent  Garden  Theatre,  Lon- 
don. It  is  said  to  be  very  accurate  in  its 
measurements.  It  contains  two  cham- 
bers :  the  upper  one  holds  the  machin- 
ery;  the  lower  is  divided  into  6  compart- 
ments by  three  movable  diaphragms, 
and  3  fixed  partitions.  The  gas  enters  at 
the  inlet  pipe,  whence  it  passes  through 
the  bottom  of  the  meter,  and  fills  each 
compartment  in  succession,  a  continuous 
supply  is  kept  up  by  the  action  on  the 
movable  diaphragms,  which  acts  on  the 
indicating  machinery  by  means  of  a  very 
simple  and  ingenious  contrivance  that 
registers  the  consumption  of  gas  with 
unerring  accuracy  on  a  plate  of  6  dials 
and  indexes,  from  units  to  millions.  This 
meter  is  capable  of  measuring  6000  cubic 
feet  per  hour,  and  is  to  measure  the  sup- 
ply of  1500  burners.  It  weighs  2  tons,  is 
16  feet  in  circumference,  and  8  in  height. 
The  shape  is  a  hexagon,  with  gothic  de- 
vices. 

The  wet  gas-meter  can  be  made  to  in- 
dicate favorably  for  the  gas_  companies, 
and  it  is  more  frequently  in  error  on 
that  side,  than  favoring  the  consumer; 
the  dry  meter  does  not  appear  to  be 
based  on  true  philosophical  principles, 
and  will,  in  all  likelihood,  not  hold  its 
ground.  A  correct  meter  is  still  a  de- 
sideratum. 

METHYLENE,  a  peculiar  liquid  com- 
pound of  carbon  and  hydrogen,  extracted 
From  pyroxylic  spirit,  which  is  reckoned 
to  be  a  bi-hydrate  of  methylene. 

MICA  is  a  finely  foliated  mineral,  of  a 
pearly  metallic  lustre.  It  is  harder  than 
gypsum,  but  not  so  hard  as  calc-spar ; 
flexible  and  elastic ;  spec.  grav.  2*65.  It 
is  an  ingredient  of  granite  and  gneiss  ;  in 
this  country  commonly  called  isinglass  ; 
in  Europe  it  is  occasionally  called  Mus- 
covy-talc. The  largest  sheets  are  found 
in  Siberia,  Canada,  and  the  New  England 
States.  Its  primitive  form  is  an  oblique 
rhombic  prism ;  ordinarily  it  is  a  six-sid- 
ed table ;  its  cleavage  is  perfect.  There 
is  great  diversity  in  the  composition  of 


[mic 


mica  coming  from  different  localities: 
generally  it  is  a  silicate  of  alumina  united 
with  silicates  of  iron  and  potash.  Some- 
times manganese  replaces  the  alumina,  as 
in  the  mica  of  Mt.  St.  Gothard ;  some- 
times magnesia  replaces  the  potash,  and 
titanium  the  iron.  That  from  Siberia 
yielded  to  Klaproth,  in  100  parts  : 

Alumina 34*25 

Silica 48-00 

Oxide  of  iron 4-50 

Oxide  of  Manganese trace 

Magnesia 0-50 

Potash 8-75 

The  mica  of  Fahlun,  analyzed  by  Rose, 
afforded,  silica,  46*22 ;  alumina,  34*52 ; 
peroxide  (?)  of  iron,  6-04 ;  potash,  8,22  ; 
magnesia,  with  oxide  of  manganese, 
2-11 ;  fluoric  acid,  1-09  ;  water,  0-98. 

Very  beautiful  specimens  of  mica 
abound  in  the  United  States.  At  Ac- 
worth,  N.  H.,  they  lie  imbedded  in  fel- 
spar ;  at  Monroe,  N.  Y .,  a  large  vein  of 
a  green-colored  variety  exists.  The  crys- 
tals at  Goshen,  Mass.",  are  rose-red,  and 
rhomboidal,  and  that  in  Brunswick,  Me., 
is  in  emerald  green  scales.  Lepidolite  is 
a  variety  of  mica  containing  fithia  and 
fluoric  acid ;  it  occurs  at  Paris,  Maine. 
Brown  and  gray  mica  are  used  in  lan- 
terns, in  stove-doors,  and  in  the  windows 
of  ships  of  war,  and  in  all  cases  where 
glass  is  liable  to  be  broken. 

It  is  much  used  in  optical  experiments, 
and  in  the  manufacture  of  artificial  ultra 
marine. 

MICROCOSMIC  SALT.  A  term  given 
to  a  salt  extracted  from  human  urine,  be- 
cause man  was  regarded  by  the  alche- 
mists as  a  miniature  of  the  world,  or  the 
microcosm.  It  is  a  phosphate  of  soda 
and  ammonia ;  and  is  now  prepared  by 
mixing  equivalent  proportions  of  phos- 
phate of  soda  and  phosphate  of  ammonia, 
each  in  solution,  evaporating  and  crystal- 
lizing the  mixture.  A  small  excess  of 
ammonia  aids  the  crystallization. 

MICROMETER.  An  instrument  ap- 
plied to  telescopes  and  microscopes  for 
measuring  very  small  distances,  or  the 
diameters  of  objects  which  subtend  very 
small  angles.  A  great  number  of  con  • 
trivances  of  various  kinds,  and  depend- 
ing on  different  principles,  have  been 
employed  for  this  purpose  ;  but  it  will  be 
sufficient  to  give  a  general  description  of 
some  of  the  most  useful  or  remarkable 
ones. 

Wire  Micrometer. — This  instrument, 
when  placed  in  the  tube  of  a  telescope,  at 
the  focus  of  the  object  glass,  presents 


Micj 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


365 


the  appearance  represented  in  the  an 
nexed  figure.  A  a  is 
a  spider's  web  line,  or 
very  fine  wire,  fixed  to 
the  diaphragm  ;  and 
B  b  and  C  c  are  similar 
wires  stretched  across 
two  forks,  each  con- 
nected with  a  milled- 
headed  screw.  By 
means  of  these  screws  the  two  wires,  B  b 
and  C  c,  which  are  exactly  parallel  to  each 
other,  are  movable  in  the  direction 
perpendicular  to  A  a  ;  and,  in  order  that 
the  wire  A  a  may  be  placed  in  any  direc- 
tion relatively  to  the  meridian,  there  is 
an  adjusting  screw,  which  works  into  an 
interior  toothed  wheel,  and  turns  the 
apparatus  round  in  its  own  plane  perpen- 
dicular to  the  axis  of  the  telescope. 

The  method  of  using  the  micrometer 
is  as  follows  :  Suppose  the  object  to  be 
accomplished  were  the  measurement  of 
the  angle  of  position  and  distance  of 
two  very  close  stars  ;  the  telegraph  being 
set  and  kept  on  the  objects,  the  microme- 
ter is  turned  by  its  adjusting  screw  until 
the  spider  line  A  a  coincides  with  the 
line  joining  the  two  stars,  or  threads 
them  both  at  the  same  moment.  The 
milled  heads  of  the  screws  which  carry 
the  two  movable  wires,  are  then  turned, 
until  B  b  bisects  one  of  the  two  stars,  and 
C  c  bisects  the  other.  The  observation 
is  now  completed,  and  it  only  remains  to 
ascertain  the  position  and  distance  indi- 
cated by  the  micrometer.  For  the  first 
of  these  purposes,  the  circumference  of 
the  micrometer  is  divided  into  degrees 
and  minutes,  and  read  by  two  verniers  : 
this  reading  gives  the  position  of  A  a  in 
respect  of  the  horizontal  and  vertical 
planes,  and  consequently  the  angle  of 
position  of  the  two  stars.  To  find  their 
distance,  the  head  of  the  screw  which 
carries  one  of  the  movable  wires,  for 
instance  C  e,  is  turned  until  C  c  coincides 
with  B  b  ;  and  the  number  of  revolutions, 
and  parts  of  a  revolution,  required  to 
effect  the  coincidence,  gives  the  distance 
of  the  stars  when  the  value  of  the  scale 
of  the  micrometer  is  known  ;  that  is  to 
say,  when  the  number  of  seconds  of 
space  which  correspond  to  one  revolution 
of  the  screw  is  known.  The  screws  must 
be  made  with  great  accuracy,  and  their 
heads  are  usually  divided  into  60  equal 
parts,  representing  seconds. 

The  value  of  the  scale,  or  of  a  revo- 
lution of  the  screw,  is  obtained  in  the 
following  manner  :  Set  the  two  wires,  B 
b  and  C  c,  apart  to  a  certain  number  of 


revolutions,  and  place  them  in  the  direc- 
tion of  the  meridian.  Observe  the  tran- 
sits of  several  stars  of  known  declina- 
tion over  the  wires  ;  then  multiply  each 
interval  of  seconds  by  15,  and  by  the 
cosine  of  the  star's  declination  ;  and,  ta- 
king the  mean,  you  have  the  seconds  of 
space  which  correspond  to  a  known  num- 
ber of  revolutions  of  the  screw. 

Circular  Micrometer. — This  instrument, 
which  differs  entirely  from  the  above, 
was  first  suggested  by  Boscovich,  in  the 
Leipzic  Acts  for  1740,  and  used  by  Lacaille 
in  observing  a  comet  in  1742  ;  but  seems 
afterwards  to  have  fallen  into  disuse,  un- 
til it  was  revived  by  Dr.  Olbers,  about 
1798.  The  principle  may  be  explained  as 
follows  :  If  the  field  of  a  telescope  be 
perfectly  circular  (which  may  be  effected 
by  means  of  a  diaphragm  turned  in  a 
lathe),  and  if  its  diameter  be  determined 
from  observation,  the  paths  of  two  celes- 
tial bodies  across  the  field  may  be  con- 
sidered as  two  parallel  chords,  which  are 
given  in  terms  of  a  circle  of  known  di- 
ameter. The  differences  of  the  times 
at  which  two  stars  arrive  at  the  middle 
of  their  paths  will  be  their  ascensional 
differences  ;  and  the  distance  between 
the  chords,  which  is  readily  computed 
from  their  lengths,  gives  the  difference 
of  the  declination  of  the  two  bodies. 

The  most  approved  construction  of  the 
annular  micrometer  is  that  of  the  late 
Fraunhofer.  It  consists  of  a  disk  of  par- 
allel plate  glass,  having  in  its  centre  a 
round  hole  of  about  half  an  inch  in  di- 
ameter, to  the  edges  of  which  a  ring  of 
steel  is  cemented,  and  afterwards  truly 
turned  in  a  lathe.  The  disk  being  mount- 
ed in  a  brass  tube,  so  that  it  may  be  ac- 
curately adjusted  in  the  focus  of  the  eye- 
piece, and  applied  to  a  telescope,  the  steel 
ring  is  alone  visible,  and  appears  as  if 
suspended  in  the  atmosphere,  whence 
the  instrument  is  called  the  suspended  an- 
nular micrometer. 

The  micrometer  is  an  instrument  of  the 
utmost  importance  in  astronomy,  and 
one,  in  fact,  to  which  that  science  is  as 
much  indebted  as  to  the  telescope  itself. 
From  a  paper  by  Mr.  Townley,  in  the 
Phil.  Trans,  for  1667,  it  appears  certain 
that  a  micrometer  with  a  movable  wiro 
was  first  constructed  by  an  Englishman, 
Gascoigne,  about  the  year  1640,  and  used 
by  him  for  measuring  the  diameters  ol 
the  moon  and  some  of  the  planets  ;  but 
as  Gascoigne,  who  was  killed  in  the  civil 
wars  in  1644,  published  no  account  of  his 
invention,  the  instrument  was  entirely 
forgotten,  and  the  merit  of  reinventing 


366 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[mil 


it,  and  bringing  it  into  general  use,  be- 
longs to  the  French  astronomer  Azout, 
who  published  a  description  of  it  in  1667. 
Huygens,  a  few  years  previously,  had  con- 
trived to  measure  the  diameter  of  a  planet 
by  inserting  in  the  tube  of  a  telescope,  at 
the  focus  of  the  object-glass  and  eye- 
glass, a  slip  of  metal  which  covered  ex- 
actly the  image  of  the  planet,  and  then 
deducing  the  diameter  from  the  breadth 
of  the  slip,  compared  with  the  diametor 
of  the  field  ;  and  Malvasia  had  employed 
for  the  same  purpose  a  reticle  or  net- 
work of  fine  silver  wires,  crossing  each 
other  at  right  angles,  and  dividing  the 
field  of  the  telescope  into  a  number  of 
equal  squares. 

MICROPHONE.  An  instrument  for 
increasing  the  intensity  of  low  sounds, 
by  subjecting  a  more  sonorous  body  than 
that  which  emits  the  sound  to  be  affected 
by  the  vibrations  of  that  body,  and 
thereby  also  sounding  itself. 

MILDEW.  This  term  is  general- 
ly applied  to  a  particular  mouldy  ap- 
pearance on  the  leaves  of  plants,  which 
is  produced  by  innumerable  minute 
fungi,  which  if  not  checked  in  their 
growth  will  occasion  the  decay  and  death 
of  the  parts  on  which  they  grow,  and 
sometimes  of  the  entire  plant.  In  agri- 
culture, this  appearance  is  frequently 
termed  rust,  ana  sometimes  blight.  It  is 
common  on  wheat,  and  on  the  nop ;  and, 
in  gardens,  on  the  leaves  of  the  peach, 
the  nectarine,  and  other  fruit  trees.  The 
causes  favorable  to  the  production  of 
mildew  are  a  rich  soil  and  a  moist  atmos- 
phere, without  a  free  circulation  of  air  or 
sunshine.  In  agriculture,  this  parasiti- 
cal disease  is  generally  considered  with- 
out remedy  ;  but,  in  gardening,  it  may 
be  checked  by  the  application  of  pow- 
dered sulphur  to  the  leaves  covered  by 
the  fungi,  which  is  found  to  destroy  them 
without  greatly  injuring  the  leaf.  Dry  rot 
is  only  mildew  of  a  more  formidable  kind. 

MILE.  The  Eoman  pace  being  5  feet, 
and  a  Roman  foot  being  equal  to  11-62 
modern  English  inches,  it  follows  that 
the  ancient  Roman  mile  was  equivalent 
to  1614  English  yards,  or  very  nearly 
ll-12ths  of  an  English  statute  mile. 

The  English  statute  mile  was  defined 
(incidentally,  it  would  seem)  by  an  act 
passed  in  the  35th  year  of  the  reign  of 
Queen  Elizabeth,  by  which  persons  were 
forbidden  to  build  within  three  miles  of 
London  ;  and  the  mile  was  declared  to 
be  8  furlongs  of  40  perches  of  16i  feet 
each.  The  statute  mile  is,  therefore,  1760 
yards,  or  5280  feet. 


MILK  owes  its  whiteness  and  opacity 
to  an  emulsion  composed  of  the  caseous 
matter  and  butter,  with  sugar  of  milk, 
extractive  matters,  salts,  and  free  lactic 
acid ;  the  latter  of  which  causes  fresh 
milk  to  redden  litmus  paper.  Milk,  in 
general,  contains  from  10  to  12  per  cent, 
of  solid  matter,  on  being  evaporated  to 
dryness  by  a  steam  heat.  The  mean  spe- 
cific gravity  of  cows'  milk  is  1-030,  but  it 
is  less  if  the  milk  be  rich  in  cream.  The 
specific  gravity  of  the  skimmed  milk  is 
1-035 ;  and  of  the  cream  is  1-0244.  100 
parts  of  creamed  milk  contain — 

Caseous  matter,  containing  some 
butter 2-600 

Sugar  of  milk 3-500 

Alchoholic  extract,  lactic  acid,  and 
lactates 0-600 

Salts  ;  muriate  and  phosphate  of  pot- 
ash, and  phosphate  of  lime 0-425 

Water 92875 

Cream  consists  of— butter  separated 
by  churning 4*5 

Caceous  matter  precipitated  by  the 
coagulation  of  the  milk  of  the  but- 
ter         8-5 

Butter-milk 92-0 

100-0 

When  milk,  contained  in  wire-corked 
bottles,  is  heated  to  the  boiling  point  in 
a  water  bath,  the  oxygen  of  the  included 
small  portion  of  air  under  the  cork  seems 
to  be  carbonated,  and  the  milk  will  after- 
wards keep  fresh,  it  is  said,  for  a  year  or 
two ;  as  green  gooseberries  and  peas  do 
by  the  same  treatment. 

Milk  is  sometimes  adulterated  with  po- 
tato starch,  which  gives  it  a  creamy  con- 
sistence. This  fraud  may  be  detected  by 
pouring  a  few  drops  of  solution  of  iodine 
into  it,  which  immediately  gives  it  a  blue 
or  purple  tint.  Emulsion  of  almonds, 
also  occasionally  used,  may  be  detected 
by  the  taste. 

The  substances  most  commonly  used 
for.  the  purpose  of  adulteration  appear  to 
be  water,  flour,  starch,  and  finely  pow- 
dered chalk. 

On  examining  a  little  of  the  milk  under 
the  microscope,  the  peculiar  granules  of 
starch  and  flour  may  be  readily  seen, 
larger  and  more  oval  than  the  milk  glob- 
ules, if  either  of  these  substances  are  pre- 
sent. Should  any  doubt  exist  as  to  their 
real  nature,  the  addition  of  a  drop  or  two 
of  the  solution  of  iodine  will  impart  to 
the  farina  granules  a  dark  purple  color. 

The  presence,  of  chalk  may  be  still 
more  easily  discovered,  since,  owing  to 
specific  gravity,  it  soon  subsides  to  the 
bottom  of  the  liquid,  where  it  may  at 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


367 


once  be  recognized  by  its  effervescing  on 
the  addition  of  a  little  muriatic  acid. 

We  have  no  chemical  means  of  ascer- 
taining whether  water  has  been  fraudu- 
lently added  to  milk,  the  only  etfect  being 
to  dilute  it  and  render  it  poor  in  quality. 
A  knowledge  of  the  specific  quantity  can- 
not here  be  made  available,  since  the  ab- 
straction of  cream,  which  has  a  lower 
specific  gravity  than  milk,  may  be  made 
to  neutralize  the  effect  produced  by  the 
addition  of  water ;  the  tendency  of  the 
removal  of  the  cream  being  to  raise  the 
specific  gravity  of  the  fluid,  and  that  of 
the  addition  to  lower  it.  A  specimen  of 
milk,  therefore,  which  has  been  impover- 
ished by  the  abstraction  of  its  cream,  and 
still  further  weakened  by  the  addition  of 
water,  may  be  made  to  possess  the  same 
specific  gravity  it  had  when  taken  pure 
from  the  cow. 

A  new  method  of  increasing  the  quan- 
tity of  cream  produced  from  milk,  and 
preserving  milk,  has  been  discovered  by 
Francis  Bernard  Bekaert,  a  citizen  of  Bel- 
gium, and  we  find  it  thus  described  in 
Newton's  London  Journal  for  January, 
1848,  in  an  account  of  a  patent  for  the 
purpose,  taken  out  in  England  : — "  The 
invention  consists,  firstly,  in  a  method  of 
increasing  the  quantity  of  cream  pro- 
duced from  milk,  by  the  addition  of  one 
table-spoonful  of  the  liquid,  hereafter  de- 
scribed, to  every  quart  of  new  milk  ;  the 
milk  is  then  stirred  once  or  twice  round, 
and  left  in  the  pan  or  vessel :  and  the 
skimming  may  take  place  at  the  expira- 
tion of  the  usual  time,  but  the  patentee 
prefers  to  delay  it  a  little.  He  states  that, 
by  the  application  of  the  liquid,  a  much 
larger  quantity  is  forced  to  the  surface  of 
the  milk  than  can  be  obtained  in  the  or- 
dinary way.  The  liquid  is  prepared  by 
adding  to  one  quart  of  water,  one  ounce 
of  the  carbonate  of  soda,  one  tea- spoon- 
ful of  a  solution  of  turmeric  or  curcuma, 
and  three  drops  of  marigold  water. 
When  making  large  quantities  of  the  li- 
quid, it  is  not  requisite  to  weigh  the 
soda,  as  the  same  purpose  is  answered  by 
putting  such  a  quantity  of  soda  into 
water  as  will,  when  dissolved,  on  appli- 
cation of  a  salometer  known  in  Belgium, 
by  the  denomination  of  a  '  p&reset,'  show 
a  density  equal  to  ten  degrees.  The 
soda  is  first  mixed  with  the  water,  and 
then  the  solution  of  turmeric  and  the 
marigold  water  are  added. 

"  The  patentee  claims,  under  this  head 
of  his  invention,  any  salt  of  soda,  when 
mixed  as  before  stated,  and  applied  to 
milk,  for  the  purpose  of  causing  a  larger 


quantity  of  cream  to  rise  to  the  surface 
of  the  milk  than  is  procured  by  the  ordi- 
nary process.  The  soda  and  water  form 
the  basis  of  the  improvement,  the  solu- 
tion of  turmeric  and  marigold  water  be- 
ing only  used  to  improve  the  color  and 
quality  of  the  butter  made  from  the 
cream,  and  not  being  essentially  neces- 
sary to  effect  the  increase  of  the  cream. 
Although  the  patentee  finds  the  use  of 
the  soda  most  convenient,  he  claims  any 
other  alkali  when  applied  in  a  similar 
way. 

"The  second  part  of  the  invention  con- 
sists in  the  following  method  of  preserv- 
ing milk  :  One  table-spoonful  of  a  solu- 
tion of  soda,  made  by  dissolving  one 
ounce  of  carbonate  of  soda  in  a  quart  of 
water,  is  introduced  into  a  quart  bottle, 
nearly  filled  with  new  milk,  only  suffi- 
cient space  having  been  left  for  the 
spoonful  of  liquid ;  after  which  the  bot- 
tle is  corked,  and  a  piece  of  string  put 
round  the  cork  to  prevent  it  from  flying, 
and  then  the  bottles  are  put  into  a  copper 
or  other  vessel  containing  cold  water, 
which  is  to  be  gradually  brought  to  the 
boiling  point.  When  this  has  been 
effected,  the  fire  is  to  be  withdrawn  from 
beneath  the  copper,  or  the  vessel,  if 
movable,  is  to  be  taken  off  the  fire,  and 
the  water  and  the  contents  of  the  bottles 
are  allowed  to  cool ;  the  bottles  are  then 
taken  out  of  the  water  and  packed  away." 

Scarcely  any  idea  can  be  formed  of  the 
immense  quantity  of  milk  produced  in 
the  Union.  In  forming  an  approxima- 
tion to  the  probable  quantity,  the  follow- 
ing, taken  from  the  patent  office  reports 
for  1847  and  1848,  may  afford  some  as- 
sistance : — 

"  We  have  no  precise  data  on  which  to 
found  an  extended  estimate,  for  in  none 
of  the  census  returns  of  the  States  do  we 
find  the  number  of  milch  cows  specified. 
But  in  the  state  of  New  York,  in  1845, 
the  amount  of  butter  reported  as  made 
was  about  80,000,000,  and  that  of  cheese 
36,000,000  pounds. 

'*  Were  we  to  allow  for  every  pound  of 
butter  25  pounds  of  milk,  which  is  pro- 
bably a  low  average,  and  reckon  these  at 
about  10  or  12  quarts,  this  would  give 
800,000,000  or  more  quarts,  or  200,000,000 
gallons  of  milk.  But  considering  the 
proportion  of  milk  used  for  butter  as 
one-half  throughout  the  whole  State,  and 
this  would  give  for  the  single  State  of 
New  York,  not  less  than  400,000,000  of 
gallons  of  milk  used,  besides  what  is  ap- 
plied to  butter  and  cheese ;  and  were 
this  reckoned  at  only  2  cents  per  quart, 


368 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[MIL 


would  be  the  sum  of  $32,000,000,  while 
the  butter,  at  only  10  cents  per  pound, 
and  the  cheese  at  5  cents  per  pound,  a 
low  estimate  for  each,  would  amount  to 
$8,000,000  for  butter,  and  the  cheese  to 
$1,800,000,  making  the  aggregate  of  the 
milk  product  of  the  single  state  of  New 
York,  at  a  very  low  estimate,  at  least 
$40,000,000,000,  equal  to  two-thirds  of 
the  cotton  crop  of  the  United  States. 

"  According  to  the  census  of  the  United 
States  in  1840,  the  number  of  neat  cattle, 
including  all  kinds,  was  for  Pennsylvania 
and  Ohio  each  about  one-quarter  less 
than  in  New  York.  As  it  is  believed 
that  the  number  of  oxen  used  in  New 
York  is  greater  than  in  Pennsylvania  and 
Ohio,  supposing  a  similar  ratio  to  hold 
good,  and  modified  hy  this  last  consider- 
ation in  these  two  States  with  respect  to 
milch  kine,  we  may  probably  consider 
the  milk  product  of  each  of  the  States  of 
Pennsylvania  and  Ohio,  then,  at  about 
one-fifth  less  than  in  New  York.  It  is 
very  probable,  however,  that  the  propor- 
tion would  be  less  with  respect  to  Ohio 
at  the  present  time.  But,  allowing  it  as 
we  have  mentioned,  we  must  consider 
the  milk  products  of  Pennsylvania  and 
Ohio  equal  to  at  least  $64,000,000,  and 
the  aggregates  for  these  States  and  New 
York  "would  be  equal  to  over  $100,000,000. 
Were  this  estimate  to  be  extended  to  the 
other  States,  the  amount  in  value  must 
be  enormous." 

The  quantity  of  milk  sold  in  our  cities 
is  great.  Some  idea  of  it  may  be  formed 
from  the  fact  that  50,000  quarts  of  milk 
daily  are  carried  on  the  Erie  railroad, 
equal,  including  the  cans,  to  sixty-three 
tons,  not  less,  probably,  than  15,000,000 
or  16,000,000  quarts  a-year,  which  did 
not  find  its  way  to  New  York  before  the 
road  was  constructed. 

MILLS  are,  in  the  original  sense,  estab- 
lishments for  grinding  grain,  &c,  but  the 
word  is  often  synonymous  with  factory  or 
manufactory,  and  applied  to  any  thing 
wrought  by  machinery. 

Flour  nulls  have,  for  ages,  been  wrought 
by  water  and  wind,  but  latterly  steam 
has  been  applied.  The  principle  is  the 
same  in  all,  the  rotation  ot  a  stone  in  jux- 
taposition with  a  fixed  one,  with  hopper 
for  supply,  and  bolter  for  sifting.  Doubts 
being  entertained  of  the  integrity  of  many 
millers,  various  mills  for  domestic  grind- 
ing have  been  invented,  as  Stockdale's 
and  Rustall's,  with  detached  bolters. 
Rustall's  consists  of  vertical  stones  of  30 
inches,  one  of  which  is  turned  by  a  winch, 
and  altogether  most  complete,  and  his 


I  bolter  is  equally  excellent.  It  has  been 
I  adopted  in  prisons,  workhouses,  barracks, 
\  and  other  establishments. 

The  grain  falls  from  the  hopper  into 
the  eye  of  the  upper  mill-stone,  and  by 
I  its  revolution  is  passed  between  the 
I  stones,  and  thrown  out,  as  flour,  meal, 
or  malt.  The  number  of  revolutions  in  a 
minute  ought  to  be  450,  divided  by  the 
diameter  in  feet. 

An  upper  stone,  of  six  feet,  contains 
about  22*  cubic  feet,  at  840  or  850  lbs.  to 
the  foot,  and  its  revolutions  about  75  per 
minute.  The  water-wheel  may  be  18  feet, 
if  the  floats  move,  with  a  third  of  the  ve- 
locity of  the  stream. 
A  sack  of  wheat  per  hour  may  be 

S round  with  a  power  able  to  raise  900 
>s.  70  feet  per  minute ;  for  2,  3,  or  4 
sacks,  the  power  rises  in  less  ratio  than 
the  multiple,  i.  e.  2100  lbs.  at  70  feet, 
would  grind  three  sacks  of  rye  or  wheat. 

To  grind  3  sacks  per  hour  requires  a 
cylinder  of  a  steam-engine  of  20  inches, 
and  1  sack  a  cylinder  of  12*5  inches.  To 
do  the  same  work,  3  and  1  sack,  with  an 
overshot  water-wheel  of  12  feet,  requires 
1600  and  660  imperial  gallons  of  water; 
with  a  wheel  of  16  feet,  1200  and  500  im- 
perial gallons ;  or  with  a  wheel  of  24  feet, 
800  gallons  and  330  per  minute. 

In  a  corn-mill,  there  are  three  depart- 
ments. 1.  The  revolving  sieve  and  fan, 
to  clean  the  corn  before  it  descends  to 
the  hopper.  2.  The  hopper  and  the 
stones.  3.  The  cooler  and  vibrating  bol- 
ter, where  it  is  dressed.  A  system  of 
buckets  raises  the  grain  to  the  sieve,  and 
the  flour  to  the  bolter,  by  various  appli- 
cations of  the  moving  power. 

Bigelow  proposes  to  make  holes  in  the 
cap  or  running- wheel,  to  prevent  the 
heating  or  clogging  of  the  meal,  in  cases 
of  increased  velocity. 

Mill-stones  are  hard  grit  or  granite- 
stones,  cut  into  grooves  in  octagonal  sec- 
tions, so  as  to  cross  each  other  in  work- 
ing, and  make  the  grain  pass  over  the 
largest  surface.  Eight  radii,  at  45°,  are 
first  grooved  with  a  double  hammer,  pick, 
and  chisel,  and  then  six  other  roads  or 
grooves  are  chisselled  and  picked  parallel 
to  each  of  these  radii ;  the  stones  then 
work  parallel.  Some  work  right-handed, 
others  left-handed,  but  the  grooves  must 
tally. 

Flax  mills  are  water-mills,  which  turn 
rollers  for  bruising  the  rough  flax,  and 
revolving  or  turning  spikes  or  scutchers 
to  clear  the  flax  presented  to  them.  For- 
ty aws  for  the  water-wheel,  and  102  cops 
for  the  power,  moving  another  with  25 


mil] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


360 


teeth  for  tne  middle  roller,  are  the  pro-  j 
portions  of  Gray. 

Flatting  mills  for  reducing  metal  to  | 
plates,  are  rollers  turned  by  horses,  or 
steam-power,  through  which  the  metal  is  i 
passed  and  repassed.  The  distances  of 
the  rollers  are  adjusted  by  screws,  turned 
by  pinions.  Lead,  copper,  and  silver  are 
rolled  thus,  and  copper  is  silvered  by  rol- 
ling a  thin  plate  of  silver  fixed  to  a  thick 
one  of  copper,  and,  by  repeatedly  passing 
through  the  rollers,  constantly  narrower 
or  closer,  a  perfect  thin  sheet  of  silvered 
copper  is  produced  which  may  be  cut  or 
stamped  tor  plated  ware,  or  other  pur- 
noses. 

A  sugar  mill  is  formed  by  three  upright 
rollers,  the  one  moving,  and  the  side 
ones  fixed,  or  sometimes  the  three  mov- 
ing. The  rollers  are  turned  by  mules, 
water,  or  steam-power,  and  the  canes  are 
placed  between  the  rollers  by  hand.  The 
expressed  juice  runs  into  a  trough,  and 
thence  into  a  reservoir. 

The  following  calculations  may  be  use- 
fully given  under  the  head  of  mill  opera- 
tions: In  an  undershot  water-wheel,  the 
quantity  is  the  velocity  in  a  second  into 
the  area  of  the  water-way.  And  the 
power  is  the  quantity  into  the  weight  of 
a  cubic  inch  of  water,  and  the  velocity. 
The  power  is  to  the  effect  produced,  as 
10  to  3-62. 

In  an  overshot  wheel,  the  power  is  the 
product  of  the  descent  from  the  head  to 
the  bottom,  and  the  weight  of  the  water 
expended  in  a  second.  The  power  is  to 
the  effect  as  10  to  6'6. 

The  velocity  at  a  maximum  load  is 
three  feet  in  a  second. 

The  velocity  is  the  square  root  of  the 
space  fallen  through.  For  the  same 
stream  falling,  turns  a  wheel  57  times  in 
a  minute,  and  directed  to  the  centre  as 
in  an  undershot  wheel,  turns  it  but  38-5 
times,  which  are  as  1  to  1*414,  the  square 
root  of  1  and  2  nearly. 

Therefore,  the  velocities  will  be  as  the 
square  roots  of  their  diameters,  in  all 
overshot  wheels. 

Portable  horse  mills. — The  horse  is  at- 
tached to  the  extremity  of  a  cast-iron  le- 
ver, which  puts  in  motion  a  large  hori- 
zontal wheel,  the  upright  axis  of  which 
is  sunk  into  the  earth,  and  having  a 
groove  around  its  rim,  which  is  armed 
with  points  of  iron ;  these  points  enter 
the  links  of  a  chain,  which  passes  around 
the  great  wheel,  and  through  two  cast- 
iron  trunks,  or  tubes,  which  are  buried 
in  the  earth,  under  the  horse-walk.  This 
chain  very  conveniently  communicates 
16* 


the  motion  to  any  distance,  and  in  any 
direction  required;  and  either  of  each 
may  be  varied  ad  infinitum,  without  much 
loss  of  time,  or  the  employment  of  any 
considerable  quantity  of  materials.  Two 
men  only  were  able  to  re-estabiish  a  mill 
in  the  course  of  an  hour,  in  a  fresh  situa- 
tion in  the  open  air.  The  horse  is  at- 
tached to  the  outer  end  of  the  lever,  by 
means  of  a  swingle-tree  and  traces,  which 
should  be  as  short  as  possible. 

Mr.  Bogardus,  of  New  York,  has  in- 
vented an  universal  eccentric  mill  for 
wheeling,  cutting,  and  grinding,  which 
is  one  ot  the  most  useful  and  important 
inventions  of  the  time.  His  patent  has 
been  extended  by  special  act  of  Congress 
14  years,  in  consideration  of  its  great 
merit. 

In  Mr.  Bogardus's  mill  the  principle  is 
entirely  new,  both  plates  revolve  in  the 
same  direction  (with  nearly  equal  speed) 
on  centres,  which  are  apart  from  each 
other  one  inch,  more  or  less  ;  the  centre 
of  the  one,  or  axis  thereto  affixed,  resting 
on,  or  revolving  upon  a  stationary  point, 
whilst  the  prime  mover,  by  means  of  a 
belt  or  gearing,  communicates  motion  to 
the  other  plate.  The  circles  which  are 
cut  in  the  plates  act  like  revolving  shears, 
cutting  every  way,  which,  when  in  opera- 
tion, causes  a  peculiar  cutting,  wrench- 
ing or  twisting,  and  sliding  motion,  ad- 
mirably adapted  for  every  species  of 
grinding.  From  the  position  of  the  two 
centres  it  is  named  the  eccentric  mill. 
The  following  are  some  of  its  advantages  : 

1.  The  peculiar  motion  of  the  plates 
will  of  itself  discharge  the  ground  sub- 
stance* so  that  many  substances  can  be 
ground  thereby  which  would  altogether 
choke  other  mills. 

2.  In  other  mills,  a  given  point  in  one 
of  the  plates  continually  describes  the 
same  circle  on  the  other;  but  in  this 
mill  it  traverses  on  the  other  plate  at  an 
infinite  variety  of  angles,  every  point 
withiu  two  concentric  circles  apart  from 
each  other  twice  the  distance  of  the  cen- 
tres of  the  plates,  thereby  rendering  the 
wear  and  tear  of  the  plates  uniform,  and 
preserving  the  grinding  action  of  every 
point. 

3.  In  other  mills  the  grinding  power  of 
each  point  increases  with  its  distance  from 
the  centre ;  I5ut  in  this  mill  every  point, 
from  the  centre  to  the  circumference,  has 
the  same  grinding  power.  A  consider- 
ably smaller  mill  will  therefore  effect  a 
given  purpose,  and  the  eccentric  mill  is 
therefore  more  portable  than  other  mills. 

4.  The  ever  changing  action  of  the  mUJ 


370 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[MIS 


and  the  quick  discharge  of  the  substance 
ground  prevented  from  becoming  heated, 
so  that  the  eccentric  mill  may  be  profit- 
ably employed  in  grinding  substances 
which,  in  other  mills,  would  be  either 
spoiled  or  deteriorated  in  quality,  or,  by 
their  melting,  be  impossible  to  be  ground. 
If  other  mills  were  driven  with  that  speed 
which  can  be  safely  applied  to  the  eccen- 
tric mill,  they  would  be  made  red-hot  in 
a  few  minutes. 

Bogardus's  mills  have  been  successful- 
ly introduced  for  the  following  purposes : 
Hulling  rice,  coffee,  and  olives.  Grind- 
ing grain  of  all  kinds ;  paints  of  all  kinds, 
in  water  or  oil :  iron,  zinc,  copper,  and 

fold  ores,  plumbago  and  manganese; 
ones  for  manure,  and  bones  for  sugar 
refining,  flint  and  quartz,  charcoal,  plas- 
ter, putty,  printers'  inks,  drugs  and.  dye- 
stuffs  ;  snuffs,  mustard,  coffee,  spices, 
loaf-sugar,  starch,  gums,  resins,  asphalt- 
um,  india-rubber,  flax-seed,  and  oil-cake. 

MILL-STONE,  or  Buhb -Stone.  This 
interesting  form  of  silica,  which  occurs 
in  great  masses,  has  a  texture  essentially 
cellular,  the  cells  being  irregular  in  num- 
ber, shape,  and  size,  and  are  often  cross- 
ed by  thin  plates,  or  coarse  fibres  of  silex. 
The  buhr-stone  has  a  straight  fracture, 
but  it  is  not  so  brittle  as  flint,  though  its 
hardness  is  nearly  the  same.  It  is  feebly 
translucent;  its  colors  are  pale  and  dead, 
of  a  whitish,  grayish,  or  yellowish  cast, 
sometimes  with  a  tinge  of  blue. 

The  buhr-  stones  usually  occur  in  beds, 
which  are  sometimes  continuous,  and  at 
others  interrupted.  These  beds  are 
placed  amid  deposites  of  sand,  or  argilla- 
ceous and  ferruginous  marls,  which  pene- 
trate between  them,  filling  their  fissures 
and  honeycomb  cavities.  Buhr-stones 
constitute  a  very  rare  geological  forma- 
tion, being  found  in  abundance  only  in 
the  mineral  basin  of  Paris,  and  a  few' ad- 
joining districts.  Its  place  of  superposi- 
tion is  well  ascertained :  it  forms  a  part 
of  the  lacustrine,  or  fresh-water  forma- 
tion, which,  in  the  locality  alluded  to, 
lies  above  the  fossil-bone  gypsum,  and 
the  stratum  of  sand  and  marine  sandstone 
which  covers  it.  Buhr-stone  constitutes, 
therefore,  the  uppermost  solid  stratum  of 
the  crust  of  the  globe  ;  for  above  it  there 
is  nothing  but  alluvial  soil,  or  diluvial 
gravel,  sand,  and  loam. 

Buhr-stones  sometimes  contain  no  or- 
ganic forms,  at  others  they  seem  as  if 
stuffed  full  of  fresh-water  shells,  or  land 
Bhells,  and  vegetables  of  inland  growth. 
There  is  no  exception  known  to  this  ar- 
rangement ;  but  the  shells  have  assumed 


a  silicious  nature,  and  their  cavities  are 
often  bedecked  with  crystals  and  quart?:. 
The  best  buhr-stones  for  grinding  corn, 
have  about  an  equal  proportion  of  solid 
matter,  and  of  vacant  space.  The  finest 
quarry  of  them  is  upon  the  high  ground, 
near  La  Ferte-sous-Jouarre.  The  stones 
are  quarried  in  the  open  air,  and  are  cut 
out  in  cylinders,  from  one  to  two  yards 
in  diameter,  by  a  series  of  iron  and  wood- 
en wages,  gradually  but  equally  inserted. 
The  pieces  of  buhr-stones  are  afterwards 
cutinparallelopipeds,  called  panes,  which 
are  bound  with  iron  hoops  into  large 
millstones.  These  pieces  are  exported 
chiefly  to  England  and  America.  Good 
millstones  of  a  bluish  white  color,  with  a 
regular  proportion  of  cells,  when  six  feet 
and  a  half  in  diameter,  fetch  1200  francs 
a-piece,  or  $220.  A  coarse  conglomerate 
sandstone  or  breccia  is,  in  some  cases, 
used  as  a  substitute  for  buhr-stones ;  but 
it  is  a  poor  one. 

Very  good  buhr  millstones  are  now 
sent  from  Georgia  and  Arkansas,  which 
are  said  to  equal  the  French  stone  in 
quality.  A  set  of  51  feet  Georgia  stones 
have  been  put  up  in  the  mills  of  Hacks- 
hall,  Bro.  &  Co.,  at  Richmond,  Virginia. 

MINE.  The  name  given  generally  to 
every  system  of  subterraneous  work  or 
excavation  which  has  for  its  object  the 
discovery  and  extraction  of  the  metallic 
ores  or  other  mineral  produce.  But  in 
addition  to  the  underground  works  which 
constitute  the  mine  properly  so  called, 
the  term  usually  comprehends  also  the 
ground  on  the  surface,  together  with  the 
numerous  appendages  which  are  requir- 
ed there ;  as  steam-engines,  water-wheels, 
and  other  machinery  for  drainage,  the 
extraction  of  the  ores,  and  their  mechan- 
ical preparation,  with  various  buildings 
and  erections.  The  subject  of  mines  is 
one  of  the  most  important  within  the 
whole  range  of  human  knowledge  :  their 
contents  constitute  the  main-springs  of  ci- 
vilization ;  and  the  means  employed  to  ob- 
tain them  are  to  be  ranked  among  the  most 
extraordinary  instances  of  human  enter- 
prise, patience,  and  ingenuity.  The  art  of 
mining  has  been  practised  from  the  earliest 
antiquity,  and  has  formed  a  branch  of 
industry  to  the  most  barbarous  as  well 
as  the  most  civilized  communities.  It  is 
true  that  we  can  scarcely  dignify  by  the 
name  of  mining  the  operation  by  which 
the  savage  merely  collects  grains  of  gold 
in  the  sands  of  rivers,  or  extracts  it  by 
pounding,  when  mechanically  combined 
with  other  substances ;  but  even  this 
simple    operation    becomes    interesting 


min] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


871 


when  viewed  as  the  first  link  in  the 
chain  of  those  elaborate  and  scientific 
processes  which  result  in  placing  at  our 
disposal  the  metal  of  any  ore,  no  matter 
how  refractory. 

In  the  lodes,  or  veins,  the  principal 
matters  which  till  them  are  to  be  distin- 
guished from  the  accessory  substances  ; 
the  latter  being  distributed  irregularly, 
amidst  the  mass  of  the  first,  in  crystals, 
nodules,  grains,  seams,  &c.  The  non- 
metalliferous  exterior  portion,  which  is 
often  the  largest,  is  called  gangue,  from 
the  German  gang,  vein.  The  position  of 
a  vein  is  denoted,  like  that  of  the  strata, 
by  the  angle  of  inclination,  and  the 
point  of  the  horizon  towards  which  they 
dip,  whence  the  direction  is  deduced. 

Veins  are  merely  small  lodes,  which 
sometimes  traverse  the  great  ones,  rami- 
fying in  various  directions,  and  in  differ- 
ent degrees  of  tenuity. 

A  metalliferous  substance  is  said  to  be 
disseminata^  when  it  is  dispersed  in 
crystals,  spangles,  scales,  globules,  &c, 
through  a  large  mineral  mass. 

Certain  ores  which  contain  the  metals 
most  indispensable  to  human  necessities, 
have  been  treasured  up  by  the  Creator  in 
very  bountiful  deposites  :  constituting 
either  great  masses  in  rocks  of  different 
kinds,  or  distributed  in  lodes,  veins, 
nests,  concretions,  or  beds  with  stony 
and  earthy  admixtures  ;  the  whole  of 
which  become  the  objects  of  mineral  ex- 
ploration. These  precious  stores  occur 
in  different  stages  of  the  geological  for- 
mations; but  their  main  portion,  after 
having  existed  abundantly  in  the  several 
orders  of  the  primary  strata,  suddenly 
cease  to  be  found  towards  the  middle  of 
the  secondary.  Iron  ores  are  the  only 
ones  which  continue  among  the  more 
modern  deposites,  even  so  high  as  the 
beds  immediately  beneath  the  chalk, 
when  they  also  disappear,  or  exist  merely 
as  coloring  matters  ol  the  tertiary  earthy 
beds. 

The  strata  of  gneiss  and  mica-slate 
constitute  in  Europe  the  grand  metallic 
domain.  There  is  hardly  any  kind  of 
ore  which  does  not  occur  there  in  suffi- 
cient abundance  to  become  the  object  of 
mining  operations,  and  many  are  found 
nowhere  else.  The  transition  rocks,  and 
the  lower  part  of  the  secondary  ones,  are 
not  so  rich,  neither  do  they  contain  the 
same  variety  of  ores.  But  this  order  of 
things,  which  is  presented  by  Great 
Britain,  Germany,  France,  Sweden,  and 
Norway,  is  far  from  forming  a  general 
iaw  ;   since  in  equinoctial  America  the 


gneiss  is  but  little  metalliferous ;  while 
the  superior  strata,  such  as  the  clay- 
schists,  the  sicnitic  porphyries,  the  lime- 
stones, which  complete  the  transition 
series,  as  also  several  secondary  depo- 
sites, include  the  greater  portion  of  the 
immense  mineral  wealth  of  that  region  of 
the  globe. 

All  the  substances  of  which  the  ordi- 
nary metals  form  the  basis,  are  not 
equally  abundant  in  nature  ;  a  great  pro- 
portion of  the  numerous  mineral  species 
which  figure  in  our  classifications,  are 
mere  varieties  scattered  up  and  down  in 
the  cavities  of  the  great  masses  or  lodes. 
The  workable  ores  are  few  in  number, 
being  mostly  sulphurets,  some  oxides, 
and  carbonates.  These  occasionally  form 
of  themselves  very  large  masses,  but 
more  frequently  they  a.*e  blended  with 
lumps  of  quartz,  feldspar,  and  carbonate 
of  lime,  which  form  the  main  body  of 
the  deposit ;  as  happens  always  in  pro- 
per lodes.  The  ores  in  that  case  are  ar- 
ranged in  small  layers  parallel  to  the 
strata  of  the  formation,  or  in  small  veins 
which  traverse  the  rock  in  all  directions, 
or  in  nests  or  concretions  stationed  ir- 
regularly, or  finally  disseminated  in  hard- 
ly visible  particles.  These  deposites 
sometimes  contain  apparently  only  one 
species  of  ore,  sometimes  several,  which 
must  be  mined  together,  as  they  seem  to 
be  of  contemporaneous  formation ;  whilst, 
in  other  cases,  they  are  separable,  hav- 
ing been  probably  formed  at  different 
epochs. 

The  following  general  observations  on 
the  localities  of  ores,  and  on  the  indica- 
tions of  metallic  mines,  show  their  dis- 
positions in  various  geological  forma- 
tions. 

1.  Tin  exists  principally  in  primitive 
rocks,  appearing  either  in  interlaced 
masses,  in  beds,  or  as  a  constituent  part 
of  the  rock  itself,  and  more  rarely  in  dis- 
tinct veins.  Tin  ore  is  found  indeed 
sometimes  in  alluvial  land,  filling  up  low 
situations  between  lofty  mountains. 

2.  Gold  occurs  either  in  beds  or  in 
veins,  frequently  in  primitive  rocks ; 
though  in  other  formations,  and  particu- 
larly in  alluvial  earth,  it  is  also  found. 
When  this  metal  exists  in  the  bosom  ot 
primitive  rocks,  it  is  particularly  in 
schists ;  it  is  not  found  in  serpentine, 
but  it  is  met  with  in  graywacke  in  Tran- 
sylvania. The  gold  of  alluvial  districts, 
called  gold  of  washing  or  transport,  oc- 
curs, as  well  as  alluvial  tin,  among  the 
debris  of  the  more  ancient  rocks. 

3.  Silver  is  found  particularly  ia  veins 


372 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[min 


%nd  beds,  in  primitive  and  transition  for- 
mations ;  though  some  veins  of  this 
metal  occm  in  secondary  strata.  The 
rocks  richest  in  it  are  gneiss,  mica-slate, 
clay-slate,  graywacke,  and  old  alpine 
limestone.  Localities  of  silver-ore  itself 
are  not  numerous,  at  least  in  Europe, 
among  secondary  formations  ;  but  it  oc- 
curs in  combination  with  the  ores  of  cop- 
per or  of  lead. 

4.  Copper  exists  in  the  three  mineral 
epochas ;  first,  in  primitive  rocks,  prin- 
cipally in  the  state  of  pyritous  copper,  in 
beds,  in  masses,  or  in  veins  ;  second,  in 
transition  districts,  sometimes  in  masses, 
sometimes  in  veins  of  copper  pyrites ; 
third,  in  secondary  strata,  especially  in 
beds  of  cupreous  schist. 

5.  Lead  occurs  also  in  each  of  the 
three  mineral  epochas;  abounding  par- 
ticularly in  primitive  and  transition 
grounds,  where  it  usuallv  constitutes 
veins,  and  occasionally  beds  of  sulphu- 
retted lead  (galena).  The  same  ore  is 
found  in  strata  or  in  veins  among  secon- 
dary rocks,  associated  now  and  then  with 
ochreous  iron-oxide  and  calamine  (car- 
bonate of  zinc) ;  and  it  is  sometimes  dis- 
seminated in  grains  through  more  recent 
strata. 

6.  Iron  is  met  with  in  four  different 
mineral  eras,  but  in  different  ores. 
Among  primitive  rocks,  magnetic  iron 
ore  and  specular  iron  ore  occur  chiefly  in 
beds,  sometimes  of  enormous  size ;  the 
ores  of  red  or  brown  oxide  of  iron  (hema- 
tite) are  found  generally  in  veins,  or  oc- 
casionally in  masses  with  sparry  iron, 
both  in  primitive  and  transition  rocks ; 
as  also  sometimes  in  secondary  strata; 
but  more  frequently  in  the  coal-measure 
strata,  as  beds  of  clay-ironstone,  of  glob- 
ular iron,  oxide,  and  carbonate  of  iron. 
In  alluvial  districts  we  find  a  cross  clay- 
iron  stone,  granular  iron-ore,  bog-ore, 
swamp-ore,  and  meadow-ore.  The  iron 
ores  which  belong  to  the  primitive  period 
have  almost  always  the  metallic  aspect, 
with  a  richness  amounting  even  to  80 
per  cent,  of  iron,  while  the  ores  in  the 
posterior  formations  become  in  general 
more  and  more  earthy,  down  to  those  in 
alluvial  soils,  some  of  which  present  the 
appearance  of  a  common  stone,  and  afford 
not  more  than  20  per  cent,  of  metal, 
though  its  quality  is  often  excellent. 

7.  Mercury  occurs  principally  among 
secondary  strata,  in  disseminated  masses, 
along  with  combustible  substances ; 
though  the  metal  is  met  with  occasion- 
ftlly  in  primitive  countries. 

8.  GobaU  belongs  to  the  three  mineral 


epochas  ;  its  most  abundant  deposits  are 
veins  in  primitive  rocks;  small  veins 
containing  this  metal  are  found,  however, 
in  secondary  strata. 

9.  Antimony  occurs  in  veins  or  beds 
among  primitive  transition  rocks. 

10,  11.  Bismuth  and  nickel  do  not  ap- 
pear to  constitute  the  predominating 
substance  of  any  mineral  deposits ;  but 
they  often  accompany  cobalt. 

12.  Zinc  occurs  in  the  three  several 
formations :  namely,  as  sulphuret  or 
blende,  particularly  in  primitive  and 
transition  rocks  ;  as  calamine,  in  secon- 
dary strata,  usually  along  with  oxide  of 
iron,  and  sometimes  with  sulphuret  of 
lead. 

An  acquaintance  with  the  general  re- 
sults collected  and  classified  by  geology 
must  be  our  firstguide  in  the  investiga- 
tion of  mines.  This  enables  the  obser- 
ver to  judge  whether  any  particular  dis- 
trict should,  from  the  nature  and  arrange- 
ment of  its  rocks,  be  susceptible  of  in- 
cluding within  its  bosom,  beds  of  work- 
able ores  ;  it  indicates  also,  to  a  certain 
degree,  what  substances  may  probably  be 
met  with  in  a  given  series  of  rocks,  and 
what  locality  these  substances  will  pre- 
ferably effect.  For  want  of  a  knowledge 
of  these  facts,  many  persons  have  gone 
blindly  into  researches  equally  absurd 
and  ruinous. 

Formerly,  indications  of  mines  were 
taken  from  very  unimportant  circum- 
stances ;  from  thermal  waters,  the  heat 
of  which  was  gratuitously  referred  to  the 
decomposition  of  pyrites ;  from  mineral 
waters,  whose  course  is  however  often 
from  a  far  distant  source:  from  vapors 
incumbent  over  particular  mountain 
groups  ;  from  the  snows  melting  faster 
in  one  mineral  district  than  another; 
from  the  different  species  of  forest  trees, 
and  from  the  greater  or  less  vigor  of 
vegetation,  &c.  In  general,  all  such  in- 
dications are  equally  fallacious  with  the 
divining  rod,  and  the  compass  made  of  a 
lump  of  pyrites  suspended  by  a  thread. 

Gunpowder  is  the  most  valuable  agent 
of  excavation  ;  possessing  a  power  which 
has  no  limit,  and  which  can  act  every 
where,  even  under  water.  Its  introduc- 
tion, in  1615,  caused  a  great  revolution  in 
the  mining  art.  Gun-cotton  is  equally 
valuable. 

It  is  employed  in  mines  in  different 
manners,  and  in  different  quantities,  ao^ 
cording  to  circumstances.  In  all  cases, 
however,  the  process  resolves  itself  into 
boring  a  hole,  and  enclosing  a  cartridge 
in  it,  which  is  afterwards  made  to  ex- 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


373 


plode.  The  hoe  is  always  cylindrical, 
and  is  usually  made  by  means  of  the 
borer,  a  stem  of  iron,  terminated  by  a 
blunt-edged  chisel.  It  sometimes  ends 
in  a  cross,  formed  by  two  chisels  set 
transversely.  The  workman  holds  the 
stem  in  his  left  hand,  and  strikes  it  with 
an  iron  mallet  held  in  his  right.  He  is 
careful  to  turn  the  punch  a  very  little 
round  at  every  stroke.  Several  punches 
are  employed  in  succession,  to  bore  one 
hole ;  the  first  shorter,  the  latter  ones 
longer,  and  somewhat  thinner.  The  rub- 
bish is  withdrawn  as  it  accumulates,  at 
the  bottom  of  the  hole,  by  means  of  a 
picker,  which  is  a  small  spoon  or  disk  of 
iron  fixed  at  the  end  of  a  slender  iron 
rod.  When  holes  of  a  large  size  are  to 
be  made,  several  men  must  be  employed ; 
one  to  hold  the  punch,  and  one  or  more 
to  wield  the  iron  mallet.  The  perfora- 
tions are  seldom  less  than  an  inch  in 
diameter,  and  18  inches  deep  •  but  they 
are  sometimes  two  inches  wide,  with  a 
depth  of  50  inches. 

The  gunpowder,  when  used,  is  most 
commonly  put  up  in  paper  cartridges. 
Into  the  side  of  the  cartridge,  a  small  cy- 
lindrical spindle  or  piercer  is  pushed.  In 
this  state  the  cartridge  is  forced  down  to 
the  bottom  of  the  hole,  which  is  then 
stuffed,  by  means  of  the  tamping  bar, 
with  bits  of  dry  clay,  or  friable  stones 
coarsely  pounded.  The  piercer  is  now 
withdrawn,  which  leaves  in  its  place  a 
channel  through  which  fire  may  be  con- 
veyed to  the  charge.  This  is  executed 
cither  by  pouring  gunpowder  into  that 
passage,  or  by  inserting  into  it  reeds, 
straw  stems,  quills,  or  tubes  of  paper 
filled  with  gunpowder.  This  is  exploded 
by  a  long  match,  which  the  workmen  kin- 
dle, and  then  retire  to  a  place  of  safety. 

As  the  fiercer  must  not  only  be  slender 
but  stiff,  so  as  to  be  easily  withdrawn 
when  the  hole  is  stamped,  iron  spindles 
are  usually  employed,  though  they  oc- 
casionally give  rise  to  sparks,  and  conse- 
quently to  dangerous  accidents,  by  their 
friction  against  the  sides  of  the  hole. 
Brass  piercers  have  been  sometimes  tried ; 
but  they  twist  and  break  too  readily. 

Each  hole  bored  in  a  mine,  should  be 
so  placed  in  reference  to  the  schistose 
structure  of  the  rock,  and  to  its  natural 
fissures,  as  to  attack  and  blow  up  the 
least  resisting  masses.  Sometimes  the 
rock  is  prepared  beforehand  for  splitting 
in  a  certain  direction,  by  means  of  a 
Barrow  channel  excavated  with  the  small 
hammer. 

The  quantity  of  gunpowder  should  be 


proportional  to  the  depth  of  the  hole,  and 
the  resistance  of  the  rock,  and  merely 
sufficient  to  split  it.  Any  thing  additional 
would  serve  no  other  purpose  than  to 
throw  the  fragments  about  the  mine, 
without  increasing  the  useful  effect.  Into 
the  holes  of  about  an  inch  and  a  quarter 
diameter,  and  18  inches  deep,  only  two 
two  ounces  of  gunpowder  are  put. 

It  appears  that  the  effect  of  the  gun- 
powder may  be  augmented  by  leaving  an 
empty  space  above,  in  the  middle  of, 
or  beneath  the  cartridge.  In  the  mines  of 
Silesia,  the  consumption  of  gunpowder 
has  been  eventually  reduced,  without 
diminishing  the  product  of  the  blasts,  by 
mixing  sawdust  with  it,  in  certain  pro- 
portions. The  hole  has  also  been  filled 
up  with  sand  in  some  cases,  according  to 
Mr.  Jessop's  plan,  instead  of  being  packed 
with  stones,  which  has  removed  the  dan- 
ger of  the  tamping  operation.  The  ex- 
periments made  in  this  way  have  given 
results  very  advantageous  in  quarry 
blasts  with  great  charges  of  gunpowder ; 
but  less  favorable  in  the  small  charges 
employed  in  mines. 

Water  does  not  oppose  an  insurmount- 
able obstacle  to  the  employment  of  gun- 
powder ;  but  when  the  hole  cannot  be 
made  dry,  a  cartridge  bag,  impermeable 
to  water,  must  be  had  recourse  to,  pro- 
vided with  a  tube  also  impermeable,  in 
which  the  fiercer  is  placed. 

After  the  explosion  of  each  mining 
charge,  wedgers  aud  levers  are  employed, 
to  drag  away  and  break  down  what  has 
been  shattered. 

Wherever  the  rock  is  tolerably  hard, 
the  use  of  gunpowder  is  more  economical 
and  more  rapid  than  any  tool-work,  and 
is  therefore  always  preferred.  A  gallery, 
for  example,  a  yard  and  a  half  high,  and 
a  yard  wide,  the  piercing  of  which  by  th9 
hammer  formerly  cost  from  five  to  ten 
pounds  sterling  the  running  yard,  in 
Germany,  is  executed  at  the  present  day 
by  gunpowder  at  from  two  to  three 
pounds.  When,  however,  a  precious 
mass  of  ore  is  to  be  detached,  wnen  the 
rock  is  cavernous,  which  nearly  nullifies 
the  action  of  gunpowder,  or  when  there 
is  reason  to  apprehend  that  the  shock 
caused  by  the  explosion  may  produce  an 
injurious  fall  of  rubbish,  hand-tools 
alone  must  be  employed. 

When  the  rocks  which  cover  valuable 
minerals  are  not  of  very  great  hardness, 
as  happens  generally  with  the  coal  forma- 
tion, with  pyritous  and  aluminous  slates, 
sal  gem,  and  some  other  minerals  of  the 
secondary  strata,  the  borer  is  employed 


374 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mth 


with  advantage  to  ascertain  their  nature. 
This  mode  of  investigation  is  economical, 
and  gives,  in  such  cases,  a  tolerably  exact 
insight  into  the  riches  of  the  interior. 

The  mode  of  working  mines  is  two- 
fold ;  by  open  excavations,  and  subter- 
ranean. 

Workings  in  the  open  air  present  few 
difficulties,  and  occasion  little  expense, 
unless  when  pushed  to  a  great  depth. 
They  are  always  preferred  tor  working 
deposits  little  distant  from  the  surface; 
where,  in  fact,  other  methods  cannot  be 
resorted  to,  if  the  substance  to  be  raised 
be  covered  with  incoherent  matters.  The 
only  rules  to  be  observed  are,  to  arrange 
the  workings  in  terraces,  so  as  to  facili- 
tate the  cutting  down  of  the  earth ;  to 
transport  the  ores  and  the  rubbish  to 
their  destination  at  the  least  possible  ex- 
pense, and  to  guard  against  the  crumb- 
ling down  of  the  sides.  With  the  latter 
view,  they  ought  to  have  a  suitable  slope ; 
or  to  be  propped  by  timbers  whenever 
they  are  not  quite  solid. 

Open  workings  are  employed  for  valu- 
able clays,  sands,  as  also  for  the  alluvial 
soils  of  diamonds,  gold,  and  oxide  of  tin, 
bos:  iron  ores,  &c,  limestones,  gypsums, 
building  stones,  roofing  slates,  masses  of 
rock-salt  in  some  situations,  and  certain 
deposits  of  ores,  particularly  the  specu- 
lar iron  of  the  island  of  Elba,  the  masses 
of  stanniferous  granite  of  Gayer,  Alten- 
berg,  and  Seyfen,  in  the  Ertzgeberge,  a 
chain  of  mountal  is  between  Saxony  and 
Bohemia  ;  the  thic»c  veins  or  masses  of 
black  oxide  of  iron  of  Nordmarch,  Dan- 
nemora,  &c,  in  Sweden;  the  mass  of 
cupreous  pyrites  of  Baeraas,  near  Dron- 
theim  in  Norway;  several  mines  of  iron, 
copper,  and  gold  in  the  Ural  mountains, 
&c. 

Subterranean  workings  may  be  con- 
veniently divided  into  five  classes,  viz. : — 

1.  Veins  or  beds,  much  inclined  to  the 
horizon,  having  a  thickness  of  at  least 
two  yards. 

2.  Beds  of  slight  inclination,  or  nearly 
horizontal,  the  power  or  thickness  of 
which  does  not  exceed  two  yards. 

3.  Beds  of  great  thickness,  but  slight- 
ly inclined. 

4.  Veins,  or  beds  highly  inclined,  of 
great  thickness. 

5.  Masses  of  considerable  magnitude  in 
all  their  dimensions. 

Subterranean  mining  requires  two  very 
distinct  classes  of  workings ;  the  prepara- 
tory, and  those  for  extraction. 

The  preparatory  consist  in  galleries,  or 
m  pits  and  galleries  destined  to  conduct 


the  miner  to  the  point  most  proper  for 
attacking  the  deposit  of  ore,  lor  tracing 
it  all  round  this  point,  for  preparing 
chambers  of  excavation,  and  for  concert- 
ing measures  with  a  view  to  the  circula- 
tion of  air,  the  discharge  of  waters,  and 
the  transport  of  the  extracted  minerals. 

If  the  vein  or  bed  in  question  be  placed 
in  a  mountain,  and  if  its  direction  forms 
a  very  obtuse  angle  with  the  line  of  the 
slope,  the  miner  begins  by  opening  in  its 
side,  at  the  lowest  possible  level,  a  gallery 
of  elongation,  which  serves  at  once  to 
give  issue  to  the  waters,  to  explore  the 
deposit  through  a  considerhtjjeextent, 
and  then  to  follow  it  in  another  direction ; 
but  to  commence  the  real  mining  opera- 
tions, he  pierces  either  shaftsorgalleries, 
according  to  the  slope  o^fhe  deposit, 
across  the  first  gallery.  n. 

For  a  stratum  little  inclined  to  the 
horizon,  placed  beneath  a  pkun,  the  first 
thing  is  to  pierce  two  vertical  shafts, 
which  are  usually  made  to(  arrive  at  two 
points  in  the  same  line  of  slope,  and  a 
gallery  is  driven  to  unite  tntem.  It  is,  in 
the  first  place,  for  the  sake  of  circulation 
of  air  that  these  two  pits  are  sunk;  one 
of  them,  which  is  also  destinec 
drainage  of  the  waters,  should  reach  the 
lowest  point  of  the  intended  workings. 

The  excavations  of  mines  are  divisible 
into  three  principal  species  ;  shafts,  gal- 
leries, and  chambers.  When  the  width  of 
these  excavations  is  inconsiderable,  as  is 
commonly  the  case  with  shafts  and  gal- 
leries, their  sides  can  sometimes  stand 
upright  of  themselves  •  but  more  fre- 
quently they  require  to^be  propped  or 
stayed  by  billets  of  wood,  or  by  walls 
built  with  bricks  or  stones ;  or  even  by 
stuffing:  the  space  with  rubbish.  These 
three  kinds  of  sujrport  are  called  timber- 
ing, waiting,  and  filling  up. 

Timbering  is  most  used.  It  varies  in 
form  for  the  three  species  of  excavations, 
according  to  the  solidity  of  the  walls 
which  it  is  destined  to  sustain. 

The  timbering  of  shafts  varies  in  form, 
as  well  as  that  of  galleries,  according  to 
the  nature  and  the  locality  of  the  ground 
which  they  traverse,  and  the  purposes 
which  they  are  meant  to  serve.  The 
shafts  intended  to  be  stayed  with  timber 
are  usually  square  or  rectangular,  because 
this  form",  in  itself  more  convenient  for 
the  miner,  renders  the  execution  of  the 
timbering  more  easy.  The  wood-work 
consists  generally  of  rectangular  frames, 
the  spars  of  which  are  about  eight  incbe* 
in  diameter,  and  placed  at  a  distance 
asunder  of  from  a  yard  to  a  yard  and  a 


min] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


375 


half.  The  spars  are  never  placed  in  con- 
tact, except  when  the  pressure  of  the 
earth  and  the  waters  is  very  great.  The 
pieces  composing  the  frames  are  com- 
monly united  by  a  half- check,  and  the 
longer  of  the  two  pieces  extends  often 
beyond  the  angles,  to  be  rested  in  the 
rock.  Whether  the  shaft  is  vertical  or 
inclined,  the  frame-work  is  always  placed 
so  that  its  plane  may  be  perpendicular  to 
the  axis  of  the  pit.  It  happens  some- 
times in  i  nclined  shafts  that  there  are 
only  two  sides,  or  even  a  single  one, 
which  needs  to  be  propped.  These  are 
stayed  by  means  of  cross  beams,  which 
rest  at  their  two  ends  in  the  rock.  When 
the  frames  do  not  touch  one  another, 
strong  planks  or  stakes  are  fastened  be- 
hind "them  to  sustain  the  ground.  To 
these  planks  the  frames  are  firmly  con- 
nected, so  that  they  cannot  slide.  In  this 
case  the  whole  timbering  will  be  sup- 
ported, when  the  lower  frame  is  solidly 
fixed,  or  when  the  pieces  from  above 
pass  bv  its  angles  to  be  abutted  upon  the 
ground. 

In  the  large  rectangular  shafts,  which 
serve  at  once  for  extracting  the  ores,  for 
the  discharge  of  the  waters,  and  the  de- 
scent of  the  workmen,  the  spaces  destined 
for  these  several  purposes  are  in  general 
separated  by  partitions,  which  also  serve 
to  increase  the  strength  of  the  timber- 
ings, by  acting  as  buttresses  to  the  planks 
in  the  long  sides  of  the  frame-work.  -» 

When  men  penetrate  by  narrow  pas- 
sages into  the  interior  of  tlie  earth,  their 
respiration,  joined  to  the  combustion  of 
candle  and  gunpowder,  are  not  long  in 
vitiating  the  air.  The  decomposition  of 
wood  contributes  to  the  same  effect,  as 
also  the  mineral  bed  itself,  especially  in 
coal  mines,  by  the  carburetted  hydrogen 
and  carbonic  acid  evolved,  and  from  the 
absorption  of  oxygen  by  pyrites.  In 
many  cases,  arsenical  and  mercurial  va- 
pors are  disengaged.  Hence  the  necessity 
of  maintaining  in  subterranean  cavities  a 
continual  circulation  of  air,  which  may 
renew  the  atmosphere  round  the  miners. 
The  whole  of  the  means  employed  to 
produce  this  effect,  constitutes  what  is 
called  the  ventilation  of  mines. 

These  means  are  divided  into  natural 
and  artificial.  The  natural  means  are 
the  currents  produced  by  the  difference 
of  density  between  the  air  of  mines  and 
the  external  air;  the  artificial  are  air- 
exhausters  or  condensers,  fires,  &c. 

The  temperature  of  the  air  of  the  sub- 
terranean workings  surpasses  the  mean 
temperature  of  the  place  in  which  the 


mine  is  opened.  Hence  it  is  lighter  in 
winter,  but  in  summer  often  heavier  than 
the  air  of  the  atmosphere.  For  this  rea- 
son, when  the  mine  presents  two  open- 
ings at  different  levels,  the  air  naturally 
flows  out  by  the  most  elevated  in  winter, 
and  by  the'lowest  in  summer.  We  may 
take  advantage  of  this  circumstance,  to 
lead  the  air  into  the  bottom  of  even  a 
very  long  gallery,  opening  into  the  side 
of  the  mountain,  bv  piercing  a  shaft  into 
its  roof  at  some  distance  from  the  en- 
trance, and  dividing  the  gallery  by  a 
horizontal  floor  into  two  parts,  which 
have  no  mutual  communication,  except 
at  the  furthest  extremity— the  upper  part 
communicating  with  the  shaft,  and  the 
under  with  the  mouth  of  the  gallery.  If 
the  two  compartments  have  different  di- 
mensions, the  air  in  the  smaller  sooner 
comes  into  an  equilibrium  of  temperature 
with  the  rock  ;  and  the  difference  of  tem- 
perature of  the  two  compartments  is  suf- 
ficient to  produce  a  current.  If  a  stream- 
let of  water  flows  through  this  gallery,  it 
facilitates  the  flow  of  the  air  along  the 
lower  compartment.  If  a  mine  has  several 
openings  situated  on  the  same  level,  it 
rarely  happens  but  some  peculiar  circum- 
stance destroys,  during  the  colds  of  win- 
ter and  the  heats  of  summer,  the  equili- 
brium of  the  air.  But  in  spring  and 
autumn,  when  the  external  air  is  nearly 
of  the  same  temperature  with  that  of  the 
mines,  the  above-named  causes  are  al- 
most always  too  feeble  to  excite  an  issu- 
ing current.  The  effect  is,  however,  fre- 
quently obtained  by  raising  over  one  of 
the  shafts  a  chimney  20  or  30  yards  high, 
which  alone  produces  the  effect  of  an 
opening  at  a  different  level.  It  has  been 
remarked  that  stormy  weather  usually 
deranges  every  system  of  ventilation. 

The  chain  of  the  Alleganies,  which  tra- 
verses the  United  States  of  North  Ame- 
rica from  N.W.  to  S.E.,  includes  a  con- 
siderable number  of  deposits  of  iron, 
lead,  and  copper  ores ;  along  with  some 
ores  of  silver,  plumbago,  and  chromite  of 
iron.  Attempts  have  been  made  to  mine 
a  great  many  of  these  deposits,  but  most 
of  these  have  been  unsuccessful,  and 
abandoned  for  a  while.  Some  have  been 
since  re-opened. 

A  bed  of  black  oxyde  of  iron  occurs  in 
gneiss  near  Franconia  in  New  Hamp- 
shire. It  has  a  power  of  from  5  to  8  feet ; 
and  han  been  mined  through  a  length  of 
200  feet,  and  to  a  depth  of  90  feet.  The 
same  ore  is  found  in  veins  in  Massachu- 
setts and  Vermont,  accompanied  by  cop- 
per and  iron  pyrites.    It  is  met  with  in 


376 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[min 


immense  quantities  on  the  western  bank 
of  the  lake  Champlain,  forming  beds  of 
from  1  to  20  feet  in  thickness,  almost 
■without  mixture,  encased  in  granite.  It 
is  also  found  in  the  mountains  of  that 
territory.  These  deposits  appear  to  ex- 
tend without  interruption  from  Canada 
to  the  neighborhood  of  New- York,  where 
an  exploration  on  them  may  bo  seen  at 
Crown  Point.  The  ore  there  extracted 
is  in  much  esteem.  Several  mines  of  the 
same  species  exist  in  New  Jersey.  The 
primitive  mountains  which  rise  in  the 
north  of  this  state  near  the  Delaware,  in- 
clude a  bed  almost  vertical  of  black  oxide 
of  iron,  which  has  been  worked  to  100 
feet  in  depth.  In  the  county  of  Sussex 
the  same  ore  occurs,  accompanied  with 
Franklinite.  At  New  Milford,  in  Con- 
necticut, a  pretty  abundant  mine  of 
sparry  iron  occurs  ;  the  only  one  of  the 
kind  known  in  the  Alleganies.  The 
United  States  contain  a  great  many  iron 
works,  some  of  which  prior  to  the  year 
1773,  sent  over  iron  to  London.  They 
are  principally  supplied  from  alluvial  iron 
ore.  Under  the  article  Iron,  various  lo- 
calities of  the  ores  have  been  cited. 

The  most  remarkable  lead  mines  of  the 
Alleganies  are  those  of  Southampton,  in 
Massachusetts,  and  of  Perkiomen  creek, 
in  Pennsylvania,  8  leagues  from  Phila- 
delphia. The  first  furnishes  a  galena, 
slightly  argentiferous ;  an  ore  accompa- 
nied with  various  minerals,  with  base  of 
lead,  copper,  and  zinc,  and  with  gangues 
(vein-stones)  of  quartz,  sulphate  of  bary- 
ta, and  fluor  spar.  These  substances 
form  a  vein  which  traverses  several  pri- 
mitive rocks,  and  is  said  to  be  known 
over  a  length  of  more  than  6  leagues. 
At  Perkiomen  creek  a  vein  of  galena  is 
mined  which  traverses  a  sandstone,  re- 
ferred by  many  geologists  to  the  old  red 
sandstone.  Along  with  galena  a  great 
variety  of  minerals  is  found  with  a  basis 
of  lead,  zinc,  copper,  and  iron.  The 
mines  of  lead  worked  in  Virginia,  on  the 
banks  of  the  Kanahwa,  deserve  also  to  be 
mentioned.  Under  the  articles  Galena  and 
Lead  notice  has  been  made  of  the  other 
deposits  of  lead  in  the  United  States. 

None  of  the  copper  mines  actually  in 
operation  in  the  United  States  seem  to 
merit  particular  attention.  The  mine  of 
Schuyler,  in  New  Jersey,  had  excited 
high  hopes,  but  after  the  workings  had 
been  pushed  to  a  depth  of  300  feet,  they 
have  been  for  some  years  abandoned. 
The  ore,  which  consisted  of  sulphuret  of 
copper,  with  oxide  and  carbonate  of  cop- 
per, occurred  in  a  red  sandstone.   No  re- 


ference is  made  here  to  the  extensive 
native  copper  deposits  of  Lake  Superior. 

In  some  points  of  the  Alleganies,  de- 
posits have  been  noticed  of  chromite  of 
iron  and  graphite. — See  Chrome. 

Coal-measures  occur  in  several  points 
of  the  United  States,  especially  on  the 
N.W.  slope  of  the  Allegany  mountains, 
in  Michigan,  Ohio,  and  Missouri. 

MINERALS  comprehend  all  the  solid 
matters  of  the  earth,  not  vegetable  or 
animal ;  for,  though  these  last  are  in 
substance  mineral,  yet  their  organization 
and  phenomena  separate  them  from  the 
simple  mineral.  In  like  manner,  though 
the  gases  and  acids  may  be  generated  from 
minerals,  and,  again  perhaps  concentra- 
ted into  minerals,  yet  they  are  not  in  a 
just  sense  to  be  regarded  as  minerals. 

The  system  of  Mohs  includes  these  as 
two  genera,  and  adds  a  third  in  water. 
Logic  thus  confounds  nature.  As  a  sum- 
mary, we  will  subjoin  his  orders  strictly 
mineral,  as  a  brief  exhibition  of  similar 
substances. 

Salt  Order. — Genera.  1.  Natron.  2. 
Glauber.  3.  Nitre.  4.  Rock.  5.  Am- 
moniac. 6.  Vitriol.  7.  Epsom.  8.  Alum. 
9.  Borax.    10.  Brythine. 

Haloide  Order. — Genera.  1.  Gypsum 
2.  Cryone.     3.  Alum.   4.  Fluor.    5.  Calc. 

Baryte  Order. — Genera.  1.  Para- 
ehrose.   2.  Zinc.    3.   Scheelium.    4.  Hal. 

5.  Lead. 

Malachite  Order. — Genera.  1.  Sta- 
phyline.  2.  Lirocone.  3.  Olive.  4. 
Azure.    5.  Emerald.    6.  Habroneme. 

Mica  Order. — Genera.  1.  Euchlore. 
2.  Cobalt.  3.  Iron.  4.  Graphite.  5.  Talc. 

6.  Pearl. 

Spar  Order. — Genera.  1.  Schiller.  2. 
Disthene.  3.  Triphane.  4.  Dystome.  5. 
Kouphone.     6.   Petaline.      7.   Feldspar. 

8.  Augite.    9.  Azure. 

Gem  Order. — Genera.  1.  Andalusite. 
2.  Corundum.     3.  Diamond.     4.  Topaz. 

5.  Emerald.  6.  Quartz.  7.  Aximite.  8. 
Chrysolite.  9.  Boracite.  10.  Tourma- 
line. 11.  Garnet.  12.  Zircon.  13.  Ga- 
dolinite. 

Ore  Order. — Genera.  1.  Titanium.  2. 
Zinc.    3.  Copper.    4.  Tin.    5.  Scheelium. 

6.  Tantalum.     7.  Uranium.    8.  Cerium. 

9.  Chrome.    10.  Iron.    11.  Manganese. 
Metal  Order. — Genera.   1.  Arsenic.    2. 

Tellurium.  3.  Antimony.  4.  Bismuth. 
5.  Mercury.  6.  Silver.  7.  Gold.  8.  Pla- 
tina.     9.  Iron.    10.  Copper. 

Pyrites  Order. — Genera.  1.  Nickel.  2. 
Arsenic.    3.  Cobalt.  4.  Iron.  5.  Copper. 

Glance  Order. — Genera.  1.  Copper. 
2.  Silver.     8.  Lead.     4.   Tellerium.     5. 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


377 


Molybdenum.  6.  Bismuth.  7.  Antimo- 
ny.   8.  Melane. 

Blende  Order. — Genera.  1.  Glance.  2. 
Garnet.    3.  Purple.    4.  Ruby. 

He  then  makes  sulphur,  resin,  and 
mineral  coal  separate  orders. 

Hardness  in  minerals  is  expressed  by 
the  figures  1  to  10,  with  the  letter  H. 


1  is 

as   Talc. 

2      . 

Gypsum. 

3      . 

Calcareous  Spar. 

4      . 

Fluor  Spar. 

5  . 

6  . 

Apatite. 
Feldspar. 

7      . 

Quartz. 

8 

.      Topaz. 

9 

Corundun. 

10      . 

Diamond. 

The  study  of  mineralogy  has  made  great 
progress  in  this  country  within  the  last 
thirty  years  :  almost  all  the  known  spe- 
cies have  been  found  and  described  on 
this  continent,  and  several  new  species 
have  been  added  to  the  list.  The  most  ap- 
proved work  on  this  science  with  its  refer- 
ence to  this  continent,  is  that  of  Mr.Dana. 
Mineral  Waters,  are  those  waters 
which  contain  such  a  proportion  of  for- 
eign matter  as  to  render  them  unfit  for 
common  use,  and  give  them  a  sensible 
flavor  and  a  specific  action  upon  the  ani- 
mal economy.  They  are  commonly  divi- 
ded into  four  classes  :  acidulous  or  car- 
bonated, saline,  chalybeate  or  ferrugin- 
ous, and  sulphureous.  In  regard  to  tem- 
perature they  are  divided  into  warm  and 
cold.  The  substances  found  in  mineral 
waters  are  numerous  :  the  most  frequent 
being  nitrogen,  oxygen,  sulphur,  ana  car- 
bon, lime,  iron,  and  magnesia.  Artificial 
waters  are  now  made  to  represent  the 
natural  springs,  and  are  equally  efficacious 
as  medical  agents  :  so  that  there  are 
natural  and  artificial  mineral  waters.  The 
saline  springs  are  composed  of  salts  of 
soda  and  lime,  or  occasionally  magnesia 
replacing  the  soda  with  excess  of  carbonic 
acid,  and  oxide  of  iron.  The  chief  are 
those  of  Pyrmont,  Seidlitz,  and  Epsom. 
The  ferruginous  waters  have  a  styptic 
taste,  and  are  turned  black  by  infusion  of 
nut-galls  ;  sometimes  the  iron  exists  in 
the  water  as  an  oxide  dissolved  by  car- 
bonic acid,  sometimes  as  a  sulphate,  and 
sometimes  in  both  conditions  together. 
Such  are  the  waters  of  Vichy,  Forges, 
Passy,  Spa,  Cheltenham,  and  Tun- 
bridge  :  Bedford,  Pittsburgh,  Yellow 
Springs  in  Ohio,  Virginia,  and  Pennsyl- 
vania belong  also  to  this  class.  Acidu- 
lous waters  have  an  acid  taste  and  extri- 
cate carbonic  acid,  of  which  they  contain 


five  or  six  times  their  volume.  They 
contain  carbonates  and  chlorides  of  mag- 
nesia and  lime,  carbonate  and  sulphate  of 
iron  ;  such  are  the  waters  of  Bath,  Bux- 
ton, Bristol,  Vichy,  Seltzer,  New  Leba- 
non, &c.  They  are  acidulous.  The  sul- 
phuretted waters  are  easily  known  by 
their  smell  and  their  tarnishing  silver  and 
copper  :  such  are  those  of  Harrowgate, 
Moffat,  Aix  la  Chapelle,  Saratoga  and 
Ballston. 

MINIUM.  This  pigment  is  a  peculiar 
oxyde  of  lead,  consisting  of  two  atoms  of 
the  protoxyde  and  one  of  the  peroxyde  ; 
but,  as  found  in  commerce,  it  always  con- 
tains a  little  extra  protoxyde,  or  yellow 
massicot.  It  is  prepared'  by  calcining 
lead  upon  a  reverberatory  hearth  with  a 
slow  fire,  and  frequent  renewal  of  the 
surface  with  a  rake,  till  it  becomes  an  ox- 
yde, taking  care  not  to  fuse  it.  The  cal- 
cined mass  is  triturated  into  a  fine  pow- 
der in  a  paint  mill,  where  it  is  elutri- 
ated with  a  stream  of  water,  to  carry  off 
the  finely  levigated  particles,  and  to  de- 
posit them  afterwards  in  tanks.  The 
powder  thus  obtained,  being  dried,  is 
called  massicot.  It  is  converted  into 
minium,  by  being  put  in  quantities  of 
about  50  pounds  into  iron  trays,  1  foot 
square,  and  4  or  5  inches  deep.  These 
are  piled  up  upon  the  reverberatory 
hearth,  and  exposed  during  the  night, 
for  economy  of  fuel,  to  the  residuary  heat 
of  the  furnace,  whereby  the  massicot  ab- 
sorbs more  oxygen,  and  becomes  par- 
tially red  lead.  This,  after  being  stirred 
about,  and  subjected  to  a  similar  low  cal- 
cining heat  once  and  again,  will  be  found 
to  form  a  marketable  red  lead. 

The  best  minium,  however,  called  or- 
ange mine,  is  made  by  the  slow  calcina- 
tion of  good  white  lead  (carbonate)  in 
iron  trays.  If  the  lead  contains  either 
iron  or  copper,  it  affords  a  minium  which 
cannot  be  employed  with  advantage  in 
the  manufacture  of  flint-glass  for  pottery 
glazes,  or  for  house-painting. 

Dumas  found  several  samples  of  red 
lead  which  he  examined  to  consist  of  tho 
chemical  sesquioxyde,  and  the  protoxyde, 
in  proportions  varying  from  50  of  the  for-' 
mer  and  50  of  the  latter,  to  95-3  of  the 
former  and  4*7  of  the  latter.  The  more 
oxygen  gas  it  gives  out  when  heated,  the 
better  it  is,  generally  speaking. 

MIEEOE.  A  speculum  or  looking- 
glass,  or  any  other  polished  body  capable 
of  reflecting  the  images  of  objects,  raya 
of  light  from  which  fall  upon  them.  Sil- 
ver is  considered  to  be  the  most  power- 
ful reflector;  but  the  speculum  metal,  as 


378 


CYCLOPEDIA    OP   THE   USEFUL   ARTS. 


[mor 


now  prepared,  is  scarcely  inferior,  if  at 
all  so,  and  in  some  cases  even  better.  In 
the  very  early  ages  of  the  world,  polished 
metallic  specula  wore  employed  as  mir- 
rors by  the  Jewish  and  Egyptian  women, 
especially  of  brass  :  but  in  modern  times, 
quicksilver  piates  of  glass  are  alone  used 
as  mirrors. 

Concave  Mirrors  are  used  to  concentrate 
the  rays  of  the  sun  in  a  single  point,  and 
thereby  produce  intense  heat.  The  sur- 
faces formed  by  the  revolution  of  the 
ellipse,  parabola,  and  hyperbola,  are  such 
as  reflect  them  accurately  to  one  point ; 
provided  they  emanate  from  one  point, 
are  parallel  to  one  another  (as  the  solar 
rays),  or  would  converge  to  a  more  re- 
mote point  than  it  is  desirable  to  use. 
The  great  difficulty  of  constructing  these 
has  led  to  the  employment  of  spherical 
segments,  which,  though  not  accurate, 
yet,  under  proper  restrictions,  are  ap- 
proximately so. 

MISP1CKEL.    Arsenical  pyrites. 

MODEL,  in  sculpture,  figures  made 
in  wax,  terra  cotta,  or  other  plastic  mate- 
rial, which  the  artist  moulds  to  guide 
him  in  his  work ;  in  the  same  way  as  the 
painter  makes  a  sketch,  or  the  artist  a 
design.  When  a  model  of  any  object  is 
to  be  taken,  the  object  should  first  be 
greased  so  as  to  prevent  the  plaster  from 
sticking  to  it,  and  then  be  placed  on  a 
smooth  table  previously  oiled  or  covered 
with  cloth ;  the  original  is  then  sur- 
rounded with  a  frame  or  raised  margin 
of  putty  or  card  at  such  a  distance  as  to 
allow  of  the  plaster  resting  on  the  table 
on  every  side  of  the  subject,  as  wide  as 
may  be  thought  necessary  for  the 
strength  of  the  object.  The  plaster  is 
then  poured  on  as  uniformly  as  possible 
over  the  whole  substance,  until  it  is 
every  where  covered  to  desirable  thick- 
ness. It  is  then  allowed  to  settle  till  the 
plaster  has  become  cool  and  hardened; 
the  frame  is  then  removed  and  the  mould 
inverted,  and  subject  taken  out  of  it: 
when  the  plaster  is  thoroughly  dry  it 
should  be  seasoned. 

MOHAIR.  The  hair  of  a  variety  of 
the  common  goat,  famous  for  being  soft 
and  fine  as  silk,  and  of  a  silvery  white- 
ness. It  is  not  produced  anywhere  but 
in  the  vicinity  of  Angora,  in  Asia  Minor. 
The  exportation  of  this  valuable  and 
beautiful  article,  unless  in  the  shape  of 
yarn,  was  formerly  prohibited ;  but  it 
may  now  be  exported  unspun.  The  pro- 
duction, preparation,  and  sale  of  mohair 
have  Ion?  engrossed  the  principal  atten- 
tion of  the  inhabitants  of  Angora;  and  it 


used  to  form  an  important  article  of  Ve- 
netian commerce.  It  is  manufactured 
into  camlets  and  other  expensive  stuffs. 
Hitherto  but  little  has  been  imported  into 
England  or  this  country. 

MOIREE  METALLIQUE,  called  also 
crystalline  tin  plate,  is  a  primrose  appear- 
ance, produced  upon  the  surface  of  tin 
plate  by  exposing  it  to  the  vapor  of,  or 
washing  it  over  with,  dilute  mtromuria- 
tic  acid,  rinsing  with  water,  and  then 
covering  with  lacker.  The  plate  treated 
in  this  way  has  a  beautiful  and  variegated 
appearance. 

MONOCHROMATIC  LAMP.  When 
a  solution  of  common  salt  is  added  to 
spirit  of  wine,  the  mixture  burns  with  a 
flame  in  which  yellow  predominates  al- 
most to  the  exclusion  of  the  other  colored 
rays ;  the  consequence  is,  that  objects 
viewed  by  this  light  are  all  either  yellow 
or  black,  and  deficient  in  the  tints  which 
they  exhibit  when  seen  by  solar  light,  or 
by  that  of  our  ordinary  combustibles. 

MOLYBDENUM,  is  a  rare  metal, 
which  occurs  in  nature  sometimes  as  a 
sulphuret,  sometimes  as  molybdic  acid, 
and  at  others  as  molybdate  of  lead.  Its 
reduction  from  the  acid  state  by  charcoal 
requires  a  very  high  heat,  and  affords 
not  very  satisfactory  results.  When  re- 
duced by  passing  hydrogen  over  the  ig- 
nited acid,  it  appears  as  an  ash-gray 
powder,  susceptible  of  acquiring  metallic 
lustre  by  being  rubbed  with  a  steel  bur- 
nisher ;  when  reduced  and  fused  with 
charcoal,  it  possesses  a  silver  white  color, 
is  very  brilliant,  hard,  brittle,  of  specific 
gravity  8*6 ;  it  melts  in  a  powerful  air- 
furnace,  oxydizes  with  heat  and  air,  burns 
at  an  intense  heat  into  molybdic  acid, 
dissolves  in  neither  dilute  sulphuric, 
muriatic,  nor  fluoric  acids,  but  in  the  con- 
centrated sulphuric  and  nitric. 

The  protoxyde  consists  of  85-69  of  me- 
tal, and  14-31  of  oxygen ;  the  deutoxyde 
consists  of  75  of  metal,  and  25  of  oxy- 
gen ;  and  the  peroxyde,  or  molybdic  acid, 
of  66-6  of  metal,  and  38-4  of  oxygen. 
These  substances  are  too  rare  at  present 
to  be  used  in  any  manufacture. 

Molybdic  acid  when  united  with  ammo- 
nia, forming  the  molybdate  of  ammonia, 
is  now  employed  as  the  most  delicate 
chemical  test  for  the  presence  of  phos- 
phoric acid.  It  is  the  most  delicate  means 
of  detecting  the  presence  of  the  latter 
substance. 

MORDANT,  in  dying  and  calico-print- 
ing, denotes  a  body  which,  having  a  two- 
fold attraction  for  organic  fibres  and 
coloring  particles,  serves  as  a  bond  of 


MOR^ 


CYCLOPEDIA    OP   THE    USEFUL   ARTS. 


nnion  between    them,   and    thus  gives 
fixity  to  dyes ;  or  it  signifies  a  substance 
which,  by  combining  with  coloring  par- 
ticles in  the  pores  of  textile  filaments, 
renders  them  insoluble  in  hot  soapy  and 
weak  alkaline  solutions.     In  order  pro- 
perly to  appreciate  the  utility  and  the 
true  functions  of  mordants,  we  must  bear 
in  mind  that  coloring  matters  are  peculiar 
compounds  possessed  of  certain  affinities, 
their  distinctive  characters  being  not  to 
be  either  acid  or  alkaline,  and  yet  to  be 
capable  of  combining  with  many  bodies, 
and  especially  with  salifiable  bases,  and 
of  receiving  from  each  of  them  modifica- 
tions in  their  color,  solubility,  and  alter- 
ability.      Organic    coloring    substances, 
when  pure,  have  a  very  energetic  attrac- 
tion for  certain  bodies,  feeble  for  others, 
and  none  at  all  for  some.    Among  these 
immediate  products  of  animal  or  vegeta- 
ble life,  some  are  soluble  in  pure  water, 
and  others  become  so  only  through  pecu- 
liar agents.     We  may  thus  readily  con- 
ceive, that  whenever  a  dye-stuff  possesses 
a  certain  affinity  for  the  organic  fibre,  it 
will  be  able  to  become  fixed  on  it,  or  to 
dye  it  without  the  intervention  of  mor- 
dants, if  it  be  insoluble  by  itself  in  water, 
which,  in  fact,  is  the  case  with  the  color- 
ing matters  of  safflower,  annotto,  and  in- 
digo.   The  first  two  are  soluble  in  alkalis  • 
hence,  in  order  to  use  them,  they  need 
only  be  dissolved  in  a  weak  alkaline  ley, 
be  thus  applied  to  the  stuffs,  and  then 
have  their  tinctorial  substance  precipi- 
tated within  their  pores,  by  abstracting 
their  solvent  alkali  with  an  acid.    The 
coloring  matter,  at  the  instant  of  ceasing 
to  be  liquid,  is  in  an  extremely  divided 
state,  and  is  in  contact  with  the  organic 
fibres  for  which  it  has  a  certain  affinity. 
It  therefore  unites  with  them,  and,  being 
naturally  insoluble  in  water,  that  is,  hav- 
ing no  affinity  for  this  vehicle,  the  subse- 
3uent  washings  have  no  effect  upon  the 
ye.    The  same  thing  may  be  said  of  in- 
digo, although  its  solubility  in  the  dye- 
bath  does  not  depend  upon  a  similar 
cause,  but  is  due  to  a  modification  of  its 
constituent  elements,  in  consequence  of 
which    it    becomes    soluble    in    alkalis. 
Stuffs  plunged  into  this  indigo  bath  get 
impregnated  with  the  solution,  so  that 
when  again  exposed  to  the  air,  the  dye- 
ing substance  resumes  at  once  its  primi- 
tive color  and  insolubility,  and  washing 
can  carry  off  only  the  portions  in  excess 
above  the  intimate  combination,  or  which 
are  merely  deposited  upon  the  surface  of 
the  stuff.  * 

Such  is  the  result  with  insoluble  color- 


ing matters :  but  for  those  which  are  so- 
luble it  should  be  quite  the  reverse,  since 
they  do  not  possess  an  affinity  for  the  or- 
ganic fibres,  which  can  counterbalance 
their  affinity  for  water.  In  such  circum- 
stances, the  dyer  must  have  recourse  to 
intermediate  'bodies,  which  add  their 
affinity  for  the  coloring  matter  to  that 
possessed  by  the  particles  of  the  stuff, 
and  increase  by  this  two-fold  action  the 
intimacy  and  the  stability  of  the  combi- 
nation. These  intermediate  bodies  are 
the  true  mordants. 

Mordants  are  in  general  found  among 
the  metallic  bases  or  oxydes ;  whence 
they  might  be  supposed  to  be  very  nu- 
merous, like  the  metals ;  but  as  they 
must  unite  the  two-fold  condition  of  pos- 
sessing a  strong  affinity  for  both  the 
coloring  matter  and  the  organic  fibre, 
and  as  the  insoluble  bases  are  almost  the 
only  ones  fit  to  form  insoluble  combina- 
tions, we  may  thus  perceive  that  their 
number  may  bo  very  limited.  It  is  well 
known,  that  although  lime  and  magnesia, 
for  example,  have  a  considerable  affinity 
for  coloring  particles,  and  form  insoluble 
compounds  with  them,  yet  they  cannot 
be  employed  as  mordants,  because  they 
possess  no  affinity  for  the  textile  fibres. 

Experience  has  proved,  that  of  all  the 
bases,  those  which  succeed  best  as  mor- 
dants are  alumina,  tin,  and  oxyde  of  iron ; 
the  first  two  of  which,  being  naturally 
white,  are  the  only  ones  which  can  be 
employed  for  preserving  to  the  color  its 
original  tint,  at  least  without  much  va- 
riation. But,  whenever  the  mordant  is 
itself  colored,  it  will  cause  the  dye  to  take 
a  compound  color  quite  different  from  its 
own.  If,  as  is  usually  said,  the  mordant 
enters  into  a  real  chemical  union  with  the 
stuff  to  be  dyed,  the  application  of  the 
mordant  should  obviously  be  made  in 
such  circumstances  as  are  known  to  be 
most  favorable  to  the  combination  taking 

§lace  ;  and  this  is  the  principle  of  every 
ay's  practice  in  the  dye-house. 
Mordant  is  also  the  name  sometimes 
given  to  the  adhesive  matter  by  which 
gold-leaf  is  made  to  adhere  to  surfaces  of 
wood  and  metal  in  gilding.  Paper, 
vellum,  taffety,  &c,  are  easily  gilt  by  the 
aid  of  different  mordants,  such  as  the 
following:  1,  beer  in  which  some  honey 
and  gum  arabic  have  been  dissolved  :  2, 
gum  arabic,  sugar,  and  water;  3,  the 
viscid  juice  of  onion  or  hyacinth,  strength- 
ened with  a  little  gum  arabic.  When 
too  much  gum  is  employed,  the  silver  or 
gold  is  apt  to  crack  in  the  drying  of  the 
mordant.      A  little  carmine  should   be 


38C 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


(MOR 


mixe^.  with  the  above  colorless  liquids, 
to  mark  the  places  where  they  are  ap- 
plied. The  foil  is  applied  by  means  of  a 
dossil  of  cotton  wool,  and  when  the  mor- 
dant has  become  hard,  the  foil  is  polished 
with  the  same. 

The  best  medium  for  sticking  gold  and 
silver  leaf  to  wood  is  the  following,  called 
mixtion  by  the  French  artists  : — 1  pound 
of  amber  is  to  be  fused,  with  4  ounces  of 
mastic  in  tears,  and  1  ounce  of  Jewish 
pitch,  and  the  whole  dissolved  in  1  pound 
of  linseed  oil  rendered  drying  by  litharge. 

The  above  is  used  by  distemper  paint- 
ers and  paper-hanging  manufacturers  for 
attaching  gold  and  silver  leaf  to  walls  or 
paper. 

MORPHIA.  To  obtain  this  substance 
from  opium,  free  from  narcotine  : — Eva- 
porate to  the  consistence  of  an  extract  a 
spiritous  solution  of  opium ;  then,  by 
successive  solutions  and  nitrations,  sepa- 
rate all  the  resinous  matter  of  the  extract, 
which  separates  the  narcotine  from  the 
morphia :  long  ebullition  with  calcined 
magnesia,  a  series  of  nitrations,  and 
washings  and  dryings,  yield  very  pure 
morphia,  free  from  narcotine.  When 
the  resinous  matter  is  dissolved  in  dilute 
sulphuric  acid,  and  the  solution  decom- 
posed by  potash,  the  narcotine  is  preci- 
pitated, which  is  purified  by  a  fresh  solu- 
tion in  sulphuric  acid  and  precipitation 
by  ammonia,  and  this  often,  after  filtra- 
tion, washing,  and  re-dissolving  in  alco- 
hol of  0-903,  crystallizes.  A  pound  of 
opium  yields,  by  this  process,  8  drs.  of 
perfectly  pure  white  crystallized  mor- 
phia; or  it  may  be  obtained  by  fre- 
quently digesting  opium  in  muriatic  acid, 
adding  sea  salt,  and  saturating  with  am- 
monia. Wash  the  precipitate,  and  re- 
dissolve  in  acid,  filter,  and  cool.  The 
muriate  of  morphia  will  crystallize,  and 


may  be  separated  in  blotting  paper. 
Wash  with  pure  ammonia  to  decompose 
the  muriate,  dry  and  dissolve  in  alco- 
hol, and  finally  crystallize.  The  muriate 
and  sulphate  are  the  two  chief  prepara- 
tions. 

MORTAR  is  a  cement,  made  by  ex- 
pelling, by  fire,  the  carbonic  acid  of  car- 
bonate of  lime,  or  limestone,  and  mixing 
water  with  sand,  or  ashes,  as  a  paste. 
Then,  as  the  acid  speedily  recombines 
with  this  hydrate  of  lime,  the  mortar  sets 
as  limestone  again,  and  increases  in  hard- 
ness with  age.  Mortar  is  often  used  of 
two  qualities,  or  proportions  of  sand — ■ 
the  greater  for  inside  joints,  and  the  less 
for  outside  ;  in  which  the  sand- mortar, 
for  pointing,  is  often  mixed  -%  is  finer,  also, 
witla  forge-ashes,  but  white  cement  is 
also  used. 

Mortar,  for  paving,  is  improved  by 
mixing  the  residuum  of  the  distillation  of 
aquafortis. 

MORTAR,  HYDRAULIC,  called  also 
Roman  Cement,  is  the  kind  of  mortar 
used  for  building  piers,  or  walls  under  or 
exposed  to  water,  such  as  those  of  har- 
bors, docks,  &c.  The  poorer  sorts  of 
limestone  are  best  adapted  for  this  pur- 
pose, such  as  contain  from  8  to  25  per 
cent,  of  foreign  matter,  in  silica,  alumina, 
magnesia,  &c.  These,  though  calcined, 
do  not  slake  when  moistened;  but  if 
pulverized  they  absorb  water  without 
swelling  up  or  heating,  like/at  lime,  and 
aflbrd  a  paste  which  hardens  in  a  few 
days  under  water,  but  in  the  air  they 
never  acquire  much  solidity.  Smeaton 
first  discovered  these  remarkable  tacts, 
and  described  them  in  1759. 

The  following  analyses  of  different  hy- 
draulic limestones,  by  Berthier,  merit 
confidence : 


A.  Analyses  of  limestones. 

No.  1. 

No.  2. 

No.  3. 

No.  4. 

No.  5. 

97  0 
2-0 

1-0 

98-5 
15 

74  5 
230 

1-2 

76  5 
30 
3  0 
1-5 

j    15  2 

800 

Carbonate  of  magnesia 

Carbonate  of  protoxide  of  iron 
Carbonate  of  manganese 

15 
j      18-0 

100*0 

1000 

1000 

1000 

100-0 

All  good  hydraulic  mortars  must  con- 
tain alumina  and  silica;  the  oxides  of 
iron  and  manganese,  at  one  time  consid- 
ered essential,  are  rather  prejudicial  in- 


gredients. By  adding  silica  and  alumi- 
na, or  merely  the  former,  in  certain  cir- 
cumstances, to  fat  lime,  a  water-cement 
-iay  be  artificially  formed;    as  als"  by 


mor] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


381 


adding  to  lime  any  of  the  following  na- 
tive productions,  which  contain  silicates  ; 
puzzolana,  trass  or  tarrass,  pumice-stone, 
basalt-tuff,  slate-clay.  Puzzolana  is  a  vol- 
canic product,  which  forms  hills  of  con- 
siderable extent  to  the  south-west  of  the 
Apennines,  in  the  district  of  Koine,  the 
Pontine  marshes,  Viterbo,  Bolsena,  and 
in  the  Neapolitan  region  of  Puzzuolo, 
whence  the  name.  A  similar  volcanic 
tufa  is  found  in  many  other  parts  of  the 
world.  According  to  Berthier,  the  Ita- 
lian puzzolana  consists  of  44-5  silica; 
15-0  alumina ;  8*8  lime  ;  4-7  magnesia ; 
1-4  potash  ;  4*1  soda ;  12  oxydes  of  iron 
and  titanium  ;  9-2  water;  in  100  parts. 

The  tufa  stone,  which,  when  ground, 
forms  trass,  is  composed  of  57-0  silica, 
16-0  clay,  2-6  lime,  1-0  magnesia,  7-0  pot- 
ash, 1-0  soda,  5  oxides  ot  iron  and  tita- 
nium, 9-6  water.  This  tuff  is  found 
abundantly  filling  up  valleys  in  beds  of 
10  or  20  feet  deep,  in  the  north  of  Ireland, 
among  the  schistose  formations  upon  the 
banks  of  the  Rhine,  and  at  Manheim  in 
Bavaria. 

The  fatter  the  lime,  the  less  of  it  must 
be  added  to  the  ground  puzzolana  or 
trass,  to  form  a  hydraulic  mortar ;  the 
mixture  should  be  made  extemporane- 
ously, and  must  at  any  rate  be  kept  dry 
till  about  to  be  applied.  Sometimes  a  pro- 
portion of  common  sand  mortar  instead 
of  lime  is  mixed  with  the  trass.  "When 
the  hydraulic  cement  hardens  too  soon,  as 
in  12  "hours,  it  is  apt  to  crack  ;  it  is  better 
when  it  takes  8  days  to  concrete.  Through 
the  agency  of  the  water,  silicates  of  lime, 
alumina  (magnesia),  and  oxyde  of  iron 
are  formed,  which  assume  a  stony  hard- 
ness. 

In  England  the  stones  are  calcined  in 
shaft-kilns,  or  sometimes  in  mound-kilns, 
then  ground,  sifted,  and  packed  in  casks. 
The  color  of  the  powder  is  dark-brown 
red.  When  made  into  a  thick  paste  with 
water,  it  absorbs  little  of  it,  evolves  hard- 
ly any  heat,  and  soon  indurates.  It  is 
mixed  with  sharp  sand  in  various  pro- 
portions, immediately  before  using  it; 
and  is  employed  in  all  marine  and  river 
embankments,  for  securing  the  seams  of 
stone  or  brick  floors  or  arches  from  the 
percolation  of  moisture,  and  also  for 
Facing  walls  to  protect  them  from 
damp. 

The  cement  of  Pouilly  is  prepared  from 
a  Jurassic  (secondary)  limestone,  which 
contains  39  per  cent,  of  silica,  with  alu- 
mina, magnesia,  and  iron  oxide.  Vicat 
forms  a  factitious  Roman  cement  by  mak- 
ing bricks  with  a  pasty  mixture  of  4  part& 


of  chalk,  and  1  part  of  dry  clay,  drying. 
burning,  and  grinding  them.  River  sand 
must  be  added  to  this  powder ;  and  even 
with  this  addition,  its  efficacy  is  some- 
what doubtful ;  though  it  has,  fcr  want 
of  a  better  substitute,  been  much  em- 
ployed at  Paris. 

The  cement  of  Dihl  consists  of  porce- 
lain or  salt-glaze  potsherds  ground  fine, 
and  mixed  with  boiled  linseed  oil. 

All  sorts  of  lime  are  made  hydraulic, 
in  the  humid  way,  by  mixing  slaked  lime 
with  solutions  of  common  alum  or  sul- 
phate of  alumina ;  but  the  best  method 
consists  in  employing  a  solution  of  the 
silicate  of  potash,  called  liquor  of  flints, 
or  soluble  glass,  to  mix  in  with  the  lime, 
or  lime  and  clay.  A  hydraulic  cement 
may  also  be  made  which  will  serve  for 
the  manufacture  of  architectural  orna- 
ments, by  making  a  paste  of  pulverized 
chalk,  with  a  solution  of  the  silicate  of 
potash.  The  said  liquor  of  flints  will  like- 
wise give  chalk  and  plaster  a  stony  hard- 
ness, by  merely  soaking  them  in  it  after 
they  are  cut  or  moulded  to  a  proper  shape. 
On  exposure  to  the  air,  they  get  progres- 
sively indurated.  Superficial  hardness 
may  be  readily  procured  by  washing  over 
the  surface  of  chalk,  &c,  with  liquor  of 
flints,  by  means  of  a  brush.  This  method 
affords  an  easy  and  elegant  method  of 
giving  a  stony  crust  to  plastered  walls  and 
ceilings  of  apartments  ;  as  also  to  statues 
and  busts,  cast  in  gypsum,  mixed  with 
chalk. 

The  essential  constituents  of  every 
good  hydraulic  mortar,  are  caustic  lime 
and  silica ;  and  the  hardening  of  this  com- 
pound under  water  consists  mainly  in  a 
chemical  combination  of  these  two  con- 
stituents through  the  agency  of  the  water, 
producing  a  hydrated  silicate  of  lime.  But 
such  mortars  may  contain  other  bases  be- 
sides lime,  as  for  example  clay  and  mag- 
nesia, whence  double  silicates  of  great 
solidity  are  formed ;  on  which  account 
dolomite  is  a  good  ingredient  of  these 
mortars.  But  the  silica  must  be  in  a  pe- 
culiar state  for  these  purposes  ;  namely, 
capable  of  affording  a  gelatinous  paste 
with  acids  ;  and  if  not  so  already,  it  must 
be  brought  into  this  condition,  by  calcin- 
ing it  along  with  an  alkali  or  an  alkaline 
earth,  at  a  bright  red  heat,  when  it  will 
dissolve,  and  gelatinize  in  acids.  Quart- 
zose  sand,  however  fine  its  powder  may 
be,  will  form  no  mortar  with  lime :  but  if 
the  powder  be  ignited  with  the  lime,  it 
then  becomes  fit  for  hydraulic  work. 
Ground  felspar  or  clay  forms  with  slaked 
lime   no  water  cement ;  but  when  they 


382 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[mos 


are  previously  calcined  along  with  the 
lime,  the  mixture  becomes  capable  of 
hardening  under  water. 

The  mastic  called  Hamelin's,  and  so 
much  employed  in  London,  is  composed 
of  ground  Portland  stone  (roe  stone), 
sand,  and  litharge,  in  the  proportion  of 
62  of  the  first,  35  of  the  second,  and  3  of 
the  third,  in  100  parts  ;  but  other  propor- 
tions will  also  answer  the  purpose.  Chalk 
will  not  make  a  good  mastic,  being  too 
compact  to  permit  the  air  to  insinuate  be- 
tween the  pores,  and  to  produce  the  con- 
cretion of  the  linseed  oil,  with  which  the 
above  mixture  is  worked  up  and  applied. 
This  mastic  soon  acquires  great  hard- 
ness, and  is  totally  impervious  to  water. 
The  surface  to  which  it  is  to  be  applied 
must  be  dry,  and  smeared  over  with  lin- 
seed oil.  Considerable  dexterity  is  re- 
quired to  make  good  work  with  it.  The 
fine  dust  of  sandstone  alone,  mixed  with 
10  or  12  per  cent,  of  litharge,  and  7  per 
of  linseed  oil,  forms  an  excellent  mastic. 

Limestone,  which  contains  so  much  as 
10  per  cent,  of  clay,  comports  itself  after 
calcination,  if  all  the  carbonic  acid  be  ex- 
pelled, just  as  pure  limestone  would  do. 
When  it  is  less  strongly  burned,  it  affords, 
however,  a  mass  which  hardens  pretty 
speedily  in  water.  If  the  argillaceous 
proportion  of  a  marl  amounts  to  18  or  20 

Eer  cent.,  it  still  will  slake  with  water, 
ut  it  will  absorb  less  of  it,  and  forms  a 
tolerably  good  hydraulic  mortar,  especial- 
ly if  a  little  good  Eoman  cement  be  added 
to  it.  When  the  proportion  of  clay  is  25 
or  30  per  cent,  after  burning,  it  heats  but 
little  with  water,  nor  does  it  slake  well, 
and  must  therefore  be  ground  by  stam- 
pers or  an  edge  millstone,  when  it  is  to 
be  used  as  a  mortar.  This  kind  of  marl 
yields  commonly  the  best  water  cement 
without  other  addition.  Should  the 
quantity  of  clay  be  increased  further,  as 
up  to  40  per  cent.,  the  compound  will  not 
bear  a  high  or  long-continued  heat  with- 
out being  spoiled  for  making  hydraulic 
mortar  after  grinding  to  powder.  When 
more  strongly  calcined,  it  forms  a  vi  tri- 
form substance,  and  should,  after  being 
pulverized,  be  mixed  up  with  good  lime, 
to  make  a  water  mortar. 

The  Manliu*  or  water  limestones  of  the 
New-York  system  of  rocks,  furnishes  in 
some  of  its" courses,  when  quarried,  a 
very  good  water  cement,  but  the  compo- 
sition of  the  stone  varies  in  different 
g laces.  Some  of  this  rock,  taken  from 
outh  Fayette,  Seneca  Co.,  N.  Y.,  afforded 
to  the  Editor,  on  treatment  by  muriatic 
acid,  the  following  composition: 


Soluble  in  muriatic  acid- 
Silica 4-0 

Alumina 4  5 

Oxide  of  Iron 5 

Carbonate  of  Lime 15  0 

Magnesia 11  0 

Oxide  of  Manganese . . 2  0 

37  0 
Insoluble  in  acid — 

Silicates  of  Alumina  and 

Iron 63-0 

100  0 

There  was  apparently  in  this  stone  too 
much  silica,  and  too  small  a  proportion 
of  lime,  to  make  a  good  hydraulic  stone. 

MOSAIC  GOLD.  For  the  composi- 
tion of  this  peculiar  alloy  of  copper  and 
zinc,  called  also  Or-molu,  Messrs.  Parker 
and  Hamilton  obtained  a  patent  in  No- 
vember, 1825.  Equal  quantities  of  copper 
and  zinc  are  to  be  "  melted  at  the  lowest 
temperature  that  copper  will  fuse,"  which 
being  stirred  together  so  as  to  produce  a 
perfect  admixture  of  the  metals,  a  further 
quantity  of  zinc  is  added  in  small  por- 
tions, until  the  alloy  in  the  melting-pot 
becomes  of  the  color  required.  If  the 
temperature  of  the  copper  be  too  high,  a 
portion  of  the  zinc  will  fly  off  in  vapor, 
and  the  result  will  be  merely  spelter  or 
hard  solder ;  but  if  the  operation  be  car- 
ried on  at  as  low  a  heat  as  possible,  the 
alloy  will  assume  first  a  brassy  yellow  co- 
lor ;  then,  by  the  introduction  of  small 
portions  of  zinc,  it  will  take  a  purple  or 
violet  hue,  and  will  ultimately  become 
perfectly  white ;  which  is  the  appearance 
of  the  proper  compound  in  its  fused  state. 
This  alloy  may  be  poured  into  ingots ; 
but  as  it  is  difficult  to  preserve  its  char- 
acter when  re-melted,  it  should  be  cast 
directly  into  the  figured  moulds.  The 
patentees  claim  the  exclusive  right  of 
compounding  a  metal  consisting  of  from 
52  to  55  parts  of  zinc  out  of  100. 

Mosaic  gold,  the  aurum  musivum  of  the 
old  chemists,  is  a  sulphuret  of  tin. 

MOSAIC.  There  are  several  kinds  of 
mosaic,  but  all  of  them  consist  in  imbed- 
ding fragments  of  different  colored  sub- 
stances, "usually  glass  or  stones,  in  a  ce- 
ment, so  as  to  produce  the  effect  of  a  pic- 
ture. The  beautiful  chapel  of  Saint  Law- 
rence in  Florence,  which  contains  the 
tombs  of  the  Medici,  has  been  greatly  ad- 
mired by  artists,  on  account  of  the  vast 
multitude  of  precious  marbles,  jaspars, 
agates,  avanturines,  malachites,  Ac,  ap- 
plied in  mosaic  upon  its  walls.  The  de- 
tailed discussion  of  this  subject  belongs 
to  a  treatise  upon  the  fine  arts. 


MUP] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


383 


The  latest  improvement  in  Mosaic  art 
has  been  effected  by  Mr.  Prosser,  of  Bir- 
mingham, England,  in  1840,  who  found 
that  if  the  material  of  porcelain  (a  mixture 
of  flint  and  fine  clay)  be  reduced  to  a  dry 
powder,  and  in  that  subjected  to  strong 
pressure  between  steel  dyes,  the  powder 
is  compressed  into  one  fourth  of  its  bulk, 
and  is  converted  into  a  compact  substance 
of  great  hardness  and  density ;  much  less 
porous,  and  much  harder  than  common 
porcelain,  uncompressed  and  baked  in 
the  furnace.  This  discovery  was  first  ap- 
plied to  the  manufacture  of  buttons  by 
Mr.  Prosser,  and  Mr.  Blashfield  applied  it 
to  the  formation  of  tesserae.  He  obtained 
cubes  thus  formed,  and  by  the  application 
of  these  in  any  forms,  as  squares  for  ter- 
sillation,  triangles  and  hexagons,  to  imitate 
the  opus  Alexandrinum,  polygons,  and 
rhomboids,  or  of  any  color,  and  by  enam- 
elling the  surface  with  the  most  brilliant 
tints  and  gold,  very  good  substitutes  for 
the  ancient  glass  mosaic  were  produced. 
They  are  cemented  together  in  a  pattern 
form  on  a  table  previously,  and  when 
hard  may  be  laid  down  on  the  required 
Bpot. 

MOTHER  OF  PEARL  is  the  hard 
silvery,  brilliant  internal  layer  of  several 
kinds  of  shells,  particularly  oysters,  which 
is  often  variegated  with  changing  purple 
and  azure  colors.  The  large  oysters  of 
the  Indian  seas  alone  secrete  this  coat  of 
sufficient  thickness  to  render  their  shells 
available  to  the  purposes  of  manufactures. 
The  genus  of  shell-fish  called  Pentadince 
furnishes  the  finest  pearls,  as  well  as 
mother  of  pearl ;  it  is  found  in  greater 

Serfection  round  the  coast  of  Ceylon,  near 
•rmus  in  the  Persian  Gulf,  at  Cape  Com- 
orin,  and  among  some  of  the  Australian 
seus.  The  brilliant  hues  of  mother  of 
pearl  do  not  depend  upon  the  nature  of 
the  substance,  but  upon  its  structure. 
The  microscopic  wrinkles  or  furrows 
which  run  across  the  surface  of  every 
Blice  act  upon  the  reflected  light  in  such 
a  way  as  to  produce  the  chromatic  effect ; 
for  Sir  David  Brewster  has  shown,  that 
if  we  take,  with  very  fine  black  wax,  or 
with  the  fusible  alloy  of  D' Arcet,  an  im- 
pression of  mother  of  pearl,  it  will  possess 
the  iridescent  appearance.  Mother  of 
pearl  is  very  delicate  to  work  ;  but  it  may 
be  fashioned  by  saws,  files,  and  drills, 
with  the  aid  sometimes  of  a  corrosive 
acid,  such  as  the  dilute  sulphuric  or  mu- 
riatic ;  and  it  is  polished  by  colcothar  of 
vitriol. 

MOTHER  WATER.  A  term  applied 
by  chemists  to  saline  solutions  from  which 


crystals  have  been  deposited,  and  which, 
when  poured  off  and  re- evaporated,  fur- 
nish a  second  crop. 

MOTION.  In  mechanical  philosophy, 
motion  is  the  change  of  place :  that  is,  of 
the  part  of  space  which  the  body  occu- 
pies, or  in  which  it  is  extended.  Motion 
is  real  or  absolute  when  the  moving  body 
changes  its  place  in  absolute  space ;  it  is 
relative  when  the  body  changes  its  place 
only  with  relation  to  surrounding  bodies  ; 
and  it  is  apparent  when  the  body  changes 
its  situation  with  respect  to  other  bodies 
that  appear  to  us  to  be  at  rest.  All  the 
phenomena  of  motion  are  derived  by 
mathematical  deductions  from  the  three 
following  laws  of  motion  of  Newton  : 

1.  A  body  must  continue  for  ever  in  a 
state  of  rest,  or  of  uniform  motion  in  a 
straight  line,  if  it  be  not  disturbed  by  the 
action  of  an  external  cause. 

2.  Every  change  of  motion  produced 
by  any  external  force  is  proportional  to 
the  force  impressed,  and  in  the  direction 
of  the  straight  line  in  which  the  force 
acts. 

3.  Action  and  reaction  are  equal  and  in 
contrary  directions ;  that  is,  equal  and 
contrary  changes  of  motion  are  produced 
on  bodies  which  mutually  act  on  each 
other. 

MOULDINGS,  in  architecture,  are  the 
annular,  the  astragal  or  bead,  the  ogee, 
the  cuna  recta,  the  cavetto  or  hollow,  the 
ovolo,  the  scotia,  and  the  torus. 

MOULDINESS  may  be  retarded  by  the 
presence  of  aromatics.  It  is  a  plant  pro- 
pagated bv  seeds. 

MOUNTAIN  SOAP  is  a  tender  mine- 
ral, soft  to  the  touch,  which  assumes  a 
greasy  lustre  when  rubbed,  and  falls  to 
pieces  in  water.  It  consists  of  silica  44, 
alumina  26*5,  water  20*5,  oxide  of  iron  8, 
lime  0-5.  It  occurs  in  beds,  alternating 
with  different  sorts  of  clay,  in  the  Isle  of 
Skye,  at  Billin  in  Bohemia,  &c.  It  has 
been  often,  but  improperly,  confounded 
with  steatite. 

MUCIC  ACID  is  the  same  as  the  sac- 
lactic  acid  of  Scheele,  and  may  be  obtained 
by  digesting  one  part  of  gum  arabic,  su- 
gar of  milk,  or  pectic  acid,  with  twice  or 
thrice  their  weight  of  nitric  acid.  It  forms 
white  granular  crystals,  and  has  not  been 
applied  to  any  use  in  the  arts. 

MUCILAGES  are  gummy  solutions,  in 
water,  of  lacacia,  gum  arabic,  tragacinth, 
and  starch.  They  are  also  common  ani- 
mal and  vegetable  fluids. 

MUDARINE.  The  root  of  the  mudar 
or  mudhar  plant,  the  calotropis  mvdarii, 
of  Hamilton,  belonging  to  the  asclepiadec^ 


884 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[mur 


well  known  in  the  East  as  a  powerful 
medicine.  The  most  remarkable  pecu- 
liarity of  mudarine  is,  that  its  solubility 
in  water  diminishes  as  the  temperature 
increases.  A  concentrated  solution, 
which  is  perfectly  transparent  and  fluid 
at  50^°,  has  its  transparency  diminished, 
and  gelatinizes  at  a  little  above  70°.  On 
being  allowed  to  cool,  the  jelly  melts,  and 
regains  its  former  fluidity.  If  the  tem- 
perature be  raised  considerably  above  70°, 
the  jelly  contracts  and  separates  from  a 
liquid,  and  it  has  lost  its  power  of  resum- 
ing its  liquid  state  on  reduction  of  tem- 
perature. 

MUFFLE  is  the  name  of  a  system  of 
double  pulleys,  moved  together  with  pa- 
rallel cords,  the  power  of  which  is  as  the 
number  of  cords  at  the  lower  block.  It 
is  also  a  portable  oven  or  furnace. 

MULBERRY,  a  very  important  genus 
of  trees,  morus,  allied  to  the  nettle,  and 
belonging  to  the  natural  family  urticea, 
whose  fruit  yields  tartaric  acid,  and  is 
edible,  its  leaves  silk,  its  bark  paper  and 
useful  wood.  The  black  species  produce 
the  best  fruit,  the  white,  such  leaves  as 
silk-worms  prefer,  and  in  which  the  fi- 
brous tissue  is  visible ;  and  the  paper  spe- 
cies, of  whose  fibrous  bark  cloth  is  made 
in  the  South  Sea  Islands,  raid  paper  in 
Japan.  It  grows  40  feet  high,  and  the 
trunk  about  2  feet  in  diameter.  It  is  nat- 
uralized now  in  Europe. 

The  quickest  and  most  certain  mode 
of  raising  the  mulberry-tree  is,  from  cut- 
ting the  old  branches.  Take  a  branch  in 
the  month  of  March,  eight  or  nine  feet 
in  length,  plant  it  half  its  length  in  any 
good  soil,  and  it  will  produce  fruit  the 
following  year.  But  the  most  approved 
mode  of  cultivation  is  from  seed. 

In  this  country  the  white  mulberry 
flourishes  from  the  43d  to  the  32d  degree 
of  latitude.  The  leaves  of  the  black  mul- 
berry are  sometimes  substituted  for  food 
for  silk- worms.  The  moru#  rubra,  or  red 
mulberry,  is  a  native  of  the  United  States, 
and  is  valuable  on  account  of  the  proper- 
ties of  the  wood.  It  is  abundant  on  the 
Ohio,  its  tributaries,  and  lower  part  of 
the  Missouri;  the  wood  is  fine-grained, 
compact,  and  solid.  It  is  employed  in 
ship-building  at  Baltimore  and  Philadel- 
phia, for  the  upper  and  lower  parts  of  the 
frame,  for  the  knees  and  floor  timbers, 
and  for  tree -nails.  It  is  not  inferior  to 
the  locust-wood.  The  leaves  do  not  ap- 
pear fit  for  silk-worms. 

MULE,  in  manufactures,  is  a  machine, 
invented  by  Crompton,  in  1799,  for  pro- 
ducing finer  yarn,  and  has  now  quite  su- 


perseded the  jenny.  For  producing 
threads  of  the  finest  kind,  a  process  is 
necessary  which  is  called  stretching,  and 
analogous  to  that  which  is  performed  with 
carded  cotton  upon  a  common  spinning- 
wheel.  The  spindles  are  mounted  upon 
a  carriage,  which  is  moved  backwards 
and  forwards  across  the  floor,  receding 
when  the  threads  are  to  be  stretched, 
and  returning  when  they  are  to  be  wound 
up.  The  yarn  produced  by  mule-spin- 
ning is  employed  in  the  fabrication  of 
the  finest  articles,  and  threads  have  been 
produced  of  such  fineness,  that  a  pound 
of  cotton  has  been  extended  to  300  hanks, 
or  167  miles. 

MULLER  is  the  name  of  a  stone  for 
grinding  colors,  usually  flat,  and  worked 
with  the  hand,  or  with  a  horse  and  a 
wheel.  But  a  concave  muller  has  been 
invented,  which,  being  placed  vertically, 
and  the  concavity  supplied  with  rough 
color,  it  is  pressed  and  worked  by  another 
stone,  worked  with  a  winch  or  power. 
The  muller  is  a  segment  of  the  turning- 
stone. 
.  MULTUM  (for  brewers,  instead  of  malt 
and  hops).  To  each  quart  of  extract  of 
quassia  add  40  oz.  of  liquorice  root. 

MUNDIC.  A  name  given  to  copper 
pyrites.  It  was  comparatively  useless 
until  lately,  when  it  was  introduced  into 
the  manufacture  of  soda-ash,  from  a 
knowledge  of  the  fact  of  its  ready  conver- 
sion, by  heat  and  an  alkali,  into  a  sulphate 
of  the  alkali  and  peroxide  of  iron.  The 
sulphuric  acid  being  thus  produced  by 
the  oxygen  of  the  air  alone,  sulphur  ores, 
hitherto  valueless,  are  thus  rendered 
more  valuable.  Since  the  introduction 
of  this  process,  chlorine  has  been  obtain- 
ed by  causing  the  oxygen  of  the  air  to  act 
on  the  chloride  of  iron,  oxidising  the  iron 
and  setting  the  chlorine  free.  The  cost 
of  making  soda  is  reduced  by  this  pro- 
cess, and  thus  soap,  soda,  and  glass,  can 
be  had  on  cheaper  terms.  It  consists  of 
copper  30,  sulphur  87,  iron  33,  in  100  parts. 

MURI ACITE.  An  anhydrous  sulphate 
of  lime,  containing  a  little  common  salt. 

MURIATIC  ACID,  or  Hydro- 
chloric Acid.  This  acid  was  originally 
discovered  by  Glauber,  and  called  by  him 
spirit  of  salt.  In  its  pure  or  gaseous  form 
it  was  first  obtained  by  Priestley  in  1744 ; 
and  its  true  composition  was  shown  by 
Davy  in  1809,  who  proved  it  to  be  a  com- 
pound of  hydrogen  and  chlorine  j  hence 
it  has  been  termed  hydrochloric  arid. 
Muriatic  acid  gas  is  procured  by  acting 
upon  common  salt  (which  is  a  chloride 
or  sodium)  by   concentrated    sulphuric 


MUs] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


$85 


acid.  The  water  of  the  acid  is  decom- 
posed, and  its  hydrogen  combines  with 
the  chlorine  of  the  salt  to  form  muriatic 
acid ;  while  the  oxygen  is  transferred  to 
the  sodium,  which  is  thus  converted  into 
soda,  and  this  unites  to  the  sulphuric 
acid  to  form  sulphate  of  soda.  60  parts 
of  common  salt,  and  49  parts  of  concen- 
trated sulphuric  acid,  afford,  by  this 
mutual  action,  37  parts  of  muriatic  acid, 
and  72  of  sulphate  of  soda.  Muriatic 
acid  gas  may  also  be  formed  by  passing 
an  electric  spark  through  a  mixture  of 
equal  volumes  of  chlorine  and  hydrogen ; 
or  by  exposing  such  mixture  to  the  sun's 
rays,  or  inflaming  them  by  a  taper,  they 
burn  with  explosion,  and  form  a  volume 
of  muriatic  acid  equal  to  the  united  vol- 
umes of  the  gases.  As  the  specific  gra- 
vity of  hydrogen  is  to  that  of  chlorine  as 
1  to  36,  the  specific  gravity  of  the  result- 
ing muriatic  acid  gas  compared  with  hy- 
drogen will  be  18-5,  and  100  cubic  inches 
of  it  will  weigh  39-3  grains.  Muriatic  acid 
gas  is  rendered  liquid  under  a  pressure 
of  40  atmospheres  of  the  temperature  of 
60°  ;  it  extinguishes  flame,  and  is  intense- 
ly sour,  powerfully  reddening  vegetable 
blues.  Water  absorbs  it  with  much  vio- 
lence, taking  up  about  480  times  its  vol- 
ume. This  is  the  state  in  which  muriatic 
acid  is  generally  used.  Its  specific  gravity 
is  about  1*19,  and  it  is  commonly  obtain- 
ed by  distilling  a  mixture  of  equal  weights 
of  salt,  sulphuric  acid,  and  water.  When 
muriatic  acid  acts  upon  metallic  oxides, 
it  generally  happens  that  a  mutual  de- 
composition of  the  oxide  and  acid  ensues ; 
the  oxygen  of  the  oxide  unites  to  the 
hydrogen  of  the  acid  to  form  water,  and 
the  metal  to  the  chlorine  to  form  a  metal- 
lic chloride.  Thus  it  is  that  soda  and 
muriatic  acid  form  a  chloride  of  sodium 
or  common  salt.  The  most  effective  test  of 
the  presence  of  muriatic  acid  is  nitrate  of 
silver,  which  forms  an  insoluble  chloride 
of  silver  in  all  solutions  containing  muri- 
atic acid  or  muriates. 

The  muriatic  acid  of  commerce  has 
usually  a  yellowish  tinge,  but  when 
chemically  pure  it  is  colorless.  It  fumes 
strongly  in  the  air,  emitting  a  corrosive 
vapor  of  a  peculiar  smell.  The  straw 
color  is  due  to  the  presence  of  chloride 
of  iron,  obtained  from  the  vessel  in  which 
it  was  made.  It  may  be  freed  from  this 
by  distillation. 

The  preparation  of  this  acid  upon  a 
great  scale  is  frequently  effected  in  this 
country  by  acting  upon  sea-salt  in  hem- 
ispherical iron  pots,  or  in  cast-iron  cy- 
linders, with  concentrated  sulphuric  acid ; 
17 


taking  6  parts  of  the  salt  to  5  of  the  acid. 
The  mouth  of  the  pot  may  be  covered 
with  a  slab  of  silicious  freestone,  perfo- 
rated with  two  holes  of  about  two  inches 
diameter  each,  into  the  one  of  which  the 
acid  is  poured  by  a  funnel  in  successive 
portions,  and  into  the  other,  a  bent  glass, 
or  stone-ware  tube,  is  fixed,  for  couduct- 
ing  the  disengaged  muriatic  gas  into  a 
series  of  large  globes  of  bottle  glass,  one- 
third  filled  with  water,  and  laid  on  a  slop- 
ing sand-bed.  A  week  is  commonly  em- 
ployed for  working  off"  each  pot;  no  beat 
being  applied  to  it  till  the  second  day. 

Liquid  muriatic  acid  has  a  very  s</ur 
corrosive  taste,  a  pungent  suffocating 
smell,  and  acts  very  powerfully  upon  a 
vast  number  of  mineral,  vegetable,  and 
animal  substances.  It  is  much  employed 
for  making  many  metallic  solutions  ;  and 
in  combination  with  nitric  acid,  it  forms 
the  aqua  regia  of  the  alchemists,  so  called 
from  its  property  of  dissolving  gold. 

MUSK  is  a  peculiar  aromatic  substance, 
found  in  a  sac  between  the  navel  and  the 
parts  of  generation  of  a  small  male  quad- 
ruped of  the  deer  kind,  called  by  Lin- 
naeus, Moschus  moschiferus,  which  in- 
habits Tonquin  and  Thibet.  The  coloi 
of  musk  is  blackish-brown;  it  is  lumpy 
or  granular,  somewhat  like  dried  blood, 
with  which  substance,  indeed,  it  is  often 
adulterated.  The  intensity  of  its  smell 
is  almost  the  only  criterion  of  its  genuine- 
ness. When  thoroughly  dried  it  oecomes 
nearly  scentless  ;  but  it  recovers  its  odor 
when  slightly  moistened  with  water  of 
ammonia.  The  Tonquin  musk  is  most 
esteemed.  It  comes  to  us  in  small  bags 
covered  with  a  reddish-brown  hair ;  the 
bag  of  the  Thibet  musk  is  covered  with  a 
silver-gray  hair.  All  the  analyses  of  musk 
hitherto  made  teach  little  or  nothing  con- 
cerning its  active  or  essential  constituent. 
It  is  used  in  medicines,  and  is  an  ingre- 
dient in  a  great  many  perfumes. 

Musk  (artificial,),  is  made  of  rectified 
oil  of  amber  one  part,  nitric  acid  four 
parts,  and  digested.  Black  matter  is  de- 
posited, to  be  well  washed  in  water,  and 
it  smells  similar  to  musk  or  ambergris, 
and  may  be  used  for  them. 

Mush  Bolv8.  Mix  in  simple  syrup  15 
grains  of  musk  with  5  grains  of  camphor, 
Or,  with  conserve  of  roses,  half  a  scruple 
of  musk  and  of  sal  ammoniac. 

MUSKETS  are  bored,  on  the  principle 
of  turning,  from  a  square  length  of  iron, 
welded  on  a  mandrel  by  heat'into  cylin- 
ders. In  forming  the  spirals  of  rifle  barrels, 
the  borer  is  conducted  by  a  matrix  or  fe- 
male screw,  which  revolves  in  2  feet,  and 


386 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[MAI 


the  borer  is  fixed  to  a  male  screw.     The 

Sural  threads  in  a  barrel  are  from  3  to  12. 
annon  are  cast  as  cylinders,  and  then 
bored. 

The  cylinders  of  steam  engines  are  of 
solid  cast-iron,  bored  in  the  usual  man- 
ner, by  forcing  the  cutters  by  a  train  of 
wheels  towards  the  solid  cylinder. 

MUSLIN,  a  fine  cotton  fabric,  used  in 
ladies'  dress.  It  is  manufactured  either 
white,  dyed,  or  printed.  It  is  also  em- 
ployed in  artificial  flower  making. 

MUST.  The  expressed  pice  of  the 
grape  before  its  conversion  into  wine  by 
the  process  of  fermentation. 

MUSTARD.  The  seed  of  the  Sinapis 
alba  and  nigra,  ground  into  powder,  and 
freed  from  the  husks :  it  is  the  well- 
known  condiment  of  the  shops,  or  at 
least  a  part  of  it;  for,  in  order  to  reduce 
the  strength  of  the  pure  mustard,  there 
is  generally  a  considerable  quantity  of 
wheaten  flour  added.  Brown  mustard 
should  be  the  flour  of  Sitiapis  nigra  ex- 
clusively, which  is  much  more  pungent 
than  the  other.  A  dessert  spoonful  of 
coarsely  powdered  mustard-seed,  taken 
in  a  glass  of  water,  generally  operates  as 
an  emetic;  it  is  also  aperient.  A  mus- 
tard poultice,  or  sinapism,  is  sometimes  a 
useful  stimulant. 

Patent  Mustard.  In  15  gallons  of  water 
boil  10  lbs.  of  salt,  and  12  lbs.  of  black 
ginger,  strain,  and  to  each  gallon  add  5 
lbs.  of  flour  of  mustard. — For  Moutarde 
a  Vestragon.  In  a  quart  of  Terragona 
sugar  mix  2  oz.  of  salt,  and  1  lb.  of  black 
mustard-seed,  much  dried,  and  finely 
powdered.  This  is  the  favorite  French 
mustard. 

MYRICINE,  contained  in  beeswax, 
which  contains  from  20  to  30  per  cent. ; 
it  remains  behind  when  the  wax  is  treat- 
ed by  alcohol. 

MYRRH.  This  gum  resin  is  imported 
from  Turkey ;  it  is  in  regular  tears  and 
lumps,  of  a  reddish  brown  color,  a  fra- 
grant odor,  and  a  warm  but  bitter  taste. 
It  is  probably  the  produce  of  a  species  of 
Amyris,  said  to  be  a  native  of  Abyssinia 
and  Arabia  Felix.  It  is  a  good  stimulat- 
ing tonic  medicine,  and  is  given  in  doses 
of  from  five  to  twenty  grains. 

MYRTLE  WAX  is  a  concrete  oil,  or 
vegetable  wax,  the  product  ot  the  class  of 
plants  myrica,  known  by  the  name  of 
candleberry  myrtle.  It  has  too  long  been 
considered  merely  as  an  object  of  curi- 
osity. The  plant  abounds  in  nearly  all 
parts  of  North  America,  and  varies  in 
Bize  from  4  to  18  feet,  becoming  taller  as 
it  extends  into  warmer  regions.      The 


bush  or  tree  has  somewhat  the  appear- 
ance of  the  common  myrtle,  and  bears  a 
berry  of  the  size  of  the  pepper-grain  or 
coriander-seed.  These  grains  are  of  a 
common  ash-color,  containing  a  small, 
round,  hard  kernel,  which  is  covered 
with  a  shining  wax,  that  may  be  obtain- 
ed by  boiling  the  grains  in  water.  The 
wax  is  prepared  for  commerce  along  the 
Canadian  lakes,  and  might,  by  proper 
attention,  be  rendered  an  important  arti- 
cle of  traffic.  Tapers  made  of  it,  emit, 
when  burning,  the  most  delicious  and 
balsamic  odor,  and  the  light  is  white  and 
intense,  equal  to  the  best  wax-candles. 

NAILS  are  commonly  made  by  hand 
by  men  or  women,  and  also  by  machine- 
ry, invented  by  Church,  the  facility  of 
which  is  so  great,  that  the  daily  product 
is  that  of  12  workmen.  A  nail-smith,  in 
Stirling,  lately  undertook  to  make  17,000 
double  flooring  nails,  1200  to  a  thousand  of 
20  lbs.,  for  two  successive  weeks.  He  fin- 
ished his  first  week's  task  by  3  o'clock  on 
Saturday  afternoon  ;  resumed  his  labor 
on  Monday  morning,  and  concluded  his 
second  week's  task  with  more  ease  than 
the  first.  The  quantity  was  as  much  as 
three  ordinary  men  can  perform,  and  allow 
ing  25  strokes  of  the  hammer  (which  was 
two  lbs.  weight)  to  each  nail,  there  were 
no  less  than  1,033,656  strokes  required. 
In  addition  to  this  he  had  to  give  from 
one  to  three  blasts  with  his  bellows  for 
every  nail,  and  had  to  move  from  the 
fire-place  upwards  of  42,836  times. 

In  Great  Britain  the  majority  of  nails 
are  hand-made  :  in  this  country  they  are 
almost  altogether  machine-made.  In  the 
nail-cutting  machine  they  can  be  made 
for  one-third  the  cost  of  wrought  nails, 
to  which  they  are  superior  for  many  pur- 
poses. The  iron,  after  being  rolled  into 
plates  and  slit  into  rods,  is  flattened  to 
the  thickness  of  the  future  nail  by  a 
second  rolling.  The  end  of  the  plate  is 
then  presented  to  the  nail-machine,  by 
a  workman,  who  turns  the  plate  over  once 
for  every  nail.  The  machine  has  a  rapid 
reciprocating  motion,  and  cuts  off  at  every 
stroke  a  wedge-shaped  piece  of  iron, 
constituting  a  nail  without  ahead.  This 
is  immediately  caught  near  its  largest 
end,  and  compressed  between  gripes  ;  at 
the  same  time,  a  strong  force  is  applied 
to  a  die  at  the  extremity,  which  spreads 
the  iron  sufficiently  to  form  the  head  to 
the  nail.  Some  nails  are  made  of  cast 
iron,  but  these  are  always  brittle,  unless 
afterwards  they  be  converted  into  mallea- 
able  iron  by  the  requisite  process. 
JDr.  Ure  makes  the  following  interest- 


han] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


387 


ing  quotation  from  a  report  of  the  Sec- 
retary of  State  for  Massachusetts  : 

"To  northern  carpenters,  it  is  well 
known  that  in  almost  all  instances  it  is 
unnecessary  to  bore  a  hole  before  driving 
a  cut  nail ;  all  that  is  requisite  is,  to  place 
the  cutting  edge  of  the  nail  across  the 
grain  of  the  wood  ;  it  is  also  true,  that 
cut  nails  will  hold  better  in  the  wood. 
These  qualities  are,  in  some  rough  build- 
ing works,  worth  twenty  per  cent,  of  the 
value  of  the  article,  which  is  equal  to  the 
whole  expense  of  manufacturing.  For 
sheathing  and  drawing,  cut  nails  are  full 
as  good  as  wrought  nails  ;  only  in  one 
respect  are  the  best  wrought  nails  a  little 
superior  to  cut  nails,  and  that  is  where  it  is 
necessary  they  should  be  clinched.  The 
manufacture  of  cut  nails  was  born  in  our 
country,  and  has  advanced,  within  its 
bosom,  through  all  the  various  stages  of 
infancy  to  manhood  ;  and  no  doubt  we 
shall  soon  be  able,  by  receiving  proper 
encouragement,  to  render  them  superior 
to  wrought  nails  in  every  particular. 

"  The  principal  business  of  rolling  and 
slitting-mills,  is  rolling  nail  plates  ;  they 
also  serve'to  make  nail  rods,  noops,  tires, 
sheet  iron,  and  sheet  copper.  In  this 
State  we  have  not  less  than  twelve. 

"  These  mills  could  roll  and  slit  7000 
tons  of  iron  a  year  ;  they  now,  it  is  pre- 
sumed, roll  and  slit  each  year  about  3500 
tons,  2400  tons  of  which,  probably,  are 
cut  up  into  nails  and  brads,  of  such  a 
quality  that  they  are  good  substitutes  for 
hammered  nails,  and,  in  fact,  have  the 
preference  with  most  people,  for  the  fol- 
lowing reasons ;  viz.,  on  account  of  the 
sharp  corner  and  true  taper  wth  which  cut 
nails  are  formed  ;  they  may  be  driven 
into  harder  wood  without  bending  or 
breaking,  or  hazard  of  splitting  the  wood, 
by  which  the  labor  of  boring  is  saved, 
the  nail  one  way  being  the  same  breadth 
or  thickness  from  head  to  point." 

NANKEEN  is  a  cotton  cloth  of  a  beau- 
tiful color,  which  derives  its  name  from 
Nankin,  in  China,  from  which  place  it 
was  first  brought  to  Europe.  The  manu- 
factured nankeen  is  now  exported  largely 
to  China.  Many  suppose  that  true  nan- 
keen is  artificially  colored,  but  this  is  not 
so  ;  its  color  is  that  of  the  natural  cotton — 
a  peculiar  kind,  some  of  which  has  been 
successfully  cultivated  in  Georgia.  The 
color  of  nankeen  may  be  imitated  in  the 
most  perfect  manner,  and  in  every  case 
of  linen  drill  of  this  color,  may  be  set 
down  as  an  artificial  production/ 

To  produce  light  nankeen  shades,  the 
cotton  cloth  should    be    first    bleached 


white.  This  can  be  done  by  having  some 
of  the  chloride  of  lime  dissolved  in  cold 
water  in  a  tub,  using  the  clear  hot,  and 
handling  the  cloth  in  it  till  it  is  white, 
then  handling  it  in  a  clean  water,  made 
sour  to  the  taste,  in  a  tub,  by  vitrol,  and 
afterwards  washing  it  well.  It  is  then  fit 
to  be  dyed  :  to  do  this,  dissolve  one 
pound  of  copperas  in  half  a  gallon  of 
water,  and  dissolve  two  pounds  of  quick 
lime  in  10  gallons  of  water ;  then  let  t>oth 
solutions  settle.  Pour  off  five  gallons  of 
the  clear  lime  water  into  a  tub  of  clean  cold 
water,  sufficient  to  cover  the  cloth,  and 
allow  it  to  be  handled  by  the  selvedge  free- 
ly. Then  into  another  tub  of  cold  water, 
about  the  same  size  as  the  lime  water  tub. 
put  in  one  quarter  of  the  clear  dissolved 
copperas  ;  one  ounce  of  the  nitrate  of 
lead  may  be  dissolved  with  the  copperas  ; 
handle  the  cloth  well  for  five  or  ten  min- 
utes in  the  lime,  giving  it  three  selvedges 
from  end  to  end,  and  afterwards  wring 
and  shake  it.  It  is  now  to  be  handled 
the  same  way  in  the  copperas  solution, 
then  wrung  and  aired  for  ten  minutes. 
It  is  then  to  be  put  through  the  lime  and 
copperas  in  the  same  manner,  adding 
enough  of  the  strong  lime  and  copperas 
to  make  three  successive  dips,  airing 
well  out  of  the  copperas  every  time.  It 
is  then  put  through,  last,  a  clean  tub  of 
lime  water,  which  can  be  made  by  put- 
ting more  clean  water  among  the  two  lbs. 
of  lime,  letting  it  settle  and  using  the 
clear.  It  is  then  well  washed  in  water, 
then  in  a  strong  solution  of  soap,  ana 
afterwards  well  washed,  then  dried.  This 
will  also  dye  unbleached  cotton  cloth, 
which  will  be  somewhat  darker  in  the 
color.  The  quantities  of  lime  and  cop- 
peras given,  will  dye  30  yards  of  com- 
mon cloth.  Light  and  dark  shades  are 
produced  by  the  quantity  of  lime  and 
copperas  used,  and  the  number  of  dips 
given.  The  eye  will  judge  the  depth  of 
color  desired.  Unbleached  cotton  cloth 
should  be  boiled  for  about  one  hour  in 
lime  water,  then  washed  well  before  it  is 
dyed. 

'  Bleached  goods  sold  in  stores  are  diffi- 
cult to  color  level — they  always  spot, 
owing  to  some  chloride  of  lime  not  being 
thoroughly  washed  out  of  them.  The 
only  remedy  for  this  is  to  steep  the  cloth 
all  night  in  warm  water,  then  boil  it  in 
lime  water,  and  wash  it  well  before  it  is 
dyed  (and  it  would  be  all  the  better  to  be 
quickly  handled  in  hot  water,  made  sour 
with  vitriol,  and  then  well  washed).  This 
|  color  washes  well  in  strong  soap  suds, 
!  but  it  spots  brown  and  black,  if  tea, 


388 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[nap 


coffee,  or  any  solution  containing  galic 
acid,  gets  on  it. 

Madder  Nankeen.  This  is  the  best 
nankeen  color,  as  it  will  wash  beauti- 
fully in  soap,  and  not  to  be  affected  with 
weak  acids. 

Take  the  cotton  cloth  (unbleached)  and 
boil  it  well  in  strong  lime  water  for  four 
or  five  hours,  until  all  the  natural  oil 
which  is  contained  in  the  fibres  of  the 
cotton  is  removed — this  is  essential  to 
produce  a  good  nankeen.  If  any  of  the 
oleaginous  matter  is  left,  the  color  will 
be  too  reddish,  approaching  to  a  salmon 
color.  After  the  cotton  is  well  boiled,  it 
must  be  well  washed,  and  then  handled 
in  a  copper  or  tin  kettle,  kept  near  a 
scalding  heat  for  one  hour.  In  the  kettle 
should'be  plenty  of  water,  to  allow  free 
handling,  and  there  should  be  four  ounces 
of  alum  dissolved  in  it  for  every  pound 
weight  of  the  cotton.  The  goods  after 
this  are  washed  well,  and  then  put  into  a 
kettle  containing  clean  water,  and  four 
ounces  of  madder  to  every  pound.  It 
should  be  kept  at  a  scalding  heat  for 
nearly  one  hour,  when  a  beautiful  nan- 
keen color  will  be  the  result.  The  color 
is  made  deeper  in  the  shade  by  using 
more  stuff.  It  is  washed  out  of  the  mad- 
der and  is  dried.  If  the  cotton  cloth  was 
bleached  it  would  make  a  still  more 
beautiful  color.  By  putting  a  little  of 
yellow  oak  bark  among  the  madder,  it 
will  make  the  color  verge  more  upon  the 
yellow  shade. 

Another  way  to  dye  nankeen  is  to  boil 
annatto  among  pearlash  (one  ounce  will 
color  five  pounds),  and  then  mix  it  with 
hot  water  in  a  clean  vessel,  and  handle 
the  goods  in  it  for  fifteen  or  twenty  min- 
utes. This  color  is  beautiful,  but  fugi- 
tive ;  it  fades  with  the  sun  and  can  be 
boiled  out  with  soap.  It  is  of  this  color- 
ed stuff  that  so  many  yellow  faded  and 
spotted  pantaloons  are  made. 

In  many  cases,  the  ordinary  mode  of 
making  nankeen  varies  from  the  forego- 
ing processes,  and  consists  in  a  series  of 
operations,  nearly  as  follows  : 

The  clean  cotton  yarn  is  saturated  in  a 
solution  of  alum  till  it  will  sOak  in  no 
more  of  that  mordant.  It  is  then  gaUed, 
by  dipping  it  in  a  strong  bath  of  oak 
bark ;  then  washed  through  a  bath  of 
cream  of  lime  or  weak  sodalye,  until  the 
desired  shade  appears.  The  hanks  are 
then  rinsed,  squeezed,  and  aired,  and 
passed  through  a  bath  of  chloride  of  tin, 
to  brighten  up  the  color. 

NAPLES  YELLOW  is  a  fine  yellow 
pigment,  called  giaUolino,  in  Italy,  where 


it  has   been  long  prepared  by  a  secret 

{)rocess ;  for  few  of  the  recipes  which 
lave  been  published  produce  a  good 
color.  It  is  employed  not  only  in  oil- 
painting,  but  also  for  porcelain  and  en- 
amel. It  has  a  fresh,  brilliant,  rich  hue, 
but  is  apt  to  be  very  unequal  in  different 
samples. 

The  following  prescription  has  been 
confidently  recommended.  Twelve  parts 
of  metallic  antimony  are  to  be  calcined  in 
a  reverberatory  furnace,  along  with  eight 
parts  of  red  lead,  and  four  parts  of  oxide 
of  zinc.  These  mixed  oxides,  being  well 
rubbed  together,  are  to  be  fused  ;  and  the 
fused  mass  is  to  be  triturated  and  elutri- 
ated into  a  fine  powder.  Chromate  of 
lead  has  in  a  great  measure  superseded 
Naples  yellow.  A  native  paint  is  made 
from  a  species  of  lava. 

NAPHTHA,  the  most  fluid  bitumen, 
is  nearly  colorless,  but  of  a  yellowish 
tinge,  transparent,  and  emits  a  peculiar 
odor.  It  swims  on  water,  its  specific 
gravity  being  from  0-71  to  0-84.  It  burns 
with  a  bluish-white  fiame  and  thick 
smoke,  and  leaves  no  residue.  It  con- 
sists of  carbon,  82-2,  and  hydrogen,  14-8 ; 
being  the  only  fluid  destitute  of  oxygen. 
It  is  found  in  Persia,  in  the  peninsula  of 
Apcheron,  upon  the  western  shore  of  the 
Caspian  Sea,  where  it  rises  through  a 
marly  soil  in  the  form  of  vapor,  and,  be- 
ing made  to  flow  through  earthen  tubes, 
is  inflamed  for  the  purpose  of  assisting 
in  the  preparation  of  food.  It  is  collected 
by  sinking  pits  several  yards  in  depth, 
into  which  the  naphtha  flows.  It  is 
burned  in  lamps,  by  the  Persians,  instead 
of  oil.  Near  the  village  of  Amiano,  in 
the  state  of  Parma,  there  exists  a  spring, 
which  yields  this  substance  in  sufficient 
quantity  to  illuminate  the  city  of  Genoa, 
for  which  purpose  it  is  employed.  In  a 
coal  mine  near  Manchester,  England, 
there  is  a  spring  of  Naphtha,  welling  up 
between  the  seazns,  and  which  yields  150 
gallons  a  day. 

On  the  surface  of  Seneca  Lake,  New- 
York,  a  large  quantity  of  naphtha,  or 
"  rock  oil,"  floats  at  particular  periods  of 
the  year.  This  Seneca  rock  oil  is  de- 
rivea  from  the  bitumen  escaping  out  of 
the  shales  which  are  very  carbonaceous 
in  the  middle  counties  of  western  New- 
York.  The  shale  beds  dip  south  and  a 
little  west  under  the  waters  of  the  lake, 
and  where  the  opening  of  the  seams 
meets  the  water  at  the  bottom  of  the  lake 
the  bitumen  oozes  out,  and  rises  to  the 
surface.  There  are  many  other  localities 
on  this  continent,  whero  native  naphtha 


neb] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


389 


or  bitumen  is  found.  It  is  found  abund- 
antly in  Kentucky.  Any  highly  fossili- 
ferous  shale,  which  is  dark  colored  from 
the  large  quantity  of  vegetable  matter 
contained  in  it,  and  which  also  contains 
pyrites  disseminated  throughout,  gene- 
rally affords  naphtha.  Native  naphtha 
boils  at  201°  P. 

Artificial  Naphtha  is  obtained  by  the 
distillation  of  the  crude  coal-tar,  one  of 
the  residues  of  the  manufacture  of  coal- 
gas.  It  has  a  specific  gravity  of  *857,  and 
consists  of  carbon,  83*04;  hydrogen, 
12-31 ;  oxygen,  4-35.  Dr.  Ure  gives  the 
boiling  point  as  316°  ;  but  this  must  have 
been  a  very  impure  naphtha.  The  chief 
and  valuable  agent  in  coal  naphtha  is 
Benzole  (which  see),  which  is  obtained 
by  distilling  the  coal-oil  at  a  temperature 
not  exceeding  185°.  Coal  naphtha  is  a 
valuable  solvent  for  many  solid  hydro- 
carbons, as  gutta  percha  and  caoutchouc 
and  when  pure  contains  no  oxygen.  On 
this  latter  account  it  is  the  only  substance 
suitable  for  preserving  potassium  and 
the  other  easily  oxidized  metals. 

NAPHTHALIZED  GAS.  Mr.  Lowe, 
of  England,  lias  patented  a  plan  for  pro- 
ducing illuminating  gas,  and  increasing 
the  power  of  coal-gas  by  passing  it 
through  naphtha.  He  charges  the  gas- 
meter  with  naphtha  instead  of  water,  and 
the  gas,  bubbling  through  it,  becomes 
charged  with  the  vapor  of  this  hydro- 
carbon. This  is  the  simplest  way,  but 
gas  companies  objecting,  a  separate  vessel 
was  attached,  filled  with  pieces  of 
sponges,  charged  with  naphtha.  This 
plan  was'found  to  act  equally  well.  Gas 
produces  30  to  50  per  cent,  more  light 
whennaphthalized  than  when  not,  and 
on  this  account  there  is  a  saving  of  20 
per  cent,  in  gas.  It  is  also  more  favor- 
able to  the  human  countenance,  and  to 
the  distinguishing  of  colors.  An  inferior 
gas  can  thus  be  made  equal  to  a  superior 
one ;  and  hydrogen  passed  through 
naphtha  is  highly  luminous.  Carbonic 
oxide,  and  even  carbonic  acid,  can  be 
made  to  burn  when  naphthalized,  and 
common  air  burns  with  a  bright  flame 
when  fully  charged  with  naphtha  vapor. 

NAPHTHALINE  is  a  white  crystal- 
line solid,  obtained  during  the  rectifica- 
tion of  coal-tar  incrusting'the  pipes.  It 
is  also  obtained  in  the  purification  of 
naphtha  (Benzole)  from  coal-oil.  It  has 
a  pungent  aromatic  smell,  and  a  specific 
gravity,  1048.  It  is  a  hydro-carbon,  con- 
taining carbon  94,  and  hydrogen  6,  in 
100  parts.  It  is  one  of  the  most  highly 
carbonized  products. 


NARCOTINE,  one  of  the  constituents 
of  opium,  from  which  it  may  be  obtain- 
ed by  the  following  process  : — Evaporate 
opium  ;  dry  ;  add  muriatic  acid,  or  pyro- 
ligneous  acid,  at  4°  or  5°  ;  press  out  the 
liquor,  add  ammonia,  wash  the  precipi- 
tate with  boiling  alcohol,  at  36°,  cool, 
and  the  narcotine  will  separate,  and  is 
purified  by  bone  black. 

NATRON,  an  impure  carbonate  of 
soda,  originally  brought  from  Egypt.  Near 
Fozzan,  in  New  Africa,  it  is  found,  and 
is  called  Trona.  It  is  also  found  in 
Siberia,  Tartary,  Hindostan,  and  Mexico. 
In  that  republic  there  are  several  natron 
lakes,  to  the  north  of  Zacatecas,  as  well 
as  in  other  localities.  In  Columbia,  48 
miles  from  Merida,  it  5s  dug  up  in  large 
quantity  from  the  bottom  of  the  lakes. 

NAVIGATION  of  the  United  States. 
The  Annual  Kepcrt  on  the  Commerce 
and  Navigation  of  the  United  States,  by 
Senator  Corwin,  presents  some  very  in- 
teresting information  relative  to  the  rapid 
increase  of  our  internal  commerce  espe- 
cially. In  1815  the  tonnage  of  foreign 
shipping  was  854,254  tons ;  of  inland 
navigation  tonnage,  513,813  tons.  In 
1850  the  foreign  tonnage  had  arisen  to 
1,585,711  tons,  and  the  inland  tonnage  to 
1,949,743.  In  1815  the  foreign  tonnage 
exceeded  the  inland  60  per  cent.  Now, 
the  inland  exceeds  the  foreign  25  per 
cent.  The  "  registered  tonnage "  has 
increased  700,000  tons ;  but  the  "enroll- 
ed and  licensed"  has  increased  1,400,000 
tons.  The  whole  increase  from  1820  to 
1850  (a  period  of  thirty  years),  is  175  per 
cent.  Now  the  growth  of  population  in 
that  period  is  180  per  cent.,  proving  the 
growth  of  commerce  and  navigation  to  be 
raster  than  that  of  the  people.  Among 
the  most  obvious  causes  of  this  fact  is  the 
introduction  of  steam  navigation  on  the 
western  rivers.  The  steam  tonnage  on 
all  the  western  rivers  exceeds  800,000 
tons  ;  but  this  had  no  existence  in  1815, 
the  period  of  comparison  in  the  above 
table. 

NEEDLE  MANUFACTURE.  This 
useful  little  article  constitutes  a  large 
business,  giving  employment  to  many 
hundred  operatives.  The  following  is  an 
outline  of  the  various  processes  carried 
out : 

The  best  steel,  reduced  by  a  wire-draw- 
ing machine  to  the  suitable  diameter,  is 
the  material  of  which  needles  are  formed. 
It  is  brought  in  bundles  to  the  needle 
facte ry,  and  carefully  examined.  For 
this  purpose,  the  ends  of  a  few  wires  in 
each  bundle  are  cut  off,  ignited,  and  har- 


390 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[neb 


dened  by  plunging  them  into  cold  water. 
They  are  now  snapped  between  the  fin- 
gers, in  order  to  judge  of  their  quality; 
the  bundles  belonging  to  the  most  brittle 
wires  are  set  aside,  to  be  employed  in 
making  a  peculiar  kind  of  needles. 

After  the  quality  of  the  steel  wire  has 
been  properly  ascertained,  it  is  calibred 
by  means  of  a  gauge,  to  see  if  it  be  equal- 
ly thick  and  round  throughout,  for  which 
Eurpose  merely  some  of  the  coils  of  the 
undies  of  wires  are  tried.  Those  that 
are  too  thick  are  returned  to  the  wire- 
drawer,  or  set  apart  for  another  size  of 
needles. 

The  new  made  coil  is  cut  in  two  points 
diametrically  opposite,  either  by  hand 
shears,  of  which  one  of  the  branches  is 
fixed  in  a  block  by  a  bolt  and  a  nut,  or  by 
means  of  the  mechanical  shears,  the 
crank  of  which  is  moved  by  a  hydraulic 
wheel,  or  steam  power,  and  rises  and  falls 
alternately.  The  extremity  of  this  crank 
enters  into  a  mortise  cut  in  the  arm  of  a 
bent  lever,  and  is  made  fast  to  it  by  a 
bolt.  An  iron  rod,  hinged  at  one  of  its 
extremities  to  the  end  of  the  arm,  and  at 
the  other  to  the  tail  of  the  shears  or  chisel, 
forces  it  to  open  and  shut  alternately. 
The  operative  placed  upon  the  floor, 
presents  the  coil  to  the  action  of  the 
shears,  which  cut  it  into  two  bundles, 
composed  each  of  90  or  100  wires,  up- 
wards of  8  feet  long.  The  chisel  strikes 
21  blows  in  the  minute. 

These  bundles  are  afterwards  cut  with 
the  same  shears  into  the  desired  needle 
lengths,  these  being  regulated  by  the  di- 
ameter. For  this  purpose  the  wires  are 
{>ut  into  a  semi-cylinder  of  the  proper 
ength,  with  their  ends  at  the  bottom  of 
it,  and  are  all  cut  across  by  this  gauge. 
The  wires,  thus  cut,  are  deposited  into  a 
box  placed  alongside  of  the  workman. 

Two  successive  incisions  are  required 
to  cut  100  wires,  the  third  is  lost.  Hence 
the  shears,  striking  21  blows  a  minute, 
cut  in  10  hours  400,000  ends  of  steel  wire, 
which  produce  800,000  needles.  The  cut 
wires  are  bent,  and  have  to  be  made 
straight ;  this  is  done  by  passing  a  flat 
iron  plate  or  rule  with  great  force  once 
or  twice  over  the  cut  bundles. 

The  wires  are  now  taken  to  the  point- 
ing-tools, which  usually  consist  of  about 
80  grindstones  arranged  in  two  rows, 
driven  by  a  water-wheel.  Each  stone  is 
about  18  inches  in  diameter,  and  4  inches 
thick.  As  they  revolve  with  great  velo- 
city, and  are  liable  to  fly  in  pieces,  they 
are  partially  incased  by  iron  plates,  hav- 
ing a  proper  slit  in  them  to  admit  of  the  i 


application  of  the  wires.  The  workman 
seated  in  front  of  the  grindstone,  seizes 
50  or  60  wires  between  the  thumb  and 
forefinger  of  his  right  hand,  and  directs 
one  end  of  the  bundle  to  the  stone.  By 
means  of  a  bit  of  stout  leather  called  a 
thumb-piece,  the  workman  presses  the 
wires,  and  turns  them  about  with  his  fore- 
finger, giving  them  such  a  rotatory  mo- 
tion as  to  make  their  points  conical. 
This  operation,  which  is  called  roughing 
down  is  dry  grinding ;  because,  if  water 
were  made  use  of,  the  points  of  the  need- 
les would  be  rapidly  rusted.  It  has  been 
observed  long  ago,  that  the  silicious  and 
steel  dust  thrown  off  by  the  stones,  was 
injurious  to  the  eyes  and  luugs  of  the 
grinders ;  and  many  methods  have  been 

Proposed  for  preventing  its  bad  effects, 
'he  machine  invented  for  this  purpose 
by  Mr.  Prior,  does  away  with  much  of 
this  evil. 

The  flatted  heads  have  become  harden- 
ed by  the  blow  of  the  hammer ;  when  an- 
nealed by  heating  and  slow  cooling,  they 
are  handed  to  the  piercer.  This  is  com- 
monly a  child,  who,  laying  the  head  upon 
a  block  of  steel,  and  applying  the  point 
of  a  small  punch  to  it,  pierces  the  eye 
with  a  smart  tap  of  a  hammer,  applied 
first  upon  the  one  side,  and  then  exactly 
opposite  upon  the  other. 

Another  child  trims  the  eyes,  which  he 
does  by  laying  the  needle  upon  a  lump 
of  lead,  and  driving  a  proper  punch 
through  its  eye  ;  then  laying  it  sidewise 
upon  a  flat  piece  of  steel,  with  the  punch 
sticking  in  it,  he  gives  it  a  tap  on  each 
side  with  his  hammer,  and  causes  the 
eye  to  take  the  shape  of  the  punch. 
The  operation  of  piercing  and  trimming 
the  eyes  is  performed  by  clever  children 
with  astonishing  rapidity;  who  become 
so  dexterous  as  to  pierce  with  their  punch 
a  human  hair,  and  thread  it  with  another, 
for  the  amusement  of  visitors. 

The  next  operative  makes  the  groove 
at  the  eye,  and  rounds  the  head.  He 
fixes  the  needle  in  pincers,  so  that  the 
eye  corresponds  to  their  flat  side;  he 
then  rests  the  head  of  the  needle  in  an 
angular  groove,  cut  in  a  piece  of  hard 
wood  fixed  in  a  vice,  with  the  eye  in  an 
upright  position.  He  now  forms  the 
groove  with  a  single  stroke  of  a  small  file, 
dexterously  applied,  first  to  the  one  side 
of  the  needle,  and  then  to  the  other.  He 
next  rounds  and  smooths  the  head  with 
a  small  flat  file.  Having  finished,  he 
opens  the  pincers,  throws  the  needle  up- 
on the  bench,  and  puts  another  in  its 
place.    A  still  more  expeditious  method 


nee] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


391 


of  making  the  grooves  and  finishing  the 
heads  has  been  long  used  in  most  En- 
glish factories.  A  small  ram  is  so  mount- 
ed as  to  be  made  to  rise  and  fall  by  a 
pedal  lever,  so  that  the  child  works  the 
tool  with  his  foot;  in  the  same  way  as 
the  heads  of  pins  are  fixed.  A  smali  die 
of  tempered  steel  bears  the  form  of  the 
one  channel  or  groove,  another  similar 
die  that  of  the  other,  both  being  in  re- 
lief; these  being  worked  by  the  lever 
pedal,  finish  the  grooving  of  the  eye  at  a 
single  blow,  by  striking  against  each 
other,  with  the  head  of  the  needle  be- 
tween them. 

The  whole  of  the  needles  thus  prepar- 
ed are  thrown  pell  mell  into  a  sort  of 
drawer  or  box,  in  which  they  are,  by  a 
few  dexterous  jerks  of  the  workman's 
hand,  made  to  arrange  themselves  paral- 
lel to  each  other. 

The  needles  are  now  ready  for  the  tem- 
pering ;  for  which  purpose  they  are 
weighed  out  in  quantities  of  about  30 
pounds,  which  contain  from  250,000  to 
500,000  needles,  and  are  carried  in  boxes 
to  the  temperer.  He  arranges  these  upon 
sheet-iron  plates,  about  10  inches  long, 
and  5  inches  broad,  having  borders  only 
upon  the  two  longer  sides.  These  plates 
are  heated  in  a  proper  furnace  to  bright 
redness  for  the  larger  needles,  and  to  a 
less  intense  degree  for  the  smaller ;  they 
are  taken  out,  and  inverted  smartly  over 
a  cistern  of  water,  so  that  all  the  needles 
may  be  immersed  at  the  same  moment, 
yet  distinct  from  one  another.  The  wa- 
ter being  run  off  from  the  cistern,  the 
needles  are  removed,  and  arranged  by 
agitation  in  a  box,  as  above  described. 
Instead  of  heating  the  needles  in  a  fur- 
nace, some  manufacturers  heat  them  by 
means  of  a  bath  of  melted  lead  in  a  state 
of  ignition. 

After  being  suddenly  plunged  in  the 
cold  water,  they  are  very  hard  and  exces- 
sively brittle.  The  following  mode  of 
tempering:  them  is  practised  at  Neustadt. 
The  needles  are  thrown  into  a  sort  of  fry- 
insr-pau  along  with  a  quantity  of  grease. 
The  pan  being  placed  on  the  fire,  the  fat- 
ty matter  soon  inflames,  and  is  allowed 
to  burn  out ;  the  needles  are  now  found 
to  be  sufficiently  well  tempered.  They 
must,  however,  be  re-adjusted  upon  the 
steel  anvil,  because  many  of  them  get 
twisted  in  the  hardening  and  tempering. 

Polishing  is  the  longest  and  not  the 
least  expensive  process  in  the    needle 
manufacture.    This  is  done  upon  bundles  j 
containing  500,000  needles ;  and  the  same 
machine,  under  the  guidance  of  one  man,  [ 


polishes  from  20  to  30  bundles  at  a  time, 
either  by  water  or  steam  power.  The 
needles  are  rolled  up  in  canvas  along 
with  some  quartzose  sand  interstratified 
between  their  layers,  and  the  mixture  is 
besmeared  with  rape-seed  oil. 

After  polishing,  the  needles  have  to  be 
scoured ;  this  is  done  by  putting  them  in 
a  cask  with  sawdust.  The  cask  turns  on 
a  winch  handle,  and  the  whirling  motion 
rubs  all  the  grease  off  the  surface  of  the 
needles.  The  needles  are  then  taken  out 
and  tvinnowed,  or  have  the  sawdust  blown 
off  them  by  a  winnowing  machine.  They 
are  then  arranged  in  order  by  being  dex- 
terously shaken  in  a  concave  tray,  and 
heaped  up  at  one  end,  so  that  they  can 
be  removed  in  bundles  by  the  hand. 

Sorting  of  the  needles.  This  operation 
is  performed  in  a  dry  upper  chamber, 
kept  free  from  damp  by  proper  stoves. 
Here  all  the  points  are  first  laid  the  same 
way  ;  and  the  needles  are  then  picked 
out  from  each  other  in  the  order  of  their 
polish.  The  sorting  is  effected  with  sur- 
prising facility.  The  workman  places 
2000  or  3000  needles  in  an  iron  ring,  two 
inches  in  diametor,  and  sets  all  their 
heads  in  one  plane;  then,  on  looking 
carefully  at  their  points,  he  easily  recog- 
nizes the  broken  ones  ;  and  by  means  of 
a  small  hook  fixed  in  a  wooden  handle, 
he  lays  hold  of  the  broken  needle  and 
turns  it  out.  These  defective  needles 
pass  into  the  hands  of  another  workman, 
who  points  them  anew  upon  a  grindstone, 
and  they  form  articles  of  inferior  value. 
The  needles  which  have  got  bent  in  the 

?olishing  must  now  be  straightened, 
he  whole  are  finally  arranged  exactly 
according  to  their  lengths  by  the  tact  of 
the  finger  and  thumb  of  the  sorter. 

The  needles  are  divided  into  quantities 
for  packing  in  blue  papers,  by  putting 
into  a  small  balance  the  counterpoise  of 
100  needles,  and  so  measuring  them  with- 
out the  trouble  of  counting. 

Drilled-ej/ed  needles.  Needles  of  the 
above  named  kind  are  made  in  this  coun- 
try, and  by  the  original  inventor,  Mr. 
Win.  Essex,  an  Englishman.  His  factory 
is  in  a  secluded  nook  of  New  Jersey,  near 
Newark.  The  wire  used  is  made  in  En- 
gland expressly  for  the  purpose  —  the 
manufacturers  of  this  country  not  having 
yet  accomplished  the  manufacturing  of 
wire  suited  to  this  purpose.  It  is  first 
cut  into  suitable  lengths,  according  to  the 
size  of  the  needles  to  be  made,  when 
they  ere  straightened  and  pointed  upon 
a  stone  which  is  required  to  be  turned 
with  great  velocity ;  they  are  then  stamp- 


392 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[ntt 


ed,  or  an  impression  made  upon  them 
where  the  eye  is  to  be  made ;  after  which 
the  eye  is  punched  by  means  of  a  press 
invented  for  the  purpose.  The  burr 
made  by  stamping  the  eye  is  filed  smooth, 
after  which  the  hardening  and  tempering 
is  performed,  and  then  they  are  again 
straightened  so  as  to  make  their  shape 
perfect.  By  means  of  machinery,  they 
are  scoured  and  brightened,  and  the  clos- 
ing processes  are,  the  assorting  them  by 
placing  the  heads  and  points  their  re- 
spective ways ;  the  eyes  blued,  or  the 
temper  at  that  point  taken  out,  that  they 
may  not  cut,  and  the  drilling,  counter- 
sinking and  burnishing  the  eyes. 

This  peculiar  branch  of  manufacturing, 
although  not  entirely  new,  is  neverthe- 
less of  somewhat  recent  origin  in  this 
country. 

NEEDLE,  MAGNETICAL.  A  slen- 
der magnetized  bar  of  steel,  which,  when 
suspended  freely  on  a  pivot  or  centre,  ar- 
ranges itself  in  the  direction  of  the  mag- 
netic force  of  the  earth. 

NEEDLE  ORE.  (From  the  acicular 
form  of  its  crystals.)  A  native  sulphuret 
of  bismuth,  copper,  and  lead :  it  occurs 
in  the  gold  mine  of  Schlangenberg,  in 
Siberia. 

NEEDLE  STONE.  A  species  of  aci- 
cular zeolite  found  in  Iceland. 

NICOTINA.  A  poisonous  alkaline 
base,  extracted  from  the  leaves  and  seed 
of  the  Nicotiana  tabacum,  or  common  to- 
bacco. It  derives  its  name  from  Nicot, 
a  Frenchman,  who,  about  1560,  first  sent 
tobacco  into  France.  To  obtain  it,  the 
leaves  are  to  be  digested  in  acidulous 
water,  evaporating  the  infusion  to  a  cer- 
tain point,  adding  lime  to  it,  distilling, 
and  treating  the  product  which  comes 
over  with  ether.  It  is  colorless,  has  an 
acrimonious  taste,  a  pungent  smell,  re- 
mains liquid  at  20°  F.,  mixes  in  all  pro- 
portions with  water,  but  is  in  a  great 
measure  separable  from  it  by  ether, 
which  dissolves  it  abundantly.  It  com- 
bines with  acids,  and  forms  salts  acrid 
and  pungent  like  itself;  the  phosphate, 
oxalate,  and  tartrate  being  crystallizable. 
Nicotine  causes  the  pupils  to  contract. 
A  single  drop  of  it  is  sufficient  to  kill  a 
do».  It  has  acquired  some  notoriety  as 
being  the  substance  selected  by  Count 
Bocarme  to  poison  his  brother-in-law 
with,  and  for  which  he  suffered  on  the 
guillotine  in  1851. 

NITRATE  OF  AMMONIA  is  pre- 
pared by  neutralizing  nitric  acid  with 
carbonate  of  ammonia,  and  crystallizing 
the  solution. 


NITRATE  OF  LEAD  is  made  by  sa- 
turating somewhat  dilute  nitric  acid  with 
oxide  of  lead  (litharge),  evaporating  the 
neutral  solution  till  a  pellicle  appears,  and 
then  exposing  it  in  a  hot  chamber  till  it 
be  converted  into  crystals,  which  are 
sometimes  transparent,  but  generally 
opaque  white  octahedrons.  Their  spec, 
grav.  is  4-068 ;  they  have  a  cooling,  sweet- 
ish, pungent  taste.  They  dissolve  in  7 
parts  of  cold,  and  in  much  less  boiling 
water;  they  fuse  at  a  moderate  elevation 
of  temperature,  emit  oxygen  gas,  and 
pass  into  oxide  of  lead.  Their  consti- 
tuents are  67*3  oxide,  and  32-7  acid. 
Nitrate  of  lead  is  much  employed  in  the 
chrome  yellow  style  of  Calico-Prlnting  ; 
which  see. 

There  are  three  other  compounds  of 
nitric  acid  and  lead  oxide;  viz.,  the  bi- 
basic,  the  tri-basic,  and  the  sex-basic; 
which  contain  respectively  2,  3,  and  6 
atoms  of  base  to  1  of  acid. 

NITRATE  OF  POTASH,  Nitre,  Salt- 
petre. This  salt  occurs  native  as  an 
efflorescence  upon  limestones,  sand- 
stones, marls,  chalk,  and  calctuff;  it 
forms  a  saline  crust  in  caverns,  as  also 
upon  the  surface  of  the  ground  in  certain 

E laces,  especially  where  animal  matters 
ave  been  decomposed.     Such  caverns 
exist  in  Germany  near  Homburg  (Burk- 
ardush) ;    in   Apulia  upon  the  Adriatic 
sea  (Pnlo  di  Mofetta>,  in  France ;  in  the 
East  Indies ;  in  Ceylon,  where  22  nitri- 
ferous  caverns  are  mentioned ;  in  North 
America,  at  Crooked  river,  Tennessee, 
Kentucky,  and  upon  the  Missouri ;    in 
Brazil,  Teneriffe,  and  Africa.    Nitre  oc- 
curs as  an  efflorescence  upon  the  ground 
in  Arragon,  Hungary,   Podolia,    Sicily, 
Egypt,  Persia,   Bengal,   China,   Arabia, 
North    America,    and    South    America. 
j  Several  plants  contain  saltpetre ;  parti- 
|  cularly  borage,  dill,  tobacco,  sunflowers, 
;  stalks  of  maize,  beet-root,  bugloss,  parie- 
taria,  &c.     It  has  not  hitherto  been  found 
j  in  animal  substances. 

This  salt  consists  of  54  nitric  acid  +  48 
potassa;  its  equivalent,  therefore,  is  102. 
|  It  is  spontaneously  generated  in  the  soil, 
and  crystallizes  upon  its  surface  in  seve- 
!  ral  parts  of  the  world,  especially  in  In- 
dia, whence  nearly  the  whole  of  the  nitre 
used  in  Britain  is  derived.     It  has  occa- 
sionally been  produced  artificially  in  nitre 
beds,  formed  of  a  mixture  of  calcareous 
|  soil  with  animal  matter ;  in  these,  nitrate 
j  of  lime  is  slowly  formed,  which  is  ex- 
tracted by  lixiviation,  and  carbonate  of 
potash  added  to  the  solution,  which,  by 
■  double  decomposition,  gives  rise  to  the 


•] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


393 


formation  of  nitrate  of  potash  and  car- 
bonate of  lime :  the  latter  is  precipitated : 
the  former  remains  in  solution,  and  is 
obtained  in  crystals  by  evaporation.  Ni- 
tre crystallizes  in  six-sided  prisms,  solu- 
ble in  seven  parts  of  cold  water,  and  in 
less  than  its  weight  of  boiling  water.  It 
has  a  cooling  saline  taste,  and  is  anhy- 
drous. At  616°  it  fuses,  and  at  a  red  heat 
is  decomposed.  Its  great  use  is  in  the 
manufacture  of  gunpowder,  and  in  the 
production  of  nitric  acid.  It  is  also  em- 
ployed in  the  preservation  of  meat. 

Dr.  Ure,  in  his  valuable  Dictionary  of 
Arts,  discusses  this  interesting  question 
— How  is  nitre  annually  reproduced  upon 
the  surface  of  limestones,  and  the 
ground,  after  it  has  been  removed  by 
washing?  It  has  been  said,  in  reply, 
that  as  secondary  limestones  contain  re- 
mains of  animal  matters,  the  oxygen  of 
the  atmosphere,  absorbed  in  virtue  of 
the  porous  structure,  will  combine  with 
their  azote  to  form  nitric  acid  ;  whence 
nitrate  of  lime  will  result.  Where  potash 
is  present  in  the  ground,  a  nitrate  of  that 
base  will  be  next  formed.  The  genera- 
tion of  nitre  is  in  all  cases  limited  to  a 
very  small  distance  from  the  surface  of 
porous  stones  ;  no  further,  indeed,  than 
where  atmospherical  air  and  moisture 
can  penetrate  ;  and  none  is  ever  pro- 
duced upon  the  surface  of  compact 
stones,  such  as  marble  and  quartz,  or  of 
argillaceous  minerals.  Dr.  John  Davy 
and  M.  Longchamp  have  advanced  an 
opinion,  that  the  presence  of  azotized 
matter  is  not  necessary  for  the  generation 
of  nitric  acid  or  nitrous  salts,  but  that  the 
oxygen  and  azote  of  the  atmosphere, 
when  condensed  by  capillarity,  will  com- 
bine in  such  proportions  as  to  form  nitric 
acid,  through  the  agency  of  moisture  and 
of  neutralizing  bases,  such  as  lime,  mag- 
nesia, potash,  or  soda.  They  conceive 
that  as  spongy  platina  serves  to  combine 
oxygen  and  hydrogen  into  water,  or  the 
vapor  of  alcohol  and  oxygen  into  acetic 
acid,  and  as  the  peroxyde,  as  well  as  the 
hydrate  of  iron  and  argillaceous  minerals, 
serve  to  generate  ammonia  from  the 
oxygen  of  the  air  and  the  hydrogen  of 
water;  in  like  manner,  porous  lime- 
stones, through  the  agency  of  water, 
operate  upon  the  constituents  of  the  at- 
mosphere to  produce  nitric  acid,  without 
the  presence  of  animal  matter.  This 
opinion  may  certainly  be  maintained ;  for 
in  India,  Spain,  and  several  other  coun- 
tries at  a  distance  from  all  habitations, 
immense  quantities  of  saltpetre  are  re- 
produced in  soils  which  have  been  wash- 


ed the  year  before.  But,  on  the  other  hand, 
it  is  known  that  the  production  of  this 
salt  may  be  greatly  facilitated  and  in- 
creased by  the  admixture  of  animal  offals 
with  calcareous  earths. 

It  is  now  known,  that  ammonia  in  tho 
nascent  state,  or  just  in  the  moment  of  be- 
ing generated  by  decomposition  of  ani- 
mal matters,  is  converted  into  nitric  acid, 
if  a  stronger  base,  such  as  lime  or  potash, 
be  present:  the  oxygen  of  the  air  is 
brought  into  play,  and,  uniting  with  the 
ammonia  just  formed,  alters  that  sub- 
stance into  nitric  acid  and  water ;  8  equi- 
valents of  oxygen  uniting  with  1  equi- 
valent of  ammonia,  to  form  1  equivalent 
of  nitric  acid  and  3  equivalents  of  water. 
The  acid  thus  produced  then  seizes  on 
the  potash,  and  becomes  neutralized. 
This  explains  why  animal  matter,  and 
stirring  the  compost,  hastens  nitrifica- 
tion. 

Nitre  is  applied  to  many  purposes  : — 1, 
to  the  manufacture  of  gunpowder;  2,  to 
that  of  sulphuric  acid ;  3,  to  that  of  ni- 
tric acid,  though  nitrate  of  soda  or  cubio 
nitre  has  lately  superseded  this  use  of  it 
to  a  considerable  extent;  4,  to  that  of 
flint-glass ;  5,  it  is  used  in  medicine ;  6Z 
for  many  chemical  and  pharmaceutical 
preparations  ;  7,  for  procuring,  by  defla- 
gration with  charcoal  or  cream  of  tartar, 
pure  carbonate  of  potash,  as  also  black 
and  white  fluxes ;  8,  for  mixing  with  salt 
in  curing  butcher  meat;  9,  in  some 
countries  for  sprinkling  in  solution  upon 
grain,  to  preserve  it  from  insects  ;  10,  for 
making  fireworks. 

Nitre  has  sometimes  been  mistaken  for 
Glauber's  salt ;  and,  when  taken  in  the 
quantity  of  half  an  ounce  or  an  ounce,  it 
acts  as  a  powerful  poison.  In  such  cases 
the  stomach  should  be  evacuated  as  ra- 
pidly as  possible,  and  the  symptoms  of 
spasm  relieved  by  opiates.  In  doses  of  5 
to  15  grains  it  is  diuretic  and  diaphoretic. 

NEPHELINE.  A  mineral  from  Som- 
ma,  near  Vesuvius,  and  Capo  di  Bovo, 
near  Rome  ;  in  nitric  acid  its  transparent 
fragments  become  cloudy.  It  is  a  double 
selicate  of  alumina  and  soda.  It  is  also 
known  by  the  name  of  sommite. 

NEPHEITE.  A  hard,  tough  mineral, 
composed  chiefly  of  silica,  with  lime, 
soda,  and  potash.  It  is  difficult  to  break, 
cut,  or  polish  ;  it  is  slightly  translucent, 
and  usually  of  a  greenish  color.  It  is  oc- 
casionally manufactured  into  sword  and 
knife  handles,  and  has  even  been  cut  in- 
to the  form  of  a  chain,  which,  from  its 
extreme  toughness,  is  not  easily  broken. 
Little  plates  of  it  were  formerly  suspend- 

17* 


394 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[nio 


ed  from  the  neck  for  the  cure  of  nephritic 
complaints,  whence  its  name.  The  Chi- 
nese are  celebrated  for  articles  composed 
of  it.  Its  essential  components  are  silica, 
alumina,  and  magnesia. 

NEROLI.  Essential  oil  of  orange 
flowers.  It  is  procured  by  distillation 
with  water,  in  the  same  way  as  the  other 
essential  oils. 

NESTS,  ESCULENT.  A  species  of 
nests  built  by  swallows  peculiar  to  the 
Indian  islands,  and  very  much  esteemed 
in  China  and  other  parts  of  the  world. 
These  nests  resemble  in  form  those  of 
other  swallows;  they  are  formed  of  a 
viscid  substance,  and  in  external  appear- 
ance, as  well  as  consistence,  are  not  un- 
like fibrate  ill-concocted  isinglass.  Escu- 
lent nests  are  principally  found  in  Java, 
in  caverns  usually  situated  on  the  sea- 
coast.  Nothing  satisfactory  is  known  as 
to  the  substance  of  which  these  nests  are 
composed. 

NET,  or  NEAT.  In  commerce,  some- 
thing pure  and  unadulterated  with  any 
foreign  mixture.  Thus,  wines  are  said. 
to  be  net  when  not  falsified ;  and  coffee, 
rice,  &c,  to  be  so,  when  the  filth  and 
ordures  are  separated  from  them.  The 
word  net  is  also  used  for  what  remains 
after  the  tare  has  been  taken  out  of  any 
merchandise — i.  e.,  when  it  is  weighed 
clear  of  all  package.  Net  Produce  (Ital. 
netto  proceduto)  is  used  in  mercantile 
language  to  express  what  any  commodity 
has  yielded,  after  all  tare  and  charges 
have  been  deducted. 

NET  is  a  textile  fabric  of  knotted 
meshes  for  catching  fish,  and  other  pur- 
poses. Each  mesh  should  be  so  secured 
as  to  be  incapable  of  enlargement  or 
diminution.  The  French  Government 
offered,  in  1802,  a  prize  of  10,000  francs 
to  the  person  who  should  invent  a  ma- 
chine for  making  nets  upon  automatic 
principles,  and  adjudged  it  to  M.  Buron, 
who  presented  his  mechanical  invention 
to  the  Conservatoire  des  Arts  et  Metiers. 
It  does  not  appear,  however,  that  this 
machine  has  accomplished  the  object  in 
view ;  for  no  establishment  was  ever 
mounted  to  carrv  it  into  execution.  Nets 
are  usuallv  made  by  the  fishermen  and 
their  families  during  periods  of  leisure. 

NEUTRALIZATION.  In  chemistry, 
the  combination  of  an  acid  and  alkali  in 
such  proportions  that  the  peculiar  pro- 
perties of  each  are  rendered  inert. 

NEUTRAL  SALTS.    This  term  is  ap- 
plied to  all  salts  which  contain  an  acid  i 
saturated  with  an  alkali,  an  earth,  or  a  ! 
metal.      Bergmann  confined  it  to  salts  i 


containing  alkali;  and  he  called  the 
earthy  and  metallic  salts,  middle  salts. 
It  Avas  most  usual  to  call  the  alkaline 
salts  with  an  acid  neutral,  and  to  distin- 
guish the  others  by  the  respective  ap- 
pellations, earthy  and  metallic;  but  the 
term  neutral  is  now  applied  to  those  salts 
which  contain  1  equivalent  of  acid  and  1 
equivalent  of  base. 

NICARAGUA  WOOD  is  obtained 
from  the  cozsalpinia  echinata,  a  tree  grow- 
ing in  Mexico.  With  solution  of  tin  as  a 
mordant,  it  gives  a  bright  but  fugitive 
red.  It  is  inferior  in  dyeing  power  to 
Brazil  wood. 

NICKEL  is  a  silver-like  metal,  sp.  gr. 
8-9.  It  is  magnetic,  and  is  greedy  of 
oxygen,  forming  gray  protoxide  and  black 
peroxide.  Heat  will  not  oxidate  it  be- 
cause it  drives  off  oxygen  as  fast  as  it 
fixes  ;  but  the  oxides  are  formed  by  solu- 
tion in  nitric  acid,  precipitating  by  pot- 
ash, and  then  heating  to  redness.  It  is 
usually  associated  with  cobalt:  it  is  al- 
ways present  in  meteoric  stones  :  in  the 
Harz  Mountains  it  is  associated  with 
copper,  as  hupfemickel  ore;  with  arsenic 
and  iron,  as  arsenic-nickel.  It  also  exists 
as  an  oxide,  a  sulphuret,  and  an  arseniate, 
in  gneiss,  mica  slate,  and  sienite. 

The  chief  of  these  ores,  and  that  from 
which  most  of  the  nickel  of  Conemera  is 
obtained,  is  the  copper-colored  ore  above 
described  as  hupfemickel — nickel  being  a 
term  of  detraction  used  by  the  German 
miners,  who  expected  from  the  color  of 
the  ore  to  find  that  it  contained  copper. 
The  salifiable  oxide  of  nickel  consists  of 
30  nickel +  8  oxygen.  Its  salts  are  most- 
ly of  a  grass-green  color,  and  the  amrao- 
niacal  solution  of  its  oxide  is  deep  blue, 
like  that  of  copper.  Ferrocyanate  of  pot- 
assa  precipitates  it  of  a  white  or  very  pale 
green  color. 

Since  the  manufacture  of  German  sil- 
ver, or  argentine,  became  an  object  of 
commercial  importance,  the  extraction  of 
nickel  has  been  undertaken  upon  a  con- 
siderable scale.  The  cobalt  ores  are  its 
most  fruitful  sources,  and  they  are  now 
treated  by  the  method  of  Wohler  to 
effect  the  separation  of  the  two  metals. 
The  arsenic  is  expelled  by  roasting  the 
powdered  speiss  first  by  itself,  next  with 
the  addition  of  charcoal  powder,  till  the 
garlic  smell  be  no  longer  perceived.  The 
residuum  is  to  be  mixed  with  three  parts 
of  sulphur  and  fine  of  potash,  melted  in  a 
crucible  with  a  gentle  neat,  and  the  pro- 
duct being  edulcorated  with  water,  leaves 
a  powder  of  metallic  lustre,  which  is  a 
.sulphuret  of  nickel  free  from  arsenic; 


nit] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


395 


while  the  arsenic  associated  with  the  sul- 
phur, and  combined  with  the  resulting 
sulphuret  of  potassium,  remains  dis- 
solved. Should  any  arsenic  still  be  found 
in  the  sulphuret,  as  may  happen  if  the 
first  roasting  heat  was  too  great,  the 
above  process  must  be  repeated.  The 
sulphuret  must  be  finally  washed,  dis- 
solved in  concentrated  sulphuric  acid, 
with  the  addition  of  a  little  nitric;  the 
metal  must  be  precipitated  by  a  carbon- 
ated alkali,  and  the  carbonate  reduced 
with  charcoal. 

In  operating  upon  kupfernickel,  or 
speiss,  in  which  nickel  predominates,  | 
after  the  arsenic,  iron,  and  copper  have 
been  separated,  ammonia  is  to  be  digest- 
ed upon  the  mixed  oxides  of  cobalt  and 
nickel,  which  will  dissolve  them  into  a 
blue  liquor.  This  being  diluted  with 
distilled  water  deprived  of  its  air  by  boil- 
ing, is  to  be  decomposed  by  caustic  pot- 
ash till  the  blue  color  disappears,  wnen 
the  whole  is  to  be  put  into  a  bottle  tightly 
stoppered,  and  set  aside  to  settle.  The 
preen  precipitate  of  oxide  of  nickel, 
which  slowly  forms,  being  freed  by  de- 
cantation  from  the  supernatant  red  solu- 
tion of  oxide  of  cobalt,  is  to  be  edulco- 
rated and  reduced  to  the  metallic  state  in 
a  crucible  containing  crown  glass.  Pure 
nickel,  in  the  form  of  a  metallic  powder, 
is  readily  obtained  by  exposing  its  oxal- 
ate to  moderate  ignition. 

Since  the  application  of  Liebig's  cyan- 
ide of  potassium  to  the  separation  of  me- 
tals in  a  mixed  solution,  the  foregoing 
mode  is  generally  given  up  for  the  use  of 
the  cyanide.  A  solution  of  cyanide  of 
potassium  is  added  to  the  mixed  oxide, 
and  heat  applied.  The  cyanide  must  be 
quite  free  from  cyanate.  The  solution 
is  boiled  to  drive  off  excess  of  acid.  Per- 
oxide of  mercury  is  then  added  to  the 
solution,  when  the  nickel  is  precipitated, 
partly  as  oxide,  partly  as  pure  metal :  it 
is  then  collected,  dried,  and  calcined,  at 
a  red  heat,  leaves  the  oxide  perfectly  free 
from  cobalt. 

NITRATE  OF  SILVER  is  prepared 
by  saturating  pure  nitric  acid  of  specific 
grav.  1-25  with  pure  silver,  evaporating 
the  solution,  and  crystallizing  the  nitrate". 
When  the  drained  crystals  are  fused  in  a 

f)latina  capsule,  and  cast  into  slender  cy- 
inders  in  silver  moulds,  they  constitute 
the  lunar  caustic  of  the  surgeon.  This 
should  be  white,  and  unchangeable  by  \ 
liffht.  It  is  deliquescent  in  moist  air.  i 
The  crystals  are  colorless,  transparent  4 
and  6  sided  tables  ;  they  possess  a  bitter, 
acrid,    and    most    disagreeable    metallic 


taste:  they  dissolve  in  their  own  weight 
of  cold,  and  in  much  less  of  hot  water ; 
are  soluble  in  four  parts  of  boiling  alcohol, 
but  not  in  nitric  acid  ;  they  deflagrate  on 
redhot  coals,  like  all  the  nitrates  ;  and  de- 
tonate with  phosphorus  when  the  two  are 
struck  together  upon  an  anvil.  They 
consist  of  68-2  of  oxide,  and  31-8  of  acid. 
Nitrate  of  silver,  when  swallowed,  is  a 
very  energetic  poison  ;  but  it  may  be 
readily  counteracted,  by  the  administra- 
tion of  a  dose  of  sea-salt,  which  converts 
the  corrosive  nitrate  into  the  inert  chlo- 
ride of  silver.  Animal  matter,  immersed 
in  a  weak  solution  of  neutral  nitrate  of 
silver,  will  keep  unchanged  for  any 
length  of  time  ;  and  so  will  polished  iron 
or  steel.  Nitrate  of  silver  is  such  a  deli- 
cate reagent  of  hydrochloric  or  muriatic 
acid,  as  to  show  by  a  sensible  cloud,  the 
presence  of  one  113  millionth  part  of  it, 
or  one  7  millionth  part  of  sea-salt  in  dis- 
tilled water.  It  is  much  used  under  the 
name  -of  indelible  ink,  for  writing  upon 
linen  with  a  pen  ;  for  which  purpose  one 
drachm  of  the  fused  salt  should  be  dis- 
solved in  three  quarters  of  an  ounce  of 
water,  adding  to  the  solution  as  much 
water  of  ammonia  as  will  redissolve  the 

f>recipitated  oxide,  with  sap-green  to  co- 
or  it,  and  gum- water  to  make  the  volume 
amount  to  one  ounce.  Traces  written 
with  this  liquid  should  be  first  heated  be- 
fore a  fire  to  expel  the  excess  of  ammonia, 
and  then  exposed  to  the  sun-beam  to 
blacken.  Another  mode  of  using  nitrate 
of  silver  as  an  indelible  ink,  is  to  imbue 
the  linen  first  with  solution  of  carbonate 
of  soda,  to  dry  the  spot,  and  write  upon 
it  with  a  solution  of  nitrate  of  silver, 
thickened  with  gum,  and  tinted  with  sap- 
green. 

NITRATE  OF  SODA,  Culiml  Nitre, 
occurs  under  the  nitre  upon  the  lands  in 
Spain,  India,  Chili,  ana  remarkably  in 
Peru,  in  the  districts  of  Atacama  andTa- 
racapa,  where  it  forms  a  bed  several  feet 
thick.  It  appears  in  several  places  upon 
the  surface,  and  extends  over  a  space  of 
more  than  40  leagues,  approaching  near 
to  the  frontiers  of'Chili.  It  is  sometimes 
efflorescent,  sometimes  crystallized,  but 
oftcner  confusedly  mixed  with  clay  and 
sand.  This  immensely  valuable  deposit 
is  only  three  days'  journey  from  the  port 
of  Conception  in  Chili,  and  from  Iquiqui, 
another  harbor  situated  in  the  southern 
part  of  Peru. 

Nitrate  of  soda  may  be  artificially  pre- 
pared by  neutralizing  nitric  acid  with  so- 
da, and  crystallizing  the  solution.  It 
crystallizes  in  rhomboids,  has  a  cooling, 
-'■-_;--■'- 


396 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[NIT 


pungent,  bitterish  taste,  less  disagreeable 
than  nitre  ;  it  becomes  moist  in  the  air ; 
dissolves  in  3  parts  of  water  at  60°  F.,  in 
less  than  1  part  of  boiling  water  ;  defla- 
grates more  slowly  than  nitre,  and  with  j 
an  orange  yellow-flame.    It  consists,  in  j 
its  dry  state,  of  36-6  soda  63-4  nitric  acid  ;  j 
but  its  crystals  contain  one  prime  equiva-  | 
lent  of  water;  hence  they  are  composed  j 
of,  acid  56-84,  base  33-68,  water  9-47. 

It  is  susceptible  of  the  same  applica- 
tions  as  nitre,  with  the  exception  of  mak-  ! 
ing  gunpowder ;  for   which    it    is    not  ] 
adapted,* on  account  of  its  deliquescent  j 
property. 

Its  chief  uses  are  in  the  manufacture  of  | 
nitric  acid,  and  as  a  manure.    It  has  a  re- 
markable effect  in  increasing  the  growth 
of  leaf  in  plants,  and  is  only  second,  to  the 
ammoniacal  manures  in  power. 

NITRATE  OF  STRONTIA.  This  salt 
is  usually  prepared  from  the  sulphuret  of 
strontium,  obtained  by  decomposing  sul- 
phate of  strontia  with  charcoal,  by  strong 
ignition  of  the  mixed  powders  in  a  cruci- 
ble. This  sulphuret  being  treated  with 
water,  and  the  solution  being  filtered,  is 
to  be  neutralized  with  nitric  acid,  as  in- 
dicated by  the  test  of  turmeric  paper ; 
care  being  taken  to  avoid  breathing  the 
noxious  sulphureted  hydrogen  gas,  which 
is  copiously  disengaged.  The  solution, 
which  requires  to  be  properly  evaporated 
and  set  aside,  affords  colorless  crystals,  of 
a  slender  octohedral  form.  It  effloresces 
when  heated,  and  gives  a  fine  powder, 
which,  when  mixed  with  charcoal  and 
chlorate  of  potash,  affords  the  brilliant  red 
light  of  the  theatres. 

NITRIC  ACID  exists,  in  combination 
with  the  bases,  potash,  soda,  lime,  mag- 
nesia, in  both  the  mineral  and  vegetable 
kingdoms.  This  acid  is  never  found  in- 
sulated. It  was  distilled  from  saltpetre 
so  long  ago  as  the  13th  century,  by  ignit- 
ing that  salt,  mixed  with  copperas  or  clay, 
in  a  retort.  Nitric  acid  is  generated 
when  a  mixture  of  oxygen  and  nitrogen 
gases,  confined  over  water  or  an  alkaline 
solution,  has  a  series  of  electrical  explo- 
sions passed  through  it. 

This  acid  is  a  compound  of  1  atom  or 
equivalent  of  nitrogen  =  14,  and  5  of  oxy- 
gen (8  X  5)  =  40  ;  hence  its  equivalent  in 
the  dry  or  anhydrous  state,  as  it  exists, 
for  instance,  in  nitre,  is  14  ■+■  40  =  54.  As 
it  usually  occurs  in  the  liquid  state,  it  is 
a  compound  of  1  equivalent  of  dry  acid, 
54,  and  2  of  water  (9  X  2),  18  ;  hence  the 
equivalent  of  the  liquid  acid  is  72.  It  is 
commonly  known  in  commerce  under  the 
of  aqua  fortis,  and  is  prepared  by 


distilling  a  mixture  of  sulphuric  acid  and 
nitre.  It  is  commonly  yellow,  or  even 
deep  orange  colored ;  but  it  may  be  de 
prived  of  nitric  oxide,  which  occasions 
this  color,  by  heat,  and  is  then  colorless. 
It  is  intensely  corrosive  and  sour,  fumes 
when  exposed  to  air,  and  has  a  specific 
gravity  of  1-50  when  in  its  utmost  state 
of  concentration.  It  boils  at  248°,  and 
freezes  at  — 50°.  It  is  a  most  powerfully 
oxidizing  agent,  and  is  decomposed  with 
more  or  less  rapidity  by  almost  all  the 
metals. 

The  salts  which  it  forms  are  called  ni- 
trates ;  they  are  all  soluble  in  water ;  they 
are  decomposed  by  heat,  and,  when  mix- 
ed and  gently  heated  with  sulphuric  acid, 
they  evolve  nitric  or  nitrous  acid. 

On  the  small  scale  nitric  acid  may  be 
made  by  heating  together  nitrate  of  pot- 
ash and  diluted,  oil  of  vitrol  in  atomic  pro- 
portions :  a  receiver  or  flask  should  be 
attached  to  the  tube  of  the  retort  and 
kept  cool  by  immersion  in  water.  Cold 
should  also  be  applied  to  the  neck  of  the 
retort.  When  the  mixture  begins  to  boil, 
red  fumes  come  off,  which  cease  after 
awhile,  and  reappear  at  the  close  of  the 
process.  To  obtain  a  pure  acid  it  is  ne- 
cessary to  change  the  receivers  and  reject 
the  first  and  last  portions  of  the  distilla- 
tion, which  contain  the  nitrous  acid  fumes, 
chlorine,  and  perhaps,  sulphuric  acid. 
That  which  distills  over,  when  pure,  is 
the  concentrated  acid  having  a  density  of 
1-492. 

On  the  large  scale,  iron-retorts  are  used 
similar  to  them,  in  which  hydrochloric  acid 
is  obtained. 

Nitrate  of  soda  is  now  generally  used 
in  place  of  nitre,  as  affording  more  acid 
and  being  a  cheaper  salt.  The  acid  ob- 
tained thus  contains  a  nitrate  of  iron,  and 
requires  redistillation  before  it  can  be 
gotten  rid  of.  Nitric  acid,  of  a  density 
of  1-47,  may  be  had,  colorless  ;  but  when 
farther  concentrated,  it  is  partially  de- 
composed ;  whereby  some  nitrons  acid  is 
produced,  which  gives  it  a  straw-yellow 
tinge.  At  this  strength  it  exhales  white 
or  orange  fumes,  which  have  a  peculiar, 
though  not  very  disagreeable  smell ;  and 
even  when  largely  diluted  with  water,  it 
tastes  extremely  sour.  The  greatest  den- 
sity at  which  it  can  be  obtained  is  1-51  or 
perhaps  1-52,  at  60°  F.,  in  which  state,  or 
even  when  much  weaker,  it  powerfully 
corrodes  all  animal,  vegetable,  and  most 
metallic  bodies.  When  slightly  diluted  it 
is  applied,  with  many  precautions,  to  silk 
and  woollen  stuffs,  to  stain  them  of  a 
bright  yellow  hue. 


'J 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


397 


In  the  dry  state,  as  it  exists  in  nitre, 
this  acid  consists  of  26-15  parts  by  weight 
of  azote,  and  73-85  of  oxygen ;  or  of  2 
volumes  of  the  first  gas,  and  5  volumes 
of  the  second. 

When  of  specific  gravity  1-5,  it  boils  at 
about  210°  Fahr. ;  of  1-45,  it  boils  at  about 
240°  ;  of  1-42,  it  boils  at  253°  ;  and  of  1-40, 
at  246°  F.  If  an  acid  stronger  than  1-420 
be  distilled  in  a  retort,  it  gradually  be- 
comes weaker  ;  and  if  weaker  than  1-42, 
it  gradually  becomes  stronger,  till  it  as- 
sumes that  standard  density.  Acid  of 
specific  gravity  1.485  has  no  more  action 
upon  some  metals,  as  tin,  than  water  has, 
though  when  either  stronger  or  weaker 
it  oxidizes  it  rapidly,  and  evolves  fumes 
of  nitrous  gas  with  explosive  violence. 
Acid  of  1-420  consists  ot  1  atom  of  dry 
acid,  :uid  4  of  water;  acid  of  1*485,  of  1 
atom  of  dry  acid,  and  2  of  water  ;  the  lat- 
ter compound  possesses  a  stable  equili- 
brium as  to  chemical  agency  ;  the  former 
as  to  calorific.  Acid  of  specific  gravity 
1-334,  consisting  of  7  atoms  of  water,  and 

1  of  dry  acid,  resists  the  decomposing 
agency  of  light.  Nitric  acid  acts  with 
great  energy  upon  most  combustible  sub- 
stances, simple  or  compound,  giving  up 
oxygen  to  them,  and  resolving  itself  into 
nitrous  gas,  or  even  azote.  Such  is  the 
result  of  its  action  upon  hvdrogen,  phos- 
phorus, sulphur,  charcoal,  sugar,  gum, 
starch,  silver,  mercury,  copper,  iron,  tin, 
and  most  other  metals. 

NITKIC  OXIDE,  or  NITROUS  GAS. 
This  gas  was  discovered  by  Hales,  and 
more  accurately  studied  by  Priestley.  It 
is  obtained  duri&g  the  action  of  nitric 
acid  diluted  with  about  two  parts  of  water 
upon  metallic  copper  :  it  is  copiously 
evolved,  and  may  oe  collected  over  water. 
One  hundred  cubical  inches  of  this  gas 
weigh  between  32  and  33  grains  ;  its  den- 
sity, therefore,  compared  with  air,  is  1037. 
It  Is  at  once  easily  recognized  by  forming 
orange-colored  fumes  whenever  it  escapes 
into  the  air  or  comes  into  contact  with  ox- 
ygen, so  that  this  gas  and  oxygen  are  ex- 
cellent tests  of  each  other's  presence.  It 
consists  of  equal  volumes  of  nitrogen  and 
oxygen,  or  of  1  equivalent  of  nitrogen  and 

2  of  oxygen  ;  hence  it  is  termed  a  binox- 
ide  or  deutoxide  of  nitrogen.  The  re- 
spective weight  of  its  components,  there- 
fore, are  14  nitrogen  +  16  oxygen,  and  the 
equivalent  of  the  gas  is  30. 

NITRITES.  Salts  of  the  nitrous  acid  ; 
thus  nitrite  of  potassa  is  a  compound  of 
1  atom  of  nitrous  acid  and  1  atom  of  po- 
tassa, &c. 

NITROGEN.    A  simple  gaseous  body 


which  forms  a  constituent  part  of  nitnc 
acid,  and  which,  being  unrespirable,  has 
also  been  termed  azote.  It  was  identified 
as  a  peculiar  gas  by  Dr.  Rutherford  in 
1774,  and  shown  to  be  one  of  the  compo- 
nents of  atmospheric  air  by  Lavoisier  in 
1774.  It  is  generally  obtained  by  burning 
a  piece  of  phosphorus  in  a  jar  full  of  air 
inverted  over  water.  The  phosphorus 
during  its  combustion  combines  with  the 
oxygen  of  the  air  to  form  phosphoric 
acid,  which  is  dissolved  by  the  water,  and 
the  remaining  element  of  the  air,  namely, 
the  nitrogen,  remains.  Nitrogen  is  a 
colorless,  inodorous,  and  tasteless  gas, 
not  absorbed  by  water,  and  having  no  ac- 
tion on  vegetable  colors.  It  extinguishes 
all  burning  bodies,  and  is  itself  uninflam- 
mable. It  is  a  little  lighter  than  atmos- 
pheric air,  100  cubic  inches  weighing 
30'16  grains.  Its  equivalent  is  14,  and  it 
combines  with  oxygen  in  5  proportions, 
giving  rise  to  the  following  compounds  : 

By  volume.  By  weight.  Equiv.  Symbols. 

1.  Nitrous  oxide  100+  50=14+  8=22=«+  c. 

2.  Nitrous  oxide  100+100=14+16=30=n+2<- 

3.  Hyponitrous 

acid  100+150=14+24=38=7i+8o 

4.  Nitrous  acid     100+200=14+32=46=71+40. 

5.  Nitric  acid       100+250=14+40=54=7t+5o 

N1TRO-MURIATIC  ACID,  Aqua  reaia, 
is  the  compound  menstruum  invented  by 
the  alchemists  for  dissolving  gold.  If 
strong  nitric  acid,  orange-colored  by  sa- 
turation with  nitrous  gas  (deutoxide  of 
azote),  be  mixed  with  the  strongest  liquid 
muriatic  acid,  no  other  effect  is  produced 
than  might  be  expected  from  the  action 
of  nitrous  acid  of  the  same  strength  upon 
an  equal  quantity  of  water;  nor  has  the 
mixed  acid  so  formed  any  power  of  acting 
upon  gold  or  platina.  But  if  colorless 
aquafortis  and  ordinary  muriatic  acid  be 
mixed  together,  the  mixture  immediately 
becomes  yellow,  and  acquires  the  power 
of  dissolving  these  two  noble  metals. 
When  gently  heated,  pure  chlorine  gas 
rises  from  it,  and  its  color  becomes  deep- 
er ;  when  further  heated,  chlorine  still 
rises,  but  now  mixed  with  nitrous  acid 
gas.  If  the  process  has  been  very  long 
continued,  till  the  color  becomes  very- 
dark,  no  more  chlorine  can  be  procured, 
and  the  liquor  has  lost  the  power  of  dis- 
solving gold.  It  then  consists  of  nitrous 
and  muriatic  acids.  It  appears,  therefore, 
that  aqua  regia  owes  its  peculiar  proper- 
ties to  the  mutual  decomposition  of  the 
nitric  and  muriatic  acids  :  and  that  water, 
chlorine,  and  nitrous  acia  gas  are  the  re- 
sults of  that  reaction.     Aqua  regia  does 


898 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[not 


not,  strictly  :ipeaking,  oxidize  gold  and 
platinum ;  it  causes  merely  their  combi- 
nation with  chlorine.  It  may  be  compos- 
ed of  very  different  proportions  of  the 
two  acids ;  the  nitric  being  commonly  of 
specific  gravity  1-34;  the  muriatic,  of 
specific  gravity  1-18  or  1*19.  Sometimes 
3  parts,  and  at  others  6  parts  of  the  mu- 
riatic acid  are  mixed  with  1  of  nitric.  It 
may  also  be  made  by  adding  nitre  to  mu- 
riatic acid. 

NITRO-NAPTHALASE.  A  compound 
resulting  from  the  action  of  nitric  acid  on 
napthalin  :  a  modification  of  it  has  been 
termed  nitro-napthalese. 

NITRO-SACCHARIC  ACID.  By  the 
action  of  sulphuric  acid  en  gelatine  a  pe- 
culiar saccharine  matter  is  formed,  which 
combines  with  nitric  acid,  and  forms  a 
crystallized  acid  designated  as  above. 

NITRO-SULPHURIC  ACID.  An  acid 
resulting  from  the  mixture  of  one  part  of 
nitre  with  eight  or  ten  parts  of  sulphuric 
acid.  It  was  originally  proposed  by  Mr. 
Keir  as  a  useful  agent  for  separating  the 
silver  from  the  copper  of  old  plated  goods. 
At  the  temperature  of  about  200°  it  dis- 
solves silver,  while  it  scarcely  acts  upon 
copper  or  lead,  unless  diluted,  orat  high- 
er temperatures. 

NITROUS  ACID.  When  two  volumes 
of  nitric  oxide  and  one  of  oxygen  are 
mingled  in  an  exhausted  glass  globe  they 
form  a  dense  orange-colored  vapor,  which 
may  be  liquefied  Dy  cold,  and  which  is 
nitrous  acid.  Its  elements  are  so  con- 
densed that  1  volume  of  nitrogen  and  2 
of  oxygen  form  1  volume  of  nitrous  acid 
vapor,  the  specific  gravity  of  which  is 
3-17.  The  presence  of  this  vapor  renders 
nitric  acid  red  and  fuming,  in  which  state 
it  is  commonly  termed  nitrous  acid. 

NITROUS  OXIDE.  Protoxide  of  ni- 
trogen ;  a  gas  obtained  by  heating  nitrate 
of  ammonia,  which  salt  is  thus  resolved 
into  nitrous  oxide  gas  and  water.  When 
nitrous  oxide  is  respired,  it  produces  ef- 
fects somewhat  similar  to  those  of  intoxi- 
cation ;  hence  it  has  been  called  laughing 
gas. 

NITROUS  ETHER,  or  Sweet  Spirit  of 
Nitre,  is  made  by  putting  three  pints  of 
alcohol  into  a  bottle  placed  in  cold  water, 
and  adding  by  degrees  one  pint  of  nitrous 
acid.  Let  it  stand  for  seven  days,  and 
then  distil  it  at  a  moderate  heat  into  a 
cooled  receiver.  It  is  diuretic  and  anti- 
febrile, taken  in  half  a  tea-spoonful  or  tea- 
spoonful  in  a  glass  of  water,  or  barley- 
water. 

NOOTH'S  APPARATUS.  This  is 
used   to  impregnate  water  with  gases. 


Three  glass  vessels  are  connected  over 
one  another.  The  lower  contains  the 
gas-making  materials,  marble  and  muri- 
atic acid,  with  an  orifice  closed  to  admit 
more.  The  second  is  filled  with  water, 
and  a  valve  and  the  gas,  rising  into  it, 
soon  fill  both  vessels  with  impregnated 
water.  The  gas  passes  through  the  se- 
cond vessel,  where  it  is  washed,  and  col- 
lects in  the  upper  one.  Woolfe,  Pepys, 
Knight,  and  Hamilton  have  improvea  it. 

NOPAL.  The  Cactus  Opuntia,  This 
is  the  tree  on  which  the  Cochineal  insect 
lives.     It  grows  in  Mexico. 

NOTES,  in  printing  are — shouldtr  notes: 
these  are  at  the  top  of  the  page  in  the 
outer  margin,  and  contain  the  book, 
chapter  or  date,  or  both  of  them ;  side 
notes  or  marginal  notes,  which  give  an 
abstract  of  the  text,  as  in  acts  of  parlia- 
ment ;  or  parallel  passages,  and  different 
readings,  as  in  the  Bible*,  and  bottom 
notes,  or  foot  notes,  which  are  placed  at 
the  bottom  of  the  page,  and  generally 
contain  commentaries  and  annotations. 

NOTE.  Bank  note,  manufacture  of.  A 
block  of  thick  plate  steel  is  softened  on 
the  upper  side;  the  device  is  engraved 
on  this  softened  surface  ;  the  block  is 
hardened  by  a  careful  process  after  the 
engraving ;  the  device  is  transferred  from 
the  hardened  block  to  the  convex  sur- 
face of  a  small  soft  steel  roller,  by  in- 
tense pressure;  the  roller  is  hardened, 
and  the  device  is  transferred  from  it  to 
any  number  of  softened  steel  plates ; 
these  plates  are  hardened  after  the  trans- 
fer, and  are  then  in  a  state  to  be  printed 
from.  By  this  beautiful  train  of  opera- 
tions, one  originally  engraved  block  is 
made  to  suffice  for  an  almost  endless 
number  of  engravings.  The  mode  in 
which  the  writing,  the  emblems,  and  the 
ornaments  are  combined  in  a  bank-note, 
is  so  planned  as  to  render  forgery  diffi- 
cult. The  numbering  is  a  remarkable 
process,  as  now  performed.  Four  wheels, 
each  divided  by  ten  notches,  leaving  a 
face  between  each  pair,  engraved  with 
consecutive  numbers  from  1  to  0,  are 
placed  upon  a  shaft :  a  portion  of  their 
breadth  being  turned  down  about  one 
half  of  their  depth,  having  a  boss  or  collar 
between  every  two.  Upon  these  bosses, 
and  filling  up  the  spaces,  rest  latches; 
and  over  each  wheel  is  a  pall,  the  width 
of  the  first  being  equal  to  that  of  the  unit 
wheel,  and  the  breadth  of  the  others 
equalling  that  of  the  wheel  and  latch. 
The  palls  are  driven  by  a  crank  ;  by  each 
revolution  of  which  the  first  wheel  is 
moved  through  a  space  equal  to  one- 


nut] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


399 


tenth  of  its  entire  circumference,  bring- 
ing regularly  forward  the  numbers  from  1 
to  0.  When  the  figure  0  is  reached,  the 
latch  of  the  second  wheel  is  depressed, 
and  the  wheel  moves  forward  one  divi- 
sion, making  the  tens.  The  same  process 
is  repeated  with  regard  to  the  other 
wheels,  and  thus  any  amount  of  num- 
bers can  be  registered,  by  simply  increas- 
ing the  number  of  wheels  in  proportion. 
Machines  of  this  kind  are  extensively 
adopted  in  the  Bank  of  England ;  with,  of 
course,  an  inking  apparatus  to  apply  to  the 
types.  A  patent  was  taken  out  in  1844  for 
a  mode  of  printing  bank-notes  intended  to 
obviate  the  liability  to  forgery.  The  sur- 
face is  covered  with  two  designs,  one 
geometrically  regular,  and  the  other  very 
irregular  ;  the  two  designs  are  engraved, 
on  different  plates,  and  are  printed  with 
different  inks,  the  one  with  visible  and 
the  other  with  invisible  ink.  Both  of 
the  inks  are  delible,  or  removable  by 
chemical  means ;  and  the  usual  engrav- 
ing of  a  bank  note  is  printed  on  paper  so 
prepared.  The  rationale  of  the  sugges- 
tion is  this — that  whatever  means  a  for- 
ger might  take  to  alter,  by  chemical 
agency,  the  letters  or  figures,  or  to  trans- 
fer them  by  lithographic  or  anastic  pro- 
cesses, the  state  of  the  paper  would  be- 
tray him;  for  he  would  remove  some 
parts  of  the  design  in  the  one  case,  and 
fail  to  transfer  in  the  other. 

NOVACULITE.  The  stone  of  which 
hones  are  made  for  sharpening  razors.  It 
is  of  a  slaty  structure,  and  owes  its  quali- 
ty of  giving  an  edge  to  the  metal  to  the 
fine  silicious  particles  which  it  contains. 

NUT  OF  A  SCKEW.  In  mechan- 
ics, a  piece  of  wood,  iron,  or  other 
metal,  pierced  cylindrically,  wherein  is 
cut  a  spiral  groove,  adapted  to  an  exter- 
nal cylindrical  spiral  cut  on  a  bolt.  Its 
use  is  to  screw  two  bodies  together,  a 
head  being  placed  on  one  end  of  the  bolt 
to  counteract  the  action  of  the  nut.  Two 
bodies  are  thus  held  together  by  com- 
pression, the  bolt  between  the  head  and 
the  nut  being  a  tie. 

NUTS.  The  fruit  of  different  species 
of  Coryli  or  hazels.  The  kernels  have  a 
mild  farinaceous  oily  taste,  agreeable  to 
most  palates  ;  a  kind  of  chocolate  has  been 
prepared  from  them,  and  they  have  j 
sometimes  been  made  into  bread.  The 
expressed  oil  of  hazel  nuts  is  little  infe- 
rior to  that  of  almonds.  Besides  those 
raised  at  home,  nuts  are  imported  from 
different  parts  of  France,  Portugal,  and 
Spain,  but  chiefly  from  the  latter.  The 
Spanish    nuts    in    highest    estimation, 


though  Sold  by  the  name  cf  Barcelona 
nuts,  are  not  shipped  from  thence,  but 
from  Tarragona,  whence  the  average  an- 
nual export  is  estimated  at  from  25,000  to 
30,000  bags,  four  to  the  ton. 

NUTTALITE.  A  mineral  associated 
witli  calcspar,  from  Bolton,  in  Massachu- 
setts :  it  occurs  in  prismatic  crystals,  and 
appears,  from  Dr.  Thomeon's  analysis, 
to  be  an  alumino-silicate  of  lime,  potash, 
and  iron. 

NUTMEG-TKEE.  A  native  of  the  Mo- 
lucca, or  Spice  Islands,  principally  con- 
fined to  that  group  denominated  the 
Islands  of  Banda,  lying  in  lat.  4°  30' 
south.  It  bears  both  blossom  and  fruit, 
at  all  seasons  of  the  year,  and  assists 
with  other  aromatic  trees  and  shrubs,  to 
form  that  atmosphere  of  fragrance,  in  the 
upper  regions  of  the  air,  in  which  the 
natives  believe  the  birds  of  paradise  per- 
petually float. 

While  the  Dutch  remained  possessors 
of  the  Spice  Islands,  the  quantity  of 
nutmegs  and  mace  exported  from  their 
nutmeg-grounds,  circumscribed  as  they 
were,  was  enormous ;  250,000  lbs.  annu- 
ally used  to  be  vended  in  Europe,  and 
nearly  half  that  amount  in  the  East  In- 
dies. Of  mace,  the  average  has  been 
90,000  lbs  sold  in  Europe,  and  10,000  lbs. 
in  the  East  Indies. 

When  the  Islands  were  taken  by  the 
British,  in  1796,  the  importations  of  the 
East  India  Company  into  England  alone, 
in  the  two  years  following  the  capture, 
were,  of  nutmegs,  129,732  lbs.,  and  of 
mace  286,000  lbs.  When  the  crops  of 
spice  were  superabundant,  and  the  price 
likely  to  be  reduced,  the  Dutch  destroyed 
immense  quantities  of  the  fruit.  A  Hol- 
lander informed  Sir  Wm.  Temple,  that, 
at  one  time,  he  saw  three  piles  of  nut- 
megs burnt,  each  of  which  was  larger 
than  a  church  could  hold. 

In  the  Moluccas,  the  gathering  of  the 
fruit  takes  place  at  three  periods,  in  July  ' 
or  August,  when  the  nutmegs  are  most 
abundant,  but  the  mace  thinner  than  in 
smaller  fruits,  gathered  in  November  ; 
the  third  harvest  is  in  March  or  April, 
when  the  nuts,  as  well  as  the  mace,  are 
in  the  greatest  perfection.  The  outer 
pulpy  coat  is  removed,  and.  afterwards^ 
the  mace,  with  a  knife.    The  nuts  are 

E  laced  over  a  slow  fire,  when  the  shell 
ecomes  very  brittle,  and  the  seeds,  or 
nutmegs,  drop  out ;  these  are  then  soaked 
in  sea- water,  and  impregnated  with  lime, 
a  process  which  answers  the  double  pur- 
pose of  securing  the  seeds  from  the 
attack  of  insects,  and  of  destroying  then 


460 


CYCT.OPEOTA  OF  THE  USEFUL  ARTS. 


[oak 


vegetating  property.  It  further  prevents 
the  volatilization  of  the  aroma.  The  mace 
is  simply  dried  in  the  sun,  and  then 
sprinkled  with  salt-water,  after  which  it 
is  fit  for  exportation. 

The  color,  when  fresh,  is  a  brilliant 
scarlet.  When  dry,  it  becomes  much 
more  horny,  of  a  yellow-brown  color,  and 
very  brittle.  The  shell  very  hard,  rugged 
dark-biown,  glossy,  about  half  a  line 
thick,  pale  and  smooth  within.  This 
immediately  envelopes  the  seed,  or  nut- 
meg, whieh  is  of  an  oval  elliptical  form, 
pale  brown,  quite  smooth,  when  first  de- 
prived of  its  shell,  but  soon  becomes 
shrivelled,  so  as  to  have  irregular,  verti- 
cal lines,  or  furrows  on  its  surface.  Its 
outside  very  thin ;  its  inner  substance  or 
albumen  is  firm,  but  fleshy,  whitish,  but 
bo  traversed  with  red-brown  veins,  which 
abound  in  oil,  as  to  appear  beautifully 
marbled.  Near  the  base  of  the  albumen, 
and  imbedded  in  a  cavity  in  its  substance, 
is  situated  the  embryo,  which  is  large, 
fleshy,  yellowish-white,  rounded  below, 
where  is  the  radicle ;  its  cotyledons,  of 
two  large,  somewhat  foliaceous.  plicate 
lobes,  in  the  centre  of  which  is  seen  the 
plumule. 

NUTRIA.  The  commercial  name  for 
the  skins  of  My(rpotamua  Bonariensis, 
the  Coypou  of  Molina,  and  the  Quoiya  of 
D'Azara.  In  France  the  skins  were, 
and  perhaps  still  are,  sold  under  the 
name  of  racoonda  ;  but  in  England  they 
are  imported  as  nuti*ia  skins — deriving 
their  appellation,  most  probably,  from 
some  supposed  similarity  of  the  animal 
which  produces  them,  in  appearance  and 
habits,  to  the  otter,  the  Spanish  name 
for  which  is  nutria.  Indeed,  Molina 
speaks  of  the  coypou  as  a  species  of  water- 
rat  of  the  size  and  color  ot  the  otter. 

In  England,  nutria  fur  is  largely  used  in 
the  hat  manufacture,  and  has  become, 
within  the  last  15  or  20  years,  an  article  of 
very  considerable  commercial  importance. 
The  imports  fluctuate  considerably.  In 
1823,  they  amounted  to  1,570,103  skins ; 
but  they  have  not,  in  any  other  year,  been 
much  more  than  half  that  number.  In 
1826,  they  were  only  60,871.  In  1837  and 
1838,  the  imports  were,  at  an  average, 
858,280  skins  a  year.  Those  entered  for 
home  consumption  pay  a  duty  of  lid.  a 
skin.  They  are  principally  brought  from 
the  Rio  de  la  Plata.  Nutria  skins  are 
very  extensively  used  on  the  continent. 
Geoffrey  mentions  that,  in  certain  years, 
a  single  French  furrier  (M.  Bechem)  has 
received  from  15,000  to  20,000  skins. 

Like  the  beaver,  the  coypou  is  fur- 


nished with  two  kinds  of  fur — viz.,  the 
long  ruddy  hair,  which  gives  the  tone  of 
color,  and  the  brownish  ash-colored  fur 
at  its  base,  which,  like  the  down  of  the 
beaver,  is  of  much  importance  in  hat 
making,  and  the  cause  of  the  animal's 
commercial  value. 

The  habits  of  the  coypou  are  much  like 
those  of  most  of  the  other  aquatic  Rodent 
animals.  Its  principal  food,  in  a  state  of 
nature,  is  vegetable.  It  affects  the  neigh- 
borhood of  water,  swims  perfectly  well, 
and  burrows  in  the  ground.  The  female 
brings  forth  from  five  to  seven  at  a  time, 
and  the  young  always  accompany  her. 

The  coypou  is  easily  domesticated,  and 
its  manners  in  captivity  are  very  mild. 

OAK.  The  general  nan.c  of  a  well 
known  hard-wooded  forest  i.tje,  much 
cultivated  for  the  purposes  of  timber,  par- 
ticulary  in  ship-building,  and  in  other 
cases  where  much  exposure  to  the  weath- 
er is  required.  There  are  several  varie- 
ties of  this  valuable  tree ;  but  the  com- 
mon English  oak  ( Quercus  robur)  claims 
precedence  of  every  other  of  European 
growth.  The  knotty  oak  of  England,  the 
"unwedgeable  and  gnarled  oak,"  as  Shak- 
speare  called  it,  when  cut  down  at  a  pro- 
per age  (from  50  to  70  years),  is  the  best 
timber  known.  Some  timber  is  harder, 
some  more  difficult  to  rend,  and  some 
less  capable  of  being  broken  across ;  but 
none  contains  all  the  three  qualities  in  so 
great  and  equal  proportions  ;  and  thus, 
for  at  once  supporting  a  weight,  resisting 
a  strain,  and  not  splintering  by  a  cannon- 
shot,  the  timber  of  the  oak  is  superior  to 
every  other. 

A  fine  oak  is  one  of  the  most  pictur- 
esque of  trees :  it  conveys  to  the  mind 
associations  of  strength  and  duration 
which  are  very  impressive.  The  oak 
stands  up  against  the  blast,  and  does  not 
take,  like  other  trees,  a  twisted  form  from 
the  action  of  the  winds.  Except  the  ce- 
dar of  Lebanon,  no  tree  is  so  remarkable 
for  the  stoutness  of  its  limbs ;  they  do 
not  exactly  spring  from  the  trunk,  but 
divide  from  it;  and  thus  it  is  sometimes 
difficult  to  know  which  is  stem  and  which 
is  branch.  The  twisted  branches  of  the 
oak,  too,  add  greatly  to  its  beauty ;  and 
the  horizontal  direction  of  its  boughs, 
spreading  over  a  large  surface,  completes 
the  idea  of  its  sovereignty  over  all  the 
trees  of  the  forest. 

The  oak  is  raised  from  acorns,  sown 
either  where  the  oak  is  to  stand,  or  in  a 
nursery  whence  the  young  trees  are 
transplanted. 

The  color  of  oak  wood  is  a  fine  brown, 


oak] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


401 


and  is  familiar  to  every  one :  it  is  of  dif- 
ferent shades  ;  that  inclined  to  red  is  the 
most  inferior  kind  of  wood.  The  larger 
transverse  septa  are  in  general  very  dis- 
tinct, producing  beautiful  flowers  when 
cut  obliquely.  Where  the  septa  are  small 
and  not  very  distinct,  the  wood  is  much 
the  strongest.  The  texture  is  alternate- 
ly compact  and  porous  ;  the  compact  part 
of  the  annual  ring  being  of  the  darkest 
colors,  and  in  irregular  dots,  surrounded 
by  open  pores,  producing  beautiful  dark 
veins  in  some  kinds,  particularly  pollard 
oaks.  Oak  timber  has  a  particular  smell, 
and  the  taste  is  slightly  astringent.  It 
contains  gallic  acid,  and  is  blackened  by 
contact  with  iron  when  it  is  damp.  The 
young  wood  of  English  oak  is  very  tough, 
often  cross-grained,  and  difficult  to  work. 
Foreign  wood,  and  that  of  old  trees,  is 
more  brittle  and  workable.  Oak  warps 
and  twists  much  in  drying ;  and,  in  sea- 
soning, shrinks  about  l-32d  of  its  width. 

Oak  of  a  good  quality  is  more  durable 
than  any  other  wood  that  attains  a  like 
size.  Vitruvius  says  it  is  of  eternal  dura- 
tion when  driven  into  the  earth  :  it  is  ex- 
tremely durable  in  water ;  and  in  a  dry 
state  it  has  been  known  to  last  nearly 
1000  years.  The  more  compact  it  is,  and 
the  smaller  the  pores  are,  the  longer  it  will 
last ;  but  the  open,  porous,  and  foxy-col- 
ored oak,  which  grows  in  Lincolnshire  and 
some  other  places,  is  not  near  so  durable. 

Besides  the  common  British  oak  (Quer- 
cu8  robur),  the  sessile-fruited  bay-oak 
{Quercw  sessilijlora)  is  pretty  abundant 
in  several  parts  of  England,  particularly 
in  the  north.  The  wood  of  this  species 
is  said  by  Tredgold  to  be  darker,  heavier, 
harder,  and  more  elastic  than  the  com- 
mon oak ;  tough,  and  difficult  to  work ; 
and  very  subject  to  warp  and  split  in  sea- 
soning. Mr.  Tredgold  seems  disposed  to 
regard  this  species  as  superior  to  the  com- 
mon oak  for  shipbuilding.  But  other,  and 
also  very  high  authorities,  are  opposed  to 
him  on  this  point;  and,  on  the  whole,  we 
should  think  that  it  is  sufficiently  well 
established  that  for  all  the  great  practical 
purposes  to  which  oak  timber  is  applied, 
and  especially  for  shipbuilding,  the  wood 
of  the  common  oak  deserves  to  be  pre- 
ferred to  every  other  species. 

The  oak  is  among  the  most  useful  pro- 
ductions of  temperate  climates,  with  the 
exception  of  a  lew  on  the  mountainous 
parts  of  the  equatorial  regions.  More 
than  eighty  species  are  known,  of  which 
one  half  inhabit  North  America,  either 
within  the  territory  of  the  United  States, 
or  on  the  mountains  of  Mexico.    The  i 


white  oak  ( Q.  alba)  is  one  of  the  most 
valuable.  It  extends  from  lat  46°  to  Flor- 
ida, and  from  the  Atlantic  to  a  little  west 
of  the  Mississippi.  It  attains  the  height 
of  seventy  or  eighty  feet,  with  a  trunk 
six  or  seven  in  diameter.  It  is  usual, 
after  stripping  the  oak  of  its  bark,  to 
leave  it  standing  for  three  or  four  years 
before  it  is  cut  for  use.  This  species,  and 
the  stillata,  are  the  species  which  furnish 
staves  for  casks,  of  which  the  consump- 
tion is  immense.  White  oak  timber  is 
imported  in  immense  quantities,  from  the 
ports  of  the  Northern  and  Middle  States ; 
and  that  brought  from  Quebec  is  procur- 
ed chiefly  on  the  borders  of  Lake  Cham- 
plain,  in  the  states  of  New  York  and  Ver- 
mont. It  is  also  used  for  making  the 
keels  and  knees  of  ships.  The  Q.  macro- 
carpa  is  remarkable  for  the  large  size  of 
the  leaves  and  acorns,  but  the  wood  is  of 
little  value.  The  Q.  lyrata  is  exclusively 
confined  to  wet  swamps.  The  acorns  are 
nearly  covered  by  the  cups.  The  timber 
is  large  and  highly  esteemed. 

The  live  oak  (Q.  virem)  is  a  tree  of  the 
very  first  importance.  It  is  found  grow- 
ing along  the  Atlantic  shores  of  the  Unit- 
ed States  for  1600  miles,  from  Norfolk 
southwards.  The  leaves  are  evergreen, 
coriaceous,  and  entire.  It  does  not  usu- 
ally attain  greater  height  than  forty  or 
forty-five  feet,  with  a  trunk  one  or  two  in 
diameter,  but  the  wide  and  branching 
summit  furnishes  knees  of  vessels.  The 
wood  is  used  for  the  naves  and  felloes 
of  heavy  wheels,  for  which  purposes  it  is 
far  superior  to  the  white  oak,  as  well  as 
for  screws  and  the  cogs  of  mill-wheels. 
In  the  Southern  States  it  is  used  for  the 
frame-work  of  ships,  and  is  looked  on  to 
be  as  durable  as  any  European  variety. 
The  bark,  too,  is  excellent  for  tanning. 
The  black  or  quercitron  oak  ( Q.  tinctoria) 
is  a  large  tree,  found  throughout  the 
United  States  south  of  latitude  43°,  and 
abundant  in  the  Middle  States.  It  is  re- 
cognized by  the  yellow  stain  which  it 
gives  to  the  saliva  on  being  chewed.  The 
wood  is  reddish  and  coarse-grained,  and 
is  frequently  substituted  for  white  oak  in 
building.  It  furnishes  a  large  proportion 
of  the  red  oak  staves  which  arc  exported 
to  the  West  Indies,  and  the  bark  is  ex- 
tensively employed  in  tanning.  From 
the  cellular  integument  quercitron  is  ob- 
tained— an  article  extensively  employed 
in  dyeing  wool,  silk,  and  paper-hangings, 
and  which  forms  an  important  article  of 
export  from  Philadelphia.  The  cork  oak 
(Q.  suber)  furnishes  the  cork  of  com- 
merce,  which  substance  is    the    outer, 


402 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[oat 


thick,  fungous  covering  of  the  bark,  and 
is  detached,  at  intervals  of  ten  or  twelve 
years,  for  as. many  as  twelve  or  fifteen 
times,  but  after  the  fifth  or  sixth  the 
quality  degenerates.  If  not  removed  af- 
ter a  certain  period,  it  splits  and  falls  off, 
and  is  replaced  by  a  new  growth  beneath. 
In  some  countries,  where  cork  is  abun- 
dant, the  inhabitants  use  it  for  lining  or 
covering  their  houses.  When  burnt  in  , 
close  vessels,  a  black  powder  is  obtained,  I 
known  under  the  name  of  Spanish  black. 
The  corkoak  is  cultivated  in  Spain,  Por- 
tugal, and  the  south  of  France.  It  is  best 
adapted  to  a  dry,  sandy,  mountainous 
soil,  and  is  never  found  in  limestone  dis- 
tricts. 

To  ascertain  the  strength  of  New  For- 
est oak  (English),  a  seasoned  stick  of  tim- 
ber was  selected  in  April.  From  about 
midway  between  the  centre  and  circum- 
ference of  the  tree,  and  beginning  at  about 
four  feet  from  the  ground  end,  a  piece  of 
very  good  and  perfectly  sound  timber  was 
cut,  and  reduced  to  the  dimensions  of  five 
inches  square,  and  eleven  feet  long.  It 
was  laid  across  two  uprights ;  and  a  rough 
scale-like  platform  to  contain  the  weight, 
formed  of  a  very  large  plank,  was  sus- 
pended from  the  centre  by  a  strong  tim- 
ber chain.  Upon  this  platform,  piece 
after  piece  was  laid  of  hard  Purbeck  stone, 
until  it  became  evident  that  there  was 
sufficient  to  effect  the  fracture,  and  in  a 
few  seconds  the  whole  fell  to  the  ground. 
The  stones  employed  were  then  weighed, 
and  the  weight  of  the  platform  and  chain 
being  added,  it  was  found  that  the  aggre- 
gate weight  by  which  the  object  had  been 
obtained,  was  9061  pounds,  or  4  tons,  3 
quarters,  and  17  pounds. 

Oak  bark,  in  the  inner  cortical  of  young 
trees,  contains  77  of  111  of  the  tannin 
principle.  The  cellular,  or  middle,  only 
19  of  43,  and  the  external  part  scarcely 
any  tannin.  In  spring,  the  tannin  is 
more  than  in  winter.     See  Tan. 

OAKUM  is  the  substance  into  which 
old  ropes  are  reduced  when  they  are  un- 
twisted, loosened,  and  drawn  asunder. 
It  is  principally  used  in  calking  the  seams, 
tree-nails,  and  bends  of  a  ship,  for  stop- 
ping or  preventing  leaks. 

OAR.  In  nautical  affairs,  a  long  piece 
of  timber,  flat  at  one  end,  and  round  or 
square  at  the  otherj  by  which  a  boat, 
barge,  or  galley,  &c,  is  propelled  through 
the  water.  The  flat  part  dipped  into  the 
water  is  called  the  blade  ;  the  other  end 
is  the  loom,  which  terminates  in  the 
handle.  The  fulcrum  of  the  oar  is  the 
hole  in  the  gunwale  called  the  rowlock, 


or  between  two  pins  called  thole  pins,  or 
one  thole  pin  with  a  loose  strap  lor  con- 
fining the  oar.  There  are  various  nauti- 
cal phrases  contingent  upon  this  term,  a 
few  of  which  may  not,  perhaps,  be  out  of 

Jilace  here.  To  boat  the  oars,  signifies  to 
ay  them  in  from  rowing ;  to  feather  the 
oar,  to  hold  the  blade  horizontally,  so  as 
not  to  catch  the  wind ;  to  lie  on  the  oars, 
to  suspend  rowing  for  any  interval ;  this 
is  also  the  salute  given  to  persons  of  dis- 
tinction in  passing ;  to  ship  aud  unship 
the  oars,  respectively  to  fix  and  throw 
them  out  of  the  rowlocks. 

OATS.  The  avena  sativa.  Natural 
family  gramincos.  A  gramineous  plant 
characterised  by  a  loose  compound  equal 
panicle  and  two-flowered  spikelet.  The 
oat  is  very  extensively  cultivated  in  most 
of  the  northern  countries  of  Europe  as  a 
bread  corn.  It  has  long  occupied  the 
same  place  in  Scotland  that  rye  occupies 
in  Germany  and  the  potato  in  Ireland. 
In  England  it  is  chiefly  used  in  the  feed- 
ing of  horses ;  but  there,  also,  it  is  used 
to  a  considerable  extent  as  food  for  man, 
particularly  in  the  northern  counties. 
There  are  leading  varieties  of  the  com- 
mon oat  cultivated  in  England — black; 
fray,  dun-brown,  or  red;  and  white, 
he  first  two  varieties  being  compara- 
tively hardy,  may  be  raised  on  very  in- 
ferior soils,  and  in  situations  unsuitable 
for  the  other.  The  black  is  now,  how- 
ever, hardly  known  in  England  ;  but  it  is 
still  cultivated  to  a  considerable  extent  in 
some  parts  of  the  Highlands  of  Scotland, 
and  in  the  Western  Islands.  The  dun  or 
red  oat  is  principally  confined  to  the 
moors  of  Cheshire,  Derbyshire,  and  Staf- 
fordshire. White  oats  are,  speaking  gen- 
erally, less  hardy  than  either  of  the  other 
varieties,  and  require  a  better  soil,  but 
they  are  also  earlier,  heavier,  and  yield  a 
greater  quanity  of  meal.  There  are  num- 
berless, and  some  widely  different  sub- 
varieties  of  the  white  oat.  That  which 
is  called  the  potato  oat  has  long  enjoyed 
the  highest  reputation  in  England,  and 
is  almost  the  only  variety  that  is  at  pres- 
ent raised  on  good  land  in  most  parts  of 
England  and  the  south  of  Scotland.  The 
produce  of  oats  varies  very  greatly. 
When  the  giound  is  foul  or  exhausted, 
not  more  than  20  bushels  an  acre  are  ob- 
tained :  but  in  a  rich  soil  well  managed, 
and  in  favorable  years,  60,  70,  and  some- 
times even  80  bushels  and  upwards  have 
been  reaped,  weighing  from  35  lbs.  to 
45  lbs.  a  bushel,  and  yielding  7  lbs.  meal 
for  14  lbs.  oats;  but  the  proportion  of 
meal  increases  as  the  oats  become  heavier. 


OBj] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


403 


In  this  country,  on  average  soils,  the 
yield  is  from  40  to  50  bushels,  but  on 
rich  land,  it  goes  up  to  120  bushels.  It  is 
the  common  white  oat  which  is  most 
raised  here.  In  Western  New- York  the 
black  oat  is  preferred,  and  the  Egyptian 
oat  south  of  Tennessee.  The  latter  rarely 
gives  20  bushels  of  ripe  grain.  It  is  by 
far  the  best  food  for  working  cattle  or 
horses.  There  is  a  very  good  analysis  of 
oats,  made  by  Professor  Norton,  of  New 
Haven.  In  nutritious  properties  it  stands 
next  to  wheat,  and  above  rye,  barley,  and 
rice. 

OBJECT-GLASS  (of  a  refracting  tele- 
scope or  microscope).  The  lens  which 
first  receives  the  rays  of  light  coming  di- 
rectly from  the  object,  and  collects  them 
into  a  focus,  where  they  form  an  image 
which  is  viewed  through  the  eye-glass. 

The  excellence  of  an  object-glass  de- 
pends on  the  distinctness  of  the  image 
which  it  forms.  On  account  of  the  un- 
equal refrangibility  of  the  rays  of  light,  it 
is  necessary,  in  order  to  procure  a  distinct 
image,  to  employ  an  achromatic  combin- 
ation of  lenses,  formed  of  substances  hav- 
ing different  dispersive  powers,  and  of 
such  figures  that  the  aberration  of  the 
one  may  be  corrected  by  that  of  the  other. 
The  substances  chiefly  used  are  crown- 
glass  and  flint-glass  ;  the  dispersive 
powers  of  which  are  respectively  as  3  to 
5.  By  combining  a  convex  lens  of  crown- 
glass  with  a  concave  lens  of  flint-glass, 
having  their  focal  distances  in  that  pro- 
portion, an  image  would  be  formed  free 
from  color,  but  it  would  not  be  free  from 
aberration.  The  determination  of  the 
form  of  the  compound  lens  which  shall 
give  the  least  possible  aberration  for  par- 
allel rays  is  a  problem  which  admits  of 
exact  calculation.  The  following  are  the 
dimensions  found  by  Sir  John  Herschel 
for  an  object-glass  of  thirty  inches  focal 
length,  the  convex  lens  of  which  was 
of  common  glass,  the  outside  towards  the 
object,  and  the  concave  lens  of  flint-glass 
on  the  side  next  the  eye  :  radius  ot  the 
exterior  surface  of  the  crown  lens,  20-0364 
inches ;  radius  of  the  exterior  surface  of 
the  flint  lens,  41-1687  inches ;  radii  of  the  ' 
interior  surfaces,  10-1604  and  10-1613 
When  the  lenses  have  the  forms  here  in- 
dicated, the  focal  lengths  of  each,  separ- 
ately, are  in  the  direct  ratio  of  their  dis- 
persive powers  ;  and  the  two  inside  sur- 
faces have  so  nearly  the  same  curvature 
that  they  may  be  ground  on  the  same 
tool,  and  united  by  a  cement  to  prevent 
the  loss  of  light  at  the  two  surfaces. 

Such  are  the  forms  indicated  by  theory ; 


but  the  practical  difficulties  of  forming  a 
good  achromatic  object-glass,  for  a  tele- 
scope of  large  size,  are  so  great  that  it 
often  costs  more  than  all  the  rest  of  the 
instrument.  This,  however,  principally 
arises  from  the  extreme  difficulty  of  pro- 
curing disks  of  flint-glass,  above  a  cer- 
tain size,  sufficiently  free  from  veins  and 
imperfections  as  to  be  fit  for  the  purpose. 
No  object-glasses  of  a  larger  size  than 
seven  inches  diameter  have  been  made  of 
glass  manufactured  in  England  ;  and,  not- 
withstanding the  success  of  Fraunhofcr 
at  Munich,  and  of  Guinaud  in  Switzer- 
land, the  procuring  of  flint-glass  fit  for 
object-lenses  of  a  larger  size  seems  to  be 
still,  in  a  considerable  degree,  a  matter  of 
accident.  Fraunhofer  executed  a  telescope 
for  the  Eussian  observatory  at  Dorput, 
having  an  object-glass  of  9  inches  diame- 
ter. Another  was  prepared  by  him  for 
the  King  of  Bavaria,  ot  12  inches  diame- 
ter. The  object-glass  of  Sir  James 
South's  large  telescope  at  the  Campden 
Hill  observatory  is  nearly  13  inches  in 
diameter,  and  was  executed  in  Paris  of 
glass  manufactured  by  Guinaud. 

In  the  fine  telescopes  formerly  con- 
structed by  Dollond,  the  object-glasses 
were  composed  of  three  lenses,  the  two 
exterior  ones,  being  of  crown-glass,  and 
convex,  and  the  interior  of  flint  and  con- 
cave. This  combination  gives  a  more 
perfect  correction  of  the  spherical  abrera- 
tion ;  but  the  advantage  is  more  than 
balanced  by  the  greater  complexity  of 
their  construction,  the  risk  of  imperfect 
centering,  and  the  loss  of  light  at  the  six 
surfaces.  They  have  accordingly  been 
disused. 

Various  attempts  have  been  made  to  dis- 
pense with  the  concave  flint  lens,  by  the 
substitution  of  some  other  refractive  sub- 
stance. Dr.  Blair  found  that  the  disper- 
sion of  crown-glass  was  corrected  by  a 
fluid  lens,  composed  of  a  mixture  of  solu- 
tions of  ammoniacal  and  mercurial  salts. 
He  succeeded  in  making  object-glasses  in 
his  manner,  which  at  first  gave  promise 
of  answering  well ;  but  it  soon  appeared 
that  they  were  not  durable,  the  fluid 
undergoing  some  chemical  change  which 
entirely  destroyed  its  virtue.  Professor 
Barlow,  of  Woolwich,  has  al^o  made  nu- 
merous experiments  on  this  subject.  His 
correcting  lens  is  formed  of  the  liquid 
sulphuret  of  carbon,  inclosed  between 
two  disks  of  glass,  and  a  ring  of  the  same 
materia],  the  fluid  being  introduced  at  a 
high  temperature.  A  telescope  which  he 
made  on  this  principle  had  a  single  ob- 
ject-lens of  7-8  inches,  and  the  fluid  lens 


404 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[oil 


was  placed  at  the  distance  of  40  inches 
behind  it.  The  performance  of  this  tele- 
scope was,  however,  far  inferior  to  an  or- 
dinary one  of  the  same  dimensions,  with 
the  common  double  achromatic  object- 
glass.    See  Lens. 

OBSIDIAN.  A  glassy  lava,  first  men- 
tioned by  Pliny,  as  found  in  Ethiopia.  It 
is  of  various  colors,  usually  black,  and 
nearly  opaque ;  it  is  also  called  volcanic 
glass,  and  resembles  the  coarse  slags  of 
glass  meltings.  It  is  occasionally  made 
into  rings  and  cutting  tools  in  Mexico  and 
Peru,  it  is  a  fused  silicate  of  alumina 
with  a  little  potash  and  protoxide  of 
iron. 

OCHRE,  an  earth  colored  by  some  me- 
tallic oxide.  Ochres  are  generally  yellow, 
red,  and  brown ;  the  tints  are  mostly  pro- 
duced by  oxide  of  iron,  and  the  darker 
tints  are  rendered  bright  by  calcination. 
The  earth  from  which  ochre  is  formed 
contained  originally  either  sulphuret  of 
iron  (pyrites),  or  silicate  of  iron,  as  in 
Basaltic  rocks,  which,  decomposing,  fur- 
nishes oxide  of  iron  to  color  the  clay. 
They  are  ground  and  used  for  out-door 
painting,  and  as  a  polishing  substance. 

ODOMETER  (See  Perambulator). 

OIL.  The  term  oil  is  applied  to  two 
dissimilar  and  distinct  organic  products, 
which  are  usually  called  fixed  oils,  and 
volatile  oils.  The  fixed  or  fat  oils  are 
either  of  vegetable  or  animal  origin ;  they 
are  compounds  of  carbon,  hydrogen,  and 
oxygen;  the  relative  proportions  vary 
butlittle  in  the  several  species.  The  fol- 
lowing analyses  of  olive  and  spermaceti 
oil  may  be  assumed  as  types  of  the  rest : 

Olive  Oil.  Spermaceti  Oil. 

Carbon 772  780 

Hydrogen 133  118 

Oxygen 95  102 

1000  1000 

The  fixed  oils  abound  in  the  fruit  and 
seed  of  certain  plants  ;  they  are  lighter 
than  water,  unctuous,  and  insipid,  or 
nearly  so :  some  of  these  require  a  low 
temperature  for  their  congelation,  such  as 
linseed  oil ;  others,  such  as  olive  oil,  con- 
crete at  a  temperature  higher  than  the 
freezing  point  of  water;  some  are  solid  at 
common  temperature^  such  as  cocoa-nut 
oil.  Some  or  these  oils  when  exposed  to 
air  absorb  oxygen,  and  gradually  harden, 
forming  a  kind  of  varnish ;  these  are 
called  drying  oils,  and  are  the  basis  of 
paints,  such  as  linseed  oil ;  others  be- 
come rancid,  as  almond  oil.  All  these 
oils,  like  the  different  kinds  of  fat,  con- 
sist of  two  proximate  principles,  called 


stearme  and  elaine — the  former  is  the 
fatty  portion,  which  first  concretes  on 
cooling  the  oil,  and  from  which  the 
elaine,  or  oily  portion,  may  be  separated 
by  pressure.  These  oils  cannot  be  vola- 
tilized without  decomposition.  At  a  red 
heat  they  are  resolved  into  volatile  and 
gaseous  products,  among  which  carbur- 
etted  hydrogen,  in  several  of  its  forms 
predominates ;  hence  the  use  of  these 
oils,  when  volatilized  and  burned  by  the 
aid  of  a  wick,  as  sources  of  artificial  light. 
The  action  of  the  alkali  on  the  fat  oils  is 
highly  important,  as  forming  soap. 

The  volatile  oils  are  generally  obtained 
by  distilling  the  vegetables,  which  afford 
them,  with  water;  they  fluctuate  in 
density  a  little  on  either  side  of  water ; 
they  are  sparingly  soluble  in  water,  form- 
ing the  perfumed  or  medicated  waters, 
such  as  rose  and  peppermint  water ;  they 
are  mostly  soluble  in  alcohol,  forming 
essences.  A  few  of  them,  such  as  oil  of 
turpentine,  of  lemon  peel,  of  copivi  bal- 
sam, &c,  are  hydrocarbons,  that  is,  con- 
sist of  carbon  and  hydrogen  only ;  the 
greater  number,  however,  contain  oxy- 

fen  as  one  of  their  ultimate  elements, 
'hey  are  chiefly  used  in  medicine  and  in 
perfumery,  and  a  few  of  them  are  exten- 
sively employed  in  the  arts  as  vehicles 
for  colors,  and  in  the  manufacture  of  var- 
nishes ;  thi»  is  especially  the  case  with 
oil  of  turpentine. 

The  fixed  or  fat  oils  are  widely  distri- 
buted through  the  organs  of  vegetable 
and  animal  nature.  They  are  found  in 
the  seeds  of  many  plants,  associated  with 
mucilage,  especially  in  those  of  the  dico- 
tyledinous  class,  occasionally  in  the  fleshy 
pulp  surrounding  some  seeds,  as  the 
olive ;  also  in  the  kernels  ot  many  fruits, 
as  of  the  nut  and  almond  tree,  and  finally 
in  the  roots,  barks,  and  other  parts  of 
plants.  In  animal  bodies,  the  oily  mat- 
ter occurs  inclosed  in  thin  membraneous 
cells,  between  the  skin  and  the  flesh,  be- 
tween the  muscular  fibres,  within  the  ab- 
dominal cavity  in  the  omentum,  upon  the 
intestines,  and  round  the  kidneys,  and 
in  a  bony  receptacle  of  the  scull  of  the 
spermaceti  whale ;  sometimes  in  special 
organs,  as  of  the  beaver;  in  the  gall- 
bladder, Ac.,  or  mixed  in  a  liquid  state 
with  other  animal  matters,  as  in  the 
milk. 

Braconnot,  but  particularly  Kaspail, 
have  shown  that  animal  fats  consist  oi 
small  microscopic,  partly  polygonal,  and 
partly  reniform  particles,  associated  by 
means  of  their  containing  sacs.  These 
may  be  separated  from  each  other  by 


oil] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


405 


tearing  the  recent  fat  asunder,  rinsing  it 
with  water,  and  passing  it  through  a 
sieve.  The  membranes  being  thus  re- 
tained, the  granular  particles  are  observed 
to  float  in  the  water,  and  afterwards  to 
separate,  like  the  globules  of  starch,  in  a 
white  pulverulent" semi-crystaline  form. 
The  particles  consist  of  a  strong  mem- 
braneous skin,  inclosing  stearme  and 
elaine,  or  solid  and  liquid  fat,  which  may 
be  extracted  by  trituration  and  pressure. 
These  are  lighter  than  water,  but  sink 
readily  in  spirits  of  wine.  "When  boiled 
in  strong  alcohol,  the  oily  principle  dis- 


solves, but  the  fatty  membrane  remains. 
These  granules  have  different  sizes  and 
shapes  in  different  animals ;  in  the  calf, 
the  ox,  the  sheep,  they  are  polygonal,  and 
from  1-70  to  1-450  of  an  inch  in  diame- 
ter; in  the  hog  they  are  kidney-shaped, 
and  from  1-70  to  1-140  of  an  inch ;  in 
man,  they  are  polygonal,  and  from  1-70 
to  1-900  of  an  inch ;  in  insects  they  are 
usually  spherical,  and  nut  more  than 
1-600  of  an  inch. 

Dr.  Ure,  in  his  valuable  dictionary  of 
arts,  &c,  gives  the  following  table  of 
plants  yielding  fat  oils  of  commerce  : — 


No. 

Plants. 

Oil!. 

Spec,  grarit; . 

1 

Linum  usitatissum  et  perenne 

Corylcus  avellana   ? 

09347 

2 

Nut  oil 

09260 

3 
4 

Juglans  regia \    

0-9243 

5 

09976 

fi 

7 

09176 

8 
9 

09180 

10 

Cucurbita  pepo,  and  melapepo 

Fagus  silvatica 

09231 

11 

09225  ' 

1*> 

09160 

13 

Helianthus  annuus  et  perennis 

09262 

11 

09136 

n 

0  9611 

16 

0-9232 

17 

09127 

1R 

0-9202 

19 

0-8920 

90 

91 

Cocus  butyracea  vel  avoira  elais 

Lau rus  nobilis 

0-9680 

99 

93 

94 

0-9260 

W 

0-9981 

9fi 

0-9252 

97 

0-9358 

98 

0-9240 

99 

Oil  of  deadly  nightshade 

0-9250 

30 

31 

0-9136 

39 

09139 

33 

0-9187 

34 

Cherry-stone  oil 

09239 

.35 

36 

Euonymus  Europaeus 

0-9380 

37 

38 

Oil  of  the  roots  of  cyper  grass. . . 

09180 

39 

0-9130 

40 

0-9270 

41 

0-2850 

The  fat  oils  are  contained  in  that  part 
of  the  seed  which  gives  birth  to  the  coty- 
ledons ;  they  are  not  found  in  the  plum- 
ttla  and  radicle.  Of  all  the  families  of 
plants,  the  cruciform  is  the  richest  in  I 
oieiferous  seeds ;  and  next  to  that  are  the 
drupacece,  amentacese,  and  solanese.  The 


seeds  of  the  graminese  and  leguminosa 
contain  rarely  more  than  a  trace  of  fat 
oil.  One  root  alone,  that  of  the  cyperti* 
e8<yulenta,  contains  a  fat  oil.  The  quan- 
tity of  oil  furnished  by  seeds  varies  not 
only  with  the  species,  but  in  the  same 
seed,  with  culture  and  climate.     Nuts 


406 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[oil 


contain  about  half  their  weight  of  oil : 
tl  e  seeds  of  the  brassica  meracea  ana 
campestris,  one  third ;  the  variety  called 
colza  in  France,  two  fifths;  hempseed, 
one  fourth  ;  and  linseed  from  one  fourth 
to  one  fifth.  Unverdorben  states  that  a 
last  or  ten  quarters  of  linseed  yields  40 
ahms=120  gallons  of  oil ;  which  is  about 
1  cwt.  of  oil  per  quarter. 

The  fat  oils,  when  first  expressed  with- 
out much  heat,  taste  merely  unctuous  on 
the  tongue,  and  exhale  the  odor  of  their 
respective  plants.  They  appear  quite 
neutral  by  litmus  paper.  Their  fluidity 
is  very  various,  some  being  solid  at  ordi- 
nary temperatures,  and  others  remaining 
fluid  at  the  freezing  point  of  water.  Lin- 
seed oil  indeed  does  not  congeal  till  cool- 
ed from  4°  to  18°  below  0°  F.  The  same 
kind  of  seed  usually  affords  oils  of  diffe- 
rent degrees  of  fusibility ;  so  that  in  the 
progress  of  refrigeration  one  portion  con- 
cretes before  another.  Chevreul,  who 
was  the  first  to  observe  this  fact,  consid- 
ers all  the  oils  to  be  composed  of  two 
species,  one  of  which  resembles  suet,  and 
was  thence  styled  by  him  stearine  ;  and 
another  which  is  liquid  at  ordinary  tern- 

Seratures,  and  was  called  elaine,  or  oleint. 
>y  refrigeration  and  pressure  between 
the  folds  of  blotting  paper,  or  in  linen 
bags,  the  fluid  part  is  separated,  and  the 
solid  remains.  By  heating  the  paper  in 
water,  the  liquid  oil  may  be  obtained 
separate.  When  alcohol  is  boiled  with 
the  natural  oil,  the  greater  part  of  the 
stearine  remains  undissolved. 

Oleine  may  also  be  procured  by  digest- 
ing the  oil  with  a  quantity  of  caustic 
soda,  equal  to  one  half  of  what  is  requi- 
site to  saponify  the  whole ;  the  stearine  is 
first  transformed  into  soap,  then  a  por- 
tion of  the  oleine  undergoes  the  same 
change,  but  a  great  part  of  it  remains  in 
a  pure  state.    This  process  succeeds  only 
with  recently  expressed  or   very  fresh  i 
oils.     The  properties  of  these  two  prin-  j 
ciples  of  the  fat  oils  vary  with  the  nature  i 
of  the  respective  oils,  so  that  the  soledil-  ! 
ference  does  not  consist,  as  many  sup-  , 
pose,  in  tne  different  proportions  of  these  j 
two  bodies,  but  also  in  peculiarities  of  the 
several  stearines  and  oleines,  which,  as 
extracted  from  different  seeds,  solidify  at 
very  different  temperatures. 

In  close  vessels,  oils  may  be  preserved 
fresh  for  a  very  long  time,  but  with  con- 
tact of  air  they  undergo  progressive 
changes.  Certain  oils  thicken  and  even- 
tually dry  into  a  transparent,  yellowish, 
flexible  substance;  which  forms  a  skin 
upon  the  surface  of  the  oil,  and  retards 


its  further  alteration.  Such  oils  i  re  said 
to  be  drying  or  siccative,  and  are  used  on 
this  account  in  the  preparation  of  var- 
nishes and  painter's  colors.  Other  oils 
do  not  grow  dry,  though  they  turn  thick, 
become  less  combustible,  and  assume  an 
offensive  smell.  They  are  then  called 
rancid.  In  this  state  they  exhibit  an 
acid  reaction,  and  irritate  the  fauces  when 
swallowed,  in  consequence  of  the  pre- 
sence of  a  peculiar  acid,  which  may  be 
removed  in  a  great  measure  by  boiling 
the  oil  along  with  water  and  a  little  com- 
mon magnesia  for  a  quarter  of  an  hour, 
or  till  it  has  lost  the  property  of  redden- 
ing litmus.  While  oils  undergo  the  above 
changes,  they  absorb  a  quantity  of  oxy- 
gen equal  to  several  times  their  volume. 
Saussure  found  that  a  layer  of  nut  oil, 
one  quarter  of  an  inch  thick,  inclosed 
along  with  oxygen  gas  over  the  surface 
of  quicksilver  in  the  shade,  absorbed 
only  three  times  its  bulk  of  that  gas  in 
the  course  of  eight  months;  but  when 
exposed  to  the  sun  in  August,  it  absorb- 
ed 60  volumes  additional  in  the  course  of 
ten  days.  This  absorption  of  oxygen 
diminished  progressively,  and  stopped 
altogether  at  the  end  of  three  months, 
when  it  had  amounted  to  145  times  the 
bulk  of  the  oil.  No  water  was  generated, 
but  21*9  volumes  of  carbonic  acid  were 
disengaged,  while  the  oil  was  transform- 
ed in  an  anomalous  manner  into  a  gelati- 
nous mass,  which  did  not  stain  paper. 
To  a  like  absorption  we  may  ascribe  the 
elevation  of  temperature  which  happens 
when  wool  or  hemp,  besmeared  with 
olive  or  rapeseed  oil,  is  left  in  a  heap ; 
circumstances  under  which  it  has  fre- 
quently taken  fire,  and  caused  the  de- 
struction of  both  cloth-mills  and  dock- 
yards. 

In  illustration  of  these  accidents,  if 
paper,  linen,  tow,  wool,  cotton,  mats, 
straw,  wood  shavings,  moss,  or  soot,  be 
imbued  slightly  with  linseed  or  hemp- 
seed  oil,  and  placed  in  contact  with  the 
sun  and  air,  especially  when  wrapped  or 
piled  in  a  heap,  they  very  soon  become 
spontaneously  hot,  emit  smoke,  and  fin- 
ally burst  into  flames.  If  linseed  oil  and 
ground  manganese  be  triturated  together, 
the  soft  lump  so  formed  will  speedily  be- 
come firm,  and  ere  long  take  fire. 

The  fat  oils  are  completely  insoluble  in 
water.  When  agitated  with  it,  the  mix- 
ture becomes  turbid,  but  if  it  be  allowed 
to  settle,  the  oil  collects  by  itself  upon 
the  surface.  This  method  of  washing  is 
often  employed  to  purify  oils.  Oils  are 
little  soluble  in  alcohol,  except  at  high 


oil] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


407 


temperatures.  Caster  oil  is  the  only  one 
which  dissolves  in  cold  alcohol.  lather, 
however,  is  an  excellent  solvent  of  oils, 
and  is  therefore  employed  to  extract  them 
from  other  bodies  in  analysis ;  after 
which  it  is  withdrawn  by  distillation. 

Fat  oils  may  be  exposed  to  a  consider- 
ably high  temperature,  without  under- 
going much  alteration;  but  when  they 
are  raised  to  nearly  their  boiling  point, 
they  begin  to  be  decomposed.  The 
vapors  that  then  rise  are  not  the  oil 
itself,  but  certain  products  generated  in 
it  by  the  heat.  These  changes  begin 
somewhere  under  600°  of  Fahr.,  and  re- 
quire for  their  continuance  temperatures 
always  increasing.  The  products  con- 
sist at  first  in  aqueous  vapor,  then  a  very 
inflammable  volatile  oil,  which  causes 
boiling  oil  to  take  fire  spontaneously ; 
and  next  carbureted  hydrogen  gas,  with 
carbonic  acid  gas.  In  a  lamp,  a  small 
portion  of  oil  is  raised  in  the  wick  by 
capillarity,  which  being  heated,  boils  and 
burns.     {See  Kosin-Gas.) 

Several  fat  oils,  mixed  with  one  or  two 
per  cent,  of  sulphuric  acid,  assume  in- 
stantly a  dark  green  or  brown  hue,  and, 
when  allowed  to  stand  quietly,  deposit 
a  coloring  matter  after  some  time.    It 

Carbon. 

Castor  oil 7400 

Stearine  of  olive  oil 82.17 

Oleine  of  do 76  03 

Linseed  oil 76-01 

Nut  oil 79-77 

Oil  of  almonds 77*40 

De  Saussure  concludes  that  the  less 
fusible  fats  contain  more  carbon  and  less 
oxygen,  and  that  oils  are  more  soluble  in 
alchohol,  the  more  oxygen  they  contain. 

Oil  of  almonds,  according  to  Gusseron, 
contains  no  stearine ;   at  least  he  could 
obtain  none  by  cooling  it  and  squeezing  j 
it  successively  till  it  all  congealed. 

Oil  of  colza  is  obtained  from  the  seeds  j 
of  brassica  campestris,  to  the  amount  of 
39  per  cent,  of  their  Aveight.    It  forms  an 
excellent  lamp  oil,  and  is  much  employed 
in  France. 

The  corylus  avellana  furnishes  in  oil  60 
per  cent,  of  the  weight  of  the  nuts. 

Hempseed  oil  resembles  the  preceding, 
but  has  a  disagreeable  smell,  and  a 
mawkish  taste.  It  is  used  extensively 
for  making  both  soft  soap  and  varnishes. 

Linseed  oil  is  obtained  in  greatest  puri- 
ty by  cold  pressure ;  but,  by  a  steam  heat 
of  about  200°  F.,  a  very  good  oil  may  be 
procured  in  larger  quantity.  The  pro- 
portion of  oil  usually  stated  by  authors  is 
22  per  cent,  of  the  weight  of  the  seed ; 


consists  in  a  chemical  combination  of  the 
sulphuric  acid,  with  a  body  thus  separat- 
ed from  the  oil,  which  becomes  in  con- 
sequence more  limpid,  and  burns  with  a 
brighter  flame,  especially  after  it  is  wash- 
ed with  steam,  and  clarified  by  repose  or 
filtration.  Any  remaining  moisture  may 
be  expelled  by  the  heat  of  a  water  bath. 

The  oils  combine  with  the  salifiable 
bases,  and  give  birth  to  the  substance 
called  glycerine,  (the  sweet  principle,)  and 
to  the  margaric,  oleic,  and  stearic  acids. 
The  general  product  of  their  combination 
with  potash  or  soda,  is  Soap,  which  see. 
Caustic  ammonia  changes  the  oils  very 
difficultly  and  slowly  into  a  soap  ;  but  it 
readily  unites  with  them  into  a  milky 
emulsion  called  volatile  liniment,  used  as 
a  rubefacient  in  medicine.  Upon  mix- 
ing water  with  this  liquor,  the  oil  separ- 
ates in  an  unchanged  state.  By  longer 
contact,  ammonia  acts  upon  oils  like  the 
other  alkalies.  Sea-salt  dissolves  in  small 
quantity  in  the  oils,  and  so  does  verdigris. 
The  latter  solution  is  green.  Oils  dis/- 
solve  also  several  of  the  vegetable  alkalies, 
as  morphia,  cinchonia,  quinia,  strychia, 
and  delphia. 

The  following  is  the  chemical  composi- 
tion of  a  few  of  the  fixed  oils : — 


II, 

drogen. 

Oxygen. 

Azote. 

10-30 

15-70 

11-23 

6-30 

0-30  Saussure. 

11-54 

1207 

0-35          do. 

11-35 

12-64 

do. 

10-57 

9-12 

0-54         do. 

11-48 

10-83 

0-29 

but  by  hydraulic  pressure,  from  26  to  27 
is  obtained.  It  dissolves  in  5  parts  of 
boiling  alcohol,  in  40  parts  of  cold  alco- 
hol, and  in  1-6  parts  of  ether.  When 
kept  long  cool  in  a  cask  partly  open,  it 
deposits  masses  of  white  stearine 
along  with  a  brownish  powder.  That 
stearine  is  very  difficult  of  saponifica- 
tion. 

Mustard-seed  oil.  The  white  or  yellow 
seed  affords  36  per  cent,  of  oil,  and  the 
black  seed  18  per  cent.  The  oil  con- 
cretes when  cooled  a  little  below  32°  F. 

Nut  oil  is  at  first  greenish  colored,  but 
becomes  pale  yellow  by  time.  It  con- 
geals at  the  same  low  temperature  as  lin- 
seed oil,  into  a  white  mass,  and  has  a 
more  drying  quality  than  it. 

Oil  of  olives  is  sometimes  of  a  greenish, 
and  at  others  of  a  pale  yellow  color.  It 
is  prepared  from  ripe  olives,  gathered 
late  in  autumn.  The  pulp  is  separated 
from  the  kernels  by  passing  them  be- 
tween stones  :  they  are  then  pressed  in 
rush  bags  :  its  specific  gravity  is  915.     A 


408 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


OIL 


few  degrees  above  32°  F.  it  begins  to  de- 
posit some  white  granules  of  stearine, 
especially  if  the  oil  have  been  originally 
expressed  with  heat.  At  22°  it  deposits 
28  per  cent,  of  its  weight  in  stearine, 
which  is  fusible  again  at  68°,  and  affords 
72  per  cent,  of  oleine.  According  to 
Kerwych,  oleine  of  singular  beauty  may 
be  obtained  by  mixing  2  parts  of  olive  oil 
with  1  part  of  caustic  soda  ley,  and  ma- 
cerating the  mixture  for  24  hours  with 
frequent  agitation.  Weak  alcohol  must 
then  be  poured  into  it,  to  dissolve  the 
stearine  soap,  whereby  the  oleine,  which 
remains  meanwhile  unsaponified,  is  se- 

{jarated,  and  floats  on  the  surface  of  the 
iquid.  This  being  drawn  off,  a  fresh 
Quantity  of  spirits  is  to  be  poured  in,  till 
tne  separation  of  all  the  oleine  be  com- 
pleted. It  has  a  slightly  yellowish  tint, 
which  may  be  removed  by  means  of  a 
little  animal  charcoal  mixed  with  it  in  a 
warm  place  for  24  hours.  By  subsequent 
filtration,  the  oleine  is  obtained  limpid 
and  colorless,  of  such  quality  that  it  does 
not  thicken  with  the  greatest  cold,  nor 
does  it  affect  either  iron  or  copper  instru- 
ments immersed  in  it. 

There  are  three  kinds  of  olive  oil  in 
the  market.  The  best,  called  virgin 
salad  oil,  is  obtained  by  a  gentle  pres- 
sure in  the  cold:  the  more  common 
sort  is  procured  by  stronger  pressure, 
aided  with  the  heat  of  boiling  water; 
and  thirdly,  an  inferior  kind,  by  boiling 
the  olive  residuum,  or  marc,  with  water, 
whereby  a  good  deal  of  mucilaginous  oil 
rises  and  floats  on  the  surface.  The  lat- 
ter serves  chiefly  for  making  soaps.  A 
still  worse  oil  if*  got  by  allowing  the  mass 
of  bruised  olives  to  ferment  before  sub- 
jecting it  to  pressure. 

Oil  of  olives  is  refined  for  the  watch- 
makers by  the  following  simple  process  : 
Into  a  bottle  or  vial  containing  it,  a  slip 
of  sheet  lead  is  immersed,  and  the  bottle 
is  placed  at  a  window,  where  it  may  re- 
ceive the  rays  of  the  sun.  The  oil  by 
degrees  gets  covered  with  a  curdy  mass*, 
which  after  some  time  settles  to  the  bot- 
tom, while  itself  becomes  limpid  and 
colorless.  As  soon  as  the  lead  ceases  to 
separate  any  more  of  that  white  sub- 
stance, the  oil  is  decanted  off  into  another 
vial  for  use. 

Palm,  oil  melts  at  117-5°  F.,  and  is  said 
to  consist  of  31  parts  of  stearine  and  69 
of  oleine  in  100.  It  becomes  readily  ran- 
cid by  exposure  to  air,  and  is  whitened 
at  the  same  time. 

The  oil  extracted  from  the  plucked 
tops  of  the  pvrws  abies,  in  the  Black  For- 


est in  Germany,  is  limpid,  of  a  golden 
yellow  color,  and  resembles  in  smell  and 
taste  the  oil  of  turpentine.  It  answers 
well  for  the  preparation  of  varnishes. 

Poppy-seed  oil  has  none  of  the  narcotic 
properties  of  the  poppy  juice.  It  is  solu- 
ble in  ether  in  every  proportion. 

Rape-seed  oil  has  a  yellow  color,  and  a 
peculiar  smell.  At  25°  F.  it  becomes  a 
yellow  mass,  consisting  of  46  parts  of 
stearine,  which  fuses  at  50°,  and  54  of 
oleine,  in  which  the  smell  resides. 

The  sun-flower  is  largely  cultivated  in 
this  country,  for  the  sake  of  the  oil.  An 
acre  yields  from  60  to  75  bushels,  and 
every  bushel  gives  a  gallon  of  oil.  The 
oil-cake  is  a  fine  fattener  for  cattle. 

Oil  of  almonds  is  manufactured  by  agi- 
tating the  kernels  in  bags,  so  as  to  sepa- 
rate their  brown  skins,  grinding  them  in 
a  mill,  then  enclosing  them  in  bags,  and 
squeezing  them  strongly  between  a  series 
ot  cast  iron  plates,  in'a  hydraulic  press ; 
without  heat  at  first,  and"  then  between 
heated  plates.  The  first  oil  is  the  purest, 
and  least  apt  to  become  rancid.  It  should 
be  refined  by  filtering  through  porous 
paper.  Next  to  6live  oil,  this  species  is 
the  most  easy  to  saponify.  Bitter  al- 
monds, being  cheaper  than  the  sweet, 
are  used  in  preference  for  obtaining  this 
oil,  and  they  afford  an  article  equally 
bland,  wholesome,  and  inodorous.  But 
a  strongly  scented  oil  may  be  procured, 
according  to  M.  Planche,  by  macerating 
the  almonds  in  hot  water,  so  as  to  blanch 
them,  then  drying  them  in  a  stove,  and 
afterwards  subjecting  them  to  pressure. 
The  volatile  oil  of  almonds  is  obtained 
by  distilling  the  marc  or  bitter  almond 
cake,  along  with  water. 

Linseed,  rapeseed,  poppyseed,  and 
other  oleiferous  seeds  were  formerly 
treated  for  the  extraction  of  their  oil,  by 
pounding  in  hard  wooden  mortars  with 
pestles  shod  with  iron,  set  in  motion  by 
cams  driven  by  a  shaft  turned  with  horse 
or  water  power,  then  the  triturated  seed 
was  put  into  woollen  bags  which  were 
wrapped  up  in  hair-cloths,  and  squeezed 
between  upright  wedges  in  press-boxes 
by  the  impulsion  of  vertical  rams  driven 
also  by  a  cam  mechanism.  In  the  best 
mills  upon  the  old  construction,  the 
cakes  obtained  by  this  first  wedge  pres- 
sure were  thrown  upon  the  bed  of  an 
edge-mill,  ground  anew  and  subjected  to 
a  second  pressure,  aided  by  heat  now,  as 
in  the  first  case.  These  mortars  and 
press-boxes  constitute  what  are  called 
Dutch  mills. 

A  good  oil  for  chronometers  is  a  great 


oil] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


409 


desideratum.  The  following  has  been 
tried,  and  is  much  used : — Having  pro- 
cured good  olive  oil,  put  about  one  gallon 
into  a  cast-iron  vessel  capable  of  holding 
two  gallons :  place  it  over  a  slow,  clear 
fire,  Keeping  a  thermometer  suspended 
.n  it ;  and,  when  the  temperature  rises 
to  920°,  check  the  heat,  never  allowing  it 
to  exceed  230°,  nor  descend  below  212°, 
for  one  hour ;  by  which  time  the  whole 
of  the  water  and  acetic  acid  will  be  eva- 
porated. The  oil  is  then  exposed  to  a 
temperature  of  30°  to  36°,  for  two 
or  three  days.  By  this  operation,  a 
considerable  portion  is  congealed;  and, 
while  in  this  state,  pour  the  whole  on  a 
muslin  filter,  to  allow  the  fluid  portion 
to  run  through ;  the  solid,. when  re-dis- 
solved, may  be  used  for  common  pur- 
poses. Lastly,  the  fluid  portion  must  be 
filtered,  once  or  more,  through  newly- 
prepared  animal  charcoal,  grossly  pow- 
dered, or  rather  broken,  and  placed  on 
bibulous  paper  in  a  wire-frame,  within  a 
funnel :  by  which  operation  rancidity  (if 
any  be  present)  is  entirely  removed,  and 
the  oil  is  rendered  perfectly  bright  and 
colorless. 

Oil,  for  delicate  machinery,  should  be 
purified  from  its  stearine,  or  fatty  mat- 
ter, which  is  effected  by  gradually  boil- 
ing it  with  eight  times  its  weight  of  alco- 
hol. When  cold,  the  stearine  separates 
in  a  precipitate,  and  the  liquid  is  to  be 
evaporated  to  a  fifth,  which  is  pure  elaine, 
or  oil,  without  any  chemical  action  or 
odour. 

Oils  in  painting  afterward  fatten  and 
do  not  dry,  owing  either  to  want  of  com- 
bination in  the  pigment,  or  to  the  oil  not 
being  old  enough.  Olive  oil,  for  exam- 
ple, will  not  dry — even  several  samples 
vary  in  this  defect.  Keeping,  and  the 
use  of  some  drying  substance,  are  the 
best  remedies.  Oils  are  adopted  because 
they  give  an  equal  surface  and  a  subse- 
quent body. 

Drying  oils,  by  boiling,  or  sometimes 
by  setting  on  fire,  by  which  they  cease 
to  stain  paper,  are  linseed,  walnut,  hemp, 
poppy,  castor,  croton,  grapeseed,  night- 
shade, tobacco,  henbane,  sun-flower,  and 
cress. 

Drying  oils  are  best  prepared  by  boil- 
incr  a  gallon  of  linseed  oil  with  It  lb.  of 
red  lead,  and  leaving  it  to  stand  till  the 
lead  has  subsided.  Other  materials  effect 
the  same  purpose,  as  white  vitriol,  sugar 
of  lead,  gum  mastic,  &c,  where  long 
boiling  is  inconvenient.  Or,  take  half  a 
gallon  of  linseed  oil,  and  slowly  boil  it 
with  6  oz.  of  litharge,  and  li  of  white 


vitriol,  till  no  more  scum  arises.  Let  it 
cool  and  settle,  and  then  pour  ott  the 
clear  into  small  vessels,  and  in  ten  days 
it  will  be  fit  for  use.  Or,  suspending  in 
boiling  oil  a  bag  of  litharge  and  white 
vitriol  for  4  or  5  hours.  Or,  well  stir  a 
lb.  of  white  lead  with  a  gallon  of  linseed 
oil,  and  leave  it  to  settle  for  8  or  10  days. 

Fat  oils  generally  may  acquire  a  drying 
quality  by  the  following  treatment: — 
Take  of  nut  oil,  or  linseed  oil,  8  lbs. ; 
white  lead,  slightly  calcined;  sugar  of 
lead,  also  calcined ;  white  vitriol :  of  each 
1  oz.  Litharge,  12  oz.,  a  head  of  garlic, 
or  a  small  onion.  When  these  are  pul- 
verized, mix  them  with  the  garlic  and  oil 
over  a  fire  capable  of  maintaining  the  oil 
in  a  slight  state  of  ebullition  :  continue 
it  till  the  oil  ceases  to  throw  up  scum, 
assumes  a  reddish  color,  and  the  garlic, 
or  onion,  becomes  brown.  A  pellicle  in- 
dicates that  the  operation  is  completed. 
Take  the  vessel  from  the  fire,  and  the 
pellicle,  precipitated  by  rest,  will  carry 
with  it  the  unctuous  parts.  When  the 
oil  becomes  clear,  separate  it  from  the 
deposit,  and  put  it  into  wide-mouthed 
bottles,  where  it  will  completely  clarify 
itself. 

In  all  cases,  where  preparations  of  lead 
are  employod  for  freeing  oils  from  greasy 
principles,  the  mixture  should  not  be 
stirred.  It  is  sufficient  to  leave  the  mix- 
ture over  a  gentle  fire,  capable  of  pro- 
ducing slight  ebullition.  The  garlic 
merely  indicates  the  moment  when  the 
aqueous  part  is  evaporated. 

Drying  oil  is  employed  by  those  who 
paint  pictures,  and  it  enters  into  the 
composition  of  varnishes.  It  serves  it- 
self also  as  varnish,  either  employed 
alone,  or  diluted  with  oil  of  turpentine. 

For  house  painting,  it  is  advantageous 
to  use,  for  the  last  coating,  resinous  dry- 
ing oil,  as  a  varnish.  It  is  prepared  as 
follows : — Take  10  lbs.  of  drying  nut  oil, 
if  the  paint  be  designed  for  external  sur- 
faces, or  10  lbs.  of  drying  linseed  oil,  if 
for  internal.  Yellow  resin  3  lbs.,  com- 
mon turpentine  6  oz.  Melt  the  resin,  to 
which  add  the  turpentine,  and  lastly,  the 
oil,  so  as  not  to  coagulate  the  resin ; 
leave  the  varnish  at  rest,  by  which 
means  it  will  often  deposit  portions  of 
resin  and  other  impurities ;  preserve  it 
in  wide-mouthed  bottles.  It  must  be 
used  fresh  :  when  suffered  to  grow  old, 
it  deposits  some  of  its  resin.  If  this  re- 
sinous oil  become  too  thick,  dilute  it 
with  a  little  oil  of  turpentine,  or  with  oil 
of  poppy,  if  intended  for  articles  shelter- 
ed from  the  sun. 

18 


410 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[on, 


OIL  GAS.  The  inflammable  gases 
and  vapors  (chiefly  hydrocarbons)  which 
are  obtained  by  passing  fixed  oils  through 
red-hot  tubes,  and  which  may  be  used  as 
ooalaas,  for  the  purposes  of  illumination; 
it  yields  a  more  brilliant  light  than  the 
latter ;  but  is,  in  most  instances,  too  ex- 
pensive to  be  generally  adopted.  Brande 
states  that  a  gallon  of  common  whale  oil 
yields  from  90  to  100  cubical  feet  of  gas  ; 
and  an  Argand  burner,  giving  the  light 
of  six  or  seven  wax  candles,  consumes 


from  li  to  2  cubical  feet  per  hour; 
whereas,  to  produce  the  same  light,  from 
5  to  6  cubic  feet  of  coal  gas  are  required. 
Another  estimate  is  given  below. 

Purified  oil  is  never  used,  as  gas  can 
be  obtained  from  impure  oils,  train  oil, 
or  refuse  feet,  with  as  much  ease  as  from 
the  purer  kinds.  It  is  a  good  means  for 
using  up  such  materials.  The  results 
obtained  by  Henry,  show  the  following 
results  in  100  parts  of  illuminating  gas : — 


Substance  distilled. 


Oil 

Train  oil 


Temperature  of  distillation 


Bright  red  heat . 

Do. 
Lowest  possible  heat.. 
Low  red  heat . . . 


o 

-  -• 

« 

10 

•d  2 

•§1 

tr% 

1  ** 

I2 

i 

H 

o 

1 
6 

! 

X 

0464 

6 

28-2 

141 

451 

0-590 

19 

32-4 

12-2 

32-4 

0758 

22-5 

50-3 

15-5 

77 

0-906 

38- 

46-5 

9-5 

3- 

6-6 
4 
4 
3 


From  the  above,  it  appears  that  oil  gas 
is  superior  to  that  obtained  from  coal,  as 
shown  by  its  gravity,  and  that  the  pro- 
duce is  of  the  best  quality  when  obtained 
at  a  low  red  heat.  This  temperature  is 
sufficient  to  convert  the  oil  into  gas,  but 
is  not  sufficiently  high  to  decarbonize  the 
gas  to  any  great  extent.  The  apparatus 
for  obtaining  gas  is  simple:  a  retort  is 
filled  with  bricks,  or  lumps  of  coke,  so  as 
to  extend  the  surface  when  heated.  The 
oils  flow  in  a  thin  and  constant  stream 
upon  the  red  hot  bricks,  when  it  is 
almost  immediately  purified  ;  the  gas  is 
carried  on  to  the  hydraulic  main,  and 
from  thence  through  the  purifiers  to  the 
gasometer.  Cast  iron  retorts  are  used ; 
and  1  cubic  foot,  or  4  gallons  of  oil,  pro- 
duce from  600  to  700  cubic  feet  of  gas, 
which  is  equivalent  to  from  90  to  96  per 
cent,  by  weight.  The  remainder  is  de- 
posited carbon.  Oil  gas  contains  much 
more  olefiant  gas  and  naptha  vapors  than 
coal  gas,  and  is  hence  more  valuable  as 
an  illuminating  asrent. 

OIL  OF  BRICKS.  A  term  applied  by 
the  old  chemists  to  the  empyreumatic  oil 
obtained  by  subjecting  a  brick  which  has 
been  soaked  in  oil  to  the  process  of  dis- 
tillation at  a  high  temperature.  The  oil 
is  used  by  lapidaries  as  a  vehicle  for  the 
emery  by  which  stones  and  gems  are 
sawn"  or  cut. 

OILS,  VOLATILE  OR  ESSENTIAL ; 
Manufacture  of.  The  volatile  oils  occur 
in  every  part  of  oderiferous  plants,  whose 
aroma  they  diffuse  by  their  exhalation ; 
but  in  different  organs  of  different  spe- 


cies. Certain  plants,  such  as  thyme  and 
the  scented  labiata,  in  general  contain 
volatile  oil  in  all  their  parts ;  but  others 
contain  it  only  in  the  blossoms,  the  seeds, 
the  leaves,  the  root,  or  the  bark.  It 
sometimes  happens  that  different  parts 
of  the  same  plant  contain  different  oils ; 
the  orange,  for  example,  furnishes  three 
different  oils,  one  of  which  resides  in  the 
flowers,  another  in  the  leaves,  and  a 
third  in  the  skin  or  epidermis  of  the 
fruit.  The  qantity  of  oil  varies  not  only 
with  the  species,  but  also  in  the  same 
plant,  with  the  soil,  and  especially  the 
climate;  thus  in  hot  countries  it  is  gene- 
rated most  profusely.  In  several  plants, 
the  volatile  oil  is  contained  in  peculiar 
orders  of  vessels,  which  confine  it  so 
closely  that  it  does  not  escape  in  the  dry- 
ing, nor  is  dissipated  by  keeping  the 
plants  for  many  years.  In  other  species, 
and  particularly  in  flowers,  it  is  formed 
continually  upon  their  surface,  and  flics 
off  at  the  moment  of  its  formation. 

Volatile  oils  are  usually  obtained  by 
distillation.  For  this  purpose  the  plant 
is  introduced  into  a  still,  water  is  poured 
upon  it,  and  heat  being  applied,  the  oil  is 
volatilized  by  the  aid  of  the  watery  vapor, 
at  the  temperature  of  212°,  though  when 
alone  it  would  probably  not  distil  over  un- 
less the  heat  were  100*5  more.  When  the 
mingled  vapors  of  the  oil  and  water  are 
condensed  into  the  liquid  state,  by  the 
refrigerator  of  the  still,  the  oil  separates, 
and  either  floats  on  the  surface  or  sinks 
to  the  bottom  of  the  water.  Some  oils  of 
a  less  volatile  nature  require  a  higher 


oil] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


411 


heat  than  212°  to  raise  them  in  vapor, 
and  must  be  dislodged  by  adding  com- 
mon salt  to  the  water,  whereby  the  heat 
being  augmented  by  15°,  they  readily 
come  over. 

There  are  a  few  essential  oils  which 
may  be  obtained  by  expression,  from  the 
substances  which  contain  them ;  such  as 
the  oils  of  lemons  and  bergainot,  found 
in  the  pellicle  of  the  ripe  fruits  of  the 
citrus  aurantium  and  medica  /  or  the 
orange  and  the  citron.  The  oil  comes 
out  in  this  case  with  the  juice  of  the  peel, 
and  collects  upon  its  surface. 

For  collecting  the  oils  of  odoriferous 
flowers  which  have  no  peculiar  organs 
for  imprisoning  them,  and  therefore 
speedily  let  them  exhale,  such  as  violets, 
jasmine,  tuberose,  and  hyacinth,  another 
process  must  be  resorted  to.  Alternate 
layers  are  formed  of  the  fresh  flowers, 
and  thin  cotton  fleece,  or  woollen  cloth- 
wadding,  previously  soaked  in  a  pure 
and  inodorous  fat  oil.  Whenever  the 
flowers  have  given  out  all  their  volatile 
oil  to  the  fixed  oil  upon  the  fibrous  mat- 
ter, they  are  replaced  by  fresh  flowers  in 
succession,  till  the  fat  oil  has  become  sa- 
turated with  the  odorous  particles.  The 
cotton  or  wool  wadding  being  next  sub- 
mitted to  distillation  along  with  water, 
gives  up  the  volatile  oil.  Perfumers 
alone  use  these  oils  ;  they  employ  them 
either  mixed  as  above,  or  dissolve  them 
out  by  means  of  alcohol.  In  order  to 
extract  the  oils  of  certain  flowers,  as  for 
instance  of  white  lilies,  infusion  in  a  fat 
oil  is  sufficient. 

Essential  oils  differ  much  from  each 
other  in  their  physical  properties.  Most 
of  them  are  yellow,  others  are  colorless, 
red,  or  brown ;  some  again  are  green, 
and  a  few  are  blue.  They  have  a  power- 
ful smell,  more  or  less  agreeable,  which 
immediately  after  their  distillation  is  oc- 
casionally a  little  rank,  but  becomes  less 
so  by  keeping.     The  odor  is  seldom  as 

?leasant  as  that  of  the  recent  plant. 
'heir  taste  is  acrid,  irritating,  and  heat- 
ing, or  merely  aromatic  when  they  are 
largely  diluted  with  water  or  other  sub- 
stances. They  are  not  greasy  to  the 
touch,  like  the  fat  oils,  but  on  the  con- 
trary make  the  skin  feel  rough.  They 
are  almost  all  lighter  than  water,  only  a 
very  few  falling  to  the  bottom  of  this 
liquid;  their  specific gravitv lies  between 
0-847  and  1.096  ;  the  first  number  denot- 
ing the  density  of  oil  of  citron,  and  the 
second  that  of  oil  of  sassafras.  Although, 
when  exposed  to  the  air,  the  volatile  oils 
change  their  color,  become  darker,  and 


gradually  absorb  orygen.  This  absorp- 
tion commences  whenever  they  are  ex- 
tracted from  the  plant  containing  them  ; 
it  is  at  first  considerable,  and  diminishes 
in  rapidity  as  it  goes  on.  Light  contri- 
butes powerfully  to  this  action,  during 
which  the  oil  disengages  a  little  carbonic 
acid,  but  much  less  than  the  oxygen  ab- 
sorbed ;  no  water  is  formed.  The  oil 
turns  gradually  thicker,  loses  its  smell, 
and  is  transformed  into  a  resin,  which 
becomes  eventually  hard.  De  Saussure 
found  that  oil  of  lavender  recently  dis- 
tilled had  absorbed  in  four  months,  and 
at  a  temperature  below  54°  F.,  52  times 
its  volume  of  oxygen,  and  had  disen- 
gaged twice  its  volume  of  carbonic  acid 
gases  ;  nor  was  it  yet  completely  saturat- 
ed with  oxygen.  The  stearessence  of 
anise-seed  oil  absorbed  at  its  liquefying 
temperature,  in  the  space  of  two  years, 
156  times  its  volume  of  oxygen  gas,  and 
disengages  26  times  its  volume  of  car- 
bonic acid  gas.  An  oil  which  has  begun 
to  experience  such  an  oxydizement  is 
composed  of  a  resin  dissolved  in  the  un- 
altered oil ;  and  the  oil  may  be  separated 
by  distilling  the  solution  along  with 
water.  To  preserve  oils  in  an  unchanged 
state,  they  must  be  put  in  vials,  filled  to 
the  top,  closed  with  ground  glass  stopples, 
and  placed  in  the  dark. 

Volatile  oils  are  little  soluble  in  water, 
yet  enough  so  as  to  impart  to  it  by  agita- 
tion their  characteristic  smell  and  taste. 
The  water  which  distils  with  any  oil  is  in 
general  a  saturated  solution  of  it,  and  as 
such  is  used  in  medicine  under  the  name 
of  distilled  water. 

The  principal  volatile  or  essential  oils 
are  those  of  turpentine,  aniseed,  nutmeg, 
lavender,  cloves,  caraway,  peppermint, 
spearmint,  sassafras,  camomile,  and  ci- 
tron. The  taste  is  acrid  and  burning ; 
and  the  odor  very  pungent,  resembling 
the  taste  and  smell  of  the  vegetables. 
They  boil  at  a  temperature  considerably 
above  that  of  boiling  water;  thus,  oil  of 
turpentine  boils  at  315°.  They  are  solu- 
ble in  strong  alcohol,  but,  on  adding 
water,  are  precipitated.  They  are  solu- 
ble in  ether  in  like  manner,  but  do  not 
form  soaps  with  alkalies,  by  which  they 
are  distinguished  from  the  fixed  oils. 
They  are  readily  inflamed  by  strong  ni- 
tric acid  ;  especially  if  a  little  sulphuric 
acid  be  added,  to  render  the  acid  more 
concentrated.  Exposed  to  the  action  of 
the  air,  they  undergo  an  alteration  in 
consequence  of  the  absorption  of  oxygen, 
become  thickened,  and  gradually  change 
into  a  solid  matter,  resembling  resins. 


412 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[oil 


When  digested  with  sulphur,  they  unite 
with  it,  forming  balsam  of  sulphur. 

One  of  the  most  useful  is  that  of  tur- 
pentine, called  spirit  of  turpentine.  It  is 
obtained  by  distilling  turpentine  and 
water,  in  due  proportions,  in  a  copper 
alembic.  It  is  the  solvent  employed  in 
making  a  variety  of  varnishes,  but  it  re- 
quires to  be  rectified  by  a  second  distilla- 
tion. 

In  general,  volatile  oils  are  used  in 
pharmacy  or  as  perfumes.  Those  ap- 
plied to  the  latter  use,  are  the  essence  of 
roses,  of  jasmine,  violets,  &c,  but  re- 
quire much  care  in  preparation.  This  is 
best  done  by  spreading  upon  white  wool, 
impregnated  with  olive  oil,  the  petals  of 
the  flowers,  and  leaving  them  for  some 
time,  covered  over  with  a  woollen  cloth, 
upon  which  flowers  are  also  scattered. 
The  flowers  are  renewed  from  time  to 
time,  until  the  olive-oil  employed  appears 
to  be  saturated  with  the  oil  of  the  flowers, 
and  this  last  is  then  separated  by  digest- 
ing the  wool  in  alcohol. 

Essential  oils,  as  previously  mentioned, 
are  obtained  by  distilling  the  basis  with 
an  equal  weight  of  water  to  prevent  them 
from  adhering  to  the  still,  and  the  oil  and 
water  acquiring  a  burnt  taste  ;  some,  as 
those  of  the  peels  of  fresh  fruits,  are  ob- 
tained by  rasping  them,  and  pressing  the 
raspings  ;  a  few  by  distilling  the  articles 
with  twice  their  weight  of  water,  adding 

1  lb.  of  salt  to  each  gallon  of  water,  using 
a  quick  fire,  and  when  half  the  water  has 
come  over,  pouring  it  back  again  into  the 
still,  and  thus  cohobating  it.  When  rec- 
tified, for  the  purpose  of  rendering  them 
finer,  they  are  distilled  without  water  in  a 
retort,  and  one  half  the  oil  is  drawn  over. 
They  are  all  stimulant,  in  doses  of  2  to  10 
drops  upon  sugar,  but  are  mostly  made 
into  cordial  waters,  by  distilling  with  spi- 
rit of  wine,  or  water.  The  following  are 
some  of  the  principal,  for  they  consist  of 

2  or  300. 

Oil  of  Wormwood — 25  lbs.  of  green 
wormwood  yielding  from  6  to  10  drs.  of 
this  oil.  Oil  of  Acorns — 50  lbs.  yield  2  oz. 
Essential  oil  of  bitter  Almonds — from 
ground  almond  cake,  by  distillation,  with 
twice  as  much  water  and  half  as  much 
salt,  after  having  been  left  to  soak  for 
some  days,  and  when  half  the  water  is 
come  over,  pouring  it  back  into  the  still : 
25  lbs.  of  cake  yield  2  oz.  and  contains 
prussic  acid ;  when  rectified,  its  strength 
is  prodigiously  increased.  Oil  of  Anue- 
seeds — from  the  seeds ;  congeals  at  62°. 
Oil  of  Star  Anise-seeds — from  the  capsules, 
Very  fragrant.     Oil  of  DUl-seed — Carmi- 


native. Essence  of  Bergamotte — from  the 
peels  of  the  Bergamotte  orange ;  by  pres- 
sure, very  fragrant.  Huile  d'oran-ge — 
from  orange-peel,  by  pressure ;  very  fra- 
grant. Cajeput  oil — from  the  leaves.  Oil 
of  Carui — from  the  seeds,  carminative. 
Oil  of  Gloves — from  cloves,  soaked  and 
distilled  with  salt-water,  the  distilled  wa- 
ter being  returned  two  or  three  times  into 
the  still ;  very  heavy  and  acrimonious. 
Distilled  oil  of  Camomile  Floivers — from 
the  flowers,  stomachic.  Oil  of  Cinnamon 
— from  the  fresh  bark,  distilled  with  sea- 
water.  Rectified  oil  of  Citrons — the  press- 
ed oil  of  the  whole  peels,  distilled  until  3 
oz.  out  of  5  are  come  over,  white,  very 
fragrant.  Oil  of  Cummin-seed — Oil  of 
Hops— Collected  during  the  boiling  of 
hops  in  beer.  Essences  des  Violettes — from 
the  root  of  Florentine  orris ;  smells  like 
violets.  Essence  of  Jasmine — from  the 
flowers  of  Jasminiumgrandiflorum,  high- 
ly fragrant.  Oil  of  Lavender — from  the 
flowers  of  narrow-leaved  lavender,  very 
fine  scented.  OH  of  Spike — from  the 
flowers  and  seeds  of  French  lavender. 
Bectified  oil  of  Lavender — drawing  off  3 
oz.  in  5 ;  used  for  choice  perfumery. 
Biga  Balsam — from  the  shoots  of  Pinus 
cembra,  previously  bruised  and  macerated 
for  a  month  in  water  ;  vulnerary,  diuretic. 
Essence  of  Lemons — from  the  fresh  peels 
of  lemons;  limpid,  watery,  fragrant;  used 
in  perfumery.  Oil  of  Mace — from  that 
spice.  Oil  of  sweet  Marjoram. — Oil  of 
Peppermint — from  the  dried  plant,  4  lbs. 
of  the  fresh  herb  yielded  3  drs. ;  used  to 
flavor  spirit.  Bectijied  oil  of  Peppermint 
— used  for  peppermint  lozenges  ana  drops, 
very  warm.  Oil  of  Milfoil, — 18  baskets 
yield  4  oz.  4  drs.  Essence  of  Myrtle — 
from  the  flowers  and  leaves  ;  fragrant. 
Essence  of  Jonquil — used  in  perfumery. 
Oil  of  Nutmeg — from  that  spice.  Oil  of 
Thyme — from  the  plant,  2  cwt.  fresh  yield 
5i  oz.  stimulant,  makes  the  hair  grow, 
used  in  tooth-ache.  Oil  of  Pimento — 
from  allspice.  Oil  of  Penny-royal — from 
the  herb  when  in  flower.  Oil  of  Bavent- 
sara — from  the  leaves  ;  sold  for  oil  of 
cloves.  Oil  of  Bhodium — from  Levant 
lignum  rhodium :  80  lbs.  yielded  9  drs. 
Oil  of  Boses — from  the  flowers  of  musk 
roses  in  the  cups  split  open,  soaked  in 
twice  their  weight  of  salt-water  for  several 
days,  then  distilled,  and  the  water  eoho- 
bated  once  or  twice  on  them  ;  1  cwt.  yields 
from  half  an  oz.  to  an  oz.  of  oil.  Attar  of 
Boses — from  the  evergreen  rose  and  the 
musk  rose,  the  newly-distilled  rose-water 
being  exposed  to  the  night  air ;  a  highly- 
esteemed  perfume  ;  freezes  at  50°,  mefta 


ole] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


413 


at  85°.  Oil  of  Rosemary— how  the  flow- 
ering tops ;  sweet  scented.  Rectified  oil 
of  Rosemary — by  redistilling  until  one- 
half  is  come  over,  and  used  for  fine  per- 
fumery. Oil  of  Rue — from  the  dried 
plant/ carminative,  antispasmodic.  Oil 
of  Savine— from  the  dried  plant,  stimu- 
lant and  powerfully  emmenagogue ;  ex- 
ternally rubefacient.  Oil  of  Sandal-wood 
— 1  lb." yields  2  drs.  It  is  sold  for  oil  of 
rhodium,  and  oil  of  roses.  Oil  of  Sassa- 
fras—from  the  root  of  sassafras,  with 
salt-water,  and  cohobation.  Oil  of ' Leraon 
Thyme — used  to  scent  soaps.  Oil  of  Tan- 
zey—ixo\r\  the  herb.  Oil  of  Thyme— -2 
cwt.  fresh  flowers  yield  5*  oz.  Oil  of 
Turpentine — from  rough  turpentine  dis- 
tilled with  an  equal  weight  of  water. 

Oil  Mills,  or  Pression  Mills,  are  mov- 
ed by  horse,  or  water  power,  in  Holland 
by  wind,  and  in  England  often,  and  in 
this  country  almost  always,  by  steam. 
The  object  is  to  unite  weight  of  pressure 
with  percussion,  and  therefore  obtain  oil 
from  seeds.  The  principle  is  that  of  the 
pile  engine,  the  falling  with  acceleration 
of  a  heavy  loaded  beam  on  a  bag  of  seed, 
so  placed  as  that  its  oil  will  exude  into 
receptacles  beneath.  A  wheel  called  a 
walloper,  provided  with  wipers,  or  pro- 
jections, is  turned  by  the  spur  and 
treadle,  and  the  wipers  catch  and  lift  the 
beams,  or  pestles,  which  being  unattach- 
ed by  the  rotation  of  the  wheel  fatt  with 
force  on  the  seed,  which  has  usually  been 
rolled  and  expressed  previously.  The  oil 
paste,  or  cakes,  left  alter  pressing,  is  ex- 
cellent food  for  cattle.  The  French  ve- 
getable oils  produce  the  whitest  and 
clearest  light  known,  equal  to  the  best 
carburetted  hydrogen  gas. 

The  quantities  of  volatile  oil,  obtained 
from  different  vegetables,  are : — 

Aniseed 1  lb.      2  drs. 

Assafcetida 4  oz.     1  dr. 

Cajeput  seeds 1  lb.    15  grs. 

Camomile  flowers,  common 1  lb.      \  dr. 

Caraway  seeds 4  lbs.    2  oz. 

Cardamum  seeds 1  oz.     1  scr. 

Cawot  seeds 2  lbs.  If  dr. 

Cinnamon 1  lb.      1  dr. 

Cloves 1  lb.    H  oz. 

Copaiba  balsam  1  lb.      6  oz. 

Cummin  seed 1  lb.      5  drs. 

Dillseed 4  lbs.     2  oz. 

Juniper  berries    8  lbs.     3  oz. 

Lavender,  in  flower,  fresh 48  lbs.   12  oz. 

Mace 1  lb.      5  drs. 

Marjoram,  in  flower,  fresh 85  lbs.  3*  oz. 

Nutmegs 1  lb.      1  oz. 

Roses 1  cwt.  1  oz. 

Rosemary,  in  flower 1  cwt  8  oz. 

Susre  leaves 84  lbs.  \\  oz. 

Sassafras  w  >od 6  lbs.  \\  oz. 


Savin  bark    2  lbs.    5  oz. 

Thyme,  in  flower,  fresh 2  cwt  5£  oz. 

According  to  experiments,  the  follow- 
ing species  of  plants  yield  per  cent,  of 


Filberts 60 

Garden  cress 56  to  58 

Olive 50 

Walnut 50 

Poppy 47  to  50 

Almond 46 

Navew 39 

"White  Mustard 36 

Tobacco  seed 32  to  86 

Kernels  of  plums 33 

"Winter  rape 33 

Summer  rape 30 

Woad 30 

Camelina 28 

Hemp  seed 25 

Fir 24 

Linseed 22 

Black  mustard 18 

Heliotrope 15 

Beech  masts 12  to  16 

Grape  stones 10  to  11 

OIL  OF  VITKOIL,  concentrated  Sul- 
phuric Acid. 

OISANITE.  An  ore  of  Titanium, 
found  in  the  department  Oise,  France. 

OLD  EED  SANDSTONE.  A  series  of 
rocks  interposed  between  the  carbonife- 
rous limestone  and  the  slate.  They  cor- 
respond to  the  Potsdam  sandstone  of  the 
New-York  Geological  Survey  Keport,  are 
chiefly  siliceous,  much  used  for  building 
churches  in  New-York  and  other  cities, 
and  are  highly  interesting  from  the  fossils 
and  fossil  marks  which  are  found  in  them. 

OLEFIANT  GAS.  This  variety  of 
carburetted  hydrogen  is  obtained  by  heat- 
ing a  mixture  of  two  measures  of  sulphu- 
ric acid  and  one  of  alcohol.  It  is  of  some- 
what less  specific  gravity  than  atmosphe- 
ric air,  100  cubic  inches  weighing  30*5  grs. 
It  burns  with  a  bright  white  flame,  and 
produces  during  combustion  such  pro- 
portions of  carbonic  acid  and  water  as 
show  that  1  volume  of  the  gas  is  consti- 
tuted of  2  atoms  or  volumes  of  hydrogen 
and  2  atoms  of  carbon  ;  hence  the  equi- 
valent of  defiant  gas  is  (2  A  + 12  mr.)=14. 
When  two  volumes  of  chlorine  are  mix- 
ed with  1  of  defiant  gas,  and  inflamed, 
hydrocholoric  acid  is  formed,  and  the 
charcoal  of  the  gas  makes  its  appearance 
in  the  form  of  dense  black  soot.  If  the 
mixture,  instead  of  being  kindled,  be  left 
standing  over  water,  it  soon  condenses 
into  a  liquid  looking  like  oil  (hence  the 
term  olejiant  gas),  which  is  hydrochloride 
of  carbon,  it  has  an  aromatic  odor,  not 
unlike  that  of  oil  of  caraways. 
OLEIC  ACID.    The  product  resulting 


414 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[opi 


from  the  action  of  alkalies  upon  the  elaine, 
or  liquid  part  of  oils  and  fats. 

OLEIN,  is  the  thin  oily  part  of  fats  na- 
turally associated  with  glycerine,  marga- 
rine, and  stearine. 

OLEON.  A  peculiar  liquid  obtained 
by  the  distillation  of  a  mixture  of  oleic 
acid  and  lime. 

OL1BANUM.  A  gum  resin,  imported 
from  the  Levant,  in  yellowish-white  and 
nearly  opaque  drops  or  tears ;  it  has  a 
bitterish  flavor,  and  has  been  used  in 
medicine.  When  burned  it  exhales  rather 
an  agreeable  odor,  and  is  sometimes  ca. 
ed  frankincense.  It  is  either  the  produce 
of  the  Junvperus  lycia,  or  of  the  JBoswettia 
serrata. 

It  is  now  only  used  as  incense  in  So- 
man Catholic  churches. 

OLIVE.  (Lat.  olea.)  A  genus  of  trees 
belonging  to  the  Diandria  Monagynia 
class  of  plants.  The  Olea  Europaxi  has 
an  upright  stem,  with  numerous  branches, 
grows  to  the  height  of  twenty  or  thirty 
feet,  and  differs  from  most  trees  in  yield- 
ing a  fixed  oil  from  the  pericarp  instead 
of  from  the  seed.  The  olive  tree  has  in 
all  ages  been  held  in  peculiar  estimation ; 
and  some  authors  have  styled  it  a  "  mine 
upon  earth."  It  was  sacred  to  Minerva. 
Olive  wreaths  were  used  by  the  Greeks 
and  Komans  to  crown  the  brows  of  vic- 
tors ;  and  it  is  still  universally  regarded 
as  emblematic  of  peace.  Tho  olive  flou- 
rishes only  in  warm  and  comparatively 
dry  parts  of  the  world,  as  the  south  of 
France  and  Spain ;  in  Italy,  Syria,  and 
the  north  of  Africa ;  and  though  it  has 
been  raised  in  the  open  air  in  this  coun- 
try, its  fruit  did  not  ripen.  The  fruit  is 
a  smooth  oval  plum,  about  three  quarters 
of  an  inch  in  length,  and  half  an  inch  in 
diameter;  of  a  deep  violet  color  when 
ripe ;  whitish  and  fleshy  within ;  bitter 
and  nauseous,  but  replete  with  a  bland 
oil.    Olives  intended  for  preservation  are 

fathered  before  they  are  ripe.  In  pick- 
ng,  the  object  is  to  remove  and  to  pre- 
serve them  green  by  impregnating  them 
with  a  brine  of  aromatized  sea-salt ;  and 
for  this  purpose  various  methods  are  em- 
ployed. But  it  is  chiefly  for  the  sake  of 
its  oil  that  the  olive  tree  is  cultivated. 
Olive  oil  is  pale  yellow ;  its  density  is  9-10. 
When  fresh,  and  of  fine  quality,  it  is  al- 
most tasteless,  having  only  a  very  slight 
and  agreeable  nutty  flavor.  It  is  less  apt 
than  most  other  fixed  oils  to  become  vis- 
cid by  exposure,  and  hence  is  preferred 
for  greasing  clock  and  watch-work.  It  is 
largely  used  as  an  article  of  food.    It  is 


the  principal  article  of  export  from  the 
kingdom  of  Naples. 

Olive  Oil.     (See  Oils  Fat.) 

OLIVINE.  A  variety  of  Chrysolite  con- 
taining oxide  of  iron  of  an  olive-green  co- 
lor, it  is  sometimes  found  associated  with 
meteoric  iron  and  in  Basalt. 

ONYX.  A  regularly  banded  agate, 
much  prized  for  cameos,  especially  where 
the  colors  are  very  distinct  and  opposed. 
Any  stone  exhibiting  layers  of  two  or 
more  colors  strongly  contrasted  is  called 
an  onyx. 

OOLITE.  A  granular  variety  of  car- 
bonate of  lime,  frequently  calld  roesto-ne. 
The  frequency  of  the  occurrence  of  this 
particular  form  of  limestone  in  a  great  se- 
ries of  deposits,  lying  between  the  sub- 
cretaceous  formations  and  the  new  red 
sandstone,  has  caused  English  geologists 
to  give  the  whole  series  the  name  ot  oli- 
tic.  It  is  largely  developed  in  England 
and  France. 

OPAL.  A  beautiful  mineral  character- 
ized by  its  iridescent  reflection  of  light : 
it  is  very  brittle.  It  consists  of  silica, 
with  about  10  per  cent,  of  water.  Com- 
mon opal  in  some  of  its  characters  resem- 
bles the  preceding ;  but  it  has  no  play  of 
colors,  and  is  abundant,  the  former  being 
a  very  rare  mineral.  Opal  is  found  in 
different  parts  of  Europe,  but  particularly 
in  Hungary  ;  in  the  East  Indies,  &c. 

OPALIZED  WOOD.  Wood  petrified 
by  silica  and  acquiring  a  structure  re- 
sembling common  opal. 

OPIUM.  The  inspissated  juice  of  the 
poppy,  obtained  by  wounding  the  unripe 
seed  capsules  of  the  Papaver  somniferum, 
collecting  the  milky  juice  which  exudes 
and  dries  in  the  sun,  and  kneading  it 
into  cakes.  The  cakes  of  the  best  opium 
are  covered  externally  with  pieces  of  dried 
leaves  and  the  seed  capsules  of  some  spe- 
cies of  Jiumex.  It  should  be  of  a  rich 
brown  color,  tough  consistency,  and 
smooth  uniform  texture  ;  its  peculiar  nar- 
cotic smell  should  be  strong  and  fresh  ; 
its  taste  bitter,  warm,  and  somewhat 
acrid.  The  chemical  analysis  of  opium 
has  rendered  it  probable  that  its  activity 
as  a  medicine  depends  upon  the  presence 
of  a  peculiar  alkaline  base  called  morpliia% 
in  combination  with  an  acid  which  has 
been  termed  neconic  acid.  Opium  also 
contains  narcotine,  narceine,  couein,  gum 
resin,  extractive  matter,  and  small  por- 
tions of  other  proximate  principles. 

The  chief  countries  in  which  opium  is 
prepared  are  India,  Egypt,  Turkey,  and 
other  parts  of  Asia ;  it  is  even  cultivated 


OPl] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


415 


in  Italy,  France,  and  England,  but  the 
climate  of  Europe  seems  to  be  too  uncer- 
tain to  allow  of  its  regular  production. 
Opium  is  pretty  extensively  used,  both  as 
a  masticatory  and  in  smoking,  in  Turkey 
and  India ;  but  its  great  consumption  is 
in  China  and  the  surrounding  countries, 
where  the  habit  of  smoking  it  has  become 
all  but  universal.  The  supplies  for  the 
Chinese  market  are  derived  from  India 
and  Turkey,  but  chiefly  from  the  former. 
Indian  opium  is  distinguished  into  three 
kinds  :  the  Patna  or  that  grown  in  the 
province  of  Bahar,  the  Benares,  and  the 
Malwa  ;  of  which  the  first  is  in  the  high- 
est repute.  The  cultivation  of  opium  in 
India  is  a  strict  government  monopoly. 
Every  one  who  chooses  may,  within  the 
prescribed  regulations,  engage  in  the  opi- 
um cultivation ;  but  the  drug,  when  pre- 
pared, must  all  be  sold  to  thegovernment 
at  a  fixed  price,  which  is  said  to  be  so  far 
from  remunerating  the  growers  that,  were 
it  not  for  the  advances  which  government 
are  obliged  to  make  to  enable  them  to 
carry  on~the  business,  the  cultivation  of 
opium  would  be  discontinued  in  the  great- 
er portion  of  India.  This  monopoly  has 
sometimes  yielded  a  nett  revenue  of  £1,- 
000,000  a  year.  This  revenue  has,  how- 
ever, of  late  years  materially  decreased, 
owing  to  the  introduction  into  China  of 
largesupplies  of  opium  from  Turkey,  into 
which  it  is  found  impossible  to  extend 
the  monopoly.  The  East  India  opium  is 
exported  in  chests  of  159£  lbs.  each. 
The  introduction  of  opium  into  China 
was  a  legitimate  branch  of  traffic  down  to 
the  close  of  the  last  century.  Ever  since 
that  period,  however,  the  trade  has  been 
contraband  ;  but  though  the  Chinese  go- 
vernment has  issued  edict  upon  edict  pro- 
hibiting the  importation  of  the  drug,  the 
consumption  of  Indian  opium  in  China 
has,  in  little  more  than  forty  years,  risen 
from  1,000  to  about  27,000  chests  per  an- 
num. Such  an  extraordinary  increase  in 
a  trade  prohibited  by  law  is  attributable 
only  to  the  corruption  of  the  Chinese  au- 
thorities. At  first  the  trade  was  carried 
on  at  Whampoa,  15  miles  below  Canton  ; 
and  next  at  Macao,  whence  it  was  driven 
by  the  exactions  of  the  Portuguese  ;  and 
the  principal  entrepot  was,  till'  the  recent 
outbreak  of  hostilities  between  the  British 
and  Chinese,  in  the  bay  of  Lintin.  The 
opium  is  kept  on  board  ships,  commonly 
called  receiving  ships,  of  which  there  are 
often  ten  or  twelve  lying  together  at  an- 
chor. The  sales  are  mostly  effected  by 
the  English  and  American  agents  in  Can- 
ton, who  give  orders  for  the  delivery  of 


the  opium ;  which,  on  the  order  being 
produced,  is  handed  over  to  the  Chinese 
smuggler,  who  comes  alongside  at  night 
to  receive  it.  Frequently,'"  however,  the 
smuggler  purchases  the  opium  on  his  own 
account,  paying  for  it  on  the  spot  in  sil- 
ver, it  being  a  rule  of  the  trade  never 
violated  that  the  money  must  be  paid  be- 
fore the  opium  is  delivered.  When  the 
drug  is  landed,  the  laws  are  equally  set  at 
defiance  in  its  progress  through  the  coun- 
try, smoking  houses  being,  it  is  said, 
everywhere  established.  During  the  first 
ten  years  of  the  present  century,  the  ex- 
ports from  India  to  China  were  about 
2,500  chests.  In  1821-1822,  after  the  in- 
troduction of  Malwa  opium  into  the  mar- 
kets of  Bombay  and  Calcutta,  the  exports 
increased  to  4,628  chests ;  and  owing  no 
doubt  to  the  greatly  increased  supply  and 
lower  price  of  the  article,  the  exports  in 
1831-1832  exceeded  20,000  chests,  worth 
more  than  13,000,000  dollars  ;  and  in 
1837-1838  exceeded  30,000  chests,  worth 
20,000,000  dollars. 

In  1839,  the  Chinese  government  en- 
deavored to  stop  the  importation  of  this 
pernicious  drug  into  that  country,  which 
led  to  open  hostilities  and  defeat  on  the 
part  of  the  Chinese  who  were  obliged  to 

?ay  heavily  for  the  expenses  of  the  war. 
'o  raise  this,  an  extra  duty  was  levied  on 
tea  exported,  which  the  English  almost 
wholly  paid,  thus  bearing  the  full  ex- 
penses of  the  war.  The  nefarious  and 
successful  attempt  of  England  to  force  an 
unwilling  trade  on  China  reflects  indelible 
disgrace  upon  that  kingdom. 

Opian  or  narcotine,  and  morphia,  may 
be  well  prepared  by  the  following  pro- 
cess. The  watery  infusion  of  opium  be- 
ing evaporated  to  the  consistence  of  an 
extract,  every  3  parts  are  to  be  diluted 
with  one  and  a  half  parts  in  bulk  of  wa- 
ter, and  then  mixed  in  a  retort  with  20 
parts  of  ether.  As  soon  as  5  parts  of  the 
ether  have  been  distilled  over,  the  narco- 
tic salt  contained  in  the  extract  will  be 
dissolved.  The  fluid  contents  of  the  re- 
tort are  to  be  poured  hot  into  a  vessel 
apart,  and  the  residuum  being  washed 
with  5  other  parts  of  ether,  they  are  to  be 
added  to  the  former.  Crystals  of  narco- 
tine will  be  obtained  as  the  solution  cools. 
The  remaining  extract  is  to  be  diluted  in 
the  retort  with  a  little  water,  and  the  mix- 
ture set  aside  in  a  cool  place.  After  some 
time,  some  narcotine  will  be  found  crys- 
tallized at  the  bottom.  The  supernatant 
liquid  thus  freed  from  narcotine  being  de- 
canted off,  is  to  be  treated  with  caustic 
ammonia  ;   and  the  precipitate  thrown 


416 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ore 


upon  a  filter.  This,  -when  well  washed 
and  dried,  is  to  he  hoiled  with  a  quantity 
of  spirit  of  wine  at  0-84,  equal  to  thrice 
the  weight  of  the  opium  employed,  con- 
taining 6  parts  of  animal  charcoal  for 
every  hundred  parts  of  the  drug.  The 
alcoholic  solution  being  filtered  hot,  af- 
fords, on  cooling,  colorless  crystals  of 
morphia. 

This  alkali  may  he  obtained  by  a  more 
direct  process  without  alcohol  or  ether. 
A  solution  of  opium  in  vinegar,  is  to  be 
precipitated  by  ammonia ;  the  washed 
precipitate  is  to  be  dissolved  in  dilute  mu- 
riatic acid,  the  solution  is  to  be  boiled 
along  with  powdered  bone  black,  filtered, 
and  then  precipitated  by  ammonia.  This, 
when  washed  upon  a  filter  and  dried,  is 
white  morphia,  which  may  be  dissolved 
in  hot  alcohol,  if  fine  crystals  be  wanted. 
(See  Morphia.) 

OPSIOMETER.  An  instrument  for 
measuring  the  extent  of  the  limits  of  dis- 
tinct vision  in  different  individuals,  and 
consequently  for  determining  the  focal 
length  of  lenses  necessary  to  correct  im- 
perfections of  the  eye.  A  contrivance  for 
this  purpose,  by  M.  Lehot,  is  described 
in  the  Notes  by  M.  Qnetelet  to  the  French 
translation  of  HerscheVs  Treatise  on  Light. 
Its  principle  depends  on  the  appearance 
presented  by  a  straight  line  placed  very 
near  the  eye,  in  the  direction  of  its  axis  ; 
and  the  principle  is  carried  into  practice 
by  placing  a  thread  of  white  silk  on  a  nar- 
row rule  covered  with  black  velvet,  and 
furnished  with  a  suitable  apparatus  for 
marking  the  exact  points  at  which  the 
thread  begins  and  ceases  to  be  distinctly 
seen,  when  held  in  a  certain  position  with 
respect  to  the  eye.  An  instrument  for 
the  same  purpose,  on  a  different  principle, 
had  formerly  been  suggested  by  Dr. 
Young. 

ORCIN.  A  crystallizable  coloring  mat- 
ter obtained  from  the  lechen,  Varmlaria 
Orcina. 

ORES.  (Germ,  erze.)  The  mineral 
bodies  from  which  metals  are  extracted. 
Metals  exist  in  the  ores  in  one  or  the 
other  of  the  four  following  states  :  1.  In 
a  metallic  state,  and  either  solitary  or 
combined  with  each  other ;  in  the  latter 
case  forming  alloys.  2.  Combined  with 
sulphur,  forming  sulphurets.  3.  Com- 
bined with  oxygen,  forming  oxides.  4. 
Combined  with  acids,  forming  carbonates, 
phosphates,  <fec,  which  generally  go  by 
the  name  of  metallic  salts. 

Ores  are  very  numerous.    There  are  of 

Antimony 14  Ores. 

Arsenic 10 


Bismuth 5 

Cobalt  12 

Copper 81 

And  so  for  others. 

Certain  ores  which  contain  the  metals 
most  indispensable  to  human  necessities 
have  been  treasured  np  by  the  Creator  in 
very  bountiful  deposits,  constituting 
either  great  masses  in  rocks  of  different 
kinds,  or  distributed  in  lodes,  veins, 
nests,  concretions,  or  beds  with  stony  and 
earthy  admixtures  ;  the  whole  of  which 
become  the  objects  of  mineral  explora- 
tion.' These  precious  stores  occur  in  dif- 
ferent stages  of  the  geological  formations  ; 
but  their  main  portion,  after  having  ex- 
isted abundantly  in  the  several  orders  of 
the  primary  strata,  suddenly  cease  to  be 
found  towards  the  middle  of  the  secon- 
dary. Iron  ores  are  the  only  ones  which 
continue  among  the  more  modern  depo- 
sits, even  so  high  as  the  beds  immedi- 
ately beneath  the  chalk,  when  they  also 
disappear,  or  exist  merely  as  coloring  mat- 
ters of  the  tertiary  earthy  beds. 

The  strata  of  gneiss  and  mica-slate  con- 
stitute in  Europe  the  grand  metallic  do- 
main. There  is  hardly  any  kind  of  ore 
which  does  not  occur  there  in  sufficient 
abundance  to  become  the  object  of  mining 
operations,  and  many  are  found  nowhere 
else.  The  transition  rocks,  and  the  lower 
part  of  the  secondary  ones,  are  not  so 
rich,  neither  do  they  contain  the  same 
variety  of  ores.  But  this  order  of  things, 
which  is  presented  by  Great  Britain, 
Germany,  France,  Sweden,  and  Norway, 
is  far  from  forming  a  general  law ;  since 
in  equinoctial  America  the  gneiss  is  but 
little  metalliferous  ;  while  the  superior 
strata,  such  as  the  clay-schista,  the  sieni- 
tic  porphyries,  the  limestones,  which 
complete  the  transition  series,  as  also  se- 
veral secondary  deposit^  include  the 
greater  portion  of  the  immense  mineral 
wealth  of  that  region  of  the  globe. 

All  the  substances  of  which  the  ordi- 
nary metals  form  the  basis,  are  not  equal- 
ly abundant  in  nature  ;  a  great  proportion 
of  the  numerous  mineral  species  which 
figure  in  our  classifications  are  mere  va- 
rieties scattered  up  and  down  in  the  cavi- 
ties of  the  great  masses  or  lodes.  The 
workable  ores  are  few  in  number,  being 
mostly  sulphurets,  some  oxides,  and  car- 
bonates. These  occasionally  form  of 
themselves  very  large  masses,  but  more 
frequently  they  are  blended  with  lumps 
of  quartz,  felspar,  and  carbonate  of  lime, 
which  form  the  main  body  of  the  deposit; 
as  happens  always  in  proper  lodes.  The 
ores  in  that  case  are  arranged  in  layers 


ore] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


411 


parallel  to  the  strata  of  the  formation,  or 
in  veins  which  traverse  the  rock  in  all 
directions,  or  in  nests  or  concretions  sta- 
tioned irregularly,  or  finally  disseminated 
in  hardly  visible  particles.  These  depo- 
sits sometimes  contain  apparently  only 
one  species  of  ore,  sometimes  several, 
which  must  he  mined  together,  as  they 
seem  to  he  of  contemporaneous  forma- 
tion ;  whilst,  in  other  cases,  they  are  se- 
parable, having  been  probably  formed  at 
different  epochs.  Under  the  particular 
metals  will  be  found  an  account  of  the  lo- 
calities of  ores,  &c. ;  but  the  following 
general  observations  may  prove  useful  in 
presenting  a  condensed  resume  of  the 
whole  subject. 

1.  Tin  exists  principally  in  primitive 
rocks,  appearing  either  in  interlaced  mass- 
es in  beds,  or  as  a  constituent  part  of  the 
rock  itself,  and  more  rarely  in  distinct 
veins.  Tin  ore  is  found,  indeed,  sometimes 
in  alluvial  land,  filling  up  low  situations 
between  lofty  mountains. 

2.  Gold  occurs  either  in  beds  or  in 
veins,  frequently  in  primitive  rocks ; 
though  it  is  also  found  in  other  forma- 
tions, and  particularly  in  alluvial  earth. 
When  this  metal  exists  in  the  bosom  of 
primitive  rocks,  it  is  particularly  ?n 
schists  ;  it  is  not  found  in  serpentine,  but 
it  is  met  with  in  greywacke  in  Transylva- 
nia. The  gold  of  alluvial  districts,  called 
gold  of  washing  or  transport,  occurs,  as 
well  as  alluvial  tin,  among  the  debris  of 
the  more  ancient  rocks. 

3.  Silver  is  found,  particularly  in  veins 
and  beds,  in  primitive  and  transition  for- 
mations ;  though  some  veins  of  this  me- 
tal occur  in  secondary  strata.  The  rocks 
richest  in  it  are  gneiss,  mica-slate,  clay- 
slate,  greywacke,  and  old  alpine  limestone. 
Localities  of  silver-ore  itself  are  not  nu- 
merous, among  secondary  formations  ; 
but  it  occurs  in  combination  with  the  ores 
of  copper  or  of  lead. 

4.  Copper  exists  in  the  three  mineral 
epoch  as :  1.  In  primitive  rocks,  princi- 
pally in  the  state  of  pyritous  copper,  in 
beds,  in  masses,  or  in  veins ;  2.  In  tran- 
sition districts, ^  sometimes  in  masses, 
sometimes  in  veins  of  copper  pyrites  ;  3. 
In  secondary  strata,  especially  in  beds  of 
cupreous  schist. 

5.  Lead  occurs  also  in  each  of  the  three 
mineral  epochas  ;  abounding  particularly  j 
in    primitive    and     transition    grounds,  j 
where  it  usually  constitutes  veins,  and  j 
occasionally  beds    of  sulphuretted    lead  ; 
(galena.)    The  same  ore  is  found  in  strata 
or  in  veins  among  secondary  rocks,  asso- 
ciated now  and  then  with  ochreous  iron-  \ 

18* 


oxide  and  calamine  (carbonate  of  zinc ;) 
and  it  is  sometimes  disseminated  in  grains 
through  more  recent  strata. 

6.  Iron  is  met  with  in  four  different 
mineral  eras,  but  in  different  ores. 
Among  primitive  rocks  magnetic  iron  ore 
and  specular  iron  ore  occur  chiefly  in 
beds,  sometimes  of  enormous  size  :  the 
ores  of  red  or  brown  oxide  of  iron  (hae- 
matite) are  found  generally  in  veins,  or 
occasionally  in  masses  with  sparry  iron, 
both  in  primitive  and  transition  rocks; 
as  also  sometimes  in  secondary  strata ; 
but  more  frequently  in  the  coal-measure 
strata,  as  beds  of  clay-ironstone,  of  glo- 
bular iron  oxide,  and  carbonate  of  iron. 
In  alluvial  districts,  we  find  ores  of  clay- 
ironstone,  granular  iron-ore,  bog-ore, 
swamp-ore,  and  meadow-ore.  The  iron 
ores  which  belong  to  the  primitive  period 
have  almost  always  the  metallic  aspect, 
with  a  richness  amounting  even  to  80  per 
cent,  of  iron,  while  the  ores  in  the  poste- 
rior formations  become,  in  general,  moro 
and  more  earthy,  down  to  those  in  allu- 
vial soils,  some  of  which  present  the  ap- 
pearance of  a  common  stone,  and  afford 
not  more  than  20  per  cent,  of  metal,  though 
its  quality  is  often  excellent. 

7.  Mercury,  as  a  sulphuret,  occurs  prin- 
cipally among  secondary  strata  in  dissem- 
inated masses,  along  with  combustible 
substances  ;  though  the  metal  is  met  with 
occasionally  in  primitive  countries. 

8.  Cobalt  belongs  to  the  three  mineral 
epochas  ;  its  most  abundant  deposits  are 
veins  in  primitive  rocks  ;  small  veins  con- 
taining this  metal  are  found,  however,  in 
secondary  strata. 

9.  Antimony  occurs  in  veins  or  beds 
among  primitive  and  transition  rocks. 

10.  Bismuth  and  nickel  do  not  appear 
to  constitute  the  predominating  substance 
of  any  mineral  deposits ;  but  they  often 
accompany  cobalt. 

11.  Zinc  occurs  in  the  three  several  for- 
mations ;  namely,  as  sulphuret,  or  blende, 
particularly  in  primitive  and  transition 
rocks  ;  as  calamine,  in  secondary  strata, 
usually  along  with  oxide  of  iron,  and 
sometimes  with  sulphuret  of  lead. 

In  the  analysis  of  ores,  it  is  impossible 
to  lay  down  any  general  rule,  so  numer- 
ous are  the  ores  themselves,  and  so  di- 
versified the  means  necessary  to  be  adopt- 
ed in  the  various  analytic  processes.  Un- 
der each  particular  metal  will  be  found  an 
account  of  its  most  important  ores,  and 
we  shall  here  restrict  ourselves  to  a  few 
general  remarks  on  the  theory  of  smelting 
ores. 

It  is  probable  that  the  coaly  matter  em- 


418 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[ORP 


ployed  in  that  process  is  not  the  immedi- 
ate agent  of  their  reduction ;  hut  the  char- 
coal seems  first  of  all  to  be  transformed 
by  the  atmospherical  oxygen  into  the  ox- 
ide of  carbon,  which  gaseous  product  then 
surrounds  and  penetrates  the  interior  sub- 
stance of  the  oxides,  with  the  effect  of  de- 
composing^ them,  and  carrying  off  their 
oxygen.  That  this  is  the  true  mode  of 
action,  is  evident  from  the  well-known 
facts  that  bars  of  iron,  stratified  with 
pounded  charcoal,  in  the  steel- cementa- 
tion chest,  most  readily  absorb  the  car- 
bonaceous principle  to  their  innermost 
centre,  while  their  surfaces  get  blistered 
by  the  expansion  of  carburetted  gases 
formed  within ;  and  that  an  intermixture 
of  ores  and  charcoal  is  not  always  neces- 
sary to  reduction,  but  merely  an  inter- 
stratification  of  the  two,  without  intimate 
contact  of  the  particles.  In  thi3  case,  the 
carbonic  acid  which  is  generated  at  the 
lower  surfaces  of  contact  of  the  strata, 
rising  up  through  the  first  bed  of  ignited 
charcoal,  becomes  converted  into  carbonic 
oxide ;  and  this  gaseous  matter,  passing 
up  through  the  next  layer  of  ore,  seizes 
its  oxygen,  reduces  it  to  metal,  and  is  it- 
Belf  thereby  transformed  once  more  into 
carbonic  acid  ;  and  so  on  in  continual  al- 
ternation. It  may  be  laid  down,  however, 
its  a  general  rule,  that  the  reduction  is  the 
more  rapid  and  complete  the  more  inti- 
mate the  mixture  of  the  charcoal  and  the 
metallic  oxide  has  been,  because  the  for- 
mation of  both  the  carbonic  acid  and  car- 
bonic oxide  becomes  thereby  more  easy 
and  direct.  Indeed  the  cementation  of 
iron  bars  into  steel  will  not  succeed,  un- 
less the  charcoal  be  so  porous  as  to  con- 
tain, interspersed,  enough  of  air  to  favor 
the  commencement  of  its  conversion  into 
the  gaseous  oxide ;  thus  acting  like  a  fer- 
ment in  brewing.  Hence,  also,  finely 
pulverized  charcoal  does  not  answer  well, 
unless  a  quantity  of  ground  iron  cinder  or 
oxide  of  manganese  be  blended  with  it, 
to  afford  enough  of  oxygen  to  begin  the 

feneration  of  carbonic  oxide  gas  ;  where- 
y  the  successive  transformations  into 
acid  and  oxide  are  put  in  train. 

Iron  is  the  most  abundant  of  ores  our 
country  affords.  Its  value  is  ten  times 
that  of  gold  and  silver,  and  one  half  the 
value  01  all  the  metals  produced  in  the 
United  States.  Iron  is  found  in  every 
State  of  the  Union. 

The  most  valuable  mine  is  one  in  Salis- 
bury, Ct.,  which  yields  8,000  tons  annu- 
ally. The  mines  in  Duchess  and  Colum- 
bia counties,  in  the  State  of  New- York, 
produce  20,000  tons  of  ore ;  Essex  county, 


1,500  tons ;  Clinton,  3,000 ;  Franklin,  600; 
St.  Lawrence,  2,000 ;  amounting  in  all  to 
more  than  $500,000.  The  value  of  the 
iron  produced  in  the  United  States,  in 
1835,  was  $5,000,000 ;  in  1837,  $7,700,000. 

In  Ohio,  1,200  square  miles  are  under- 
laid with  iron.  A  region  explored  in 
1838  would  furnish  iron  sixty-one  miles 
long,  and  six  miles  wide ;  a  square  would 
yield  3,000,000  tons  of  pig-iron  ;  so  that 
this  district  would  contain  1,000,000,000 
tons.  By  taking  from  this  region  400,000 
tons  annually,  (a  larger  quantity  than 
England  produced  previous  to  1829,)  it 
would  last  2,700  years — as  long  a  distance, 
certainly,  as  any  man  looks  ahead !  In 
the  States  of  Kentucky  and  Tennessee, 
100,000  tons  are  annually  manufactured. 

The  most  extensive  lead  mines  in  the 
world  are  in  Missouri,  where  the  lead  re- 
gion is  seventy  miles  long  by  fifty  wide. 
These  mines  in  1826,  produced  7,500,000 
tons,  and  the  whole  produce  of  the  United 
States  was  8,322,105. 

The  quantity  of  lead  manufactured  in 
the  United  States,  in  1828,  was  12,311,730 
lbs.;  in  1829,  14,541,310  lbs.;  in  1838, 
8,332,105;  and  in  1842,  4,281,687. 

The  copper  trade,  until  within  a  year 
or  two,  has  not  been  of  much  importance, 
as  the  results  of  the  efforts  made  were 
not  such  as  to  justify  any  great  opera- 
tions. But  now  it  appears  to  be  attract- 
ing a  good  deal  of  attention.  Whether 
the  demand  of  the  copper  stock  is  a  fair 
index  to  the  value  of  the  copper  regions 
remains  to  be  seen. 

OKPIMENT  occurs  in  indistinct  crys- 
talline particles,  and  sometimes  in  oblique 
rhomboidal  prisms ;  but  for  the  most 
part,  in  kidney  and  other  imitative  forms ; 
it  has  a  scaly  and  granular  aspect ;  tex- 
ture foliated,  or  radiated ;  fracture  small 
granular,  passing  into  conchoidal ;  splin- 
tery, opaque,  shining,  with  a  weak  dia- 
mond lustre;  lemon,  orange,  or  honey 
yellow ;  sometimes  green ;  specific  grav- 
ity, 3-44  to  3-6.  It  is  found  in  floetz 
rocks,  in  marl,  clay,  sandstone,  along 
with  realgar,  lead-glance,  pyrites,  and 
blende,  in  many  parts  of  the  world.  It 
volatilizes  at  the  blowpipe.  It  is  used  as  a 
pigment,  and  is  a  yellow  sulphuret  of  ar- 
senic. 

The  finest  specimens  come  from  Persia, 
in  brilliant  yellow  masses,  of  a  'amellar 
texture,  called  golden  orpiment. 

Artificial  orpiment  is  manufactured 
chiefly  in  Saxony,  by  subliming  in  cast- 
iron  cucurbits,  surmounted  by  conical 
cast-iron  capitals,  a  mixture  in  due  pro- 
portions of  sulphur  and  arsenious  acid 


oxa] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


419 


(white  arsenic).    As  thus  obtained,  it  is  i 
in  yellow  compact  opaque  masses,  of  a  j 
glassy  aspect ;   affording  a  powder  of  a  j 
pale  yellow  color.     Genuine  orpiment  is  | 
often  adulterated  with  an  ill-made  com-  j 
pound;  which   is  sold  in   England    by  ! 
the  preposterous  name  of  king's  yellow. 
This  fictitious  substance  is  frequently  no- 
thing else  than  white  arsenic  combined 
with  a  little  sulphur ;  and  is  quite  soluble 
in  water.    It  is  therefore  a  deadly  poison. 

The  first  kinds  of  native  orpiment  are 
reserved  for  artists  ;  the  inferior  are  used 
for  the  indigo  vat.  They  are  all  soluble 
in  alkaline  leys,  and  in  water  of  ammonia. 

ORRIS  ROOT.  The  root  of  the  Iris 
Florentine.  It  has  an  agreeable  odor, 
much  like,  violets,  and  is  sometimes  used 
in  perfumed  powders ;  it  is  also  turned 
into  little  balls  for  issues,  called  or?<is  peas. 

ORTHITE.  A  mineral  which  occurs 
in  straight  rays  or  layers  in  Scandinavian 
granite.     It  contains  cerium  and  yttria. 

OSCILLATION.  In  mechanics,  the 
vibration  or  alternate  ascent  and  descent 
of  a  pendulous  body.  The  centre  of  os- 
cillation is  a  point  in  the  oscillating  body, 
such  that  if  all  the  matter  of  the  body 
were  there  collected,  the  oscillations 
would  be  performed  in  the  same  time. 
The  axis  of  oscillation  is  a  straight  line 
passing  through  the  point  of  suspension 
parallel  to  the  horizon,  or  perpendicular 
to  the  plane  in  which  the  oscillation  is 
made.  Oscillations  in  small  arcs  of  a 
circle,  or  in  cycloidal  arcs  of  any  length, 
are  isochronal  or  performed  in  equal  times. 

OSMAZOME.  The  extractive  matter 
of  muscular  fibre,  which  gives  the  pecu- 
liar smell  to  boiled  meat,  and  flavor  to 
broth  and  soup. 

OSMIUM.  A  metallic  substance  found 
associated  with  the  ore  of  platinum ;  its 
peroxide  is  extremely  volatile,  and  has  a 
peculiar  pungent  odor,  which  suggested 
the  name  of  the  metal :  from  007*17  odor. 
Neither  osmium  nor  its  compounds  have 
been  applied  to  any  use,  and  it  is  a  rare 
substance. 

OTTAR,  or  OTTAR  OF  ROSES.  The 
volatile  or  odorous  oil  of  the  rose  :  it  is  of 
a  soft,  buttery  consistence,  and  deposits, 
when  fluid,  a  crystallizable  portion,  which 
is  sparingly  soluble  in  alcohol :  it  is  much 
used  as  a  perfume.  The  finest  ottar  of 
roses  is  prepared  at  Ghazedpore  in  India. 

OXALATES.    Salts  of  the  oxalic  acid. 

OXALIC  ACID.  A  vegetable  acid, 
first  discovered  in  the  juice  of  the  Oxalis 
acetoseUa  ;  it  was  afterwards  ascertained 
that  the  same  acid  might  be  produced  ar- 
tificially by  the  action  of  the  nitric  acid 


upon  sugar ;  this  process  yields  it  in  slen- 
der prismatic  crystals,  intensely  sour, 
and  soluble  in  about  ten  parts  of  cold  wa- 
ter. These  crystals  consist  of  1  atom  of 
real  acid,  and  3  of  water:  the  equivalent 
of  the  acid  is  36 ;  and  in  its  anhydrous 
state,  as  it  exists  in  the  dry  oxalates,  it 
is  constituted  of  2  atoms  of  carbon  (6X2) 
=12,  and  3  of  oxygen  (8X3)=24  :  so  that 
it  may  be  represented  by  an  atom  of  car- 
bonic acid  and  one  of  carbonic  oxide. 
Solutions  of  oxalic  acid,  or  of  soluble  ox- 
alates, yield  an  insoluble  precipitate  in 
solutions  containing  lime  and  its  salts : 
hence  its  use  in  the  laboratory  as  a  test 
of  the  presence  of  that  earth.  The  solu- 
tion or  oxalate  of  ammonia  is  generally 
used  for  the  purpose.     Oxalic  acid  is  a 

Eowerful  poison,  and,  from  its  resem- 
lance  to  Epsom  salt,  it  has  sometimes 
been  sold  and  mistaken  for  that  harmless 
aperient.  In  such  cases,  the  best  anti- 
dote is  a  mixture  of  ci.flk  and  water,  and 
where  it  is  immediately  administered  it 
generally  prevents  the  accession  of  fatal 
symptoms :  it  forms  an  insoluble  oxalate 
of  lime,  which  is  inert. 

It  is  usually  prepared  upon  the  small 
scale  by  digesting  four  parts  of  nitric  acid 
of  specific  gravity  1-4,  upon  one  part  of 
sugar  in  a  glass  retort;  but  on  the  large 
scale,  in  a  series  of  salt-glazed  stoneware 
pipkins,  two  thirds  filled,  and  set  in  a 
water  bath.  The  addition  of  a  little  sul- 
phuric acid  has  been  found  to  increase 
the  product.  15  pounds  of  sugar  yield 
fully  17  pounds  of  the  crystalline  acid. 
This  acid  exists  in  the  juice  of  wood  sor- 
rel, the  oxalis  acetosella,  in  the  state  of  a 
bioxalate ;  from  which  the  salt  is  extract- 
ed as  an  object  of  commerce  in  Switzer- 
land, and  sold  under  the  name  of  salt  of 
sorrel,  or  sometimes,  most  incorrectly, 
under  that  of  salt  of  lemons. 

Some  prefer  to  make  oxalic  acid  by  act- 
ing upon  4  parts  of  sugar,  with  24  parts 
of  "nitric  acid  of  specific  gravity  1*220,  heat- 
ing the  solution  in  a  retort  till  the  acid 
begins  to  decompose,  and  keeping  it  at 
this  temperature  as  long  as  nitrous  gas  is 
disengaged.  The  sugar  loses  a  portion 
of  its  carbon,  which,  combining  with  the 
oxygen  of  the  nitric  acid,  becomes  car- 
bonic acid,  and  escapes  along  with  the 
deutoxide  of  nitrogen.  The  remaining 
carbon  and  hydrogen  of  the  sugar  being 
oxidized  at  the  expense  of  the  nitric  acid, 
generate  a  mixture  of  two  acids,  the  ox- 
alic and  the  malic.  Whenever  gas  ceases 
to  issue,  the  retort  must  be  removed  from 
the  source  of  heat,  and  set  aside  to  cool ; 
the  oxalic  acid  crystallizes,  but  the  malig 


420 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[oxi 


remains  dissolved.  After  draining  these 
crystals  upon  a  filter  funnel,  if  the  brown- 
ish liquid  be  further  evaporated,  it  will 
furnish  another  crop  of  them.  The  re- 
siduary mother  water  is  generally  regard- 
ed as  malic  acid,  but  it  also  contains  both 
oxalic  and  nitric  acids ;  and  if  heated 
with  6  parts  of  the  latter  acid,  it  will 
yield  a  good  deal  more  oxalic  acid  at  the 
expense  of  the  malic.  The  brown  crystals 
now  formed  being,  however,  penetrated 
with  nitric,  as  well  as  malic  acid,  must  be 
allowed  to  dry  and  effloresce  in  warm  dry 
air,  whereby  the  nitric  acid  will  be  got 
rid  of  without  injury  to  the  oxalic.  A 
second  crystallization  and  efflorescence 
will  entirely  dissipate  the  remainder  of 
the  nitric  acid,  so  as  to  afford  pure  oxalic 
acid  at  the  third  crystallization.  Sugar 
affords,  with  nitric  acid,  a  purer  oxalic 
acid,  but  in  smaller  quantity,  than  saw- 
dust, glue,  silk,  hairs,  and  several  other 
animal  and  vegetable  substances. 

Oxalic  acid  occurs  in  aggregated  prisms 
when  it  crystallizes  rapidly,  but  in  tables 
of  4  and  6  sides  when  crystallized  more 
slowly. 

OXIDE.  Compounds  containing  oxy- 
gen, but  which  are  not  acid,  have  been 
termed  oxides.  The  metallic  oxides  are  a 
most  important  class  of  bodies.  To  desig- 
nate the  different  oxides  of  one  base  we 
generally  use  the  first  syllable  of  the  Greek 
ordinal  numerals,  designating  the  first,  se- 
cond, third,  &c,  oxides  by  the  terms  pro- 
toxide, deutoxide,  tritoxiie,,  &c. ;  and  when 
the  base  is  saturated  with  oxygen,  (still 
not  acid)  it  is  termed  a  peroxide.  Com- 
pounds of  bases  with  one  atom  and  a  half 
oxygen,  or  of  two  base  and  three  oxygen, 
are  now  generally  distinguished  by  the 
term  sesquioxides.  Deutoxides  and  trit- 
oxides  are  commonly  called  binoxides  and 

OXYGEN.  This  important  element 
was  discovered  in  1774,  by  Dr.  Priestly. 
It  has  been  termed  dephlogisticated  air, 
vital  air,  and  empyreal  air.  As  it  forms 
a  component  part  of  many  of  the  acids,  it 
was  termed,  at  the  framing  of  the  new 
nomenclature,  oxygen  gas.  There  are 
several  compounds  of  oxygen,  which, 
when  exposed  to  heat,  are"  decomposed, 
and  yield  the  gas  in  a  state  of  purity  :  of 
these  the  best  is  chlorate  of  potash  :  but 
as  that  salt  is  expensive,  we  generally  re- 
sort to  black  oxide  of  manganese,  which, 
at  a  dull-red  heat,  gives  out  a  consider- 
able quantity  of  tolerably  pure  oxygen 
gas.  Oxide  of  manganese,  or  bichromate 
of  potass,  heated  with  sulphuric  acid, 
gives  out  oxygen. 


Oxygen  gas  is  colorless,  tasteless,  and 
inodorous;  it  is  electro-negative,  and 
therefore,  when  compounds  containing  it 
are  electrically  decomposed,  it  always  ap- 
pears at  the  positive  surface.  It  is  a  lit- 
tle heavier  than  atmospheric  air,  in  the 
proportion,  that  is,  of  11  to  10;  100  cub- 
ical inches  weighing  34-6  grains.  It  is 
not  absorbed  by  water,  and  is  neither 
acid  nor  alkaline.  It  has  a  powerful  at- 
traction for  most  of  the  simple  substances, 
especially  for  the  electro-positive  bodies : 
the  act  of  combining  with  it  is  called  ox- 
idation. The  compounds  thus  formed 
are  divided  into  acids  and  oxides :  among 
the  latter  are  the  alkalies,  and  almost  all 
salifiable  bases.  Oxidation  is  often  attend- 
ed with  the  evolution  of  heat. and  light, 
as  in  all  processes  of  combustion  in  at- 
mospheric air :  sometimes  it  is  slow,  and 
unattended  with  such  phenomena,  as  in 
the  gradual  rusting  of  metals.  Oxygen  is 
a  most  powerful  supporter  of  combustion ; 
it  constitutes  one  fifth  of  the  bulk  of  the 
atmosphere,  and  is  the  principle  which 
enables  combustible  bodies  to  burn  in  it. 
The  product  of  combustion,  that  is,  the 
oxide  or  acid,  is  sometimes  itself  gaseous, 
as  when  charcoal,  by  burning,  is  convert- 
ed into  carbonic  acid ;  or  it  is  liquid,  as 
hydrogen,  by  combustion,  produces  wa- 
ter; or  it  is  solid,  as  when  iron,  by  burn- 
ing, produces  oxide  of  iron.  Oxygen  gas 
is  also  essential  to  respiration ;  that  is, 
to  the  evolution  of  carbonic  acid  from  the 
blood. 

OXIDATION  OF  METALS  is  effect- 
ed either  by  the  air  and  heat,  by  burning 
with  nitrate  of  potash,  by  water,  by  acid- 
ulous solution,  the  excess  of  acid  being 
subsequently  withdrawn  by  an  alkali,  or 
other  substance  of  greater  affinity. 

Oxidation  renders  metals  susceptible  of 
the  action  of  acids,  and  hence  their  va- 
riety of  salts.  If  the  metal  becomes  a 
salt,  it  was  previously  an  oxide,  or  was 
oxidized  in  the  process. 

To  oxidize  metals,  after  they  are  melt- 
ed they  are  exposed  in  the  furnace  in  a 
flat  dish,  and  stirred.  Zinc  and  mercury 
vaporize  and  require  one  to  be  exposed 
to  air  previously,  and  the  other  in  a  long- 
necked  vessel,  that  it  may  not  wholly 
escape,  and  yet  rise  to  contact  with  air. 

After  metals  are  melted  and  burned 
they  form  oxides,  8  of  which  are  white; 
iron,  lead,  copper,  manganese,  and  mer- 
cury, which  are  red,  or  black,  or  yellow. 
Silver,  too,  is  olive,  and  antimony  yellow. 
Further  heat  converts  these  powders  into 
glass,  aud  they  are  generally  soluble  in 
acids  or  alkalies.    Heated  with  charcoal, 


PAl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


421 


carburet  of  iron,  oil,  &c,  they  may  be 
restored  to  the  metallic  form. 

Iron  combines  with  28*75  and  48-12  of 
oxygen  in  100,  to  form  its  black  and  red 
oxide. 

Zinc  with  24-24. 

Arsenic  with  34-93  and  52-4. 

Manganese  with  28-75  and  57*5. 

Bismuth  with  11-28. 

Antimony  18*6. 

Copper  1 2-5  for  red,  and  2-5  for  blaek. 

Silver  7-272. 

Mercury  4  for  black,  and  8  for  red. 

Lead  11-53  for  red,  and  15-384  for 
brown. 

The  alkaline  metals  absorb  still  more  : 
magnesium  66*6,  sodium,  33-3,  calcium 
38-39,  potassium  20,  and  barium  11-42 
all  white. 

Gold  affords  2  chemical  oxides,  and  its 
leave*  are  changed  to  purple  color  by 
electricity. 

PACKING  is  the  means  by  which  the 
working  parts,  as  the  rods  and  pistons, 
of  steam-engines,  pneumatic,  and^  hy- 
draulic apparatus,  are  made  steam,  air  or 
water  tight.  It  sometimes  consists  of 
hemp,  cotton,  India-rubber,  or  other  com- 
pressible or  elastic  material,  and  is  then 
termed  soft  packing.  This  is  made  to  em- 
brace the  rod,  or  tit  the  cylinder  tightly, 
by  the  pressure  of  tightening  screws.  The 
above  kind  of  packing  is,  however,  al- 
most superseded  by  metal  packing,  which 
consists  of  rings  or  segments  of  metal 
having  springs"  or  other  elastic  media 
applied  to  them,  to  keep  them  close  or 
binding  on  the  rod,  or  within  the  cylin- 
der. The  advantages  of  the  metal  13,  that 
it  does  not  frequently  require  renewing. 

PACKFONG.  The  Chinese  name  of 
the  alloy  of  nickel  and  copper  commonly 
called  German  silver.  It  is  an  alloy  of  7 
parts  of  zinc,  2-5  copper,  and  6-5  nickel. 

PACOS.  The  Peruvian  name  of  an 
earthy-looking  ore,  which  consists  of 
brown  oxide  of  iron,  with  imperceptible 
particles  of  native  silver  disseminated 
through  it. 

PADDING,  in  calico-printing,  is  the 
impregnation  of  the  cloth  with  a  mordant. 

PADDLE.  A  kind  of  oar  used  by 
savage  nations  in  navigating  their  canoes. 
The  paddle  is  broader  at  the  end  than 
the  common  oar ;  and  being  employed  at 
the  stern  of  the  canoe,  not  only  impels 
her  forwards,  but  regulates  her  course 
exactly  like  a  rudder. 

PADDLE-WHEELS  are  the  rotating 
levers  with  which  steam  or  other  power 
acts  against  water,  in  propelling  a  vessel. 
The  idea  is  not  new,  for  rotating  paddles 


were  turned  by  oxen,  &c,  in  the  Middle 
Ages.  Many  patent  improvements  and 
varieties  of  form  have  been  proposed ; 
the  chief  object  is  to  keep  them  vertical  to 
the  water,  and  this  has  been  effected  by 
an  extra  arm,  worked  by  cranks,  in  con- 
nection with  the  pivot  of  the  float-boards, 
which  turn  on  the  arms. 

It  has  been  proposed  to  work  paddles 
by  sails,  in  certain  cases,  especially  when 
any  accident  befalls  the  boiler  of  works 
of  the  engine. 

Woodcraft  proposes  to  make  paddles  of 
spiral  vanes,  with  increasing  angles  of  in- 
clination with  the  .axis  and  increasing  dis- 
tance, and  has  taken  out  a  patent  for  the 
idea. 

PAINT,  Use  of.  It  is  not  an  uncom- 
mon thing  for  some  paints,  especially 
when  exposed  to  the  atmosphere,  to  rub 
off  like  whitewash,  after  they  have  been 
put  on  for  about  six  or  eight  months. 
We  have  known  white  paint  do  this,  al- 
though both  the  oil  and  white  lead  were 
said  to  be  good.  In  respect  to  white 
paint,  which  is  most  extensively  used, 
there  are  three  things  which  may  be  the 
causes  of  its  inferiority  and  rubbing  off. 
These  are  bad  oil,  bad  lead,  and  too  much 
turpentine.  The  best  linseed  oil  only 
should  be  used,  and  it  should  be  boiled, 
but  not  too  long  nor  at  too  great  a  heat. 
Linseed  oil  is  frequently  adulterated  with 
sun-flower  oil,  which  is  very  inferior  to 
that  of  linseed. 

Sometimes  white  lead  is  sold  which  is 
very  inferior  to  others,  but  painters  know 
how  to  judge  between  the  good  and  bad. 
The  best  can  easily  be  ascertained  by 
painters  from  the  quantity  of  oil  required 
to  give  it  proper  consistency.  In  mixing 
paints,  there  should  be  no  turpentine  at 
all  used  for  outside  work  (at  most  the 
smallest  possible  quantity),  because  the 
turpentine  makes  a  soap  of  the  oil,  conse- 
quently, it  soon  will  rub  off  or  be  washed 
away  by  storms,  &c.  The  only  benefit 
of  boiling  linseed  oil  is  to  drive  away  its 
moisture,  and  ammonia,  so  that  the  glu- 
ten of  the  oil  will  form  a  beautiful  skin 
or  varnish,  when  dry,  to  protect  the  lead 
from  the  effects  of  the  atmosphere. 
While  turpentine  forms  a  good  varnish 
with  resins  and  gums,its  combination  with 
oil  is  altogether  different,  forming  a  soap; 
hence  those  who  know  not  this  fact,  and 
use  too  much  turpentine  with  their  paints 
for  outside  work,  may  expect  to  see  it  dis- 
appear before  it  is  very  old.  The  best  way 
to  put  on  white  lead  for  outside  work,  is 
to  commence  with  a  very  thin  coat,  and 
let  it  dry  perfectly.    It  is  better  to  put  on 


422 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PA7 


four  thin  coats,  one  after  another,  than 
two  thick  ones.  The  labor,  to  be  sure,  is 
more  expensive,  but  those  who  buy  their 
own  paint,  and  use  it  in  the  country,  will 
find  out  that  it  will  be  a  saving  in  the 
end. 

In  painting  woodwork,  the  first  opera- 
tion consists  in  killing  the  knots,  from 
which  the  turpentine  would  otherwise 
exude  and  spoil  the  work.  To  effect  this, 
the  knots  are  covered  with  fresh  slakca 
lime,  which  dries  up  and  burns  out  the 
turpentine.  When  this  has  been  on 
twenty-four  hours,  it  is  scraped  off,  and 
the  knots  painted  over  with  a  mixture  of 
red  and  white  lead,  mixed  with  glue  size. 
After  this  they  are  gone  over  a  second 
time  with  red  and  white  lead,  mixed 
with  linseed  oil.  When  dry  they  must 
be  rubbed  perfectly  smooth  with  pumice 
stone,  and  the  work  is  ready  to  receive 
the  priming  coat.  This  is  composed  of 
red  and  white  lead,  well  diluted  with  lin- 
seed oil.  The  nail  holes  and  other  imper- 
fections are  then  stopped  with  putty,  and 
the  succeeding  coats  are  laid  on,  the  work 
being  rubbed  down  between  each  coat, 
to  bring  it  to  an  even  surface.  The  first 
coat  after  the  priming  is  mixed  with  lin- 
seed oil  and  a  little  turpentine.  In  laying 
on  the  second  coat,  where  the  work  is 
not  to  be  finished  white,  an  approach 
must  be  made  to  the  required  color. 
The  third  coat  is  usually  the  last,  and  is 
made  with  a  base  of  white  lead,  mixed 
with  the  requisite  color,  and  diluted  with 
one  third  of  linseed  oil  to  two  thirds  of 
turpentine,  for  inside. 

Painting  on  stucco,  and  all  other  work 
in  which  the  surface  is  required  to  be 
without  gloss,  has  an  additional  coat 
mixed  with  turpentine  only,  which,  from 
its  drying  of  one  uniform  fiat  tint,  is  call- 
ed a  flatting  coat. 

If  the  knots  show  through  the  second 
coat,  they  must  be  carefully  covered  with 
silver  leaf. 

Work  finished  as  above  described 
would  be  technically  specified  as  knotted, 
primed,  painted  S  oils,  and  flatted. 

Flatting  is  almost  indispensable  in  all 
delicate  interior  work,  but  it  is  not  suited 
to  outside  work,  as  it  will  not  bear  expos- 
ure to  the  weather. 

Painting  on  stucco  is  primed  with 
boiled  linseed  oil,  and  should  then  receive 
at  least  three  coats  of  white  lead  and  oil, 
and  be  finished  with  a  flat  tint.  The 
great  secret  of  success  in  painting  stucco 
is,  that  the  surface  should  be  perfectly 
dry ;  and,  as  this  can  hardly  be  the  case 
in 'less  than  two  years  after  the  erection 


of  a  building,  it  will  always  be  advisable 
to  finish  new  work  in  distemper,  which 
can  be  washed  off  whenever  the  walls  are 
sufficiently  dry  to  receive  the  permanent 
decorations. 

PAINT,  New  White.  Two  varieties 
of  white  are  now  in  the  market  as  a  sub- 
stitute for  lead.  One  is  the  white  oxide 
or  the  sesquioxide  of  antimony,  which 
was  lately  brought  into  notice  in  France, 
and  has  been  much  used  in  England.  It 
does  not  darken  by  exposure  to  air  or 
sulphuretted  vapors,  and  nas  a  good  body : 
it  is  also  cheaper  than  white  lead.  The 
other  variety  has  been  brought  into  no- 
tice here  by  the  New  Jersey  Zinc  Manu- 
facturing Company,  who  have  prepared 
the  flowers  or  white  oxide  of  zinc  for  that 
purpose.  It  is  a  cheap  and  harmless 
paint,  does  not  alter  or  blacken  like  lead, 
but  it  does  not  appear  in  itself  to  have 
sufficient  body  to  recommend  its  exten- 
sive use. 

PAINTING  HOUSEWORK  is  effected 
for  the  most  part  by  priming,  and  then 
applying  two  or  three  coats  of  white  lead 
or  ceruse,  in  linseed  oil.  Colors  are  add- 
ed at  pleasure,  of  lamp-black,  red  lead  or 
ochres,  or  pigments. 

Priming,  used  by  painters  for  new 
woodwork,  is  a  thin  solution  of  white 
and  red  lead  in  linseed  oil. 

Flexible  Paint.  (For  Canvas.)  In  a 
hot  soap  ley,  of  water  6  lbs.,  and  soap  1 
lb.,  stir  well  112  lbs.  of  oil  paint,  and  use 
while  warm. 

Relief.  London  painters  produce  strik- 
ing relief  in  inscriptions.  The  moin  sur- 
face is  .erold,  as  a  middle  tint.  The  strong 
light  of  yellow  ochre  and  white  is  placed 
at  the  side,  and  the  upper  and  under  part 
is  in  warm  shade.  A  very  strong  sha- 
dow is  seen  under  this,  upon  the  rose- 
wood, which  makes  the  warm  shade  ap- 
pear as  a  reflected  light,  and  a  fainter 
shadow  is  put  in  beyond  this.  The 
effect  is  so  masterly,  that  it  is  difficult 
to  tell  whether  the'  letters  are  raised  or 
not. 

White  Paint.  Skim  milk  2  qts. ;  fresh 
slaked  lime  8  oz. ;  linseed  oil  6  oz. ;  whito 
Burgundy  pitch  2  oz. ;  Spanish  white  3 
lbs.  The  lime  must  bo  slaked  in  water, 
exposed  to  the  air,  mixed  in  about  one 
fourth  of  the  milk;  the  oil  in  which  the 
pitch  is  previously  dissolved  must  be 
added  gradually,  then  the  rest  of  the 
milk,  and  afterwards  the  Spanish  white. 
This  quantity  is  sufficient  for  27  square 
yards,  two  coats,  and  the  expense  not 
more  than  lOd. 

Spanish  White  is  made  by  grinding  fine 


•al] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


423 


jhalk  with  1-1  Oth  of  alum  in  water,  shak- 
\ng  and  drying  in  the  air  and  then  in  fire. 

Cheap  Paint.  Gas-tar  mixed  with  yel- 
low ochre  makes  an  excellent  green  paint, 
well  adapted  for  preserving  coarse  wood- 
work and  iron  rails. 

PAINTING  ON  GLASS  is  effected 
chiefly  by  colors  derived  from  metals. 
The  colors  are  laid  on  by  fluxes,  as  soft 
glass,  and  easily  vitrified  bodies.  The 
colors  are  fixed  by  annealing  the  metals 
to  the  glass.  The  glass  used  is  crown- 
glass.  The  annealing  is  performed  in  a 
kiln  built  for  the  purpose.  The  fluxes 
are  minium,  calcined  borax,  salt,  and 
powdered  flint-glass.  Gold  produces 
the  splendid  ruby  color.  Silver,  a  yellow. 
Copper,  a  red.  Tin,  a  white.  Iron,  a 
carnation.  Ultra-marine,  blue.  Cobalt, 
blue.  Smalt,  light  blue.  Antimony,  yel- 
low and  red.  Manganese,  black.  Um- 
ber, for  browns.  The  flux  in  this  art  is 
like  the  oil  and  varnish  of  our  painting. 

The  best  flux  is  composed  of  16  flint- 
glass,  6  pearl-ash,  1  salt,  and  1  borax.  A 
soft  flux  is  8  flint-glass,  2  minium,  1  bo- 
rax. They  are  vitrified  together,  and  then 
powdered.  Pearl-ash  and  borax  soften, 
and  flint-glass  hardens. 

An  orange  stain  is  produced  by  silver 
and  antimony  for  yellow,  and  pure  Vene- 
tian, red.  The  two  first  are  melted  to- 
gether, and  when  reduced  to  impalpable 
?owder,  are  mixed  with  the  red  in  water, 
'his  pigment  is  then  laid  on  the  glass 
in  due  form,  with  a  brush,  and  left  to 
dry.  Then  burnt-in,  and  it  penetrates 
through  the  glass  in  a  fine  golden  color. 
So  with  other  metals,  and  other  colors, 
some  requiring  fluxes.  It  is  ably  treated 
at  length  by  Whittock,  and  being  an  art 
not  generally  practicable,  enough  has 
been  said  of  it  in  this  general  work. 

The  fluxes  are  used  in  calcining  black 
from  scales  of  iron,  jet,  and  inanganese ; 
carnation  from  red  chalk  and  jet ;  scarlet 
from  gold  and  tin,  &c,  &c. 

PALLADIUM.  A  rare  metal,  possess- 
ed of  valuable  properties,  was  discovered 
in  1803,  by  Dr.  Wollaston,  in  native  plat- 
inum. It  constitutes  about  1  per  cent,  of 
the  Columbian  ore,  and  from  $  to  1  per 
cent,  of  the  Uralian  ore  of  this  metal ; 
occurring  nearly  pure  in  loose  grains,  of" 
a  steel-gray  color,  passing  into  silver 
white,  and  of  a  specific  gravity  of  from 
11*8  to  12-14;  also  as  an  alloy  with  gold 
in  Brazil,  and  combined  with  selenium 
in  the  Harz  near  Tilkerode.  Into  the 
nitro-muriatic  solution  of  native  platin- 
um, if  a  solution  of  cvanide  of  mercury 
"be  poured,  the  pale  yeilow  cyanide  of  pal- 


ladium will  be  thrown  down,  which  be- 
ing ignited  affords  the  metal.  This  is 
the  ingenious  process  of  Dr.  Wollaston. 
The  palladium  present  in  the  Brazilian 
gold  ore  may  be  readily  separated  as  fol- 
ows  :  melt  the  ore  along  with  two  or  three 

Sarts  of  silver,  granulate  the  alloy,  and 
igest  it  with  heat  in  nitric  acid  of  speci- 
fic gravity  1-3.  The  solution  containing 
the  silver  and  palladium,  for  the  gold 
does  not  dissolve,  being  treated  with  com- 
mon salt  or  muriatic  acid,  will  part  with 
all  its  silver  in  the  form  of  a  chloride. 
The  supernatant  liquor  being  concentrat- 
ed and  neutralized  with  ammonia,  will 
yield  a  rose-colored  salt  in  long  silky  crys- 
tals, the  ammonia-muriate  of  palladium, 
which  being  washed  in  ice-cold  water, 
and  ignited,  will  afford  40  per  cent,  of 
metal. 

Pure  palladium  resembles  platinum, 
but  has  more  of  a  silver  hue ;  when  plan- 
ished by  the  hammer  into  a  cup,  such  as 
that  of  M.  Breant,  in  the  Museum  of  the 
Mint  at  Paris,  it  is  a  splendid  steel-white 
metal,  not  liable,  like  silver,  to  tarnish  in 
the  air.  Another  cup  made  by  M.  Breant, 
weighing  2  lbs.  (1  kilogramme),  was  pur- 
chased by  Charles  X.,  and  is  now  in  the 
garde-meuble  of  the  French  crown.  The 
specific  gravity  of  this  metal,  when  lam- 
inated, is  stated  by  Dr.  Wollaston  at  11-8, 
and  by  Vauquelin  at  12-1.  It  melts  at 
from  150°  to  160°  Wedgewood  :  and  does 
not  oxidize  at  a  white  heat.  When  a  drop 
of  tincture  of  iodine  is  let  fall  upon  the 
surface  of  this  metal,  and  dissipated  over 
a  lamp  flame,  a  black  spot  remains,  which 
does  not  happen  with  platinum.  A  slip 
of  palladium  nas  been  used  with  advan- 
tage to  inlay  the  limbs  of  astronomical  in- 
struments, where  the  fine  graduated  lines 
are  cut,  because  it  is  bright,  and  not  li- 
able to  alteration,  like  silver. 

There  are  a  protoxide  and  peroxide  of 
palladium.  The  proto-chloriae  consists 
of  60  of  metal  and  40  of  chlorine ;  the  cy- 
anide of  67  of  metal,  and  83  of  cyanogen. 

PALLETS,  in  clock  and  watch  work, 
are  the  pieces  connected  with  the  pendu- 
lum or  balance  which  receive  the  imme- 
diate impulse  of  the  swing-wheel,  or  bal- 
ance-wheel. They  are  of  various  forms 
and  constructions,  according  to  the  kind 
of  escapement  employed. 

PALMS.  Called  by  Linnseus,  from 
their  noble  and  stately  appearance,  the 
princes  of  the  vegetable  kingdom,  are  a 
natural  order  of  Arborescent  Endogens, 
chiefly  inhabiting  the  tropics,  distin- 
guished by  their  fleshy,  colorless,  six- 
parted  flowers,  inclosed  within  spathes ; 


424 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pap 


their  minute  embryo,  lying  in  the  midst 
of  albumen,  and  remote  from  the  hilum ; 
and  rigid,  plaited  or  pinnated  inarticulat- 
ed  leaves,  sometimes  called  fronds. 
Wine,  oil,  flax,  flour,  sugar,  and  salt,  says 
Humboldt,  are  the  produce  of  this  tribe ; 
to  which  Von  Martius  adds  thread,  uten- 
sils, weapons,  food,  and  habitations.  The 
most  common  species  is  the  cocoa-nut. 
Their  wounded  stems,  or  spathes,  yield 
in  abundance  a  saccharine  fluid,  known 
in  India  by  the  name  of  toddy.  The  suc- 
culent rind  of  the  date  is  a  most  nutritious 
as  well  as  agreeable  fruit.  Sago  is  yielded 
by  the  interior  of  the  trunks  of  nearly  all, 
except  Areca  catechu,  the  well  known  pi- 
sang,  or  betel-nut:  the  fruit  of  the  latter 
species  is  remarkable  for  its  narcotic  or 
intoxicating  power.  The  common  canes 
or  rattans  of  the  shops  are  the  flexible 
stems  of  species  of  the  genus  Calamus. 

PALM  OIL  is  obtained,  in  Guinea  and 
Guyana,  by  expressing,  as  also  by  boiling, 
the  fruit  of  the  avoira  elais.  It  has  an 
orange  color,  a  smell  of  violets,  a  bland 
taste,  is  lighter  than  water,  melts  at  84° 
Fahr.,  becomes  rancid  and  pale  by  ex- 
posure to  air,  dissolves  in  boiling  alcohol, 
and  consists  of  69  parts  of  oleine,  and  31 
of  stearine,  in  100.  It  is  employed  chiefly 
for  making  yellow  soap.  It  may  be 
bleached  by  the  action  of  either  chlorine 
or  oxygen  gas,  as  also  by  that  of  light  and 
heat. 

Besides  the  foregoing  source,  much  of 
the  palm  oil  of  commerce  is  obtained  from 
the  Cocos  butyracm,  and  is  a  concrete, 
white,  unctuous,  substance,  rendered 
fluid  and  fragrant  by  gentle  heat.  As  a 
substitute  for  tallow,  it  is  the  greatest  do- 
mestic improvement  of  late  years,  and  it 
is  so  abundant,  both  in  Africa  and  Brazil, 
that  it  will,  ere  long,  by  cultivation,  super- 
sede tallow  for  candles  and  soap,  and 
even  coals,  for  gas-making. 

The  palm-tree,  growing  on  the  coast  of 
Africa,  furnishes,  at  the  base  or  origin  of 
its  leaves,  clusters  of  a  yellow  succulent 
fruit.  Each  of  these  bears  some  resem- 
blance to  a  grape-shot.  The  bunches  are 
of  different  sizes,  and  the  fruit  composing 
them  of  different  shapes,  as  might  be  ex- 
pected from  their  reciprocal  pressure,  al- 
though naturally  round,  when  not  expos- 
ed to  it.  The  pulp  of  this  fruit  is  soft, 
and  of  a  bright  yellow  color — it  is  from 
this  that  the.  oil  is  obtained.  Within  it 
lies  inclosed  a  hard  and  thick-shelled 
stone,  of  a  dark  color,  within  which  is 
contained  a  firm  white  kernel,  of  a  pleas- 
ant oily  flavor.  This  kernel  also  affords 
an  oil,  which  is  not  yellow,  but  white — 


and  not  fluid,  but  concrete  even  in  Af 
frica. 

The  yellow  palm-oil,  is  quite  fluid  whilo 
in  Africa,  and  that  it  is  not  until  it  has 
been  exposed  to  the  cold  of  our  temper- 
ate regions  that  it  becomes  solid — where- 
as the  oil  of  the  kernel  is  always  concrete, 
or  nearly  so.  Both  the  white  and  the 
yellow  oil  are  obtained  by  expression. 
The  latter  is  procured  in  immense  quan- 
tities in  Africa,  where  it  is  partly  consum- 
ed by  the  negroes  along  with  their  rice 
and  pepper,  or  fried  with  their  fish  ;  and 
partly  exported  to  Europe,  where  its 
principal  use  is  in  the  manufacture  oi 
soap  and  candles. 

PAPER.  A  thin  and  flexible  sub- 
stance of  various  colors,  but  most  com- 
monly white,  used  for  writing  and  print- 
ing on,  and  for  various  other  purposes. 
It  is  manufactured  of  vegetable  matter, 
reduced  to  a  pulp  by  means  of  water  and 
grinding;  and  is  made  up  into  sheets, 
quires,  and  reams,  each  quire  consisting 
of  twenty-four  sheets,  and  each  ream  ol 
twenty  quires. 

For  the  chief  purposes  to  which  paper 
is  applied  in  modern  times  the  ancients 
had  recourse  to  a  variety  of  materials : 
stone,  tablets  of  wood,  plates  of  lead, 
skins,  parchment,  linen,  layers  of  wax, 
tablets  of  ivory,  and,  above  all,  the  papy- 
rus. The  ability  to  write,  created  a  ne- 
cessity for  some  material  on  which  to  in- 
cribe ;  and  all  these  various  materials 
were  resorted  to  in  succession,  as  the  in- 
eligibility of  each  induced  a  fresh  endea- 
vor to  discover  some  more  desirable 
substitute. 

The  papyrus  was  the  immediate  pre 
cursor  of  paper,  and  the  article  from 
which  it  was  first  manufactured.  Egypt 
has  the  honor  of  the  invention  ;  and  Isi- 
dore even  fixes  the  locality  at  Memphis  ; 
the  date  remains  in  some  obscurity,  al- 
though it  has  been  warmly  disputed. 
Varro  the  Koman,  ascribes  it  to  the  time 
of  Alexander  the  Great,  after  the  found- 
ing of  Alexandria ;  but  we  find  in  Pliny 
the  recital  of  a  passage,  extracted  from 
the  writings  of  Cassius  Hemina,  an  an- 
cient annalist,  in  which  he  speaks  of 
some  books,  found  in  the  tomb  of  Numa 
when  it  was  opened,  535  years  after  his 
decease,  and  asserts  that  these  books 
were  of  paper,  and  had  been  interred 
with  him.  As  Numo  preceded  Alexan- 
der 300  years,  this  circumstance,  if  ad- 
mitted, would  carry  back  the  date  of  the 
invention  anterior  to  that  time.  How- 
ever, the  antiquity  of  such  a  date  is  much 
doubted ;   but  as  Pliny  gives  an  account 


pap] 


CYCLOPEDIA    OF   THE   USEFUL    ARTS. 


425 


of  the  manner  of  making  the  papyrus 
paper,  and  it  seems  to  have  been  in  high 
reputation  in  the  time  of  Alexander  the 
Great,  it  is  probable  that  such  improve- 
ments were  made  during  his  reign  as  to 
enhance  the  value  and  increase  the  man- 
ufacture. 

The  great  improvement  in  paper  was 
its  manufacture  from  cotton.  It  is  sup- 
posed that  the  Chinese  and  Persians 
were  acquainted  with  this  material  for 
its  production,  and  that  the  Arabians 
learned  it  from  their  conquest  inTartary. 
The  ancient  paper  bears  no  marks  of  the 
wire  through  which  the  water  is  drained 
in  modern  paper-making ;  and  it  is 
therefore  inferred  that  a  different  process 
was  employed.  Paper  made  from  cotton 
was  in  use  earlier  with  the  Greeks  than 
with  the  Eomans.  The  manufacture  of 
paper  from  cotton  cannot  be  traced 
farther  back  than  to  the  tenth  century ; 
and  the  oldest  mauuscript  document 
written  on  this  cotton  paper  is  dated 
1050. 

When  or  by  whom  linen  paper  was  in- 
vented seems  uncertain :  the  Chinese 
appear  to  have  the  best  pretensions.  Its 
introduction  into  England  took  place 
about  the  year  1342,  in  the  reign  oi  Ed- 
ward III.,  although  some  have  supposed 
it  as  early  as  1320.  France  had  it  in 
1314,  and  Italy  in  1367.  The  Germans 
possess  a  specimen  bearing  the  date  of 
1308,  although  it  has  been  surmised  that 
this  single  instance  may  have  been  a 
mixture  of  linen  with  cotton. 

In  the  Tower,  there  are  a  few  letters 
upon  cotton  paper,  yet  parchment  or 
vellum  was  generally  used ;  and  these 
are  among  the  earliest  examples  of  any 
continued  correspondence  upon  the  more 
commodious  material,  which  in  England 
was  very  rarely  employed.  It  is  highly 
probable  that,  in  the  south  of  France, 
the  supply  was  received  from  the  Moor- 
ish merchants  or  manufacturers  of  Spain. 

Perhaps  no  other  manufacture  ever  re- 
mained so  long  nearly  stationary ;  though 
within  the  last  fifty  years  such  great  and 
rapid  improvements  have  been  made  in 
it,  as  to  equal,  if  not  to  surpass,  any 
other  branch  of  manufacturing  industry. 

The  application  of  paper  to  the  pur- 
poses of  writing  and  printing,  and  the 
fact  of  its  being  indispensable  to  the  pro- 
secution of  the  latter,  render  its  manu- 
facture of  the  highest  utility  and  impor- 
tance. But,  even  in  a  commercial  point 
of  view,  its  value  is  very  considerable. 
France,  Holland,  and  Genoa  had,  for  a 
lengthened  period,  a  decided  superiority 


in  this  department.  The  finest  and  beat 
paper  being  made  of  linen  rags,  its  qua- 
lity may  be  supposed  to  depend,  in  a 
considerable  degree,  on  the  sort  of  linen 
usually  worn  in  the  country  where  it  is 
manufactured ;  and  this  circumstance  is 
said  to  account  for  the  greater  whiteness 
of  the  Dutch  and  Belgian  papers  as  com- 
pared with  those  of  the  French  and  Ita- 
lians, and,  still  more,  of  the  Germans. 
The  rags  used  in  the  manufacture  of 
writing-paper  in  Great  Britain,  are  col- 
lected at  home;  but  those  used  in  the 
manufacture  of  the  best  printing-paper 
are  imported  principally  from  Italy,  Ham- 
burgh, and  the  Austrian  States,  by  way 
of  Trieste.  The  value  of  the  rags  saved 
in  the  United  States  is  nearly  2i  million 
dollars  yearly. 

We  believe,  however,  that  it  was 
owing  rather  to  the  want  of  skill,  than, 
as  has  sometimes  been  supposed,  to  the 
inferior  quality  of  the  linen,  that  the 
manufacture  of  paper  was  not  carried  on 
with  much  success  in  England  till  a  com- 
paratively recent  period.  The  manufac- 
ture is-  said  to  have  been  considerably 
improved  by  the  French  refugees  who 
fled  to  England  in  1685.  In  1690,  how- 
ever, the  manufacture  of  white  paper 
was  attempted  ;  and,  within  a  few  years, 
most  branches  were  much  improved.  In 
1721,  it  is  supposed  that  there  were 
about  300,000  reams  of  paper  annually 
produced  in  Great  Britain,  which  was 
equal  to  about  two-thirds  of  the  whole 
consumption.  In  1783,  the  value  of  the 
paper  annually  manufactured  was  esti- 
mated at  £780,000.  At  present,  besides 
making  a  sufficient  quantity  of  most 
sorts  of  paper  for  our  own  use,  we  an- 
nually export  about  £100,000  worth  of 
books. 

In  1813,  Dr.  Colquhoun  estimated  the 
value  of  paper  annually  produced  in 
Great  Britain  at  £2,000,000;  but  Mr. 
Stevenson,  an  incomparably  better  autho- 
rity upon  such  subjects,  estimated  it  at 
only  half  this  sum.  From  information 
obtained  from  those  engaged  in  the 
trade,  we  incline  to  think  that  the  total 
annual  value  of  the  paper  manufacture 
in  the  United  Kingdom,  exclusive  of  the 
duty,  may  at  present  amount  to  about 
£1,200,000  or  £1,300,000.  There  are 
about  700  paper-mills  in  England,  and 
from  70  to  80  in  Scotland.  The  number 
in  Ireland  is  but  inconsiderable.  About 
27,000  individuals  are  supposed  to  be  di- 
rectly engaged  in  the  trade ;  and,  besides 
the  workmen  employed  in  ftw  mi'te,  the 
paper  manufacture  creates  a  considerable 


426 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[pap 


demand  for  the  labor  of  millwrights,  ma- 
chinists, smiths,  carpenters,  iron  and 
brass-founders,  wire-workers,  woollen 
manufacturers,  and  others  in  the  ma- 
chinery and  apparatus  of  the  mills. 
Some  parts  of  these  are  very  powerful, 
and  subject  to  severe  strain;  and  other 
parts  are  complicated  and  delicate,  and 
require  continual  renovation. 

Most  of  the  American  printing-paper  is 
of  cotton,  on  account  of  the  extensive 
use  of  that  article  ;  and  hence  it  is  soft, 
easily  torn,  and  perishable.  The  paper 
manufacture  has  rapidly  increased  in  this 
country.  In  1829,  the  quantity  made  in 
this  country  amounted  to  from  five  to 
seven  millions  a-year,  and  employed 
ten  to  eleven  thousand  persons.  Ma- 
chinery is  almost  altogether  employed, 
and  the  quality  of  the  paper  is  improved 
It  becomes  better  by  keeping,  and  is 
therefore  difficult  to  obtain  in  this  coun- 
try, the  interest  of  capital  being  too  high. 
Much  of  the  linen  paper  now  made  is 
from  rags  imported,  of  which  there  were, 
at  the  port  of  New  York  alone,  during 
1846, 1847,  and  1848,  the  following  quan- 
tities imported : — 

1846,  Bales, 7,066 

1847,  „      15,463 

1848,  „ 23,313 

The  exports  of  paper  and  stationery  in 
the  years  1847  and  1848  were,  respec- 
tively, of  the  value  of  $88,731  and 
$78,307. 

We  pass  on  from  this  brief  account  of 
the  history  and  statistics  of  paper  to  the 
mechanical  process  of  its  production ; 
only  remarking,  that  many  articles  have 
been  resorted  to  in  its  manufacture — the 
tendrils  of  the  vine,  the  stalks  of  the 
nettle,  the  thistle,  and  mallow ;  the  bark 
of  the  willow,  the  hawthorn,  the  beech, 
the  aspen,  and  the  lime.  Some  patents 
have  been  obtained  for  making  it  of 
straw;  and  the  bine  of  the  hop,  it  is  pre- 
sumed, might  furnish  material  for  the 
supply  of  paper  ;  but,  leaving  these  in- 
ferior substitutes,  we  shall  confine  our- 
selves to  the  description  of  paper  made 
from  linen  rasrs,  that  being  the  staple  of 
the  manufacture. 

The  rags  are  sold  to  the  manufacturers 
according  to  their  respective  quality: 
fine,  being  wholly  linen,  and  of  the  best 
quality,  is  used  for  the  finest  writing- 
paper,  and  so  in  their  gradation  down  to 
the  commonest,  which  is  coarse,  often 
canvass,  and  can  only  be  made  into  an 
inferior  printing-paper  when  it  has  been 
thoroughly  bleached.      In  these  inferior 


papers  some  cotton  is  mixed.  There  are 
also  the  strong,  coarse  bags  in  which  the 
rags  are  packed,  and  the  colored  rags, 
only  fit  for  the  most  common  papers; 
though  out  of  these  the  blue  are  usually 
sorted  for  the  purpose  of  making  blue 
paper.  It  is  necessary  that  these  rags 
should  be  dusted ;  and,  to  accomplish 
this,  they  are  either  placed  in  a  cylinder, 
formed  of  wire  net,  turning  on  pivots  at 
each  end,  and  enclosed  in  a  box  which 
receives  the  dust  as  it  falls  through  the 
net-work,  or  else  their  sorting  takes  place 
over  a  table  frame  covered  with  wire  net, 
through  which  the  dust  falls  into  a  box 
beneath,  as  the  workwoman  proceeds  in 
her  labours.  The  first  of  these  modes, 
however,  is  a  great  preservation  of  the 
health  of  those  employed  in  the  work. 
The  rags  are  then  cut  into  pieces  not  ex- 
ceeding three  or  four  inches  square,  the 
parts  that  have  seams  being  thrown  into 
a  separate  heap,  or  the  sewing-thread 
might  make  filaments  in  the  paper.  In 
this  process  the  rags  are  scrupulously 
sorted  according  to  their  texture  and  de- 
gree of  strength,  not  according  to  their 
color;  for,  were  they  not  carefully  ar- 
ranged by  this  rule,  the  fine  in  texture 
would  be  reduced  to  a  pulp  long  before 
the  coarse,  and  be  lost  in  the  prepara- 
tion ;  or,  if  preserved,  when  reduced  to 
a  pulp,  would  not  be  found  of  the  same 
consistency  as  the  coarser  sorts,  and  the 
paper,  when  manufactured,  would  neces- 
sarily be  clouded  and  inferior.  It  is  for 
these  reasons  that  this  part  of  the  pro- 
cess is  important.  When  carefully  sort- 
ed, and  the  different  degrees  of  texture 
having,  by  a  longer  or  shorter  process, 
been  reduced  to  a  pulp  of  similar  con- 
sistency, they  may  then  be  mixed  to- 
gether ;  but  this  cannot  be  previously 
done.  While  in  this  state  the  rags  often 
appear  so  dirty  and  discolored  as  to  pre- 
clude all  hope,  to  an  inexperienced  eye, 
that  they  can  ever  assume  the  purity  of 
that  beautiful  fabric  so  valuable  co  the 
artist  and  the  scribe.  This  purification 
used  formerly  to  be  effected  by  water 
running  through  a  receptacle  filled  with 
the  rags,  which  in  its  passage  eventually 
carried  off  their  soil ;  but  the  present 
more  expeditious  process  is  that  of  boil- 
ing them,  mixed  up  with  lime,  in  a  spe- 
cies of  chest,  so  perforated  as  to  allow  the 
admission  of  steam  ;  and  by  this  means 
they  are  partially  bleached.  Bleaching 
takes  an  important  place  in  the  process. 
The  superfluous  moisture  is  squeezed 
from  the  rags,  and  they  arc  placed  in  a 
sort  of  chamber  or  receiver,  which  is  air* 


PAPJ 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


427 


tight,  and  pipes  are  conducted  into  it 
from  a  retort,  which  convey  chlorine, 
formed,  hy  the  application  of  heat,  from 
manganese,  common  salt,  and  sulphuric 
acid.  This  part  requires  much  care  ;  for 
if  carried  beyond  its  due  point,  it  proves 
most  injurious  to  the  durability  of  the 
fabric.  The  rags  when  taken  from  this 
chamber  are  strongly  imbued  with  a 
most  nauseous  smell,  and  require  pro- 
fuse and  frequent  washings.  After  this 
process  they  are  put  into  the  beating  en- 
gines, and  pass  through  a  sort  of  tritura- 
tion, which  reduces  them  to  a  coarse  and 
imperfect  pulp,  which  is  called  half  stuff 
or  first  stuff,  and  this  is  again  levigated 
until  it  assumes  the  appearance  of  cream. 

The  state  and  quality  of  this  pulp  is  of 
the  utmost  importance  to  the  final  per- 
fection of  the  paper.  If,  in  the  leviga- 
tion,  the  fibre  should  have  been  so  en- 
tirely destroyed  as  to  reduce  it  to  a  jelly, 
the  paper  will  inevitably  prove  liable  to 
break,  moulder  away,  and  be  rotten; 
and  this  must  result  whatever  be  the  pre- 
vious excellence  of  the  material.  A  fibre 
is  absolutely  necessary  to  the  production 
of  a  servicable  paper.  Mr.  Murray,  in  a 
little  work  on  the  subject  full  of  practical 
science,  recommends  that  a  small  propor- 
tion of  unbleached  flax  should  be  added 
to  the  half  stuff — an  expedient  that  would 
doubtless  much  increase  the  strength 
and  durability  of  the  manufacture.  But, 
unfortunately,  so  far  from  means  being 
taken  to  improve  its  consistency,  others 
are  resorted  to,  for  the  sake  of  an  in- 
creased profit,  which  deteriorate  almost 
to  destruction :  we  mean  the  introduc- 
tion of  plaster  of  Paris,  or  other  earthy 
substances,  into  the  pulp ;  and  this  can 
never  be  done  without  ensuring  brittle- 
ness  and  want  of  cohesion  as  the  result. 
While  the  pulp  is  in  this  state,  the  size, 
made  from  sheep-skins  and  other  animal 
substances,  together  with  a  solution  of 
alum,  is  introduced,  excepting  only  in 
the  manufacture  of  writing  paper,  and 
then  the  sheets  are  most  generally  sized 
after  their  formation. 

A  patent  was  granted  in  1847,  in  this 
country,  for  the  mode  of  making  the 
pulp  from  straw.  The  material  of  straw 
has  long  been  used  for  this  purpose,  but 
the  method  of  treatment  is  believed  to  be 
new,  and  is  as  follows  : — The  straw,  or 
other  vegetable  fibrous  material,  is  heat- 
ed or  boiled  with  milk  of  lime  twelve 
hours,  in  a  suitable  boiler,  and  the  lime 
and  coloring  matter  washed  out  in  a  suit- 
able tub.  The  fibrous  matter  is  then 
transferred  to  mill-stones,  so  arranged  as 


to  crush  it,  and  at  the  end  of  this  opera 
tion  the  pulpy  matter  is  again  transferred 
to  another  tub  for  further  washing  out 
the  coloring  matter.  The  pulpy  matter 
is  next  removed  to  a  second  set  of  boil- 
ers, where  fresh  lime-water  and  an  alka- 
line solution  of  the  strength  of  two  to 
four  degrees  of  the  hydrometer  is  sup- 
plied, and  the  heat  continued  for  six 
hours. 

At  the  end  of  this  time,  the  whole  li- 
quor and  pulp  are  forced  up  by  steam 
pressure  into  a  third  washing  tub,  where 
it  is  washed,  and  sulphuric  or  muriatic 
acid  of  the  ordinary  strength  used  for 
bleaching  purposes,  is  supplied,  and  the 
contents  kept  in  agitation  for  two  hours, 
and  the  acid  is  then  entirely  washed  out. 
The  pulp  is  next  returned  to  the  second 
set  of  boilers,  where  it  is  mixed  with 
alkali  of  the  strength  of  two  to  four  de- 
grees of  the  hydrometer,  and  boiled  four 
hours,  or  until  the  alkali  is  spent. 

The  pulp  and  liquor  are  again  forced 
up  into  the  third  washing  tub,  and  all 
soluble  matters  washed  out  of  it.  Chlo- 
ride of  lime  of  the  ordinary  bleaching 
strength  is  now  added,  and  agitation 
kept  up  for  two  hours  longer;  when 
steam  is  let  on  and  the  boiling  continued 
until  the  salt  is  spent,  when  the  whole  is 
discharged  into  the  fourth  tub,  where 
the  spent  chloride  of  lime  is  washed  out. 
The  pulp  is  now  subjected  to  the  opera- 
tion of  souring,  which  consists  of  sub- 
mitting it  to  the  action  of  acid  and  water 
of  the  usual  strength  used  for  bleaching, 
and  keeping  the  whole  in  agitation  for 
four  hours.  It  is  now  ready  to  be  dis- 
charged into  a  fifth  tub  or  set  of  tubs, 
when  the  process  is  considered  as  com- 
pleted. 

The  fine  pulp,  or  stuff,  as  it  is  techni- 
cally called,  is  transferred  into  a  chest  or 
large  tub  with  a  revolving  agitator;  from 
thence  into  a  vat,  usually  about  5  feet  in 
diameter,  and  2i  feet  in  depth,  and  sus- 
tained at  a  proper  temperature  by  means 
of  a  fire  ;  and  it  is  generally  arranged  for 
this  vat  to  be  placed  against  a  wall  of  the 
room,  that  the  fuel  to  the  fire  may  be 
supplied  at  an  aperture  externally,  to 
prevent  any  injury  from  smoke.  During 
the  whole  of  the  subsequent  process  it  is 
requisite  that  the  pulp  in  the  vat  should 
be  stirred  up  at  short  intervals,  to  keep 
it  of  an  equal  consistency.  There  are 
three  workmen  employed  in  this  stage  of 
the  operation,  called  the  dipper,  the 
covcher,  and  the  lifter.  The  dipper  is 
provided  with  a  mould,  formed  of  well- 
seasoned  mahogany,  across  which  par- 


428 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[pap 


allel  wires  are  stretched  close  together,  a 
few  other  stronger  ones  being  also  placed 
at  right  angles  with  them,  and  at  some 
distance  from  each  other.  The  lines 
formed  in  the  paper  by  these  wires  are 
called  water-mark& ;  but,  in  the  modern 
improvement  of  wove  paper,  these  are 
avoided  by  using  wire  cloth  woven  in  a 
loom,  which,  being  tightly  stretched  over 
the  frame,  produces  no  water-mark. 
This  mould  is  provided  with  another 
frame,  called  a  deckle,  which  fits  it  exact- 
ly, and  forms  a  boundary  line  to  the  sheet 
of  paper,  which  would  otherwise  have  a 
rough  and  jagged  edge.  This  contri- 
vance, by  supplying  an  edge  to  the 
mould,  gives  it  the  character  of  a  sieve, 
which  enables  the  dipper,  after  he  has 
dipped  the  mould  into  the  vat,  and  taken 
in  a  sufficient  quantity  of  the  pulp,  and 
given  it  a  gentle  motion  to  equalize  its 
thickness,  to  drain  the  water  away ;  he 
then  removes  the  deckle,  replaces  it  on 
another  mould,  and  proceeds  as  before ; 
while  the  second  workman,  the  coucher, 
removes  the  sheet  of  paper  thus  made 
on  to  a  felt,  being  a  piece  of  woollen 
cloth,  and  then  returns  the  mould  to  the 
dipper,  who,  in  the  meantime,  has  been 
operating  with  another  mould,  and  form- 
ing another  sheet :  they  thus  exchange 
the  moulds,  the  one  dipping,  and  the 
other  couching,  until  they  have  com- 
pleted six  quires  of  paper,  which  is  called 
a  post.  When  this  quantity  is  com- 
pleted, the  heap  is  conveyed  to  the  vat 
press,  and  subjected  to  heavy  pressure. 
These  six  quires  remain  in  the  vat  press 
until  the  dipper  and  the  coucher  have 
perfected  another  post,  when  they  are 
removed  to  give  place  to  it  •  and  then 
the  office  of  the  third  workman,  the 
lifter,  commences.  He  separates  the 
sheets  of  paper  from  the  felts,  and  forms 
them  into  a  pile,  which  is  again  subjected 
to  a  second  press,  which  detaches  from 
them  a  great  quantity  of  moisture.  Here 
it  remains  until  the  workmen  are  pre- 
pared to  replace  it  with  a  similar  quan- 
tity, when  it  is  taken  to  the  drying 
rooms,  and  hung  up  on  lines  to  dry. 
These  lines  are  carefully  covered  with 
wax,  both  to  prevent  adhesion  and  con- 
traction ;  and  the  opening  of  the  win- 
dows should  be  strictly  attended  to,  that 
the  drying  may  not  proceed  too  rapidly. 
This  being  accomplished,  it  is  taken 
down,  shaken,  to  make  the  dust  fall  out, 
and  to  separate  the  sheets  from  each 
other,  and  laid  up  in  heaps  ready  to  be 
sized.  The  size  is  prepared  of  a  due 
consistence,  twice  filtered,  and  a  portion 


of  alum  added.  The  workman  dips  a 
handful  of  the  sheets,  holding  them  open 
at  the  edges,  that  they  may  more  equally 
imbibe  the  moisture,  and  after  this  pro- 
cess they  are  again  subjected  to  the 
press.  They  are  afterwards  dried,  sorted, 
Drought  under  repeated  and  excessive 
pressure,  and,  finally,  made  up  into 
quires  and  reams. 

But  as  the  process  of  paper-making 
must  necessarily  be  comparatively  slow 
when  practised  by  hand,  machinery  has 
been  resorted  to,  which  ha3  nearly  sup- 
planted the  old  method.  We  believe 
France  has  the  honor  of  the  invention, 
although  it  has  been  greatly  improved  in 
England  by  Messrs.  Donkin  and  Co. 
That  in  most  general  use  there  is  after 
Fourdrinier,  who  invented  the  endless 
web  of  wire.  One  of  these  machines 
can  produce  25  superficial  feet  of  paper 
per  minute ;  and  it  is  this  which  enables 
England  to  enter  into  competition  with  the 
foreign  market,  which  it  could  not  other- 
wise do,  on  account  of  the  difference  in  the 
value  of  manual  labor.  In  the  old  me- 
thod, it  took  three  months  after  receive 
ing  the  rags  into  the  mill  to  complete  the 
paper :  by  the  machine,  they  can  receive 
the  rags  on  one  day,  and  deliver  the 
paper  made  from  them  on  the  next. 

The  stuff,  having  been  prepared  and 
bleached  in  an  expeditious  manner  by 
machinery,  is  emptied  into  the  chest,  or 
tub,  as  before,  and  from  thence  is  de- 
livered gradually  into  the  vat,  where  it  is 
kept  in  continual  motion  by  means  of 
revolving  fans,  called  hogs.  Nearly  at 
the  top  of  the  vat  there  is  a  gate,  which 
can  be  raised  or  lowered  at  pleasure,  by 
means  of  which  the  flow  of  stuff  is  regu- 
lated on  to  the  lip  or  trough,  from  which 
it  falls  upon  the  endless  web  of  fine  wire, 
which  is  kept  continually  moving  in  a 
horizontal  direction  over  a  series  of  re- 
volving rollers,  and  is  placed  imme- 
diately under  the  hanging  lip  of  the 
trough,  so  that  the  pulp  may  nave  the 
shortest  distance  possible  to  fall.  These 
revolving  rollers  prevent  the  wire  web 
from  falling  in  or  bagging,  and  keep  it 
level ;  and  as  it  is  preserved  at  a  due 
tenison  from  side  to  side,  it  has  all  the 
appearance  of  a  table.  A  leather  strap, 
or  ledge  of  wood,  on  each  side,  forms 
the  boundary  line  of  the  paper,  answer- 
ing the  purpose  of  the  deckle  in  the 
hand-making  process;  these  are  mov- 
able, according  to  the  intended  width  of 
the  paper.  The  long  cascade  or  con- 
tinuous stream  of  pulp,  regulated  with 
reference  to  the  proposed  thickness  of 


I'AP] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


429 


the  paper  to  be  made,  thus  gently  de- 
scends on  this  moving  wire  plane,  which 
is  perpetually  travelling  onward  and  on- 
ward ;  and,  for  its  more  perfect  equaliza- 
tion, a  second  movement  is  resorted  to, 
by  means  of  a  sort  of  crank,  which  gives 
the  web  a  jerking  motion  at  short  inter- 
vals, and  diffuses  the  liquid  pulp  un- 
varyingly over  the  surface.  At  the  end 
nearest  to  the  trough  the  pulp  is,  of 
course,  perfectly  fluid ;  but,  as  the  web 
travels  on,  the  moisture  partially  sinks 
through  the  fine  apertures  of  the  webbing, 
and  the  material  coagulates.  There  has 
been  a  fashion  prevalent  of  late  yeai's  of 
having  paper  barred  or  ribbed :  this  ap- 
pearance is  given  at  this  juncture.  While 
yet  moist,  just  before  passing  from  the 
wire  webbing,  it  is  subjected  to  the  pres- 
sure of  a  wire  roller,  which  gives  the  in- 
dentations of  the  stripes  or  lines ;  this 
cylinder  is  called  a  dandy ;  from  this  it 
travels  to  a  web  of  cloth  or  felt,  during 
which  advance  it  is  subjected  to  heavy 
pressures,  from  passing  between  rollers 
covered  with  felt,  and  called  the  pressing 
rollers.  This  process  answers  to  the  wet 
press  in  the  hand-made  paper ;  and  for- 
merly this  was  the  termination  of  the  la- 
bors of  the  machines,  the  remaining 
work  of  drying,  &c,  being  accomplished 
by  hand.  But  an  incalculable  improve- 
ment took  place  in  the  addition  of  the 
drying  rollers.  These  are  three  cylinders 
of  polished  metal,  which  effect  in  a  few 
moments  the  perfect  drying  of  the  paper : 
while  yet  moist  it  passes  over  the  first 
moderately  warm  ;  again  over  the  second, 
of  larger  diameter,  of  greater  warmth  ; 
and  again  over  the  third,  with  an  aug- 
mented heat  The  paper  is  now  perfectly 
dry,  and  any  casual  inequalities  are  re- 
moved from  its  surface.  The  final  action 
of  this  wonderful  machine  is  to  wind  the 
paper  round  a  last  roller  or  reel,  which 
when  full,  is  exchanged  for  another,  and 
so  on  successively. 

Here  the  work  of  the  machine  is  finish- 
ed ;  and  the  paper,  being  in  long  webs  of 
many  yards,  requires  to  be  cut  into 
sheets.  After  different  methods  had 
been  tried,  a  supplementary  machine  has 
been  invented,  which  receives  the  web 
from  off  the  reel  on  to  a  drum,  cuts  it 
into  sheets  of  proper  length  with  a  circu- 
lar knife,  continually  revolving,  while 
the  divided  web  proceeds ;  and  these 
sheets  are  received  and  placed  in  regular 
heaps  by  children. 

In  this  country,  machining  is  more 
used  than  in  Europe.  In  the  year  1848, 
eight  patents  were  granted  for  improve- 


I  ments  in  machines  used  in  manufactur- 
j  ing,  cutting,  and  performing  other  opera- 
tions on  paper. 

One  of  these  patents  is  for  improved 
machinery  for  grinding  the  pulp.  The 
machine  much  resembles  mills  for  grind- 
ing grain.  It  is  so  arranged  that  the 
pulp  is  kept  in  circulation  through  the 
mill,  passing  in  at  the  eye  and  out  at  the 
edges,  until  the  whole  is  properly  pre- 
pared. 

In  one  of  the  machines  patented,  the 
paper  is  cut  into  sheets  of  any  desired 
length,  placed  upon  a  table,  and  the 
edges  adjusted  for  folding.  To  insure 
corresponding  action  throughout,  the 
motions  of  various  parts  of  the  machine 
are  takon  from  the  cylinder  which  car- 
ries the  knife. 

Others  of  these  machines  cut  the  pa- 

Eer  and  drop  it  upon  rods,  over  which  it 
ends  and  hangs  preparatory  to  folding. 
The  manufacture  of  the  paper  being 
thus  completed,  the  sheets  are  separately 
examined,  and  every  knot  or  blemish 
carefully  removed,  the  torn  or  damaged 
ones  being  laid  apart.  In  this  state  they 
are  subjected  to  the  action  of  a  powerful 
press,  in  the  full  and  open  size  of  the 
sheet :  they  are  afterwards  cut  round  the 
edge,  and  then  counted  into  quires  of 
twenty-four  sheets,  which  are  folded  in 
the  middle,  and  put  into  reams,  each 
ream  containing  twenty  quires,  of  which 
the  two  on  the  outside  are  made  up  of* 
twenty  sheets  each,  from  the  damaged 
sheets  that  were  thrown  out.  In  this 
state  they  are  again  pressed,  and  finally 
tied  up  in  wrappers. 

India  paper. — The  material  employed 
by  the  Chinese  is  the  liber,  or  interior 
bark  of  a  sort  of  mulberry,  commonly 
called  the  paper-tree,  and  known  to 
botanists  under  the  name  of  broussonetia 
papyrifera.  Kempfer  has  described  the 
process  pursued  in  China  in  the  manu- 
facture of  this  paper.  Dr.  Postans  re- 
cently has  described  the  material  as  the 
coarse  hempen  bagging  used  by  the 
bringarries,  when  torn  to  rags  in  their 
service.  These  are  cut,  and  well  washed 
in  tanks,  near  Kivzapone,  in  the  Deccan. 
They  are  then  bleached  and  dried:  in 
twelve  days  they  are  converted  into  a 
pulp,  which  is  then  made  into  4  lb.  balls, 
about  as  big  as  a  man's  head.  These  are 
afterwards  wet  with  water,  and  made 
into  paper  on  a  frame  made  of  fine  reeds, 
A  man  and  a  boy  make  the  sheet,  and  a 
third  man  removes  them,  who  first 
presses  them  under  large  stones  to  dry 
them,  and  then  plasters  them  against  the 


430 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[pap 


walls  of  the  room  to  dry  them.    It  is  then  | 
coated  with  gum  size,  and  polished  with 
stones. 

Bice  paper. — The  substance  called  in 
England,  "rice  paper,"  is  made  of  the 
branch  of  the  rice  plant  in  China. 

Mr.  Gill  remarks,  that  the  Chinese 
u  rice  paper"  is  an  organized  vegetable 
production,  much  resembling,  in  its 
structure,  the  pith  of  elder.  He  thinks 
cylindrical  pieces  of  elder  or  other  pith 
might  be  found  in  any  country,  quite 
large  enougn  to  bear  slicing  in  this  man- 
ner ;  and  which  slices,  after  being  flatten- 
ed by  pressure  between  plates  (possibly 
warmed  or  heated)  might  serve  as  sub- 
stitutes ;  and  be  as  capable  of  receiving 
any  colors. 

Paper  from  the  husks  of  Indian  corn. — 
To  128  gallons  of  water  put  10  quarts  of 
good  lime,  or  about  6  lbs.  of  good  alkali, 
and  place  therein  about  110  lbs.  of  clean 
corn-husks  or  flag-leaves.  Let  the  water 
be  moderately  heated  over  a  gentle  fire, 
for  two  hours,  when  they  will  be  ready 
for  the  engine,  there  to  be  worked,  and 
managed,  in  every  respect,  as  rags  are 
for  making  paper. 

Straw  paper. — Take  any  quantity  of 
straw,  hay,  or  other  vegetable  sub- 
stances, and  boil  it  in  a  solution  or  ley  of 
pot  or  pearl-ash,  or  other  alkali  or  lime, 
in  the  following  proportions,  viz.,  to 
115  lbs.  of  straw,  hay,  or  other  vegetable 
substance,  add  from  15  lbs.  to  20  lbs.  of 
the  salts  or  ley  of  pot  or  pearl  ash,  or 
other  alkali  of  iime,  and  boil  them  about 
80  minutes,  or  steep  the  materials  in  the 
solution  a  few  day*,  or  until  saturated, 
then  draw  off  the  water,  and  put  them 
into  a  common  engine,  to  be  manufac- 
tured into  paper,  like  rags. 

Paper  from  wood. — Any  wood  may  be 
reduced  to  shavings,  which  are  thrown 
into  a  caldron  of  water,  and  set  to  boil. 
To  every  100  lbs.  of  shavings,  from  12  lbs. 
to  18  lbs.  of  any  vegetable  or  mineral 
alkali  (according  to  its  strength)  are  to  be 
added.  100  lbs.  of  wood  will  make  from 
five  to  seven  reams  of  paper. 

Paper  linen  or  papier  tinge,  consists  of 
paper  made  to  resemble  damask  and 
other  linen  so  closely,  that  it  is  impossi- 
ble, without  examination,  to  detect  the 
difference  :  and,  even  to  the  touch,  the 
articles  made  from  the  papier  linge  are 
very  much  like  linen.  The  price  is  very 
low :  a  napkin  costs  only  one  cent ; 
and,  when  they  are  soiled,  they  are  taken 
back  at  half  price.  A  good-sized  table- 
cloth sells  for  20  cents,  and  for  the  same 
price  is  sold  a  rouleau  of  paper,  with  one 


or  two  colors,  for  papering  rooms,  or  for 
bed-curtains. 

Oiled  paper.  Dr.  Faraday,  in  his  ad- 
mirable volume  on  manipulations,  states 
that  hydrogen  gas  may  be  made  with 
zinc,  and  dilute  sulphuric  acid  in  oiled 
paper,  and  conducted  through  paper 
tubes  to  a  basin,  as  a  trough,  and  re- 
ceived in  oiled  paper  tubes.  Also,  that 
the  steam  of  a  tea-kettle  may  be  con- 
veyed in  oiled  paper  tubes,  so  as  to  heat 
a  steam-bath  itself  of  oiled  paper. 

Paper  tubes,  to  convey  hot  air,  carbonic 
acid,  or  coal  gas,  may  be  made  by  rolling 
a  sheet  of  paper,  and  tying  it  with  thread. 
Gum,  or  paste,  at  the  edges,  makes  it  air- 
tight, especially  if  varnished  and  corked. 
Waxed  paper. — Lay  it  on  a  clean  hot 
plate,  and  rub  it  with  wax  tied  in  muslin. 
Paper-hangings  are  in  pieces  of  12 
yards  long,  by  20  inches  wide,  and  prints 
ed  by  wooden  blocks,  with  great  rapidity. 
It  is  to  be  regretted  that  the  splendid 
scenes  and  varied  colors  of  French  paper- 
hangings  are  not  imitated  elsewhere. 

Sea-grass  paper. — 1,  All  rocks,  roots, 
and  shells,  to  be  carefully  separated  from 
the  grass.  2,  The  dust  to  be  cleared  from 
it,  by  beating  it.  8,  To  be  steeped  in  lime- 
water,  in  order  to  discharge  tne  salt  from 
it,  and  thus  prevent  decomposition.  4, 
To  be  partially  pulverized,  and  then 
bleached  perfectly  white  by  oxy-muriate 
of  lime.  5,  To  be  made  into  pulp  in  the 
usual  manner,  by  beating,  or  in  a  paper- 
engine. 

PAPER  PLOUGHING -MACHINE. 
This  consists  of  a  stout  square  board,  the 
size  of  the  paper,  when  cut ;  furnished, 
on  the  upper  surface,  with  four  deep 
grooves,  one  on  each  of  the  four  sides, 
for  guiding  the  plough.  The  plough  it- 
self is  of  a  peculiar  construction,  in  two 
parts  ;  one  part  squaring  upon  the  edge, 
and  in  the  groove  of  the  board ;  while 
the  second  portion  carries  the  knife,  and 
moves  upon  the  first  in  a  vertical  direc- 
tion. The  paper  to  be  cut  being  placed 
upon  the  cutting- bench,  under  the 
grooved  board,  the  latter  is  brought 
down  upon  the  paper  by  an  iron-screwed 
rod,  working  between  the  board  and  a 
beam  over  head.  The  paper  being  firmly 
secured,  and  the  upper  board  forming 
the  srauge  by  which  it  is  to  be  cut,  the 
workman  places  the  plough  in  one  of  the 
grooves,  and  moving  it  to  and  fro  in  an 
horizontal  direction,"  effects  the  cutting 
of  one  edge  of  the  paper ;  the  plough  is 
then  transferred  to  another  groove,  and 
a  second  edge  cut ;  a  similar  operation 
with  the  third  edge  completes  the  object. 


PAPJ 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


431 


As  the  paper  is  cut  away,  the  knife  de- 
scends, until  the  whole  is  taken  off,  and 
the  parallelism  of  the  knife  is  accurately 
maintained  throughout ;  in  this  way  the 
three  sides  of  the  paper  are  expeditiously 
cut,  with  one  adjustment  only ;  nor  is 
the  difficulty  of  putting  in  the  paper  so 
great  as  in  the  binders'  common  cutting- 
press. 

PAPER  HANGINGS.  This  import- 
ant and  elegant  substitute  for  the  an- 
cient "hangings"  of  tapestry  or  cloth  came 
into  use  about  200  years  ago.  The  manu- 
facture has  undergone  a  gradual  succes- 
sion of  improvements,  and  has  now 
reached  a  high  state  of  beauty  and  per- 
fection. The  patterns  on  these  papers 
are  sometimes  produced  by  stencil  plates, 
but  more  commonly  by  blocks,  each  color 
being  laid  on  by  a  separate  block  cut  in 
wood  or  metal  upon  a  plain  or  tinted 
ground.  The  patterns  are  sometimes 
printed  in  varnish  or  size,  and  gilt  or 
copper  leaf  applied ;  or  bisulphuret  of 
tin  (durum  mvsivum)  is  dusted  over  so 
as  to  adhere  to  the  pattern  ;  and  in  what 
are  called  flock  pagers,  dyed  wools  minced 
into  powder  are  similarly  applied.  Pow- 
dered steatite,  or  French  chalk,  is  used 
to  produce  the  peculiar  gloss  known 
under  the  name  ot  satm.  Striped  papers 
are  sometimes  made  by  passing  the  paper 
rapidly  under  a  trough,  which  has  par- 
allel slits  in  its  bottom  through  which  the 
color  is  delivered ;  and  a  number  of  other 
very  ingenious  and  beautiful  contrivances 
have  lately  been  applied  in  this  impor- 
tant branch  of  art.  The  invention  of  the 
paper  machine,  by  which  any  length  of 
paper  may  be  obtained,  effected  a  great 
change  in  paper  hangings,  which  could 
formerly  only  be  printed  upon  separate 
sheets,  and  were  much  more  inconveni- 
ent to  print  as  well  as  to  apply  to  the 
walls. 

Originally  the  first  method  of  making 
this  paper  was  stencilling ;  by  laying 
upon  it,  in  an  extended  state,  a  piece  of 
pasteboard  having  spaces  cut  out  of  vari- 
ous figured  devices,  and  applying  diffe- 
rent water  colors  with  the  brush.  An- 
other piece  of  pasteboard  with  other  pat- 
terns cut  out  was  next  applied,  when  the 
former  figures  were  dry,  and  new  designs 
were  thus  imparted.  By  a  series  of  such 
operations,  a  tolerable  pattern  was  execut- 
ed, but  with  no  little  labor  or  expense. 
The  processes  of  the  calico  printer  were 
next  resorted  to,  in  which  engraved 
blocks  of  the  pear  or  sycamore  were  em- 
ployed to  impress  the  colored  designs. 

Paper-hangings  may  be  distinguished 


into  two  classes ;  1.  those  which  are 
really  painted,  and  which  are  designed 
in  France  under  the  title  of  papiers  pei7its, 
with  brilliant  flowers  and  figures ;  and  2. 
those  in  which  the  designs  are  formed  by 
foreign  matters  applied  to  the  paper, 
under  the  name  of  papier  tontisse,  or  flock 
paper. 

The  operations  common  to  paper-hang- 
ings of  both  kinds,  may  be  stated  as  fol- 
lows : 

1.  The  paper  should  be  well  sized. 

2.  The  edges  should  be  evenly  cut  by 
an  apparatus  like  the  bookbinder's 
press. 

3.  The  ends  of  each  of  the  24  sheets 
which  form  a  piece,  should  be  nicely 
pasted  together;  or  a  Fourdrinier  web 
of  paper  should  be  taken. 

4.  Laying  the  grounds,  is  done  with 
earthy  colors  or  colored  lakes  thickened 
with  size,  and  applied  with  brushes. 

An  expert  workman,  with  one  or  two 
children,  can  lay  the  grounds  of  300 
pieces  in  a  day.  The  pieces  are  now  sus- 
pended upon  poles  near  the  ceiling,  in 
order  to  be  dried.  They  are  then  rolled 
up  and  carried  to  the  apartment  where 
they  are  polished,  by  being  laid  upon  a 
smooth  table,  with  the  painted  side  un- 
dermost, and  rubbed  with  the  polisher. 
Pieces  intended  to  be  satined,  are  ground- 
ed with  fine  Paris  plaster,  instead  of 
Spanish  white,  and  are  not  smoothed 
with  a  brass  polisher,  but  with  a  hard 
brush  attached  to  the  lower  end  of  the 
swing  polishing  rod.  After  spreading  the 
piece  upon  the  table  with  the  grounded 
side  undermost,  the  paper-stainer  dusts 
the  upper  surface  with  finely  powdered 
chalk  of  Briancon,  commonly  called  calc, 
and  rubs  it  strongly  with  the  brush.  In 
this  way  the  satiny  lustre  is  produced. 

The  laying  on  of  colors  is  accomplished 
in  precisely  the  same  way  as  in  calico 
printing,  either  by  block  press  printing, 
or  by  the  cylinder  machine.  With  the 
latter,  18,000  yards  a  day  are  printed ; 
these  are  afterwards  cut  into  pieces  12 
yards  long.  The  great  length  to  which 
paper  is  now  made,  in  some  cases  2,800 
feet  long,  facilitates  very  much  the  work- 
ing of  this  machine. 

PAPIER-MACHE.  A  name  given  to 
articles  manufactured  of  the  pulp  of 
paper,  or  of  old  paper  ground  up  into  a 
pulp,  bleached,  if  necessary,  and  mould- 
ed into  various  forms.  This  article  has 
lately  been  used  upon  an  extensive  scale 
for  the  manufacture  of  mouldings,  ros- 
ettes, and  other  architectural  ornaments ; 
pilasters,   capitals,  and  even  figures  as 


432 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[par 


large  as  life,  have  also  been  made  of  it. 
It  is  lighter,  more  durable,  and  less 
brittle  and  liable  to  damage  than  plaster, 
and  admits  of  being  colored,  gilt,  or 
otherwise  ornamented.  Another  article 
sometimes  goes  under  the  same  name 
which  is  more  like  pasteboard,  consisting 
of  sheets  of  paper  pasted  or  glued,  and 
powerfully  pressed  together,  so  as  to  ac- 
quire, when  dry,  the  hardness  which  it 
possesses.  It  is  afterwards  varnishei 
with  japan  or  other  varnish,  and  often 
beautifully  ornamented  by  figures,  land- 
scapes, &c,  occasionally  inlaid  with 
mother  of  pearl ;  a  mixture  of  copperas, 
quicklime,  and  glue,  makes  it  partially 
waterproof;  and  borax  and  phosphate 
of  soda,  which  is  also  added,  tends  to 
make  it  fire-proof. 

PAPIER  VEGETABLE.  The  best 
kind  of  tracing  paper,  permitting  either 
the  use  of  ink  or  black-lead  pencil ;  be- 
sides being  of  a  purer  color  than  any 
other,  is  obtained  in  France  from  the 
root  of  the  altho&a  officinalis. 

PARAFINE.  A  substance  contained 
in  the  products  of  the  distillation  of  the 
tar  of  beech  wood.  It  is  a  tasteless  in- 
odorous fatty  matter,  fusible  at  112°,  and 
resists  the  action  of  acids  and  alkalis.  It 
appears  to  be  a  hydro-carbon.  Its  name 
is  compounded  of  parum,  little,  andaffinis, 
akin,  to  denote  the  remarkable  chemical 
indifference  which  is  its  characteristic 
feature.  A  similar  substance  has  been 
obtained  by  Dr.  Christison  from  the 
petroleum  of  Rangoon. 

PARACHUTE.  An  apparatus  resemb- 
ling the  common  umbrella,  but  of  far 
greater  extent,  intended  to  enable  an 
aeronaut,  in  case  of  alarm,  to  drop  from 
his  balloon  to  the  ground  without  sus- 
taining injury.  This  is  effected  by  means 
of  the  resistance  of  the  atmosphere. 
When  the  parachute  is  detached  from 
the  balloon,  and  abandoned  with  its  load 
in  the  air,  it  must  proceed  at  first,  from 
the  continued  action  of  gravity,  with  an 
accelerated  motion,  until  the  increased 
velocity  produces  a  resistance  equal  to 
the  force  of  attraction,  or  the  weight  of 
the  apparatus  with  its  load.  After  this 
equilibrium  has  been  attained,  the  para- 
chute will  descend  with  a  nearly  uniform 
velocity.  According  to  theory,  this  ter- 
minal velocity,  supposing  the  surface  of 
the  parachute  to  be  flat,  is  equal  to  that 
which  a  heavy  body  would  acquire  in 
falling  though  the  altitude  of  a  column  of 
air  incumbent  on  that  surface,  and  hav- 
ing the  same  weight  as  the  whole  appar- 
atus. A  circular  parachute  having  a  diam- 


eter of  30  feet,  and  weighing  with  its  load 
225  pounds,  would  acquire  a  terminal 
velocity  of  about  13  feet  per  second ;  and 
a  person  descendiug  with  it  at  this  rate 
would  receive  the  same  shock  on  reach  - 
i  ing  the  ground  as  if  he  dropped  freely 
from  a  height  of  2|  feet.  The  actual  re- 
sistance of  the  air  is,  however,  greater 
!  than  is  given  by  theory,  and  is,  besides, 
|  augmented  by  the  concavity  of  the  para- 
chute, which  occasions  an  accumulation 
of  the  fluid;  but,  on  account  of  the  ac- 
tion of  the  wind,  the  axis  of  the  para- 
chute will  probably  become  inclined  to 
the  vertical,  in  which  case  the  resistance 
will  suffer  a  diminution. 

One  of  the  most  remarkable  instances 
of  descent  from  a  great  height  with  a 
parachute  is  that  of  Garnerin,  a  French- 
man, who  ascended  in  a  balloon  from 
London,  on  the  2nd  of  September,  1802. 
After  hovering  seven  or  eight  miuutes  in 
the  atmosphere,  he  cut  the  cord  by  which 
his  parachute  was  attached  to  the  bal- 
loon. It  instantly  expanded,  and  for 
some  seconds  descended  with  an  acceler- 
ating velocity,  till  it  became  tossed  ex- 
tremely, and  took  such  wide  oscillations 
that  the  basket  or  car  was  at  times  thrown 
almost  into  a  horizontal  position.  The 
intrepid  aeronaut  narrowly  escaped  de- 
struction by  being  precipitated  on  the 
houses  in  St.  Pancras,  and  at  last  fortun- 
ately came  to  the  ground  in  a  neighbor- 
ing field.  He  seemed  to  be  much  agitated, 
and -trembled  exceedingly  at  the  moment 
he  was  released  from  the  car. 

A  recent  experiment  of  this  kind,  made 
by  Mr.  Cocking,  was  attended  with  fatal 
consequences.  Having  conceived  a  no- 
tion that  the  vibration  might  be  avoided 
by  giving  the  machine  a  different  form, 
this  projector  constructed  one  in  the  form 
of  an  inverted  umbrella,  that  is,  having 
the  concave  side  uppermost,  and  bound 
to  a  strong  wooden  hoop  to  prevent  its 
collapse  in  the  descent.  The  diameter  of 
the  hoop  was  34  feet ;  and  there  was  also 
a  hole  of  6  feet  in  diameter  in  the  middle 
of  the  parachute,  which,  it  was  supposed, 
would  also  contribute  to  give  greater 
steadiness.  Having  attached  himself  to 
this  machine,  he  ascended  from  Vauxhall 
Gardens  on  the  24th  of  July,  1837.  On 
being  cut  away  from  the  balloon  the  para- 
chute descended  rapidly,  and  with  violent 
oscillations  :  the  hoop  broke,  and  the  un 
i  fortunate  projector  fell,  dreadfully 
J  mangled,  at  Lee,  near  Blackheath.  The 
persons  in  the  car  of  the  balloon  were 
also  placed  in  great  danger,  having  nar- 
I  rowly  escaped  suffocation  from  the  quan- 


par] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


453 


tity  of  gas  expelled  in  consequence  of  the 
great  velocity  with  which  the  balloon 
darted  upwards  immediately  on  being 
liberated  from  the  parachute.  They  suf- 
fered extreme  pain,  and  for  a  time  were 
deprived  of  sight ;  but  fortunately  they 
had  carried  up  with  them  a  large  bag 
filled  with  atmospheric  air,  by  means  of 
which  they  were  enabled  to  breathe. 
Without  this,  they  would  probably  have 
perished.  Since  then  safe  descents  have 
been  made  with  the  parachute  both  in 
England  and  France. 

Latterly,  use  has  been  made  of  these 
instruments  in  making  descents  in  coal 
mines.  Occasionally  the  rope  breaks  and 
injury  arises.  By  one  of  these  being 
attached,  when  an  accident  occurs  it  un- 
furls, and  breaking  the  force  of  the  fall 
enables  those  descending  to  reach  the 
bottom  in  security. 

PARAPET,  or  BREAST-WORK.  In 
fortification,  a  wall  or  screen  raised  on 
the  extreme  edge  of  a  rampart  or  other 
work,  through  which  embrasures  or  op- 
enings are  cut  for  the  cannons  to  fire 
through.  The  solid  parts  of  the  parapet, 
between  the  embrazures,  are  called  the 
merlons.  In  common  language,  a  para- 
pet is  a  breast- wall,  raised  on  the  edges 
of  bridges,  quays,  <fec,  to  prevent  people 
from  falling  over. 

PARALLEL  MOTION  is  a  very  im- 
portant principal  in  mechanics ;  that  by 
which  the  motion  of  a  piston  is  rendered 
a  rotatory  action,  and  a  rotatory  motion  a 
rectilinear  one  ;  so  that,  if  we  get  power, 
we  may,  by  this  means,  apply  it  in  the 
way  desired.  The  crank  ot  the  old  spin- 
ning-wheel is  the  most  common  method, 
but  it  causes  the  piston-rod  to  wabble. 
To  prevent  this  wabbling  has  been  the 
subject  of  much  contrivance.  White's 
American  is  most  ingenious.  He  con- 
nects the  piston  with  the  inner  of  two 
wheels,  which  works  inside  an  outer  one 
of  double  its  size,  and  goes  twice  round 
the  outer,  in  an  epicycloid  equal  to  the 
diameter  of  the  outer,  which  is  upon  an 
axis  connected  with  the  works.  Another 
plan  is,  to  connect  the  piston-rod  by  a 
bar,  with  a  rotating  crank,  which  re- 
volves the  axle. 

PARING  AND  BURNING.  The 
operation  of  paring  off  the  surface  of 
worn-out  grass  land,  or  lands  covered 
with  coarse  herbage,  and  burning  it  for 
the  sake  of  the  ashes,  and  for  the  destruc- 
tion of  weeds,  seeds,  insects,  &c.  Agri- 
culturists differ  as  to  the  value  of  this 
mode  of  improving  land ;  the  greater 
number  preferring  a  naked  fallow  even 
19 


for  one  or  two  years,  alleging  that  moro 
injury  is  done'by  the  vegetable  matter 
lost  in  burning,  than  benefit  obtained  by 
the  ashes  produced.  Where  the  object 
is  to  bring  land  abounding  in  coarse 
herbage  immediately  into  a  state  of  good 
culture,  paring  and  burning  is  evidently 
the  most  rapid  mode  that  can  be  em- 
ployed ;  and  if  the  soil  contains  calcare- 
ous matter,  burning  will  have  nearly  the 
same  effect  on  it  as  if  a  dressing  of  quick- 
lime had  been  applied.  Much,  however, 
depends  on  the  way  the  land  is  treated 
afterwards. 

Whether  land  requires,  and  will  be 
benefitted  by  paring  and  burning,  de- 
pends upon  its  condition:  if  it  be  full  of 
weeds,  and  have  an  abundance  of  vegeta- 
ble matter,  and  especially  if  that  organic 
matter  be  in  an  acid  and  sour  state,  or 
in  any  way  peaty,  then  paring  and  burn- 
ing the  soil  will  be  a  great  means  of  fer- 
tilizing the  land ;  but  it  is  a  great  im- 
poverishes and  should  never  supply  the 
place  of  manure,  nor  should  it  be  practis- 
ed except  under  the  above  conditions. 

PARCHMENT.  This  writing  material 
has  been  known  since  the  earliest  times, 
but  is  now  made  in  a  very  superior  man- 
ner to  what  it  was  anciently.  The  art  of 
making  parchment  consists  in  certain 
manipulations  necessary  to  prepare  the 
skins  of  animals  of  such  thinness,  flex- 
ibility and  firmness,  as  may  be  required 
for  the  different  uses  to  which  this  sub- 
stance is  applied.  Though  the  skins  of 
all  animals  might  be  converted  into 
writing  materials,  only  those  of  the  sheep 
or  the  she-goat  are  used  for  parchment ; 
those  of  calves,  kids,  and  dead-born 
lambs  for  vellum ;  those  of  the  he-goat, 
she-goat,  and  wolves  for  drum-heads ; 
and  those  of  the  ass  for  battle-doors.  All 
these  skins  are  prepared  in  the  same 
way,  with  slight  variations. 

They  are  first  of  all  prepared  by  the 
leatheivdresser.  After  they  are  taken  out 
of  the  lime-pit,  shaved,  and  well  washed, 
they  must  be  set  to  dry  in  such  a  way  as 
to  prevent  their  puckering,  and  to  render 
them  easily  worked.  The  small  manu- 
facturers make  use  of  hoops  for  this  pur- 
pose, but  the  greater  employ  a  herse,  or 
stout  wooden  frame.  This  is  formed  of 
two  uprights  and  two  cross-bars  solidly 
joined  together  by  tenons  and  mortises, 
so  as  to  form  a  strong  piece  of  carpentry, 
which  is  to  be  fixed  up  against  a  wall. 
These  four  bars  are  perforated  all  over 
with  a  series  of  holes,  of  such  dimensions 
as  to  receive  slighdy  tapered,  box-wood 
pins,  truly  turned,  or  even  iron  bolts. 


434 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pas 


Each  of  these  pins  is  transpierced  with  a 
hole  like  the  pin  of  a  violin,  by  means  of 
which  the  strings  employed  in  stretch- 
ing the  skin  may  be  tightened.  Above 
the  Jierse  a  shelf  is  placed  for  receiving 
the  tools  which  the  workman  needs  to 
have  always  at  hand.  In  order  to  stretch 
the  skin  upon  the  frame,  larger  or  smaller 
skewers  are   employed,   according  as   a 

freater  or  smaller  piece  of  it  is  to  be  laid 
old  of.  Six  holes  are  made  in  a  straight  line 
to  receive  the  larger,  and  four  to  receive 
the  smaller  skewers  or  pins.  These  small 
slits  are  made  with  a  tool  like  a  carpen- 
ter's chisel,  and  of  the  exact  size  to  admit 
the  skewer.  The  string  round  the  skewer 
is  affixed  to  one  of  the  bolts  in  the  frame, 
which  are  turned  round  by  means  of  a 
key,  like  that  by  which  pianos  and  harps 
are  tuned.  The  skewer  is  threaded 
through  the  skin  in  a  state  of  tension. 

Every  thing  being  thus  prepared,  and 
the  skin  being  well  softened,  the  work- 
man stretches  it  powerfully  by  means  of 
the  skewers ;  he  attaches  the  cords  to  the 
skewers,  and  fixes  their  ends  to  the  iron 
pegs  or  pins.  He  then  stretches  the  skin, 
first  with  his  hand  applied  to  the  pins, 
and  afterwards  with  the  key.  Great  care 
must  be  taken  that  no  wrinkles  are 
formed.  The  skin  is  usually  stretched 
more  in  length  than  in  breadth,  from  the 
custom  of  the  trade  ;  though  extension  in 
breadth  would  be  preferable,  in  order  to 
reduce  the  thickness  of  the  part  opposite 
the  backbone. 

The  workman  now  takes  the  fleshing 
tool  represented  under  Currying.  It  is  a 
semicircular  double-edged  knife,  made 
fast  into  a  double  wooden  handle.  The 
workman  seizes  the  tool  in  his  two  hands, 
so  as  to  place  the  edge  perpendicularly 
to  the  skin,  and  pressing  it  carefully 
from  above  downwards,  removes  the 
fleshy  excrescences,  and  lays  them  aside 
for  making  glue.  He  now  turns  round 
the  herse  upon  the  wall,  in  order  to  get 
access  to  the  outside  of  the  skin,  and  to 
scrape  it  with  the  tool  inverted,  so  as  to 
run  no  risk  of  cutting  the  epidermis.  He 
thus  removes  any  adhering  filth,  and 
squeezes  out  some  water.  The  skin  must 
next  be  ground.  For  this  purpose  it  is 
sprinkled  upon  the  fleshy  side  with  sifted 
chalk  or  slaTced  lime,  and  then  rubbed  in 
all  directions  with  a  piece  of  pumice- 
stone,  4  to  5  inches  in  area,  previously 
flattened  upon  a  sandstone.  The  lime 
gets  soon  moist  from  the  water  contained 
in  the  skin.  The  pumice-stone  is  then 
rubbed  over  the  other  side  of  the  skin, 
but  without  chalk  or  limo.    This  opera- 


tion is  necessary  only  for  the  best  parch- 
ment or  vellum.  The  skin  is  now  allow- 
ed to  dry  upon  the  frame ;  being  care- 
fully protected  from  sunshine,  and  from 
frost.  It  is  afterwards  scraped,  rubbed, 
and  polished  with  pumice.  It  is  occa- 
sionally colored  green  with  a  mixture  of 
cream  of  tartar,  verdigris,  and  nitric 
acid,  and  finally  receives  a  gloss  from 
the  white  of  egg  or  mucilage,  laid  on 
with  a  brush. 

PARTING.  A  process  for  separating 
gold  from  silver.  (See  Assat,  Eekining, 
and  Silver.) 

PASTE.  In  gem  sculpture  a  prepara- 
tion of  glass,  calcined  crystal,  lead,  and 
other  ingredients,  for  imitating  gems. 
This  art  was  well  known  to  the  ancients, 
and  after  being  long  lost,  was  restored,  at 
the  end  of  the  fifteenth  century,  by  a 
Milanese  painter. 

Some  modern  artists  have  succeeded 
in  obtaining  a  composition  pessessing  a 
hard,  fine,  and  brilliant  lustre  or  appear- 
ance ;  but  pastes,  or  mock  diamonds  as 
they  are  called,  depend  most  for  brilli- 
ancy on  the  art  displayed  in  setting  the 
foil  or  tinsel  behind  them.  Several  re- 
cipes have  been  given  by  M.  Fontanier ; 
but  the  most  useful,  and  that  generally 
employed  for  the  production  ot  artificial 
diamonds,  is  the  following:  Take  of 
litharge  20  parts,  of  silex  12,  of  nitre  4, 
of  borax  4,  and  of  white  arsenic  2  parts. 
These  ingredients  are  to  be  well  mixed 
together  in  a  crucible  and  melted;  the 
fused  metal  is  thrown  into  water;  and 
should  any  of  the  lead  employed  be  re- 
duced to  the  metallic  state,  it  becomes 
separated  by  this  process  and  the  glass  is 
remelted  for  use.  For  the  finer  kinds 
rock  crystal  is  used  instead  of  flint  or 
sand,  as  it  occurs  in  a  much  purer  state  ; 
i.  £.,  more  free  from  the  admixture  ot 
metallic  oxides,  which  give  to  vitreous 
compounds  their  different  colors.  In 
place  of  the  above,  Loysel  recommends 
the  following  ingredients  to  form  a  com- 
pound, having  the  same  specific  gravity 
as  the  oriental  diamond,  and  on  this  ac- 
count considered  superior,  as  it  more 
nearly  approaches  the  gem  with  regard 
to  its  refractive  and  dispersive  powers; 
but,  like  the  former,  it  requires  to  be 
kept  for  some  two  or  three  days  in  a  fused 
state,  in  order  to  expel  the  superabun- 
dant alkali  and  to  perfect  the  refining.  A 
moderate  degree  of  heat  fuses  it.  The 
following  is  its  composition :  Take  of 
white  sand  purified  by  being  washed, 
first  in  muriatic  acid,  and  afterwards  in 
pure  water,  until  all  traces  of  acid  are  re- 


pas] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


435 


moved,  100  parts;  red  oxide  ef  lead 
(minium)  150  parts;  calcined  potash  30 
to  35  parts ;  calcined  borax  10 ;  and 
oxide  of  arsenic  1  part. 

The  term  paste  is  also  applied  to  the 
earthy  mixture  for  pottery  and  porce- 
lain ;  also  to  dough,  and  to  the  solution 
of  starch  or  wheat  flour,  made  by  first 
mixing  it  with  a  proper  portion  of  cold 
water,  and  then  adding  boiling  water 
under  constant  stirring,  so  as  to  form  an 
even  solution.  Alum  is  often  added  to 
paste  to  strengthen  it. 

PASTEL.  In  painting,  a  crayon  formed 
with  any  color  and  gum  water,  for  paint- 
ing on  paper  or  parchment.  The  great 
defect  of  this  mode  of  painting  is  its  want 
of  durability.     (See  Crayon). 

PASTIL.  In  pharmacy,  a  kind  of 
lozenge.  A  compound  of  charcoal  with 
odoriferous  substances,  which  diffuses 
an  agreeable  perfume  during  its  slow 
combustion. 

PASTES,  or  FACTITIOUS  GEMS. 
The  general  vitreous  body  called  Strass 
(from  the  name  of  its  German  inventor,) 
preferred  by  Fontanier,  is  prepared  in 
the  following  manner : — 8  ounces  of  pure 
rock-crystal  or  flint  in  powder,  mixed 
with  24  ounces  of  salt  of  tartar,  are  to  be 
baked  and  left  to  cool.  The  mixture  is 
to  be  afterwards  poured  into  a  basin  of 
hot  water,  and  treated  with  dilute  nitric 
acid  till  it  ceases  to  effervesce  ;  and  then 
the  frit  is  to  be  washed  till  the  water 
comes  off  tasteless.  This  is  to  be  dried, 
and  mixed  with  12  ounces  of  fine  white 
lead,  and  the  mixture  is  to  be  levigated 
and  elutriated  with  a  little  distilled  water. 
An  ounce  of  calcined  borax  being  added 
to  about  12  ounces  of  the  preceding  mix- 
ture in  a  dry  state,  the  whole  is  to  be 
rubbed  together  in  a  porcelain  mortar, 
melted  in  a  clean  crucible,  and  poured 
out  into  cold  water.  This  vitreous  mat- 
ter must  be  dried,  and  melted  a  second 
and  a  third  time,  always  in  a  new  crucible, 
and  after  each  melting  poured  into  cold 
water,  as  at  first,  taking  care  to  separate 
the  lead  that  may  be  revived.  To  the 
third  frit,  ground  to  powder,  5  drachms 
of  nitre  are  to  be  added ;  and  the  mix- 
ture being  melted  for  the  last  time,  a 
mass  of  crystal  will  be  found  in  the  cru- 
cible, of  a  beautiful  lustre.  The  diamond 
may  be  well  imitated  by  this  Mayence 
base.  Another  very  fine  white  crystal 
may  be  obtained,  according  to  M.  Fon- 
tanier, from  8  ounces  of  white  lead,  2 
ounces  of  powdered  borax,  i  grain  of  man- 
ganese, and  3  ounces  of  rock-crystal, 
treated  as  above. 


The  colors  of  artificial  gems  arc  obtain- 
ed from  metallic  oxides.  The  oriental 
topaz  is  prepared  by  adding  oxide  of  an- 
timony to  the  base;  the  amethyst,  by 
manganese  with  a  little  of  the  purple  of 
Cassius;  the  beryl,  by  antimony  and  a 
very  little  cobalt;  yellow  artificial  dia- 
mond and  opal,  by  horn-silver  (chloride 
of  silver ;)  blue-stone  or  sapphire,  by 
cobalt.  The  following  proportions  have 
been  given : — 

For  the  yellow  diamond.  To  1  ounce 
of  strass,  add  24  grains  of  chloride  of  sil- 
ver, or  10  grains  of  glass  of  antimony. 

For  the  sapphire.  To  24  ounces  of 
strass,  add  2  drachms  and  26  grains  of 
the  oxide  of  cobalt. 

For  the  oriental  ruby.  To  16  ounces 
of  strass,  add  a  mixture  of  2  drachms  and 
48  grains  of  the  precipate  of  Cassius,  the 
same  quantity  of  peroxide  of  iron  prepar- 
ed by  nitric  acid,  the  same  quantity  of 
golden  sulphuret  of  antimony  and  of  man- 
ganese calcined  with  nitre,  and  2  ounces 
of  rock  crystal.  Manganese  alone,  com- 
bined with  the  base  in  proper  quantity, 
is  said  to  give  a  ruby  color. 

For  the  anierald.  To  15  ounces  of 
strass,  add  1  drachm  of  mountain  blue 
(carbonate  of  copper),  and  6  grains  of 
glass  of  antimony  ;  or,  to  1  ounce  of  base, 
add  29  grains  of  glass  of  antimony,  and  3 
grains  of  oxide  of  cobalt. 

For  the  common  opal.  To  1  ounce  of 
strass,  add  10  grains  of  horn-silver,  2 
grains  of  calcined  magnetic  ore,  and  26 
grains  of  an  absorbent  earth  (probably 
chalk-marl.) 

M.  Douault  Wieland,  in  an  experiment- 
al memoir  on  the  preparation  of  artificial 
colored  stones,  has  offered  the  following 
instructions,  as  being  more  exact  than 
what  were  published  before. 

The  base  of  all  artificial  stones  is  a  col- 
orless glass,  which  he  calls  fondant,  or 
flux  ;  and  he  unites  it  to  metallic  oxides, 
in  order  to  produce  the  imitations.  If  it 
be  worked  aJone  on  the  lapidary's  wheel, 
it  counterfeits  brilliants  and  rose  dia- 
monds remarkably  well. 

This  base  or  strass  is  composed  of  silex, 
potash,  borax,  oxide  of  lead,  and  some- 
times arsenic.  The  silicious  matter  should 
be  perfectly  pure;  and  if  obtained  from 
sand,  it  ought  to  be  calcined  and  washed, 
first  with  dilute  muriatic  acid  and  then 
with  water.  The  crystal  or  flint  should 
be  made  rcdhot,  quenched  in  water,  and 
ground,  as  in  the  potteries.  The  potash 
should  be  purified  from  the  best  pearl- 
ash  ;  and  the  borax  should  be  refined  by 
one  or  two  crystallizations.    The  oxide  of 


436 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pat 


lead  should  bo  absolutely  free  from  tin, 
for  the  least  portion  of  this  latter  metal 
causes  milkiness.  Good  red  lead  is  pre- 
ferable to  litharge.  The  arsenic  should 
also  be  pure.  Hessian  crucibles  are  pre- 
ferable to  those  of  porcelain,  for  they  are 
not  so  apt  to  crack  and  run  out.  Either 
a  pottery  or  porcelain  kiln  will  answer, 
and  the  fusion  should  be  continued  24 
hours  ;  for  the  more  tranquil  and  contin- 
uous it  is,  the  denser  is  the  paste,  and 
the  greater  its  beauty. 

For  rubies,  the  proportions  are : — Paste 
2,800 ;  oxide  manganese  70. 

For  emerald  :— -Paste  4,608 ;  green  ox- 
ide copper  42 ;  oxide  crome  2. 

PATENT  YELLOW.  A  pigment  ob- 
tained by  fusing  a  mixture  of  oxide  and 
chloride  of  lead. 

'  PAVEMENT  FOR  ROADS.  As  the 
advantages  of  good  roads  through  the 
country  are  unquestionable,  so  the  bene- 
fits of  well  paved  streets  in  cities  are  no 
less  apparent.  Good  roads  are  an  evi- 
dence of  civilization.  The  Indian  follows 
the  trail  of  his  forefather,  and  gives  evi- 
dence of  some  kindred  instinct  like  the 
brute,  but  the  civilized  man  levels  the 
mountain  and  fills  up  the  morass,  to  make 
a  permanent  pathway  for  the  horse  and 
his  rider,  the  carriage  and  its  driver.  The 
importance  of  good  roads  was  not  un- 
known to  the  ancients,  and  to  the  Car- 
thagenians,  a  commercial  people,  is  the 
invention  of  paved  roads  traced.  From 
them  the  Romans  learned  the  art  as  they 
did  that  of  ship-building.  During  the 
reign  of  Julius  Cassar,  the  Capital  was  in 
communication  with  the  chief  towns  by 
well  paved  roads  which  branched  from 
the  seven-hilled  city,  at  one  time,  to  every 
province  of  the  empire.  The  Romans 
introduced  their  system  of  roads  into 
Britain,  and  they  were  made  upon  a 
gigantic  scale,  with  an  eye  to  permanency, 
it  being  the  common  opinion  then  that 
the  Roman  Empire  was  to  endure  for 
ever. 

The  Perrine  pavement  lately  laid  down 
in  New-York  is  a  pavement  made  of  ob- 
long blocks  of  trap,  each  of  about  10  inches 
long,  and  six  broad,  and  six  deep,  neatly 
trimmed.  The  ground  is  excavated  about 
14  inches,  and  a  strata  of  4  inches  gravel 
mixed  with  sand  and  some  plaster  of 
Paris  is  laid  down  and  well  beetled  and 
levelled  and  then  sprinkled  with  water. 
Then  another  strata  is  laid  down  of  the 
same  stuff  and  treated  in  the  same  way, 
making  it  slightly  convex.  On  the  top 
/of  this  these  oblong  blocks  are  laid  in 
among  a  bed  of  sand  mixed  with  ground 


burnt  brick.  These  blocks  must  be  ac- 
curately laid  and  well  rammed  down,  and 
in  our  opinion  will  make  the  best  pave- 
ment for  a  business  city  like  New-York, 
where  there  is  an  immense  amount  of 
travel. 

The  idea  of  paving  the  streets  of  mod- 
ern cities  is  derived  from,  and  based  upon 
the  Roman  roads.  Many  of  these  are  still 
in  perfect  repair  in  Italy,  especially  in 
the  neighborhood  of  Rome.  The  stones 
are  generally  of  trap  rock,  of  a  polyangu- 
lar  shape,  of  a  very  large  surface,  and 
about  fourteen  inches  deep.  They  are 
slightly  pyramidal,  and  set  with  their 
broad  faces  upwards.  They  are  well  fit- 
ted together,  and  sometimes  laid  in  ce- 
ment, though  not  always.  In  Naples, 
the  blocks  are  rectangular  (mostly 
square)  of  about  two  feet,  by  two  surface, 
and  six  inches  in  thickness,  well  fitted  to- 
gether, placed  diagonally  on  the  street, 
and  laid  in  a  thick  hed  or  Roman  cement. 
This  pavement  excels  in  solidity  and  even- 
ness, but  becomes  dangerously  smooth, 
hence  it  is  necessary,  from  time  to  time  to 
cut  grooves  on  its  surface.  The  city  of 
Rome  is  paved  with  blocks  which '  are 
parallelograms,  of  about  ten  inches  square 
surface.  They  are  laid  in  a  thick  bed  of 
cement.  In  the  cities  of  Northern  Italy, 
the  roads  may  be  called  stone  railroads, 
as  the  tracks  for  the  wheels  are  broad  flat 
stones,  laid  with  precision,  while  the 
tracks  for  the  horses'  feet,  between  the 
lines,  are  paved  with  small  stones.  This 
is  a  good  pavement,  when  well  made,  and 
was  partially  carried  out  on  the  great 
turnpike  between  the  cities  of  Albany  and 
Schenectady,  in  New-York.  None  of 
these  kinds  of  pavements  are  suitable  for 
such  a  city  as  New- York. 

A  great  number  of  different  kinds  of 
pavements  have  been  tried  in  New-York 
city.  The  cobble  stone  or  small  boulder 
pavement,  is  the  oldest,  and  not  a  bad 
pavement  when  well  laid  down,  but  this 
is  seldom  the  case,  and  one  great  difficulty 
in  the  way  of  its  endurance,  is  the  great 
variety  in  the  quality  of  the  stones. 
Wooden  blocks  were  at  one  time  suppos- 
ed to  be  the  best  of  all  pavements,  before 
their  enduring  qualities  were  tried.  The 
pavement  which  has  got  the  name  of 
"  Russ"  in  this  city,  is  nothing  more  nor 
less  than  the  Neapolitan  pavement,  only 
its  pozzoloni  bed  of  concrete,  for  the 
diagonal  blocks,  is  made  in  sections.  It 
will  soon  have  to  be  treated  in  this  city, 
after  it  becomes  smooth,  like  the  pave- 
ment in  Naples.  This  is  the  only  objec- 
tion to  it,   but%  a  very  serious  one. 


pea] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


43*7 


Pavement  with  rough  tops  is  best  for  steep 
inclines,  to  allow  horses  to  pull  heavy 
loads  up  the  same,  and  although  not  re- 
quired in  such  a  city  as  New-York,  it  may 
he  good  for  some  other  city.  The  Perrine 
pavement  is  not  suitable  for  streets  like 
Broadway,  where  the  carriages  and  omni- 
busses  will  be  continually  crossing  the 
tracks,  and  it  will  be  expensive  for  re- 
pairs, because  there  is  so  much  street  lift- 
ing for  gas  pipes  and  common  sewers. 
The  Rus«  and  Perrine  pavements  are 
solid  and  lasting,  but  we  must  look  to  a 
pavement  that  will  be  enduring,  easily 
repaired,  easily  laid  down,  and  that  will 
obviate  the  surface  difficulties  of  the  two 
pavements  mentioned. 

A  new  system  has  been  tried  in  Lon- 
don, and  has  been  tested  for  ten  years 
with  the  most  gratifying  results.  This 
method  is  to  remove  the  subsoil  to  the 
depth  of  sixteen  inches,  then  lay  a  layer 
of  4  inches  of  strong  gravel,  well  rammed 
down,  then  another  layer  of  gravel,  and 
a  little  chalk  is  well  rammed,  and  a  third 
of  the  same  stuff,  all  well  rammed,  and 
the  street  made  slightly  rounding.  Stones 
of  good  granite  four  inches  deep,  three 
inches  thick,  and  four  inches  long,  are 
then  laid  down  in  fine  sand,  each  care- 
fully placed  not  to  rock  in  its  bed,  and 
the  whole  surface  well  rammed  down. 
This  system  has  been  found,  by  thorough 
experience,  to  be  infinitely  preferable  to 
the  large  blocks,  and  for  that  reason  it  is 
well  worthy  of  the  attention  of  our  city 
authorities. 

PEARL  ASH.  The  common  name  for 
carbonate  of  potash. 

PEARL  BARLEY,  is  common  barley 
deprived  of  its  husk  and  rounded,  and 
polished  in  a  mill. 

PEARL  POWDER  is  a  watery  precipi- 
tate of  the  nitric  solution  of  bismuth,  with 
the  addition  of  muriatic  acid.  Sulphur- 
etted hydrogen,  or  coal  gas,  turns  it 
black. — Or,  with  fine  powder  of  French 
chalk  mix  an  equal  weight  of  magistery 
of  bismuth. 

PEARLS.  These  are  substances  form- 
ed by  certain  bivalve  mollusks,  consisting 
of  concentric  layers  of  a  fine  compact  na- 
cre, or  substance  identical  with  that  which 
lines  the  inside  of  the  shell;  they  are 
sometimes  found  free  and  detached  with- 
in the  lobes  of  the  mantle,  but  most  com- 
monly adherent  to  the  nacrous  coat  of 
the  shell,  which  on  that  account  is  termed 
"  mother  of  pearl."  The  species  of  bi- 
valve which  produces  the  most  valuable 
pearls  is  the  pearl  oyster  of  Ceylon,  Me- 
leagrina   margaritifera,    Lam.    A    pure 


piece  is  generally  spherical,  and  has  a 
white,  or  oluish,  or  yellowish  white  color, 
with  a  peculiar  lustre  and  irridescence, 
and  consists  of  alternating  concentric 
layers  of  membrane  and  carbonate  of 
lime.  When  steeped  in  dilute  muriatic 
acid,  the  carbonate  is  decomposed  with 
effervescence,  and  films  of  membrane  re- 
main undissolved. 

Pearls  were  in  the  highest  possible  es- 
timation in  ancient  Rome,  and  bore  an 
enormous  price.  Their  cost  in  modern 
times  has  very  much  declined ;  partly, 
no  doubt,  from  changes  of  manners  and 
fashions,  but  more,  probably,  from  the 
admirable  imitations  of  pearls  that  may 
be  obtained  at  a  very  low  price.  Accord- 
ing to  Mr.  Milburn,  a  handsome  necklace 
of  Ceylon  pearls,  smaller  than  a  large  pea, 
cost  from  $850  to  $1,500,  but  one  of  pearls 
about  the  size  of  peppercorns  may  be  had 
for  $75 ;  the  pearls  in  the  former  sell  at  5 \ 
dollars  each,  and  those  in  the  latter  at 
about  37  i  cents.  When  the  pearls  dwin- 
dle to  the  size  of  a  small  shot,  they 
are  denominated  seed  pearls,  and  are  of 
little  value.  They  are  mostly  sent  to 
China.  One  of  "the  most  remarkable 
pearls  of  which  we  have  any  authentic 
account  was  bought  by  Tavernier,  at  Cat- 
ifa,  in  Arabia,  a  fishery  famous  in  the 
days  of  Pliny,  for  the  enormous  sum  of 
$50,000 !  It  is  pear-shaped,  regular,  and 
without  blemish.  The  diameter  is  '63 
inch  at  the  largest  part,  and  the  length 
from  2  to  3  inches.  It  is  in  the  pos- 
session of  the  shah  of  Persia. 

The  pearl  oyster  is  fished  in  various 
parts  of  the  world,  particularly  on  the 
west  coast  of  Ceylon ;  at  Tuticorin,  in 
the  province  of  Tinnevelly,  on  the  coast 
of  Coromandel ;  at  the  Bahrein  Islands, 
in  the  Gulf  of  Persia;  at  the  Sooloo  Isl- 
ands ;  off  the  coast  of  Algiers ;  off  St. 
Margarita,  or  Pearl  Islands,  in  the  West 
Indies,  and  other  places  on  the  coast  of 
Colombia;  and  in  the  Bay  of  Panama,  in 
the  South  Sea.  Pearls  have  sometimes 
been  found  on  the  Scotch  coast,  and  in 
various  other  places. 

The  pearl  fishery  of  Tuticorin  is  mon- 
opolized by  the  East  India  Company,  and 
that  of  Ceylon  by  Royalty.  But  these 
monopolies  are  of  no  value,  as  in  neither 
case  does  the  sum  for  which  the  fishery  is 
let  equal  the  expenses  incurred  in  guard- 
ing, surveying,  and  managing  the  banks. 
It  is  therefore  sufficiently  obvious  that 
this  system  ought  to  be  abolished,  and 
every  one  allowed  to  fish  on  paying  a 
moderate  licence  duty.  The  fear  of  ex- 
hausting the  banks  is  quite  ludicrous. 


438 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[pea 


The  fishery  would  be  abandoned  as  un- 
profitable long  before  the  breed  of  oysters 
had  been  injuriously  diminished,  and  in 
a  few  years  it  would  be  as  productive  as 
ever.  Besides  giving  fresh  life  to  the 
fishery,  the  abolition  of  the  monopoly 
would  put  an  end  to  some  very  oppressive 
regulations  enacted  by  the  Dutch  more 
than  a  century  ago. 

PEARLS,  ARTIFICIAL.  These  are 
small  globules  or  pear-shaped  spheroid? 
of  thin  glass,  perforated  with  two  oppo- 
site holes,  through  which  they  are  strung, 
and  mounted  into  necklaces,  &c,  like  real 
pearl  ornaments.  They  must  not  only 
be  white  and  brilliant,  but  exhibit  the  ir- 
ridescent  reflections  of  mother  of  pearl. 
The  liquor  employed  to  imitate  the 
pearly  lustre,  is  called  the  essence  of  the 
East  (essence  (Porient),  which  is  prepared 
by  throwing  into  water  of  ammonia  the 
brilliant  scales,  or  rather  the  lamelke,  se- 
parated by  washing  and  friction,  of  the 
scales  of  a  small  river  fish,  the  blay,  called 
in  French  ablette.  These  scales  digested 
in  ammonia,  having  acquired  a  degree  of 
softness  and  flexibility  which  allow  of 
their  application  to  the  inner  surfaces  of 
the  glass  globules,  they  are  introduced  by 
suction  of  the  liquor  containing  them  in 
suspension.  The  ammonia  is  volatilized 
in  the  act  of  drying  the  globules. 

Some  manufacturers  employ  ammonia 
merely  to  prevent  the  alteration  of  the 
scales';  that  when  they  wish  to  make  use 
of  them  they  suspend  them  in  a  well 
clarified  solution  of  isinglass,  then  pour  a 
a  drop  of  the  mixture  into  each  bead, 
and  spread  it  round  the  inner  surface. 
It  is  doubtful  whether,  by  this  method, 
the  same  lustre  and  play  of  colors  can  be 
obtained  as  by  the  former.  It  seems, 
moreover,  to  be  of  importance  for  the  suc- 
cess of  the  imitation,  that  the  globules  be 
formed  of  a  bluish,  opalescent,  very  thin 
glass,  containing  but  little  potash  and  ox- 
ide of  lead.  In  every  manufactory  of  ar- 
tificial pearls,  there  must  be  some  work- 
men possessed  of  great  experience  and 
dexterity.  The  French  excel  in  this  in- 
genious branch  of  industry. 

PEARL  WHITE  is  a  submuriate  of 
bismuth,  obtained  by  pouring  a  solution 
of  the  nitrate  of  that  metal  into  a  dilute 
solution  of  sea  salt,  whereby  a  light  and 
very  white  powder  is  obtained,  which  is 
to  be  well  washed  and  dried.  See  Bis- 
muth. 

PEARLSINTER.  In  mineralogy,  a 
Bilicious  mineral  found  in  volcanic  tufa : 
it  is  also  called  fiorite. 

PEARLSTONE.  A  variety  of  obsidian, 


a  volcanic  product  of  a  pearly  lustre :  it 
is  a  silicate  of  alumina. 

PEASTONE,  or  PISOLITE.  A  vari- 
ety of  limestone  composed  of  globular 
concretions  the  size  of  a  pea. 

PEAT.  The  natural  accumulation  of 
vegetable  matter  on  the  surface  of  lands 
not  in  a  state  of  cultivation ;  always  more 
or  less  saturated  with  water,  and  generally 
abounding  in  modifications  of  extractive 
matter,  varying  with  the  nature  of  the 
plants  of  which  the  peat  is  composed. 

Peat  is  generally  of  a  black  or  dark 
brown  color,  or,  when  recently  formed, 
of  a  yellowish  brown  :  it  is  soft,  and  of  a 
viscid  consistence ;  but  it  becomes  hard 
and  darker  by  exposure  to  the  air.  It  is 
generally  more  or  less  mixed  with  earthy 
substances.  When  steeped  in  water  it 
gives  out  a  brown  liquor,  more  or  less 
dark.  When  thoroughly  dried  it  may 
be  set  fire  to,  and  burns  slowly,  giving 
out  a  gentle  heat  without  much  smoke. 
This  smoke  communicates  a  peculiar  fla- 
vor to  all  the  articles  with  which  it  comes 
in  contact ;  and  this  flavor  is  considered 
a  characteristic  of  spirits  which  have  been 
distilled  in  vessels  heated  by  this  kind  of 
fuel,  and  also  of  malt,  corn,  and  fish  which 
have  been  dried  by  it.  Peat  abounds  in 
every  part  of  the  world,  but  more  espe- 
cially in  the  cold  moist  climates  of  tem- 
perate regions,  and  generally  in  those 
parts  of  Europe  where  the  ground  is 
moist  without  natural  drainage,  and 
where  the  sun's  light  is  obscured  by 
clouds.  It  covers  many  thousand  acres 
in  Ireland,  and  in  the  Highlands  and 
western  counties  of  the  Lowlands  of  Scot- 
land, and  in  the  western  counties  of  En- 
gland ;  but  all  these  bogs  are  rapidly  dis- 
appearing, in  consequence  of  being 
drained,  and  having  their  surfaces  slight- 
ly covered  with  earth,  and  stirred  and 
sown  with  grass  seeds. 

When  peaty  matter  accumulates  on  the 
sides  of  acclivities  it  is  generally  compar- 
atively dry,  and  is  then  called  hill-peat; 
but  when  peat  accumulates  on  hollow 
places,  or  on  flat  surfaces,  it  is  generally 
thoroughly  saturated  with  water,  and  is 
then  called  peat-bog.  In  most  cases  the 
principal  plant  which  forms  the  peatty 
matter  is  the  Sphagnum  palustre  ot  Lin- 
naeus ;  a  moss  which  is  common  on  all 
moist  peaty  surfaces  throughout  Europe, 
and  is  frequent  in  many  parts  of  North 
America.  This  moss  continues  growing 
upwards  from  the  points  of  the  shoots, 
wnile  decay  is  advancing  in  a  similar 
manner  from  their  lower  extremities; 
thus  forming  a  thick,  close  mass  of  vege- 


'] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


439 


table  matter,  which  rots  below  as  it  in- 
creases in  height.  The  rotten  part  is  fre- 
quently dug  out  and  dried,  to  be  used  as 
fuel,  or  to  be  mixed  with  dung  or  lime 
and  rotted  into  manure. 

When  peaty  matter  accumulates  on  a 
surface  which  abounds  in  springs,  the 
water  sometimes  oozes  out  beneath  the 
peat,  and  between  it  and  the  natural  soil, 
in  such  quantities  as  to  raise  up  the  layer 
of  peat,  and  float  it  off  to  a  distance ; 
sometimes  carrying  every  thing  before  it, 
and  ending  by  burying  under  it  lands  in 
a  state  of  culture.  About  the  middle  of 
the  18th  century,  a  remarkable  irruption 
of  this  kind  took  place  near  Annan  in 
Dumfries-shire  ;  and  such  irruptions  are 
frequent  in  Ireland.  The  circumstances 
favorable  to  the  growth  of  peat  are  a  soil 
abounding  in  springs,  a  flat  surface  or 
hollow  surrounded  by  hills,  and  a  moist 
climate.  Hence  peat-bogs  are  more  abun- 
dant in  Ireland,  and  in  the  western  coun- 
ties of  Scotland,  than  in  any  other  part  of 
the  British  empire. 

When  an  accumulation  of  peat  has 
taken  place  in  a  level  situation,  or  on  an 
acclivity  not  abounding  in  springs,  the 
matter  accumulated  is  comparatively  dry, 
and  is  then  called  peat  moss.  One  of 
the  most  remarkable  peat  mosses  in  Brit- 
ain is  the  Flanders  Moss,  in  Stirlingshire. 
It  rests  on  a  flat  surface  of  excellent  allu- 
vial soil,  of  which  it  covers  about  4000 
acres.  Great  part  of  this  peat  moss,  being 
quite  light,  has  been  cut  into  small 
pieces,  and  floated  off,  by  means  of  a 
stream  of  water,  to  the  sea;  thus  expos- 
ing the  natural  soil,  and  rendering  it  fit 
for  culture.  This  operation  was  com- 
menced at  Blair-Drummond,  towards  the 
end  of  the  last  century,  by  the  celebrated 
Lord  Kaimes,  and  is  still  continued  by  his 
son,  Mr.  Drummond. 

PEATS,  Turf.  Peat  bog  cut  out  in 
small  square  or  rectangular  pieces,  and 
dried  for  being  used  as  fuel.  These 
pieces  are  cut  out  with  light  spades  in  the 
summer  season,  spread  abroad  to  dry, 
and  afterwards  carted  home  and  put  up  in 
stacks  or  heaps,  which  are  thatched  to 
exclude  the  rain.  These  peats  are  after- 
wards used  as  fuel,  not  only  for  domestic 
Surposes,  but  for  burning  lime,  and  for 
eating  kilns  for  drying  corn,  &c.  To 
facilitate  the  drying  of  peat  the  water  is 
sometimes  pressed  out  of  the  square 
pieces  after  they  are  cut,  and  thrown  out 
of  the  bog,  by  a  compressing  machine, 
which  also  renders  the  material  more 
compact  and  durable  in  the  fire.  Peats 
are  also  sometimes  charred  by  a  smoth- 


ered combustion,  so  as  to  be  rendered 
better  adapted  to  serve  as  a  substitute  for 
pit-coal,  coke,  or  charcoal,  in  smelting 
iron  or  other  metals,  in  generating  steam, 
&c.  Attempts  have  been  made  to  sep- 
arate astringent  matter  from  peat,  and  to 
use  it  in  tanning  leather. 

PEAT  SOIL.  Peat  in  a  state  of  de- 
composition, on  which  corn  or  other  ag- 
ricultural crops  may  be  grown.  The  pro- 
cess of  turning  living  peat  into  peat  soil 
is  greatly  facilitated  by  draining,  and  by 
laying  earth  or  lime  on  its  surface,  and  af- 
terwards mixing  the  earthy  matter  with 
the  peaty  by  ploughing  or  digging.  In 
this  manner  every  kind  of  peaty  surface 
may  be  rendered  available  for  agricultural 
purposes;  and  accordingly,  in  Ireland, 
good  crops  of  corn,  potatoes,  and  artificial 
grasses  are  produced  on  the  surface  of  peat 
lands,  which  consist  of  a  layer  of  neat  from 
five  to  twenty  feet  in  depth.  The  plants 
which  thrive  best  on  the  surface  of  beds 
of  peat  of  this  description  are  those  which 
extend  their  roots  immediately  uuder  the 
surface.  Hence  few  trees  will  thrive  in 
such  soils,  with  the  exception  of  the 
spruce  fir,  the  silver  fir,  the  birch,  and 
two  or  three  kinds  of  willows.  Peaty 
soil  is  extensively  used  in  gardening,  in 
the  culture  of  plants  which  are  found 
growing  on  this  soil  in  a  wild  state. 

Peat  is  not  extensively  found  in  the 
United  States.  The  light  soil  and  the  ex- 
tensive clearings  in  New-England  have 
prevented  accumulations  of  vegetable 
matter.  Peat  is  common  in  Maine  and 
the  Canadian  border,  and  many  of  the 
swamp  mucks  of  New-York,  New-Jersey, 
and  Pennsylvania,  contain  as  much  peaty 
matter  as  the  bogs  of  Ireland,  and  might 
be  cut  and  dried  for  fuel. 

Charred  peat  is  among  the  best  of 
deodorizers,  from  the  absorbent  property 
of  the  finely-divided  charcoal,  hence  its 
value  when  added  to  night-soil  to  make 
compost  manure.  Some  time  since  a 
company  was  started  in  Ireland  to  manu- 
facture out  of  peat  and  turf,  naphtha,  par- 
afine,  volatile  oil,  and  salts  of  ammonia, 
with  considerable  profit.  Small  quanti- 
ties of  these  substances  are  obtained  by 
the  close  distillation  of  peat,  but  not  the 
profitable  return  calculated  on  by  over- 
drawn estimates.  The  charcoal  of  peat  is 
that  best  adapted  for  the  mauufacture  of 
gunpowder. 

Peat  from  wood,  or woody peat,  is  a  com- 
position  of  the  branches,    trunks,   and 
roots  of  trees,  with  their  leaves,  and  the 
shrubs  and  plants  which  have  grown  up 
,  among  them,  which  have  lain  so  long  in 


440 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


L' 


water  as  to  have  decayed  into  a  mass  soft 
enough  to  be  cut  with  a  spade.  The  co- 
lor is  a  blackish  brown,  like  that  of  mossy 
peat ;  and  it  may  be  used  as  manure,  for 
fuel,  and  for  the  growth  of  plants.  It  is 
abundant  in  North  America,  where  it 
forms  the  soil  in  which  many  of  the  plants 
and  trees  of  that  country  thrive  with  the 
greatest  vigor.  Wherever  it  can  be  found 
it  is  the  most  suitable  of  all  kinds  of  peat 
for  garden  purposes.  This  kind  of  peat 
is  frequently  burned  for  its  ashes ;  and 
these,  from  the  alkali  they  contain,  are 
found  an  excellent  manure. 

Peat,  sandy,  or  sandy  peat,  is  mossy 
peat  in  a  state  of  decay  or  mould,  natur- 
ally mixed  with  sand  brought  over  it, 
from  soil  lying  above  its  level,  or  by  the 
overflowings  of  rivers.  It  is  used  in  gar- 
dening for  the  same  purposes  as  heath 
soil. 

PECTIC  ACID  is  the  acid  of  jellies. 
Take  any  quantity  of  carrots ;  wash  and 
cleanse  them  well,  then,  by  means  of  a 
rasp,  reduce  them  to  a  pulp  ;  express  this 
strongly,  and  wash  the  marc  with  distil- 
led or  filtered  rain-water  until  it  cease, 
by  expression,  to  be  colored.  Mix  fifty 
parts  of  the  washed  marc,  expressed,  with 
300  parts  of  distilled  water,  and  1  part  of 
a  solution  of  caustic  potash  ;  then  heat 
the  mixture  till  it  boil,  and  let  it  boil  for 
a  quarter  of  an  hour,  or  until  a  portion  of 
the  fluid  coagulate  completely  into  a  jelly 
with  an  acid.  Pass,  now,  the  boiling 
liquor  through  a  cloth,  and  wash  the  mass 
with  distilled  or  filtered  rain-water,  mix- 
ing these  washings,  passed  through  the 
cloth,  with  that  which  was  strained  while 
hot.  The  mixed  fluid  should  become 
thick  and  gelatinous  on  cooling.  This 
contains  a  pectate  of  potash,  which  may 
be  decomposed  by  a  small  quantity  of 
muriate  of  lime,  largely  diluted  with  dis- 
tilled water,  by  which  means  an  insoluble 
gelatinized  pectate  of  lime  is  formed, 
which  should  be  well  washed  on  a  cloth. 
The  washed  pectate  is  next  to  be  boiled, 
for  a  few  minutes,  with  distilled  water, 
acidulated  with  muriatic  acid,  to  dissolve 
the  lime  and  the  starch  ;  and,  by  throw- 
ing: the  whole  on  a  cloth,  and  washing  it 
with  distilled  water,  the  pectic  acid  is  pro- 
cured. 

PEDOMETER.  An  instrument  in  the 
shape  of  a  small  watch  which  enables  a 

5>erson  to  tell  over  what  space  of  ground 
le  has  walked  or  ridden.  It  is  so  con- 
structed that  when  the  body  of  the  tra- 
veller is  raised  either  by  the  spring  of  his 
foot  or  the  motion  of  his  horse,  a  lever  is 
made  to  act  upon  the  wheel  work  of  the 


instrument,  and  an  index  or  hand  on  tho 
dial  plate  points  to  the  figures  which  in- 
dicate the  number  of  miles  passed  over. 

PELTRY  is  nearly  synonymous  with 
fur,  and  comprehends  the  skins  of  differ- 
ent kinds  of  wild  animals  that  are  found 
in  high  northern  latitudes,  both  of  this 
and  the  European  continent ;  such  as  the 
beaver,  bear,  moosedeer,  marten,  mink, 
sable,  wolverine,  wolf,  &c.  "When  these 
skins  have  received  no  preparation  It.t 
from  the  hunters,  they  are  most  properly 
called  peltry ;  but  when  they  have  had 
the  inner  side  tawed  or  tanned  by  an 
aluminous  process,  they  may  then  be  de- 
nominated furs. 

The  scouring  or  cleaning  of  peltry  is 
performed  in  a  large  cask,  or  truncated 
cone  laid  on  its  side,  and  traversed  by  a 
revolving  shaft,  which  is  furnished  with 
a  few  rectangular  rounded  pegs.  These 
are  intended  to  stir  round  the  skins, 
while  they  are  dusted  over  with  Paris 
planter,  whitening,  or  sometimes  sand, 
made  as  hot  as  the  hand  can  bear.  The 
bottom  of  the  cask  should  be  grated,  to  al- 
low the  impurities  to  fall  out.  The  lust- 
rage,  which  the  cleansed  skins  next  un- 
dergo, is  merely  a  species  of  dyeing, 
either  topical,  to  modify  certain  disagre- 
able  shades,  or  general,  to  impart  a  more 
beautiful  color  to  the  fur. 

PENCILS,  Black  Lead,  Manufacture 
of.  The  best  pencils  of  this  kind  are 
made  from  a  natural  ore,  plumbago,  but 
there  are  other  kinds  made  of  plumbago- 
dust  and  antimony.  The  lumps  of  pure 
plumbago,  when  scraped  from  dirt,  are 
generally  of  an  irregular  form,  not  of  a 
large  size.  These  lumps  are  cut  into  thin 
slices  by  a  circular  saw,  each  slice  being 
sawn  by  a  gauge  to  its  proper  thickness. 
The  saw  runs  vertically  and  the  plum- 
bago is  fed  below  it,  the  workmen  gradu- 
ally raising  it,  until  the  slice  is  cut  off, 
where  it  falls  down  slice  upon  slice  of 
different  sizes,  upon  a  table  below.  One 
edge  is  then  made  straight  with  a  shav- 
ing tool,  and  it  is  then  fit  to  be  inserted 
into  the  wood.  The  wood  is  cedar,  in 
half  squares  cut  by  a  circular  saw  into  the 
lengths  of  the  pencil.  A  groove  is  cut  by 
a  proper  gauge  plane  into  one  side  of  the 
wood  square,  and  the  workman  takes  a 
piece  of  the  cut  plumbago,  with  its  edge 
made  straight,  and  dips  it  into  strong 
glue  and  then  inserts  it  into  the  groove, 
and  then  with  a  very  sharp  instrument 
makes  a  slight  cut  at  each  end  and  gives 
the  plumbago  a  slight  snap,  when  it 
breaks  off  with  a  clean  straight  edge. 
This  is  again  dipped  in  the  glue  and  ope- 


pen] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


441 


rated  like  the  other  piece,  until  the  whole 
slice  is  used  up  or  the  pencil  groove  filled, 
when  the  whole  surface  is  smoothed 
along  and  the  two  pieces  are  firmly  glued 
together,  forming  a  rough  square  pencil. 

To  make  it  round,  it  is  first  forced 
through  a  square  hole  in  a  steel  puppet, 
by  the  workman ;  and  on  the  other  side 
of  this  puppet,  there  is  a  small  planing 
tool  revolving  on  a  centre,  with  two 
gauges  on  it,  to  turn  it  round  and  to  the 
exact  size.  As  soon  as  the  end  of  the 
pencil  projects  from  the  finishing  gauge 
of  the  cutters,  it  is  forced  into  a  circular 
hole  in  a  steel  plate,  through  which  it  is 
drawn  with  a  pair  of  wooden  nippers, 
and  it  comes  out  beautifully  round  pol- 
ished. It  is  polished  by  the  outer  end  of 
the  circular  hole  being  smaller  than  the 
the  inner,  which  thus  compresses  and 
polishes  the  wood. 

Ever-Pointed  Lead.  The  round  pieces 
of  lead  for  pencil  cases  are  first  sawed  in- 
to small  square  pieces,  and  they  are  then 
made  round  by  forcing  them  lengthways 
through  three  circular  holes  of  different 
sizes  cut  in  pieces  of  ruby.  In  passing 
through  the  first  hole,  only  the  four  an- 
gles of  the  prism  are  cut  off,  and  it  is 
then  octagonal;  the  next  hole  is  smaller, 
and  it  takes  ofr  these  eight  angles  and  it 
then  becomes  a  prism  of  sixteen  sides ; 
and  in  the  next  passage  through  the  small 
hole,  it  is  made  perfectly  round.  The 
plumbago  is  fed  into  the  ruby  by  being 
laid  on  a  groove  in  a  piece  of  metal,  with 
a  steel  pin  to  keep  the  plumbago  from  be- 
ing pressed  back. 

The  pure  Cumberland  black-lead  (plum- 
bago) is  of  too  soft  and  yielding  a  nature 
to  enable  an  artist  to  make  a  fine  clear 
line;  to  produce,  therefore,  a  pencil  that 
will  effect  this,  a  hard  resinous  matter  is 
intimately  combined  with  the  lead  in  the 
following  way  : — Fine  Cumberland  lead 
(in  powder)  and  shellac  are  first  melted 
together  by  a  gentle  heat ;  this  compound 
is  then  reduced  to  powder  again,  then  re- 
melted,  then  powdered  again,  and  re- 
meited  until  both  substances  are  perfectly 
incorporated,  and  it  has  acquired  a  per- 
fectly uniform  consistence.  The  mass  is 
then  sawed  into  slips,  and  glued  into  the 
cedar  mountings,  in  the  usual  manner  of 
making  other  black-lead  pencils.  To 
render  thein  of  various  degrees  of  hard- 
ness, the  materials  are  differently  pro- 
portioned ;  the  hardest  having  the  most 
shellac,  the  softer  but  very  little,  and  the 
softest  none ;  and  their  blackness  is  in- 
creased in  proportion  to  their  softness. 

PENDANT.  In  Gothic  architecture, 
19* 


an  ornamented  polygonal  piece  of  stone 
or  timber  hanging  down  from  the  vault 
or  roof  of  a  building.  Of  stone  pendants 
some  exquisite  examples  may  be  seen  in 
Henry  VIII.'s  Chapel  at  Westminster. 
In  ancient  writers  the  springers  of  arches, 
which  rest  on  shafts  or  corbels,  are  called 


Pendants  of  a  Ship  are  those  streamers 
or  long  colors  which  are  split  or  divided 
into  two  parts  ending  in  points,  and  hang 
at  the  mast-head  or  at  the  yard-arm  ends. 

Pendant.  In  painting,  a  picture  or 
print  which,  from  uniformity  of  size  and 
subject,  seems  to  hang  up  as  a  companion 
to  another.  The  term  may  also  be  applied 
to  bassi  relievi  of  similar  sizes. 

Pendant  is  also  the  general  term  for  all 
kinds  of  ornaments  worn  in  the  ears  by 
both  sexes  in  savage,  and  by  females, 
chiefly,  in  civilized,  countries;  usually 
termed  ear-rings,  which  see. 

PENS.  Well  known  instruments  for 
writing,  usually  formed  of  the  quills  of 
the  goose,  swan,  or  some  other  bird. 
Metallic  pens  have  been  occasionally 
employed  for  a  lengthened  period;  but 
it  is  only  within  these  few  years  that  they 
have  been  extensively  introduced.  They 
first  began  to  be  largely  manufactured  by 
Mr.  Perry,  of  London.  Mr.  P.  having 
succeeded  in  giving  to  his  pens  a  greater 
degree  of  softness  and  elasticity  than  was 

}>ossessed  by  any  metallic  pens  previous- 
y  in  use,  they  speedily  obtained  a  very 
extensive  sale.  This  success  brought 
crowds  of  rivals  into  the  field;  so  that 
metallic  pens  are  now  manufactured  in 
vast  quantities. 

Pens,  Steel.  The  best  metal,  made 
from  Dannemora  or  hoop  (l)  iron,  is  se- 
lected, and  laminated  into  slips  about  3 
feet  long,  and  4  inches  broad,  of  a  thick- 
ness corresponding  to  the  desired  stiff- 
ness and  flexibility  of  the  pens.  These 
slips  are  subjected  to  the  action  of  a  stamp- 
ing-press, somewhat  similar  to  that  for 
making  buttons.  (See  Button,  and  Plat- 
ed Ware.)  The  point  destined  for  the 
nib  is  next  introduced  into  an  appropriate 
gauged  hole  of  a  little  machine,  and  press- 
ed into  the  semi-cylindrical  shape ;  where 
it  is  also  pierced  with  the  middle  slit, 
and  the  lateral  ones,  provided  the  latter 
are  to  be  given.  The  pens  are  now  clean- 
ed, by  being  tossed  about  among  each 
other,  in  a  tin  cylinder,  about  3  feet  long, 
and  9  inches  in  diameter ;  which  is  sus- 
pended at  each  end  upon  joints,  to  two 
cranks,  formed  one  on  each  of  two  shafts. 
The  cylinder,  by  the  rotation  of  a  fly- 
wheel, acting  upon  the  crank-shafts,  is 


442 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[pen 


made  to  describe  such  revolutions  as  agi- 
tate the  pens  in  all  directions,  and  polish 
them  by  mutual  attrition.  In  the  course 
of  4  hours  several  thousand  pens  may  be 
finished  upon  this  machine. 

Hardness  in  the  nib  being  the  desirable 
quality,  and  the  loss  of  time  mending 
quill  pens  being  seriously  felt,  substitutes 
have  been  generally  adoped.  Such  as 
silver  and  gold  pens,  tortoise-shell  bar- 
rels and  ruby  or  diamond  nibs  have  been 
made.  Pens  of  ruby,  set  in  fine  gold, 
have  been  said  to  last  6  years.  Some 
gold  pens  have  the  nibs  made  of  rhodium. 
Some  gold  pens,  on  examination  at  the 
Laboratory,  Cambridge,  Mass.,  have 
turned  out  to  be  sheet-iron,  galvanized 
and  plated.  The  iron  is  first  cut  out  with 
the  press,  thin  coated  with  zinc,  and  fi- 
nally with  gold. 

Fountain  pens  are  made  to  hold  a  reser- 
voir of  ink.  Music  pens  make  dots  as 
well  as  strokes.  The  geometric  pen  is 
an  ingenious  instrument  for  drawing 
curves. 

American  gold  pens.  Dr.  Spurgen,  to 
whom  the  public  is  already  indebted  for 
several  ingenious  inventions,  has  now 
patented  a  new  pen,  which  promises  to 
have  important  advantages  without  being 
in  any  degree  costly.  These  are  the  re- 
tention of  a  large  quantity  of  ink,  suffi- 
cient, for  example,  to  write  a  letter  with- 
out again  dipping  the  pen,  and  the  pre- 
vention of  corrosion.  Capilary  attraction 
and  galvanism  are  the  principles  involved, 
and  the  means  employed  are  very  simple. 
Within  a  common  iron  pen  a  small  plate 
of  zinc,  bent  to  follow  the  line  of  the  pen, 
is  secured  by  points  of  solder  at  a  short 
distance  from  the  former,  by  means  of 
which  the  ink  is  securely  retained,  and  a 
galvanic  current  is  kept  up.  The  pro- 
gress of  the  manufacture  of  gold  pens  in 
America  will  serve  to  show  the  extent  of 
business  which  may  be  done  in  an  article 
of  this  kind,  when  successful. 

The  Charleston  Courier  (U.  S.)  says, 
the  first  gold  pen  was  made  in  New- York 
in  1838,  and  now  the  principal  manufac- 
turer of  them  employs  a  capital  of  80,000 
dollars  in  the  undertaking.  In  the  man- 
ufacture of  pens  the  gold  is  first  rolled  out 
in  ribbons,  and  then  cut  with  a  die  to  the 
proper  shape,  the  points  put  on  and  then 
ground  down  to  the  required  nib.  The 
points  are  of  iridium,  a  new  metal  found 
with,  platinum.  The  points  are  all  im- 
ported, generally  without  the  ceremony 
of  an  introduction  to  the  Custom  House, 
and  cost  from  7  to  55  dollars  per  ounce. 


The  pens  and  cases  sell  from  10  to  30 
dollars  per  dozen.  It  is  not  easy  to  make 
an  estimate  of  the  number  of  pens  manu- 
factured per  annum,  but  it  is  probably 
not  less  than  1,000,000,  of  which  one 
manufacturer,  Bagley,  makes  nearly  half. 
A  person  who  had  not  thought  of  the 
subject  would  scarcely  suppose  that  800 
lbs.  of  gold  were  used  up  every  year  in 
America,  in  the  manufacture  of  such  a 
trifling  article  as  pens — a  business  un- 
known ten  years  ago— yet  such  is  the  fact. 
A  statement  of  the  tons  of  iron  worked 
into  pens  in  England  every  year  would 
be  even  more  startling,  and  would  show 
that  Dr.  Spurgen's  improvement,  simple 
as  it  appears,  may,  if  it  fulfils  its  promises, 
be  more  productive  than  some  larger  mat- 
ters. 

PENDULUM.  If  any  heavy  body,  sus- 
pended by  an  inflexible  rod  from  a  fixed 
point,  be  drawn  aside  from  the  vertical 
position,  and  then  let  fall,  it  will  descend 
in  the  arc  of  a  circle  of  which  the  point 
of  suspension  is  the  centre.  On  reach- 
ing the  vertical  position  it  will  have  ac- 
quired a  velocity  equal  to  that  which  it 
would  have  acquired  by  falling  vertically 
through  the  versed  sine  of  the  arc  it  has 
described,  in  consequence  of  which  it 
will  continue  to  move  in  the  same  arc 
until  the  whole  velocity  is  destroyed; 
and,  if  no  other  force  than  gravity  acted, 
this  would  take  place  when  the  body 
reached  a  height  on  the  opposite  side  of 
the  vertical  equal  to  the  neight  from 
which  it  fell.  Having  reached  this  height 
it  would  again  descend,  and  so  continue 
to  vibrate  for  ever ;  but  in  consequence  of 
the  friction  of  the  axis,  and  the  resist- 
ance of  the  air.  each  successive  excursion 
will  be  diminished  and  the  body  soon  be 
brought  to  rest  in  the  vertical  position. 
A  body  thus  suspended,  and  caused  to 
vibrate,  is  called  a  pendulum;  and  the 
passage  from  the  greatest  distance  from 
the  vertical  on  the  one  side  to  the  great- 
est distance  on  the  other  is  called  an  os- 
cillation. 

In  order  to  investigate  the  circumstan- 
ces of  the  motion,  the  body  must  be  re- 
garded as  a  gravitating  point,  and  the  in- 
flexible rod  as  devoid  ot  weight.  This  is 
denominated  the  simple  pendulum,  and 
the  problem  to  be  resolved  is  to  deter- 
mine the  motion  of  a  point  constrained 
to  move  in  a  circular  arc  in  virtue  of  the 
accelerating  force  of  terrestrial  gravitv. 

According  to  the  theory  of  falling 
bodies  (see  Gravity,)  the  time  t  in  whicn 
a  hndy  fall*  through  the  space  s,  by  the 


pen] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


443 


the  accelerating  force  of  gravity,  is  given 

2 
by  the  equation  £  =  -v/— .  Let2«  =  £;thcn 

I  g 

t—y/-.    But  the  time  T,  of  the  oscilla- 

g 
tion  of  a  pendulum  whose  length  is  I,  is 

T  =  7T  v/  -  ;  therefore  T  :  t :  :  n :  1 ;  con- 
sequently the  time  of  the  oscillation  of  a 
pendulum  is  to  the  time  that  a  heavy  body 
would  fall  freely  by  the  force  of  gravity 
through  half  its  length,  as  the  circum- 
ference of  a  circle  to  its  diameter. 

If  we  suppose  that  the  time  to  be  ex- 
pressed in  seconds,  and  makeT=l,  we 
shall  have  g=iril.  Now,  Captain  Kater 
found  the  length  of  the  same  pendulum 
at  London  to  be  39-13929  inches,  and  we 
know  that  ^  ==  9-8696  ;  therefore  g  = 
9-8696  X  39-139  =  386-239  inches,  or  g  — 
32*2  feet.  It  follows,  therefore,  that  the 
space  through  which  a  body  falls  freely 
at  London  in  a  second  time  is  16*1  feet. 

Compound  Pendulum.  The  simple 
pendulum,  as  above  defined,  is  only  a 
theoretical  abstraction  ;  for  the  oscilla- 
ting body  can  neither  be  so  small  that  it 
may  be  regarded  as  a  mathematical  point, 
nor  can  the  rod  be  entirely  devoid  of 
weight.  "When  the  body  has  a  sensible 
magnitude,  and  the  suspending-rod  a 
sensible  magnitude  and  weight  as  they 
must  have  in  all  actual  constructions, 
the  apparatus  is  called  a  compound  pen- 
dulum ;  and  instead  of  being  supported 
by  a  single  point  it  is  supported  by  an 
axis,  or  by  a  series  of  points  situated  in 
the  same  straight  line.  According  to 
this  definition,  any  heavy  body  oscilla- 
ting about  an--axis  of  suspension  is  a 
compound  pendulum. 

In  every  compound  pendulum  there  is 
necessarily  a  certain  point  at  which  if  all 
the  matter  of  the  pendulum  were  collec- 
ted the  oscillations  would  be  performed  in 
exactly  the  same  time.  This  point  is  the 
centre  of  oscillation.  (See  Centre  of  Os- 
cillation.) It  is  situated  in  the  vertical 
plane  passing  through  the  centre  of  grav- 
ity of  the  pendulum,  and  at  a  distance 
from  the  axis  of  suspension  (the  axis 
being  always  supported  horizontal,) 
which  is  determined  by  the  following 
formula:  Let  d  m  be  the  element  of  the 
mass  of  the  compound  pendulum,  r  its 
distance  from  the  axis  ot  rotation,  and  x 
the  distance  of  the  centre  of  oscillation 
from  the  same  axis  ;  then 

jc=  /  r^dm-r-f  rdm; 


that  is,  the  distance  of  the  centre  of  os- 
cillation from  the  axis  of  suspension  is 
equal  to  the  moment  of  inertia  of  the  os- 
cillating body  divided  by  its  moment  of 
rotation.  This  value  of  x  is  the  length 
of  the  isochronous  simple  pendulum,  and 
is  what  is  always  to  be  understood  by  the 
term  length  of  a  pendulum. 

The  centre  of  oscillation  possesses  a 
very  remarkable  property,  which  was 
discovered  by  Huygens  ;  namely,  that  if 
the  body  be  suspended  from  this  point, 
or  a  horizontal  axis  passing  through  it 
parallel  to  the  former  axisot  suspension, 
its  oscillations  will  be  performed  in  the 
same  time  as  before  ;  in  other  words,  the 
axis  of  suspension  and  oscillation  are 
interchangeable.  This  property  furnish- 
es an  easy  practical  method  of  deter- 
mining the  centre  of  oscillation,  and 
thence  the  length  of  a  compound  pen- 
dulum. 

Applications  of  the  Pendulum. — The 
most  important  application  that  has  been 
made  of  the  pendulum  is  to  the  measure- 
ment of  time.  It  is  said  that  Galileo, 
while  a  young  man,  having  had  his  at- 
tention drawn  to  the  oscillation  of  a  lamp 
suspended  from  the  roof  of  a  church  in 
Pisa,  perceived  that,  although  their  ex- 
tent was  gradually  diminished,  they  con- 
tinued to  be  made  in  equal  times,  and 
thence  conceived  the  idea  of  employing  a 
pendulum  as  a  means  of  measuring  small 
intervals  of  time  in  astronomical  observa- 
tions. But  though  a  pendulous  body,  by 
the  isochronism  of  its  oscillations,  fur- 
nishes a  means  of  dividing  time  into 
equal  portions,  it  could  obviously  be  of 
no  great  use  until  a  method  was  devised 
of  continuing  the  motion,  and  register- 
ing the  number  of  oscillations.  The  ap- 
{)li"cation  of  clock-work  to  this  purpose 
nis  been  claimed  for  various  individuals, 
but  is  generally  and  deservedly  ascribed 
to  Huygens  ;  and  the  invention  one  of 
the  most  important  that  ever  was  made 
in  reference  to  practical  astronomy,  dates 
from  the  year  1656. 

Huygens1  researches  on  the  subject  of 
the  oscillations  of  the  pendulum  are  con- 
tained in  his  admirable  work  entitled 
Horologium  Ofcillatorium.  He  soon  found 
that  the  oscillations  in  circular  arcs  of 
different  amplitudes  are  not  equal,  the 
wider  requiring  rather  a  longer  time  than 
the  narrower  ;  and,  with  a  view  to  reme- 
dy this  defect,  he  undertook  to  investi- 
gate the  nature  of  the  curve  in  which  the 
oscillations  would  be  performed  in  equal 
times,  whatever  might  be  the  extent  of 
the  are  described.    The  curve  possessing 


4U 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


[pes 


this  remarkable  property  was  found  to  be 
the  cycloid. 

In  clocks  of  the  best  construction  tbe 
arc  of  vibration  is  very  small ;  and  the 
pendulum  is  made  very  heavy,  in  order 
that,  by  possessing  a  great  momentum, 
it  may  be  less  affected  by  the  imperfec- 
tions of  the  machinery. 

Compensation  Pendulum, — The  value  of 
the  pendulum  as  a  regulator  of  time- 
pieces depends  on  the  isochronism  of  its 
oscillations  ;  which,  in  its  turn,  depends 
on  the  invariability  of  the  distance  be- 
tween the  points  of  suspension  and  oscil- 
lation. But,  as  every  Known  substance 
expands  with  heat  and  contracts  with 
cold,  the  length  of  the  pendulum  will 
vary  with  every  alteration  of  tempera- 
ture, and  the  rate  of  the  clock  conse- 
quently undergo  a  corresponding  change. 
To  counteract  this  variation,  numerous 
contrivances  have  been  employed.  The 
principle  is,  however,  the  same  in  all  ; 
and  consists  in  combining  two  substan- 
ces, whose  rates  of  expansion  are  une- 
equal,  in  such  a  manner  that  the  ex- 
pansion of  the  one  counteracts  that  of 
the  other,  and  keeps  the  centre  of  oscil- 
lation of  the  compound  body  always  at 
the  same  distance  from  the  axis  of  sus- 
pension. A  brief  description  of  the  two 
compensation  pendulums  in  most  com- 
mon use — the  Mercurial  Pendulum  and 
the  Gridiron  Pendulum — will  sufficiently 
explain  the  means  by  which  compensa- 
tion is  obtained. 

Mercurial  Pendulum. — This  was  the 
invention  of  Mr.  George  Graham,  a  cele- 
brated watchmaker,  who  subjected  it  to 
the  test  of  experiment  in  the  year  1721. 
The  rod  of  the  pendulum  is  made  of 
steel,  and  may  be  either  a  flat  bar  or  a 
cylinder.  The  bob  or  weight  is  formed 
by  a  cylindrical  glass  vessel,  about  8 
inches  in  length  and  2  inches  in  diameter, 
which  is  filled  with  mercury  to  the  depth 
of  about  6i  inches.  The  cylinder  is  sup- 
ported and  embraced  by  a  stirrup,  formed 
also  of  steel,  through  the  the  top  of  which 
the  lower  extremity  of  the  rod  passes, 
and  to  which  it  is  firmly  fixed  by  a  nut 
and  screw  on  the  end  of  the  rod.  Now 
the  effect  of  an  increase  of  temperature 
on  this  apparatus  is  evidently  as  follows : 
In  the  first  place,  the  rod  expands,  and 
the  distance  between  the  axis  of  suspen- 
sion and  the  bottom  of  the  stirrup  is  in- 
creased. In  the  second  place,  by  the  ex- 
pansion of  the  mercury  in  the  cylinder, 
its  column  is  lengthened,  and  the  dis- 
tance of  its  centre  of  gravity  from  the 
bottom  of  the  stirrup  consequently  in- 


creased. But,  as  the  expansion  of  mer- 
cury is  about  sixteen  times  greater  than 
that  of  steel,  the  height  of  the  mercurial 
column  may  be  so  adjusted  by  trial  that 
the  expansion  of  the  rod  and  stirrup 
shall  be  exactly  compensated  by  that  of 
the  mercury,  and  the  centre  of  oscilla- 
tion of  the  whole  suffer  no  change.  This 
pendulum  is,  perhaps,  the  most  perfect 
of  all  compensators  ;  but,  as  its  adjust- 
ments are  attended  with  considerable  dif- 
ficulty, it  is  seldem  used  excepting  in  as- 
tronomical observatories. 

Gridiron,  Pendulum. — This 
was  contrived  by  Mr.  Harrison, 
the  inventor  of  the  chronome- 
ter. It  consists  of  a  frame  of 
nine  parallel  bars  of  steel  and 
brass,  arranged  and  connected 
as  in  the  annexed  figure.  The 
bars  marked  s  are  of  steel ;  the 
four  marked  b  are  of  brass  ; 
the  centre  rod,  of  steel,  is  fixed 
at  top  to  the  cross  bar  connect- 
ing the  two  middle  brass  rods, 
but  slides  freely  through  the 
two  lower  bars,  and  bears  the  fj 
bob  B.  The  remaining  rods  fM*iw* 
are  fastened  to  the  cross  pieces  at 
both  ends,  and  the  uppermost  cross 
piece  is  attached  to  the  axis  of  suspen- 
sion. It  is  as  easy  to  see,  from  the 
mere  inspection  of  the  figure,  that  the 
expansion  of  the  steel  rods  tends  to 
lengthen  the  pendulum,  while  that  of 
the  brass  rods  tends  to  shorten  it ;  conse- 
quently, if  the  two  expansions  exactly 
counteract  each  other,  the  length  of 
the  pendulum  will  remain  unchanged. 
The  relative  lengths  of  the  brass  and 
steel  bars  are  determined  by  the  ex- 
pansions of  the  two  metals,  which  are 
found  by  experiment  to  be,  in  general, 
nearly  as  100  to  61.  If,  then,  the  lengths 
of  all  the  five  steel  bars  added  together  be 
100  inches,  the  sum  of  the  lengths  of  the 
four  brass  bars  ought  to  be  61  inches. 
When  the  compensation  is  found  on  trial 
not  to  be  perfect,  an  adjustment  is  made 
by  shifting  one  or  more  of  the  cross  pie- 
ces higher  on  the  bars. 

Harrison's  pendulum  has  been  greatly 
improved  by  Troughton,  who  substituted 
for  the  two  parallel  brass  rods  two  cylin- 
ders of  brass,  sliding  the  one  within  the 
other,  to  which  the  steel  rods  are  at- 
tached. For  a  description  of  this,  and 
various  other  modes  of  compensation, 
we  refer  the  reader  to  an  excellent  chap- 
ter on  the  subject  by  the  late  Captain 
Kater,  in  the  volume  of  Mechanics  in  the 
Cabinet  Cyclopedia. 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


445 


Application  of  the  Pendulum  to  the  De- 
termination of  the  relative  Force  of  Gravi- 
ty at  different  Places. — There  are  two 
methods  of  determining  the  relative  in- 
tensity of  gravity  by  means  of  the  pen- 
dulum. According  to  the  first,  the  abso- 
lute length  of  the  simple  pendulum  j 
which  makes  a  certain  number  of  oscilla- 
tions in  a  given  time  is  accurately  ascer- 
tained at  each  of  the  places,  and  the  com- 
parative force  of  gravity  is  then  given  by 

the  formula  g'  =  —  g.    According  to  the 

other  method,  an  invariable  pendulum  is 
swung  at  the  different  places,  and  the 
number  of  its  oscillations  noted  at  each, 
when  the  relative  gravity  is  given  by  the 

N'2 
formula  g'  —  -ajojf,  Each  of  these  meth- 
ods have  been  followed  in  the  delicate 
experiments  which  have  been  made  for 
the  purpose  of  determining  the  figure  of 
the  earth  ;  but  though  the  results  of  both 
appear  to  be  nearly  equal  in  point  of  ac- 
curacy, the  latter  method,  on  account  of 
its  affording  greater  facilities  in  practice, 
is  now  generally  adopted. 

It  will  readily  be  conceived  that  a  pen- 
dulum would  bs  altogether  unfit  for  the 
purpose  of  determining  the  minute  va- 
riations of  gravity  if  it  were  attached  to 
a  clock,  or  any  machinery  by  which  its 
motions  could  be  influenced.  It  must 
be  suspended  from  a  very  firm  support, 
to  which  it  can  communicate  no  vibratory 
motion  ;  and  the  most  delicate  precau- 
tions are  necessary  to  avoid  the  effects  of 
friction,  and  other  disturbing  causes,  by 
which  the  experiment  may  be  influenced. 
The  method  followed  by  the  French  as- 
tronomers, in  their  operations  connected 
with  the  measurement  of  the  meridian, 
was  this  :  The  pendulum  was  composed 
of  a  sphere  of  platinum,  suspended  by  a 
slender  iron  wire  from  a  knife  edge  of 
hardened  steel  resting  on  plane  surfaces 
of  polished  agate.  It  was  placed  in  front 
of  a  well-regulated  astronomical  clock, 
with  which  its  oscillations  were  com- 
pared, and  the  distance  between  its  cen- 
tres of  suspension  and  oscillation  deter- 
mined by  calculation  from  the  length  of 
the  wire  and  the  diameter  of  the  sphere, 
ascertained  by  actual  measurement.  A 
different,  and  in  many  respects  preferable 
mode  of  measuring  the  lengths  of  the 
seconds'  pendulum,  was  adopted  by  Cap- 
tain Kater,  grounded  on  the  property  of 
oscillating  bodies  discovered  by  Huy- 
gens  ;  namely  that  the  centres  of  sus- 
pension and  oscillation  are  convertible. 


From  this  property  it  follows  that  if  two 
knife  edges,  turned  in  opposite  direc- 
tions, are  inserted  in  the  same  pendu- 
lum, and  the  mass  be  so  adjusted,  by 
means  of  a  movable  weight  sliding  on 
the  rod,  that  the  oscillations  are  per- 
formed in  exactly  equal  times  when  the 
pendulum  is  suspended  from  either  knife 
edge,  then  the  distance  between  the 
knife  edges  is  the  true  length  of  the  iso- 
chronous simple  pendulum.  In  this 
manner  the  measurement  is  effected 
more  directly,  and  no  calculation  is  re- 
quired for  finding  the  centre  of  oscilla- 
tion. A  third  method,  lately  put  in 
gractice  by  the  celebrated  astronomer 
■essel,  consists  in  suspending  a  ball  and 
wire  from  the  upper  end  and"  then  from 
the  lower  end  of  a  rod  of  a  given  length, 
the  ball  being  in  both  cases  at  the  same 
distance  below  the  rod.  From  the  dif- 
ference of  the  times  of  oscillation  of  the 
two  pendulums  thus  formed,  the  length 
of  the  simple  pendulum  can  be  compu- 
ted in  terms  of  the  rod,  which  is  the 
difference  of  their  lengths.  The  French 
method  is  described,  with  all  the  requi- 
site details,  in  the  third  volume  of  Base 
Metrique,  in  Delambre's  Astronvmie,  tome 
iii. ;  and  in  the  Becueil  d?  Observations 
Geodesiques,  &c,  by  Biot  and  Arago, 
Paris,  1821. 

Captain  Kater's  pendulum  was  formed 
of  a  very  thin  bar  of  plate  brass,  with  a 
heavy  bob  and  movable  weight, 
by  means  of  which  the  isochron-  jllA 
ism  was  obtained  when  the  sus- 
pension was  made  from  the  oppo- 
site knife  edges.  But  a  much 
simpler  modification  has  been 
adopted  in  the  recent  experi- 
ments. The  experimental  pendu- 
lums of  the  Eoyal  Astronomical 
Society  consist  merely  of  a  plain 
straight  bar  of  iron  or  copper,  2 
inches  wide,  half  an  inch  thick,  g 
and  about  62i  inches  long.  At  the 
distance  of  5  inches  from  one  end 
of  the  bar  is  placed  the  apex  of  one 
of  the  knife  edges,  A  ;  and  at  the 
distance  of  39-4  inches  therefrom  the 
apex  of  the  other  knife  edge,  B  ;  and 
the  required  adjustment  to  synchronism 
is  produced  by  filling  away  one  of  the 
ends  of  the  pendulum  until  the  vibra- 
tions are  found  by  trial  to  be  equal  in 
both  positions  of  the  pendulum.  It  is 
obvious  that,  for  the  purpose  of  merely 
ascertaining  the  variations  of  gravity,  a 
bar  of  this  form  with  a  single  knife  edge 
would  equally  answer  the  purpose  ;  but 
the  advantage  of  the  double  suspension 


446 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


is  this,  that  besides  having  two  distinct 
and  independent  pendulums,  each  of 
which  is  a  check  upon  the  other,  it  fur- 
nishes the  means  of  ascertaining  whether 
the  pendulum  has  sustained  any  acciden- 
tal injury,  which  would  be  immediately 
discoverable  from  the  inequality  of  the 
number  of  vibrations  between  the  two 
knife  edges. 

Corrections. — In  order  that  the  results 
of  different  sets  of  experiments  may  be 
exactly  comparable  with  each  other,  seve- 
ral corrections  must  be  applied.  The  first 
of  these  is  on  account  of  the  length  of  the 
arc  of  vibration,  which,  being  of  a  finite 
and  variable  extent,  the  duration  of  the  os- 
cillations is  consequently  unequal,  but 
always  greater  than  in  the  case  of  an 
infinitely  small  arc.  The  number  of  os- 
cillations is  reduced  to  the  case  of  an  in- 
finitely small  arc  by  the  formula. 


NX 


M  sin.  (A  +  a)  sin  (A  —  a) 
32  (log.  sin.  A — log.  sin.  a) 


where  N  is  the  number  observed,  M  the 
logarithmic  modulus  =  -4342945,  A  the 
initial,  and  a  the  final  arc  of  vibration  ; 
and  as  the  arcs  are  always  small,  the 
computation  may  be  shortened  by  using 
the  arcs  instead  of  sines. 

In  the  second  place,  all  the  experi- 
ments must  be  reduced  to  a  common 
standard  of  temperature,  which,  in  this 
country,  is  assumed  at  62°  of  Fahrenheit. 
Let  e  denote  the  rate  of  expansion  of  the 
metal,  t  the  mean  height  of  the  ther- 
mometer at  the  time  of  the  experiment ; 
then  the  correction  of  the  number  of  vi- 
brations on  account  of  the  temperature 
isNxie  (t— 62°.) 

A  third  correction  is  required  on  ac- 
count of  the  atmospheric  pressure.  The 
effect  of  the  pressure  of  the  atmosphere 
on  the  pendulum  is  to  diminish  the  force 
of  gravity  in  the  ratio  of  the  specific 
gravity  of  the  pendulum  to  that  of  the 
air  ;  and  on  this  principle  the  correction 
was  formerly  applied,  regard  being  had 
to  the  height  of  the  barometer.  But  it 
was  recently  remarked  by  Bessel  that  the 
pendulum  drags  with  it  a  certain  portion 
of  air,  the  amount  of  which  depends  on 
the  form  of  the  pendulum  ;  and,  conse- 
quently, the  specific  gravity  of  the  actu- 
ally moving  mass  cannot  be  previously 
computed,  but  must  be  ascertained  for 
each  pendulum  by  actual  experiments  in 
air  and  in  a  vacuum. 

PEPPER.  A  condiment  obtained 
from  the  piper  nigrum,  a  native  of  Mala- 
bar, where  it  is  cultivated  on  an  exten- 


sive scale.  It  is  a  climbing  plant,  and  ia 
supported  on  a  pole,  or  small  tree,  plant- 
ed for  this  purpose,  which  gives  to  the 
Eepper-grounds  an  appearance  similar  to 
op-fields.  The  pepper  of  Malacca,  Java, 
and  especially  of  Sumatra,  is  the  most 
esteemed.  Its  culture  has  been  intro- 
duced into  the  Isle  of  France,  and  thence 
into  Cayenne  and  the  West  Indies. 

White  pepper  is  nothing  more  than  the 
best  and  soundest  of  the  berries,  gather- 
ed when  fully  ripe,  and  deprived  of  their 
external  skin,  by  steeping  them  in  salt- 
water for  about  a  week,  at  the  end  of 
which  time  the  skins  burst ;  they  are 
then  dried  in  the  sun,  rubbed  between 
the  hands,  and  winnowed  to  separate  the 
hulls ;  it  is  much  less  pungent  than  the 
entire  berries.  The  leaves  of  the  P.  betel, 
a  native  of  the  same  parts  of  the  globe, 
serve  to  enclose  a  few  slices  of  the  areca- 
nut,  called  betel-nut,  and  a  little  shell 
lime,  which  substances  together  form  a 
masticatory  as  much  in  use  among  these 
nations  as  is  tobacco  in  Europe  and 
America. 

Black  Pepper  is  composed,  according  to 
M.  Pelletier,  of  the  vegetable  principle, 
piperine,  of  a  very  acrid  concrete  oil,  a 
volatile  balsamic  oil,  a  colored  gummy 
matter,  an  extractive  principle  analagous 
to  legumine,  malic  and  tartaric  acids, 
starch,  bassorine,  ligneous  matter,  with 
earthy  and  alkaline  salts  in  small  quanti- 
ty. Cubebs  pepper  has  nearly  the  same 
composition. 

PEPPERMINT  CORDIAL.  Into  1 
ounce  of  refined  sugar  drop  75  drops  of 
oil  of  peppermint,  and,  while  grinding 
with  the  sugar,  add  to  the  quantity  of  1 
pint  of  alcohol,  which  liquid  mix  with  10 
pints  of  alcohol,  and  10  gallons  of  water. 
Add  i  oz.  of  alum,  to  fine. 

Peppermint  Props.  Similarly  mix  and 
treat  2  lbs.  of  sugar  and  4  oz.  of  pepper- 
mint-water ;  and,  if  needful,  add  a  few 
drops  of  oil  of  peppermint. 

Peppermint  Lozenges.  In  mucilage  of 
gum  dragon,  flavored  with  oil  of  pepper- 
mint about  2  drs.  mix  2  lbs.  of  sugar  and 
2  oz.  of  starch. 

PERAMBULATOR  is  an  instrument 
for  measuring  distances  on  roads.  It  con- 
sits  principally  of  a  wheel,  upon  which  it 
runs,  and  an  index  which  shows  the  num- 
ber of  turns  of  the  wheel  reduced  into 
miles,  furlongs,  poles,  or  yards.  ^  The 
carriage  or  stock,  which  is  divided  in  or- 
der to  receive  the  wheel,  is  made  of 
wood,  and  is  about  three  feet  long.  At 
one  end  is  a  handle  for  the  person  who 
uses  it,  and  the  other  is  furnished  with 


PKB] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


447 


sockets,  in  which  the  axle  of  the  wheel 
turns.  Upon  the  stock,  and  just  in  front 
of  the  handle,  is  the  dial-plate,  with  its 
two  hands,  by  which  the  distance  is  re- 
gistered. The  wheel  is  8\  feet,  or  I  pole 
in  circumference ;  and  upon  one  end  of 
its  axis  is  a  small  pinion  which  works  in- 
to a  similar  pinion  at  the  end  of  a  rod 
passing  up  the  stock  or  carriage  to  the 
works  beneath  the  dial-plate.  Motion  is 
communicated  by  means  of  this  rod  to  a 
worm  or  micrometer  screw,  which  turns 
once  round  for  each  revolution  of  the  car- 
riage-wheel of  tlie  perambulator.  This 
worm  works  into  a  wheel  of  80  teeth, 
which  is  moved  forward  one  tooth  for 
every  i  pole,  and  carries  a  hand  or  index, 
which  makes  one  revolution  for  40  poles 
or  one  furlong.  On  the  axis  of  this  wheel 
is  a  pinion  of  8  teeth,  which  moves  a 
wheel  of  160  teeth.  This  last  wheel  car- 
ries another  hand,  which  makes  one  re- 
volution ftr  80  of  the  former,  that  is,  for 
ten  miles.  The  movements  of  the  two 
index  hands  thus  show  the  miles  and  fur- 
longs passed  over. 

Ihere  are  other  instruments  for  the 
same  or  similar  purposes,  bearing  differ- 
ent names,  as  Waywiser  and  Odometer, 
but  the  construction  of  all  of  them  is  very 
similar.  Waywiser  is  the  name  gener- 
ally given  to  that  form  of  the  instrument 
which  is  applied  to  a  carriage  in  which, 
by  a  slight  adaptation  to  one  of  the 
wheels  of  the  carriage,  the  instrument  is 
made  to  register  the  number  of  turns  of 
such  wheel  in  the  same  manner  as  the 
perambulator. 

PERCH.  The  main  timber  of  a  car- 
riage, which  extends  through  the  hind 
and  fore  spring  transom,  or  bars,  by 
which  the  principal  part  of  the  upper  car- 
riage is  supported.  The  hind  part  is  sup- 
ported and  united  to  it  by  hooping  two 
extending  timbers,  called  wings,  on  the 
side.  The  fore  part  is  fixed  to  the  perch 
by  a  strong  piece,  hooped  at  the  top,  and 
framed  through  the  fore  transom.  Some 
carriages  have  a  horizontal  wheel  in  the 
front,  the  same  as  the  crane-neck  carria- 
ges, and  these  have  no  hooping-piece  to 
the  perch,  but  are  secured  by  side- plates,  j 
Those  on  the  general  principle  have,  at 
the  bottom  in  tront,  a  flat  piece  called  a 
tongue,  which  goes  through  a  large  mor- 
tice in  the  fore  axle-tree  bed,  and  through 
which  the  perch-bolt  passes. 

Sometimes  the  perch  is  bent,  called  a 
compass  perch,  for  the  purpose  of  admit- 
ing  the  body  to  hang  tow,  or  to  form  a 
more  agreeable  line  to  the  shape.  When 
the  carriage  is  intended  for  a  whole  or 


horizontal  wheel,  the  perch  has  no  hoop- 
ing-piece, but  is  bolted  by  the  plates  at 
each  end  to  the  inside  of  the  transoms. 
Plating  the  sides  with  iron  is  a  great  im- 
provement, and  always  must  be  done  to 
perches  required  to  be  light  in  appearance. 

PERCUSSION  CAPS.  See  Fulmina- 
ting Mercury-. 

PERCUSSION  LOCKS  have  no  pan. 
In  the  place  of  the  pan,  a  small  tube  pro- 
jects horizontally  from  the  side  of  the 
gun,  and  in  this  tube  another  small  tube 
stands  perpendicularly.  The  cock,  in- 
stead of  being  formed  to  hold  a  flint,  is 
shaped  somewhat  like  a  hammer,  with  a 
hollow  to  fit  upon  the  last  tube.  On  thia 
tube  a  little  cap  of  copper  is  placed,  in 
the  bottom  of  which  is  a  chemical  mix- 
ture that  kindles  by  percussion.  This 
percussion  is  produced  by  the  cock, 
which  therefore  requires  a  very  strong 
spring. 

The  powder  is  made  of  different  ma- 
terials 5  among  others,  of  mercury,  puri- 
fied nitric  acid,  and  spirit  of  wine 
freed  from  water.  The  copper-caps  in 
which  this  powder  is  placed  are  two  and 
a  half  lines  long  and  two  lines  wide. 
Sometimes  the  powder  is  also  formed  in 
pills,  and  then  a  somewhat  different  con- 
trivance is  required  to  place  the  pills, 
covered  with  a  little  wax,  to  protect  tliem 
from  moisture,  in  the  small  tube. 

PERFORATING  GLASS,  Earthen- 
ware, &c.  The  only  tools  requisite  for 
this  are  a  few  worn  out  three -edged 
hand-saw  files.  These  being  generally 
made  of  cast  steel,  retain  when  ground 
a  very  fine  point,  which  is  of  the  utmost 
importance.  In  order,  however,  to  give 
them  the  requisite  degree  of  hardness, 
it  is  necessary  to  make  their  ends,  for 
about  an  inch,  red  hot,  and  then  plunge 
them  into  cold  water.  By  this  treatment 
they  become  hard  and  brittle  ;  care  is, 
therefore,  required  in  grinding  them  to 
a  proper  point,  which  is  easily  effected  on 
a  common  grindstone.  There  generally  is 
given  to  them  a  few  rubs  on  a  fine  oil-stone 
after  the  grinding,  so  as  to  produce  a 
very  fine  point.  A  cylindrical  piece  of 
any  sort  of  wood,  about  two  inches  long, 
terminated  by  a  half-round  end,  having 
a  hole  about  the  tenth  of  an  inch  in  di- 
ameter, through  its  axis,  may  either  be 
fastened  into  a  common  bench  vice,  or 
on  a  table.  This  constitutes  the  only 
support  required.  Suppose  that  a  glass 
to  cover  the  face  of  a  wheel  barometer  ia 
wanted,  through  which  it  is  sometimea 
necessary  to  make  a  perforation  for  the 
purpose  of  passing  the  screw  of  the  non- 


448 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PER 


ious  through  :  a  proper  piece  of  glass 
being  >  elected,  is  to  be  marked  with  a 
dot  of  ink  on  the  place  where  the  intend- 
ed perforation  is  to  be  made  ;  the  gla<s 
is  then  to  be  held  horizontally  by  the 
left  hand,  and  immediately  over  the 
hole  in  the  wood  support  above  men- 
tioned. A  three-edged  file  having  been 
hardened  and  ground  to  a  fine  point  in 
the  manner  above  described,  is  held 
firmly  between  the  fore-finger  and  thumb 
of  the  right  hand,  precisely  in  the  posi- 
tion that  a  pen  or  pencil  is  retained  when 
writing.  The  pointed  steel  is  then  to  be 
repeatedly  impinged  against  the  glass 
over  the  spot  intended  to  be  perforated, 
taking  care  not  to  use  too  much  violence. 
In  a  short  time  the  outer  surface  is  re- 
moved, and,  by  a  continuation  of  the  pro- 
cess, a  conical  piece  is  forced  from  the 
under  surface  of  the  glass  through  a 
hole  in  the  wood  support ;  the  perfora- 
tion so  produced  never  exceeds  in  size  a 
pin's  head,  but  may  be  made  as  large  as 
required  by  holding  it  over  the  hole  in 
the  support,  and  working  round  its  edge 
with  a  fine  pointed  file.  In  this  way, 
after  a  little  practice,  and  in  a  very  few 
minutes  may  be  perforated,  with  ease, 
all  descriptions  of  glass,  from  the  thin- 
nest crown  to  the  thickest  plate,  without 
any  danger. 

Wine-glasses  or  tumblers  may,  also,  be 
easily  perforated  in  a  similar  manner ;  but 
there  is  mostly  employed  another  process 
for  them.  These  being  made  of  a  softer 
sort  of  glass,  require  only  to  be  moved 
by  the  hand  backwards  and  forwards,  in 
the  manner  of  drilling,  on  the  sharp 
point  of  the  file,  with  the  occasional  as- 
sistance of  a  little  oil  and  emery.  In- 
deed any  sort  of  glass  may  be  perforated 
in  this  manner,  but  not  so  quickly  as  by 
the  method  of  punching.  All  the  varie- 
ties of  china  and  earthenware  may  be 
perforated  by  either  of  the  above  pro- 
cesses with  certainty. 

PERFUMERY.— Dr.  Ure  in  his  Diction- 
ary of  the  Arts,  gives  the  following  di- 
rections for  obtaining  and  preparing  the 
most  important  essences,  &c,  which  are 
slightly  condensed.  The  essential  oils  or 
essences  obtained  in  the  south  of  France 
are  those  of  roses,  neroli,  petit-grain, 
lavender,  wild-thyme,  thyme,  and  rose- 
mary. These  essences  are  distilled  in 
the  usual  manner.  They  obtain,  by  put- 
ting into  the  body  of  the  still  40  lbs.  of 
rose  leaves,  and  30  pints  of  water,  and 
proceeding  to  distillation,  15  pints  of 
rose-water.  They  then  continue  the 
operation  until  they  have  obtained  200 


pints  of  water,  termed  No.  1.  In  this 
first  distillation,  they  obtain  an  almost 
imperceptible  quantity  of  the  essence  of 
roses  ;  but  in  the  second  it  becomes  more 
apparent ;  and,  finally,  in  the  fifth  it  be- 
comes notable. 

In  the  distillation  of  orange-flowers, 
they  also  obtain  the  essence  of  neroli,  now 
become  of  remarkable  importance.  If 
they  would  obtain  this  essence  they  fol- 
low the  ordinary  process,  and  repass  the 
waters  of  the  first  distillations  upon  new 
flowers.  On  the  contrary,  when  it  is  in- 
tended to  prepare  orange-flower  water  of 
a  good  quality,  they  draw  off  a  fifth  part 
only  of  the  water  placed  in  the  cucurbit. 

Of  pommade-s  by  infusion. — Rose,  or- 
ange-flower, and  cassia.  Take  334  pounds 
of  hog's  lard,  and  166  of  beef  suet.  These 
500  pounds  are  put  into  a  pan  called  biiga- 
dier  ;  and  when  melted,  150  pounds  of 
rose-leaves  nicely  plucked  are  added,  tak- 
ing care  to  stir  the  mixture  every  hour. 
The  infusion  thus  prepared  is  to  remain 
at  rest  for  24  hours  ;  at  the  end  of  this 
time,  the  pommade  is  again  melted,  and 
well  stirred  to  prevent  "its  adherence  to 
the  bottom  of  the  melting-pan.  The 
mass  is  now  to  be  poured  out  into  canvas, 
and  made  into  rectangular  bricks  or 
loaves,  which  are  subjected  to  a  press,  in 
order  to  separate  the  solid  matter  from 
the  soft  pommade.  These  brick-shaped 
pieces  being  put  into  an  iron-bound  barrel 
perforated  all  over  its  staves,  the  pommade 
is  to  be  allowed  to  exude  on  all  sides, 
and  flow  down  into  a  copper  vessel 
placed  under  the  trough  of  the  press. 
This  manipulation  should  be  repeated 
with  the  same  fat  ten  or  twelve  times  ; 
or  in  other  words,  3000  pounds  of  fresh 
rose-leaves  should  be  employed  to  make 
a  good  pommade. 

The  pommade  of  orange-flowers  is 
made  in  the  same  manner,  as  also  the 
pommade  of  cassia. 

Of  pommades  without  infusion. — Jas- 
mine, tuberose,  jonquil,  narcissus,  and 
violet. 

A  square  frame,  called  tiame,  is  made 
of  four  pieces  of  wood,  well  joined  to- 
gether, 2  or  3  inches  deep,  into  which  a 
pane  of  glass  is  laid,  resting  upon  inside 
ledges  near  the  bottom.  Upon  the  sur- 
face of  the  pane  the  simple  pommade  of 
hog's  lard  and  suet  is  spread  with  a  pal- 
let knife  ;  and  into  this  pommade  the 
sweet  scented  flowers  are  stuck  fresh  in 
different  points  each  successive  day,  du- 
ring two  or  three  months,  till  the  pom- 
made has  acquired  the  desired  richness 
of  perfume. 


per] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


449 


Of  Oils. — Kose,  orange-flower,  and 
cassia  oils,  are  made  by  infusion,  lite  the 
pommades  of  the  same  perfumes  ;  taking 
care  to  select  oils  perfectly  fresh.  As  to 
those  of  jasmine,  tuberose,  jonquil,  vio- 
let, and  generally  all  delicate  flowers,  they 
are  made  in  the  following  manner.  Upon 
an  iron  frame,  a  piece  of  cotton  cloth  is 
stretched,  imbued  with  olive  oil  of  the 
first  quality,  and  covered  completely  with 
a  thin  bed  of  flowers.  Another  frame  is 
similarly  treated,  and  in  this  way  a  pile 
is  made.  The  flowers  must  be  renewed 
till  the  oil  is  saturated  with  their  odor. 
The  pieces  of  cotton  cloth  are  then  care- 
fully pressed  to  extrude  the  oil.  This 
last  operation  requires  commonly  7  or  8 
days. 

Essence  of  Hoses. — Put  into  the  body 
of  a  still  40  pounds  of  roses,  and  60 
quarts  of  water  ;  distil  off  one  half  of 
the  water.  When  a  considerable  quan- 
tity of  such  water  of  the  first  distillation 
is  obtained,  it  must  be  used  as  water  upon 
fresh  rose-leaves  ;  a  process  of  repeti- 
tion to  be  carried  to  the  fifth  time.  In 
the  distillation  of  orange-flower,  to  ob- 
tain the  essence  of  neroli,  the  same  pro- 
cess is  to  be  followed  ;  but  if  orange- 
flower  water  merely  be  wanted,  then  it  is 
obtained  at  one  distillation,  by  reserving 
the  first  fifth  part  of  water  that  comes 
over.  What  is  called  the  essence  of  pet- 
it-grain, is  obtained  by  distilling  the 
leaves  of  the  orange  shrub. 

Of  scented  spirits,  from  oil  of  rose,  or- 
ange, iasmine,  tuberose,  cassia,  violet, 
and  other  flowers. 

Into  each  of  three  digesters,  immersed 
in  water-baths,  put  25  lbs.  of  any  one  of 
these  oils,  and  pour  into  the  first  diges- 
ter 25  quarts  ot  spirits  of  wine  ;  agitate 
every  quarter  of  an  hour  during  three 
days,  and  at  the  end  of  this  period, 
draw  off  the  perfumed  spirit,  and  pour 
it  into  the  second  digester  ;  then  trans- 
fer it  after  3  days  into  the  third  digester, 
treating  the  mixture  in  the  same  way  ; 
and  the  spirit  thus  obtained  will  be  per- 
fect. The  digesters  must  be  carefully 
covered  during  the  progress  of  these  ope- 
rations. On  pursuing  the  same  process 
with  the  same  oil  and  fresh  alcohol,  es- 
sences of  inferior  qualities  may  be  ob- 
tained, called  Nos.  2,  3,  and  4. 

Esprit  de  Sawve. 

1  Eng.  qrts.  of  spirits  of  jasmine,  3d  operation. 
T  do.  cassia,         do. 

8  do.  wine. 

2  do.  tuberose,    do. 
IX  ounces  of  essence  of  cloves. 

H  ounce  fine  neroli. 


1%  ounce  essence  of  bcrgamot 

8  ounces  of  essence  of  musk,  2d  infusion. 

3  quarts  of  rose  water. 

Spirit  of  Cytherea. 
quart  spirit  of  violets. 

do.  jasmine,  2d  operation, 

do.  tuberose,        do. 

do.  clove  gillyflower, 

do.  roses,  2d  operation, 

do.  Portugal. 

2  do.  orange-flower  water. 

Spirit  of  Flowers  of  Italy. 
2  quarts  of  spirit  of  jasmine,  2d  operation. 
2  do  roses,  do. 

2  do.  orange,  3d        do. 

2  do.  cassia,    2d        do. 

1J4  do.  orange-flower  water. 

The  above  spirits  mark  usually  28  al- 
cometric  degrees  of  Gay  Lussac.  (See  Al- 
cohol.) 

Pommade. — No  less  than  20  scented 
pommades  are  distinguished  by  the  per- 
fumers of  Paris.  The  essences  commonly 
employed  in  the  manufacture  of  pom- 
mades, are  those  of  bergamot,  lemons, 
codrat,  limette  (sweet  lemon),  Portugal, 
rosemary,  thyme,  lemon  thyme,  lavender, 
marjoram,  and  cinnamon. 

The  following  may  serve  as  an  ex- 
ample : — 

Pommade  a  la  Vanille,  commonly  called  Ro- 
man. 
12  pounds  of  pommade  a  la  rose. 
8       do.        oil  ^  la  rose. 
1        do.        vanilla,  first  quality,  pulverized. 
6  ounces      bergamot 

The  pommade  being  placed  at  the  heat 
of  a  water-bath,  the  vanilla  is  to  be  in- 
troduced with  continual  stirring  for  an 
hour.  The  mixture  is  left  to  settle  during 
two  hours.  The  pommade  is  then  to  be 
drawn  off,  and  will  be  found  to  have  a 
fine  yellow  color,  instead  of  the  brown 
shade  which  it  commonly  has. 

In  making  odoriferous  extracts  and 
waters,  the  spirits  of  the  flowers  prepared 
by  macerating  the  flowers  in  alcohol 
should  be  preferred  to  their  distillation, 
as  forming  the  foundation  of  good  per- 
fumery. The  specific  gravity  of  these 
spirits*  should  be  always  under  0*88. 

Extract  of  Nosegay  (Bouquet). 

2  quarts  spirit  of  jasmine,  1st  operation. 
2    do.     extract  of  violets, 
1     do.     spirit  of  cassia,  1st         do. 
1    do.    roses,        do.      1st         do. 
1     do.     orange,      do.      1st         do. 
1     do.     extract  of  clove  gillyflower. 

4  drms.  of  flowers  of  benzoin  (benzoic  acid). 
8  ounces  of  essence  of  amber,  1st  infusion. 


450 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[pew 


Extract  of  Peach  Blossoms. 
6  quarts  of  spirits  of  wine. 
6  pounds  of  bitter  almonds. 

2  quarts  of  spirits  of  orange-flower,  2d  operation. 
4  drachms  of  essence  of  bitter  almonds. 

4  drachms  of  balsam  of  Peru. 
4  ounces  of  essence  of  lemons. 

Eau  de  Cologne. — Two  processes  have 
been  adopted  for  the  preparation  of  this 
perfume,  distillation  and  infusion  ;  the 
first  of  which,  though  generally  aban- 
doned, is,  however,  the  preferable  one. 
The  only  essences  which  should  be  em- 
ployed, and  which  have  given  such  ce- 
lebrity to  this  water,  are  the  following  : 
bergamot,  lemon,  rosemary,  Portugal, 
neroli.  The  whole  of  them  ought  to  be 
of  the  best  quality,  but  their  proportions 
may  be  varied  according  to  the  taste  of 
the  consumers. 

Thirty  different  odors  are  enumerated 
by  perfumers  :  the  following  recipes  will 
form  a  sufficient  specimen  of  their  com- 
binations. 

Iloney  Water. 
6  quarts  of  spirits  of  roses,  3d  operation. 
8    do.  jasmine. 

3  do.  spirits  of  wine. 

3  ounces  essence  of  Portugal. 

4  drachms  of  flowers  of  benzoin. 

12  ounces  of  essence  of  vanilla,  3d  infusion. 
12    do.  musk,  do. 

3  quarts  good  orange-flower  water. 


Eau  de  Mille  Eleurs. 

IS 
4 
8 
4 

1 
1 

8 

quarts  of  spirits  of  wine, 
ounces  balsam  of  Peru. 

do.    essence  of  bergamot 

do.                      cloves. 

do.    ordinary  neroli. 

do.                   thyme. 

do.                   musk,  3d  infusion. 

4  quarts  orange-flower  water. 

Eau  de  Mousseline. 
2  quarts  spirit  of  roses,  3d  infusion. 
2    do.  jasmine,  4th  do. 

1  do.  clove  gillyflower. 

2  do.  orange-flower,  4th  infusion. 
2  ounces  essence  of  vanilla,  3d  do. 

1  do.  musk,  do. 

2  drachms  of  sanders  wood. 

1  quart  of  orange-flower  water. 

Almond  Pastes. — These  are,  gray,  sweet 
white,  and  bitter  white. 

The  first  is  made  either  with  the  ker- 
nels of  apricots,  or  with  bitter  almonds. 
They  are  winnowed,  ground,  and  formed 
into  loaves  of  5  or  6  pounds  weight, 
which  are  pat  into  the  press  in  order  to 
extract  their  oil ;  300  pounds  of  almonds 
affording  about  130  of  oil.  The  pressure 
is  increased  upon  them  every  two  hours 
during  three  days  ;  at  the  end  of  which 


time  the  loaves  or  cakes  are  taken  out  of 
the  press  to  be  dried,  ground,  and  sifted. 

PERSIAN  WHEEL.  In  mechanics,  a 
contrivance  for  raising  water  to  some 
height  above  the  level  of  a  stream.  In 
the  rim  of  a  wheel  turned  by  the  stream 
a  number  of  strong  pins  are  fixed,  from 
which  buckets  are  suspended.  As  the 
wheel  turns,  the  buckets  on  one  side  go 
down  into  the  stream,  where  they  are  fill- 
ed, and  return  up  full  on  the  other  side 
till  they  reach  the  top.  Here  an  obstacle 
is  placed  in  such  a  position  that  the  buck- 
ets successively  strike  against  it  and  are 
overset,  and  the  water  emptied  into  a 
trough.  As  the  water  can  never  be  raised 
by  this  means  higher  than  the  diameter 
of  the  wheel,  it  is  obvious  that  this  rude 
machine  is  capable  of  only  a  very  limited 
application.  Sometimes  the  wheel  is 
made  to  raise  the  water  only  to  the  height 
of  the  axis.  In  this  case,  instead  of 
buckets,  the  spokes  are  made  hollow,  and 
bent  into  such  a  form  that  when  they  dip 
into  the  water  it  runs  into  them,  and  is 
thus  conveyed  to  a  box  on  the  axle, 
whence  it  is  emptied  into  a  cistern.  Sucn 
wheels  are  in  common  use  on  the  banks 
of  the  Nile,  and  elsewhere. 

PETALITE.  A  Swedish  mineral  of  a 
gray  or  reddish  color  and  a  foliated  tex- 
ture. It  is  a  silicate  of  alumina  and  lithia, 
and  contains  between  five  and  six  per  cent, 
of  the  latter  alkali. 

PETROLEUM.  A  brown  liquid  bitu- 
men, found  in  several  parts  of  Europe,  in 
Persia,  and  In  the  West  Indies.  It  is 
often  termed  Barbadoes  tar. 

PETROLINE.  A  substance  obtained 
by  distilling  the  petroleum  of  Rangoon  ; 
analogous  to  paraMne. 

PETROSILE3C  A  variety  of  flint  or 
hornstone.  The  term  is  sometimes  ap- 
plied to  compact  feldspar. 

PETUNTZE.  A  decomposing  variety 
of  feldspar,  used  in  China  in  the  manufac- 
ture of  porcelain. 

PEWTER,  PEWTEEER.  Pewter  is. 
generally  speaking,  an  alloy  of  tin  and 
lead,  sometimes  with  a  little  antimony  or 
copper,  combined  in  several  different  pro- 
portions, according  to  the  purposes  which 
the  metal  is  to  serve.  Plate  pewter  has  a 
bright  silvery  lustre  when  polished  ;  the 
best  is  composed  of  100  parts  of  tin,  8 
parts  of  antimony,  2  parts  of  bismuth, 
and  2  of  copper.  The  trifle  is  said  by 
some  to  consist  of  83  of  tin,  and  17  of  an- 
timony ;  but  it  generally  contains  a  good 
deal  of  lead.  The  ley  pewter  is  composed 
of  4  of  tin,  and  1  of  lead.  As  the  tenden- 
cy of  the  covetous  pewterer  is  always  to 


pha] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


451 


put  in  as  much  of  the  cheap  metal  as  is 
compatible  with  the  appearance  of  his 
metal  in  the  market,  ana  as  an  excess  of 
lead  may  cause  it  to  act  poisonously  upon 
all  vinegars  and  many  wines,  the  French 
government  long  ago  appointed  Fourcroy, 
Vauquelin,  and  other  chemists,  to  ascer- 
tain by  experiment  the  proper  proportions 
of  a  safe  pewter  alloy.  These  commis- 
sioners found  that  18  parts  of  lead  might, 
without  danger  of  aftecting  wines,  &c, 
be  alloyed  with  82  parts  of  tin ;  and  the 
French  government  in  consequence  pass- 
ed a  law  requiring  pewterers  to  use  83i 
of  tin  in  100  parts,  with  a  tolerance  of  er- 
ror amounting  to  li  per  cent.  This  or- 
donnance,  allowing  not  more  than  18  per 
cent,  of  lead  at  a  maximum,  has  been  ex- 
tended to  all  vessels  destined  to  contain 
alimentary  substances.  A  table  of  speci- 
fic gravities  was  also  published,  on  pur- 
pose to  test  the  quality  of  the  alloy  ;  the 
density  of  which,  at  the  legal  standard,  is 
7-764.  Any  excess  of  lead  is  immediately 
indicated  by  an  increase  in  the  specific 
gravity  above  that  number. 

The  pewterer  fashions  almost  all  his  ar- 
ticles by  casting  them  in  moulds  of  brass 
or  bronze,  which  are  made  both  inside 
and  outside  in  various  pieces,  nicely  fit- 
ted together,  and  locked  in  their  positions 
by  ears  and  catches  or  pins  of  various 
kinds.  The  moulds  must  be  moderately 
heated  before  the  pewter  is  poured  into 
them,  and  their  surfaces  should  be  brush- 
ed evenly  over  with  pounce  powder  (san- 
darach)  beaten  up  with  white  of  egg. 
Sometimes  a  film  of  oil  is  preferred.  The 
pieces,  after  being  cast,  are  turned  and 
polished  ;  and  if  any  part  needs  soldering, 
it  must  be  done  with  a  fusible  alloy  of  tin, 
bismuth,  and  lead. 

Britannia  metal,  the  kind  of  pewter  of 
which  English  tea-pots  are  made,  is  said 
to  be  an  alloy  of  equal  parts  of  brass,  tin, 
antimony,  and  bismuth  ;  but  the  propor- 
tions differ  in  different  workshops,  and 
much  more  tin  is  commonly  introduced. 
Queen's  metal  is  said  to  consist  of  9  parts 
of  tin,  1  of  antimony,  1  of  bismuth,  andl 
of  lead ;  it  serves  also  for  tea-pots  and 
other  domestic  utensils. 

PHANTASCOPE.  A  curious  instru- 
ment invented  by  Prof.  John  Locke, 
which  will  illustrate,  in  a  manner  never 
before  accomplished,  "single  vision  by 
each  eye."  It  is  very  simple,  and  has 
neither  lenses,  prisms,  nor  reflectors.  It 
consists  of  a  flat  board  base,  about  nine 
by  eleven  inches,  with  two  upright  rods, 
one  at  each  end,  a  horizontal  strip  con- 
necting the  upper  ends  of  the  uprights, 


and  a  screen  or  diaphragm,  nearly  as 
largo  as  the  base,  interposed  between  the 
top  strip  and  the  tubular  base,  this  screen 
being  adjustable  to  any  intermediate 
height.  The  top  strip  has  a  slit  one- 
fourth  of  an  inch  wide,  and  about  three 
inches  long  from  left  to  right.  The  ob- 
server places  his  eyes  over  this  slit,  look- 
ing downward.  The  movable  screen  has 
also  a  slit  of  the  same  length,  but  about 
an  inch  wide.  If  there  are  two  identical 
pictures  of  a  flower,  about  one  inch  in  di- 
ameter, placed  the  one  to  the  left  and  the 
other  to  the  right  of  the  centre  of  the  ta- 
bular base,  or  board  forming  the  support, 
and  about  two  and  a  half  or  three  inches 
apart  from  centre  to  centre.  A  flower- 
pot or  vase  is  painted  on  the  upper  screen, 
at  the  centre  of  it  as  regards  right  and 
left,  and  with  its  top  even  with  the  lower 
edge  of  the  open  slit.  By  looking  down- 
ward through  the  upper  slit,  and  direct 
ing  both  eyes  steadily  to  a  mark,  a  quasi 
stem,  in  the  flower  pot  or  vase — instantly 
a  flower  similar  to  one  of  those  on  the 
lower  screen,  but  of  half  the  size,  will  ap- 
pear growing  out  of  the  vase,  and  in  the 
open  slit  of  the  moveable  screen.  On 
directing  the  attention  through  the  upper 
screen  to  the  base,  this  phantom  flower 
disappears,  and  only  the  two  pictures  on 
each  side  of  the  place  of  the  phantom  re- 
main. The  phantom  itself  consists  of  the 
two  images  painted  on  the  base,  optically 
superimposed  on  each  other.  If  one  of 
these  images  be  red  and  the  other  blue, 
the  phantom  will  be  purple.  If  two  iden- 
tical figures  of  persons  be  placed  at  the 
proper  positions  on  the  lower  screen,  and 
the  upper  screen  be  gradually  slid  up 
from  its  lowest  point,  the  eye  being  di- 
rected to  the  index,  each  image  will  at 
first  be  doubled,  and  will  gradually  re- 
cede, there  being  of  course  four  in  view 
until  the  two  contiguous  coincide,  when 
three  only  are  seen.  This  is  the  proper 
point  where  the  middle  or  double  image 
is  the  phantom  seen  in  the  air.  If  the 
screen  oe  raised  higher,  then  the  middle 
images  pass  by  each  other,  and  again  four 
are  seen  receding  more  and  more  as  the 
screen  is  raised. 

As  all  this  is  the  effect  of  crossing  the 
axes  of  the  eyes,  it  follows  that  a  person 
with  only  one  perfect  eye  cannot  make 
the  experiments.  They  depend  on  binoc- 
ular vision. 

All  these  effects  depend  on  the  princi- 
ple that  one  of  the  two  primitive  pictures 
is  seen  by  one  eye,  and  the  other  by  the 
other  eye,  and  that  the  axes  are  so  con- 
vergedby  looking  at  the  index  or  mark 


452 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PHO 


on  the  upper  screen  that  those  separate 
images  fall  on  the  points  in  the  eye,  which 

Eroduce  single  vision.  To  a  person  who 
as  perfect  voluntary  control  over  the 
axes  of  his  eyes,  the  upper  screen  and  in- 
dex are  unnecessary.  Such  an  observer 
can  at  any  time  look  two  contiguous  per- 
sons into  one,  or  superimpose  the  image 
of  one  upon  the  image  of  the  other. 

PHOSGENE  GAS.  A  compound  of 
chlorine  and  carbonic  oxide,  made  by  ex- 
posing equal  measures  of  those  gases  to 
the  sunshine,  or  to  bright  daylight.  They 
will  not  unite  in  the  dark. 

PHOSPHATES.  Salts  containing  phos- 
phoric acid. 

PHOSPHITES.  Salts  containing  phos- 
phorous acid. 

PHOSPHORESCENCE.  The  emission 
of  light  by  substances  at  common  temper- 
atures, or  below  a  red  heat. 

PHOSPHATE  OF  SODA  is  made  by 
dissolving  14  parts  of  crystallized  carbo- 
nate of  soda  in  21  of  water,  at  150°  ;  to 
this  is  to  be  added,  gradually,  5  of  phos- 
phoric acid,  sp.  gr.  1-85,  boiling  the  mix- 
ture for  a  few  minutes,  filtering  it,  and 
letting  it  crystallize  by  cooling ;  from  14 
to  15  of  phosphate  of  soda  crystallizes. 

It  is  now  extensively  used  in  the  arts 
of  calico  printing  and  dyeing. 

PHOSPHORESCENCE  is  the  proper- 
ty which  certain  bodies  possess,  of  be- 
coming luminous  without  undergoing 
combustion,  as,  when  we  rub  or  heat 
them,  or  in  consequence  of  the  action  of 
the  living  principle,  or  of  decomposition. 
Two  pieces  of  quartz  emit  light  on  being 
rubbed  together.  Light  is  seen  in  break- 
ing lumps  of  sugar.  A  variety  of  blende 
(snlphuret  of  zinc),  on  being  scratched 
with  a  knife,  emits  a  fine  yellow  light. 

PHOSPHORIC  ACID  is  present  in  the 
solid  parts  of  all  animals,  and  displayed- 
especially  in  the  urine.  By  Barry's  ex- 
periments, it  appeared  in  all  pharmaceu- 
tical extracts,  and  it  exists  in  all  articles 
of  food,  and,  as  phosphate  of  lime,  exists 
v  in  bones,  and  in  all  vegetables.  It  ap- 
pears in  all  the  substances  of  animals,  and 
their  products.  In  the  mineral  kingdom, 
it  is  found  in  lead  and  iron,  in  silex,  in 
calcareous  earths,  and  in  union  with  lime, 
sometimes  in  whole  mountains,  as  in 
Spain  and  Hungary.  The  acid  is  formed 
by  the  combustion  of  phosphorus,  and,  so 
to  speak,  is  an  oxide.  But  it  is  also  made 
by  distilling  phosphorus  with  nitric  acid, 
or  with  sulphuric  acid  or  chlorine.  It  is 
soluble  in  water,  which  takes  up  1-687 
with  increase  of  temperature.  Distilled 
with  charcoal  or  inflammables,  they  ab- 


stract its  oxygen,  and  it  returns  to  the 
state  of  phosphorus. 

Phospnoric  acid  and  barytes  form  a 
salt,  which,  with  great  heat,  forms  gray 
enamel. 

Phosphoric  acid  and  lime,  or  phosphate 
of  lime,  is  insoluble  in  water  till  calcined. 
j  It  absorbs  grease,  and  serves  to  polish 
stones  and  metallic  surfaces.  {See  Phos- 
phorite.) 

Phosphates  of  potash  and  soda  are 
made,  and  the  latter  is  used,  as  a  purga- 
tive salt,  having  no  flavor  ;  also  in  assays, 
and  in  soldering. 

Phosphate  of  ammonia  abounds  in 
urine,  and  much  employed  as  a  flux,  and 
in  coloring  glass. 

Other  pnosphates  are  formed,  but  not 
applied  to  any  purpose. 

PHOSPHORUS.  So  called  from  its 
property  of  shining  in  the  dark.  It  was 
discovered  in  1668  by  Brandt,  an  alche- 
mist of  Hamburgh,  and  was  originally 
obtained  by  distilling  urine ;  but  it  is  now 
always  extracted  from  bone  earth,  by  a 
process  contrived  by  Scheele.  The  bones 
are  calcined,  so  as  to  destroy  the  animal 
matter,  and,  being  powdered,  are  mixed 
with  water,  to  which  half  their  weight  of 
sulphuric  acid  is  added.  The  bone  earth, 
consisting  chiefly  of  phosphate  of  lime,  is 
thus  decomposed,  sulphate  of  lime  is 
formed,  and  phosphoric  acid  is  evolved ; 
or,  rather,  superphosphate  of  lime,  which, 
being  much  more  soluble  than  the  sul- 
phate, remains  in  the  liquid,  and  may  be 
obtained  by  its  evaporation ;  it  is  mixed 
with  about  half  its  weight  of  charcoal,  and 

Eut  into  a  well-luted  earthen  retort,  the 
eak  of  which  dips  into  water.  At  a 
bright  red  heat,  the  phosphorus  distils 
over  into  the  water.  It  is  purified  by 
carefully  melting  it  under  water,  and 
straining  it  through  a  piece  of  chamois 
leather. 

Pure  phosphorus  is  almost  colorless, 
and  semi-  transparent ;  it  may  be  cut  with 
a  knife,  aud  its  surface  has  a  waxy  lustre. 
It  fuses  at  108°,  boils  at  550°,  and  is  con- 
verted into  vapor,  having,  according  to 
Dumas,  a  density  =  4-35.  It  is  sparingly 
soluble  in  fixed  and  volatile  oils,  and  in 
ether  and  alcohol ;  but  insoluble  in  water. 
It  shines  in  the  dark,  and  emits  a  lumin- 
ous vapor,  undergoing  a  slow  combustion, 
and  exhaling  a  peculiar  smell  like  garlic. 
When  rubbed,  or  heated  to  a  temperature 
of  about  110°,  it  takes  fire  and  burns  with 
great  rapidity,  with  a  white  flame,  emit- 
ting abundance  of  acid  fumes ;  in  oxygen 
gas  its  combustion  is  so  intensely  brilliant 
that  the  eye  can  scarcely  bear  the  light. 


PHO] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


453 


The  product  of  the  perfect  combustion 
of  phosphorus  is  phosphoric  acid,  a  fusible 
substance,  very  soluble  in  water,  and  in- 
tensely sour.  It  appears  to  consist  of  1 
equivalent  of  phosphorus  =  16,  and  2k  of 
oxygen  =  20  ;  its  equivalent  being  36. 

There  are  two  other  acids  of  phospho- 
rus :  namely,  the  phosphorous  acid,  con- 
sisting of  16  phosphorus +  12  oxygen; 
and  the  hypophosphorovs  acid,  which  ap- 
pears to  be  a  compound  of  2  equivalents 
of  phosphorus  (16  X  2)  s=  32,  and  1  of  oxy- 
gen =  8.  When  phosphorus  is  boiled  in 
a  solution  of  caustic  potash  a  gas  is  evolv- 
ed, which  is  remarkably  distinguished  by 
its  spontaneous  inflammability  ;  each  bub- 
ble, as  it  rises  through  the  water,  taking 
fire  upon  the  surface,  and  producing  a 
beautiful  ring  of  smoke  :  this  gas  is  com- 
monly called  phosphuretted  hydrogen. 
Phosphorus  may  be  made  to  combine  with 
the  greater  number  of  the  metals,  forming 
compounds  called phosphurets. 

Wohler  recommends,  as  likely  to  afford 
phosphorus  at  a  very  cheap  rate,  to  distil 
by  a  strong  heat  ivory  black,  with  half  its 
weight  of  fine  sand  and  charcoal  powder. 
A  silicate  of  lime  is  formed,  and  the  car- 
bonic oxide  and  phosphorus  come  over. 

If  phosphorus  be  put  with  alcohol  into 
a  bottle,  and  shaken  for  some  time,  it 
may  be  obtained  in  powder  of  the  utmost 
tenuity,  which,  when  diffused  through 
the  alcohol,  appears  as  if  it  consisted  ot  a 
multitude  of  minute  crystals. 

At  the  temperature  of  60°  F.,  or  up- 
wards, carbon  in  the  form  of  animal  char- 
coal, or  lamp-black,  causes  the  inflamma- 
tion of  a  stick  of  phosphorus  powdered 
with  it,  and  the  effect  takes  place  either 
in  the  open  air,  or  in  a  close  receiver  of  a 
moderate  size. 

Phosphorus  Bottle. — In  a  phial,  mix,  by 
gentle  heat  for  half  an  hour,  2  drs.  of 
phosphorus,  with  1  dr.  of  lime.  Or,  in  a 
phial,  with  water,  melt  1  dr.  of  phospho- 
rus, and  15  grs.  of  white  wax.  On  cool- 
ing, as  the  mass  grows  solid,  turn  the 
phial  till  the  inside  is  coated,  when  dis- 
charge the  water,  and  dry  cool. 

Canton's  Phosphorus  is  formed  by  mix- 
ing three  parts  of  calcined  oyster-shells  in 
powder,  with  one  of  flowers  of  sulphur, 
and  ramming  the  mixture  into  a  crucible, 
and  igniting  it  for  half  an  hour.  The 
bright  parts  will,  on  exposure  to  the  sun- 
beam, or  to  the  common  daylight,  or  to 
an  electrical  explosion,  acquire  the  pro- 
perty of  shining  in  the  dark,  so  as  to  illu- 
minate the  dial  of  a  watch.  It  will,  after 
a  while,  cease  to  shine ;  but,  if  we  keep 
the  powder  in  a  well-corked  phial,  a  new 


exposure  to  the  sun's  light  will  restore 
the  phosphorescent  quality. 

Temperature  has  a  marked  effect  on  the 
emission  of  light  by  these  bodies.  When 
they  are  shining,  the  luminous  appearance 
ceases  if  they  are  exposed  to  the  cold  of  a 
freezing  mixture.  It  becomes  more  vivid 
by  applying  heat ;  and  if  it  has  ceased,  it 
may  be  renewed  by  applying  a  stronger 
heat,  so  that  a  piece  of  any  solar  phospho- 
rus, which  has  apparently  lost  its  power, 
may  by  heat  be  again  made  to  shine, 
Some  of  the  phosphorescent  bodies  just 
mentioned,  after  their  luminousness  is 
over,  upon  partially  heated  iron,  yield  on 
fusion  a  very  vivid  light.  Lime  is  the 
substance  possessing  this  property  in  the 
most  remarkable  degree.  It  a  piece  of 
calcareous  spar  is  placed  on  charcoal  be- 
fore the  compound  blow-pipe,  it  emits  a 
light  so  vivid  and  white  that  it  can  scarce- 
ly be  looked  upon. 

Phosphorus  Match  Light. — Into  a  large 
flask,  heated  in  a  sand-bath,  put  eight 
parts  of  pure  phosphorus,  which  half 
melt,  without  allowing  it  to  oxidize.  Add 
four  equal  parts  of  magnesia ;  begin  to 
mix  the  whole  at  a  heat  of  234-5°  ;  reduce 
the  heat  gradually  to  106-25°,  and  in 
about  an  hour  you  will  have  a  fatty  pow- 
der, which  is  to  be  put  into  bottles,  and, 
when  cold,  carefully  stopped.  This  sub- 
stance will  instantly  inflame  a  common 
match. 

PHOTOGRAPHY,  or  Heliograph y. 
Under  the  article  Daguerreotype,  full  men- 
tion of  the  action  of  the  salts  of  silver  un- 
der the  influence  of  light  has  been  de- 
scribed. Photographic  processes  require 
no  silver  plate,  making  use  of  paper  or 
some  non-conducting  material  and  apply- 
ing on  its  surface  sensitive  salts  of  silver, 
which  are  to  be  protected  from  the  light 
until  they  are  ready  to  be  exposed  in  the 
camera. 

The  term  "  Photogenic  Drawing  "  has 
usually  been  applied  to  representations  of 
various  objects  upon  paper  imbued  with 
some  of  the  salts  of  silver.  If  a  piece  of 
paper  be  dipped  into  a  weak  solution  of 
nitrate  of  silver,  carefully  dried,  and  pre- 
served out  of  the  contact  of  light,  it  re- 
mains white ;  but  if  exposed  to  light  it 
gradually  becomes  discolored,  acquiring  a 
brownish  or  gray  tint,  and  ultimately 
blackens,  the  depth  of  color  depending 
upon  the  intensity  of  the  light  and  dura- 
tion of  exposure.  If  any  opaque  or  trans- 
lucent object  be  laid  upon  a  sheet  of  pa- 
per so  prepared,  so  as  wholly  or  partially 
to  intercept  the  incident  light,  a  represen- 
tation of  the  object  is  obtained  upon  the 


454 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PHO 


paper.  "Where  the  light  has  been  wholly 
intercepted,  it  remains  white  ;  where  par- 
tially so,  various  shades  are  produced ; 
and  wherever  the  light  has  fallen  without 
interruption,  the  utmost  blackness  is  ob- 
tained. If,  for  instance,  a  portrait  paint- 
ed in  transparent  colors  upon  a  plate  of 
glass  be  laid  upon  a  piece  of  the  prepared 
paper,  and  exposed  to  the  solar  light,  a 
copy  is  obtained  in  which  the  lights  of  the 
original  are  shades,  and  the  shades  lights 
in  proportion  to  their  intensity  ;  but  if 
such  a  picture  be  taken  upon  a  very  thin 
piece  ot  paper,  this  may  be  again  copied 
by  a  repetition  of  the  process,  and  then 
the  lights  and  shades  will  be  as  in  the  ori- 
ginal. It  is,  however,  obvious  that  such 
a  photograph  will  only  be  durable  whilst 
kept  in  the  dark,  and  that  exposure  to 
lignt  will  gradually  obliterate  the  whole ; 
to  fix  it,  the  paper  must  be  washed  in  a 
solution  of  hyposulphite  of  lime  or  of  so- 
da, which  removes  all  remaining  and  un- 
altered salt  of  silver,  but  leaves  the  image 
untouched.  In  this  process  the  paper, 
after  having  been  impregnated  with  ni- 
trate of  silver,  or  with  ammonia-nitrate  of 
silver,  is  generally  dipped  in  a  solution  of 
common-salt,  by  which  chloride  of  silver 
is  formed,  and  this  is  more  susceptible  of 
the  influence  of  light  than  the  mere  ni- 
trate. 

Various  salts  of  silver  have  been  used 
by  different  operators,  and  the  processes 
have  received  different  names  :  those  of 
Mr.  Talbot  and  Sir.  J.  Herschel  are  the 
most  approved.  The  invention  was  first 
made  public  by  M.  Arago.  Mr.  Hunt's 
process  called  chromatype  is  given  under 
that  article,  and  under  the  head  calotype  is 
given  Mr.  F.  Talbot's  process. 

The  Cyanotype  of  Sir  J.  Herschel  is 
made  by  washing  the  paper  with  a  solu- 
tion of  ammonio  citrate  of  iron.  It  is 
then  exposed  to  light,  and  a  latent  picture 
impressed  on  it.  If  the  paper  be  sensibly 
darkened,  the  picture  will  appear  nega- 
tive. It  is  now  touched  over  sparingly 
and  equally  with  a  solution  of  ferro-cya- 
nide  of  potassium  in  which  is  dissolved  a 
little  gum.  The  negative  picture  vanish- 
es and  is  replaced  by  a  positive  one  of  a 
violet  blue  on  a  green  ground  ;  a  second 
washing  brings  out  the  picture  clearer. 

A  second  process  of  the  cyanotype  is, 
to  saturate  the  paper  with  a  solution  of 
equal  parts  of  ammonio  citrate  of  iron  and 
ferro-sesquicyanide  of  potassium.  When 
a  picture  lias  been  impressed  it  is  thrown 
into  water  and  then  dried,  and  a  negative 
picture  results.  When  this  is  washed  with 
solution  of  proto-nitrate  of  mercury  it  is 


discharged,  but  may  be  restored  by  wash- 
ing  out  the  nitrate  and  drying  the  paper. 
A  smooth  hot  iron  is  now  passed  over  it, 
and  the  obliterated  picture  comes  out  of  a 
brown  tint  •  these  photographs  fade,  but 
are  restored  by  heat. 

Third  process  :  1  pint  of  ammonio-ci- 
trate  of  iron  is  dissolved  in  11  parts  of 
water,  and  this  is  mixed  with  an  equal 
quantity  of  a  cold,  saturated  solution,  of 
bichloride  of  mercury,  before  the  precipi- 
tate is  formed :  the  solution  is  brushed 
over  paper,  which  should  have  a  tint  ot 
yellow.  This  paper  keeps  well :  when  a 
picture  is  formed  on  it,  it  is  washed  over 
with  a  saturated  solution  of  prnssiatc  of 
potash,  diluted  with  thin  gum  water.  The 
picture  is  fixed  by  drying,  and  are  beauti- 
ful positive  ones. 

Another  process  of  Herschel's  is,  to  mix 
solution  of  nitrate  silver  of  sp.  gr.  1-200, 
with  ferro-tartaric  acid  solution  sp.  gr. 
1-023,  till  a  precipitate  falls  which  is  re- 
dissolved  by  heat,  leaving  a  black  sedi- 
ment and  a  pale  yellow  liquor.  This  li- 
quor undergoes  no  further  alteration. 
This  is  spread  on  paper  and  exposed  wet 
to  sunshine  for  a  few  seconds,  when  it 
may  be  withdrawn.  The  image  gradual- 
ly comes  out  afterwards,  and  is  very  in- 
tense. If  dried  before  exposure  in  the 
camera,  an  invisible  image  is  formed, 
which,  on  breathing  upon,  immediately 
appears,  and,  as  if  by  magic,  acquires 
great  sharpness  :  instead  of  breathing 
upon  it,  it  may  be  laid  between  the  folds 
of  wet  paper. 

■  Amphitype. — So  called  because  both  po- 
sitive and  negative  pictures  are  produced 
by  it,  is  another  process  of  Sir  J.  Hers- 
chell's.  The  paper  must  be  prepared  with 
ferro-tartrate  of  mercury  or  lead,  or  ferro- 
citrates  of  the  same  bases.  The  salts 
should  be  laid  on  in  the  state  of  cream  : 
or,  the  paper  may  be  saturated  with  ni- 
trates of  the  oxides  and  then  dipped  in 
ammonio-citrate  or  tartrate  of  iron.  Ne- 
gative pictures  are  obtained  by  long  ex- 
posure, which  are  not  permanent.  When 
faded,  it  may  be  restored  by  dipping  it 
in  a  solution  "of  pernitrate  of  mercury  till 
the  original  picture  disappears,  (this  also 
requires  a  long  time,)  it  is  then  well 
washed  with  water  and  dried,  rubbed 
over  with  a  hot  iron  between  clean  papers 
when  a  black  positive  picture  at  once  ap- 
pears. If  the  paper  had  been  previously 
washed  with  uric  acid  the  pictures  pro- 
duced are  much  better. 

The  juices  of  flowers  have  been  found 
to  be  very  sensibly  effected  by  light  and 
to  produce  images  by  long  exposure  in 


PHO] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


455 


the  camera :  this  process  is  called  antlw- 

The  following  are  correct  directions  for 
preparing  Talbotype  paper : 

Iodizing. — 100  grains  nitrate  of  silver 
dissolved  in  3  oz.  distilled  water ;  wash 
the  paper  evenly  with  a  brush  or  clean 
cotton  ;  spread  the  paper  on  sheets  of 
blotting  paper,  till  quite  dry.  Then  im- 
merse it  in  a  bath  ot  iodide  of  potassium 
1  oz.  and  a  pint  of  water,  leave  it  a  very 
few  seconds,  not  more  than  twenty ;  then 
immerse  it  in  distilled  water  for  some 
minutes,  and  afterwards  pin  up  by  a  cor- 
ner and  dry ;  lastly,  pin  it  up  in  the  sun 
for  at  least  an  hour. 

Preparing  for  Camera. — Wash  with  1 
part  nitrate  silver  (proportion  50  grains 
to  an  ounce  water) :  6  parts  of  saturated 
solution  of  gallic  acid,  2  parts  acetic  acid ; 
take  off  superfluous  moisture  with  clean 
white  blotting  paper. 

To  bring  out  Picture. — 1  part  nitrate 
silver  (50  grains  to  an  ounce,)  3  parts  sa- 
turated solution  gallic  acid ;  when  finish- 
ed wash  in  three  clean  waters  ;  and  to  fix 
temporarily,  wash  with  bromide  of  potas- 
sium ;  proportion  of  solution  10  grains  to 
1  oz.  distilled  water ;  after  some  minutes 
wash  and  dry. 

For  final  Fixing. — Immerse  in  hot  bath 
of  1  part  of  a  saturated  solution  of  hy- 
posulphite of  soda,  to  10  parts  water  ;  a 
couple  of  minutes  will  bring  out  the  io- 
dine ;  lastly,  wash  with  three  different 
hot  waters,  two  or  three  minutes  in  each. 

Copying  Paper. — 18  grains  salt,  dissolv- 
ed in  1  pint  distilled  water ;  soak  the  pa- 
per in  a  bath  of  this  and  dry ;  then  take  30 
grains  nitrate  silver  in  1  ounce  distilled 
water ;  add  enough  strong  ammonia  to 
make  it  turbid,  then  clear  it  by  adding 
more  ammonia  ;  with  this  solution  wash 
your  paper  with  a  brush,  when  dry  it  is 
fit  for  the  copying  press. 

To  Fix. — 10  grains  hyposulphite  soda, 
1  ounce  distilled  water ;  lay  the  copies  in 
a  bath  of  this  after  immersing  them  in  3 
baths  of  warm  water  ;  and  after  the  hy- 
posulphite immerse  them  in  three  waters 
and  then  dry. 

Chrysotype. — Paper  is  washed  with  a 
solution  ot  ammonio  citrate  of  iron  and 
dried ;  the  paper  should  then  be  of  a  yel- 
low color,  (not  brown,)  and  it  is  fit  to 
take  an  image,  which,  when  produced,  is 
faint  and  hardly  perceptible  ;  on  removal 
from  the  camera,  it  is  washed  over  with 
a  solution  of  chloride  of  gold  when  the 

Sieture  is  produced,  which   afterwards 
arkens.    It  is  then  well  rinsed  with  wa- 


ter and  washed  over  with  a  weak  solution 
of  hydriodate  of  potass. 

Energiatype. — A  process  of  Mr.  Hunt. — 
Good  letter-paper  is  washed  over  with  a 
solution  of  succinic  acid  5  grains,  5  grains 
common  salt,  and  half  a  dram  of  mucilage 
in  1  oz.  of  water :  when  dry,  the  paper  is 
drawn  over  the  surface  of  60  grains  of  ni- 
trate of  silver  in  1  oz.  distilled  water. 
The  paper  is  dried  in  the  dark  and  fitted 
for  use.  It  is  white,  of  a  permanent  co- 
lor ;  2  or  3  minutes  is  sufficient  to  take  a 
portrait.  The  picture  is  brought  out  by 
passing  the  paper  over  a  strong  solution 
of  proto-sulphate  of  iron  thickened  by 
gum.  The  paper  is  then  well  washed 
with  water,  and  may  be  further  fastened  by 
weak  ammonia  or  hyposulphite  of  sodu. 

Messrs.  Langenheim,  of  Philadelphia, 
have  discovered,  the  art  of  making  photo- 
graphic pictures  on  glass,  such  as  por- 
traits, landscape  views,  copies  of  daguer- 
reotypes, which  is  exactly  similar  to  that 
described  by  M.  Kegnault,  in  behalf  of  M. 
Evrard,  of  Lille,  who  is  said  to  have  dis- 
covered it  in  1847.  The  principle  of  the 
discovery  is  a  matrix  of  albumen,  render- 
ed sensible  to  the  action  of  light,  by  ace- 
to-nitrate  of  silver,  and  spread  in  a  thin 
layer  on  a  plate  of  glass.  The  process  is 
to  take  a  certain  number  of  the  white  of 
eggs,  and  remove  all  the  non-transparent 
part,  and  then  add  a  few  drops  or  a  sa- 
turated solution  of  iodide  of  potassium, 
then  beat  the  eggs  into  froth  and  allow  it 
to  settle.  The  plate  of  glass  is  well  clean- 
ed with  alcohol,  and  the  albumen  is  then 
spread  over  the  glass  in  a  thin  layer  with 
another  piece  of  glass.  The  glass  must 
have  a  perfect  thin  coat  adhering  to  it, 
when  it  is  hung  up  by  one  of  the  corners 
to  drain  off  the  excess.  The  glass  is  then 
placed  flat  upon  a  level  board,  screened 
trom  dust  and  allowed  to  dry.  When 
dry  it  is  submitted  to  a  good  heat,  but 
not  so  much  that  the  albumen  will  peel 
off.  After  this  the  glass  is  dipped  into 
a  solution  of  aceto-nitrate  of  silver,  face 
downwards,  after  which  it  is  removed 
and  immersed  in  a  basin  of  clean  water, 
being  stirred  in  it,  for  a  few  seconds,  then 
taken  out,  held  up  by  a  corner,  and  is 
completely  sensitive,  moist  or  dry,  to  re- 
ceive photographic  impressions.  It  is 
then  placed  in  the  camera  obscura,  after 
which  it  is  dipped  in  a  bath  of  gallic  acid, 
to  which  is  added  a  little  of  aceto-nitrate 
of  silver.  Care  is  taken  not  to  let  the 
glass  remain  too  long  in  this.  After  be- 
ing dipped  in  the  gallic  acid  it  is  washed 
in  water  and  then  immersed  in  a  solution 


456 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PHO 


of  the  bromide  of  potassium  (20  parts  to 
100  of  water),  after  which  it  is  carefully 
and  well  washed  in  water,  and  left  to 
drv  in  a  horizontal  position  in  a  dark  room. 
PHOTOMETER.  An  instrument  for 
measuring  the  intensity  of  light,  or  of 
illumination. 

The  one  which  most  usually  goes 
under  this  name  is  the  photometer  in- 
by  the  late  Sir  John  Leslie.  It 
is  merely  the  differential 
thermometer  of  the  same 
ingenious  philosopher, 
having  one  of  its  balls 
diaphanous,  and  the 
other  coated  with  China 
ink,  or  blown  of  deep 
black  enamel ;  and  the 
whole  covered  by  a  case 
of  thin  transparent  glass,  to  defend  the 
balls  from  the  disturbing  influence  of 
currents  of  air.  The  photometer  has  two 
general  forms;  the  one  portable  (fig.  1;, 
in  which  the  black  ball  is  about  an  inch 
higher  than  the  other,  and  bent  forward 
to  the  same  vertical  line,  or  the  axis  of 
the  translucent  cylindrical  case;  and  the 
other  stationary  ("fig.  2),  having  both  its 
balls  of  the  same  height,  and  reclining  in 
opposite  ways  :  the  case  being  composed 
of  a  wide  cylinder  surmounted  by  the 
larger  segment  of  a  hollow  glass  sphere. 
The  latter  form  of  the  instrument,  though 
less  commodious,  is  better  adapted  for 
nice  observations ;  since,  besides  receiv- 
ing the  light  more  regularly,  its  balls, 
from  being  on  the  same  level,  are  not 
liable  to  be  any  how  disturbed  in  their 
indications  by  different  strata  of  unequal- 
ly heated  air. 

The  theory  of  this  photometer  de- 
pends on  the  assumed  principle  that  the 
intensity  of  light  is  proportional  to  the 
heat  excited  by  its  incidence  on  the 
black  ball.  When  the  instrument  is  ex- 
posed to  light,  the  rays  which  fall  on  the 
clear  ball  pass  through  it  without  suffer- 
ing obstruction  ;  but  those  which  strike 
the  dark  ball  are  stopped  and  absorbed 
at  its  surface,  where,  assuming  a  latent 
form,  they  act  as  heat,  which,  by  ex- 
panding the  air  within  the  ball,  causes  the 
liquid  in  the  stem  to  descend.  This 
heat  will  continue  to  accumulate  till  its 
farther  increase  comes  to  be  counter- 
acted by  an  opposite  dispersion,  caused 
by  the  rise  of  temperature  which  the 
ball  has  acquired.  But,  in  still  air,  the 
rate  of  cooling  is,  within  moderate  limits, 
proportional  to  the  excess  of  the  temper- 
ature of  a  given  surface  above  that 
of  the  surrounding  medium.    Hence  the 


space  through  which  the  colored  liquid 
smks  in  the  stem  will  measure  the  mo- 
mentary impressions  of  light,  or  its 
actual  intensity. 

The  graduation  is  entirely  arbitrary,  and 
may  be  regulated  according  to  faucy  or 
convenience.  Leslie  adopted  the  same 
scale  of  divisions  as  in  the  different  ther- 
mometer, ten  degrees  of  which  corres- 
pond to  one  of  the  centigrade  thermo- 
meter. When  the  temperature  of  both 
balls  is  exactly  the  same,  that  is,  when 
the  instrument  is  excluded  from  light, 
the  liquid  in  the  stem  next  the  colored 
ball  stands  at  zero.  In  England  the 
direct  impression  of  the  sun  at  noon, 
about  the  summer  solstice,  forces  the  li- 
quid down  to  90°  or  100°.  The  greatest 
force  of  the  solar  beams,  in  the  depth  of 
winter,  measure  only  about  25°.  At 
the  altitude  of  3°  above  the  horizon,  the 
whole  effect  of  the  sun's  rays  does  not  ex- 
ceed one  degree.  The  indirect  light  of 
the  sky  at  noon  in  the  summer  is  from 
30°  to  40° ;  in  winter  from  10°  to  15°. 
Comparing  the  illuminating  power  of  the 
solar  rays  with  that  of  artificial  lights, 
Leslie  found  the  light  emitted  by  the  sun 
12,000  times  more  powerful  than  that  of 
a  wax  candle ;  that  is  to  say,  if  a  portion 
of  the  luminous  solar  matter,  rather  less 
than  half  an  inch  in  diameter,  were  trans- 
mitted to  our  planet,  it  would  throw 
forth  a  light  equal  to  the  effect  of  12,000 
candles. 

A  great  objection  to  this  instrument 
is,  that  the  same  quantity  of  light  emitted 
by  terrestrial  bodies  of  different  kinds  is 
not  always  accompanied  with  the  same 
degree  of  heat.  Thus,  phosphorus  burns 
in  oxygen  gas  with  intense  splendor, 
and  yet  gives  out  far  less  heat  than 
the  comparatively  dull  combustion  of 
hydrogen  in  the  same  gas ;  and  the  pho- 
tometer is  more  affected  by  a  fire  so  dull 
that  not  a  single  letter  could  be  discerned 
in  a  well-printed  page,  than  by  the  de- 
gree of  daylight  by  which  the  same  page 
could  be  read  with  pleasure  and  facility. 
PHOTOMETRY.  The  science  which 
treats  of  the  measurement  of  light.  At- 
tempts to  determine  the  relative  inten- 
sities of  different  lights  were  made  at  an 
early  period  in  the  nistory  of  experimen- 
tal science.  For  the  purpose  ot  compar- 
ing the  light  of  Sirius  with  that  of  the 
sun,  the  celebrated  Huygens  employed 
a  tube  having  a  very  small  aperture  at 
one  end,  into  which  was  inserted  a 
minute  globular  lens,  which  allowed  only 
the  27664th  part  of  the  solar  disc  to  be 
seen,  and  this  small  portion  afforded  a 


pia] 


CYCLOPEDIA    OF    TFIE    USEFUL    ARTS. 


457 


light  which  appeared  equally  bright  with 
Sirius;  whence  he  concluded  the  dis- 
tance of  Sirius  to  be  27664  times  greater 
than  that  of  the  sun.  Celsius  appears  to 
have  been  the  first  who  proposed  to  mea- 
sure light  directly  by  means  of  what 
he  called  a  lucimeter.  His  method,  how- 
ever, which  was  an  extremely  imperfect 
one,  consisted  simply  in  observing  the 
greatest  distance  from  the  eye  at  which 
small  circles  painted  on  paper  were  dis- 
tinctly visible  in  different  lights.  It  was 
reserved  for  Bouguer  to  establish  pho- 
tomery  on  true  principles.  Having  been 
induced  by  Mairan's  remarks  on  the  re- 
lative proportion  of  the  sun's  light  at  the 
summer  and  winter  solstice  to  investigate 
the  experiment,  he  undertook  a  series  of 
experiments. 

Lambert  afterwards  treated  the  subject 
more  generally,  and  with  great  mathema- 
tical elegance.  The  principle  adopted  by 
Bouguer  and  Lambert  is  extremely  simple. 
Though  the  eye  cannot  judge  of  the  pro- 
portional force  of  different'  lights,  it  can 
distinguish  in  many  cases  with  great  pre- 
cision when  two  similar  surfaces  presented 
together  are  equally  illuminated,  or  when 
the  shadows  of  an  opaque  object  thrown 
upon  them  by  different  lights  are  equally 
dark.  But,  as  the  particles  of  light  proceed 
in  straight  lines,  they  must  spread  uni- 
formly, and  hence  their  density  will  di- 
minish in  the  duplicate  ratio  of  their 
distances.  From  the  respective  situa- 
tions, therefore,  of  the  centres  of  diverg- 
ency when  the  contrasted  surfaces  be- 
come equally  bright,  we  may  easily 
compute  their  relative  degrees  of  illu- 
mination. The  objection  to  this  method 
is,  that  the  apparatus  admits  of  no  certain 
standard  of  comparison.  Even  the  light 
of  the  sun  itself,  at  the  same  altitude, 
and  in  the  same  climate,  is  subject  to 
considerable  variation ;  much  more  so 
any  artificial  light,  the  force  of  which 
must  always  be  influenced  by  a  number 
of  indefinable  circumstances.  In  this  re- 
spect, therefore,  the  photometer  describ- 
ed in  the  preceding  article  has  a  great 
and  decided  advantage. 

A  simple  and  elegant  application  of  the 
principle  of  Bouguer  was  made  by  the 
late  Dr.  Ritchie,  of  London.  His  appa- 
ratus consists  of  a  rectangular  box, 
about  an  inch  and  a  half  or  two  inches 
square,  open  at  both  ends  and  blackened 
within,  to  absorb  extraneous  light.  With- 
in, inclined  at  angles  of  45°  to  its  axis, 
are  placed  two  rectangular  plates  of  plane 
looking-glass,  cut  from  one  and  the  same 
strip,  to  insure  equality  of  their  refleet- 
20 


I  ing  powers,  and  fastened  so  as  to  meet 
j  at  the  top,  in  the  middle  of  a  narrow  slit 
i  about  an  inch  long,  and  an  eighth  of  an 
inch  broad,  which  is  covered  with  a  slip 
of  fine  tissue  or  oiled  paper.  In  compar- 
ing, by  means  of  this  instrument,  the  il- 
luminating powers  of  two  different 
sources  of  light,  they  must  be  placed 
at  such  a  distance  from  each  other,  and 
from  the  instrument  between  them,  that 
the  light  of  every  part  of  each  shall  fall 
on  the  reflector  next  it,  and  be  reflected 
to  the  corresponding  portion  of  the  oil- 
ed paper.  The  instrument  is  then  moved 
nearer  the  one  or  the  other,  till  the  two 
portions  of  the  paper  corresponding  to 
the  respective  mirrors  are  equally  illu- 
minated, of  which  the  eye  can  judge  with 
considerable  certainty. 

The  modification  of  this  method, 
which  consists  in  contrasting  the  sha- 
dows of  an  opaque  object  formed  by  dif- 
ferent lights,  is  usually  ascribed  to 
Count  Rumford,  by  whom  it  was  pro- 
posed, butwa3  long  before  used  by  Lam- 
bert. It  is  generally  supposed  that  the 
equality  of  two  shadows  can  be  appreci- 
ated with  more  certainty  than  that  of  two 
lights  ;  but,  when  the  lights  are  of  differ- 
ent colors,  their  estimation  by  either  me- 
thod admits  of  little  precision. 

M.  Arago  has  proposed  a  method  of 
determining  the  relative  intensities  of 
different  lights  entirely  different  in  prin- 
ciple from  any  of  the  preceding,  and  pro- 
bably susceptible  of  much  greater  accu- 
racy. It  is  founded  on  the  properties  of 
polarized  light.  When  two  lights  are  to 
be  compared,  the  rays  from  each  are 
polarized  by  causing  them  to  pass  through 
a  plate  of  tourmaline  cut  parallel  to  the 
axis,  or  by  reflecting  them  from  a  plate 
of  glass,  on  which  they  fall  at  the  polar- 
izing angle.  They  are  then  received  on 
a  plate  of  rock-crystal,  cut  perpendicu- 
larly to  the  axis,  and  observed  through  a 
doubly  refracting  prism.  Each  light  will 
thus  give  two  images  tinged  with  the 
complementary  colors.  The  images  are 
then  brought  into  such  a  position  that 
the  red  of  the  one  falls  over  the  green  of 
the  other.  If  the  two  lights  are  equal  in 
intensity,  this  superposition  will  produce 
a  white  image;  if  unequal,  the  image 
will  be  slightly  colored  with  red  or  green, 
according  as  the  one  or  the  other  pre- 
dominates. The  apparatus  which  this 
method  requires  is  somewhat  complicat- 
j  ed,  and  its  manipulation  must  be  attend- 
I  ed  with  considerable  trouble. 

PIANO-FORTE.    A  musical  stringed 
I  instrument  of  the  keyed  species.      Ita 


458 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pic 


name,  compounded  of  two  Italian  words, 
signifying  soft  and  loud,  was  probably 
given  to  it  to  distinguish  it  from  the 
harpsichord  and  spinet,  in  which  no  light- 
ness of  touch  could  lessen  the  strength  of 
the  sound  produced  from  the  quills  al- 
ways striking  the  strings  with  equal 
force ;  whereas,  in  the  piano-forte,  the 
strings  are  put  in  vibration  by  means  of 
small' hammers,  connected  by  levers  with 
the  key  or  finger  board,  which  hammers 
quit  the  string  the  moment  it  is  struck,  a 
damper  falling  down  upon  it  the  moment 
the  finger  quits  the  key.  The  invention 
of  the  piano- forte  is  ascribed  to  a  German 
named  Schroeder,  who  lived  at  the  begin- 
ning of  last  century  ;  but  it  was  first  in- 
troduced into  England  in  1766,  by  Zumpe, 
by  whom  it  was  greatly  improved.  With- 
in the  present  century  this  instrument 
has  received  many  useful  and  valuable 
improvements,  at  the  hands  of  manu- 
facturers, in  this  country  and  Europe: 
Pianos  made  in  this  country  preserve 
their  tone  better,  and  even  in  London  a 
Chickering  make  is  often  preferred  to  a 
Collard  or  Errard.  Many  distinguished 
musicians  have  devoted  themselves  to  the 
composition  of  pieces  for  this  instrument ; 
and  several  of  the  most  distinguished 
composers  in  modern  times,  among  whom 
we  may  mention  Hummel,  Czerny,  Herz, 
Kalkbrenner,  Cramer,  Moscheles,  Chopin, 
Thalberg,  Liszt,  &c,  have  made  the  in- 
strument itself  almost  their  exclusive 
study.  It  is  variously  formed,  and  is 
designated  grand  square,  semi-grand, 
cabinet,  cottage,  and  piccolo.  Some  piano- 
fortes have  7  octaves,  but  the  usual  num- 
ber in  the  best  instrument  is  6i.  In 
others  6  or  5t. 

One  of  the  recent  improvements  of  this 
instrument,  is  that  entitled,  "the  patent 
dolce  campano  pedal  piano-forte,"  man- 
ufactured by  Messrs.  Boardman  &  Gray, 
of  N.Y.  The  effects  produced  by  the  ap- 
plication of  this  pedal  are  prolongation 
of  the  sound,  and  the  alteration  of  the 
quality  of  tone  from  the  common  piano, 
to  that  of  sweet  bells  or  harps,  and  which 
can  be  used  ad  libitum  by  the  performer, 
thereby  producing  not  only  a  charming 
variety  of  sound,  but  a  most  beautiful 
accompaniment  long  sought  for  the  voice. 
The  mechanical  part  of  this  improvement 
is  simple,  being  merely  a  number  of 
weights,  arranged  by  a  lever  pedal  to  fall 
when  required  upon  an  equal  number  of 
screws,  fixed  in  the  sounding  board  of  a 
piano,  and  which  of  course  "altering  the 
vibration,  effects  peculiar  qualities  and 
expressions  of  tone,  which,  when  com- 


bined with  the  other  two  pedals,  produces 
the  lightest  shade  of  altissimo  notes,  alter- 
nating with  crescendo  and  diminuendo, 
and  other  musical  accents,  in  imitation  of 
an  orchestral  performance.  Its  great  ad- 
vantage are  clearness,  brilliancy,  and 
delicacy  of  tone,  which  falls  on  the  ear 
like  the  chimes  of  distant  bells,  hence  its 
name  "  Dolce  Campano."  The  attach- 
ment is  simple,  and  may  be  detached  in 
a  few  minutes.  The  JEolian  is  another 
attachment  put  on  pianos,  which  appears 
to  some  to  produce  an  agreeable  har- 
mony. 

PIAZZA.  In  architecture,  a  square 
open  space  surrounded  by  buildings. 
Improperly  used  in  England  to  denote  a 
walk  under  an  arcade. 

PICA.  In  printing,  a  type  of  a  moder- 
ate size  ;  so  called  because  it  was  used  in 
printing  the  Pic,  the  service-book  of  old 
Catholic  times,  which  again  is  supposed 
to  derive  its  appellation  from  the piccolor 
of  the  text  and  rubric. 

PICAMAR.  The  bitter  principle  of 
tar  ;  whence  it  derives  its  name. 

PICKET.  In  fortification,  a  stake  used 
in  laying  out  ground  to  mark  the  bounds 
and  angles.  Pickets  are  of  various  lengths, 
according  to  the  purpose  they  are  to 
serve.  One  end  is  sharp  and  shod  with 
iron,  and  the  other  sometimes  carries  a 
small  flag,  for  the  purpose  of  rendering 
it  visible  at  a  distance. 

PICKLES  are  various  kinds  of  vege- 
tables and  fruits  preserved  in  vinegar. 
The  substances  are  first  well  cleaned  with 
water,  then  steeped  for  some  time  in 
brine,  and  afterward  transferred  to 
bottles,  which  are  filled  up  with  good 
vinegar.  Certain  fruits,  like  walnuts,  re- 
quire to  be  pickled  with  scalding-hot 
vinegar;  others,  as  red  cabbage,  with 
cold  vinegar ;  but  onions,  to  preserve 
their  whiteness,  with  distilled  vinegar. 
Wood  vinegar  is  never  used  by  the  prin- 
cipal pickle  manufacturers,  but  the  best 
malt  or  white-wine  vinegar,  No.  22  or  24. 
Kitchener  says,  that  by  parboiling  the 
pickles  in  brine,  they  will  be  ready  in 
half  the  time  of  what  they  require  when 
done  cold.  Cabbage,  however,  cauli- 
flowers, and  such  articles,  would  thereby 
become  flabby,  and  lose  that  crispness 
which  many  people  relish.  When  re- 
moved from  the  brine,  they  should  be 
cooled,  drained,  and  even  dried,  before 
being  put  into  the  vinegar.  To  assist  the 
preservation  of  pickles,  a  portion  of  salt 
is  often  added,  and  likewise,  to  give 
flavor,  various  spices,  such  as  long  pepper, 
black    pepper,  white   pepper,    allspice, 


pig] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


459 


finger,  cloves,  mace,  garlic,  mustard, 
orseradish,  shallots,  capsicum.  When 
the  spices  are  bruised,  they  are  most  effi- 
caceous,  but  they  are  apt  to  render  the 
pickle  turbid  and  discolored.  The  flavor- 
ing ingredients  of  Indian  pickle  are  Curry 
powder  mixed  with  a  large  proportion  of 
mustard  and  garlic.  Green  peaches  are 
said  to  make  the  best  imitation  of  the 
Indian  mango. 

PICROMEL.  A  peculiar  substance 
of  a  sweetish  bitter  taste,  which  exists  in 
bile. 

PICROTOXIA.  A  poisonous  bitter 
principle,  which  exists  in  the  Cocculus 
nulicus. 

PIER.  In  architecture,  the  solid  be- 
tween the  openings  of  a  building,  or  that 
from  which  an  arch  springs.  An  abut- 
ment pier,  in  a  bridge,  is  that  next  the 
shore.  For  the  mode  of  building  the 
piers  of  a  bridge,  see  Bridge. 

Pier.  In  engineering,  identical  with 
moat,  and  is  used  to  designate  the  masses 
of  building  erected  to  form  harbors, 
landing-places,  &c. 

PIGS.  The  want  of  ready  and  cheap 
access  to  foreign  markets,  led  the  western 
farmers  to  raising  hogs  and  distilling 
whiskey  as  a  convenient  means  of  taking 
corn,  the  great  staple,  in  these  shapes  to 
market.  Mr  Cist,  ot  Ohio,  in  a  communica- 
tion published  in  the  patent  office  report 
for  1847,  from  which  this  article  is  con- 
densed, shows  how  small  a  proportion  of 
the  corn  crop  finds  its  way  into  the 
market  as  meal  or  grain. 

The  corn  raised  in  reference  to  the 
whiskey  market  is  independent  of  that 
which  is  fed  to  hogs,  no  price  that  can 
be  paid  by  the  distillers  affording  ade- 
quate remuneration  to  growers  of  corn 
who  have  to  transport  it  far  by  land  car- 
riage. 

Cincinnati  being  the  business  centre  of 
an  immense  corn  growing  and  hog  rais- 
ing region,  is  in  fact  the  principal  pork 
market  in  the  United  States,  and  without 
even  the  exceptions  of  Cork  or  Belfast, 
Ireland,  the  largest  in  the  world. 

The  business  of  putting  up  pork  here 
for  distant  markets,  is  of  some  twenty- 
six  years'  standing,  but  it  is  only  since 
1833,  that  it  has  sprung  into  much  im- 
portance. 

The  following  table  furnishes  a  list  of 
hogs  put  up  each  year  since  1840,  and 
the  prices  at  which  the  market  opened. 
The  season  begins  in  November  and 
ends  in  March.  Each  year  refers  to  that 
in  which  business  closed. 


Year. 

No.  of  Hogs. 

Price. 

1840 

95,000 

03  00  to  3  50 

1841 

160,000 

3  50  ;i  3  75 

1842 

220.000 

2  00  "  2  50 

1843 

250,000 

1  62  "  2  00 

1844 

240,000 

2  25  "  2  65 

1845 

213,000 

2  50  "  2  70 

1846 

287.000 

4  00  *'  4  25 

1847 

250,000 

2  70  "  2  80 

The  hogs  packed  in  Ohio  in 

1844  were 560,000 

1845  "     450.000 

1846  "     425,000 

1847  "     325,000 

Of  which  aggregate  Cincinnati  packed 
in 

1844 43  per  cent. 

1845 47       " 

1846 68        " 

1847 70        " 

The  entire  packing  of  the  west  for 
three  years  may  be  divided  as  follows  : 


1844. 

1845. 

1846. 

Missouri 

Tennessee 

Kentucky 

16,000 
16,000 
91,000 
136,709 
257,414 
560,748 
1,200 

31,700 
1,500 
83,800 
67,964 
147,420 
445,538 
8,850 

70.898 

42,975 

215,125 

68.120 

251,236 

Ohio 

420,833 

Minor  Points.... 

18,675 

The  hogs  raised  for  this  market  are 
generally  a  cross  of  Irish  Grazier,  By  field, 
Berkshire,  Russia,  and  China,  in  such 
proportions  as  to  unite  the  qualifications 
of  size,  tendency  to  fat  and  beauty  of 
shape  to  the  hams.  They  are  driven  in 
at  the  age  of  from  eleven  to  eighteen 
months  old,  in  general,  although  a  few 
reach  greater  ages.  The  hogs  run  in  the 
woods  until  within  five  or  six  weeks  of 
killing  time,  when  they  are  turned  into 
the  corn  fields  to  fatten.  If  the  acorns 
and  beach-nuts  are  abundant,  ihey  re- 
quire less  corn,  but  the  flesh  and  fat, 
although  hardened  by  the  corn,  is  not  as 
firm  as  when  they  are  turned  into  the 
corn  fields  in  a  less  thriving  condition, 
during  years  when  mast  as  it  is  called  is 
less  abundant. 

From  the  8th  to  the  10th  of  November 
the  pork  season  begins,  and  the  hogs  are 
sold  by  the  farmers  direct  to  the  packers, 
when  the  quantity  they  own  justifies  it. 
Some  of  these  farmers  drive  in  one  sea- 
son as  high  as  one  thousand  head  of 


460 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PIQ 


hogs  into  their  fields.  The  hogs  are 
driven  into  pens  adjacent  to  the  respec- 
tive slaughter  houses.  As  soon  as  the 
drover  or  farmer  sells  to  the  packer,  the 
hogs  are  put  into  small  pens,  where  they 
are  crowded  as  thick  as  they  can  stand, 
and  a  hand  walks  over  the  drove  knock- 
ing them  on  the  head  successively,  with 
a  two  pointed  hammer  adapted  to  the 

Eurpose.  They  are  then  dragged  out  by 
ooks  into  the  sticking  room,  where 
their  throats  are  cut,  the  blood  passing 
through  a  drain  or  sewer  below  into  large 
tanks  prepared  to  receive  it.  The  blood 
is  saved  to  be  sold  together  with  the 
hoofs  and  hair,  to  the  manufacturers  of 
prussiate  of  potash  and  prussian  blue. 
Adjacent  to  the  sticking  room  are  the 
scalding  troughs,  which  are  heated  by 
steam.  These  troughs  are  of  one  thou- 
sand gallons  capacity  each.  After  being 
scalded,  the  hogs  are  tossed  by  machin- 
ery on  to  a  long  bench,  as  many  persons 
getting  to  work  on  a  hog  as  can  get  round 
it.  One  cleans  out  the  ear,  which  work 
must  be  done  while  the  hog  is  reeking 
with  steam,  others  pull  off  the  bristles 
and  hair,  which  are  thrown  on  the  floor, 
others  again  scrape  the  animal.  When 
these  operations  are  through,  his  hind 
legs  are  stretched  open  with  a  stick  called 
a  gambril,  and  the  hog  is  borne  off  by 
three  men,  two  of  whom  carry  the  front 
part  on  their  crossed  hands,  and  the 
other  seizes  the  gambril,  by  which  he 
carries  to  the  proper  place,  and  slings  tho 
hog  to  a  hook  which  suspends  him  from 
the  floor.  Here  the  animal  falls  into  the 
hands  of  the  gutter,  who  tears  out  the 
insides,  stripping  at  the  rate  of  three 
hogs  to  the  minute.  The  slaughter  houses 
of  Cincinnati  are  in  the  outskirts  of  the 
city,  are  ten  in  number,  and  fifty  by  one 
hundred  and  thirty  feet  each  in  extent — 
the  frames  being  boarded  up  with  mova- 
ble lattice  work  at  the  sides,  which  is 
kept  open  to  admit  air  in  the  ordinary 
temperature,  but  is  shut  up  during  the 
intense  cold  which  occasionally  attends 
the  packing  season,  so  that  hogs  shall 
not  be  frozen  so  stiff  that  they  cannot  be 
cut  up  to  advantage. 

The  slaughterers  formerly  got  the  gut 
fat  for  the  whole  of  the  labor  thus  de- 
scribed, wagoning  the  hogs  more  than  a 
mile  to  the  pork  houses  free  of  expense 
to  the  owners.  Every  year,  however, 
enhances  the  value  of  the  perquisites, 
such  as  the  fat,  heart,  liver,  &c,  for 
food,  and  the  hoofs,  hair,  &c,  for  manu- 
facturing purposes.  For  the  last  two 
years,  from  ten  to  twenty-five  cents  per 


hog  have  been  paid  as  a  bonus  for  the 
privilege  of  killing. 

The  hauling  of  hogs  from  the  slaughter 
house  to  the  packers,  is  itself  a  large 
business,  employing  fully  fifty  of  the 
largest  class  of  wagons,  each  loading 
from  sixty  to  one  hundred  and  ten  hogs 
at  a  load. 

The  hogs  are  taken  into  the  pork 
houses  from  the  wagons,  and  piled  up  in 
rows  as  high  as  possible.  Another  set  of 
hands  carry  them  to  the  scales,  where 
they  are  usually  weighed  singly  for  the 
advantage  of  the  draft.  They  are  taken 
hence  to  the  blocks  where  the  head  and 
feet  are  first  struck  off,  each  blow  need- 
ing no  repetition.  The  hog  is  then  cloven 
into  three  parts,  separating  the  ham  and 
shoulder  ends  from  the  middle.  These 
are  again  divided  into  single  hams, 
shoulders,  and  sides.  The  leaf  is  then 
torn  out,  and  every  piece  is  distributed, 
with  the  exactness  and  regularity  of 
machinery,  to  its  appropriate  pile.  The 
tenderloins,  usually  two  pounds  to  the 
hog,  are  sold  to  the  manufacturers  of 
sausages. 

The  hog  thus  cut  up  into  shoulders, 
hams,  and  middlings,  undergoes  further 
trimming  to  get  the  first  two  articles  in 
proper  shape.  The  size  of  the  hams  and 
shoulders  varies  with  their  appropriate 
markets,  and  with  the  price  of  lard, 
which,  when  high,  tempts  the  putter  up 
of  pork  to  trim  very  close,  and  indeed  to 
render  the  entire  shoulder  into  lard.  If 
the  pork  is  intended  to  be  shipped  off  in 
bulk,  or  for  the  smoke  house,  it  is  piled 
up  in  vast  masses,  covered  with  fine  salt 
in  the  proportion  of  fifty  pounds  salt  to 
two  hundred  pounds  weight  of  meat.  If 
otherwise,  the  meat  is  packed  away  in 
barrels  with  coarse  and  fine  salt  in  due 
proportions — no  more  of  the  latter  being 
employed  than  the  meat  will  require  for 
immediate  absorption,  and  the  coarse 
salt  remaining  in  the  barrel  to  renew  the 
pickle  whose  strength  is  withdrawn  by 
the  meat  in  process  of  time. 

The  different  classes  of  cured  pork, 
packed  in  barrels,  are  made  up  of  the 
different  sizes  and  conditions  of  hogs— 
the  finest  and  fattest  making  clear  and 
mess  pork,  while  the  residue  is  put  up 
into  prime  pork  or  bacon.  The  inspec- 
tion laws  require  that  clear  pork  shall  be 
put  up  of  the  sides  with  the  ribs  out. 
It  takes  the  largest  class  of  hogs  to  re- 
ceive this  brand.  Mess  pork — all  sides, 
with  two  rumps  to  the  barrel.  Prime— 
for  this  pork  of  lighter  weight  will  suffice. 
Two    shoulders,    two   jowls,   and  sides 


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CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


461 


enough  to  fill  the  barrel,  make  the  con- 
tents. Two  hundred  pounds  of  meat  is 
required  by  the  inspector,  but  one  hun- 
dred and  ninety-six  pounds,  packed 
here,  it  is  ascertained,  will  weigh  out 
more  than  the  former  quantity  in  the 
eastern  or  southern  markets. 

The  mess  pork  is  used  for  the  com- 
mercial marine  and  the  United  States 
navy.  This  last  class,  again,  is  put  up 
somewhat  differently,  by  specifications 
made  out  for  the  purpose.  The  prime  is 
packed  for  ship  use  and  the  southern 
markets.  The  clear  pork  goes  out  to  the 
cod  and  mackerel  fisheries.  The  New 
Englanders,  in  the  line  of  pickled  pork, 
buy  nothing  short  of  the  best. 

Bulk  pork  is  that  which  is  intended  for 
immediate  use  or  for  smoking.  The  for- 
mer class  is  sent  off  in  flat  boats  for  the 
lower  Mississippi.  It  forms  no  important 
element  of  the  whole,  the  great  mass  be- 
ing sent  into  the  smoke  houses,  each  of 
which  will  cure  a  hundred  and  seventy- 
five  thousand  to  five  hundred  thousand 
pounds  at  a  time.  Here  the  bacon,  as 
tar  as  possible,  is  kept  until  it  is  actually 
wanted  for  shipment,  when  it  is  packed 
in\  hogsheads  containing  from  eight  to 
nine  hundred  pounds,  the  hams,  sides, 
and  shoulders,  put  up  each  by  them- 
selves. The  bacon  is  sold  to  the  iron 
manufacturing  regions  of  Pennsylvania, 
Kentucky,  and  Ohio — to  the  fisheries  of 
Pennsylvania,  Maryland,  and  Virginia, 
and  to  the  coast  or  Mississippi  region 
above  New  Orleans.  Large  quantities 
are  disposed  of  also  for  the  consumption 
of  the  Atlantic  cities.  Flat  boats  leave 
here  about  the  first  of  July,  and  they  all 
take  down  more  or  less  bacon  for  the 
coast  trade. 

If  there  be  four  hundred  and  twenty 
thousand  hogs  cut  up  here  during  the 
present  season,  1847,  the  product  in  the 
manufactured  article  will  be  : — 
150.000  bbls.  Pork. 
21,000,000  lbs.   Bacon. 
13,800,000     "     Lard. 

These  are  the  products  thus  far  of  the 
pork  houses'  operations  alone.  That  is 
to  say,  the  articles  thus  referred  to  are 
put  up  in  these  establishments,  from  the 
hams,  shoulders,  sides,  leaf  lard,  and  a 
small  portion  of  the  jowls — the  residue  of 
the  carcases,  which  are  taken  to  the  pork 
houses,  leaving  them  to  enter  elsewhere 
into  other  departments  of  manufacture. 
The  relative  proportions  in  weight  of 
bacon  and  lard  rest  upon  probabilities. 
An  unexpected  demand  and  advance  in 
price  of  lard  would  greatly  reduce  the 


disparity  if  not  invert  the  proportion  of 
these  two  articles.  A  change  in  the 
prospects  of  the  value  of  pickled  pork, 
during  the  progress  of  packing,  would 
also  reduce  or  increase  the  proportion  of 
barelled  pork  to  the  bacon  and  lard. 

The  lard  made  here  is  exported  in 
packages  for  the  Havana  market,  where, 
besides  being  extensively  used,  as  in  the 
United  States,  for  cooking,  it  answers 
the  purpose  to  which  butter  is  applied  in 
this  country.  It  is  shipped  to  the  Atlan- 
tic markets  also,  for  local  use  as  well  as 
for  export  to  England  and  France,  either 
in  the  shape  it  leaves  this  market,  or  in 
lard  oil,  large  quantities  of  which  are 
manufactured  at  the  east. 

There  is  one  establishment  there,  which, 
besides  putting  up  hams,  &c,  extensive- 
ly, is  engaged  in  extracting  the  grease 
from  the  rest  of  the  hog.  This  will  pro- 
bably the  present  year,  1847,  operate  upon 
thirty  thousand  hogs.  It  has  seven  large 
circular  tanks — six  of  capacity  to  hold 
each  fifteen  thousand  pounds,  and  one  to 
hold  six  thousand  pounds — all  gross. 
These  receive  the  entire  carcase  with  the 
exception  of  the  hams,  and  the  mass  is 
subjected  to  steam  process  under  a  pres- 
sure of  seventy  pounds  to  the  square 
inch,  the  effect  of  which  operation  is  to 
reduce  the  whole  to  one  consistence,  and 
every  bone  to  powder.  The  fat  is  drawn 
off  by  cocks,  and  the  residuum,  a  mere 
earthy  substance,  as  far  as  made  use  of, 
is  taken  away  for  manure.  Besides  the 
hogs  which  reach  this  factory  in  entire 
carcases,  the  great  mass  of  heads,  ribs, 
back  bones,  tail  pieces,  feet,  and  other 
trimmings  of  the  hogs,  cut  up  at  different 
pork  houses,  are  sxibjected  to  the  same 
process,  in  order  to  extract  every  particle 
of  grease.  This  concern  alone  will  turn 
out  this  season  three  million  six  hundred 
thousand  pounds  lard,  five-sixths  of 
which  is  No.  1.  Nothing  can  surpass 
the  purity  and  beauty  of  this  lard,  which 
is  refined  as  well  as  made  under  steam 
processes.  Six  hundred  hogs  per  day 
pass  through  these  tanks  one  day  with 
auother. 

The  manufacture  of  lard  oil  is  accom- 
plished by  divesting  the  lard  of  one  of 
its  constituent  parts — stearine.  There 
are  probably  thirty  lard  oil  factories  here 
on  a  scale  of  more  or  less  importance. 
The  largest  of  these,  whose  operations 
are  probably  more  extensive  than  any 
other  in  the  United  States,  has  manufac- 
tured heretofore  into  lard  oil  and  stearine, 
one  hundred  and  forty  thousand  pounds 
monthly  all  the  year  round.    The  great 


462 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[pio 


increase  of  hogs  for  the  present  season 
will  probably  enlarge  that  business  this 
year  fifty  per  cent. 

Eleven  million  pounds  of  lard  will  be 
run  into  lard  oil  this  year,  two-sevenths 
of  which  aggregate  will  make  stearine, 
the  residue  lard  oil,  or  in  other  words, 
twenty-four  thousand  barrels  of  lard  oil, 
of  forty  to  forty-two  gallons  each.  The 
oil  is  exported  to  the  Atlantic  cities  and 
foreign  countries.  Much  the  larger  share 
of  this  is  of  inferior  lard,  made  of  mast 
fed  and  still  fed  hogs,  and  the  material, 
to  a  great  extent,  comes  from  a  distance, 
making  no  part  of  these  tables.  Lard  oil, 
besides  being  sold  for  what  it  actually  is, 
enters  largely  in  the  eastern  cities  into 
the  adulteration  of  sperm  oil,  and  in 
France  serves  to  reduce  the  cost  of  olive 
oil.  The  skill  of  the  French  chemists 
enables  them  to  incorporate  from  sixty- 
five  to  seventy  per  cent,  of  lard  oil  with 
that  of  the  olive.  The  presence  of  lard 
oil  can  be  detected,  however,  by  a  de- 
posit of  stearine,  small  portions  of  which 
always  remain  with  that  article,  fcnd  will 
be  found  at  the  bottom  of  the  bottle. 

The  star  candles  are  made  of  the  stearine 
expressed  from  the  lard  in  the  n  anufac- 
ture  of  lard  oil.  The  stearine  is  si  bjected 
to  hydraulic  pressure,  by  whicfc  three- 
eighths  of  it  is  discharged  as  an  impure 
oleine.  This  last  is  employed  in  the 
manufacture  of  soap.  Three  million 
pounds  of  stearine,  at  least,  hri  re  been 
made,  in  one  year,  into  star  canoes  and 
soap  in  these  factories,  and  they  are  pre- 
pared to  manufacture  six  thousand 
pounds  candles  average  per  da;-,  through- 
out the  whole  year.    The  manr  fticture  of 


1 50,000  barrels  pork 

21,000,000  pounds  bacon 

13,800,000      '•        No.  1  lard  .. 
1,000,000  gallons  lard  oil 


420,000  hogs  average,  including  seven 
pounds  gut  fat  to  each,  eighty-four  mil- 
lion pounds  as  the  carcase  weight  when 
dressed.    This  is  distributed  as  follows  : 

150,000  barrels  pork- -196  pounds 

net 29.400,000  lbs. 

Bacon 21,000,000    " 

Number  on*  or  leaf  lard 13,800,000   " 

Lard  or  grertse  run  into  lard  oil, 

stearine,  and  soap  oleine 5,000,000   " 

nferior  grease  for  soap 1,000,000   " 

ivaporaiion,    shrinkage,    waste 

cracklings,  and  offal  for  ma- 

nure 13,800,000   " 


81,000,000  lbs. 

The  value  of  all  this  depends  of  course 

u  the  foriegn  demand.    Last  year  the 


|  candles  this  year  will  probably  approach 
that  amount,  as  the  present  supply  pro- 
mises the  raw  material  in  abundance. 

From  the  slaughterers  the  offal  capable 
of  producing  grease  goes  to  another  de- 
scription of  grease  extractors,  where  are 
also  taken  hogs  dying  of  disease  or  by 
accident,  and  meat  that  is  spoiling  through 
unfavorable  weather  or  want  of  care.  The 
grease  tried  out  here  goes  into  the  soap 
manufacture.  Lard  grease  is  computed 
to  form  eighty  per  cent,  of  all  the  fat  used 
in  the  making  of  soap.  Of  the  ordinary 
soap  one  hundred  thousand  pounds  are 
made  weekly,  equal  at  four  cents  per 
pound  to  two  hundred  thousand  dollars 
per  annum.  This  is  exclusive  of  the  finer 
soaps,  and  of  soft  soap,  which  are  pro- 
bably worth  twenty-five  per  cent.  more. 

Glue  to  an  inconsiderable  amount  is 
made  of  the  hoofs  of  the  hogs. 

At  the  rear  of  these  operations  comes 
bristle  dressing  for  the  Atlantic  markets. 
This  business  employs  one  hundred 
hands,  and  affords  a  product  of  fifty-five 
thousand  dollars. 

Last  of  all  is  the  disposition  of  what 
cannot  be  used  for  other  purposes,  the 
hair,  hoofs,  and  other  offal.  These  are 
employed  in  the  manufacture  of  prussiate 
of  potash,  to  the  product  of  which  also 
contributes  the  cracklings  or  residuum 
left  on  expressing  the  lard.  The  prussiate 
of  potash  is  used  extensively  in  the  print 
factories  of  New  England,  for  coloring 
purposes.  The  blood  of  the  hogs  is 
manufactured  into  prussian  blue. 

A  brief  recapitulation  of  the  various 
manufactures  out  of  the  hog  at  this  point 
present : 

1,875.000  pounds  star  candles. 
5.200,000      "        bar  soap. 
7,300,000      u        fancy  and  soft  soaps. 
'50,000      "        prussiate  of  potash. 

pork,  bacon,  lard,  lard  oil,  star  candles, 
soap,  bristles,  &c,  exceeded  six  millions 
of  dollars  in  value.  This  year  it  will  pro- 
bably reach  eight  millions.  But  for  the 
reduced  prices,  which  a  greatly  increased 
product  must  create,  it  would* far  exceed 
that  value. 

The  buildings  in  which  the  pork  is 
put  up,  are  of  great  extent  and  capacity, 
and  in  every  part  thoroughly  arranged 
for  the  business.  They  generally  extend 
from  street  to  street,  so  as  to  enable  one 
set  of  operations  to  be  carried  on  without 
interfering  with  another.  There  are 
thirty  of  these  establishments,  besides  a 
number  of  minor  importance. 

The  stranger  here  during  the  packing, 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


463 


and  especially  the  forwarding  season  of 
the  article,  becomes  bewildered  in  the 
attempt  to  keep  up  with  the  eye  and  the 
memory  the  various  and  successive  pro- 
cesses he  has  witnessed,  in  following  the 
several  stages  of  putting  the  hog  into  its 
final  marketable  shape,  and  in  surveying 
the  apparently  interminable  rows  of  drays 
which  at  that  period  occupy  the  main 
avenues  to  the  river  in  continuous  lines 
going  and  returning,  a  mile  or  more  in 
length,  excluding  every  other  use  of 
those  streets,  from  daylight  to  dark.  Nor 
is  his  wonder  lessened  when  he  surveys 
the  immense  quantity  of  hogsheads  of 
bacon,  barrels  of  pork,  and  kegs  of  lard, 
for  which  room  cannot  be  found  on  the 
pork  house  floors,  extensive  as  they  are, 
and  which  are  therefore  spread  over  the 
public  landing,  and  block  up  every  vacant 
space  on  the  side  walks,  the  public  streets, 
and  even  adjacent  lots,  otherwise  vacant. 

It  may  appear  remarkable,  in  consider- 
ing the  facilities  for  putting  up  pork, 
which  many  other  points  in  Illinois,  In- 
diana, Ohio,  and  Kentucky  possess,  in 
their  greater  contiguity  to  the  neighbor- 
hoods which  produce  the  hogs,  and 
other  advantages  which  are  palpable,  that 
so  large  an  amount  of  this  business  is 
engrossed  at  Cincinnati.  It  must  be  ob- 
served, however,  that  the  raw  material  in 
this  business  (the  boa:)  constitutes  sixty 
per  cent,  of  the  value  when  ready  for  sale, 
and  being  always  paid  for  in  cash,  such 
heavy  disbursements  are  required  in  large 
sums,  and  at  a  day's  notice,  that  the  ne- 
cessary capital  is  not  readily  obtainable 
elsewhere  in  the  west.  Nor  in  an  article, 
which  in  the  process  of  curing  runs  great 
risks  in  sudden  changes  of  weather,  can 
the  packer  protect  himself,  except  where 
there  are  ample  means  in  extensive  sup- 
plies of  salt,  and  any  necessary  force  of 
coopers  or  laborers,  "to  put  on  'in  case  of 
emergency  or  disappointment  in  previous 
arrangements.  More  than  all,  the  facili- 
ties of  turning  to  account  in  various 
manufactures,  or  as  articles  of  food  in  a 
populous  community,  what  cannot  bo 
disposed  of  to  profit  elsewhere,  renders 
hogs  to  the  Cincinnati  packer  worth  at 
east  five  per  cent,  more  than  they  will 
command  at  any  other  point  in  the  Mis- 
sissippi valley. 

As  a  specimen  of  the  amazing  activity 
which  characterizes  all  the  details  of 
packing,  cutting,  &c.,  here  it  may  be 
stated,  that  two  hands,  in  one  of  our 
pork  houses,  in  less  than  thirteen  hours, 
cut  up  eight  hundred  and  fifty  hogs, 
averaging    over    two    hundred    pounds 


each,  two  others  placing  them  on  the 
blocks  for  the  purpose.  All  these  hogs 
were  weighed  singly  on  the  scales,  in  the 
course  of  eleven  hours.  Another  hand 
trimmed  the  hams  (seventeen  hundred 
pieces),  in  Cincinnati  style,  as  fast  as  they 
were  separated  from  the  carcases.  The 
hogs  were  thus  cut  up  and  disposed  of 
at  the  rate  of  more  than  one  to  the 
minute. 

Those  who  are  cognizant  to  the  import- 
ance of  the  domestic  market  will  not  be 
surprised  to  learn  by  the  table  of  our  ex- 
ports of  pork  to  foreign  countries,  the 
small  proportion  it  forms  to  the  quantity 
packed.  The  following  is  the  export 
table  for  seven  years  : 


Year.             Barrels. 

Year. 

1844 
1845 
1846 

Barrels. 

1840  66,281 

1841  132,390 

1842  180,039 

1843  80,310 

162.689 
161,609 
190,422 

More  than  three-fourths  of  these  ex- 
ports is  to  British  Colonies  in  America, 
and  to  the  West  India  Islands. 

Few  persons  at  the  east  can  realize  the 
size,  and  especially  the  fatness,  to  which 
hogs  arrive  in  the  west,  under  the  pro- 
fuse feeding  they  receive. 

The  following  are  specimens  of  hogs 
and  lots  of  hogs  killed  in  Cincinnati  this 
season  and  the  last : 

Hops.  Average  weight — lbs. 

7 720 

5.... 640 

22 403 

52 377 

50 375 

Of  these  were  nine — one  litter — weighing 
respectively  316,  444,  454,  452,  456,  516, 
526,  532. 

Hogs.  Average  weight— lbs. 

320 325 

657 305 

Few  if  any  of  these  hogs  were  over 
nineteen  months  old.  The  last  lot  is  ex- 
traordinary —  combining  quantity  and 
weight,  even  for  the  west.  They  were 
all  raised  in  one  neighborhood  in  Madi- 
son county,  Kentucky,  by  Messrs.  Cald- 
well, Campbell,  Ross,  and  Gentry,  the 
oldest  being  nineteen  months  in  age. 

The  value  of  these  manufacturing  op- 
erations to  Cincinnati  consists  in  the  vast 
amount  of  labor  they  require  and  create, 
and  the  circumstance  that  the  great  mass 
of  that  labor  furnishes  employment  to 
thousands,  at  precisely  the  very  season 
when  their  regular  avocations  cannot  be 


464 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[pin 


pursued.  Thus  there  are  perhaps  fifteen 
hundred  coopers  engaged  in  and  outside 
of  the  city,  making  lard  kegs,  pork  bar- 
rels, and  bacon  hogsheads:  the  city 
coopers  at  a  period  when  they  are  not 
needed  on  stock  barrels  and  other  coop- 
erage, and  the  country  coopers,  whose 
main  occupation  is  farming,  during  a 
season  when  the  farms  require  no  labor 
at  their  hands.  Then  there  is  another 
large  body  of  hands,  also  agriculturists, 
at  the  proper  season,  engaged  getting  out 
staves  and  heading,  and  cutting  hoop 
poles  for  the  same  business.  Vast  quan- 
tities of  boxes  of  various  descriptions  are 
made  for  packing  bacon,  for  the  Havana 
and  European  markets.  Lard  is  also 
packed  to  a  great  extent  for  export  in  tin 
cases  or  boxes,  the  making  of  which  fur- 
nishes extensive  occupation  to  the  tin 
plate  workers. 

If  we  take  into  view  farther  that  the 
slaughtering,  the  wagoning,  the  pork 
house  labor,  the  rendering  grease  and 
lard  oil,  the  stearine  and  soap  factories, 
bristle  dressing,  and  other  kindred  em- 
ployments, supply  abundant  occupation 
to  men,  who  in  the  spring  are  engaged  in 
the  manufacture  and  hauling  of  bricks, 
quarrying  and  hauling  stone,  cellar  dig- 
ging and  walling,  brick -laying,  plaster- 
ing, and  street  paving,  with  other  em- 
ployments, which  in  their  very  nature 
cease  on  the  approach  of  winter,  we  can 
readily  appreciate  the  importance  of  a 
business  which  supplies  labor  to  the  in- 
dustry of  probably  six  thousand  indivi- 
duals, who  but  for  its  existence  would  be 
earning  little  or  nothing  one-third  of  the 
year. 

The  United  States  census  of  1840  gives 
26,301,293,  as  the  existing  number  of 
hogs  of  that  date.  The  principal  increase 
since  is  in  the  west  owing  to  the  abund- 
ance of  corn  there,  and  that  quantity  may 
be  now  safely  enlarged  to  forty-five  mil- 
lions. This  is  about  the  number  assigned 
to  entire  Europe  in  1839,  by  McGregor, 
in  his  Commercial  Dictionary,  and  there 
is  probably  no  material  increase  there 
since,  judging  by  the  slow  advance  in  that 
section  ot  the  world  in  productions  of 
any  kind. 

PIN  MANUFACTURE.  A  pin  is  a 
small  bit  of  wire,  commonly  brass,  with 
a  point  at  one  end,  and  a  spherical  head 
at  the  other.  In  making  this  little  arti- 
cle, there  are  no  less  than  fourteen  dis- 
tinct operations: — 1.  Straightening  the 
wire.  The  wire,  as  obtained  from  the 
drawing  frame,  is  wound  about  a  bobbin 
or  barrel,  which  gives  it  a  curvature  that 


must  be  removed.     The  straightening 
engine  is  formed  by  fixing  6  or  7  nails 
upright  in  a  waving' line  on  a  board,  so 
that  the  void  space  measured  in  a  straight 
line  between  the  first  three  nails  may 
have  exactly  the  thickness  of  the  wire  to 
be  trimmed;    and  that  the  other  nails 
may  make  the  wire  take  a  certain  curve 
line,  which  must  vary  with  its  thickness. 
The  workman  pulls  the  wire  with  pincers 
through  among  these  nails,  to  the  length 
of  about  30  feet,  at  a  running  draught ; 
and  after  he  cuts  them  off,  he  returns 
for  as  much  more;   he  can  thus  finish 
600  fathoms  in  the  hour.     He  next  cuts 
these  long  pieces  into  lengths  of  3  or  4 
pins.    A  day's  work  of  one  man  amounts 
to  18  or  20  thousand  dozen  of  pin-lengths. 
— 2.  Pointing  is  executed  on  two  iron  or 
steel  grindstones,  by  two  workmen,  one 
of  Avhom  roughens,  and  the  other  fin- 
ishes.   Thirty  or  forty  of  the  pin  wires 
are  applied  to  the  grindstone  at  once,  ar- 
ranged in  one  plane,   between  the  two 
forefingers  and  thumbs  of  both  hands, 
which  give  them  a  rotatory  movement. — 
3.    C-utting  these  wires  into  pin-lengths. 
This  is  done  by  an  adjusted  chisel. — i. 
Twisting  of  the  wire  for  the  pin-heads. 
These  are  made  of  a  much  finer  wire, 
coiled  into  a  compact  spiral,  round  a  wire 
of  the  size  of  the  pins,  by  means  of  a 
small  lathe  constructed  for  the  purpose. 
— 5.   Cutting  the  heads.     Two  turns  are 
dexterously  cut  off  for  each  head,  by  a 
regulated  chisel.      A  skilful   workman 
may  turn  off  12,000  in  the  hour. — 6.  An- 
nealing the  heads.     They  are  put  into  an 
iron  ladle,  made  red-hot   over  an  open 
fire,  and  then  thrown  into  cold  water. — 
7.  Stamping  or  shaping  the  heads.    This 
is  done  oy  the  blow  of  a  small  ram.    The 
pin-heads  are  also  fixed  on  by  the  same 
operative,  who  makes  about  1500  pins  in 
the  hour,   or  from  12,000  to  15,000  per 
diem;  exclusive  of  one-thirteenth,  which 
is  always  deducted  for  waste  in  this  de- 
partment, as  well  as  in  the  rest  of  the 
manufacture. — 8.    Yellowing  or  cleaning 
the  pins  is  effected  by  boiling  them  for 
half  an  hour  in  sour  beer,  wine  lees,  or 
solution  of  tartar ;    after  which  they  are 
washed. — 9.     Whitening  or  tinning.      A 
stratum  of  about  6  pounds  of  pins  is  laid 
in  a  copper  pan,  then  a  stratum  of  about 
7  or  8  pounds  of  grain  tin  ;  and  so  alter- 
nately till  the  vessel  be  filled ;  Na  pipe  be- 
ing left  inserted   at  one   side,   to  per- 
mit   the   introduction  of  water    slowly 
at  the   bottom,    without  deranging    the 
contents.      When    the    pipe    is    with- 
drawn, its  space  is  filled  up  with  grain 


pip] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


465 


tin.  The  vessel  being  now  set  on  the 
fire,  and  the  water  becoming  hot,  its  sur- 
face is  sprinkled  with  4  ounces  of  cream 
of  tartar ;  after  which  it  is  allowed  to  boil 
for  an  hour.  The  pins  and  tin  grains 
are,  lastly,  separated  by  a  kind  of  cullen- 
der.— 10.  Washing  the  pins  in  pure  water. 
— 11.  Drying  and  polishing  them,  in  a 
leather  sack,  filled  with  coarse  bran, 
which  is  agitated  to  and  fro  by  two  men. 
— 12.  Winnowing,  by  fanners. — 13.  Prick- 
ing the  papers  for  receiving  the  pins. — 14. 
Papering,  or  fixing  them  in  the  paper. 
This  is  done  by  children,  who  acquire 
the  habit  of  putting  up  36,000  per  day. 

The  pin  manufacture  is  one  of  the 
greatest  prodigies  of  the  division  of  la- 
bor; it  furnishes  12,000  articles  for  the 
sum  of  three  shillings,  which  have  requir- 
ed the  united  diligence  of  fourteen  skil- 
ful operatives. 

The  above  is  an  outline  of  the  mode  of 
manufacturing  pins  by  hand  labor,  but 
several  beautiful  inventions  have  been 
employed  to  make  them  entirely,  or  in  a 
great  measure,  by  machinery  ;  and  there 
are  extensive  manufactures  of  these  arti- 
cles in  the  Northern  States. 

PINCHBECK.  An  alloy  of  copper  of 
zinc ;  a  species  of  brass  much  resembling 
what  is  now  termed  Mosaic  gold.  It  was 
brought  into  notice  by  a  person  of  the 
above  name. 

PIPES,  Glass  Water  Pipes.  Glass 
tubes  are  now  coming  into  a  very  general 
use  for  conveying  water.  Mr.  Wm.  T. 
De  Golyer,  of  Schenectady,  N.  Y.,  has  a 
patent  for  making  tubes  of  such  a  form 
as  to  couple  different  lengths  together, 
and  form  glass  conductors  for  water,  of 
any  length.  About  1000  rods  of  glass 
pipes  of  different  diameters  have  already 
been  laid  down  ;  and  Mr.  John  Matthews, 
of  First  Avenue,  N.  Y.,  has  tested  the 
strength  of  a  pine  \\  inch  in  diameter, 
made  at  the  Albany  Glass  Works,  and 
found  it  capable  of  standing  a  pressure 
of  200  lbs.  to  the  square  inch,  or  a  column 
of  water  450  feet  high.  Mr.  Wilson,  of 
Hastings,  a  few  miles  out  of  New  York, 
has  connected  these  glass  tubes  with  a 
hydraulic  ram  to  stand  a  pressure  of  80 
feet  high.  After  the  joints  were  ce- 
mented only  four  days,  the  water  was  let 
on,  and  the  joints  were  found  perfectly 
tight.  It  is  well  known  that  glass  is  al- 
most anti-corrosive,  and  resists  all  action 
of  the  elements  of  air  and  every  kind  of 
water  for  a  long  time ;  it  is  therefore  in- 
destructible, and  when  kept  from  the  ac- 
tion of  frost,  it  may  be  considered  as  en- 
during as  the  everlasting  hills.  By  them 
20* 


water  is  conveyed  in  all  its  purity  from 
the  fountain,  as  the  interior  is  too  smooth 
to  allow  any  weeds  or  vegetable  forma- 
tions to  adhere  to  it. 

PIPES,  Sheet  Iron.  Sheet  iron  pipes 
of  a  new  manufacture  have  lately  been 
introduced  into  England,  from  France, 
where  they  have  been  in  use  for  several 
years.  They  are  made  of  sheet  iron, 
which  is  bent  to  the  required  form  and 
then  strongly  riveted  together;  after 
which  they  are  coated  with  an  alloy  of 
tin,  and  the  longitudinal  joints  are  sol- 
dered so  as  to  render  them  both  air-tight 
and  water-proof.  In  order  to  give  them 
more  stiffness,  they  are  next  coated  on 
the  outside  with  asphalt  cement,  and,  if 
they  are  intended  to  be  used  as  water- 
pipes,  the  inside  is  also  coaLed  with  bitu- 
men, which  resists,  like  glass,  the  action 
of  acids  and  alkalies.  They  are  so  elastic 
that  they  will  bear  a  considerable  deflec- 
tion without  injuring  the  pipes,  or  caus- 
ing any  leakage  at  the  joints.  The  verti- 
cal joints  screw  together  in  the  same 
manner  as  cast  iron  gas-pipes.  These 
pipes  have  been  used  for  water,  for  gas, 
and  for  draining,  and  are  found  to  be 
more  economical  than  cast  iron,  besides 
being  less  liable  to  leak,  and  for  water- 
pipes  they  are  more  healthy  than  the 
common  ones. 

Iron  pipe  coated  with  glass. — At  a  late 
Soiree  of  the  President  of  the  Society  of 
Civil  Engineers,  London,  some  speci- 
mens of  iron  manufacture  were  exhibit- 
ed, coated  with  glass,  from  the  Smeth- 
wick  Iron  Works  of  Messrs.  Selby  and 
Johns,  near  Birmingham,  and  which 
would  appear  to  be  the  very  desideratum 
so  long  sought  for.  In  the  process  of 
coating  plates,  corrugated  or  plain  roof- 
ing, tiles,  tubing  of  all  kinds  and  dimen- 
sions, frying-pans,  grid-irons,  sauce-pans, 
kettles,  caldrons,  or  boilers,  in  lieu  of 
coppers,  and  a  host  of  other  implements, 
domestic,  agricultural,  and  manufactur- 
ing ;  the  article  is  first  thoroughly 
cleansed  in  an  acid  solution,  to  free  it 
from  every  particle  of  grease,  similar  to 
the  preparation  for  tinning,  zincing,  &c. 
It  is  then  covered  with  a  glutinous  pre- 
paration, over  which  is  laid  a  coat  of 
glass,  ground  to  a  fine  powder. 

The  article  is  then  introduced  into  a 
furnace  of  peculiar  construction  and  suffi- 
cient temperature,  in  which  the  glass  is 
fused,  and  the  intermediate  glutinous 
matter  being  evaporated,  the  glass 
fills  the  external  pores  of  the  metal, 
and  becomes  firmly  united  to  it ;  as  the 
manipilation  becomes  facilitated  by  prac- 


466 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[pn 


tice,  it  is  probable  that  the  cost  of  a  glass-  | 
coated  iron  material,   of  these  common 
kinds,  will  be  but  a  mere  nominal  trifle 
more  than  the  plain  articles  themselves. 

The  dinner  plates  shown  were  four 
ounces  lighter  than  an  earthenware  plate 
of  the  best  construction,  size  for  size. 
The  foliage  and  designs  are  in  relief,  and 
are  executed  by  a  kind  of  stenciling  ;  one 
color  being  put  on,  it  is  transferred  to 
the  kiln  ana  fixed;  then,  when  cold, 
another  color  is  added,  again  fixed,  and 
so  on  until  the  whole  pattern  is  applied. 

PIT  COAL.  Under  the  article  Coal, 
some  remarks  connected  with  the  nature 
of  the  deposit,  and  the  extent  of  its  beds 
in  this  country  are  given.  Under  the 
present  will  be  considered  chiefly  its  con- 
nection with  the  basin  form,  and  the 
want  of  horizontality  of  the  beds,  which 


^c^      V 

XXX 

B       V 

s\      r 

I 

\ 

N 

l       r        o 

u 

View  of  a  Horizontal  Coal-Field. 

induces  the  necessity  of  sinking  shafts, 
and  mining,  to  bring  it  to  the  surface. 
The  majority  of  the  pit  coal  is  found  in 
the  carboniferous  limestone  formation, 
or  that  of  the  system  of  rocks  found  in 
Northern  Pensylvania,  and  which  lie  im- 
mediately above  the  old  red  sandstone, 
the  Potsdam  sandstone  of  the  New  York 
system  of  rocks.  It  is  rare  indeed  to 
find  coal  in  a  stratum  rock  higher  than 
the  mountain  limestone,  although  it  does 
occur  in  the  oolitic  or  upper  secondary 
rocks.  Such  is  the  position  of  the  bed  of 
coal  at  Eichmond,  Virginia. 

The  simplest  form  of  a  coal-field  is  the 
entirely  basin  shape,  in  which  the  beds 
crop  out  all  round,  and  dip  down  toward 
the  centre. 

These  basins  are  generally  elliptical, 
sometimes  nearly  circular,  but  are  often 
very  eccentric,  being  much  greater  in 
length  than  in  breadth ;  and  trequently 
one  side  of  the  basin  on  the  shorter  dia- 
meter has  a  much  greater  dip  than  the 
other,  which  circumstance  throws  the 
trough  or  lower  part  of  the  basin  conca- 
vity much  nearer  to  the  one  side  than  to 
the  other.  From  this  view  of  one  entire 
basin,  it  is  evident  that  the  dip  of  the 


coal  strata  belonging  to  it  runs  in  oppo- 
site directions,  on  the  opposite  sides,  and 
that  all  the  strata  regularly  crop  out, 
and  meet  the  alluvial  cover  in  every  point 
of  the  circumferential  space,  like  the 
edges  of  a  nest  of  common  basins. 

It  is  from  this  basin  shape  that  all  the 
other  coal-fields  are  formed,  which  are 
segments  of  a  basin  produced  by  slips, 
dikes,  or  dislocations  of  the  strata.  If 
the  coals  were  dislocated  by  two  slips — 
one  slip  throwing  the  strata  down  to  the 
east,  and  the  other  slip  throwing  them  as 
much  up  in  the  same  direction,  the  out- 
crops of  the  coals  would  be  found  at  some 
distance  around. 

The  chief  difficulty  in  exploring  a  coun- 
try in  search  of  coal,  or  one  where  coal- 
fields are  known  to  exist,  arises  from  the 
great  thickness  of  alluvial  and  other 
cover,  which  completely  hides  the  out- 
crop or  basset  edge  of  the  strata,  called  by 
miners  the  rock-nead  t  as  also  the  fissures, 
dikes,  and  dislocations  of  the  strata, 
which  so  entirely  change  the  structure 
and  bearings  of  coal-fields,  and  cause  often 
great  loss  to  the  mining  adventurer. 
The  alluvial  cover,  on  the  other  hand,  is 
beneficial,  by  protecting  the  seams  of  the 
strata  from  the  superficial  waters  and 
rains,  which  would  be  apt  to  drown 
them,  if  they  were  naked. 

The  accompanying  cut  is  a  good  illus- 
tration of  a  coal-field  which  has  under- 
gone alterations  since  its  deposition : — 


Here  we  see  it  broken  into  three  subor- 
dinate coal-flelds,  formed  by  two  great 
faults  or  dislocations  of  the  strata ;  but, 
independently  of  these  fractures  across 
the  whole  series,  the  strata  continue 
quite  regular  in  their  respective  alterna- 
tions, and  preserve  nearly  unchanged 
their  angle  of  inclination  to  the  horizon. 
The  section  shows  a  south  coal-field 
dipping  northerly,  till  it  is  cut  across 
by  an  extensive  slope,  which  dislocate? 
the  coal  and  the  parallel  strata  to  the 
enormous  extent  of  1230  feet,  by  which 
all  the  coals  have  been  thrown  up,  not 
simply  to  the  day,  but  are  not  fonud 
again  till  we  advance  nearly  a  mile  north- 
ward, on  the  line  of  the  dip,  where  the 
identical  seams  of  coal,  shale,  &c.  are 


pit] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


467 


observed  once  more  with  their  regular 
inclination.  These  coals  of  the  middle 
area,  dip  regularly  northward  till  inter- 
rupted by  a  slip  running  opposite,  which 
dislocates  the  strata,  and  throws  them 
up  700  feet ;  that  is  to  say,  a  line  pro- 
longed in  the  direction  of  any  one  well- 
known  seam,  will  run  700  feet  above  the 
line  of  the  same  seam  as  it  emerges  after 
the  middle  slip.  Immediately  adjoining 
the  last  slip,  the  coals  and  coal-field 
resume  their  course,  and  clip  regularly 
northward,  running  through  a  longer 
range  than  either  of  the  other  two  mem- 
bers of  the  basin. 

With  regard  to  slips  in  coal-fields, 
there  is  a  general  law  connected  with 
them  as  to  the  position  of  the  dislocated 
strata,  which  is  this  : — When  a  slip  is 
met  with  in  the  course  of  working  the 
mines — if  when  looking  to  it,  the  vertical 
line  of  the  slip  or  fissure,  it  forms  an 
acute  angle  with  the  line  of  the  pave- 
ment upon  which  the  observer  stands, 
we  are  certain  that  the  strata  are  dislo- 
cated downwards  upon  the  other  side  of 
the  fissure.  On  the  contrary,  if  the 
angle  formed  by  the  two  lines  above- 
mentioned  is  obtuse,  we  are  certain  that 
the  strata  are  dislocated  or  thrown  up- 
wards upon  the  other  side  of  the  fissure. 
When  the  angle  is  90°,  or  a  right  angle, 
it  is  altogether  uncertain  whether  the 
dislocation  throws  up  or  down  on  the 
opposite  side  of  the  slip.  When  dikes 
intercept  the  strata,  they  generally  only 
separate  the  strata  the  width  of  the  dike, 
without  any  dislocation,  either  up  or 
down ;  so  that  if  a  coal  is  intercepted  by 
a  dike,  it  is  found  again  by  running  a 
mine  directly  forward,  corresponding  to 
the  angle  or  inclination  of  the  coal  with 
the  horizon. 

The  following  is  the  description  of  the 
several  varieties  of  coal  as  given  by  Dr. 
lire:— 

1.  Cubical  coal. — It  is  black,  shining, 
compact,  moderately  hard,  but  easily 
frangible.  When  extracted  in  the  mine, 
it  comes  out  in  rectangular  masses,  of 
which  the  smaller  fragments  are  cubical. 
The  lamella?  {reed  of  the  coal)  are  always 
parallel  to  the  bed  or  plane  on  which  the 
coal  rests ;  a  fact  which  holds  generally 
with  this  substance.  There  are"  two  va- 
rieties of  cubical  coal :  the  open-bun  in g 
and  tiie  caking.  The  latter,  however 
small  its  fras-ments  may  be,  is  quite 
available  for  fuel,  in  consequence  of  its 
agglutinating  into  a  mass  at  a  moderate 
heat,  by  the  abundance  of  its  bitumen. 
This  kind  is  the  true  smithy  or  forge- 


coal,  because  it  readily  forms  itself  into  a 
vault  round  the  blast  of  the  bellows, 
which  serves  for  a  cupola  in  concentrat- 
ing the  heat  on  objects  thrust  into  the 
cavity. 

The  open-burning  cubical  coals  are 
known  by  several  local  names  ;  the  rough 
coal  or  clod  coal,  from  the  large  masses 
in  which  they  may  be  had,  and  the  cherry 
coal,  from  the  cheerful  blaze  with  which 
they  spontaneously  burn ;  whereas  the 
caking  coals,  such  as  most  of  the  New- 
castle qualities,  require  to  be  frequently 
poked  iu  the  grate.  Its  specific  gravity 
varies  from  1-25  to  1-4. 

2.  Slate  or  splint  coal. — This  is  dull- 
black,  very  compact,  much  harder,  and 
more  difficultly  frangible  than  the  pre- 
ceding. It  is  readily  fissile,  like  sfate, 
but  powerfully  resists  the  cross  fracture, 
which  is  conchoidal.  Specific  gravity 
from  1-26  to  1*40.  In  working,  it  sepa- 
rates in  large  quadrangular  sharp-edged 
masses.  It  burns  without  caking,  pro- 
duces much  flame  and  smoke,  unless  ju- 
diciously supplied  with  air,  and  leaves 
frequently  a  considerable  bulk  of  white 
ashes.  It  is  the  best  fuel  for  distilleries 
and  all  large  grates,  as  it  makes  an  open 
fire,  and  does  not  clog  up  the  bars  with 
glassy  scoriae.  I  found  good  spliut  coal 
of  the  Glasgow  field  to  have  a  specific 
gravity  of  1-266,  and  to  consist  of— car- 
bon, 70  9 ;  hydrogen,  4-3;  oxygen,  24-8. 

3.  Gannelcoal. — Color  between  velvet  and 
grayish  black ;  lustre  resinous  ;  fracture 
even ;  fragments  trapezoidal ;  hard  as 
splint  coal;  specific  gravity  1*23  to  1-23. 
In  working,  it  is  detached  in  four-sided 
columnar  'masses,  often  breaks  con- 
choidal, like  pitch,  kindles  very  readily, 
and  burns  with  a  bright  white  pro- 
jective flame,  like  the  wick  of  a  can- 
dle, whence  its  name.  It  occurs  most 
abundantly  in  the  coal-field  of  Wigan,  in 
Lancashire,  in  a  bed  4  feet  thick ;  and 
there  is  a  good  deal  of  it  in  the  Clydes- 
dale coal-field,  of  which  it  forms  the  low- 
est seam  that  is  worked.  It  produces 
very  little  dust  in  the  mine,  and  hardly 
soils  the  fingers  with  carbonaceous  mat- 
ter. Cannel  coal  from  Woodhall,  near 
Glasgow,  specific  gravity  1-228,  consists 
by  my  analysis  of— carbon,  72*22 ;  hydro- 
gepi  3*93;  oxygen,  21-05;  with  a  little 
azote  (about  2-8 "in  100  parts).  This  coal 
has  been  found  to  afford,  in  the  Scotch 
gas-works,  a  very  rich-burning  gas.  The 
azote  is  there  converted  into  ammonia,  of 
which  a  considerable  quantity  is  distilled 
over  into  the  tar-pit. 

4.  Glance  coal. — This  species  has  an 


468 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PIT 


iron-black  color,  with  an  occasional  iridis- 
cence,  like  that  of  tempered  steel ;  lustre 
in  general  splendent,  shining,  and  im- 
perfect metallic ;  does  not  soil ;  easily 
Frangible ;  fracture  flat  conchoidal ;  frag- 
ments sharp-edged.  It  burns  without 
flame  or  smell,  except  when  it  is  sul- 
phureous ;  and  it  leaves  a  white- colored 
ash.  It  produces  no  soot,  and  seems, 
indeed,  to  be  merely  carbon,  or  coal  de- 
prived of  its  volatile  matter  or  bitumen, 
and  converted  into  coke  by  subterranean 
calcination,  frequently  from  contact  with 
whin-dikes.  Glance  coal  abounds  in  Ire- 
land, under  the  name  of  Kilkenny  coal; 
in  Scotland  it  is  called  blind  coal,  from 
its  burning  without  flame  or  smoke ;  and 
in  Wales,  it  is  the  malting  or  stone  coal. 
It  contains  from  90  to  97  per  cent,  of  car- 
bon. Specific  gravity  from  1'3  to  1-5; 
increasing  with  the  proportion  of  earthy 
impurities. — ( Ure.) 

JJikes  and  faults  are  denominated  up- 
throw or  downthrow,  according  to  the 
position  they  are  met  with  in  working  the 
mine.  Thus,  in  figure  (p.  466),  if  the  niiner 
in  advancing  to  the  rise,  the  dike  a  b 
obviously  does  not  change  the  direction  ; 
but  c  n  is  a  downthrow  dike  of  a  certain 
number  of  fathoms  towards  the  rise  of 
the  basin,  and  k  f  is  an  upthrow  dike 
likewise  towards  the  rise.  On  the  other 
hand,  when  the  dikes  are  met  with  by 
the  miner  in  working  from  the  rise  to 
the  dip,  the  names  of  the  above  dikes 
would  be  reversed;  for  what  is  an  up- 
throw in  the  first  case,  becomes  a  down- 
throw in  the  second,  relative  to  the  min- 
ing operations. 

We  have  seen  that  hitches  are  small 
and  partial  slips  where  the  dislocation 
does  not  exceed  the  thickness  of  the  coal- 
seam  ;  and  they  are  correctly  enough 
called  steps  by  the  miner.  This  figure 
represents  the  operation  of  the  hitches  a, 
b,  c,  d,  e,  f,  o,  h,  on  the  coal  measures, 
though  observed  in  one  or  two  seams  of 
a  field,  they  may  not  appear  in  the  rest, 
as  is  the  case  with  dikes  and  faults. 


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T 


1.  The  brace-head. 

2.  The  common  rod. 

3.  The  double-box  rod ;  intermediate  piece. 

4.  The  common  chisel. 

5.  The  indented  chisel. 

6.  Another  of  the  same. 

7.  The  cross-mouthed  chisel. 

8.  The  wimble. 

9.  The  sludger,  for  bringing  up  the  mud. 

10.  The  rounder. 

11.  The  key  for  supporting  the  train  of  rods  at 
the  bore-mouth. 

12.  The  key  for  screwing  together  and  asunder 
the  rods. 

13.  The  topit,  or  top-piece. 

14.  The  beche,  for  catching  the  rod  when  it 
breaks  in  the  bore. 

15.  The  runner,  for  taking  hold  of  the  topit 

16.  The  tongucd  chisel. 

17.  The  right-handed  worm-screw. 
18    The  left-handed        do. 
J  9.  The  finger  grip  or  catch. 

The  boring  tools  used  for  mining  for         Of  fitting  or  winning  a  coal-field. — In 
coal  are  given  below : —  sinking  a  shaft  for  working  coal,  the 


pit] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


great  obstacle  to  be  encountered  is  water, 
particularly  in  the  first  opening  of  a  field, 
which  proceeds  from  the  surface  of  the 
adjacent  country;  for  every  coal  stratum, 
however  deep  it  may  lie  in  one  part  of 
the  basin,  always  rises  till  it  meets  the 
alluvial  cover,  or  crops  out,  unless  it  be 
met  by  a  slip  or  dike.  When  the  basset- 
edge  of  the  strata  is  covered  with  gravel 
or  "sand,  any  body  or  stream  of  water 
will  readily  percolate  downwards  through 
it,  and  fill  up  the  porous  interstices  be- 
tween the  coal-measures,  till  arrested 
by  the  face  of  a  slip,  which  acts  as  a 
valve  or  flood-gate,  and  confines  the  wa- 
ter to  one  compartment  of  the  basin, 
which  may,  however,  be  of  considerable 
area,  and  require  a  great  power  of  drain- 
age. 

In  reference  to  water,  coal-fields  are 
divided  into  two  kinds: — 1,  level  free 
coai ;  2,  coal  not  level  free.  In  the  prac- 
tice of  mining,  if  a  coal-field,  or  portion 
of  it,  is  so  situated  above  the  surface  of 
the  ocean,  that  a  level  can  be  carried 
from  that  plane  till  it  intersects  the  coal, 
all  the  coal  above  the  plane  of  intersec- 
tion is  said  to  be  level  free ;  but  if  a  coal- 
field, though  placed  above  the  surface  of 
the  ocean,  cannot,  on  account  of  the  ex- 
pense, be  drained  by  a  level  or  gallery, 
but  by  mechanical  power,  such  a  coal- 
field is  said  to  be  not  level  free. 

Besides  these  general  levels  of  drain- 
age, there  are  subsidiary  levels,  called 
off-takes  or  drifts,  which  discharge  the 
water  of  a  mine,  not  at  the  mouth  of  the 
pit,  but  at  some  depth  beneath  the  sur- 
face, where,  from  the  form  of  the  coun- 
try, it  may  be  run  off  level  free.  From 
20  to  30  fathoms  off-take  is  an  object  of 
considerable  economy  in  pumping ;  but 
even  less  is  often  had  recourse  to ;  and 
when  judiciously  contrived,  may  serve 
to  intercept  much  of  the  crop  water,  and 
prevent  it  from  getting  down  to  the  dip 
part  of  the  coal,  where  it  would  become 
a  heavy  load  on  a  hydraulic  engine. 

Day  levels  were  an  object  of  primary 
importance  with  the  early  miners,  who 
had  not  the  gigantic  pumping  power  of 
the  steam-engine  at  their  command. 
Levels  ought  to  be  no  less  than  4  feet 
wide,  and  from  5  feet  and  a  half  to  6  feet 
high ;  which  is  large  enough  for  carry- 
ing off  water,  and  admitting  workmen  to 
make  repairs  and  clear  out  depositions. 
When  a  day-level,  however,  is  to  serve 
the  double  purpose  of  drainage  and  an 
outlet  for  coals,  it  should  be  nearly  5  feet 
wide,  and  have  its  bottom  gutter  covered 
over.    In  other  instances  a  level  not  only 


carries  off  the  water  from  the  colliery; 
but  is  converted  into  a  canal  for  bearing 
boats  loaded  with  coals  for  the  market. 
Some  subterranean  canals  are  nine  feet 
wide,  and  twelve  feet  high,  with  five  feet 
depth  of  water. 

If  in  the  progress  of  driving  a  level, 
workable  coals  are  intersected  before 
reaching  the  seam  which  is  the  main  ob- 
ject of  the  mining  adventure,  an  air-pit 
may  be  sunk,  of  such  dimensions  as  to 
serve  for  raising  the  coals.  These  air- 
pits  do  not  in  general  exceed  7  feet  in 
diameter;  and  they  ought  to  be  always 
cylindrical. 

*  When  a  coal-basin  is  so  situated  that  it 
cannot  be  rendered  level  free,  the  winning 
must  be  made  by  the  aid  of  machinery. 
The  engines  at  present  employed  in  the 
drainage  of  coal-mines  are  : — 

1.  The  water  wheel,  and  water-pressure 
engine. 

2.  The  atmospheric  steam-engine  of 
Newcomen. 

3.  The  steam-engine,  both  atmospheric 
and  double-stroke,  of  Watt. 

4.  The  expansion  steam-engine  of 
Woolf. 

5.  The  high-pressure  steam-engine 
without  a  condenser. 

The  depth  at  which  the  coal  is  to  be 
won,  or  to  be  drained  of  moisture,  regu- 
lates the  power  of  the  engine  to  be  ap- 
plied, taking  into  account  the  probable 
quantity  of  water  which  may  be  found,  a 
circumstance  which  governs  the  diameter 
of  the  working  barrels  of  the  pumps. 
Experience  has  proved,  that  in  opening 
collieries,  even  in  new  fields,  the  water 
may  generally  be  drawn  off  by  pumps  of 
from  10  to  15  inches  diameter ;  excepting 
where  the  strata  are  connected  with 
rivers,  sand-beds  filled  with  water,  or 
marsh-lands.  As  feeders  of  water  from 
rivers  or  sand-beds  may  be  hindered 
from  descending  coal-pits,  the  growth 
proceeding  from  these  sources  need  not 
be  taken  into  account;  and  it  is  ob- 
served, in  sinking  shafts,  that  though 
the  influx  which  cannot  be  cut  off  from 
the  mine,  may  be  at  first  very  great,  even 
beyond  the  power  of  the  engine  for  a 
little  while,  yet  as  this  excessive  flow  of 
water  is  frequently  derived  from  the 
drainage  of  fissures,  it  eventually  be- 
comes manageable.  An  engine  working 
the  pumps  for  8  or  10  hours  out  of  the 
24,  is  reckoned  adequate  to  the  winning 
of  a  new  colliery,  which  reaps  no 
advantage  from  neighboring  hydraulic 
powers. 

When  the  engine-pit  is  sunk,  and  the 


470 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PIT 


/odgment  formed,  a  mine  is  then  run  in 
the  coal  to  the  rise  of  the  field,  or  a  crop- 
ping from  the  engine-pit  to  the  second 
pit.  This  mine  may  be  6  or  8  feet  wide, 
and  carried  either  in  a  line  directly  to 
the  pit  bottom,  or  at  right  angles  to  the 
backs  or  web  of  the  coal,  until  it  is  on  a 
line  with  the  pit,  where  a  mine  is  set  off, 
upon  one  side,  to  the  pit  bottom.  This 
mine  or  gallery  is  carried  as  nearly  par- 
allel to  the  backs  as  possible,  till  the  pit 
is  gained.  The  next  step  is  to  drive  the 
drip-head  or  main-levels  from  the  en- 
gine-pit bottom,  or  from  the  dip-hand  of 
the  backset  immediately  contiguous  to 
the  engine-pit  bottom.  In  this  business, 
the  best  colliers  are  always  employed,  as 
the  object  is  to  drive  the  gallery  in  a 
truly  level  direction,  independently  of  all 
sinkings  or  risings  of  the  pavement. 
For  coal  seams  of  ordinary  thickness, 
this  gallery  is  usually  not  more  than  6 
feet  wide ;  'observing  to  have  on  the  dip 
side  of  the  gallery  a  small  quantity  of 
water,  like  that  of  a  gutter,  so  that  it  will 
always  be  about  4  or  6  inches  deep  at  the 
forehead  upon  the  dip-wall.  When  the 
level  is  driven  correctly,  with  the  proper 
depth  of  water,  it  is  said  to  have  dead 
water  at  the  forehead.  In  this  operation, 
therefore,  the  miner  pays  no  regard  to 
the  backs  or  cutters  ot  the  coal ;  but  is 
guided  in  his  line  of  direction  entirely  by 
the  water  level,  which  he  must  attend  to 
solely,  without  regard  to  slips  or  disloca- 
tions of  the  strata  throwing  the  coal  up 
or  down. 

We  shall  now  describe  briefly  the  mo- 
dern modes  of  working  coals  a-dipping 
of,  and  deeper  than,  the  engine-pit  oot- 
tom.  One  of  these  consists  in  laying  a 
working  pump  barrel  with  a  long  wind- 
bore  at  the  bottom  of  the  downset  mine, 
furnished  with  a  smooth  rod  working 
through  a  collar  at  the  top  of  the  working 
barrel.  Atone  side  of  this,  near  the  top,  a 
kneed  pipe  is  attached,  and  from  it  pipes 
are  carried  to  the  point  of  delivery, 
either  at  the  engine-pit  bottom  or  day- 
level.  The  spears  are  worked  sometimes 
by  rods  connected  with  the  machinery  at 
the  surface  ;  in  which  case  the  spears,  if 
very  long,  are  either  suspended  from 
swing  or  pendulum  rods,  or  move  on 
friction  rollers.  But  since  the  action  of 
the  spears,  running  with  great  velocity 
the  total  length  of  the  engine  stroke,  very 
soon  tears  every  thing  to  pieces,  the  mo- 
tion of  the  spears  under  ground  has  been 
reduced  from  6  or  8  feet,  the  length  of 
the  engine  stroke,  to  about  15  inches ; 
and  the  due  speed  in  the  pump  is  effect- 


ed by  the  centring  of  a  beam,  and  the  at- 
tachment of  the  spears  to  it.  The  spears 
are  fastened  by  a  strong  bolt,  which 
passes  through  the  beam  ;  and  there  are 
several  holes,  by  means  of  which  the 
stroke  in  the  pumps  can  be  lengthened 
or  shortened  at  convenience.  The  move- 
ment of  the  spears  is  regulated  by  a 
strong  iron  quadrant  or  wheel  at  the  bot- 
tom. 

In  level  free  coals,  these  pumps  may  be 
worked  by  a  water-wheel,  stationed  near 
the  bottom  of  the  pit,  impelled  by  water 
falling  down  the  shaft,  to  be  discharged 
by  the  level  to  the  day  (day-level). 

But  the  preferable  plan  of  working 
under-dip  coal,  is  that  recently  adopted 
by  the  Newcastle  engineers  (England); 
and  consists  in  running  a  mine  a-dipping 
of  the  engine-pit,  in  such  direction  of 
the  dip  as  is  most  convenient ;  and  both 
coals  and  water  are  brought  up  the  rise 
of  the  coal  by  means  of  high  pressure  en- 
gines, working  with  a  power  of  from  30 
to  50  pounds  on  the  square  inch.  These 
machines  are  quite  under  command,  and, 
producing  much  power  in  little  space, 
they  are  the  most  applicable  for  under- 
ground work.  An  excavation  is  made 
for  them  in  the  strata  above  the  coal, 
and  the  air  used  for  the  furnace  under 
the  boiler,  is  the  returned  air  of  the  mine 
ventilation.  In  the  dip-mine  a  double 
tram-road  is  laid  ;  so  that  while  a  num- 
ber of  loaded  corves  are  ascending,  an 
equal  number  of  empty  ones  are  going 
down.  Although  this  improved  method 
has  been  introduced  only  a  few  years 
back,  under-dip  workings  have  been  al- 
ready executed  more  than  an  English 
mile  under-dip  of  the  engine-pit  bottom, 
by  means  of  three  of  these  high-pressure 
engines,  placed  at  equal  distances  in  the 
under-dip  mine.  It  may  hence  be  in- 
ferred, that  this  mode  of  working  is  sus- 
ceptible of  most  extensive  application ; 
and  in  place  of  sinking  pits  of  excessive 
depth  upon  the  clip  of  the  coal,  at  an 
almost  ruinous  expense,  much  of  the 
under-dip  coal  will  in  future  be  worked 
by  means  of  the  actual  engine  pits.  In 
the  Newcastle  district,  coals  are  now 
working  in  an  engine-pit  115  fathoms 
deep  under-dip  of  the  engine-pit  bottom, 
above  1600  yards,  and  fully  80  fathoms 
of  perpendicular  depth  more  than  the 
bottom  of  the  pit. 

If  an  engine-pit  be  sunk  to  a  given 
coal  at  a  certain  depth,  all  the  other  coals 
of  the  coal-field,  both  above  and  below 
the  coal  sunk  to,  can  be  drained  and 
worked  to  the  same  depth,  by  driving  a 


pla] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


i7l 


level  cross-cut  mine,  both  to  the  dip  and 
rise,  till  all  the  coals  are  intersected. 

PLANK  ROADS.  The  manifest  ad- 
vantage of  these  roads  over  every  other, 
has  led  to  their  general  adoption  in  some 
of  the  Western  States,  and  their  general 
extension  through  the  western  part  of 
this  State  (N.  Y.).  Next  to  steam  railroads, 
they  are  the  most  useful  form  of  road  for 
conveyance. 

In  the  most  generally  approved  system 
of  construction,  two  parallel  rows  of  small 
sticks  of  timber  (called  indifferently  sleep- 
ers, stringers  or  sills)  are  imbedded  in 
the  road,  three  or  four  feet  apart.  Flank, 
eight  feet  long  and  three  inches  thick, 
are  laid  upon  those  sticks  across  them,  at 
right  angles  to  their  direction.  A  side 
track  of  earth,  to  turn  out  upon,  is  care- 
fully graded.  Deep  ditches  are  dug  on 
each  side,  to  insure  perfect  drainage ;  and 
thus  is  formed  a  plank  road. 

Laying  them  out. — In  laying  out  a  plank 
road,  it  is  indispensable,  in  order  to  se- 
cure all  the  benefits  which  can  be  derived 
from  it,  to  avoid  or  cut  down  all  steep 
ascents. 

A  very  short  rise  of  even  considerable 
steepness  may,  however,  bo  allowed  to 
remain,  to  save  expense  ;  since  a  horse 
can,  for  a  short  time,  put  forth  extra  ex- 
ertion to  overcome  such  an  increased  re- 
sistance ;  and  the  danger  of  slipping  is 
avoided  by  descending  upon  the  earthen 
track. 

A  double  plank  track  will  rarely  be  ne- 
cessary. 

No  one  without  experience  in  the  mat- 
ter can  credit  the  amount  of  travel  which 
one  such  track  can  accommodate.  Over 
a  single  track  near  Syracuse,  161,000 
teams  passed  in  two  years,  averaging  over 
220  teams  per  day,  and  during  three  days 
720  passed  daily.  The  earthen  turn-out 
track  must,  however,  be  kept  in  good  or- 
der ;  and  this  is  ftisy,  if  it  slope  off  prop- 
erly to  the  ditch,  for  it  is  not  cut  with 
any  continuous  lengthwise  ruts,  but  is 
only  passed  over  by  the  wheels  of  the 
wagons  which  turn  off  from  the  track  and 
return  to  it.  They  thus  move  in  curves, 
which  would  very  rarely  exactly  hit  each 
other,  and  this  travel,  being  over  the 
earth,  tends  to  keep  it  in  shape  rather 
than  to  disturb  it. 

Covering.-  -The  planks  having  been 
properly  laid,  as  has  been  directed,  should 
be  covered  over  an  inch  in  thickness  with 
very  fine  gravel  or  pebbles,  from  which 
all  the  stones  or  pebbles  are  to  be  raked, 
so  as  to  leave  nothing  upon  the  surface 


of  the  road  that  could  be  forced  into  and 
injure  the  fibres  of  the  planks.  Tho  grit 
of  the  sand  soon  penetrates  into  the  grain 
of  the  wood  and  combines  with  the  fibres 
and  the  dropping  upon  the  road  to  form 
a  hard  and  tough  covering  like  felt,  which 
greatly  protects  the  wood  from  the  wheels 
and  horses'  shoes.  Sawdust  and  tan- 
bark  have  also  been  used. 

The  road  is  now  ready  for  use. 

Laying. — The  planks  should  be  laid 
directly  across  the  road,  at  right  angles, 
or  "square,"  to  its  line.  The  ends  ol  the 
planks  are  not  laid  evenly  to  a  line,  but 
project  three  or  four  inches  on  each  side 
alternately,  so  as  to  prevent  a  rut  being 
formed  by  the  side  of  the  plank  track, 
and  make  it  easier  for  loaded  wagons  to 
get  upon  it,  as  the  wheels,  instead  of 
scraping  along  the  ends  of  the  planks 
when  coming  towards  the  track  obliquely 
after  turning  off,  will,  on  coming  square 
against  the  edge  of  one  of  those  project- 
ing planks,  rise  directly  upon  it.  On  the 
Canada  roads  every  three  planks  project 
three  inches  on  each  side  of  the  road  al- 
ternately. 

Durability. — A  plank  road  may  require 
a  renewal  either  because  it  has  worn  out  at 
top  by  the  travel  upon  it,  or  because  it  has 
been  destroyed  at  the  bottom  by  rot.  But, 
if  the  road  have  travel  enough  to  make  it 
profitable  to  its  builders,  it  will  wear  out 
first,  and  if  it  does,  it  will  have  earned 
abundantly  enough  to  replace  it  twice 
over,  as  we  shall  see  presently.  The  lia- 
bility to  decay  is  therefore  a  secondary 
consideration  on  roads  of  importance. 

Decay. — As  to  natural  decay,  no  hem- 
lock road  has  been  in  use  long  enough  to 
determine  how  long  the  plank  can  be  pre? 
served  from  rot.  Seven  years  is  perhaps 
a  fair  average.  Different  species  of  hem- 
lock vary  greatly  ;  and  upland  timber  is 
always  more  durable  than  from  low  and 
wet  localities.  The  pine  roads  in  Canada 
generally  last  about  eight  years,  varying 
from  seven  to  twelve.  The  original  To- 
ronto road  was  used  chiefly  by  teams 
hauling  steamboat  wood,  and  at  the  end 
of  not  six  years  began  to  break  through 
in  places,  and  not  being  repaired,  was 
principally  gone  at  the  end  often  years. 
Having  been  poorly  built,  badly  drained, 
not  sanded,  and  no  care  bestowed  upon 
it,  it  indicates  the  minimum  of  durability. 
Oak  plank  cross-walks  are  in  Detroit,  the 

f»lank  being  laid  flat  as  on  those  of  pine, 
t  is  believed  that  oak  plank,  well  laid, 
would  last  at  least  twelve  or  fifteen  years. 
One  set  of  sleepers  will  outlast  two  plank- 


472 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[PLA 


ings.  Several  Canada  roads  have  been 
relaid  upon  the  old  sleepers,  thus  much 
lessening  the  cost  of  renewal. 

The  following  table  shows  the  number 
of  Plank  Roads  in  the  State  of  New 
York: 


Name. 

Opened. 

Miles. 

Great  Western  Albany 

1849 

11     I 

18 

Fonda  and  Garoga 

1845 

Fultonville  and  Johnstown. 

1849 

5 

1848 
1849 

15 

Utica  and  Burlington 

H 

Rome  and  Oswego 

1847 

60 

Rome  and  Western 

1849 

11 

1849 

9 

Rome  and  Madison 

1849 

22 

Salina  and  Central 

1847 

16 

Svracuse  and  Manlius 

1844 

8 

Syracuse  and  Bridgeport.. 

1849 

12 

Syracuse  and  Oswego 

1840 

32 

Syracuse  and  Liverpool.... 

1849 

11 

Syracuse  andTulIy 

1848 

25 

Split  Rock  Head 

1848 

Hannibal  and  Oswego 

11 

Hannibal  and  Oswego 

1849 

5 

Total  276±  miles.  The  tolls  which  the 
farmers  pay  are  not  taxes,  in  one  sense 
of  the  term — they  are  saved  in  the  larger 
loads  they  are  enabled  to  draw,  the  greater 
speed  at  which  they  are  enabled  to  travel, 
the  wear  and  tear  of  harness,  gearing, 
and  animal  strength ;  and  the  pleasure  of 
riding  on  a  smooth  plank  road  in  com- 
parison with  an  old  corderoy  one  is  very 
great. 

PLASTER  OF  PARIS.    (See  Gypsdm.) 

PLATED  MANUFACTURE.  The  sil- 
ver in  this  case  if  not  applied  to  ingots 
of  pure  copper,  but  to  an  alloy  consisting 
of  copper  and  brass,  which  possesses  the 
requisite  stiffness  for  the  various  articles. 

The  furnace  used  for  melting  that  al- 
loy, in  black-led  crucibles,  is  a  common 
air-furnace,  like  that  for  making  brass. 

The  ingot-moulds  are  made  of  cast- 
iron,  in  two  pieces,  fastened  together ; 
the  cavity  being  of  a  rectangular  shape,  3 
inches  broad,  Ik  thick,  and  18  or  20  long. 
There  is  an  elevated  mouth-piece  or  gate, 
to  give  pressure  to  the  liquid  metal,  and 
secure  solidity  to  the  ingot.  The  mould 
is  heated,  till"  the  grease  with  which  its 
cavity  is  besmeared  merely  begins  to 
Bmoke,  but  does  not  burn.  The  proper 
heat  of  the  melted  metal  for  casting,  is 
when  it  assumes  a  bluish  color,  and  is 
quite  liquid.  "Whenever  the  metal  has 
solidified  in  the  mould,  the  wedges  that 
tighten  its  rings  are  driven  out,  lest  the 
shrinkage  of  the  ingot  should  cause  the 
mould  to  crack.     (See  Brass.) 


The  ingot  is  now  dressed  carefully  with 
the  file  on  one  or  two  faces,  according  as 
it  is  to  be  single  or  double  plated.  The 
thickness  of  the  silver  plate  is  such  as  to 
constitute  one-fortieth  of  the  thickness 
of  the  ingot ;  or  when  this  is  an  inch  and 
a  quarter  thick,  the  silver  plate  applied  is 
one  thirty-second  of  an  inch  ;  being  by 
weight  a  pound  troy  of  the  former,  to 
from  8  to  10  pennyweights  of  the  latter. 
The  silver,  which  is  slightly  less  in  size 
than  the  copper,  is  tied  to  it  truly  with 
iron  wire,  and  a  little  of  a  saturated  solu- 
tion of  borax  is  then  insinuated  at  the 
edges.  This  salt  melts  at  a  low  heat,  and 
excludes  the  atmosphere,  which  might 
oxydize  the  copper,  and  obstruct  the 
union  of  the  metals.  The  ingot  thus 
prepared  is  brought  to  the  plating  fur- 
nace. 

The  furnace  has  i.r»  iron  door  with  a 
small  hole  to  look  through ;  it  is  fed  with 
coke,  laid  upon  a  grate  at  a  level  with  the 
bottom  of  the  door.  The  ingot  is  placed 
immediately  upon  the  coke,  the  door  is 
shut,  and  the  plater  watches  at  the  peep- 
hole the  instant  when  the  proper  solder- 
ing temperature  is  attained.  During  the 
union  ot  the  silver  and  copper,  the  sur- 
face of  the  former  is  seen  to  be  drawn  in- 
to immediate  contact  with  the  latter,  and 
this  species  of  riveting  is  the  signal  for  re- 
moving the  compound  bar  instantly  from 
the  furnace.  Were  it  to  remain  a  very  lit- 
tle longer,  the  silver  would  become  alloy- 
ed with  the  copper,  and  the  plating  be 
thus  completely  spoiled.  The  adhesion 
is,  in  fact,  accomplished  here  by  the  for- 
mation of  a  film  of  true  silver-solder  at 
the  surfaces  of  contact. 

The  ingot  is  next  cleaned,  and  rolled  to 
the  proper  thinness  between  cylinders ; 
being  in  its  progress  of  lamination  fre- 
quently annealed  on  a  small  reverberatory 
hearth.  After  the  last  annealing,  the 
sheets  are  immersed  ia  hot  diluted  sul- 
phuric acid,  and  scoured  with  fine  Calais 
sand  ;  they  are  then  ready  to  be  fashioned 
into  various  articles. 

In  plating  copper  wire,  the  silver  is 
first  formed  into  a  tubular  shape,  with 
one  edge  projecting  slightly  over  the  oth- 
er ;  through  which  a  red-hot  copper  cyl- 
inder being  somewhat  loosely  run,  the 
silver  edges  are  closely  pressed  together 
with  a  steel  burnisher,  whereby  they  get 
firmly  united.  The  tube,  thus  completed, 
is  cleaned  inside,  and  put  on  the  proper 
copper  rod,  which  it  exactly  fits.  The 
copper  is  left  a  little  longer  than  its 
coating  tube,  and  is  grooved  at  the  ex- 
tremities of  the  latter,  so  that  the  silver 


PLAJ 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


473 


edges,  being  worked  into  the  copper 
groove,  may  exclude  the  air  from  the  sur- 
face of  the  rod.  The  compound  cylinder 
is  now  heated  red-hot,  and  rubbed  brisk- 
ly over  with  the  steel  burnisher  in  a 
longitudinal  direction,  whereby  the  two 
metals  get  firmly  united,  and  form  a  solid 
rod,  ready  to  be  drawn  into  wire  of  any 
requisite  fineness  and  form  ;  as  flat,  half- 
round,  fluted,  or  with  mouldings,  accord- 
ing to  the  figure  of  the  hole  in  the  draw- 
plate.  Such  wire  is  much  used  for  mak- 
ing bread-baskets,  toast-racks,  snuffers, 
and  articles  combining  elegance  with 
lightness  and  economy.  The  wire  must 
be  annealed  from  tame  to  time  during  the 
drawing,  and  finally  cleaned,  like  the 
plates,  with  diluted  acid. 

The  greatest  improvement  made  in  this 
branch  of  manufacture,  is  the  introduc- 
tion of  silver  edges,  beads,  and  mould- 
ings, instead  of  the  plated  ones,  which  from 
their  prominence  had  their  silver  surface 
speedily  worn  off,  and  thus  assumed  a 
brassy  look.  The  silver  destined  to  form 
the  ornamental  edgings  is  laminated  ex- 
ceedingly thin;  a  square  inch  sometimes 
weighing  no  more  than  10  or  12  grains. 
This  is  too  fragile  to  bear  the  action  of 
the  opposite  steel  dies  of  the  swage  above 
described.  It  is  necessary,  therefore, 
that  the  sunk  part  of  the  die  should  be 
steel,  and  the  opposite  side  lead,  as  was 
observed  in  the  stamping ;  and  this  is 
the  method  now  generally  employed  to 
form  these  silver  ornaments.  The'inside 
shell  of  this  silver  moulding  is  filled  with 
soft  solder,  and  then  bent  into  the  requi- 
site form. 

The  base  of  candlesticks  is  generally 
made  in  a  die  by  the  stamp,  as  well  as 
the  neck,  the  dish  part  of  the  nozzle  or 
socket,  and  the  tubular  stem  or  pillar. 
The  different  parts  are  united,  some  with 
soft  and  other?  with  hard  solder.  The 
branches  of  candlesticks  are  formed  in 
two  semi-cylindrical  halves,  like  the  feet 
of  tea-urns*  When  an  article  is  to  be  en- 
graved on,  an  extra  plate  of  silver  is  ap- 
plied at  the  proper  part,  while  the  plate 
is  still  flat,  and  fixed  by  burnishing  with 
great  pressure  over  a  hot  anvil.  This  is 
a  species  of  welding. 

The  last  finish  of  plated  goods  is  given 
by  bnrnishing-tools  of  bloodstone^fixed 
in  sheet-iron  cases,  or  hardened  Bt*el, 
finely  polished. 

The  ingots  for  lamination  might  proba- 
bly be  plated  with  advantage  by  the  deli- 
cate pressure  process  employed  for  silver- 
ing copper  wire. 

Much  of  the  silver  in  plated  ware  is  now 


laid  on  by  electric  deposition;  and  old 
articles  are  re-silvered  by  this  process 
which  can  not  occur  in  the  old  way.  For  a 
description  of  the  process,  see  the  article 
Electro-Metallurgy. 

PLATE  POWDER  is  made  by  mixing 
4  oz.  of  prepared  chalk  with  1  oz.  of 
quick-silver,  prepared  with  manna  and 
chalk.  Or,  8  oz.  of  polisher's  putty,  8  oz. 
of  hartshorn,  and  1  pound  of  whiting. 

PLATINA-MOHK.  Platinum-black. 
The  following  is  Doberiener's  method  of 
making  this  powder : — 

Melt  platina  ore  with  double  its  weight 
of  zinc,  reduce  the  alloy  to  powder,  and 
treat  it  first  with  dilute  sulphuric  acid, 
and  next  with  dilute  nitric  acid,  to  oxyd- 
ize  and  dissolve  out  all  the  zinc,  which, 
contrary  to  one's  expectations,  is  some- 
what difficult  to  do,  even  at  a  boiling 
heat.  The  insoluble  black-gray  powder 
contains  some  osmiuret  of  iridium,  united 
with  the  crude  platinum.  This  compound 
acts  like  simple  platina-black,  after  it  has 
been  purified  by  digestion  in  potash  lye, 
and  washing  with  water.  Its  oxydizing 
power  is  so  great,  as  to  transform  not 
only  the  formic  acid  into  the  carbonic, 
and  alcohol  into  vinegar,  but  even  some 
osmic  acid,  from  the  metallic  osmium. 
The  above  powder  explodes  by  heat  like 
gunpowder. 

When  the  ■pXaX.mo.-mohr  prepared  by 
means  of  zinc  is  moistened  with  alcohol, 
it  becomes  incandescent,  and  emits  osmic 
acid  ;  but  if  it  be  mixed  with  alcohol  into 
a  paste,  and  spread  upon  a  watch-glass, 
nothing  but  acetic  acid  will  be  disen- 
gaged ;  affording  an  elegant  means  of 
diffusing  the  odor  of  vinegar  in  an  apart- 
ment. 

It  is  extensively  used  in  this  country 
and  Britain,  in  the  manufacture  of  acetic 
acid. 

PLATINUM.  A  metal  of  a  white  col- 
or, exceedingly  ductile,  malleable,  and 
difficult  of  fusion.  It  is  the  heaviest  sub- 
stanoe  known,  its  specific  gravity  being 
21.5.  It  undergoes  no  change  from  air 
or  moisture,  and  is  not  attacked  by  any 
of  the  pure  acids  ;  it  is  dissolved  by  chlo- 
rine and  nitromuriatic  acid,  and  is'oxyd- 
ized  at  high  temperatures  by  pure  potas- 
sa  and  lithia.  It  is  found  to  a  small  ex- 
tent in  Georgia,  in  the  gold  regions  ;  it 
has  not  yet  been  met  with  in  California. 
It  exists  in  New  Grenada,  in  Brazil,  and 
in  the  Ural  mountains  of  Russia.  It  is 
usually  in  small  grains  of  a  metallic  lus- 
tre, associated  or  combined  with  palla- 
dium, rhodium,  iridium,  and  osmium ; 
and  with  copper,  iron,   lead,    titanium, 


474 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


[PLA 


chromium,  gold  and  silver;  it  is  also 
usually  mixed  with  alluvial  sand.  The 
particles  are  seldom  so  large  as  a  small 
pea,  but  sometimes  lumps  have  been 
Found  of  the  size  of  a  hazel-nut  to  that 
of  a  pigeon's  egg.  Iu  1826,  it  was  first 
discovered  in  a  vein,  associated  with 
gold,  by  Boussingault,  in  the  province  of 
Atioqu'ia,  in  South  America.  When  a 
perfectly  clean  surface  of  platinum  is  pre- 
sented to  a  mixture  of  hydrogen  and 
oxygen  gas,  it  has  the  extraordinary  pro- 
perty of  causing  them  to  combine  so  as 
to  form  water,  and  often  with  such  rapid- 
ity as  to  render  the  metal  red  hot :  spon- 
gy platinum,  as  it  is  usually  called,  ob- 
tained by  heating  the  ammonio-chloride 
of  platinum,  is  most  effective  in  produc- 
ing this  extraordinary  result ;  and  a  jet 
of  hydrogen  directed  upon  it  may  be 
inflamed  by  the  metal  thus  ignited,  a 
property  which  has  been  applied  to  the 
construction  of  convenient  instruments 
for  procuring  a  light.  The  equivalent 
of  platinum  is  about  9S.  It  is  precipi- 
tated from  its  nitro-muriatic  solution  by 
sal  ammoniac,  which  throws  it  down  in 
the  form  of  a  yellow  powder,  composed  of 
bichloride  of  platinum  and  sal  ammoniac. 

It  is  generally  found  associated  with 
iridium,  osmium,  rhodium,  palladium, 
iron  and  copper.  By  far  the  greater  part 
of  the  platinum  of  commerce  comes  from 
the  Ural  mountains.  Only  a  limited  por- 
tion of  the  whole  is  allowed  by  the  Rus- 
sian government  to  come  into  the  market. 
Platinum  is  used  as  a  coin  metal  in  Rus- 
sia, and  the  following  is  the  mode  by 
which  it  is  obtained  pure  from  the  ore  in 
St.  Petersburgh : — 

One  part  of  the  ore  is  put  in  open  pla- 
tina  vessels,  capable  of  containing  from 
6  to  8  lbs.,  along  with  3  parts  of  muriatic 
acid  at  25°  B.  and  1  part  of  nitric  acid  at 
40°.  Thirty  of  these  vessels  are  placed 
upon  a  sand-bath  covered  with  a  glazed 
dome  with  movable  panes,  which  is  sur- 
mounted by  a  ventilating  chimney  to  car- 
ry the  vapors  out  of  the  laboratory.  Heat 
is  applied  for  eight  or  ten  hours,  till  no 
more  red  vapors  appear ;  a  proof  that  the 
whole  nitric  acid  is  decomposed,  though 
some  of  the  muriatic  remains.  After  set- 
tling, the  supernatant  liquid  is  decanted 
olf  into  large  cylindrical  glass  vessels,  the 
residuum  is  washed,  and  the  washing  is 
also  decanted  off.  A  fresh  quantity  of 
nitro-muriatic  acid  is  now  poured  upon 
the  residuum.  This  treatment  is  repeat- 
ed till  the  whole  solid  matter  has  eventu- 
ally disappeared.  The  ore  requires  for 
solution  from  ten    to  fifteen  times   its 


weight  of  nitro-muriatic  acid,  according 
to  the  size  of  its  grains. 

The  solutions  thus  made  are  all  acid  ;  a 
circumstance  essential  to  prevent  the  iri- 
dium from  precipitating  with  the  plati- 
num, by  the  water  of  ammonia,  which  is 
next  added.  The  deposit  being  allowed 
to  form,  the  mother-waters  are  poured 
off,  the  precipitate  is  washed  with  cold 
water,  dried,  and  calcined  in  crucibles  of 
platinum. 

The  mother-waters  and  the  washings  are 
afterwards  treated  separately.  The  first 
being  concentrated  to  one-twelfth  of  their 
bulk  in  glass  retorts,  on  cooling  they  let 
fall  the  iridium  in  the  state  of  an  ammo- 
niacal  chloride,  constituting  a  dark-pur- 
ple powder,  occasionally  crystallized  in 
regular  octahedrons.  The  washings  are 
evaporated  to  dryness  in  porcelain  ves- 
sels ;  the  residuum  is  calcined  and  treated 
like  fresh  ore ;  but  the  platinum  it  affords 
needs  a  second  purification. 

For  agglomerating  the  platinum,  the 
spongy  mass  is  pounded  in  bronze  mor- 
tars ;  the  powder  is  passed  through  a  fine 
sieve,  and  put  into  a  cylinder  of  the  in- 
tended size  of  the  ingot.  The  cylinder  is 
fitted  with  a  rammer,  which  is  forced  in  by 
a  coining  press,  till  the  powder  be  much 
condensed.  It  is  then  turned  out  of  the 
mould,  and  baked  36  hours  in  a  porcelain 
kiln,  after  which  it  may  be  readily  forged, 
if  it  be  pure,  and  may  receive  any  desired 
form  from  the  hammer.  It  contracts  in 
volume  from  l-6th  to  l-5th  during  the 
calcination.  The  cost  of  the  manufacture 
of  platinum  is  fixed  by  the  administra- 
tion at  32  franks  the  Russian  pound  ;  but 
so  great  a  sum  is  never  expended  upon  it. 

The  salts  of  platinum  are  not  much  in 
use.  The  bichloride  is  the  most  com- 
mon, and  is  made  by  digesting  nitro-mu- 
riatic on  platinum  in  slips;  it  is  used  in 
solution  as  a  test  for  potash,  as  it  precip- 
itates the  salts  of  that  alkali  as  a  yellow 
double  chloride  of  platinum  of  potassium, 
which  is  insoluble  in  alcohol.  It  is  also 
used  in  the  coating  of  surfaces  with  met- 
allic platinum.  The  solution  of  bichlo- 
ride is  washed  over  the  surface,  which  is 
then  heated  until  the  acid  element  is 
driven  off;  the  surface  is  then  polished. 
Sometimes  a  solution  of  the  double  chlo- 
ride of  soda  and  platinum  is  used.  Three 
immersions  of  the  article  to  be  coated 
suffice  ;  after  each  immersion  the  surface 
is  dried  and  polished  with  chalk. 

Imitation  of  Platinum. — Melt  together 
one  pound  of  brass  with  ten  ounces  of 
zinc;  but  as  brass  is  composed  of  copper 
and  zinc,  in  the  proportion  of  about  three 


PLO] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


475 


pounds  of  the  former  to  one  pound  of 
the  latter,  equal  parts  of  the  copper  and 
zinc  will  produce  the  same  compound  in 
imitation  of  platina. 

PLOUGH.  An  implement  drawn  by 
horses  and  guided  by  a  driver,  by  which 
the  surface  of  the  soil  is  cut  into  longi- 
tudinal slices,  and  successively  raised  up 
and  turned  over.  The  object  of  the  ope- 
ration is  to  expose  a  new  surface  to  the 
action  of  the  air,  and  to  render  it  fit  for 
receiving  the  seed,  or  for  harrowing,  or  for 
other  operations  of  agriculture.  Ploughs 
are  of  two  kinds  ;  those  without  wheels, 
commonly  called  swing-ploughs,  and  those 
with  one  or  more  wheels,  called  wheel- 
ploughs.  The  essential  parts  which  com- 
pose both  kinds  of  plougns  arc,  the  beam 
by  which  it  is  drawn ;  the  stilts  or  han- 
dles by  which  the  ploughman  guides  it, 
being  two  levers  connected  with  the 
beam ;  the  coulter  fixed  into  the  beam, 
by  which  the  furrow-slice  is  cut;  the 
share,  also  attached  to  the  beam,  by  which 
the  slice  is  raised  up  ;  and,  finally,  the 
mould-board,  by  which  the  slice  is  turned 
over.  The  most  improved  wheel-plough  is 
the  same  implement,  with  awheel  attach- 
ed to  the  beam,  for  the  purpose  of  keep- 
ing the  share  at  a  uniform  distance  be- 
neath the  surface.  The  subsoil  plough, 
the  invention  of  Mr.  Smith,  of  Deanston,  in 
Stirling,  Scotland,  is  the  swing-plough  of  a 
somewhat  stronger  construction  than  that 
in  common  use,  but  without  the  coulter 
and  the  mould-board.  The  use  of  this 
implement  is  to  follow  the  common  plough, 
and  loosen  the  subsoil  at  the  bottom  of 
the  furrow  without  raising  it  to  the  sur- 
face. The  most  improved  form  of  this 
implement  contains  a  muzzle  (the  instru- 
ment by  which  it  is  drawn),  so  contrived 
as  that  the  horses  may  walk  on  the  firm 
soil.  The  use  of  the  subsoil-plough  is  one 
of  the  greatest  modern  improvements 
that  has  been  introduced  into  the  culture 
of  arable  land.  Draining- ploughs  are  of 
different  kinds.  The  mole-plough,  instead 
of  a  share  and  mould-board,  has  a  small 
iron  cylinder  attached  to  the  lower  ex- 
tremity of  the  coulter,  and  which,  being 
drawn  through  grass  land,  leaves  in  its 
track  a  small  opening,  which  has  been 
compared  to  the  underground  track  of  a 
mole,  and  into  which  the  water  percolates 
from  the  surface  through  the  narrow  slit 
formed  by  the  upper  part  of  the  coulter, 
and  is  thus  carried  off  to  an  open  drain. 
The  other  kinds  of  draining-ploughs  cut 
out  the  soil,  raise  it  to  the  surface,  and 
turn  it  over  in  the  manner  of  the  common 
plow,  thus  leaving  a  deep  furrow,  which 


is  commonly  farther  deepened  and  modi- 
fied by  the  spade,  and  afterwards  partial- 
ly filled  with  stones,  draining  tiles,  or 
other  materials,  through  which  water 
may  find  its  way,  and  finally,  covered 
with  the  surface  soil.  Draining-ploughs, 
though,  in  theory,  promising  a  saving  of 
manual  labor,  yet,  in  practice,  are  found 
inconvenient,  from  the  number  of  horses 
required  to  work  them.  Their  use  is, 
therefore,  generally  confined  to  free, 
deep,  loamy  soils,  with  an  even  surface. 

In  no  country  is  there  a  better  test  of 
the  advancement  of  agriculture  than  in 
the  condition  of  the  ploughs,  and  the  im- 
provement in  their  shape.  Within  the 
tropics,  but  little  attention  is  paid  to  the 
use  of  the  plough,  and  in  Cuba  the  plough 
used  is  of  the  rudest  form:  a  pointed  piece 
of  iron,  shaped  like  a  wedge,  attached  to 
a  wooden  tongue,  and  drawn  by  a  pair  of 
oxen,  without  yokes ;  the  beasts  there 
bear  the  weight  of  their  burden  upon 
their  heads  (not  necks),  and  pull  by  their 
foreheads,  the  rope  being  drawn  tightly 
around  the  horns.  Of  course,  the  plough 
just  described  turns  no  row,  but  merely 
roots  up  the  ground. 

There  are  ploughs  for  almost  every  situ- 
ation and  soil,  in  addition  to  several  varie- 
ties which  are  exclusively  used  for  the 
subsoil.  Some  are  for  heavy  lands,  and 
some  for  light ;  some  for  stony,  and  some 
for  land  full  of  roots  ;  while  several  are 
made  expressly  for  breaking  up  the  un- 
tilled  prairies  of  the  west.  Some  are 
fitted  for  deep,  and  some  for  shallow 
draining.  There  is  a  great  economy  in 
the  use  of  many  ploughs,  and  it  is  desira- 
ble that  every  good  farm  should  be  sup- 
plied with  varieties  of  this  useful  imple- 
ment. 

There  are  upwards  of  fifty  various  kinds 
of  ploughs,  such  as  cotton,  rice,  and  sugar 
ploughs,  two  and  four-horse  ploughs, 
some  of  which  have  clevies  attached  to 
them,  thus  enabling  the  off-horse  in 
ploughing  wet  meadow  to  walk  on  the 
solid  ground,  instead  of  a  miry  fresh- 
ploughed  furrow:  they  also  answer  for 
shallow  ditching.  There  are  double 
mould-board  ploughs  and  subsoil  ploughs, 
with  wheel  clevies  and  draft  rod.  One- 
horse  ploughs,  with  single  and  double 
mould-board  ;  the  latter  work  excellently 
between  the  rows  of  root  crops  and  corn, 
when  not  beyond  42  inches  apart,  as  they 
turn  the  furrow  both  ways,  thus  doing 
the  double  work  of  a  single  mould-board. 

The  plough,  which,  previous  to  1848, 
had  been  so  varied  in  its  construction  as 
to  form  the  basis  of  claims  for  between 


476 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PLO 


three  and  four  hundred  American  pa- 
tents, still  continues  to  present  slight 
modifications.  But  of  the  eleven  applica- 
tions patented  during  the  year  most  are 
for  minor  points  of  invention.  One  of 
the  most  interesting  of  this  class  of  im- 
plements is  the  combined  plough,  remark- 
able for  its  number  of  adjustments  for 
the  various  purposes  of  ploughing  and 
cultivating  the  soil.  The  instrument  is 
susceptible  of  change  from  a  combined 
plough  into  a  cultivator,  and  with  devices 
tor  several  changes  even  as  a  cultivator. 
As  a  combined  plough,  it  consists  of  a 
frame-work  of  wood  for  supporting  the 
standards  for  the  changeable  reversible 
shares  or  teeth,  the  outline  of  which  is 
of  a  rhomboidal  shape  ;  the  bottom  edges 
of  which  shares  are  horizontal,  and  the 
forward  points  of  which  are  turned  to 
the  right  or  left,  inward  or  outward,  ac- 
cording to  the  direction  in  which  the  soil 
is  to  be  thrown.  A  vertical  cross  section 
through  the  share  gives  the  form  of  the 
letter  S,  so  that,  when  running  in  one 
direction,  it  scrapes  the  soil  up,  and 
when  reversed  back  side  before,  its  oper- 
ation is  to  smooth  it  down,  answering 
the  purpose  of  a  roller,  such  as  used  for 
covering  planted  grain.  The  share  part 
nas  an  upside  down  adjustment  to  fasten 
it  to  the  standard,  so  that  when  the  bot- 
tom is  worn  out,  the  share  part  may  be 
inverted,  and  used  again  for  the  same 
length  of  time.  If  used  as  a  gang  plough, 
it  has  an  adiustable  landside  to  be  at- 
tached to  each  share,  so  as  to  guide  the 
plough  and  prevent  it  from  running  to 
the  right  or  left,  as  it  might  otherwise 
do.  "When  the  instrument  is  to  be  used 
as  a  cultivator  for  pulverizing  the  soil, 
the  landsides  being  removed,  the  teeth 
or  shares  may  be  set,  some  inclining  in- 
ward and  some  outward,  so  that  the  for- 
ward teeth  may  throw  the  dirt  inward, 
for  example,  arid  the  rear  teeth  throw  it 
outward.  When  the  teeth  have  been 
set  to  work  as  a  cultivator,  and  it  is  re- 
quired to  use  the  instrument  as  a  roller, 
or  as  a  substitute  for  the  harrow,  for 
covering  in  or  pressing  down  the  grain, 
the  tongue  is  reversed,  and  the  instru- 
ment becomes  a  substitute  for  the  roller. 
Although  this  instrument  possesses  a 
great  variety  of  changes  and  adjustments, 
only  a  limited  claim  couldbe  granted  for 
it. 

A  minor  improvement  has  been  added 
to  the  plough  for  ploughing  among  corn  ; 
which  consists  of  a  common  plough  hav- 
ing a  cross-beam  fastened  near  the  for- 
ward end  of  the  beam,  and  two  cultiva- 


tor teeth  projecting  downward  from  the 
ends  of  the  cross-beam,  for  the  purpose 
of  tearing  up  and  loosening  the  soil. 
Between  this  cross-beam  and  the  plough, 
and  partly  over  the  anterior  part  of  the 
mould-board,  and  in  a  direction  oblique 
to  the  line  of  the  furrow,  there  is  ar- 
ranged a  strip  of  wood  or  metal  called  a 
guard,  the  object  of  which  is  to  prevent 
the  large  masses  of  earth  thrown  up  by 
the  plough  from  falling  upon  the  young 
plants.  This  furrow  guard  is  so  elevated 
as  to  be  above  the  ordinary  level  of  a 
small  furrow,  and  its  chief  merit  seems 
to  consist  in  its  adaptation  to  ploughing 
among  corn  while  the  plants  are  so  small 
as  to  be  liable  to  be  covered  up  by  the 
ordinary  plough,  when  used  without  such 
protection. 

PLOUGHING.  The  act  of  turning 
over  the  soil  by  means  of  the  plough. 
Trench  ploughing  is  effected  by  the 
plough  passing  twice  along  the  same 
furrow ;  the  first  time  for  the  purpose  of 
throwing  the  surface  soil  into  the  bottom 
of  the  furrow ;  and  the  second  time  for 
raising  a  furrow-slice  from  under  that 
which  had  been  already  turned  over,  and 
raising  it  up.  &c,  turning  it  upon  the 
first  furrow-slice,  by  means  of  which  the 
surface  soil  is  entirely  buried,  and  a  stra- 
tum of  subsoil  laid  over  it:  thus  effect- 
ing in  the  field  what  trenching  with  the 
spade  does  in  the  garden.  Trench 
ploughing  can  only  be  employed  with 
advantage  where  the  subsoil  is  naturally 
dry  and  of  good  quality,  or  where  it  has 
been  rendered  so  by  draining  and  subsoil 
ploughing;  for  bad  subsoil  brought  to 
the  surface  would  be  unfit  for  receiving 
seeds  or  plants. 

The  alteration  produced  upon  the  capa- 
bility of  land,  by  ploughing,  is  very 
great:  the  tenacity  of  soils  is  broken 
up,  the  particles  separated,  drainage  and 
aeration  more  perfect.  The  absorbent 
power  of  the  clay  is  brought  into  action, 
and  the  gaseous  matter  furnished  by  the 
atmospheric  dews  and  rain  is  more  per- 
fectly retained.  As  a  consequence  of  a 
new  surface  of  earth  being  brought  up, 
the  ammonia  carbonic  and  nitric  acids 
which  exist  in  the  air,  are  retained  and 
kept  for  the  future  use  of  the  crop.  Ma- 
nures, also,  for  the  same  reason,  are  bet- 
ter absorbed.  Worms  and  insects  are 
thrown  out,  are  thereby  exposed  to  the 
element,  and  destroyed  'in  great  number, 
which,  if  such  did  not  occur,  would  in- 
fest the  growing  crop  of  next  year,  and 
perhaps  completely  ruin  it. 

The  furrows  of  clay  soils  should  be 


pol] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


411 


turned  over  at  an  angle  of  45°,  and  the 
depth  of  the  furrow-slice  should  be  two- 
thirds  of  its  width  :  thus,  a  furrow  6  in- 
ches deep  should  be  9  inches  wide,  or  if 
8  inches  deep,  12  inches  wide.  This 
allows  the  furrows  to  lie  equally  and 
evenly.  If  the  subsoil  be  similar  to  the 
surface,  or  be  not  too  light,  ploughing 
can  hardly  be  carried  too  deep — generally 
12  inches,  for  the  usual  tillage  crops,  is  a 
depth  to  which  the  plough  may  be  gra- 
dually carried.  For  gardens  it  may  be 
carried  to  15  or  18  inches.  Whatever  is 
the  depth  of  the  surface  soil,  the  plough 
ought  to  turn  it  up  completely ;  and,  what 
is  beyond  that,  may  be  loosened  by  the 
subsoil  plough.  The  cultivator  is  used 
very  often  in  this  country  as  a  substitute 
for  the  plough.  Even  with  the  most  re- 
cent improvement  in  this  instrument, 
any  quantity  of  land  ploughed  is  a  great 
tax  on  the  strength  of  animals.  Thus,  a 
pair  of  horses  may  plough  three-fourths 
of  an  acre  of  light  soil  per  day,  and  one- 
half  of  stiff  soil.  If  the  furrow-slide  is 
9  inches,  an  acre  is  11  miles  of  furrows, 
without  turning,  equal  to  another  mile ; 
for  there  are  6,272,640  square  inches  in 
an  acre,  and  77,440  squares  of  9  inches  in 
an  acre,  and  this,  by  7040,  the  number  of 
9  inches  in  a  mile,  goes  11  times.  If  the 
slide  were  10  inches,  the  plough  would 
travel  9-9  miles,  and  if  8  inches,  12*375 
miles.  Ploughing  is,  therefore,  severe 
labor  for  men  and  horses.  In  spade 
culture,   if  a  man  turn   over  7   inches 

,      ..  AC.  .       ,  6,272,640 

each  time,  or  49  square  inches,  - — - — 


the  amount  is  equal  to  128,000  spades,  to 
be  turned  in  an  acre. 

PLUMBAGO,  or  GKAPHITE,  is  some- 
times found  in  thin,  irregular,  six-sided 
tables  ;  but  more  generally  in  scales,  or 
compact.  Specific  gravity  2.  It  consists 
of  carbon  96,  and  iron  4.  Its  most  re- 
markable depository  is  at  Borrowdale,  in 
Cumberland,  where  it  exists  in  a  bed  of 
trap.  The  chief  employment  of  plum- 
bago is  in  manufacturing  pencils  and 
crucibles  ;  the  latter  particularly,  for  the 
mint.  It  is  also  used  for  giving  a  gloss 
to  iron  stoves  and  railings,  and  for  di- 
minishing friction.  It  is  also  used  as  a 
coating  in  electro-metallurgy. 

It  occurs  crystallized  in  the  limestone 
of  Orange,  co.  N.  Y.,  and  Sussex,  co. 
N.  J.,  and  exists  in  large  fibrous  masses 
near  Roger's  Rock,  on  L.  George,  N.  Y. ; 
but  its  only  valuable  locality  in  the  United 
States  is  at  Stourbridge,  in  Worcester, 
co.  Mass.,  where  it  forms  veins  in  gneiss 
about  one  foot  wide.    It  was  worked  for- 


merly by  the  French,  was  then  neglected, 
and  has  recently  been  reopened. 

PLUSH  is  a  textile  fabric,  having  a 
sort  of  velvet  nap  or  shag  upon  one  side. 
It  is  composed  regularly  or  a  woof  of  a 
single  woollen  thread,  and  a  two-fold 
warp,  the  one,  wool  of  two  threads 
twisted,  the  other,  goat's  or  earners  hair. 
There  are  also  several  sorts  of  plush 
made  entirely  of  worsted.  It  is  manu- 
factured, like  velvet,  in  a  loom  with  three 
treadles  ;  two  of  which  separate  and  de- 
press the  woollen  warp,  and  the  third 
raises  the  hair-warp,  whereupon  the 
weaver,  throwing  the  shuttle,  passes  the 
woof  between  the  woollen  and  hair  warp ; 
afterwards,  laying  a  brass  broach  or 
needle  under  that  of  the  hair,  he  cuts  it 
with  a  knife  destined  for  that  use,  run- 
ning its  fine  slender  point  along  in  the 
hollow  of  the  guide-broach,  to  the  end 
of  a  piece  extended  upon  a  table.  Thus 
the  surface  of  the  plush  receives  its  vel- 
vety appearance.  This  stuff  is  also  made 
of  cotton  and  silk. 
POINT  NET.  (See  Lace.) 
POLISHING  METALS.  ■  The  work- 
men commence  by  preparing  the  sur- 
faces of  the  articles  ;  that  is  to  say,  it  is 
of  importance  to  remove  all  the  marks 
left  by  the  file,  the  turning  tool,  the 
scraper,  &c,  in  order  to  render  the  sur- 
faces uniform. 

This  preparation  is  effected  on  those 
metals,  which  are  not  very  hard,  by 
means  of  pumice-stone,  either  used  in 
substance  or  reduced  to  powder  and 
water ;  and  when  in  powder  applied 
upon  felt,  or  upon  slips  of  soft  wood, 
covered  with  buffalo  or  chamois  skin,  if 
the  surfaces  be  flat;  or  with  pieces  of 
soft  wood  properly  shaped,  so  as  to  pene- 
trate into  the  hollows,  and  act  upon  the 
raised  parts.  When  the  first  coarse 
marks  are  thus  removed,  they  then  pro- 
ceed to  remove  those  left  by  the  pumice- 
stone.  In  order  to  do  this,  they  employ 
finely  powdered  pumice-stone,  which 
they  grind  up  with  olive-oil,  and  employ 
it  upon  felt,  or  upon  small  pieces  of  soft 
wood,  such  as  that  of  the  willow  or  sal- 
low. It  is  important,  in  these  manipula- 
tions, to  observe  an  important  rule, 
which  is  never  to  proceed  trom  one  ope- 
ration to  another,  before  previously  wash- 
ing the  pieces  of  work  well  with  soap 
and  water,  by  means  of  a  brush,  in  order 
entirely  to  remove  the  pumice-stone, 
used  with  water,  before  employing  it  with 
oil,  and  likewise  never  to  use  those  tools 
for  succeeding  operations,  which  had 
been  used  in  preceding  ones ;  each  stage 


478 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[poi 


of  the  operation  requiring  particular  tools,  ! 
and  which   should  be   kept    in    closed 
boxes,  in  order  to  prevent  the  powders 
being  diffused  or  scattered  about  when 
not  in  use. 

After  removing  the  marks  left  by  the 
coarse  pumice-stone  and  water,  by  means 
of  finely-grounded  pumice-stone  and  oil : 
to  know  which,  we  should  wash  it  with 
soap  and  water,  and  dry  it  well  with  a 
linen  cloth :  we  must  then  examine  it 
with  a  lens  or  magnifying-glass,  to  see 
whether  any  scratches  yet  remain;  if 
not  we  may  proceed  to  the  polishing. 
The  softer  metals  are  polished  in  differ- 
ent manners,  according  to  their  size  and 
uses ;  the  larger  gold  works  are,  however, 
generally  burnished,  but  the  smaller 
gold  works  in  jewelry,  «fec,  and  those  in 
brass  for  watch-work,  are  not  burnished, 
but  polished.  The  following  are  manipu- 
lations : — After  having  removed  with 
oil-stone  powder  the  marks  of  the  file, 
&c.  they  smooth  them  with  blue  and 
grey  stones,  and  plenty  of  water :  there 
are  two  kinds  of  these  stones,  the  one 
soft  and  the  other  hard  :  the  first  argil- 
laceous schistus,  the  second  kind  schisto 
coticule ;  this  serves  to  sharpen  tools 
upon.  The  pieces  of  watch- work  are 
always  smoothened  in  this  manner, 
until  all  the  marks  disappear,  and  which 
is  known  by  washing  them  with  soap 
and  water. 

They  finally  proceed  to  polishing  with 
the  tripoli  from  Venice,  which  is  prefer- 
able to  any  other  sort,  and  is  either  finely 
ground  in  water,  or  in  olive-oil,  accord- 
ing to  the  different  cases,  for  pieces  of 
gold  work,  or  the  larger  kinds  of  jewel- 
ry articles,  and  until  they  perceive 
their  surfaces  are  become  perfectly  bril- 
liant ;  they  then  finish  them  with  tripoli, 
reduced  to  an  impalpable  powder,  and 
applied  upon  a  very  soft  brush. 

For  polishing  those  pieces  of  watch- 
work  which  are  not  to  be  gilt;  after 
smoothing  them  with  grey  or  blue-stone 
and  water,  they  polish  them  with  rot- 
ten-stone well  washed  over,  and  conse- 
quent^ very  fine,  ground  up  with  olive- 
oil,  and  finish  them  with  dry  rotten-stone. 

This  rotten-stone  is  a  kind  of  very 
light  tripoli,  but  finer  and  more  friable 
than  the  other  sorts.  It  is  found  in  Eng- 
land, and  is  highly  esteemed  for  polish- 
ing ;  it  is  of  an  ashy-grey  tint,  and 
occurs  in  thin  layers,  upon  the  compact 
carbonate  of  lime,  near  Bakewell.  The 
polishing  of  steel  is  not  executed  in  the 
same  manner  as  in  polishing  the  softer 
metals  ;  the  steel  is  not  polished  until  it 


has  been  hardened,  and  the  harder  it  is 
the  more  brilliant  will  be  its  polish. 
The  substances  above  indicated  for 
polishing  other  metals  are  not  powerful 
enough  to  attack  a  substance  so  hard  as 
this.  We  must  employ  emery  ground 
in  oil,  before  used.  Hardened  steel  is 
either  polished  flat,  like  glass,  or  cut 
into  facets,  like  a  diamond ;  conse- 
quently, the  lapidary's  mill  is  used. 
They  commence  by  smoothing  the  work 
with  rather  coarse  emery,  then  with 
finer  emery,  and  finish  with  the  finest. 
The  smoothing  being  perfected,  they 
polish  it  with  English  rouge,  tritoxide 
of  iron  and  oil,  and  finally  finish  it 
with  putty  of  tin  (peroxide  of  tin}  and 
water ;  but  if  upon  mills,  or  laps  ot  zinc.', 
then  without  the  use  of  water.  "When 
the  steel  articles  consist  of  raised  and 
hollow  work,  they  are  smoothed  and  po- 
lished with  the  same  substance ;  but  the 
instruments  are,  as  in  the  case  of  less 
harder  metals,  pieces  of  wood,  properly 
shaped,  and  employed  in  the  same  man- 
ner. The  finish  at  Sheffield  is  effected 
with  the  female  hand. 

Polishing  Ivory,  Bone,  Horn,  and  Tor- 
toise-shell. Ivory  and  bone,  either  plain 
or  ornamented ;  and  ivory  or  bone  arti- 
cles admit  of  being  turned  very  smooth, 
or,  when  filed,  may  afterwards  be  scrap- 
ed, so  as  to  present  a  good  surface.  They 
may  be  polished  by  rubbing  them  first 
with  fine  glass  paper,  and  then  with  a 

Sieceof  wet  linen  cloth  dipped  in  pow- 
ered pumice-stone ;  this  will  give  a 
very  fine  surface,  and  the  final  polish 
may  be  produced  by  washed  chalk,  or 
fine  whiting  applied  upon  another  piece 
of  cloth  wetted  with  soap-suds. 

Horn  and  Tortoise-shell.  A  very  per- 
fect surface  is  given  by  scraping  them  ; 
the  scraper  may  be  made  of  a  razor- 
blade,  the  edge  of  which  should  be  rubbed 
upon  an  oil-stone,  holding  the  blade  near- 
ly upright  all  the  while,  so  as  to  form'  an 
edge  like  that  of  a  currier's  knife ;  and 
which,  like  it,  maybe  sharpened  and  im- 
proved by  burnishing,  at  feast  as  far  as 
its  hardness  will  permit.  To  prepare  the 
work,  when  properly  scraped  for  polish- 
ing, it  is  first  to  be  rubbed  with  a  buff, 
made  of  woollen  cloth,  perfectly  free 
from  grease.  After  the  work  has  been 
made  as  smooth  as  possible  by  this 
means,  it  must  be  followed  by  another 
buff  or  bob,  on  which  washed  chalk  or 
drv  whiting  is  rubbed ;  the  comb,  or 
other  article,  is  to  be  slightly  moistened 
with  vinegar,  and  the  buff  and  whiting 
will  produce  a  fine  gloss,  which  may  be 


pot] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


419 


completed  by  rubbing  it  with  the  palm  of 
the  hand,  and  a  small  portion  of  dry  whit- 
ing or  rotten-stone. 

Polishing  Iron,  lirass,  &c.  A  beauti- 
ful surface  is  produced  upon  cast-iron, 
steel,  and  brass-works,  by  means  of 
emery  sticks,  and  others  coated  with 
crocus.  Mix  drying  linseed-oil,  in  the 
proportion  of  one-eighth  part  with 
glue,  and  coat  the  surfaces  of  pieces  of 
soft  yellow  pine,  fir,  or  deal,  without 
turpentine  or  knots,  which  are  about 
eight  inches  long,  and  five-eighths  of 
an  inch  square,  and  nicely  planed.  Lay 
on  a  coat  of  thin  glue,  and  when  that  is 
dry,  another  composed  of  glue  mixed 
with  the  emery  or  crocus,  and  then  in- 
stantly sift  over  the  wet  surface  the 
emery  or  crocus  in  powder,  by  means  of 
a  sieve.  Emery  is  employed  of  differ- 
ent degrees  of  fineness,  and  sticks  thus 
coated  with  each  may  be  used  in  suc- 
cession, to  smooth  the  work ;  and, 
lastly,  sticks  coated  with  glue  and  crocus 
are  used  to  give  the  finishing  polish. 
Such  emery  and  crocus  sticks  "are  very 
durable,  aud  are  equally  useful  on  works 
in  the  lathe,  as  well  as  upon  flat  surfaces  ; 
are  superior  to  the  glass  or  emery  papers 
ordinarily  used;  and  greatly  to  emery 
mixed  with  oil,  and  applied  upon  sticks 
in  the  common  way. 

Hindoo  Polish.  Powdered  corundum 
with  melt  lac  is  used  to  polish  all  stones, 
first  sprinkling  them  with  water. 

German  Polish.  The  wood  is  pre- 
pared with  pumice-stone  rubbed  flat, 
oiled,  and  then  rubbed  together  till 
smooth.  The  only  varnish  then  used  is 
a  solution  of  seed-lac  or  shell-lac  in 
alcohol,  the  clearest  grains  of  lac  being 
for  the  lightest  varnish.  It  is  colored 
red  with  Brazil  wood,  and  yellow  by  tur- 
meric root.  It  is  applied  with  a  rubber 
of  five  pieces  of  linen  ;  the  varnish  is  laid 
on  with  a  sponge,  and  when  soaked, 
linseed-oil  is  added,  and  the  whole  gone 
over  with  a  rubber. 

POPLIN.  Among  the  varieties  of  wo- 
ven goods  in  which  silk  and  worsted  or  silk 
and  woollen  are  used  in  combination, 
poplin  is  one  of  the  best  and  most  es- 
teemed. Tabinet  is  one  form  of  the  ma- 
terial, and  Ireland  has  been  distinguished 
for  the  excellence  of  its  poplins  and  ta- 
binets.  The  demand  is  now  small,  as 
other  kinds  of  textile  fabrics  have  lately 
been  more  in  favor;  but  the  rich  Irish 
Poplins  and  Tabinets,  though  employ- 
ing only  a  small  number  of  persons  in 
their  manufacture,  maintain  their  high 
character. 


POPPY.  See  Opium. 

PORPHYRY,  is  a  compound  rock,  hav- 
ing a  basis  in  which  the  other  contempo- 
raneous constituent  parts  are  imbedded. 
The  base  is  sometimes  claystone,  some- 
times hornstone,  sometimes  compact  feld- 
spar, jade,  pitehstone,  pearlstone,  and 
obsidian.  The  feldspar  paste  is  most  fre- 
quent. The  imbedded  parts  are  common- 
ly feldspar  and  quartz ;  the  former  in  more 
or  less  distinct  crystals.  There  are  por- 
phyries of  difterent  ages.  One  variety  is 
found  graduating  into  granite  and  gneiss ; 
but  this  does  not  possess  the  characteris- 
tics of  the  rock  in  the  highest  perfection ; 
another  is  found  in  overlying  strata,  and 
unconformable  to  other  rocks,  which  is 
the  true  porphyry.  Its  color  is  of  the  red 
or  green,  and,  when  polished,  is  valuable 
for  ornamental  work. 

PORTLAND  POWDER,  once  consid- 
ered a  speciiic  for  the  gout,  is  made  of 
equal  parts  powdered  and  mixed  of  the 
roots  of  gentian  and  birthwort,  the  tops 
and  leaves  of  germander,  ground  pine 
and  lesser  centaury. 

PORTLAND  STONE.  An  oolitic  form- 
ation found  in  Dorsetshire,England,  used 
in  building,  but  it  is  a  stone  which  readi- 
ly decavs. 

POTASH,  or  POTASSA.  This  sub- 
stance was  so  named  from  being  prepared 
for  commercial  purposes  by  evaporating  in 
iron  pots  the  lixivium  of  the  ashes  of 
wood  fuel.  In  the  crude  state  called  pot- 
ashes, it  consists,  therefore,  of  such  consti- 
tuents of  burned  vegetables  as  are  very 
soluble  in  water,  and  fixed  in  the  fire.  The 
potash  salts  of  plants  which  originally  con- 
tained vegetable  acids,  will  be  converted 
into  carbonates,  the  sulphates  will  become 
sulphites,  sulphurets,  or  even  carbonates, 
according  to  the  manner  of  incineration ; 
the  nitrates  will  be  changed  into  pure  car- 
bonates, while  the  muriates  or  chlorides 
will  remain  unaltered.  Should  quicklime  be 
added  to  the  solution  of  the  ashes,  a  corres- 
ponding portion  of  caustic  potassawill  be 
introduced  into  the  product,  with  more  or 
lesslime,  according  to  the  care  taken  in 
decanting  off  the  clear  ley  for  evaporation. 

On  this  continent,  where  timber  is  in 
many  places  an  incumbrance  upon  the 
soil,  it  is  felled,  piled  up  in  pyramids,  and 
burned,  solely  with  a  view  to  the  manu- 
facture of  potashes.  The  ashes  are  put 
into  wooden  cisterns,  having  a  plug  at  the 
bottom  of  one  of  the  sides  under  a  false 
bottom ;  a  moderate  quantity  of  water  is 
then  poured  on  the  mass,  and  some  quick- 
lime is  stirred  in.  After  standing  for  a 
few  hours,  so  as  to  take  up  the  soluble 


480 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pot 


matter,  the  clear  liquor  is  drawn  off,  eva- 
porated to  dryness  in  iron  pots,  and  final- 
ly fused  at  a  red  heat  into  compact  mass- 
es, which  are  gray  on  the  outside,  and 
pink-colored  within. 

Pearlash  is  prepared  by  calcining  pot- 
ashes upon  a  reverberatory  hearth,  till  the 
whole  carbonaceous  matter,  and  the  great- 
er part  of  the  sulphur,  be  dissipated ; 
then  lixiviating  the  mass,  in  a  cistern 
having  a  false  bottom  covered  with  straw, 
evaporating  the  clear  ley  to  dryness  in  flat 
iron  pans,  and  stirring  it  towards  the  end 
into  white  lumpy  granulations. 

The  best  pink  Canadian  potashes  con- 
tain pretty  uniformly  60  per  cent,  of  ab- 
solute potassa ;  and  the  best  pearlashes 
contain  50  per  cent. ;  alkali  in  the  former 
being  nearly  in  a  caustic  state  ;  in  the  lat- 
ter, carbonated. 

All  kinds  of  vegetables  do  not  yield  the 
same  proportion  of  potassa.  The  more 
succulent  the  plant,  the  more  it  affords,  for 
it  is  only  in  the  juices  that  the  vegetable 
salts  reside,  which  are  converted  by  inci- 
neration into  alkaline  matter.  Herbace- 
ous weeds  are  more  productive  of  potash 
than  the  graminiverous  species,  or  shrubs, 
and  these  than  trees  ;  and  for  a  like  rea- 
son, twigs  and  leaves  are  more  productive 
than  timber.  But  plants  in  all  cases  are 
richest  in  alkaline  salts  when  they  have 
arrived  at  maturity.  The  soil  in  which 
they  grow  also  influences  the  quantity  of 
saline  matter. 

The  following  Table  exhibits  the  aver- 
age product  in  potassa  of  several  plants : — 

In  1000  parts.  Potassa. 

Pine  of  fir 0-45 

Poplar 0-T5 

Trefoil 0-75 

Beechwood 1-45 

Oak J-53 

Boxwood 2-26 

Willow 2-35 

Elm  and  maple 3-90 

Wheat  straw 3-90 

Barb  of  oak  twigs 4-20 

Thistles 5-00 

Flax  stems 5-00 

Small  rushes 5-08 

Vine  shoots 5-50 

Barley  straw 5-80 

Dry  beech  bark 6-00 

Fern 6-26 

Large  rush 7-22 

Stalk  of  maize 17-50 

Bastard  chamomile  (Anthemis  cotula,  L  )  19-60 

Bean  stalks 20-00 

Sunflower  stalks 20-00 

Common  nettle 25-08 

Vetch  plant 27-50 

Thistles  in  full  growth 85-37 

Dry  straw  of  wheat  before  earing 47-00 

Wormwood 78-00 

Fumitory 79-00 


Stalks  of  tobacco,  potatoes,  chestnuts, 
chestnut  husks,  broom,  heath,  furze,tansy, 
sorrel,  vine  leaves,  beet  leaves,  orach,  and 
many  other  plants,  abound  in  potash 
salts. 

The  purification  of  pearlash  is  founded 
upon  the  fact  of  its  being  more  soluble  in 
water  than  the  neutral  salts  which  debase 
it.  Upon  any  given  quantity  of  that  sub- 
stance, in  an  iron  pot,  let  one  and  a  half 
times  its  weight  of  water  be  poured,  and 
let  a  gentle  heat  be  applied  for  a  short 
time.  When  the  whole  has  again  cooled, 
the  bottom  will  be  incrusted  with  the  salts, 
while  a  solution  of  nearly  pure  carbonate 
of  potash  will  be  found  floating  above, 
which  may  be  drawn  off  clear  by  a  syphon. 
The  salts  may  be  afterwards  thrown  upon 
a  filter  of  gravel.  If  this  ley  be  diluted 
with  6  times  its  bulk  of  water  mixed  with 
as  much  slaked  lime  as  there  was  pearlash 
employed,  and  the  mixture  be  boiled  for 
an  hour,  the  potash  will  become  caustic, 
by  giving  up  its  carbonic  acid  to  the  lime. 
If  the  clear  settled  lixivium  be  now  sy- 
phoned off,  and  concentrated  by  boiling  in 
a  covered  iron  pan,  till  it  assumes  the  ap- 
pearance of  oil,  it  will  constitute  the  com- 
mon caustic  of  the  surgeon,  the  potassa 
fuza  of  the  shops.  But  to  obtain  potassa 
chemically  pure,  recourse  must  be  had  to 
the  bicarbonate,  nitrate,  or  tartrate  of  pot- 
assa, salts  which,  when  carefully  crystal- 
lized, are  exempt  from  any  thing  to  ren- 
der the  potassa  derived  from  them  im- 
pure. The  bicarbonate  having  been  gently 
ignited  in  a  silver  basin,  is  to  be  dissolved 
in  6  times  its  weight  of  water,  and  the 
solution  is  to  be  boiled  for  an  hour,  along 
with  one  pound  of  slaked  lime  for  every 
pound  ot  the  bicarbonate  used.  The 
whole  must  be  left  to  settle  without  con- 
tact of  air.  The  supernatant  ley  is  to  be 
drawn  off  by  a  syphon,  and  evaporated 
in  an  iron  or  silver  vessel  provided  with 
a  small  orifice  in  its  close  cover  for  the  es- 
cape of  the  steam,  till  it  assumes,  as  above, 
the  appearance  of  oil,  or  till  it  be  nearly 
redhot.  The  fused  potassa  is  now  poured 
out  upon  a  bright  plate  of  iron,  cut  into 
pieces  as  soon  as  it  concretes,  and  put  up 
immediately  in  a  bottle  furnished  with  a 
well-ground  stopper.  It  is  hydrate  of 
potassa,  being  composed  of  1  atom  of 
potassa  48,  +  1  atom  of  water  9,  =  57. 

A  pure  carbonate  of  potassa  may  be  also 
prepared  by  fusing  pure  nitre  in  an  earth- 
en crucible,  and  projecting  charcoal  into 
it  by  small  bits  at  a  time,  till  it  ceases  to 
cause  deflagration.  Or  a  mixture  of  10 
parts  of  nitre  and  1  of  charcoal  may  be 
deflagrated  in  small  successive  portion* 


pot] 


CYCLOPEDIA    OP   THE    USEFUL    ARTS. 


481 


in  a  redhot  deep  crucible.  When  a  mix- 
ture of  2  parts  of  tartrate  of  potassa,  or 
crystals  ot  tartar,  and  1  of  nitre,  is  defla- 
grated, pure  carbonate  of  potassa  remains 
mixed  with  charcoal,  which  by  lixiviation, 
and  the  agency  of  quicklime,  will  afford 
a  pure  hydrate.  Crystals  of  tartar  calcin- 
ed alone  yield  also  a  pure  carbonate. 

Caustic  potassa  may  be  crystallized ; 
but  in  general-it  occurs  as  a  white  brittle 
substance  of  spec.  grav.  1.708,  which 
melts  at  a  red  heat,  evaporates  at  a  white 
heat,  deliquesces  into  a  liquid  in  the  air, 
and  attracts  carbonic  acid  ;  is  soluble  in 
water  and  alcohol,  forms  soft  soaps  with 
fat  oils,  and  soapy-looking  compounds 
with  resins  and  wax;  dissolves  sulphur, 
some  metallic  sulphurets,  as  those  of 
antimony,  arsenic,  &c,  as  also  silica, 
alumina,  and  certain  other  bases ;  ana 
decomposes  animal  textures,  as  hair,wool, 
silk,  horn,  skin,  &c.  It  should  never  be 
touched  with  the  tongue  or  the  fingers. 

The  only  certain  way  of  determining 
the  quantity  of  free  potassa  in  any  solid 
or  liquid,  is  from  the  quantity  of  a  dilute 
acid  of  known  strength  which  it  can  sa- 
turate. 

The  hydrate  of  potassa,  or  its  ley,  often 
contains  a  notable  quantity  of  carbonate, 
the  presence  of  which  may  be  detected  by 
lime  water,  and  its  amount  be  ascertained 
by  the  loss  of  weight  which  it  suffers, 
when  weighed  portion  of  the  ley  is  pour- 
ed into  a  weighed  portion  of  dilute  sul- 
phuric acid  poised  in  the  scale  of  a  balance. 

Carbonate  of  potassa  is  composed  of  48 
parts  of  base,  and  22  of  acid,  according 
to  most  Britsh  authorities ;  or,  in  100 
parts,  of  68-57  and  31-43 ;  but  according 
to  Berzelius,  of  68-09  and  31-91. 

Carbonate  of  potassa,  as  it  exists  asso- 
ciated with  carbon  in  calcined  tartar, 
passes  very  readily  into  the  Bicarbonate ,on 
being  moistened  with  water,  and  having 
a  current  of  carbonic  acid  gas  passed 
through  it.  The  absorption  takes  place 
so  rapidly,  that  the  mass  becomes  hot,  and 
therefore  ought  to  be  surrounded  with 
cold  water.  The  salt  should  then  be  dis- 
solved in  the  smallest  quantity  of  water 
at  120°  F.,  filtered,  and  crystallized. 

The  exports  of  potash  for  the  years 
1847-48  was— in  1847,  618,000  dollars: 
in  1848,  466,477.  The  quantity  in  value 
which  came  to  the  Hudson  Eiver,  on  all 
the  canals,  was— in  1846,  ashes,  barrels, 
46,812,  value,  1,076,904;  in  1847,  ashes, 
barrels,  37,538,  value,  1,135,288. 

POTATO.  The  tubers  of  the  Sola- 
tium tuberosum.— -The  potato,  which  is  at 
present  to  be  met  with  everywhere  in 


Europe,  and  forms  the  principal  part 
of  the  food  of  a  large  proportion  ot  its 
inhabitants,  was  entirely  unknown  in 
that  quarter  of  the  worfd  till  the  latter 
part  of  the  16th  centurv.  It  is  a  rative 
of  America  ;  but  whether  of  both  di- 
visions of  this  continent  is  doubtful. 
Some  authors  affirm  that  it  was  first  intro- 
duced into  Europe  by  Sir  John  Hawkins, 
in  1545;  others  that  it  was  introduced  by 
Sir  Francis  Drake,  in  1578  ;  and  others, 
again,  that  it  was  for  the  first  time  brought 
to  England  from  Virginia  by  Sir  Walter 
Raleigh,  in  1586.  But  this  discrepancy 
seems  to  have  arisen  from  confounding 
the  common  or  Virginian  potato  (the 
Solatium  tvheromm  of  Linnaeus)  with  the 
sweet  potato  (Convolvulus  battatus).  The 
latter  was  introduced  into  Europe  long 
before  the  former,  and  it  seems  most 
probable  that  it  was  the  species  brought 
from  New  Grenada  by  Hawkins.  Sweet 
potatoes  require  a  warm  climate,  and  do 
not  succeed  in  Eugland ;  they  were,  how- 
ever, introduced  there  in  considerable 
quartities,  during  the  16th  century,  from 
Spain  and  the  Canaries,  and  were  sup- 
posed to  have  some  rather  peculiar  prop- 
erties. The  kissing  comfits  of  Faistaff, 
and  such  like  confections,  were  princi- 
pally made  of  battatas  and  eringo  roots. 
Potatoes  were  at  first  cultivated  by  a  very 
few,  and  were  looked  upon  as  a  great 
delicacy.  In  a  manuscript  account  of  the 
household  expenses  ot  Queen  Anne, 
wife  of  James  I.,  who  died  in  1618,  and 
which  is  supposed  to  have  been  written 
in  1613,  the  purchase  of  a  small  quantity 
of  potatoes  is  mentioned  at  the  price  of 
2s.  a  pound.  Previously,  however,  to 
1684,  they  were  raised  only  in  the  gar- 
dens of  the  nobility  and  gentry  ;  but  in 
that  year  they  were  planted  for  the  first 
time,  in  the  open  fields  in  Lancashire — a 
county  in  which  they  have  long  been 
very  extensively  cultivated. 

Potatoes,  it  is  commonly  thought,  were 
not  introduced  into  Ireland  till  1610, 
when  a  small  quantity  was  sent  by  Sir 
Walter  Raleigh  to  be  planted  in  a  gardeu 
in  his  estate  in  the  vicinity  of  Youghal 
Their  cultivation  extended  far  more  readi- 
ly than  in  England  ;  and  have  long  fur- 
nished from  three-fifths  to  four-fifths  of 
the  entire  food  of  the  people  of  Ireland  ! 

The  extension  of  the  potato  cultivation 
has  been  particularly  rapid  during  the 
last  forty  years.  The  quantity  that  is 
now  raised  in  Scotland  is  supposed  to  be 
from  10  to  12  times  as  great  as  the  quan- 
tity raised  in  it  at  the  end  of  the  Ameri- 
can war  •  and  though  the  increase  in 
I 


482 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[pot 


England  has  not  been  nearly  so  great  as 
in  Scotland,  it  has  been  greater  than  at 
any  previous  period  of  equal  duration. 
The  increase  through  Europe  has  been  ; 
similar.    Potatoes  are  now  very  largely  j 
cultivated  in  France,  Italy,  and  Genua-  | 
ny  ;  and,  with  the  exception  of  the  Irish,  j 
the  Swiss  have  become  their  greatest  con-  j 
sumers.      They    were    introduced    into  i 
India  some  sixty  or  seventy  years  ago ;  | 
and  are  now  successfully  cultivated  in 
Bengal,  and  have  been  introduced  into 
the  Madras  provinces,  Java,  the  Philip- 
pines, and  China.     But  the  common  po- 
tato does  not  thrive  within  the  tropics, 
unless  it  be  raised  at  an  elevation  of  3000 
or  4000  feet  above  the  level  of  the  sea,  so 
that  it  can  never  come  into  very  general 
use  in  these  regions.    This,  however,  is 
not  the  case  with  the  sweet  potato,  which 
has  also  been  introduced   into  tropical 
Asia ;  and  with  such  success,  that  it  al- 
ready forms  a  considerable  portion  of 
the  food  of  the  people  of  Java,  and  some 
other  countries.    So  rapid  an  extension 
of  the  taste  for,  and  the  cultivation  of  an 
exotic,  has  no  parallel  in  the  history  of 
industry  ;  it  has  bad,  and  will  continue 
to  have,  the  most  powerful  influence  on 
the  condition  of  mankind. 

The  sweet  potato  is  the  tuber  of  the 
Convolvulus  battatus.  It  is  a  root  of  gene- 
ral growth,  and  much  cultivated  in  the 
middle  sections  of  the  United  States. 
Since  the  repeated  failures  and  disease  of 
the  common  potato,  much  attention  has 
been  turned  to  the  raising  this  crop  in 
New  Jersey  and  Pennsylvania.  They 
are  generally  planted  in  hills  or  drills  on 
well  manured  land,  and  are  fit  for  gather- 
ing when  the  vines  are  dead.  There  are 
numerous  varieties  of  the  sweet  potato — 
as  the  white,  red,  yellow,  &c.  Fine 
crops  are  generally  raised  in  the  South- 
ern States.  The  general  average  crop  of 
South  Carolina  is  50  bushels  per  acre, 
though  near  Charleston,  100,  and  even 
150  bushels  have  been  raised.  Similar 
crops  are  raised  in  Georgia  and  Alabama. 
In  Louisiana  100  bushels  are  a  fair  crop. 
It  is  grown  equally  with  the  common 
potato  in  Kentucky  and  Tennessee,  and 
its  cultivation  is  extending  in  Ohio.  Over 
the  entire  States  its  cultivation  is  extend- 
ing. It  is  hardier  than  the  common  po- 
tato, and  has  not  been  subject  to  what 
has  been  called  the  potato  rot. 

Bryant,  in  his  "  "What  I  saw  in  Cali- 
fornia," describes  a  root  which  he  met 
with  on  the  great  prairie,  and  which  he 
calls  prairie  potato,  which  he  considers 
in  many  respects  superior  to  the  common 


potato,  and  which  it  might  be  useful  to 
introduce  into  cultivation.  It  is  not 
grown  in  Europe,  for  food. 

Potatoes  are  not  as  much  used  in  this 
country  as  in  Europe,  yet  the  crops  raised 
over  the  whole  country  appear  to  be  very 
great.  Potatoes  are  grown  more  abun- 
dantly in  Canada  and  the  Northern  States, 
than  in  the  Middle  and  Southern  States. 
The  produce  there  is  also  greater,  but  the 
tubers  are  more  subject  to  the  rot.  In 
Maine  potatoes  are  raised  largely  for 
export.  The  estimate  of  the  potato  crop 
in  1848  over  32  States  was  equal  to 
114,475,000  bushels,  of  which  the  State 
of  New  York  grew  27,000,000  bushels. 
The  disease  and  failure  of  this  crop  of 
late  years  has  been  a  great  drawback  to 
its  more  extensive  cultivation.  The  crop 
varies  from  50  to  200  bushels  per  acre. 

According  to  Dr.  Dobereiner,  the  fol- 
lowing is  the  chemical  composition  of  po- 
tatoes obtained  from  the  seed. 

Potatoes  From  From 

from  Albert.        Kriiuse.  Greger. 

Water 714.4  756.2  810.9 

Starch 115.9  110.5  107.0 

Fibrine 70.9  52.5  50.0 

Substances  solu- 
ble in  water. .     98.8  80.8  32.1 

1000.0         1000.0         1000.0 

The  following  analysis  by  Dobereiner, 
is  given  of  a  large  sort  grown  in  the  year 
1845. 

Water  740.9 

Starch 120.0 

Fibrine 48.9 

Albumen  )                                      qq  o 
Guru         S 

1.0000 
From  other  analyses,  it  appears  that, 
of  this  valuable  root,  72-6  parts  in  100 
are  water,  15  starch,  7  fibre,  or  gluten, 
and  5-4  albumen,  and  mucilage.  Two 
flour  and  1  potatoes  make  excellent 
bread.  The  starch  is  superior  to  wheaten 
starch.  With  some  gum  tragacanth  it 
is  commonly  sold  for  arrow-root,  and, 
perhaps,  is  its  equal. 

In  100  lbs.  ol  potatoes,  only  25  parts 
are  solid,  or  nutritive,  while  the  remain- 
ing 75  consist  of  liquid.  It  contains, 
also,  a  dark  acid  substance,  and  it  is 
highlv  important  to  get  rid  of  this,  which 
im.y  be  accomplished  by  repeated  wash- 
ings, after  the  root  is  grated.  The  nutri- 
tive parts  of  the  potato  consist— 1,  of 
flour  and  starch  ;  and  2,  of  fibre.  These, 
when  the  potatoes  are  grated,  can  bo 
separated  by  a  common  strainer.  The 
flour,  which  will  be  accumulated  at  the 


pot] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


483 


bottom  of  the  tub,  must  be  repeatedly 
washed,  to  clear  it  of  the  acid  substance 
with  which  it  is  impregnated.^ 

It  can  be  converted  into  a  jelly,  in  the 
same  manner  as  arrow-root.  For  that 
purpose,  it  mnst  be  moistened  with  cold 
water,  then  put  into  a  bowl,  and  boiling 
water  gradually  poured  on  it,  constantly 
stirring  it  with  a  spoon,  for  a  few  min- 
utes, till  the  jelly  is  formed.  It  will  be 
improved  by  a  little  salt,  or  a  little  sugar, 
before  the  boiling  water  is  poured  on  it. 
A  wholesome  and  nourishing  food  is 
thus  produced,  which,  with  the  addition 
of  n  little  milk  is  extremely  palatable. 

The  quantity  of  flour,  or  starch,  in  a 
potato  differs  considerably,  according  to 
the  sort,  and  the  season.  It  varies  from 
a  fourth  to  a  seventh  part  of  the  weight 
of  the  root.  In  regard  to  the  fibrous 
part,  it  is  a  most  valuable  article  of  food, 
whether  dried  for  horses,  or  boiled  for 
cows  and  pigs. 

POTATO  STARCH  may  be  roughly 
made  thus :  Put  a  pound  and  a  quarter  o"f 
potatoes,  grated  through  a  common  tin 
bread  grater,  into  a  pan  of  water,  and 
stir  with  a  wooden  spoon,  and  as  soon  as 
the  pulpy  matter  has  subsided,  the  dis- 
colored water  is  poured  off",  and  clean 
water  added,  and  the  mass  again  stirred 
up.  When  it  has  settled  a  second  time, 
the  water  is  poured  off  by  a  gentle  incli- 
nation of  the  vessel,  and  the'  process  re- 
})eated  till  the  water  passed  off  is  color- 
ess.  Three  washings  are  sufficient.  The 
residue  is  turned  out  of  the  pan,  and 
dried  in  the  air,  and  it  produces  four 
ounces  of  very  fine  white  flour,  or  one- 
fifth  of  the  original  weight  of  the  pota- 
toes. It  may  be  used  as  a  substitute  for 
arrow-root,  for  years.  A  bread-grater  is 
the  only  instrument  necessary. 

Potato  flour,  and  Arrow-root  flour. — 
Potato  flour  may  be  known  from  arrow- 
root flour,  by  rubbing  a  little  of  it  be- 
tween the  finger  and  thumb,  when  it  will 
be  observed  that  the  potato  flour  is  softer 
to  the  touch,  and  more  shining  to  the 
siffht,  than  arrow-root. 

Size  from  Potatoes.— Starch  of  potatoes, 
quite  fresh,  and  washed  only  once,  may 
be  employed  to  make  size ;  which,  mixed 
with  chalk,  and  diluted  in  a  little  water, 
forms  a  very  beautiful  and  good  white 
for  ceilings.  This  size  has  no  smell,  and 
is  more  durable. 

>  Potato  starch  is  manufactured  exten- 
sively in  this  country,  in  Maine.     The 
following  account  of  a  starch  manufacto- 
ry in  Michigan,  at  Almont,  Lopez  coun-  | 
ty,  will  illustrate  the  mode  in  which  it  is  ! 


usually  made  here.  It  is  probably  the 
largest  establishment  of  the  kind  in  the 
United  States,  and  is  owned  by  a  gentle- 
man who  is  also  interested,  it  is  said,  in 
two  others  in  Vermont.  It  is  quoted 
from  the  Patent  Office  Report. 

"  The  factory  is  214  feet  long  and  40 
wide,  including  an  L.  The  main  build- 
ing is  134  feet  long,  14  of  which  are  used 
for  an  engine  room,  and  is  two  stories 
high.  The  lower  part  has  64  tubs,  hold- 
ing about  600  gallons  each,  giving  a  total 
of  28,400  gallons.  The  L  part  is  80  feet 
long  by  40,  of  brick,  one  and  a  half  sto- 
ries high,  for  a  potato  bin.  Loaded 
teams  drive  up  a  platform  into  the  second 
story,  and  following  a  circle,  13  teams 
can  unload  at  a  time,  through  a  trap  door 
over  the  bin,  which  is  calculated  to  hold 
40,000  bushels.  One  hundred  and  thirty 
loads  have  been  received  in  a  day,  mak- 
ing a  total  of  4000  bushels. 

"  In  the  second  story  of  the  principal 
building  is  an  oven  100  feet  long  by  18 
wide,  for  drying  the  starch  ;  or  rather,  I 
should  say,  an  oven  of  200  feet  by  9,  as 
there  is  a  division  in  the  centre,  with 
doors  some  ten  feet  apart.  In  the  oven 
there  arc  sets  of  pans,  one  above  the 
other,  which  can  be  turned  at  pleasure. 
It  is  heated  from  the  steam  works,  and 
conductors  of  heat  are  carried  in  tin 
pipes  all  over  the  building. 

"  The  potatoes  are  shovelled  from  the 
bin  into  a  hopper,  where  there  is  water 
constantly  running  into  it,  and  where 
they  are  as  thoroughly  washed  by  ma- 
chinery as  a  cook  could  do  it  for  your 
dinner.  Then,  by  the  action  of  the  ma- 
chinery, they  are  separated  from  the  dirt, 
stones,  and  sticks,  and  pass  on  to  two 
cylinder  graters,  at  the  rate  of  100  bush- 
els an  hour.  From  the  graters,  by  the 
action  of  the  machinery,  they  go  into  the 
sieve,  that  separates  the  starch  from  the 

f>otato.  The  pulp  then  passes  into  four 
arge  cisterns,  and  there  again  machinery 
pumps  it  into  the  64  large  tubs  or  cis- 
terns, before  alluded  to,  for  settling. 
Then  the  water  is  drawn  off*,  and  the 
starch,  by  a  forcing  pump,  is  carried  into 
the  second  story,  and,  when  settled,  put 
into  the  oven  I  have  before  spoken  of, 
which  is  calculated  to  bake  a  day's 
work,  being  the  starch  from  1000  bushels 
or  60,000  lbs.  of  potatoes.  The  starch  is 
packed  in  casks  and  shipped  east.  The 
cost  of  the  factory  is  $12,000. 

"Considerable  starch  was  made  in  the 
season  of  1846,  but  the  rotting  of  some 
30,000  bushels  that  fall  curtailed  the 
quantity  anticipated.     This  large  quan- 


484 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pot 


tity  of  the  raw  material  was  thrown 
away.  It  served  to  feed  many  cattle  and 
hogs  of  the  neighborhood  for  some 
months.  The  pulp  remaining  as  worth- 
less is  used  in  fattening  hogs,  which  the 
proprietor  has  in  a  yard  adjoining. 

"  The  factory  price  for  potatoes  is  ten 
cents  a  bushel.  The  owner  has  contract- 
ed with  various  farmers  to  the  amount 
of  400  acres.  The  average  number  of 
bushels  raised  in  the  year  1846  on  an 
acre,  was  275.  Allowing  the  same  this 
year,  it.  will  amount  to  over  100,000  bush- 
els ;  but  this  is  not  half  the  quantity 
wanted.  Farmers  are  unwilling  to  con- 
tract, fearing  the  rot.  Present  indica- 
tions are  good  for  the  crop.  All  varie- 
ties are  used — even  the  Rohan. 

"It  takes  the  fall  and  winter  to  use 
up  the  potatoes  ;  then  wheat  and  corn 
are  used  for  the  same  purpose.  The 
quantity  made  from  the  potato  per  year 
will  not  be  far  from  1,000,000  lbs.  or  500 
tons.  It  sells  for  $5  a  hundred  in  New 
York." 

POTSTONE.  A  tough  variety  of  stea- 
tite, sometimes  manufactured  into  culi- 
nary vessels. 

POTTERY,  PORCELAIN.  In  refer- 
ence to  chemical  constitution,  there  are 
only  two  genera  of  baked  stoneware. 
The  first  consists  of  a  fusible  earthy  mix- 
ture, along  with  an  infusible,  which  when 
combined  are  susceptible  of  becoming 
semi-vitrified  and  translucent  in  the  kiln. 
This  constitutes  porcelain  or  china-ware ; 
which  is  either  hard  and  genuine,  or  ten- 
der and  spurious,  according  to  the  quali- 
ty and  quantity  of  the  fusible  ingredient. 
The  second  kind  consists  of  an  infusible 
mixture  of  earths,  which  is  refractory-  in 
the  kiln,  and  continues  opaque.  This  is 
pottery,  properly  so  called ;  but  it  compre- 
hends several  sub-species,  which  gradu- 
ate into  each  other  by  imperceptible 
shades  of  difference.  To  this  head  be- 
long earthenware,  stoneware,  flintware, 
fayence,  delftware,  iron-stone,  china,  &c. 

The  earliest  attempts  to  make  a  com- 
pact stoneware,  with  a  painted  glaze, 
seem  to  have  originated  with  the  Arabi- 
ans in  Spain,  about  the  9th  century,  and 
to  have  passed  thence  into  Majorca,  in 
which  island  they  were  carried  on  with 
no  little  success.  In  the  14th  century, 
these  articles,  and  the  art  of  imitating 
them  were  highly  prized  by  the  Italians, 
under  the  name  of  Majolica,  and  porcela- 
na,  from  the  Portuguese  word  for  a  cup.  I 
The  first  fabric  of'stoneware  possessed  j 
by  them  was  erected  at  Faycnza,  in  the 
ecclesiastical   state,  whence"  the  French  I 


term  fayence  is  derived.  The  body  of 
the  ware  was  usually  a  red  clay,  and  the 
glaze  was  opaque,  being  formed  of  tho 
oxydes  of  lead  and  tin,  along  with  potash 
and  sand.  Bernhard  de  Palissy,  about  the 
middle  of  the  16th  century,  manufac- 
tured the  first  white  fayence,  at  Saintes, 
in  France ;  and  not  long  afterwards  the 
Dutch  produced  a  similar  article,  of  sub- 
stantial make,  under  the  name  of  delft- 
ware, and  delft  porcelain,  but  destitute  of 
those  graceful  forms  and  paintings  for 
which  the  ware  of  Fayenza  was  dis- 
tinguished. Common  fayence  may  be, 
therefore,  regarded  as  a  strong,  well- 
burned,  but  rather  coarse-grained  kind 
of  stoneware. 

It  was  in  the  17th  century  that  a  small 
work  for  making  earthenware  of  a  coarse 
description,  coated  with  a  common  lead 
glaze,  was  formed  at  Burslem,  in  Staf- 
fordshire, which  may  be  considered  as 
the  germ  of  the  vast  potteries  now  es- 
tablished in  that  county.  The  manufac- 
ture was  improved  about  the  year  1690, 
by  two  Dutchmen,  the  brothers  Elers, 
who  intoroduced  the  mode  of  glazing 
ware  by  the  vapor  of  salt,  which  they 
threw  by  handiuls  at  a  certain  period 
among  the  ignited  goods  in  the  kiln. 
But  these  were  rude,  unscientific,  and 
desultory  efforts.  It  is  to  the  late  Josiah 
Wedgewood,  Esq.,  of  England,  that 
the  world  at  large  is  mainTy  indebted 
for  the  great  modern  advancement  of  the 
ceramic  art. 

This  country  contains  all  the  materials 
for  establishing  a  perfect  manufacture  ; 
but  as  yet  little  has  been  done  except  in 
the  production  of  coarse  articles.  The  bet- 
ter kind  of  pottery,  is  made  of  an  artificial 
mixture  of  alumina  and  silica  ;  the  for- 
mer obtained  in  the  form  of  a  fine  clay, 
from  Devonshire  in  England,  chiefly ;  and 
the  latter  consisting  "of  chert  or  flint, 
which  is  heated  red-hot,  quenched  in  wa- 
ter, and  then  reduced  to  powder.  Each 
material,  carefully  siftea,  is  diffused 
through  water,  mixed  by  measure,  and 
brought  to  a  due  consistency  by  evapo- 
ration :  it  is  then  highly  plastic,  and 
formed  upon  the  potter's  wheel  and 
lathe  into  various  circular  vessels,  or 
moulded  into  other  forms,  which,  af- 
ter having  been  dried  in  a  warm  room, 
are  inclosed  in  baked  clay  cases  re- 
sembling bandboxes,  and  .  called  teg- 
gar  t  ;  these  are  ranged  in  the  kiln  so  as 
nearly  to  fill  it,  leaving  only  space  enough 
for  the  fuel  ;  here  the  ware  is  kept  red- 
hot  for  a  considerable  time,  and  thus 
brought  to  the  state  of  biscuit.    This  is 


pot] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


485 


afterwards  glazed,  which  is  done  by  dip- 
ping the  biscuit-ware  into  a  tub  contain- 
ing a  mixture  of  about  60  parts  of  li- 
tharge, 10  of  clay,  and  20  of  ground  flint, 
diffused  in  water,  to  a  creamy  consist- 
ence ;  and  when  taken  out  enough  ad- 
heres to  the  piece  to  give  an  uniform 
glazing  when  again  heated.  The  pieces 
are  then  again  packed  up  in  the  seggars, 
with  small  bits  of  pottery  interposed  be- 
tween each,  and  fired  in  a  kiln  as  before. 
The  glazing  mixture  fuses  at  a  very 
moderate  heat,  and  gives  an  uniform 
glossy  coating,  which  finishes  the  pro- 
cess when  it  is  intended  for  common 
white  ware. 

The  patterns  upon  ordinary  porcelain, 
which  are  chiefly  m  blue,  in  consequence 
of  the  facility  of  applying  cobalt,  are 
generally  first  printed  off  upon  paper, 
which  is  attached  to  the  plate  or  other 
article  while  in  the  state  ol  biscuit ;  the 
color  adheres  permanently  to  the  surface 
when  heat  is  properly  applied  :  other 
mineral  colors,  such  as  the  oxides  of 
chrome  and  manganese,  are  also  occa- 
sionally employed  in  the  same  way. 

The  manufacture  of  porcelain  is  a 
more  refined  branch  of  art ;  the  mate- 
rials are  selected  with  the  greatest  cau- 
tion, it  being  necessary  that  the  com- 
pound should  remain  perfectly  white  af- 
ter exposure  to  heat ;  it  is  also  required 
that  it  should  endure  a  very  high  tempe- 
rature without  fusing,and  at  the  same  time 
acquire  a  semivitreous  texture,  and  a  pe- 
culiar degree  of  translucency  and  tough- 
ness. These  qualities  are  united  in  some 
of  the  oriental  porcelain,  or  China,  and 
in  some  of  the  old  Dresden  ;  but  they 
are  rarely  found  coexistent  in  that  of 
modern  European  manufacture.  Some 
of  the  French  and  English  porcelain,  es- 
pecially that  made  at  Sevres  and  Wor- 
cester, is  extremely  white,  and  duly 
translucent ;  but  it  'is  more  apt  to  crack 
by  sudden  changes  of  temperature ; 
more  brittle,  and  "consequently  requires 
to  be  formed  into  thicker  and  heavier 
vessels  ;  and  more  fusible  than  the  finest 
porcelains  of  Japan  and  China. 

The  colors  employed  in  painting  porce- 
lain are  the  same  metallic  oxides  used 
for  coloring  glass,  and  in  all  the  more 
delicate  patterns  they  are  laid  on  with  a 
camel-hair  pencil,  and  generally  previ- 
ously mixed  with  a  little  oil  of  turpen- 
tine. Where  several  colors  are  used, 
they  often  require  various  temperatures 
for  their  perfection  ;  in  which  case  those 
that  bear  the  highest  heat  are  first  ap- 
plied,  and    subsequently   those    which 


are  brought  out  at  lower  temperatures. 
This  art  of  painting  on  porcelain,  or  in 
enamel,  is  ot  the  most  delicate  descrip- 
tion :  much  experience  and  skill  are  re- 
quired in  it,  and  with  every  care  there 
are  frequent  failures ;  hence  it  is  attend- 
ed with  considerable  expense.  The  gild- 
ing of  porcelain  is  generally  performed 
by  applying  finely  divided  gold  mixed 
with  gum-water  and  borax  ;  upon  the 
application  of  heat  the  gum  burns  off, 
and  the  borax  vitrifying  upon  the  surface 
causes  the  gold  firmly  to  adhere  ;  it  is 
afterwards  burnished. 

In  the  manufacture  of  various  kinds  of 
pottery  employed  in  the  chemical  labor- 
atory, and  especially  in  regard  to  cruci- 
bles, many  difficulties  occur  ;  and  many 
requisites  are  necessary,  which  cannot  be 
united  in  the  same  vessel.  To  the  late 
Mr.  Wedgewood  we  are  indebted  for 
vast  improvements  in  this  as  well  as  in 
other  branches  of  the  art.  Crucibles 
composed  of  one  part  of  pure  clay  mixed 
with  about  three  parts  of  coarse  and 
pure  sand,  slowly  dried  and  annealed,  re- 
sist a  very  high  temperature  without  fu- 
sion, and  generally  retain  metallic  sub- 
stances ;  but  where  the  metals  are  suf- 
fered to  oxidize,  there  are  few  which  do 
not  act  upon  any  earthen  vessel,  and 
some  cause  its  rapid  fusion,  as  the  ox- 
ides of  lead,  bismuth,  &c.  Where  sa- 
line fluxes  are  used,  the  best  crucibles 
will  always  suffer ;  but  platinum  may  oft- 
en be  employed  in  these  cases,  and  the 
chemist  is  thus  enabled  to  combat  many 
difficulties  which  were  nearly  insur- 
mountable before  this  metal  was  thus  ap- 
plied. Whenever  silica  and  alumina  are 
blended  as  in  the  mixture  of  clay  and 
sand,  the  compound  softens,  and  the  ves- 
sel loses  its  shape  when  exposed  to  a  long 
continued  white  heat,  and  this  is  the 
case  with  the  Hessian  crucibles  :  conse- 
quently, the  most  refractory  of  all  ves- 
sels are  those  made  entirely  of  clay, 
coarsely-powdered  burned  clay  being 
used  as  a  substitute  for  the  sand.  Such 
a  compound  resists  the  action  of  saline 
fluxes  longer  than  any  other,  and  is 
therefore  used  for  the  pots  in  glass  fur- 
naces. A  Hessian  crucible  lined  with 
purer  clay  is  rendered  much  more  reten- 
tive ;  and  a  thin  china  cup,  or  other 
dense  porcelain,  resists  the  action  of  sa- 
line matters  in  fusion  for  a  considerable 
time.  Plumbago  is  a  very  good  material 
for  crucibles,  and  applicable  to  many 
purposes  ;  when  mixed  with  clay  it 
forms  a  very  difficultly  fusible  compound, 
and  is  protected  from  the  action  of  the 


486 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[potj 


air  at  high  temperatures  :  it  is  well  cal- 
culated for  small  table  furnaces. 

There  are  three  kind  of  glazes  in  gene- 
ral use — one  for  the  common  pipe  clay 
ware,  another  for  the  finer  kind,  and  a 
third  for  the  ornamental  kind.  The 
common  glaze  is  composed  of  fifty-three 
parts  white  lead,  sixteen  parts  Cornish 
stone,  thirty-six  of  ground  flints,  four 
of  flint  glass.  These  compositions  are 
ground  with  water  into  a  thin  paste. 
Another  is  twenty  parts  of  flint  glass, 
six  of  flints,  two  of  nitre,  and  one  of  bo- 
rax. This  is  mixed  together,  and  twenty 
parts  of  it  are  ground  with  twenty-six 
parts  of  feldspar,  twenty  of  white  lead, 
six  of  ground  flint,  four  of  chalk,  nine 
of  oxide  of  tin  and  a  small  quantity  of 
the  oxide  of  cobalt. 

Another  glaze  consists  of  twenty  parts 
of  flint  glass,  six  of  flints,  two  of  nitre, 
one  of  borax.  These  must  be  calcined  to- 
gether, and  to  twelve  parts  of  it  add  forty 
parts  of  white  lead,  thirty-six  of  feld- 
spar, eight  of  flints,  six  of  flint  glass, 
then  grind  the  whole  together  into  a 
paste.  These  substances  make  a  glaze 
which  is  not  easily  acted  upon  by  vege- 
table acids,  and  is  very  hard.  The  oxide 
of  tin  and  borax  is  said  to  produce  a  good 
common  glaze,  not  dangerous  like  lead 
for  cooking  vessels.  In  glazing  earthen- 
ware the  smallest  possible  quantity  of 
lead  should  be  used,  but  a  glaze  can  be 
made  of  ground  glass  and  borax  to  an- 
swer any  purpose,  for  what  is  a  glaze  but 
a  glass  surface  ? 

POULTRY.  Different  kinds  of  birds 
reared  for  the  production  of  eggs,  feath- 
ers, and  for  the  use  of  theirbodies  as 
animal  food.  The  domestic  poultry  in 
common  use  in  Britain  are  the  common 
domestic  fowls,  or  cock  and  hen,  the 
turkey,  the  duck,  and  the  goose  ;  to 
which  may  be  added,  as  occasionally 
reared,  the  guinea  fowl  and  the  peacock. 
The  most  generally  useful  kind  of  poul- 
try is  the  common  domestic  fowl,  which, 
though  a  native  of  India,  accompanies 
man  through  all  climates,  but  which  is 
only  productive  of  abundance  of  eggs 
when  well  fed  and  warmly  lodged. 
Hence,  all  poultry-houses,  when  not  built 
adjoining  an  apartment  in  which  fire  is 
kept,  or  over  a  stable  or  cow-house,  where 
they  might  benefit  by  the  heat  generated 
by  the  larger  animals,  ought  to  be  fur- 
nished with  fiues,  or  some  other  means 
of  generating  heat  artificially  during  win- 
ter and  spring.  Without  some  mode  of 
effecting  this,  poultry  will  seldom  pro- 
duce abundance  of  eggs  in  cold  weather, 


particularly  in  the  colder  parts  of  Brit- 
ain. Hence,  in  Scotland,  the  common 
hen  roosts  in  the  same  room  that  the 
cottager  lives  in  ;  and  the  poultry-house 
of  the  small  farmer  is  a  loft  either  over 
his  kitchen,  or  over  his  cow-house.  In 
the  management  of  poultry  it  is  not 
sufficient  to  supply  abundance  of  food 
and  warmth,  but  it  is  equally  necessary 
that  they  have  ample  space  for  exercise. 
This  space  should  always  contain  living 
plants  of  various  kinds,  and  some  grav- 
elly or  sandy  soil ;  because  worms,  snails, 
and  insects,  as  well  as  occasionally  grass 
and  herbage,  form  a  part  of  the  food  of 
poultry  ;  and  sand  or  gravel  is  swallowed 
by  them  for  the  purpose  of  promoting 
digestion.  Hence,  no  healthy  poultry 
can  ever  be  reared  in  towns,  however 
much  the  natural  food  may  be  imitated 
by  the  supply  of  animal  matters,  her- 
bage, and  sand  :  the  want  of  exercise  in 
poultry  so  circumstanced  will  soon  be- 
come evident  from  the  appearance  of  the 
fowls,  and  from  the  soil  shell  of  their 
eggs,  in  consequence  of  the  animal  func- 
tions not  being  efficiently  performed. 

In  the  management  of  ttiese  animals  it 
must  be  remembered,  cold  exercises  a 
constant  and  determinate  action  on  the 
lungs.  The  effect  of  this  action  is  the 
more  rapid  and  more  severe  the  younger 
the  animal  i3.  When  cold  does  not  cause 
acute,  and  speedily  fatal  inflammation 
of  the  lungs,  it  produces  a  chronic  in- 
flammation, which  is  pulmonary  con- 
sumption. Heat  always  prevents  "the  at- 
tack, and,  when  it  has  taken  place,  sus- 
pends its  progress,  and  even  sometimes 
arrests  it  entirely,  and  effects  a  complete 
cure.  Pulmonary  consumption  is  never, 
in  any  stage,  contagious  ;  and  fowls  af- 
fected with  that  disease,  are  not  only  all 
day  long  with  the  healthy  fowls,  but  at 
night  roosted  in  the  same  places,  without 
communicating  their  disease  to  them. 
Lastly,  the  action  of  too-long  confined 
air  exposes  these  animals  to  abscesses  of 
the  cornea,  and  inflammation  of  the  ball 
of  the  eye  ;  and  these  abscesses  and  in- 
flammations are  also  caused  by  cold,  es- 
pecially with  moisture. 

Breeding  Poultry. — The  houses  for  this 
purpose  may  be  built  either  of  brick  or 
stone,  one  story  high,  with  wooden  roofs, 
and  must  be  heated  by  cast-iron  steam- 
pipes.  Their  ceilings  and  walls  must  be 
finished  with  Roman  cement.  Each 
house  is  to  be  divided  iuto  four  compart- 
ments .: — the  first  for  hatching  and  rear- 
ing chickens  ;  the  second  for  breeding 
turkeys  ;  the  third  for  ducks  ;  and  the 


pou] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


48? 


fourth  for  geese.  A  furnace  is  built  at 
one  end,  with  a  steam  boiler  to  hold  50 
gallons  of  water,  which  will  heat  a  house 
80  feet  in  length.  The  first  two  compart- 
ments must  have  the  steam-pipes  pass  ! 
around  both  rooms  at  the  bottom  of  the 
walls,  for  hatching  chicken  and  turkey 
egirs,  and  they  must  pass  once  around  the 
other  two  rooms,  ducks  and  geese  requir- 
ing less  heat.  The  boiler  must  be  also 
so°constructed  as  to  steam  potatoes,  pars- 
nips, carrots,  and  herbs  ;  which,  when 
cooked  and  mixed  with  milk,  barley, 
oats,  or  peas,  meal,  or  flour,  produce  the 
finest  chickens,  and  other  poultry. 

To  make  the  hens  lay  all  through  the 
winter,  mix  powdered  oyster-shells  and 
slate,  or  decomposed  schistus  with  their 
food.  The  lime  in  the  oyster  shells  is 
necessary  to  form  the  shells  of  the  eggs, 
and  the  slate  improves  their  quality  and 
flavor. 

The  following  statistics  on  poultry  and 
eggs  drawn  from  the  Patent  Office  Re- 
ports for  1847  and  1848  have  some  in- 
terest. It  is  stated  that  a  bushel  of  corn 
will  last  twice  as  long  for  hens  as  a  bushel 
of  buckwheat,  but  the  latter  will  make 
hens  lay  eggs  more  than  any  other  grain, 
and  the  profit  overbalance  the  cost.  The 
number  of  eggs  sent  to  market  and  con- 
sumed is  very  great.  In  the  year  1846 
it  is  said  that  3,000,000  were  packed  and 
sent  from  Cincinnati  in  the  spring.  A 
single  canal  boat  is  noticed  in  a  Koch  ester 
paper  as  on  her  way  to  Albany  with  239 
barrels  of  eggs,  each  barrel  containing  90 
dozen,  which  would  thus  give  258,120 
dozen  eggs.  In  France  it  is  stated  that 
7,250,000,000  eggs  are  annually  used,  of 
which  Paris  consumes  about  120,000,000. 
The  importation  of  eggs  from  France  by 
England  amounted  in  1838  in  value  to 
nearly  $1,000,000,  and  the  annual  average 
amount  is  estimated  at  100,000,000  of 
eggs.  The  amount  of  money  invested  in 
poultry  in  Ensrland  is  supposed  to  be  not 
short  of  £8,000,000. 

In  Bixio's  Journal  d' Agriculture  Pra- 
tique et  Jardinage  for  April,  1848,  we 
find  a  statement  of  the  poultry  and  eggs 
of  France  alluding  to  actual  statistics,  he 
says  :  We  have  found  190,000  fowls  for 
85,685  inhabitants  ;  and  these  190,000 
fowls  give  annually  a  product  of  14,400,000 
eggs,  or  166  eggs  to  a  person  a  year.  Ex- 
tending this  calculation  to  the  whole  of 
France,  he  says  :  We  find  that  the  pro- 
portion of  population  to  the  number  of 
fowls  is  that  of  1  to  440.  Now  the  popu- 
lation of  France,  according  to  the  last 
census,  was  34,230,178  inhabitants,  and 


thus  it  will  follow  that,  in  the  actual  state 
of  affairs,  France  feeds,  by  methods  evi- 
dently defective,  47,938,628  fowls,  which 
at  120  eggs  each  for  a  year,  will  give 
5,752,635,360  eggs,  which,' at  4  francs  per 
100,  is  equal  to  230,100,414  francs,  equal 
to  $46,021,082  80,  (above  forty-six  mil- 
lions of  dollars,  allowing  20  cents  to  the 
franc.)  Adding  the  excess  of  30  eggs 
per  fowl  as  the  result  of  artificial  heat, 
there  would  be  150  eggs  per  fowl,  (12 
fowls,  placed  in  a  little  court  without  any 
other  heat  than  from  that  of  manure, 
laid  each  153  eggs,  on  an  average,  in 
1846  ;)  this  would  give  a  general  total 
of  3,396,931,400  eggs,  of  the  value 
of  287,631,768  francs  more,  (equal  to 
27,000,000  of  dollars.) 

We  have  heretofore  adverted  to  the  vast 
number  of  eggs  consumed  in  our  coun- 
try. We  find  a  variety  of  estimates  ; 
and  it  is  evident  that  in  many  sections  or 
the  country  both  the  amount  of  fowl  rais- 
ed and  eggs  consumed  is  very  much  larger 
than  in  others.  In  one  day,  from  Cincin- 
nati, Ohio,  it  is  stated  in  one  of  the  pub- 
lic journals,  there  were  shipped  500  bar- 
rels containing  47,000  dozen  of  eggs.  In 
some  of  the  States,  the  poultry  business 
appears  to  be  much  on  the  increase. 
In  the  state  of  New  York,  the  opening  of 
the  Erie  Eailroad  has  had  the  effect  of  in- 
creasing the  production  of  poultry  and 
eegs  to  an  incredible  extent— a  new  mar- 
ket being  found  in  the  middle  counties 
of  this  state,  to  supply  the  wants  of  half 
a  million  of  people  in  this  city. 

POWER-LOOM.     (£<><?  Weaving.) 

PNEUMATIC  TROUGH.  This  is  an 
apparatus  for  collecting  and  examining 
aeriform  bodies,  originally  invented  by 
Dr.  Priestley.  Wine  and  beer  glasses 
of  various  sizes  ;  apothecaries'  phials ; 
cleaned  oil  flasks,  with  glass  and  tin 
tubes  of  various  dimensions  ;  old  gun- 
barrels  ;  tobacco-pipes  ;  an  argand  and 
a  spirit-lamp,  with  a  common  fire  and 
bellows,  offer  inexhaustible  resources  to 
a  person  indued  with  the  faculty  of  con- 
trivance ;  especially  if  he  can  "seal  and 
bend  a  glass  tube  over  a  lamp. 

For  the  collection  of  gases,  sparingly 
soluble  in  water,  a  white  earthenware 
foot-bath,  or  a  small  washing-tub,  may 
be  employed.  In  this  a  shelf  should  be 
fixed.  A  glass,  or  metallic  tube,  proceed- 
ing from  the  vessel  containing  the  sub- 
stances from  which  the  aeriform  fluid  is 
emitted,  may  then  belaid  under  the  edge 
of  the  jar,  which,  for  this  purpose,  is 
permitted  to  project  a  little  over  the 
shelf ;  the  gas  will  then  rise  into  it  in 


488 


CYCLOPEDIA    OF    THE    USEFUL    A.RTS. 


bubbles,  and  gradually  displace  tbe  wa- 
ter. A  gas  may  also  be  readily  trans- 
ferred from  one  vessel  to  another,  by 
carefully  reclining  the  glass  which  con- 
tains it  under  the  edge  of  another  filled 
with  water,  and  projecting  over  the  shelf; 
and  they  may  likewise  be  removed  from 
the  bath,  and  transported  from  one  place 
to  another,  by  placing  them  in  shallow 
vessels  or  saucers,  and  surrounding  them 
with  about  an  inch  of  water. 

PRASE.  Green  quartz:  the  color  is 
due  to  actvnolite. 

PRECI PITATE.  A  result  of  chemical 
decomposition,  in  which  a  substance  is 
thrown  down  in  a  solid  and  finely-divided 
state  out  of  a  liquid. 

PREIINITE.  A  mineral  of  a  green  col- 
or, one  of  the  zeolites,  called  after  M.Prehn. 

PRESS.  1.  An  instrument  or  machine 
of  iron  or  wood  by  which  any  body  is 
squeezed,  crushed,  or  forced  into  a  more 
compact  form ;  as,  a  wine-press,  cider- 
press,  or  cheese-press.  Any  of  the  mechan- 
ical powers  may  be  used  for  this  purpose, 
and  also  the  hydrostatic  pressure  of  wa- 
ter. In  the  ordinary  presses,  the  screw 
is  employed  as  the  power.  Hydrostatic 
press,)  See  Bramah's  Press.)  2.  A  machine 
for  printing ;  a  printing  press.  Great 
improvements  have  been  lately  made  in 
the  construction  of  presses.  (See  Print- 
ing Press.) 

Press  for  compressing  Flour  orMeal  into 
Casks.  Every  barrel  ought  to  be  of  the 
size  to  contain  196  lbs.  of  meal  or  flour, 
when  compressed.  An  empty  barrel, 
with  a  false  one  of  the  same  size  (that  is, 
one  without  the  top  and  bottom),  placed 
above  it,  are  first  put  upon  the  scales. 
The  tare  is  made  ;  and  the  opposite  end 
of  the  balance  is  charged  with  a  weight 
of  196  lbs.  Meal  to  that  weight  is  then 
put  into  the  two  barrels  standing  in  this 
position,  as,  in  its  uncompressed  state, 
one  barrel  could  not  hold  this  quantity  of 
meal.  The  barrels  are  then  placed  under 
the  press,  where  a  rammer,  exactly  fitting 
the  barrel,  is  made  to  descend  upon  them  ; 
the  shaft  of  the  rammer  mounts  and  de- 
scends between  two  muffliner-boards, 
which  serve  to  guide  it.  It  is  furnished 
with  two  small  beams,  which  are  fixed  in 
a  sort  of  pivot,  and  which  form  the  ex- 
tremity of  a  large  lever.  When  this  lever 
is  lowered,  it  causes  the  rammer  to  de- 
scend upon  the  meal,  and  a  sufficient  de- 
gree of  pressure  is  thus  produced.  But, 
should  it  be  required  to  augment  the 
power  of  the  lever,  this  can  be  done  by 
applying  another  lever  to  assist  in  work- 
ing the  large  lever.    When  the  pressure 


is  finished  the  lever  is  raised,  and  the 
false  barrel,  which  is  now  empty,  is  re- 
moved. 

Copper-plate,  or  Boiling-Press.  The 
rolling-press,  which  is  employed  in  near- 
ly every  species  of  copper-plate  printing, 
is  divided  into  two  parts,  the  body  and 
the  carriage.  The  body  consists  of  two 
wooden  cheeks,  placed  perpendicularly 
on  a  stand  or  foot,  which  sustains  the 


whole  press.  From  the  foot,  likewise, 
rise  four  other  perpendicular  pieces,  join- 
ed by  cross  or  horizontal  ones,  which 
serve* to  sustain  a  smooth  even  plank  or 
table,  about  four  feet  and  a  half  long,  two 
feet  and  a  half  broad,  and  an  inch  "and  a 
half  thick.  Into  the  cheeks  go  two  wood- 
en cylinders  or  rollers,  about  six  inches 
in  diameter,  borne  up  at  each  end  by  the 
cheeks,  whose  ends,  which  are  lessened 
to  about  two  inches  diameter,  and  called 
trunnions,  turn  in  the  cheeks  about  two 
pieces  of  wood  in  form  of  half  moons, 
lined  with  polished  iron  to  facilitate  their 
motion.  Lastly,  to  one  of  the  trunnions 
of  the  upper  roller  is  fastened  a  cross, 
consisting  of  two  levers,  or  pieces  of  wood, 
traversing  each  other,  the  arms  of  which 
cross  serve  instead  of  the  bar  or  handle 
of  the  letter-press,  by  turning  the  upper 
roller,  and,  when  the  plank  is  between 
the  two  rollers,  giving  the  same  motion 
to  the  under  one,  by  drawing  the  plank 
forward  aud  backward.  The  ink  usually 
employed  is  a  composition  made  of  the 
stones  of  peaches  and  apricots,  the  bones 
of  sheep,  and  ivory,  all  well  burnt,  and 
called  Frankfort  Black,  mixed  with  nut- 
oil  that  has  been  well  boiled  ;  the  two  be- 
ing ground  together  on  a  marble  slab,  in 
the  same  manner  as  painters  grind  their 
colors. 

A  small  quantity  of  this  ink  is  taken 
on  a  rubber,  made  of  linen  rags,  strongly 


PRl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


489 


bound  about  each  other,  and  then  smear- 
ed over  the  whole  face  of  the  plate,  as  it 
lies  on  a  grate  over  a  charcoal  fire.  The 
plate  being  sufficiently  inked,  it  is  wiped 
over  with  a  dirty  rag,  then  with  the  palm 
of  the  left  hand,  then  with  that  of  the 
right ;  and  to  dry  the  hand,  and  forward 
the  wiping,  it  is  rubbed,  from  time  to 
time,  on  whiting.  In  wiping  the  plate 
perfectly  clean,  but  without  taking  the 
ink  out  of  the  engraving1,  consists  the 
skill  of  the  workman.  The  plate,  thus 
prepared,  is  laid  on  the  plank  of  the  press, 
and  over  the  plate  is  laid  the  paper,  well 
moistened  to  receive  the  impression ;  and 
over  the  paper  two  or  three  folds  of  flan- 
nel. The  arms  of  the  cross  are  then  pull- 
ed, and  the  plate,  with  its  furniture,  is 
passed  through  between  the  collars, 
which,  pinching  very  strongly,  press  the 
moistened  paper  into  the  strokes  of  the 
engraving,  and  it  absorbs  the  ink  from 
them. 

Dick's  Anti-Friction  Press.  Mr.  David 
Dick's  patented  press,  adapted  for  press- 
ing cotton,  punching,  straightening  rail- 
road iron,  embossing,  and  for  every  pur- 
pose of  pressing.  It  is  compact,  and  pre- 
sents a  most  important  arrangement  of 
mechanical  powers,  to  avoid  friction. 
The  great  principle  of  this  invention  is 
the  saving  and  centralizing  of  the  power, 
by  directing  the  power  which  is  applied 
through  a  line  of  contact  points.  In  all 
machinery  constructed  to  gain  power,  by 
losing  time,  to  use  common  terms,  the 
loss  by  friction  is  very  great,  such  as  blocks 
and  tackle,  and  other  machinery,  screw, 
&c,  where  the  power  is  transmitted  over 
a  great  extent  or  surface.  In  machinery 
for  lifting  or  pressing,  100  lbs.  passing 
through  two  feet  space,  will  lift  200  lbs. 
through  one  foot  of  space,  and  so  on  in 
the  same  ratio,  saving  the  friction,  which 
is  the  great  evil  of  all  complicated  machin- 
ery. This  great  drawback  (friction)  on 
power  is  removed,  to  a  great  extent,  in 
Mr.  Dick's  press. 

All  the  sectors  are  formed  alike,  but  re- 
versed in  position — the  upper  and  lower. 
There  are  two  partial  rotating  cams,  and 
two  cog-wheels  on  the  axle.  This  axle  is 
allowed  to  move  slightly  up  in  its  bear- 
ings. There  is  a  pinion  on  a  fixed  axis, 
which  is  operated  by  the  crank  handle. 
A  pinion  and  lever  are  employed,  as  re- 
quired, on  each  side.  There  are  sectors 
(four),  one  on  each  side  of  the  cams  ;  the 
lower  ones  are  in  a  reverse  position,  viz., 
resting  on  their  apex.  The  axle  of  the 
lower  cam  rests  on  curved  surfaces  of 
the  lower  sectors,  and  the  axle  of  the  up- 
21* 


per  cam  presses  on  the  curves  of  the  up- 
per sectors.  The  axle  of  the  upper  cam 
moves  upward  in  its  side  bearings,  and 
the  upper  sectors  are  pressed  upward, 
pushing  up  the  plate  or  frame,  which 
moves  upward  in  the  guide  slots.  The 
upper  sectors  move  in  one  direction, 
while  the  lower  ones  move  in  the  contrary 
direction,  bringing  their  curves  to  act 
most  effectually,  balancing  all  the  mo- 
tions, and  actiug  in  right  lines  through 
paints  of  contact,  produced  by  the  con- 
tact of  the  curved  surfaces  of  the  axles, 
cams,  and  sectors,  consequently  the 
amount  of  friction  is  very  small. 

POINTING  is  the  multiplication  of  co- 
pies by  movable  types.  It  superseded  the 
once  extensive  business  of  copying.  It  was 
a  mere  extension  of  the  art  of  coining  and 
seal  engraving,  on  which  letters  were  re- 
versed like  types,  but  the  impressions 
were  taken  in  wax  or  metal.  The  first 
printing  pages  were  blocks,  like  broad 
seals,  cut  in  wood,  and  stamped  on  paper, 
which  last  was  taught  by  card-making, 
cards  being  invented  about  half  a  century 
before,  and  the  impressions  made  with 
ink  and  blocks. 

The  history  of  its  origin  is  enveloped 
in  mystery ;  and  this  art,  which  commem- 
orates all  other  inventions,  which  hands 
down  to  posterity  every  important  event, 
which  immortalizes  the  actions   of  the 

§reat,  and  which,  above  all,  extends  and 
iffuses  the  Word  of  God  to  all  mankind ; 
this  very  art  has  left  its  own  origin  in  ob- 
scurity, and  has  given  employment  to 
the  studies  and  researches  of  the  most 
learned  men  in  Europe,  to  determine  to 
whom  the  honor  of  the  invention  is  due. 
According  to  Du  Halde  and  the  mis- 
sionaries, the  art  of  printing  from  en- 
g raved  blocks  of  wood  was  practised  in 
hina  nearly  fifty  years  before  the  Chris- 
tian era ;  and  from  the  early  commercial 
intercourse  of  the  Venetians  with  that 
country,  there  is  reason  to  believe  that 
the  knowledge  of  the  art,  and  of  its  appli- 
cation to  the  multiplying  of  books  was  de- 
rived from  thence ;  for  Venice  is  the  first 
place  in  Europe  of  which  we  have  any  ac- 
count in  which  it  is  practised,  as  appears 
by  the  decree  above  mentioned,  which  is 
the  most  ancient  document  in  existence 
respecting  printing ;  but  the  date  of  this 
application  of  the  art,  or  the  place  where 
it  was  first  practised,  it  is  impossible  to 
determine.  From  that  decree  and  the 
existence  of  the  print  of  St.  Christopher, 
it  would  seem  that  it  had  been  long  ap- 
plied to  the  production  of  playing-cards, 
and  of  religious  subjects,  and  when  it  was 


490 


CYCLOPEDIA    GF    THE    USEFUL    ARTS. 


[PRl 


extended  to  books,  they  were  printed  by 
the  Chinese  method,  still  in  use,  each 
page  being  engraved  on  a  block  of  wood : 
and  if  this  plan  was  followed,  as  most 
probably  it  was,  from  its  being  the  most 
correct — of  fastening  a  page  of  manu- 
script on  the  face  of  the  block  and  engrav- 
ing from  that,  instead  of  drawing  the 
characters  on  the  wood — it  would  at  once 
account  for  the  diversity  of  characters 
found  in  the  block  books,  which  varied 
with  the  different  handwritings  of  the 
scribes,  and  has  completely  puzzled  the 
learned,  who  endeavor  to  ascertain  the 
printer  by  comparing  the  characters  with 
some  other  work. 

About  the  year  1450,  the  great  and  ac- 
cumulating expense  of  engraving  blocks 
for  each  separate  work  of  the  increasing 
number  of  books  produced  by  means  of 
printing,  led  to  the  important  improve- 
ment of  the  art  of  casting  separate  metal 
types,  and  substituting  them  for  the 
wooden  blocks  previously  used.  This 
formed  a  new  epoch  in  the  art,  and  is  now 
termed,  erroneously,  the  origin  of  print- 
ing. After  a  lapse  of  many  years,  several 
cities  claimed  the  honor  of  this  invention, 
but  time  has  reduced  these  claims  to  two 
—Haarlem  and  Mentz. 

Many  of  the  manuscripts  of  the  14th 
and  15th  centuries  were  written  in  a  beau- 
tiful manner,  and  embellished  by  borders 
round  the  pages,  and  by  the  large  letters 
at  the  commencements  of  chapters  being 
drawn  and  colored  with  brilliant  colors, 
heightened  with  burnished  gold,  and  fin- 
ished with  taste,  delicacy,  and  great  abil- 
ity, so  as  to  produce  a  most  splendid 
effect.  These  were  called  illuminated 
manuscripts.  On  the  first  production  of 
books  by  the  process  of  printing,  these 
ornamental  letters  were  left  blank,  and 
both  these  letters  and  borders  were  fin- 
ished by  hand  in  the  usual  mancr,  which 
gave  to  the  book  a  perfect  resemblance  to 
a  manuscript,  of  which  it  became,  by 
these  means,  a  complete  facsimile.  This 
is  the  case  with  the  Mentz  Bible  by  Fust 
and  Gutenberg.  The  first  printers  soon 
began  to  print  these  large  ornamented 
letters,  the  letter  itself  being  in  some  in- 
stances red  and  the  ornamental  part  blue, 
in  others  the  letter  is  blue  and  the  orna- 
mental part  red ;  and  these  were  after- 
wards finished  by  hand,  as  is  apparent  in 
the  Psalter  of  1457,  printed  by  Fust  and 
Schoeffer,  who  also  showed  great  ingenu- 
ity and  skill  in  the  large  letter  B  in  the 
same  book,  which  is  printed  with  red 
ink,  and  the  ornamental  part,  consisting 
of  a  flourished  line,  as  if  it  had  been 


drawn  with  a  pen,  extending  from  the 
top  to  the  bottom  of  the  folio  page,  with 
blue  ink. 

The  means  in  use  among  the  Chinese 
for  producing  an  impression  of  letters 
appears  to  be  nearly  the  same  with  those 
invented  in  the  infancy  of  the  art.  Blocks 
of  hard  wood,  or  masses  of  metal  forming 
a  kind  of  stereotype,  are  printed  from, 
by  a  simple  and  expeditious  process,  and 
solely  by  manual  labor,  as  presses  for  the 

gurpose  are  entirely  unknown.  The 
anton  Gazette,  a  kind  of  court  journal 
of  appointments,  arrivals,  and  departures, 
is  one  of  the  few  publications  which  are 
printed  from  movable  types.  The  blocks 
which  are  mostly  used  for  engraving  these 
stereotypes  upon,  are  made  of  hard  and 
well-seasoned  wood,  divided  into  slabs, 
in  the  direction  of  the  grain.  The  sub- 
ject to  be  engraved  is  carefully  written  or 
drawn  on  thin  paper,  and  pasted  reversed 
upon  the  board;  the  wood  is  then  cut 
from  around  the  characters,  and  the  let- 
ters remain  in  low  relief.  Much  care  is 
used  in  adjusting  the  written  pattern,  as 
it  is  not  possible  to  rectify  a  mistake  on 
copper  or  other  metal.  The  cost  of  en- 
graving depends  entirely  on  the  size  and 
delicacy  of  the  letter,  the  price  increasing 
in  proportion  to  the  smallness  of  the 
type.  The  equipments  of  a  printer  are 
very  simple  and  cheap,  and  the  opera- 
tions less  complicated  than  almost  any 
other  mechanical  process.  The  board  or 
slab  of  wood  is  placed  on  a  table  before 
the  workman,  and  a  pile  of  dry  paper,  cut 
to  the  proper  size,  at  his  side,  when,  with 
a  rude  bamboo  brush,  a  coating  of  liquid 
Indian  ink  is  put  upon  it ;  a  sheet  of  pa- 
per is  then  placed  on  the  top,  and  the 
impression  completed  by  rubbing  it  over 
once  or  twice  with  a  kind  of  vegetable 
fibre  ;  the  sheet  is  then  lifted  off,  and  the 
process  repeated  with  the  next. 

In  the  actual  business  of  a  printing- 
office,  the  first  operation,  called  compos- 
ing, is  begun  by  the  compositor  laying 
the  letter,  called  types  (see  Types), 
into  as  many  cases  as  may  be  judged 
expedient  in  the  first  instance  (see 
Case),  laying  the  italic  in  cases  dis- 
tinct from  the  roman,  each  letter  or  sort 
in  the  box  appropriated  to  it:  having 
done  this  with  one  fount,  he  will  put  the 
cases  into  the  case  rack,  and  proceed  with 
another  fount,  till  the  whole  of  the  letter 
is  laid ;  he  will  put  the  superfluous  sorts 
either  into  a  font  case  or  into  coffins  ;  and 
he  will  then  be  ready  to  take  copy. 

The  compositor  having  taken  copy,  and 
received  directions  concerning  the  mea- 


PRl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


sure,  the  length  of  the  page,  any  peculiar- 
ity in  the  spelling  of  particular  words,  the 
use  of  capital  letters,  the  punctuation,  the 
words  that  are  to  be  in  italic  or  small 
capitals,  and  any  other  directions  that 
may  be  deemed  necessary,  proceeds  to 
make  his  measure,  and  cut  a  composing 
rule  ;  he  then  begins  to  compose,  letter 
by  letter,  till  he  has  formed  a  word ;  he 
separates  this  from  the  following  word  by  j 
a  space,  and  so  continues  till  he  has  com- 
posed a  line;  he  then  justifies  this  line 
by  increasing  the  space  between  the 
words,  or  lessening  it,  according  to  cir- 
cumstances, so  that  the  line  shall  be  to- 
lerably tight  in  the  composing  stick  ;  and 
thus  proceeds  till  he  has  completed  a  page  ; 
after  having  set  the  head  line  and  direc- 
tion line  with  the  signature,  he  ties  a  page- 
cord  round  it  to  preserve  it  from  falling 
asunder,  puts  it  on  a  page-paper,  andplaces 
it  on  the  bottom  of  his  frame ;  and  thus 
continues  till  he  has  composed  a  sheet. 

It  may  be  necessary  to  state  that  every 
line  is  of  the  same  length,  whether  the 
types  fill  it  out  or  not ;  the  last  line  of  a 
paragraph,  lines  of  poetry,  and  short  lines 
of  any  other  description,  are  filled  up 
with  quadrats  to  the  proper  length,  in  or- 
der that  they  may  be  secured  from  de- 
rangement by  being  wedged  up  in  the 
chase;  which  is  termed  locking-up. 

The  pages  are  then  taken  to  the  im- 
posing stone,  and  arranged  in  the  proper 
order ;  the  page-papers  removed  ;  a  chase 
is  then  placed  over  them,  furniture  put 
about  them,  and  the  pagecords  taken 
away;  proper  quoins  are  "then  selected, 
and  the  form  is  locked  up.  It  is  then 
taken  to  a  press,  and  one  impression  is 
printed ;  this  is  styled  the  first  proof, 
which  is  folded  and  taken  to  the  reader 
with  the  copy;  a  boy  reads  the  copy  to 
him,  while  he  examines  the  proof  and 
marks  the  errors  of  the  compositor,  and 
puts  a  queiy  to  any  doubtful  matter  for 
the  author's  consideration  ;  the  proof  is 
then  returned  to  the  compositor,  who 
corrects  the  errors  and  mistakes,  and  a 
second  impression  is  printed  with  more 
care  aud  generally  on  better  paper;  this 
is  styled  a  cle  m  proof;  it  is  examined  by 
the  first  proof  to  see  that  the  errors  of 
workmanship  are  corrected,  which  is 
termed  revising,  and  then  sent  out  with 
the  copy  to  the  author ;  he  makes  what 
alterations  and  corrections  he  may  think 
necessary;  these  are  corrected  by  the 
compositor :  another  impression  is 
printed,  revised,  and  read  finally,  and 
with  care,  for  press ;  the  margin  is  then 
adjusted  ;  and  the  corrections  being  care- 


fully made,  it  is  taken  to  the  press  to  be 
printed  off. 

In  the  mean  time,  after  the  author  has 
returned  the  sheet  for  press,  the  ware- 
houseman delivers  out  the  proper  quan- 
tity of  paper,  which  the  pressman  wets, 
by  drawing  the  paper,  to  the  extent  of 
three,  four,  five,  or  six  dips  for  each 
quire,  through  clean  water,  according  as 
the  paper  may  be  hard  sized  or  porous, 
and  also  as  the  form  may  be  solid  or  open  ; 
the  paper  as  it  is  wetted  is  laid  upon  a 
board,  opened  out,  and  another  board  is 
laid  upon  it  with  weights  ;  on  the  follow- 
ing day  it  is  turned,  which  causes  fresh 
surfaces  to  come  into  contact  with  each 
other,  and  diffuses  the  moisture  equally 
throughout  every  part  of  the  heap;  it 
will  be  in  good  condition  to  print  on  the 
next  day.  This  wetting  the  paper  causes 
it  to  receive  the  impression  of  the  ink  in 
a  much  more  perfect  manner  than  it 
could  possibly  be  made  to  do  if  dry. 

The  pressman  having  received  the 
forms,  lays  the  inner  form  on  the  press, 
and  prints  one  copy,  which  is  called  a 
revise ;  this  he  takes  to  the  person  ap- 
pointed to  revise  it,  and  while  that  is  do- 
ing, proceeds  to  secure  the  form  on  the 
table  of  the  press  by  means  of  quoins ;  to 
place  his  tympan  sheet ;  to  fix  the  points 
which  make  small  holes  in  the  paper  that 
enable  him  to  cause  the  pages  to  fall  pre- 
cisely on  the  back  of  each  other  when  the 
second  side  of  the  paper  is  printed,  and 
to  produce  an  even  and  uniform  impres- 
sion in  all  the  pages ;  he  then  cuts  his 
friskct,  which  preserves  the  margin  of 
the  paper  clean,  and,  when  the  revise  is 
corrected,  proceeds  to  ink  the  surface  of 
the  types  by  means  of  balls  or  rollers. 
When  the  whole  impression  of  one  side 
of  the  paper  is  printed,  he  lifts  the  form 
oft*  the  press,  washes  the  ink  off  the  face 
of  the  type  with  ley,  and  rinses  it  with 
water,  tie  then  proceeds  in  a  similar 
manner  with  the  outer  form,  which  com- 
pletes the  sheet ;  and  thus  sheet  after  sheet. 

If  it  be  intended  to  have  large  paper 
copies  of  a  work,  the  alteration  of  margin 
is  made  when  the  number  of  small  paper 
copies  is  printed  off  from  each  form. 

When  the  sheet  is  printed,  the  com- 
positor lays  it  up,  distributes  the  letter, 
and  proceeds,  sheet  after  sheet,  till  the 
body  of  the  work  is  finished  ;  then  the 
title,  dedication,  preface,  introduction, 
contents,  and  any  other  prefatory  matter 
is  proceeded  with,  these  being  always 
printed  the  last. 

The  warehouseman  then  takes  the 
printed  sheets  away,  and  hangs  them  up 


492 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PRI 


on  poles  to  dry,  varying  the  number  of 
sheets  hung  up  together  from  five  or  six 
to  ten  or  eleven,  according  to  the  state  of 
the  weather,  the  heat  of  the  room,  or  the 
pressure  of  business  ;  when  these  sheets 
are  dry  they  are  taken  down  from  the 
poles,  carefully  knocked  up,  and  put 
away  in  the  warehouse  in  piles;  when 
the  book  is  nearly  finished,  from  ten  to 
fourteen  consecutive  sheets  are  laid  upon 
the  gathering  table  in  order,  and  collect 
ed  sheet  by  sheet  by  boys,  who  deposit 
each  gathering  in  a  heap  at  the  end  of 
the  table,  which  is  generally  what  is  styl- 
ed a  horse-shoe  table,  so  that  when  a  boy 
has  deposited  his  gathering  he  has  only 
to  turn  himself  and  begin  again.  These 
gatherings  are  then  carefully  collated,  to 
ascertain  that  the  different  sheets  are  cor- 
rect and  in  order,  and  folded  up  the  mid- 
dle. When  the  work  is  finished  the  gath- 
erings are  put  together,  each  of  which 
forms  a  copy  of  the  work,  and  pressed  ; 
the  work  is  now  completed,  and  awaits 
the  order  of  the  bookseller,  &c,  to  deliver 
the  copies  either  to  himself,  the  book- 
binder, or  to  others,  according  to  circum- 
stances. 

The  foregoing  is  the  general  descrip- 
tion of  the  manner  in  which  printing  is 
conducted.  Each  style  of  work  has  its 
own  peculiarities,  and  each  office  has  de- 
tails appropriate  to  itself.  Philadelphia, 
Boston,  and  New-York,  are  the  cities 
where  the  great  bulk  of  book  printing  of 
this  country  is  performed.  Some  of  the 
printing  offices  of  these  cities  are  conduct- 
ed on  a  most  extensive  scale.  In  that  in 
which  this  Cyclopedia  is  stereotyped  and 
printed  (Mr.  J.  F.  Trow's),  there  are 
steadily  employed,  in  the  various  depart- 
ments of  proof-reading,  composing,  and 
press-work,  about  140  persons.  In  the 
composing  department,  where  every  de- 
scription of  book  and  job  printing  is  ex- 
ecuted— including  works  in  the  Oriental 
and  Classical  languages — the  average 
amount  of  daily  labor  performed  is 
equivalent  to  a  duodecimo  volume  of  350 
pages.  In  the  press-rooms,  there  are  13 
improved  Adams'  presses,  one  cylinder, 
and  three  hand-presses,  throwing  off 
daily  about  68,750  impressions— equal  to 
4,590  duodecimo  volumes  of  350  pages. 
Some  of  the  finest  specimens  of  American 
typography  have  issued  from  this  ex- 
tensive establishment — particularly  in  the 
Oriental  department,  in  which  branch  we 
believe  Mr.  Trow  has  no  competitor  in 
this  country. 

In  this  country,  females  are  employed 
in  some  cities  as  compositors. 


The  number  of  people  engaged  in 
these  employments  is  perhaps  about  the 
same  in  the  United  States,  as  in  Great 
Britain  and  in  France.  Germany  employs 
twice  as  many  ss  either  of  those  countries ; 
the  rest  of  Europe,  collectively,  as  many 
as  France.  In  all,  at  least  150,000  fami- 
lies subsist  in  the  civilized  world,  by 
imparting  knowledge  or  creating  the  faci- 
lities, besides  the  clergy  and  the  instruc- 
tors in  schools,  perhaps  twice  as  many 
more.     (See  Printing-Press.) 

PRINTING  INK  is  made  of  oil-var- 
nish and  fine  lampblack.  The  varnish 
is  made  by  heating  pure  linseed  oil  in  a 
copper  till  it  will  fight  with  a  piece  of 
lighted  paper.  It  is  then  made  to  burn  away 
to  three  quarters,  to  two  thirds  and  one 
half  for  varnishes,  of  various  consistence. 
The  lampblack  is  the  soot  of  turpentine 
lamps,  burnt  in  a  close  chamber,  and  the 
soot  collected  on  flannels  which  line  the 
room,  and  from  to  time  are  beat  out.  In 
a  large  way  the  oil  is  not  burnt,  but  evap- 
orated, at  nearly  a  boiling  heat,  to  a  thick 
consistence  ;  lampblack  is  often  made 
by  burning  pitch,  resin,  &c,  and  collect- 
ing the  soot  in  a  horizontal  chimney, 
which  passes  into  a  chamber  hung  with 
coarse  cloths  or  flannels.  The  ink  is 
made  by  gradually  triturating  the  black 
with  the  varnish  on  a  stone  with  a  muller, 
but  in  the  large  way  this  is  done  by  a 
horse-power  with  a  wheel,  in  the  manner 
of  color-grinding.  Balsam  copaiba,  soap, 
resin,  and  indigo  are  used  by  some  as  in- 
gredients in  the  ink. 

After  Ihe  smoke  begins  to  rise  from  the 
boiling  oil,  a  bit  of  burning  paper  stuck 
in  the  cleft  end  of  a  long  stick  should  be 
applied  to  the  surface,  to  set  it  on  fire,  as 
soon  as  the  vapor  will  burn;  and  the 
flame  should  be  allowed  to  continue  (the 
pot  being  meanwhile  removed  from  oyer 
the  fire,  or  the  fire  taken  from  under  fhe 
pot),  till  a  sample  of  the  varnish,  cooled 
upon  a  pallet-knife,  draws  out  into  strings 
of  about  half  an  inch  long  between  the 
fingers.  To  six  quarts  of  linseed  oil  thus 
treated,  six  pounds  of  resin  should  be 
gradually  added,  as  soon  as  the  froth  of 
the  ebullition  has  subsided.  Whenever 
the  resin  is  dissolved,  one  pound  and 
threo  quarters  of  dry  brown  soap,  of  the 
best  quality,  cut  into  slices,  is  to  be  in- 
troduced cautiously,  for  its  water  of  com- 
bination causes  a  violent  intumescence. 
Both  the  resin  and  soap  should  be  well 
stirred  with  the  spatula.  The  pot  is  to  be 
now  set  upon  the  fire,  in  order  to  complete 
the  combination  of  all  the  constituents. 

Put  next  of  well  ground  indigo  and 


«] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


493 


Prussian  blue,  each  2i  ounces,  into  an 
earthen  pan,  sufficiently  large  to  hold  all 
the  ink,  along  with  4  pounds  of  the  best 
mineral  lampblack,  and  then  3i  pounds 
of  good  vegetable  lampblack  ;  then  add 
tne  warm  varnish  by  slow  degrees,  care- 
fully stirring,  to  produco  a  perfect  incor- 
poration of  all  the  ingredients.  This 
mixture  is  next  to  be  subjected  to  a  mill, 
or  slab  and  muller,  till  it  be  levigated  in- 
to a  smooth  uniform  paste. 

One  pound  of  a  superfine  printing  ink 
may  be  made  by  the  following  recipe 
of  Mr.  Savage : — Balsam  copaiba,  9  oz. ; 
lampblack,  3  oz. ;  indigo  and  Prussian 
blue,  together,  p.  aeq.  1|  oz. ;  Indian  red, 
J  oz. ;  turpentine  (yellow)  soap,  dry,  3  oz. 
This  mixture  is  to  be  ground  upon  a  slab, 
with  a  muller,  to  an  impalpable  smooth- 
ness. The  pigments  used  for  colored 
printing  inks  are,  carmine,  lakes,  vermil- 
ion, red  lead,  Indian  red,  Venetian  red, 
chrome  yellow,  chrome  red  or  orange, 
burnt  terra  di  Sienna,  gall-stone,  Koman 
ochre,  yellow  ochre,  verdigris,  blues  and 
yellows  mixed  for  greens,  indigo,  Prus- 
sian blue,  Antwerp  blue,  lustre,  umber, 
sepia,  browns  mixed  with  Venetian  red, 
&c. 

PRINTING-PKESS  (Type)  is  the  very 
important  implement  used  for  transferring 
the  impressions  of  inked  types  to  paper. 
The  first  printing  was  effected  by  a  flat 
board  with  blows  of  a  mallet.  But  the 
number  of  impressions  rendered  it  ne- 
cessary to  convert  the  board  into  a  solid 
platten,  and  carry  this  upon  the  paper, 
by  means  of  a  screw,  and  a  lever  to  turn 
it.  The  types  were  inked  with  large 
balls,  made  of  sheep's  pelt,  and  the  soft 
covering  placed  over  the  paper,  to  pro- 
tect the  types,  and  bring  the  paper  into 
contact  with  the  entire  surface  of  each 
type  ;  but,  in  time,  this  has  been  changed 
into  the  tympan-frame  of  parchment  and 
interposed  flannel.  Such,  with  some 
changes  and  varieties  in  the  parts,  is  the 
ordinary  printing-press,  which  takes  off 
from  250  to  300  impressions  per  hour. 

Very  little  improvement  in  the  construc- 
tion of  this  instrument  took  place  from 
the  first  introduction  of  the  art  into 
Europe  till  the  late  Earl  Stanhope  applied 
the  powers  of  his  mind  to  the  subject, 
and  introduced  a  new  press  of  a  decidedly 
superior  construction.  The  old  press  was 
made  of  wood,  with  an  iron  screw  that 
had  a  bar  fitted  in  it ;  to  the  lower  end 
of  this  screw  was  attached,  horizontally, 
a  flat  piece  of  wood,  called  the  platen, 
which  was  brought  down  by  means  of  the 
screw,  and  pressed  the  paper  upon  the 


face  of  the  types  ;  and  thus  the  impres- 
sion was  obtained  This  press  has,  how- 
ever, entirely  given  place  to  presses  made 
of  iron.  Lord  Stanhope's  press  is  con- 
structed of  iron  with  a  screw  ;  but  the  bar 
is  fixed  to  an  upright  spindle,  to  which  a 
lever  is  attached  connected  with  a  second 
lever  fixed  to  the  top  of  the  screw  by  a 
connecting  bar.  These  two  levers  are  plac- 
ed at  different  angles  to  each  other  ;  and 
when  the  platen  is  brought  down  to  the 
face  of  the  types,  and  power  is  wanted, 
the  two  levers  take  such  a  position  with 
each  other  as  to  act  with  the  greatest  ad- 
vantage, and  thus  an  almost  incredible 
accession  of  power  is  gained,  which  ena- 
bles the  pressman  to  print  larger  sheets  of 
paper  in  a  superior  manner,  with  less 
labor,  and  with  greater  ease  to  himself. 
It  does  not  act  by  a  continuous,  but  by  a 
reciprocating  motion,  and  can  only  print 
250  impressions  per  hour.  This  press 
for  a  long  time  maintained  its  superiority- 
over  all  others. 


This  great  improvement  in  the  printing 
press  that  Lord  Stanhope  had  accom- 
plished, excited  other  ingenious  men  to 
exert  their  abilities  in  attempts  at  further 
improvements ;  among  whom  was  a  Mr. 
George  Clymer,an  American,who  brought 
forward  an  iron  press,  called  the  Colum- 
bian press,  in  which  he  discarded  the 
screw,  and  obtained  his  power  entirely  by 
levers.  This  press  has  great  power,  and 
consequently  great  strength,  and  is  made 
of  a  size  to  print  larger  sheets  of  papei 
than  any  other;  but  for  the  common  run 
of  printing  it  does  not  work  so  easy  as 
the  Stanhope  press. 
The  common  printing-press  in  which  the 


494 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PRI 


impression  is  given  by  a  compound  lever 
acting  on  an  inclined  plane,  is  found  suffi- 
ciently powerful  to  print  ancwspaper  form 
of  the  size  of  42X26  inches,  having  a  chase 
4  inches  larger  each  way.  It  requires  two 
persons  to  work  it,  one  of  whom  inks 
the  form  with  the  rollers  and  does  noth- 
ing else.  The  other  performs  the  princi- 
pal labor,  putting  on  and  taking  off  the 
sheet,  rolling  the  form  under  and  from 
under  the  platen,  and  giving  the  puli, 
which  is  necessarily  a  heavy  one.  The  ex- 
ertion required  to  throw  off  250  impres- 
sions in  an  hour  at  a  press  of  this  size  is 
very  great,  and  that  quantity  cannot  well 
be  exceeded. 

The  platen  power-press  of  the  best  con- 
struction has  self-inking  rollers  and  a  fly 
for  removing  the  printed  sheet  from  the 
type,  and  laying  it  on  the  heap.  It  is 
worked  by  two  persons,  one  of  whom,  a 
stout  man,  keeps  it  in  motion  by  turning 
a  crank  attached  to  a  fly-wheel,  and 
the  other  performs  the  light  duty  of 
putting  on  the  sheets.  The  bed  and 
platen  are  immense  masses  of  cast  iron, 
intended  by  their  strength  to  guard 
against  an  inclination  to  spring,  which  is 
very  apparent  in  the  hand-press,  and  par- 
tially corrected  by  making  the  bed  and 
?laten  slightly  concave  on  their  face, 
'he  platen  power-press  when  calculated 
to  print  a  form  of  42  by  26  inches,  will 
weigh  8,090  pounds,  and  when  worked 
by  one  man  at  the  crank  as  usual,  may 
give  400  impressions  in  an  hour,  or  if 
greater  speed  be  required,  with  the  aid  of 
a  steam  engine,  it  may  be  safely  worked 
at  600  impressions  per  hour.  It  is  a 
great  improvement  on  the  hand-press, 
whether  used  for  book  or  newspaper 
printing. 

Among  the  bed  and  platen  presses,  the 
most  valuable  and  most  extensively  used, 
are  those  manufactured  by  Mr.  J.  Adams, 
of  Boston.  Mr.  Adams  took  out  a  patent 
in  1830,  for  a  power-press,  and  in  1836 
another  for  an  improved  power-press. 
The  number  of  improvements  claimed  in 
the  specification  of  this  latter  patent  ex- 
ceeded twenty  in  nnmber,  some  of  which 
were  as  ingenious  as  they  were  novel. 
Mr.  Adams's  press  was  the  first  in  this 
country  to  which  a  fly  frame  was  attached. 
It  requires  but  one  person  (a  woman)  to 
tend  it  and  put  the  paper  on  the  register 
pins  ;  from  which  it  is  removed  by  the 
fingers  or  clips  which  carry  it  along  un- 
der the  platen,  where  it  remains  for  a 
second  to  receive  the  impression  of  the 
type.  The  latter,  placed  upon  a  movable 
bed,  travels  on  to  receive  the  ink  from  the 


self-acting  rollers,  returns,  and  when  im- 
mediately below  the  platen  is  carried 
upwards  by  the  action  of  a  crank  under- 
neath, and  is  pressed  against  the  surface 
of  the  paper  :  it  is  then  lowered,  passes 
against  a  side  table,  inked,  returns,  and 
renews  the  operation.  The  impressed 
sheet  is  carried  horizontally  on  tapes 
some  distance,  when  it  has  to  rise  an  inclin- 
ed plane  of  tape  to  come  within  the  reach 
of  the  fly  frame.  The  attraction  from  th  e 
horizontal  to  the  ascending  direction  is 
ingeniously  effected  by  means  of  a  bellows 
acted  upon  by  the  press  itself,  which 
blows  the  leaf  up  at  the  edge,  and  thus 
raises  it  over  the  first  difficulty,  that  of 
altering  its  direction.  It  is  removed 
from  the  tapes  by  the  fly  frame.  The 
whole  is  effected  with  great  rapidity  and 
little  noise.  It  throws  off  more  work 
than  any  English  press  of  a  similar  kind, 
the  larger  size  printing  readily  600  copies 
per  hour.  It  is  adapted  for  stereotype  and 
letter-press,  as  well  as  wood-cut  printing. 

The  cylinder  press  is  the  great  in- 
vention of  the  day  for  fast  printing  ;  and 
it  is  made  with  a  small  or  large  cylinder, 
according  as  it  is  to  be  used  tor  newspa- 
per or  book  work,  the  former  being  most 
favorable  to  rapid  printing,  and  the  lat- 
ter to  good  impressions.  It  has  self-ink- 
ing rollers,  pointing  apparatus,  and  a 
sheet-flyer.  When  it  is  to  be  worked  at 
its  greatest  speed,  it  must  be  impelled  by 
a  steam-engine,  and  then  2,500  impres- 
sions of  a  iorm  of  42  by  26  inches  may  be 
conveniently  taken  in  an  hour,  and  pos- 
sibly 3,000,  if  the  paper  can  be  fed  to  it 
by  one  person  so  fast.  When  it  is  driv- 
en by  a  man  with  a  crank  and  fly-wheel, 
800  impressions  of  the  same  form  may  be 
taken  in  an  hour,  and  the  work  of  feed- 
ing the  press  with  paper  at  this  rate  may 
be  done,  and  usually  is  done,  by  a  boy  or 
female.  All  cylinder  presses,  however, 
are  intended  to  be  used  for  rapid  work 
occasionally,  if  not  usually,  and  are  there- 
fore made  with  heavy  frames  and  strong 
working  parts,  to  endure  the  rapid  mo- 
tion and  the  sudden  reverses  which  at- 
tend the  printing  of  50  impressions  in  a 
minute  or  3,000  in  an  hour. 

From  the  preceding  statement  it 
thus  appears  that  when  two  persons 
work  either  of  the  above  presses,  the 
hand-press  gives  250  impressions,  the 
platen  power-press  400  impressions,  and 
the  cylinder  press  800  impressions,  per 
hour :  the  platen  power-press,  though 
much  heavier  than  the  hand-press,  giving 
double  its  number  of  impressions  by  a 
better  application  of  man-power ;  and  "the 


PBlJ 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


cylinder  press  giving  four  times  its  num  • 
ber  of  impressions  by  a  still  better  appli- 
cation of  the  same  power  on  a  lighter  ma- 
chine :  the  difference  in  the  movement 
of  the  respective  presses  being  pretty 
fairly  represented  by  saying,  that  the 
hand-press  is  in  actual  motion  one-third 
of  its  time,  the  platen  power-press  two- 
thirds,  and  the  cylinder  press  all  its  time, 
the  first  and  second  dwelling  upon  the 
impression  of  the  whole  form  with  great 
force,  while  the  latter  rolls  over  the  form 
lightly,  impressing  only  about  an  80th 
part  of  it  at  once. 

The  Printing  Machine,  is  the  adap- 
tation of  the  printing-press  to  the  moving 
power  of  steam.  The  types  are  laid  on  a 
stage,  imposed  in  the  usual  manner,  first 
one  side  of  the  sheet,  and  then,  a  little 
beyond  it,  the  other  side.  They  are  ink- 
ed by  passing  under  rollers  which  are 
supplied  with  ink  from  above.  The  paper 
is  then  placed  on  a  large  roller  by  a  boy, 
and  tho  roller  turning  passes  and  presses 
the  paper  over  the  type,  producing  a  per- 
fect impression  on  one  side.  The  sheet 
is  then  reversed  by  small  rollers  and  car- 
ried to  the  next  roller,  which  turns  it 
over  the  other  form  of  type  and  perfects 
*«,  when  a  boy  removes  it.  During  this 
time  the  first  boy  had  laid  another  sheet 
off  the  first  roller,  the  types  had  returned 
under  the  rollers,  and  received  fresh  ink 
from  the  ink  rollers,  the  first  roller  had 
turned,  the  two  small  rollers  had  laid  the 
reversed  sheet  on  the  second  roller,  which 
had  turned  and  perfected  it,  and  in  the 
9th  or  12th  of  a  second  of  time  the 
last  boy  receives  another  sheet.  The 
number  perfected  being  from  2,u00  to 
3,000  per  hour,  or  20  times  the  number 
by  ordinary  press-work,  performed  by 
two  hands  and  a  boy. 

The  printing-machine  was  invented  by 
Mr.  KSnig,  a  Saxon,  who  considered 
that  steam  might  be  employed  with 
advantage  to  expedite  the  process  of 
printing  ;  but  not  receiving  encourage- 
ment on  the  Continent  to  enable  him  to 
prosecute  his  plans,  he  came  to  England 
in  1804,  and,  after  explaining  his  views 
to  some  of  the  principal  printers  in  Lon- 
don, Mr.  Bensley,  Mr.  Woodfall,  and  Mr. 
Taylor,  embarked  in  the  undertaking,  but 
Mr.  Woodfall  soon  withdrew.  After  in- 
numerable experiments,  and  a  great  outlay 
of  capital,  the  result  was  not  satisfactory  ; 
but  the  experience  gained  by  prosecuting 
these  experiments  resulted  in  the  produc- 
tion of  a  machine  to  print  with  cylinders 
instead  of  a  flat  surface,  as  was  the  case 
with  the  printing  press,  which  was  limit- 


ed in  the  size  of  the  paper  by  the  size  of 
the  press  and  the  power  of  the  pressman. 
In  cylindrical  printing,  by  which  the 
pressure  is  communicated  in  lines,  the 
size  may  be  very  considerably  increased. 

The  first  machine  that  was  constructed 
was  capable  of  printing  1000  copies  per 
hour  ot  double  demy  paper  on  both  sides, 
while  a  hand-press  is  estimated  to  print 
250  copies  of  a  single  sheet  on  one  side 
only,  in  the  same  time. 

When  this  machine  was  completed, 
the  proprietors  of  the  Tomes  newspaper, 
ever  ready  to  adopt  any  improvement 
that  would  expedite  its  publication,  with- 
out regarding  expense,  agreed  with  the 
patentees  for  two  machines,  and  on  the 
28th  of  November,  1814,  the  Times  was 
published,  executed  by  cylindrical  print- 
ing, the  moving  power  being  steam ; 
these  were  the  only  machines  construct- 
ed under  the  first  patent — they  threw  off 
1,800  per  hour. 

In  1815,  Mr.  Cowper,  of  England,  ob- 
tained a  patent  for  curving'  stereotype 
plates,  for  the  purpose  of  fixing  them  on 
a  cylinder.  Several  machines  so  mounted, 
capable  of  printing  1000  sheets  per  hour 
upon  both  sides,  are  at  work  at  the  present 
day  ;  twelve  machines  on  this  principle 
having  been  made  for  Directors  of  the 
Bank  of  England  a  short  time  previous 
to  their  re-issuing  gold. 

Nicholson  sought  to  effect  the  revolu- 
tion of  the  form  of  types  by  giving  to  the 
shank  of  a  type  a  shape  like  the  stone  of 
an  arch ;  Donkin  and  Bacon  by  attach- 
ing types  to  the  sides  of  a  revolving 
Erism ;  and  Cowper,  more  successfully, 
y  curving  a  stereotype  plate.  In  these 
machines  Mr.  Cowper  places  two  paper 
cylinders  side  by  side,  and  against  each 
of  them  a  cylinder  for  holding'the  plates  ; 
each  of  these  four  cylinders  is  about  two 
feet  in  diameter.  Upon  the  surface  of  tho 
stereotype  plate  cylinder,  four  or  five  ink- 
ing rollers  of  about  three  inches  in  diame- 
ter are  placed ;  they  are  kept  in  their  po- 
sition by  a  frame  at  each  end  of  the  said 
cylinder,  and  the  axles  of  the  rollers  rest 
in  vertical  slots  of  the  frame,  whereby, 
having  perfect  freedom  of  motion,  they 
act  by  their  gravity  alone,  and  require  no 
adjustment. 

The  frame  which  supports  the  inking 
rollers,  called  the  waving-frame,  is  attach- 
ed by  hinges  to  the  general  framework  of 
the  machine ;  the  edge  of  the  stereotype- 
plate  cylinder  is  indented,  and.  ruba 
against  the  waving-frame,  causing  it  to 
vibrate  to  and  fro,  and  consequently  to 
carry  the  inking  rollers  with  it,  so  as  to 


496 


CYCLOPEDIA    OF    1HE    USEFUL    ARTS. 


[PRi 


give  them  an  unceasing  traverse  move- 
ment. These  rollers  distribute  the  ink 
over  three-fourths  of  the  surface  of  the 
cylinder,  the  other  quarter  being  occupied 
by  the  curved  stereotype  plates.  The  ink 
is  contained  in  a  trough,  which  stands 
parallel  to  the  said  cylinder,  and  is  formed 
by  a  metal  roller  revolving  against  the 
edge  of  a  plate  of  iron  ;  in  its  revolution 
it  gets  covered  with  a  thin  film  of  ink, 
which  is  conveyed  to  the  plate  cylinder 
by  a  distributing  roller  vibrating  between 
both.  The  ink  is  diffused  upon  the  plate 
cylinder  as  before  described  ;  the  plates 
in  passing  under  the  inking  rollers  become 
charged  with  the  colored  varnish  :  and  as 
the  cylinder  continues  to  revolve,  the 
plates  come  into  contact  with  a  sheet  of 
paper  on  the  first  paper  cylinder,  which 
is  then  carried  by  means  of  tapes  to  the 
second  paper  cylinder,  where  it  receives 
the  impression  upon  its  opposite  side 
from  the  plates  upon  the  second  cylin- 
der. 

Thus  the  printing  of  the  sheet  is  com- 
pleted. Though  the  above  machine  be 
applicable  only  to  stereotype  plates,  it 
has  been  of  general  importance,  because 
it  formed  the  foundation  of  the  future 
success  of  Messrs.  Cowper  and  Apple- 
gath's  printing  machinery,  by  showing 
them  the  best  method  of  serving  out, 
distributing,  and  applying  the  colored 
varnish  to  the  types. 

In  order  to  adopt  this  method  of  ink- 
ing to  a  flat  type-form  machine,  it  was 
merely  requisite  to  do  the  same  thing 
upon  an  extended  flat  surface  or  table, 
which  had  been  performed  upon  an  ex- 
tended cylindrical  surface.  Accordingly, 
Messrs.  "  Cowper  and  Applegath  con- 
structed a  machine  for  printing  both 
sides  of  the  sheets  from  type,  including 
the  inking  apparatus,  and  the  mode  of 
conveying  the  sheet  from  the  one  paper 
cylinder  to  the  other,  by  means  of  drums 
and  tapes.  _  It  is  highly  creditable  to  the 
scientific  judgment  of  these  patentees, 
that  in  new  modelling  the  printing  ma- 
chine they  dispensed  with  forty  wheels, 
which  existed  in  Mr.  Konig's  apparatus, 
when  Mr.  Bensley  requested  them  to  ap- 
ply their  improvements  to  it. 

In  England,  Treadwell's  power-press 
has  been,  until  lately,  very  much  em- 
ployed. In  this  invention  the  types 
are  inked  by  elastic  rollers,  and  the "dis- 
tribution of  the  ink  rendered  equal  by 
a  revolving  table,  which  keeps  in  contact 
with  the  rollers.  The  impressions  are 
made  by  a  flat  surface,  or  platen,  instead 
of  a  cylinder,  so  that  cleaner  and  better 


impressions  are  supposed  to  be  obtained 
from  it,  than  by  any  other  machine. 

Konig's  machine  continued  in  use  by 
the  Times  newspaper  (England)  till  1827, 
when  it  was  superseded  by  Applegath  <fc 
Cowper's  four-cylinder  machine,  produ- 
cing 5000  per  hour.  Some  of  them  are 
still  used  in  that  office.  They  consist  of 
a  table  moving  to  and  fro  under  four  iron 
cylinders,  about  nine  inches  diameter, 
covered  with  cloth,  and  round  which  the 
paper  is  carried.  The  form  is  fixed  at 
one  part  of  the  table,  and  the  ink  and 
paper  at  another.  Some  of  the  rollers 
were  laid  diagonally,  so  that  as  the  table 
moved,  the  rollers  had  a  motion  in  the 
direction  of  their  length ;  this  movement 
aided  the  rotatory  one  in  better  inking  ; 
the  ink  lay  in  in  a  trough  in  an  iron  roller 
or  dorter,  exactly  similar  to  that  used  in 
Calico  printing  (which  see).  Four  layers- 
on  fed  the  rollers,  which  by  tapes  carried 
the  sheets  to  the  takers-out  at  the  other 
end.  In  May,  1848,  the  last  improve- 
ment was  made  by  the  adoption  of  a 
new  machine,  which  threw  off  the  large 
quantity  of  10,000  copies  per  hour.  This 
machine  was  a  vertical  cylinder,  65  inches 
broad,  on  which  the  type  was  fixed,  sur- 
rounded by  eight  other  cylinders,  each 
about  13  inches  diameter,  and  covered 
with  cloth,  round  which  the  paper  was 
led  by  tapes,  each  paper  cylinder  having 
a  feeding  apparatus  and  two  boys  tend- 
ing. The  ink  rollers  were  also  vertical 
against  the  large  cylinder,  and  on  which 
they  distributed  the  ink.  This  last  was 
in  a  vertical  cylinder.  The  type  used  is 
the  ordinary  kind,  and  the  form  is  placed 
on  a  portion  of  the  large  cylinder.  The 
surface  of  the  type  formed  a  portion  of  a 
polygon,  and  the  regularity  of  the  im- 
pression was  obtained  by  pasting  slips  of 
paper  on  the  cylinders.  On  the  7th  May, 
1850,  the  Times  newspaper  and  Supple- 
ment contained  72  columns  or  17,500  lines 
made  up  of  more  than  a  million  pieces  of 
type ;  of'  this  copy,  the  hist  form  went  to 
press  at  4  45  A.M.,  7000  copies  were  pub- 
lished before  6  A.M.,  17,000  before  7  80  A. 
M.,  and  84,000  before  8  45  A.  M.,  or  in 
about  four  hours.  On  March  9th,  1850, 
an  exhibition  of  a  new  rotary  press  took 
place  in  Paris,  which  was  worked  by  cylin- 
drical motion,  and  by  a  stereotype  obtain- 
ed from  several  sheets  made  of  a  pulp  of 
paper,  which  gives  more  depth  than  is 
usually  obtained  from  plaster  of  Paris, 
and  the  printing  is  so  perfect2  that  even 
maps  are  produced  from  their  cylindri- 
cal stereotypes  with  the  minutest  accuracy. 
It  is  the  invention  of  Worms,  once  a  Par- 


FRl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


491 


risian  printer.  The  stereotype  cylinder 
was  got  up  in  15  minutes  and  the  print- 
ing on  both  sides  was  most  perfect.  It 
knocked  off  15,000  copies  by  the  hour; 
this  may  be  augmented  by  steam  power. 
The  rapidity  is  owing  to  the  printing  on 
endless  paper  not  wetted  on  rollers,  each 
copy  being  cut  up  with  great  precision. 

This  French  rotary  press  has  been  ex- 
celled by  the  mammoth  press,  the  largest 
ever  constructed.  It  was  designed  and 
built  by  Messrs.  Hoe  &  Co.,  New- York  : 
it  is  forty  feet  in  length  and  five  wide ;  it 
has  a  large  central  drum  which  revolves 
like  a  broad  wheel.  The  form  (or  there 
may  be  a  number  of  them)  is  placed  on 
the  periphery  of  the  central  drum,  but 
only  occupies  a  portion  of  it.  The  chase 
is  curved  and  forms  the  section  of  a  cir- 
cle, with  the  surface  of  the  type  forming 
the  outside  of  the  same.  The  type  are 
secured  in  the  curved  chase  in  a  pecu- 
liar manner.  The  column-rules  are 
straight  and  run  parallel  with  the  shaft 
of  the  large  drum;  the  head  and  dash- 
rules  are  curved.  The  column-rules  have 
bottom  flanges  ;  they  slide  in  the  grooves 
in  the  bed  of  the  chase,  and  are  secured 
by  brass  dove-tail  wedges.  The  cross 
section  of  a  column-rule  is  of  a  wedge 
shape,  being  thinner  at  the  bottom  than  at 
the  top,  to  wedge  in  the  type  at  the  wid- 
est part  of  a  circle  which  they  form  with 
the  large  drum.  This  is  an  essential  fea- 
ture in  securing  the  type,  and  its  appli- 
cation is  certainly  the  result  of  a  very 
happy  thought.  The  type  is  firmly 
screwed  up  in  the  chase  by  set  screws. 

The  surface  of  the  large  drum  of  the 
press  is  composed  of  smooth  metal 
plates,  and  performs  the  office  of  an  ink 
distributor  to  the  small  rollers  which  ink 
the  type.  Below  the  large  rotary  drum, 
there  is  a  trough  running  across  the 
frame,  into  which  the  ink  is  pumped 
from  a  reservoir  by  a  force  pump,  so  as 
to  keep  the  trough  always  full.  Above 
the  ink.  trough  there  revolves  a  large 
roller,  which  takes  up  the  ink  on 
its  surface,  conveys  it  to  another 
roller,  that  one  to  a  third,  and  it  to  the 
Bmooth  surface  of  the  revolving  drum, 
distributing  the  ink  on  it.  The  use  of 
the  three  rollers  to  convey  the  ink  from 
the  trough,  is  to  work  and  spread  it  on 
the  distributing  surface.  As  the  type  in 
the  chase  stands  higher  than  the  smooth 
surface  of  the  rotary  drum,  the  ink-roller 
below  would  cover  the  type  with  ink 
when  it  came  round  to  it,  were  it  not  for 
a  contrivance  of  Messrs.  Hoe  to  obviate 
this  difficulty.    The  large  ink-roller  below 


has  its  gudgeons  worked  on  springs, 
which  press  it  up  against  the  smooth 
surface  of  the  large  drum,  except  at  the 
exact  time  during  the  passage  of  the 
type :  then  a  cam  forces  down  the  ink- 
roller  below  the  surface  of  the  type,  until 
the  form  is  past  the  point  of  contact, 
when  it  rises  up  against  the  distribution 
surface  with  its  supply  of  ink. 

Around  the  fixed  trame  at  different  but 
exact  points  above  the  large  drum,  there 
are  eight  revolving  tympan  cylinders,  or 
rollers,  which  feed  in  the  sheets  to  the 
revolving  drum,  and  against  the  surface 
of  which  the  form,  as  it  revolves,  im- 
presses the  paper.  The  attendants  push 
in  the  sheets,  one  by  one,  to  the  tytn- 
pans,  in  each  of  which  is  an  open  section, 
with  fingers  worked  by  a  cam,  which  are 
open  when  they  come  round  to  receive  a 
sheet,  then  close  upon  it,  wrapping  the 
said  sheet  around  the  smooth  surface  of 
the  tympan  ;  at  this  very  period,  the  type 
on  the  large  drum  has  come  round,  and 
is  acting  on  the  paper.  When  the  type 
has  printed  the  sheet,  the  fingers  spoken 
of  open  like  the  human  hand  and  the 
printed  sheet  is  whipped  off  the  tympan 
and  carried  away  back  to  the  end  of  the 
press,  there  to  be  taken  off  and  folded 
neatly  down  by  a  vibratory  flyer,  four  of 
which  are  placed  one  above  another, 
(one  for  each  tympan,)  at  each  side  of 
the  press.  The  two  outside  edges  of 
each  sheet  of  paper  are  held  against  a 
smooth  narrow  strap  on  the  tympan  on 
each  side.  Above  each  tympan  cylinder 
it  will  be  observed  there  are  a  number 
of  small  pulleys,  with  straps  running 
around  them,  extending  the  whole  length 
of  each  tympan,  and  running  on  its  sur- 
face. The  straps  of  these  small  pulleys 
run  away  back  over  a  like  set  of  pulleys, 
above  the  flyers.  Whenever  the  type 
forms  its  impression  on  the  sheet,  the 
fingers  spoken  of  let  the  paper  free,  and 
then  these  small  straps  wnip  up  the 
sheet  and  carry  it  along,  as  on  a  flying 
railroad,  to  be  folded  by  the  flyer.  Aftei 
the  form  makes  its  impression  on  the 
paper  which  is  wrapped  around  the  tym- 
pan, it  comes  in  contact  with  the  two 
small  ink-rollers,  which  ink  the  surface 
of  the  type,  and  fit  it  to  print  the  sheet 
on  the  next  tympan,  and  so  on  continu- 
ally. These  small  inking  rollers  have 
their  journals  fitted  on  springs,  so  as  to 
allow  them  to  be  pushed  up  or  down  by 
the  type,  and  then  to  be  forced  against 
the  distributing  surface,  to  take  up  the 
ink  for  their  next  performance. 

In    this    one  press,   it  may  be  said, 


498 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PRI 


"  their  are  eight  combined,"  that  is,  in 
respect  to  its  effective  power.  One, 
two,  three,  or  more  tympan  cylinders 
can  be  detached,  and  the  rest  left  free 
to  work.  This  makes  it  very  conveni- 
ent, for  it  requires  but  a  moment's  labor 
to  set  the  press  so  as  to  work  with  any 
number  less  than  the  eight  attendants. 

Although  this  machine  is  so  large, 
strictly  speaking  it  is  exceedingly  simple 
in  its  operaiton,  and  it  works  with  a 
smoothness  and  regularity  that  commands 
admiration.  The  building  of  this  great 
press  for  the  New-York  Sun  was  com- 
menced in  1849,  and  it  was  completed  in 
1851. 

In  the  construction  of  this  press 
Messrs.  Hoe  &  Co.  state  that  there  are 
employed  no  less  than  six  thousand 
bolts  and  screws,  one  thousand  two 
hundred  wheels,  two  hundred  and  two 
wooden  rollers,  four  hundred  pulleys, 
four  hundred  tape  guides,  besides  an 
amazing  amount  of  cogged  wheel  con- 
nections, arms,  braces,  and  other  con- 
nections. There  are  also  required  to  give 
motion  to  various  parts  of  the  machine, 
no  less  than  five  hundred  yards  of  belting. 

It  can  print  20,000  copies  in  one  hour. 
It  has  been  in  successful  operation  print- 
ing the  New-York  Sun  for  the  past  six 
months,  and  it  operates  with  astonishing 
precision. 

The  manufactory  of  Messrs.  Hoe  &  Co., 
N.  Y.,  is  the  most  extensive  one  of  its 
kind  in  this  country.  In  it  are  made 
several  varieties  of  presses,  both  cylinder 
and  platen  ;  a  description  of  those  man- 
ufactured in  that  establishment  to  a  great 
extent  comprehends  the  notice  of  those 
presses  most  in  use.  Among  the  cylin- 
der presses  are, 

1.  The  Type  Revolving  Fast  Printing 
Machine,  the  mechanism  of  which  is  as 
follows : — 

A  horizontal  cylinder  of  about  four 
and  a  half  feet  in  diameter,  is  mounted 
on  a  shaft,  with  appropriate  bearings ; 
about  one-fourth  of  the  circumference 
of  this  cylinder  constitutes  the  bed  of 
the  press,  which  is  adapted  to  receive 
the  form  of  types — the  remainder  is  used 
as  a  cylindrical  distributing  table.  The 
diameter  of  the  cylinder  is  less  than  that 
of  the  form  of  types,  in  order  that  the 
distributing  portion  of  it  may  pass  the 
impression  cylinders  without  touching. 
The  ink  is  contained  in  a  fountain  placed 
beneath  the  large  cylinder,  from  which 
it  is  taken  by  a  ducter  roller  and  trans- 
ferred, by  a  vibrating  distributing  roller, 
to  the  cylindrical  distributing  table ;  the 


fountain  roller  receives  a  slow  and  con- 
tinuous rotary  motion,  to  carry  up  the 
ink  from  the  fountain. 

The  large   cylinder  being  put  in  mo- 
tion,  the  form  of  types   thereon  is,  in 
succession,  carried  to  four  or  more  cor- 
responding horizontal  impression  cylin- 
ders, arranged  at  proper  distances  around 
it,  to  give  the  impression  to  four  or  more 
sheets,   one  introduced  by  each  impres- 
sion cylinder.    The  fly  and  feed-boards 
of  two  of  the  impression  cylinders  are 
similar  to  those  on  the  well-known  dou- 
ble cylinder    press ;    on  the  other  two, 
the  sheet  is  ted  in   below  and  thrown 
out    above.      The     sheets     are    taken 
directly    from  the  feed-board,   by  iron 
fingers    attached    to     each    impression 
cylinder.    Between  each  two  of  the  im- 
pression cylinders  there  are  two  inking 
rollers,  which  vibrate  on  the  distributing 
surface  while  taking  a  supply  of  ink,  and 
at  the  proper  time  are  caused  to  rise, 
by  a  cam,  so  as  to  pass  over  the  form, 
when  they  again  fall  to  the  distributing 
surface.    Each  page  is  locked  up  upon  a 
detached  segment  of  the  large  cylinder, 
called   by    the  compositors   a    ""turtle," 
and  this  constitutes   the  bed  and  chase. 
The  column-rules  run   parallel  with  the 
shafts  of  the    cylinder,  and  are  conse- 
quently   straight ;    while  the  head,  ad- 
vertising,   and    dash-rules    are    in   the 
form  of  segments   of  a  circle.     A  cross 
section  of  the  column-rules  would  pre- 
sent the    form  of   a    wedge,   with    the 
small  end  pointing  to  the  centre  of  the 
cylinder,  so    as  to  bind  the  types   near 
the  top ;  for  the  types  being  parallel,  in- 
stead of  radiating  from  the  centre,  it  is 
obvious  that    if  the  column-rules  were 
also  parallel,  they  must  stand  apart    at 
the  top,  no  matter  how  tight  they  were 
pressed  together  at  the  base ;   but  with 
these  wedge-shaped  column  rules,  which 
arc  held  down  to  the  bed  or  "turtle"  by 
tongues,  projecting  at  intervals  along  their 
length,  and   sliding    in  rebated  grooves 
cut  crosswise  in  the  face  of  the  bed,  the 
space  in  the  grooves,  between  the  col- 
umn-rules,    being     filled    with    sliding 
blocks    of  metal,  accurately   fitted,  the 
outer  surface  level,  with  the  surface  of 
the  bed,  the  ends  next  the  column-rules 
being  cut  away  underneath  to  receive  a 
projection  on  the  sides  of  the  tongues, 
and  screws  at  the  end  and  side  of  each 
page  to  lock  them  together,  the  types 
are  as  secure  on  this  cylinder  as  they 
can  be  on  the  old  flat  bed. 

A  press  with  four   impression  cylin 
ders  is  capable  of  printing  10,000  im 


PRl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


499 


pressions  per  hour.  Four  persons  are 
required  to  feed  in  the  sheets,  which  are 
thrown  out  and  laid  in  heaps  by  self- 
acting  flyers,  as  in  our  ordinary 
cylinder  presses.  A  press  with  eight 
impression  cylinders  will  print  16,000 
or  more  impressions  per  hour. 

2.  The  Single  Smalt  Cylinder  Printing 
Machine.  In  this  press  the  form  is 
placed  on  a  flat  bed,  and  the  impres- 
sion taken  on  the  paper  by  a  cylinder 
while  the  form  is  passing  under  it.  The 
diameter  of  the  cylinder  is  small,  allow- 
ing of  compactness,  and  increases  the 
number  of  impressions  in  a  given  time. 
One  person  only  is  required  to  feed  it, 
and  it  gives  from  2,000  to  3,000  im- 
pressions per  hour.  The  printed  sheets 
are  thrown  out  by  a  fly  frame.  By 
the  addition  of  a  register  point  appara- 
tus it  is  rendered  fit  for  book  printing. 
It  may  be  driven  by  hand  or  steam. 

3.  T he  Double  Cylinder  Printing  Ma- 
chine, has  an  arrangement  similar  to 
the  foregoing,  with  the  addition  of  ano- 
ther impression  cylinder,  which  gives 
an  additional  impression  from  the  same 
form.  Two  attendants  supply  the  sheets, 
which  is  all  that  is  required  for  large  edi- 
tions, but  where  small  editions  are  work- 
ed off  two  boys  extra  are  required  to  take 
out.  A  view  of  this  press  is  given  in 
the  accompanying  page. 

4.  Patent  Single  Large  Cylinder  Ma- 
chine. In  this  the  cylinder  is  of  greater 
diameter  than  in  any  of  the  foregoing. 
It  has  a  perfect  register  and  sheet  flyer, 
and  adjustable  bearers  of  iron,  so  that 
stereotype  may  be  worked  on  it.  One 
boy  is  required  to  feed,  and  it  gives 
from  one  to  two  thousand  impressions 
per  hour.  Man  or  steam  power  may  be 
used.  India-rubber  impression  cloths 
are  used  with  these  presses.  An  illus- 
tration of  this  oress  is  here  subjoined. 

5.  The  Little  Jobber.  This  press  com- 
bines speed  with  durability.  It  is  capa- 
ble of  throwing  off  2.500  impressions 
per  hour.  It  may  be  driven  by  the  foot 
and  treadle.  The  manner  of  running  the 
bed  is  original,  being  accomplished  by  a 
crank  and  lever,  which  gives  it  a  slow 
and  uniform  motion,  while  the  impres- 
sion is  being  taken,  and  a  quick  retro- 
grade motion.  The  sheet-flyer  is  so  ar- 
ranged that  no  tapes  pass  round  the  im- 
pression cylinder,  no  matter  what  the 
size  of  the  form  may  be  that  is  worked, 
and  thus  no  tapes  or  fingers  have  to  be 
shifted.  It  has  iron  feed  and  fly  boards, 
and  adjustable  fountain,  knife,  and 
boarers. 


The  Patent  Washington  Hand  Press, 
and  the  Patent  Smith  Press,  are  conveni- 
ent forms  of  the  bed  and  platen  variety. 
Messrs.  Hoe  have  attached  to  these 
presses  self-inking  rollers,  which  may  be 
thus  described.  The  large  distributing 
cylinder  vibrates  :  there  are  two  rollers 
to  ink  the  forms,  moving  in  a  carriage 
with  four  wheels.  The  wheels  on  one 
i  end  are  plain,  those  on  the  other  have  a 

Projecting  flange  in  the  middle  of  the  rim. 
'wo  wrought  iron  rails  are  on  the  bed 
outside  of  the  chase,  one  of  them  hav- 
ing a  groove  cut  in  its  top  to  receive  the 
projecting  flanges  on  one  pair  of  the 
wheels,  the  other  level  on  the  surface. 
Projecting  from  tUe  distributor  frame 
are  two  short  rails,  on  which  the  wheels 
rest  while  the  rollers  receive  ink  from 
the  distributing  cylinder.  The  machine 
is  set  up  behind  the  press  so  that  the 
short  rails  on  it  shall  agree  exactly  with 
the  rails  on  the  bed  of  "the  press,  when 
it  is  run  out,  both  in  height  and  width. 
The  brasses  in  which  the  inking  rollers 
run,  have  regulated  adjusting  screws, 
so  that  they  may  bear  more  or  less  on 
the  type  as  circumstances  may  require. 

PROMETHEANS.  A  term  applied  to 
small  glass  tubes  containing  concentrated 
sulphuric  acid,  and  surrounded  with  an 
inflammable  mixture,  which  they  ignite 
on  being  pressed,  and  thereby  give  in- 
stantaneous light. 

PROOF.  In  engraving,  an  impression 
taken  from  an  engraving  to  prove  the 
state  of  it  during  the  progress  of  execu- 
ting it ;  also  one  taken  before  the  inser- 
tion of  the  letters  are  engraved  on  the 
plate. 

Proof.  In  printing,  an  impression  on 
which  the  errors  and  mistakes  are  mark- 
ed  for  the  purpose  of  being  corrected. 
Proofs  are — first  proof,  which  is  the  im- 
pression taken  with  all  the  errors  of 
workmanship.  After  it  is  read  by  the 
copy,  and  the  errors  corrected,  which  if 
not'  many,  and  carefully  done,  another 
impression  is  printed  with  more  care,  to 
send  to  the  author;  this  is  termed  a 
clean  proof.  On  it  he  makes  his  correc- 
tions and  alterations:  when  those  are 
altered  in  the  types,  another  proof  is 
printed,  and  read  over  carefully,  previ- 
ously to  the  whole  number  being  printed 
off;  this  is  called  the  press  proof. 

PROOF  SPIEIT.  A  mixture  of  equal 
weights  of  absolute  alcohol  and  water ; 
the  specific  gravity  of  such  a  mixture  is 
0-917  ;  but  the  density  of  the  proof  spirit 
of  commerce  is  0'930. 

PROPAGATION    OF    PLANTS 


500 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[PRI 


Plants  are  propagated  by  seed,  by  run- 
ners, suckers,  offsets,  dividing  the  tu- 
bers, layers,  cuttings,  grafting,  budding, 
inarching,  &c.  Seeds  are  gathered  when 
mature,  and  sown  on  recently  stirred  soil, 
and  covered  to  different  depths,  accord- 
ing to  the  size  of  the  seed,  the  nature  of 
the  soil  and  situation,  and  other  circum- 
stances. The  plants  formed  by  runners 
are  separated  from  the  parent  plant  by 
cutting  through  the  runner,  and  remov- 
ing the  young  plant,  in  order  to  plant  it 
elsewhere.  Suckers,  slips,  or  side-shoots 
from  the  roots,  are  separated  from  the 
parent  plant  by  being  slipped  down,  or 
cut  otf,  so  as  to  carry  with  them  a  por- 
tion of  fibrous  roots  ;*.and  they  are  aitcr- 
wards  planted  in  suitable  soil,  &c.  Off- 
sets are  small  bulbs  which  are  produced 
round  the  base  of  larger  ones,  and,  being 
taken  off  and  planted,  become  plants. 
Tubers  are  underground  stems,  contain- 
ing leaf-buds ;  and  these  may  be  sepa- 
rated and  planted  entire,  or  cut  into  as 
many  pieces  as  there  are  buds,  in  either 
of  which  cases  new  plants  will  be  form- 
ed. Layers  are  branches  or  shoots  of 
either  woody  or  herbaceous  plants,  which 
are  bent  down,  and  a  portion  of  their 
length  buried  a  few  inches  in  the  soil ; 
that  portion  having  been  previously 
wounded  by  cutting,  bruising,  or  twist- 
ing, which,  by  checking  the  descent  of 
the  sap,  gives  rise,  after  a  certain  period, 
to  the  production  of  roots.  After  these 
roots  are  formed,  the  portion  of  the  layer 
which  has  produced  them  is  separated 
from  the  main  stock  or  parent  plant,  and 
planted  by  itself.  Cuttings  are  portions 
of  shoots,  either  of  ligneous  or  herbace- 
ous plants ;  and  they  are  made  of  the 
young  shoots  with  the  leaves  on,  or  of  the 
ripened  wood  either  with  or  without  its 
leaves ;  and  after  they  have,  either  in  a 
herbaceous  state  with  the  leaves  on,  or 
with  the  wood  mature  and  with  or  with- 
out the  leaves,  been  properly  prepared 
and  planted,  they  form  roots  at  their 
lower  extremity,  each  cutting  becoming  a 
perfect  plant.  In  general,  cuttings  should 
be  taken  from  those  shoots  of  a  plant 
which  are  nearest  the  soil ;  because,  from 
the  moisture  and  shade  there,  such  shoots 
are  more  predisposed  to  emit  roots  than 
those  on  the  upper  part  of  the  plant. 
The  young  or  last- formed  shoots  are  to 
be  taken  in  preference  to  such  as  are 
older,  as  containing  more  perfect  buds  in 
an  undeveloped  state,  and  a  bark  more 
easily  permeable  by  roots  ;  and  the  cut- 
ting is  to  be  prepared  by  cutting  its  lower 
extremity  across  at  a  joint,  the  lenticells 


or   root-buds  being  there    most  abun- 
dant. 

PRUNING.  The  art  of  cutting  off 
parts  of  plants,  and  more  especially  of 
trees  and  shrubs,  with  a  view  to  strength- 
ening those  which  remain,  or  of  bringing 
the  tree  or  plant  into  particular  forms, 
calculated  to  increase  particular  products. 
Pruning,  therefore,  varies  according  to 
the  kind  of  plant  or  tree  to  be  pruned, 
and  according  to  the  object  in  view.  In 
the  case  of  forest  trees,  the  general  object 
of  pruning  is  to  increase  the  quantity  of 
timber  in  the  trunk  by  diminishing  the 
side  branches,  commencing  at  the  lower 
part  of  the  tree  when  it  is  quite  young, 
and  gradually  advancing  upwards  as  the 
tree  increases  in  growth.  In  the  case  of 
hedges,  the  object  is  to  produce  a  dense 
mass  from  the  ground  upwards,  which  is 
eti'ected  by  shortening  the  side  branches. 
In  the  case  of  pruning  trees  which  are 
cultivated  for  the  sake  of  their  fruit  or 
blossoms,  the  object  is  to  thin  out  the 
branches  so  as  to  admit  the  light  and  air 
more  freely  to  their  leaves  and  blossoms, 
and  to  concentrate  and  increase  the  nou- 
rishment to  the  branches  which  remain. 
In  the  case  of  trees,  or  shrubs  cultivated 
for  the  beauty  of  their  shapes,  whether 
natural  or  artificial,  the  object  of  pruning 
is  to  deprive  the  trees  or  shrubs  of  all 
those  branches  which  deviate  from  or 
interfere  with  the  natural  shape,  or  with 
the  form  which  is  intended  to  be  pro- 
duced by  art.  In  pruning  with  a  view 
to  produce  fruit,  it  is  necessary  to  know 
on  what  description  of  branches  and  buds 
the  fruit  is  produced.  In  some  trees,  as 
in  the  peach,  it  is  generally  produced  on 
the  wood  of  the  preceding  year ;  in  others, 
as  in  the  apple  and  pear,  it  is  generally 
produced  on  wood  of  two  years'  growth  ; 
and  in  the  vine  it  is  produced  on  shoots 
of  the  current  year.  The  general  eflect 
of  pruning  on  plants  is  to  increase  their 
longevity ;  since  the  tendency  of  all  vege- 
tables is  to  exhaust  themselves,  and,  con- 
sequently, to  shorten  their  duration,  by 
the  production  of  seeds.  In  the  opera- 
tion of  pruning,  the  shoots  are  cut  off 
close  to  the  buds,  or  at  a  distance  from 
them  not  greater  than  the  diameter  of  the 
branch  to  be  cut  oil';  because,  without 
the  near  proximity  of  a  bud,  the  wounds 
will  not  heal  over.  In  shoots  which  pro- 
duce their  buds  alternately,  the  cut  is 
made  at  the  back  of  the  bud,  sloping 
from  it,  so  as  that  it  may  be  readily 
covered  by  bark  in  the  same  or  in  the 
following  year.  This  is  readily  done 
with  a  pruning  knife,  by  a  slanting  cut, 


PRU] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


501 


made  at  an  angle  of  45°  with  the  direc-  | 
tion  of  the  branch ;  but,  in  the  case  of 
branches  where  the  buds  are  produced 
opposite  each  other,  either  one  bud  must 
be  sacrificed,  or  the  branch  must  be  cut 
off  at  right  angles  to  its  line  of  direction ; 
and  is  more  conveniently  done  by  the 
pruning  shears.  The  operation  of  prun- 
ing may  in  many  cases  be  superseded  by 
rubbing  off,  or,  pinching  out,  the  leaf- 
buds,  so  as  to  prevent  superfluous  shoots 
from  being  produced. 

PEUSSIATE  OF  POTASH,  or  Fer- 
rocyanide  of  Potassium.  The  ferrocy- 
anuret  of  potassium  is  prepared  by  gently 
igniting  carbonate  of  potassa  with  animal 
matters,  such  as  horns,  hoofs,  or  dried 
blood,  in  iron  vessels,  by  which  cyanuret 
of  potassium  and  some  cyanuret  of  iron 
are  formed ;  the  soluble  parts  are  then 
washed  out  with  water,  and  sulphate  of 
iron  added  until  the  Prussian  blue  which 
is  formed  ceases  to  be  decomposed  by  the 
free  potassa  contained  in  the  solution  ; 
the  terrocyanuret  of  potassium  is  then 
set  to  crystallize,  and  separated  by  re- 
peated crystallization  from  sulphate  of 
potassa.  It  is  thus  obtained  in  truncated 
octohedral  crystals  of  a  yellow  color,  com- 
monly called  Prussiate  of  potash.  It  is 
much  used  in  chemistry  as  a  test  for  the 
metals. 

PRUSSIAN  BLUE.  This  salt  is  made 
by  adding  solution  of  a  salt  of  iron  to  a 
solution  of  prussiate  of  potash.  Green  sul- 
phate of  iron  is  always  employed  by  the 
manufacturer,  on  account  of  its  cheapness, 
for  mixing  with  solution  of  the  ferroprus- 
siate,  in  forming  Prussian  blue,  though 
the  red  sulphate,  nitrate,  or  muriate  of 
iron  would  afford  a  much  richer  blue 
pigment.  Whatever  salt  of  iron  be  pre- 
ferred, should  be  carefully  freed  from 
any  cupreous  impregnation,  as  this  would 
give  the  pure  blue  a  dirty  brownish  cast. 
The  green  sulphate  of  iron  is  the  most 
advantageous  precipitant,  on  account  of 
its  affording  protoxide,  to  convert  into 
ferrocyanide  any  cyanide  of  potassium 
that  may  happen  to  be  present  in  the 
uncrystallized  lixivium.  The  carbonate 
of  potash  in  that  iixivium  might  be  satu- 
rated with  sulphuric  acid  before  adding 
the  solution  of  sulphate  of  iron  ;  but  it  is 
more  commonly  done  by  adding  a  certain 
portion  of  alum  ;  in  which  case,  alumina 
falls  along  with  the  Prussian  blue ;  and 
though  it  renders  it  somewhat  paler,  yet 
it  proportionally  increases  its  weight; 
whilst  the  acid  of  the  alum  saturates  the 
carbonate  of  potash,  and  prevents  its 
throwing  down  iron-oxide,  to  degrade 


by  its  brown-red  tint  the  tone  of  the 
blue.  For  every  pound  of  pearlash  used 
in  the  calcination,  from  two  to  three 
pounds  of  alum  are  employed  in  the  pre- 
cipitation. When  a  rich  blue  is  wished 
for,  the  free  alkali  in  the  Prussian  ley 
may  be  partly  saturated  with  sulphuric 
acid,  before  adding  the  mingled  solutions 
of  copperas  and  alum.  One  part  of  the 
sulphate  of  iron  is  generally  allowed  for 
15  or  20  parts  of  dried  blood,  and  2  or  3 
of  horn-shavings  or  hoofs.  But  the  pro- 
portion will  depend  very  much  upon  the 
manipulations,  which,  if  skilfully  con- 
ducted, will  produce  more  of  the  cyan- 
ides of  iron,  and  require  more  copperas 
to  neutralize  them.  The  mixed  solutions 
of  alum  and  copperas  should  be  progres- 
sively added  to  the  ley  as  long  as  they 
Sroduce  any  precipitate.  This  is  not  at 
rst  a  fine  blue,  but  a  greenish  gray,  in 
consequence  of  the  admixture  of  some 
white  cyanide  of  iron ;  it  becomes  gradu- 
ally blue  by  the  absorption  of  oxygen 
from  the  air,  which  is  favored  by  agita- 
tion of  the  liquor.  Whenever  the  color 
seems  to  be  as  beautiful  as  it  is  likely  to 
become,  the  liquor  is  to  be  run  off  by  a 
spigot  or  cock  from  the  bottom  of  the 
precipitation  vats,  into  flat  cisterns,  to 
settle.  The  clear  supernatant  fluid, 
which  is  chiefly  a  solution  of  potash,  is 
then  drawn  off  by  a  syphon ;  more  water 
is  run  on  with  agitation  to  wash  it,  which 
after  settling  is  again  drawn  off;  and 
whenever  the  washings  become  tasteless, 
the  sediment  is  thrown  upon  filter  sieves, 
and  exposed  to  dry,  first  in  the  air  of  a 
stove,  but  finally  upon  slabs  of  chalk  or 
Paris  plaster.  But  for  several  purposes, 
Prussian  blue  may  be  best  employed  in 
the  fresh  pasty  state,  as  it  then  spreads 
more  evenly  over  paper  and  other  sur- 
faces. 

A  good  article  is  known  by  the  follow- 
ing tests:  it  feels  light  in  the  hand, 
adheres  to  the  tongue,  has  a  dark  lively 
blue  color,  and  gives  a  smooth  deep 
trace;  it  should  not  effervesce  with  acids, 
as  when  adulterated  with  chalk;  nor  be- 
come pasty  with  boiling  water,  as  when 
adulterated  with  starch!  The  Paris  blue, 
prepared  without  alum,  with  a  peroxide 
salt  of  iron,  displavs,  when  rubbed,  a 
copper-red  lustre,  like  indigo.  Prussian 
blue,  degraded  in  its  color  by  an  admix- 
ture of  free  oxide  of  iron,  may  be  im- 
proved by  digestion  in  dilute  sulphuric 
or  muriatic  acid,  washing,  and  ctrying. 
Its  relative  richness  in  the" real  ferroprus- 
siate  of  iron  may  be  estimated  by  the 
quantity  of  potash  or  soda  which  a  given 


502 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[pud 


quantity  of  it  requires  to  destroy  its  blue 
color. 

Sulphureted  hydrogen  passed  through 
Prussian  blue  diffused  in  water,  whitens 
it ;  while  prussic  acid  is  eliminated,  sul- 
phur is  thrown  down,  and  the  sesquicy- 
anide  of  iron  is  converted  into  the  single 
cyanide.  Iron  and  tin  operate  in  the 
same  way.  When  Prussian  blue  is  made 
with  two  atoms  of  ferrocyanide  of  potas- 
sium, instead  of  one,  it  becomes  soluble 
in  water.  The  following  process  deserves 
peculiar  notice,  as  the  first  in  which  this 
interesting  compound  has  been  made  to 
any  extent,  independently  of  animal 
matter.  Mr.  Lewis  Thompson,  of  Lam- 
beth, received  a  well-merited  medal  from 
the  Society  of  Arts  for  this  invention. 
He  observed  that  in  the  common  way  of 
manufacturing  prussiate  of  potash,  the 
quantity  of  nitrogen  furnished  by  a  given 
weight  of  animal  matter  is  not  large,  and 
seldom  exceeds  8  per  cent. ;  and  of  this 
small  quantity,  at  least  one  half  appears 
to  be  dissipated  during  the  ignition.  It 
occurred  to  him  that  the  atmosphere 
might  be  economically  made  to  supply 
the  requisite  nitrogen,  if  caused  to  act  in 
favorable  circumstances  upon  a  mixture 
of  carbon  and  potash.  He  has  found  the 
following  prescription  to  answer :  Take 
of  pearlash  and  coke,  each  two  parts ; 
iron  turnings,  one  part ;  grind  them  to- 
gether into' a  coarse  powder  ;  place  this 
in  an  open  crucible,  and  expose  the 
whole  for  half  an  hour  to  a  full  red  heat 
in  an  open  fire,  with  occasional  stirring 
of  the  mixture.  During  this  process, 
little  jets  of  purple  flame  will  be  observed 
to  rise  from  the  surface  of  the  materials. 
When  these  cease,  the  crucible  must  be 
removed  and  allowed  to  cool.  The  mass 
is  to  be  lixiviated ;  the  lixivium,  which 
is  a  solution  of  ferrocyanide  of  potassium, 
with  excess  of  potash,  is  to  be  treated  in 
the  usual  way,  and  the  black  matter  set 
aside  for  fresh  operation  with  a  fresh 
dose  of  pearlash.  Mr.  Thompson  states 
that  one  pound  of  pearlash,  containing 
45  per  cent,  of  alkali,  yielded  1,355  grains 
of  pure  Prussian  blue',  or  ferrocyanide  of 
iron  ;  or  about  3  ounces  avoirdupoise. 

PKUSSIC  ACID.  Hydrocyanic  or 
prussic  acid,  which  consists  of  1  atom  of 
cyanogen=26,+l  at.  of  hydrogen  =  1,  is 
prepared  by  distilling  the  mercurial  bi- 
cyanide  in  a  glass  retort  with  the  saturat- 
ing quantity  of  dilute  muriatic  acid. 
Prussic  acid  may  also  be  obtained  by 
precipitating  the  mercury  by  sulphureted 
hydrogen  gas  from  the  solution  of  its  cy- 
anide ;  as  also  by  distilling  the  ferrocya- 


nide of  potassium  along  with  dilute  sul- 
phuric acid.  Piussic  acid  is  a  very  vola- 
tile light  fluid,  eminently  poisonous,  and 
is  spontaneously  decomposed  by  keeping, 
especially  when  somewhat  concentrated. 

Prussic  acid  is  also  obtained  by  expos- 
ing the  horns,  hoofs,  and  dried  blood  of 
animals,  with  fixed  alkali  to  a  red  heat. 
United  with  iron  it  is  Prussian  blue,  and 
for  experiments  may  be  abstracted  from 
that  pigment.  A  dog's  palate  being 
touched  with  a  glass  rod  dipped  in  it, 
the  animal  falls  dead  instantly,  and  such 
are  its  usual  effects  on  animal  life. 

Prussic  acid  exists  in  the  skin  of  the 
kernel  of  the  seeds  which  produce  it,  as 
bitter  almonds,  the  cherry-laurel,  &c, 
&c.  It  is  a  compound  of  carbon  and  ni- 
trogen, called  cyanogen,  with  hydrogen, 
and  hence  called  hydro-cyanic  acid.  It 
operates  in  medicine  in  very  small  doses, 
on  the  principle  of  allaying  irritability 
without  disturbing  respiration. 

The  tests  commonly  employed  for  the 
detection  of  prussic  acid,  are"  the  smell, 
the  taste,  and  the  reaction  of  the  suspect- 
ed substance  on  the  addition  of  certain 
saline  solutions — viz.  the  solution  of  ni- 
trate of  silver,  sulphate  of  copper,  and  of 
any  salt  of  iron  containing  the  black  ox- 
ide of  that  metal.  Of  these  tests  the  most 
delicate,  but  perhaps  least  certain,  is  the 
sense  of  smell :  while  the  ferruginous  so- 
lution, one  of  the  least  delicate,  is,  per- 
haps, the  most  certain  of  all. 

PUDDLING.  This  process  has  been 
explained  under  Ikon  manufacture.  In- 
stead of  heat,  electricity  is  now  brought 
into  play  to  effect  the  object,  namely,  the 
decarbonization  and  purification  of  the 
metal.  A  great  economy  in  the  conver- 
sion of  the  cast  into  wrought  metal  seems 
about  to  be  effected  in  our  iron  works, 
by  the  application  of  a  current  of  voltaic 
electricity  to  the  crude  iron  in  a  state  of 
fusion,  whether  on  the  hearth  of  the  blast 
furnace,  on  the  fused  pigs  in  the  sand,  or 
on  the  metal  immediately  on  its  being 
run  from  the  finery  furnace  ;  the  voltaic 
force  of  from  50  to'lOO  pairs  of  a  power- 
ful Smee's  battery  being  previously  ar- 
ranged to  act  upon  the  whole  train  of  the 
metal.  This  process,  for  which  Mr.  Ar- 
thur Wall  has  recently  obtained  a  patent, 
is  founded  upon  the  well-established  fact, 
that  when  a  compound  is  subjected  to  an 
electrical  current,  its  negative  and  posi- 
tive elements  are  detached  from  one  ano- 
ther. Crude  iron  contains  more  or  Jess 
carbon,  sulphur,  phosphorus,  arsenic, 
oxygen,  ana  silicon — bodies  all  electro- 
negative in  relation  to  iron,  which  is  elec- 


ptjl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


503 


tro-positive.  When  the  impure  iron,  as 
it  flows  from  the  blast  furnaces,  is  sub- 
jected during  its  cooling  and  consolida- 
tion to  a  powerful  stream  of  voltaic  elec- 
tricity, the  chemical  affinities  by  which 
its  various  heterogeneous  components 
are  firmly  associated,  are  immediately 
subverted,  whereby,  in  the  case  of  crude 
iron,  the  sulphur,  phosphorus,  &c, 
which  destroy  or  impair  its  tenacity  and 
malleability,  become  readily  separable  in 
the  act  of  puddling. 

The  pecuniary  advantage  of  this  pro- 
cess, in  respect  of  saving  of  labor  and 
waste  of  material,  has  been  estimated  by 
competent  judges  at  from  five  to  ten 
dollars  per  ton. 

The  effect  of  electrising  iron  is  display- 
ed in  a  singular  manner  by  the  conver- 
sion into  steel  of  a  soft  rod,  exposed  in 
contact  with  coke,  for  a  few  hours,  to  a 
moderate  red  heat. 

PULLEY.  In  mechanics,  one  of  the 
six  simple  machines,  or  mechanical  pow- 
ers. It  consists  of  a  wheel,  movable 
about  an  axis,  and  having  a  groove  cut  in 
its  circumference,  over  which  a  cord 
passes.  The  axle  is  supported  by  a  box 
or  sheave,  called  the  block,  which  may 
either  be  movable,  or  fixed  to  a  firm 
support. 

A  single  pulley  serves  merely  to  change 
the  direction  of  motion ;  but  several  of 


Fig.  1. 


them  may  be  combined  in  va- 
rious ways,  by  which  a  me- 
chanical advantage  or  purchase 
is  gained,  greater  or  less,  ac- 
cording to  their  number  and 
the  mode  of  combination.  The 
purchase  gained  by  any  com- 
bination is  readily  computed 
wvjk//  by  comparing  the  celerity  of 
^  the  weight  raised  with  that  of 

$  the  moving  power,  according 

to  the  principle  of  virtual  ve- 
locities, which  is  alike  appli- 
F<2>  cable  to  all  machines  of  what- 
ever kind.  In  fig.  1,  which  represents  a 
system  where  the  several  portions  of  the 
cord  are  parallel  to  each  other,  suppose 
the  weight  W  to  rise  one  inch,  the  two 
blocks  would  approach  each  other  by  that 
quantity,  and  consequently,  the  length  of 
cord  connecting  a  single  pair  of  pulleys 
would  be  shortened  by  2  inches,  so  that 
the  power  P  would  descend  2  inches. 
Let  the  number  of  pulleys  in  each  block 
be  n  ;  then,  while  the  weight  ascends  1 
inch,  the  power  descends  2  winches,  and, 
v,  when  there  is  equilibrium,  the  power 
is  to  the  weight  as  1  to  2  n. 
In  the  combination  represented  in  fig. 


2,  the  purchase  is  much  greater.  Here 
the  pulleys  are  all  movable,  and  each  is 
Fig.  2.  supported  by  a  separate  cord, 
having  one  end  fastened  to  a 
fixed  obstacle  and  the  other 
attached  to  the  succeeding 
pulley,  excepting  the  upper 
block,  which  is  fixed.  It  is 
evident  that,  for  every  inch 
the  weight  on  the  first  pul- 
ley a  ascends,  the  second,  b, 
ascends  two  ;  the  third,  c, 
ascends  four,  and  so  on  ;  the 
velocity  being  doubled  by  each  additional 
pullev.  The  purchase  finally  obtained  is, 
therefore,  =2" ;  or  the  power  is  to  the 
weight  as  1  :  2n. 

The  third  combination,  fig.  3,  has  still 
greater  efficacy.  In  this  system,  each 
cord  is  fastened  to  the  weight,  and,  pass- 
Fi"  3  ing  over  a  pulley,  is  attached 
to  another  pulley,  excepting 
the  last,  which  supports  the 
power.  While  the  weight  W 
rises  1  inch,  the  first  movable 
pulley,/,  will  sink  1  inch,  which 
allows  the  cord  applied  to  it  to 
slacken  2  inches,  and  this  join- 
ed to  the  inch  which  the  weight 
ascends  allows  the  second  mo- 
vable pulley,  g,  to  descend  3  inches. 
This  allows  the  next  pulley  in  succession 
to  descend  6  inches,  which,  joined  to  the 
1  inch  which  the  weight  ascends,  gives  7 
inches  for  the  descent  of  the  third  pulley. 
In  like  manner,  it  is  found  that  the  de- 
scent of  the  fourth  pulley  is  15  inches. 
Hence,  one  movable  pulley  allows  the 
weight  to  descend  2X1  +  1  =  3  inches  ; 
two  such  pulleys,  2X3  +  1  =  7  inches  ; 
3  pulleys,  2  X  7  +  1  =  15  inches  ;  four 
pulleys,  2  X  15  +  1  =  31  inches,  and  so 
on  ;  so  that  the  purchase  obtained  by  n 
movable  pulleys,  is  2«  +  1  —  1,  or  the 
power  is  to  the  weight  as  1  to  2n  +  l  —  1. 
The  theoretical  advantage  thus  computed 
is,  however,  in  all  the  cases,  greatly  di- 
minished by  friction,  and  the  rigidity  of 
the  rope. 

The  two  last  combinations  are  of  little, 
if  any,  use  in  practice,  but  various  modi- 
fications of  the  first  are  common.  Smea- 
toti's  pulley,  or  Smeaton's  tack,  as  it  is  usu- 
ally called,  contains  two  rows  of  wheels, 
one  under  the  other,  in  each  block,  and  a 
single  cord  is  made  to  pass  over  them  in 
such  a  manner  that  the  power  and  the 
weight  both  act  in  the  same  line  with  the 
centres  of  the  two  blocks,  so  that  there  is 
no  tendency  to  twist.  But  this  ingenious 
arrangement  is  open  to  several  objections, 
and  particularly  the  great  amount  of  lator- 


504 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PUM 


al  friction  of  so  many  independent  wheels. 
In  White's  pulley  (see  fig.  1.)  the  wheels 
in  each  block  turn  on  the  same  axis,  and, 
consequently,  revolve  in  the  same  time ; 
and  they  are  of  different  sizes,  their  di- 
mensions being  so  proportioned  that  a 
point  on  the  circumference  of  any  wheel 
moves  with  the  velocity  of  the  rope  on 
that  wheel.  To  effect  this  the  diameter 
of  the  wheels  in  the  upper  block  must  be 
as  the  numbers,  1,  3,  5,  &c,  and  in  the 
lower  as  2,  4,  6,  &c.  Instead  of  separate 
wheels,  the  upper  and  lower  blocks  are 
cut  in  grooves  in  the  above  proportions, 
whereby  the  friction  is  reduced  to  that  of 
one  wheel  in  each  block. 

PUMICE.  A  substance  frequently 
ejected  from  volcanoes,  of  various 
colors,  gray,  white,  reddish  brown,  or 
black ;  hard,  rough  and  porous ;  spe- 
cifically lighter  than  water,  and  resem- 
bling the  slag  produced  in  an  iron  furnace. 
It  consists  of  parallel  fibres,  and  is  sup- 
posed to  be  asoestos  decomposed  by  the 
action  of  fire.  Pumice  is  of  three  kinds, 
glassy,  common,  and  porphyritic.  It  is 
used  for  polishing  ivory,  wood,  marble, 
metals,  glass,  &c. ;  as  also  skins  and 
parchment.  It  is  useful  in  cleaning  cloth, 
and  affording  surface  for  decomposition 
in  retorts  ;  it  consists  chiefly  of  alumina. 
PUMP.  A  machine  for  raising  water. 
Though  the  forms  under  which  this  use- 
ful engine  is  constructed,  and  the  mode 
in  which  the  power  is  applied,  may  be 
modified  in  an  infinite  number  of  ways, 
there  are  only  three  which  can  be  consi- 
dered as  differing  from  each  other  in 
principle.  These  are,  the  sucking  pump, 
the  forcing  pump,  and  the  lifting  pump, 
so  called  from  the  manner  in  which  they 
act. 

The  sucking  pump,  or  common  house- 
hold pump,  is  an  apparatus  of  which  the 
principle  and  construction  will  be  evident 
Fig.  1.  from  tne  annexe(i  figure.  A  A 
is  a  pipe  of  any  convenient 
length,  the  lower  end  of  which 
reaches  below  the  surface  of  the 
water  in  the  well  or  reservoir ; 
B  is  a  barrel,  generally  of  great- 
er diameter  than  the  pipe  ;  C  a 
valve  opening  upwards  ;  D  a 
piston  moved  by  the  rod  E :  in 
this  piston  there  is  also  a  valve 
opening  upwards.  When  the 
piston  is  raised,  the  air  in  the 
I  barrel  between  the  valves  is  ex- 
panded, and  its  tension,  consequently, 
diminished  ;  the  pressure  of  the  air  in 
the  pipe,  therefore,  opens  the  valve  C. 
and  the  whole  air  in  the  pipe  and  barrel 


becomes  less  dense.  In  this  state  the  at- 
mospheric pressure  on  the  surface  of  the 
water  causes  it  to  rise  in  the  pipe,  until 
the  tension  of  the  confined  air  becomes 
equal  to  the  pressure  of  the  atmosphere. 
On  again  depressing  the  piston,  the  valve 
in  it  opens,  and  the  air  passes  through  it 
from  the  barrel  as  it  descends ;  but  the 
valve  C  is  closed  by  the  downward  pres- 
sure, and  the  volume  of  water  which  has 
entered  the  pipe  remains.  On  again  rais- 
ing the  piston,  the  same  effect  is  repeated, 
and  an  additional  quantity  of  water  en- 
ters the  nipe.  Thus,  by  the  alternating 
motion  of  the  piston,  a  column  of  water  is 
raised  in  the  pipe  until  it  reaches  the  pis- 
ton when  at  the  bottom  of  the  barrel,  and 
the  whole  of  the  air  below  it  has  been  ex- 
cluded. On  raising  the  piston  when  the 
water  has  reached  it,  the  fluid  will  be 
compelled  to  follow  by  the  pressure  of 
the  atmosphere  on  its  surface  in  the  well. 
When  the  piston  is  again  depressed,  the 
water  flows  through  the  valve  in  it,  and 
ascends  into  the  barrel,  and  by  the  suc- 
ceeding strokes  of  the  piston  is  lifted  up 
until  it  reaches  and  flows  out  of  the  spout 
F. 

Although  in  theory  the  limit  of  the 
height  to  which  water  may  be  raised  by 
the  sucking  pump,  from  the  surface  of 
the  fluid  in  the  well  to  the  highest  posi- 
tion of  the  movable  piston,  is  about  34 
feet,  (the  height  of  a  column  of  water 
which  balances  the  pressure  of  the  at- 
mosphere), it  is  not  found  practicable, 
with  pumps  of  the  ordinary  construction, 
to  raise  it  more  than  about  28  feet.  The 
difference  arises  from  the  difficulty  of 
making  the  apparatus  absolutely  air- 
tight. 

The  chain  pump  used  in  ships  of  war 
consists  of  an  endless  chain  moving  over 
a  wheel  on  the  gun-deck,  which  is  turned 
by  winches,  and  over  a  roller  in  the  pump- 
well,  having  saucers  or  flat  circular  pistons 
at  certain  intervals.  Near  the  pump-well, 
on  the  side  on  which  the  chain  on  turn- 
ing the  winches  ascends,  are  a  few  feet 
of  pipe ;  through  this  the  saucers  raise 
the  column  of  water,  which,  being  lifted 
over  the  upper  orifice  of  the  pipe,  falls 
into  the  cistern,  and  thence  into  the 
waste-pipe,  called  the  pump-dale,  which 
carries  it  overboard.  The  descending 
portion  of  chain  falls  through  another 
case  called  the  back  case.  Chain  pumps, 
in  large  ships,  throw  out  a  ton  a  minute. 

The  forcmg  pump  is  represented  at  fig. 
2.  The  piston-rod  E  1)  is  attached  to  a 
solid  plunger  D,  adjusted  to  the  cavity  of 
the  barrel.    A  pipe  G.  H,  furnished  with 


pum] 


CYCLOPEDIA    OP"    THE    USEFUL    ArvTS. 


505 


a  valve  F,  opening  outwards,  communi- 
cates with  the  barrel  at  G.  On  elevating 
the  plunger  D,  the  water  will  ascend 
through  the  valve  C,  in 
the  same  manner  as  in 
the  sucking  pump,  till 
the  barrel  is  filled  to  D. 
Now,  when  the  plunger 
is  depressed,  the  vaive 
C  will  shut,  and  the 
water  between  D  and  C 
be  forced  through  the 
valve  F  into  the  pipe  G 
H.  When  the  plunger 
is  raised,  the  valve  at  F 
shuts,  the  pressure  on 
its  under  side  being  re- 
moved, so  that  the  water 
which  was  forced  into  the  pipe  by  the 
previous  stroke  cannot  return  into  the 
barrel.  At  the  next  stroke  of  the  piston, 
more  water  is  again  forced  into  the  pipe, 
and  so  on  till  it  is  raised  to  the  height  re- 
quired. 

In  this  pump  the  pipe  A  A  may  be  dis- 
pensed with,  and  the  barrel  B  immersed 
in  the  reservoir  ;  in  which  case  the  action 
of  the  pump  is  independent  of  the  atmos- 
pheric pressure,  and  could  be  maintained 
equally  well  in  a  vacuum. 

In  order  to  produce  a  continued  stream 


Fig.  3. 


through  the  pipe  G  II, 
an  air  vessel,  m  n,  may 
be  attached  to  the  late- 
ral branch  above  the 
valve  F,  fig.  3.  The 
pipe  G  II  reaches  too 
near  the  bottom  of  the 
air  vessel  ;  and  when 
the  water  has  been 
forced  into  the  vessel 
by  the  action  of  the 
pump,  until  it  reaches 
above  the  lower  end  of 
the  pipe  at  G,  it  is  evident  that,  as  all 
communication  is  then  cut  off  with  the 
external  atmosphere,  every  additional 
quantity  of  water  thrown  into  the  vessel 
will  tend  more  and  more  to  compress  the 
air  within  it,  which,  acting  by  its  pres- 
sure on  the  surface  of  the  water,  forces  it 
through  the  pipe  G  H  in  a  continued 
stream. 

The  lifting  pump  is  represented  by  fig. 
4.  The  barrel  of  the  pump  is  immersed 
in  the  water  and  fixed  to  an  immovable 
frame.  The  piston  with  its  bucket  and 
valve  C,  opening  upwards,  is  attached  at 
E  to  another  frame,  G  H I  K  L,  consist- 
ing of  two  strong  iron  rods,  H  I  and  L  K, 
which  move  through  holes  in  the  frame- 
work to  which  the  pump  is  fixed.    An 


•  inclined  branch  M  N,  either  fixed  to  the 

top  of  the  barrel,  or  movable 
|  by  means  of  a  ball  and  socket, 
is  fitted  exactly  to  the  barrel, 
and  furnished  with  a   valve 
i  at   M.     Suppose  the   barrel 
|  immersed  in  the  water  to  a 
1  certain  depth  :  if  the  piston 
frame  be  now  thrust   down 
I  by  the  handle  at  G,  the  pis- 
ton will  descend,  and  the  wa- 
ter be  forced  by  its  upward 
pressure  through  the  valve 
C,    so    as    to   maintain  the 
level  in  the  pump  as  in  the  well.    But 
when  the  piston  frame  is  elevated,  the 
valve   C   will  shut    (as    shown    in    th% 
figure),  and  the  water  above  C  be  lifted, 
up  with  the  piston,  and  forced  through 
.  the  valve  M  into  the  branch  M  N,  from 
which  its  return  will  be  prevented  by  the 
shutting  of  the  valve  M  when  the  piston 
descends. 

In  each   of  these  different  kinds  of 
pumps  which  have  been  described,  the 
total  effort  required  to  work  the  machine, 
independently  of  friction,  is  equal  to  the 
weight  of  a  column  of  water,  the  base  of 
which  is  equal  to  the  area  of  a  section  of 
the  working  barrel,  and  the  altitude  equal 
to  the  distance  between  the  surface  of  the 
water  in  the  reservoir  and  the  point  to 
which  it  is  raised.    In  the  sucking  pump 
the  whole  of  this  effort  is  expended  in 
raising  the  piston  :  in  the  forcing  pump 
one  part  is  expended  in  raising  and  the 
other  in  depressing  the  piston,  and  it  is 
advantageous  to  dispose  the  machinery 
so  that  these  two  parts  shall  be  nearly 
equal.    In  small  pumps  for  domestic  pur- 
poses, the  strength  of  man  is  usually  em- 
ployed as  the  moving  power ;  but  in  rais- 
ing water  from  great  depths,  as  the  bot- 
tom of  mines,  the  steam-engine  is  appli- 
ed to  this  purpose.     (See  Fike  Engine.) 
Mr.  Von  Schmidt,  of  New- York,  has 
I  patented  a  centrifugal  pump,  which  works 
j  thus :     There  are  two  circular  flanges 
|  which  are  bolted  together  and  form  a 
I  hollow  ring,  with  the  sides,  like  two  discs 
j  bolted  together,  forming  a  hollow  cham- 
[  ber  within,  and  having  a  wide  circular 
I  circumferential  chamber  (hollow  ring). 
There  is  an  orifice  of  discharge,  to  which 
a  pipe  may  be  attached,  and  a  pipe  for  a 
lower  orifice  on  the  other  side  communi- 
cates,  air-tight,   with  the  water  in  the 
well,   or  other  place.    The   shaft   runs 
through  the  pump,  and  has  a  stuffing 
box  to  render  it  air-tight  when  it  passes 
into  and  out  of  the  circular  chamber,  a 
large  pulley  aided  by  a  band  from  any 


506 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[put 


power  revolves  the  arms  inside  to  raise 
and  fon?.e  the  -water.  The  blades  of  the 
amis  run  in  the  circumference  or  hollow 
ring,  and  the  arms  revolve  between  the 
two  sides.  The  blades  are  not  stuffed 
nor  fitted  to  run  stiffly  in  the  hollow  ring, 
a  thing  common  to  other  rotary  pumps, 
and  which  causes  much  friction,  a  rapid 
wear  of  rubbing  surface,  and  hence  con- 
signs them  to  an  early  tomb.  It  is,  on 
the  other  hand,  fitted  to  run  with  ease, 
like  a  blower ;  so  that  its  passages  do  not 
get  clogged  up,  and  sand,  gravel,  &c,  do 
not  injure  it.  It  requires  no  inside  pack- 
ing ;  all  the  parts  are  simple,  easily  cast 
and  put  together.  Pumps  of  this'  kind 
are  made  capable  of  discharging  from  5 
gallons  to  5,000  gallons  of  water  per  min- 
ute with  suction  pipe  of  wrought  or 
cast  iron,  copper  or  lead,  or  flexible  pipe 
of  leather  or  India  rubber;  also  discharge 

J  ripe  of  iron,  copper  or  lead,  and  hose  of 
eather,  India  rubber,  or  gutta  percha. 
It  is  both  a  suction  and  force  pump ;  and 
may  be  used  as  a  fire  engine  by  simply 
attaching  hose  to  the  discharge-pipe  :  by 
increasing  the  power,  the  "quantity  of 
water  discharged  will  increase  proportion- 
ately. Its  movement  being  rotary,  this 
increase  may  be  indefinite ;  or  up  to  the 
point  of  velocity  with  which  water  will 
fill  a  vacuum.  It  has  been  adopted  by 
the  United  States  government  in  the 
construction  of  the  Water  Battery  on 
Staten  Island,  harbor  of  New-York,  and 
at  the  extensive  fortifications  now  in  pro- 
gress on  the  Tortngas  Keys,  Florida,  and 
it  is  useful  for  almost  every  hydraulic 
purpose. 

PURIFICATION  of  Gold  and  Silver, 
by  antimony.  (Under  the  article  Assay 
and  Metallurgy,  this  has  been  partly 
treated  of.)  The  gold  is  to  be  melted  in 
a  crucible  large  enough  to  contain  thrice 
the  quantity  of  metal.  When  the  gold  is 
melted,  twice  its  weight  of  sulphuret  of 
antimony  powdered  is  to  be  thrown  upon 
it,  the  crucible  is  to  be  covered,  and  left 
some  minutes  in  fusion ;  after  which, 
when  the  mixture  is  well  fused,  and  so 
hot  that  its  surface  sparkles,  it  is  quickly 
to  be  poured  into  an  iron  cone,  previous- 
ly heated  and  greased.  This  matter  con- 
sists, when  cold,  of  two  substances  :  the 
upper  one  of  the  sulphur  of  the  antimony, 
united  with  the  metals  with  which  the 
gold  was  alloyed,  and  the  lower  is  the 
gold  united  with  a  quantity  of  the  anti- 
mony proportionable  to  the  quantity  of 
metals  which  have  been  separated  from 
the  gold,  and  which  are  now  united  with 
the  sulphur  of  the  antimony. 


As  a  single  fusion  is  not  generally  suf- 
ficient to  disengage  the  gold  from  all  its 
alloy,  it  ought  "to  be  fused  again  in  the 
same  manner,  and  with  the  same  quanti- 
ty of  sulphuret  of  antimony.  When 
these  first  fusions  have  been  well  made, 
the  gold  obtained  is  alloyed  with  antimo- 
ny only. 

It  is  then  to  be  put  into  a  large  cruci- 
ble, and  heated  sufficiently  to  keep  it  in 
good  fusion.  With  this  heat  the  antimo- 
ny will  be  dissipated  into  smoke,  and  the 
operation  must  be  performed  slowly,  but 
may  be  abridged  by  blowing  on  the  sur- 
face of  the  metallic  mass,  which  greatly 
assists  in  the  oxidation  and  evaporation 
of  all  bodies,  and  particularly  of  antimo- 
ny. The  purification  is  completed  by 
means  of  a  little  nitric  thrown  into  the 
crucible,  which  effectually  oxides  the  re- 
maining antimony.  Sometimes  the  gold 
is  deprived  of  its  usual  ductility,  which  is 
restored  by  fusing  it  with  nitre'and  borax. 

Purification  of  Silver,  by  nitre.  The 
silver  is  to  be  first  granulated,  and  then 
mixed  with  a  fourth  part  of  its  weight  of 
dry  nitre,  an  eighth  part  of  potash,  and  a 
little  common  glass,  all  in  powder.  This 
mixture  is  to  be  put  into  a  good  crucible, 
two-thirds  of  which  only  must  be  full. 
This  crucible  is  to  be  covered  with  a 
smaller  crucible  inverted  and  the  whole 
subjected  to  intense  heat.  Gases  which 
are  inflammable  escape  from  the  crucible, 
and  when  it  has  been  fully  burnt  it  is 
removed  and  broken.  The  silver  is 
found  in  a  button  at  the  bottom  covered 
with  ereen  alkaline  scoriae. 

PURPLE  OF  CASSIUS  is  best  made 
according  to  the  French  Pharmacopoeia, 
by  dissolving  10  parts  of  acid  chloride  of 
gold  in  2,000  parts  of  distilled  water ; 
preparing  in  another  vessel  a  solution  of 
10  parts  of  pure  tin  in  20  of  muriatic  acid, 
which  is  diluted  with  1,000  of  water,  and 
adding  this  by  degrees  to  the  gold  solu- 
tion as  long  as  a  precipitate  is  formed. 
The  precipitate  is  allowed  to  subside,  and 
is  to  be  washed  by  means  of  decantation : 
it  is  then  filtered  and  dried  at  a  very  gen- 
tle heat. 

PUTTY.  1.  A  kind  of  paste  or  cement 
|  compounded  of  whiting  or  soft  carbonate 
!  of  lime  and  linseed  oil,  beaten  or  kneaded 
i  to  the  consistence  of  dough.  In  this 
state  it  is  used  by  glaziers  for  fixing  in 
the  squares  of  glass  in  window  frames, 
&c,  and  also  by  house-painters  to  stop 
up  holes  and  cavities  in  wood-work  be- 
fore painting.  2.  A  powder  of  calcined 
tin,  used  in  polishing  glass  and  steel.  8. 
In  architecture,  a  very  fine  cement,  used 


pyr] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


507 


by  plasterers  and  stone  masons,  made  of 
lime  only. 

PUTREFACTION.  The  spontaneous 
decomposition  of  animal  and  vegetable 
substances,  attended  by  the  evolution  of 
fetid  gases.  By  this  process,  such  sub- 
stances are  reduced  either  to  their  origi- 
nal separate  elements,  or  to  much  more 
simple  compounds.  The  putrefaction,  or 
putrefactive  fermentation  of  animal  sub- 
stances, is  usually  attended  by  more  fetid 
and  noxious  exhalations  than  those  aris- 
ing from  vegetable  products,  arising 
chiefly  foom  the  more  abundant  presence 
of  nitrogen  in  the  former.  The  forma- 
tion of  ammonia,  or  of  ammoniacal  com- 
pounds, is  a  characteristic  of  most  cases 
of  animal  putrefaction,  while  other  com- 
binations of  hydrogen  are  also  formed, 
especially  carburretted  hydrogen,  toge- 
ther with  complicated  and  often  highly 
infectious  vapors  or  gases,  in  which  sul- 
phur and  phosphorus  arc  frequently  dis- 
cerned. These  putrefactive  effluvia  are 
for  the  most  part  easily  decomposed  or 
rendered  innocuous  by  the  agency  of 
chlorine :  hence  the  importance  of  that 
substance  as  a  powerful  and  rapidly  act- 
ting  disinfectant.  The  rapidity  of  putre- 
faction and  the  nature  of  its  products,  are 
to  a  great  extent  influenced  by  tempera- 
ture, moisture,  and  access  of  air.  A 
temperature  between  60°  and  80°,  a  due 
degree  of  humidity  and  free  access  of  air, 
are  the  circumstances  under  which  it 
proceeds  most  rapidly.  Hence  the  ab- 
straction of  the  air,  and  water,  or  humi- 
dity, or  its  fixation  by  cold,  by  salt,  sugar, 
spices,  &c,  will  counteract  the  process  of 
putrefaction.  {See  Fermentation,  De- 
composition.) 

PUZZOLANA,  or  PUZZUOLANA. 
A  loose  porous  volcanic  substance  or 
earth  of  a  gray  color,  deriving  its  name 
from  Puzzuoli,  in  Italy,  whence  it  was 
originally  brought.  It  is  found  in  many 
other  parts  of  Italy,  and  generally  in  the 
neighborhood  of  volcanoes  active  or  ex- 
tinct, from  whence  it  has  been  thrown 
out  in  the  form  of  ashes.  It  is  composed 
of  silicious,  argillaceous  and  calcareous 
earths,  and  iron.  When  mixed  with 
one-third  of  its  weight  of  lime  and  water 
it  immediately  hardens,  forming  an  ad- 
mirable water  cement. 

PYRITES.  The  sulphurets  of  cop- 
per and  iron,  commonly  distinguished 
as  copper  and  iron  pyrites.  The  former 
is  the  principal  ore  of  copper;  the  latter 
is  an  Abundant  natural  product  of  a  brass- 
yellow  color.  When  exposed  to  air  and 
moisture,   especially  after  having  been 


heated,  it  absorbs  oxygen,  and  yields 
sulphate  of  iron,  or  green  vitriol.  The 
term  is  derived  from  nvp,  fire  ;  either  be- 
cause they  sometimes  spontaneously  ig- 
nite, or  as  being  hard  enough  to  strike 
fire  with  steel. 

PYRO-ACETIC  SPIRIT.  This  liquid 
was  discovered  and  described  by  Chene- 
vix  long  before  pyroligneous  spirit  was 
known.  It  may  be  obtained  by  subject- 
ing to  dry  distillation  the  acetates  of  cop- 
per, lead,  alkalies,  and  earths  ;  the  liquor 
which  comes  over  then  should  be  set 
apart,  separated  by  decantation  from  the 
empyreumatic  oil,  and  distilled  a  second 
time  by  the  heat  of  a  water-bath.  The 
fine  light  fluid  which  now  comes  over 
first,  is  to  be  rectified  along  with  carbo- 
nate of  potassa,  or  chloride  of  calcium. 
As  pyro-acetic  spirit  usually  retains,  even 
after  repeated  distillations,  a  disagreeable 
empyreumatic  smell,  like  garlic,  a  little 
good  bone-black  should  be  employed  in 
its  final  rectification.  It  is  very  combus- 
tible, and  burns  with  a  brilliant  flame, 
without  smoke.  When  treated  by  chlo- 
rine, it  loses  an  atom  of  its  hydrogen,  and 
absorbs  2  atoms  of  chlorine.  It  is  soluble 
in  water,  alcohol,  ether,  and  is  not  con- 
vertible into  ether  by  strong  sulphuric 
acid.  It  is  used  for  dissolving  the  resins 
commonly  called  gums,  with  which  the 
bodies  of  hats  are  stiffened. 

PYROLIGNEOUS  ACID  has  been  no- 
ticed under  acetic  acid.  It  is  made  by 
the  distillation  of  wood  in  close  vessels. 
The  retorts  are  of  cast  iron,  6  feet  long, 
and  3  feet  8  inches  in  diameter.  Two  of 
these  cylinders  are  heated  by  one  fire, 
the  flame  of  which  plays  round  their  sides 
and  upper  surface  ;  but  the  bottom  is 
shielded  by  fire-tiles  from  the  direct  ac- 
tion of  the'  fire.  Two  cwts.  of  coals  are 
sufficient  to  complete  the  distillation  of 
one  charge  of  wood  ;  36  imperial  gallons 
of  crude  vinegar,  of  specific  gravity  1-025, 
being  obtained  from  each  retort.  The 
process  occupies  24  hours.  The  retort- 
mouth  is  then  removed,  and  the  ignited 
charcoal  is  raked  out  for  extinction  into 
an  iron  chest,  having  a  groove  round  its 
edges,  into  which  a  lid.  is  fitted. 

When  this  pyroligneous  acid  is  satu- 
rated with  quicklime,  and  distilled,  it 
yields  one  per  cent,  of  pyroxilic  spirit 
(sometimes  called  naphtha)  ;  which  is 
rectified  by  two  or  three  successive  dis- 
tillations with  quicklime. 

The  tarry  deposit  of  the  crude  pyrolig- 
neous acid,  being  subjected  to  distilla- 
tion by  itself,  affords  a  crude  pyro-acetic 
ether/which  may  also  be  purified  by  re- 


508 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PYR 


distillation  with  quicklime,  and  subse- 
quent agitation  with  water. 

The  pyrolignite  of  lime  is  made  by 
boiling  the  pyroligneous  acid  in  a  large 
copper,  which  has  a  sloping  spout  at  its 
lip,  by  which  the  tarry  scum  freely  flows 
over,  as  it  froths  up  with  the  heat.  The 
fluid  compound  thus  purified  is  syphoned 
off  into  another  copper,  and  mixed  with 
a  quantity  of  alum  equivalent  to  its 
strength,  in  order  to  form  the  red  liquor, 
or  acetate  of  alumina,  of  the  calico-prin- 
ter. The  acetate  of  lime,  and  sulphate  of 
alumina  and  potash,  mutually  decompose 
each  other ;  with  the  formation  of  sul- 
phate of  lime,  which  falls  immediately  to 
the  bottom. 

M.  Kestner,  of  Thann,  in  Alsace,  ob- 
tains, in  his  manufactory  of  pyroligneous 
acid,  5  hectolitres  (112  gallons  imperial, 
nearly)  from  a  cord  containing  93  cubic 
feet  of  wood.  The  acid  is  very  brown, 
much  loaded  with  tar,  and  marks  5° 
Baume  ;  220  kilogrammes  of  charcoal  are 
left  in  the  cylinders ;  500  litres  of  that 
brown  acid  produce,  after  several  distil- 
lations, 375  of  the  pyroligneous  acid  of 
commerce,  containing  7  per  cent,  of  acid, 
with  a  residuum  of  40  kilogrammes  of 
pitch.  For  the  purpose  of  making  a 
crude  acetate  of  lead  (pyrolignite)  he 
dries  pyrolignite  of  lime  upon  iron  plates, 
mixes  it  with  the  equivalent  decomposing 
quantity  of  sulphuric  acid,  previously  di- 
luted with  its  own  weight  of  water,  and 
cooled ;  and  transfers  the  mixture  as 
quickly  as  possible  into  a  cast-iron  cylin- 
ctric  still,  built  horizontally  in  a  furnace  ; 
the  under  half  of  the  mouth  of  the  cylin- 
der being  always  cast  with  a  semicircle  of 
iron.  The  acetic  acid  is  received  into 
large  salt-glazed  stone  bottles.  From 
100~ parts  of  acetate  of  lime,  he  obtains 
133  of  acetic  acid,  at  38°  Baume.  It  con- 
tains always  a  little  sulphurous  acid  from 
the  reaction  of  the  tar  and  the  sulphuric 
acid. 

Stoltze  has  ascertained,  by  numerous 
experiments,  that  one  pound  of  wood 
yields  from  6  to  7i  ounces  of  liquid  pro- 
ducts ;  but  in  acetic  acid  it  affords  a 
quantity  varying  from  2  to  5,  according 
to  the  nature  of  the  wood.  Hard  timber, 
which  has  grown  slowly  upon  a  dry  soil, 
gives  the  strongest  vinegar.  White  birch 
and  red  beech  afford  per  pound  7  J  ounces 
of  wood  vinegar,  1|  ounce  of  combustible 
oil,  and  4  ounces  of  charcoal.  One  ounce 
of  that  vinegar  saturates  110  grains  of 
carbonate  of  potassa.  Bed  pine  yields 
per  pound  6i  ounces  of  vinegar,  2\  ounces 
of  oil,   8$  ounces  of  charcoal ;  but  one 


ounce  of  the  vinegar  saturates  only  44 
grains  of  carbonate  of  potassa,  and  has 
therefore  only  two-fifths  of  the  strength 
of  the  vinegar  from  the  birch.  An  ounce 
of  the  vinegar  from  the  white  beech,  hol- 
ly oak  (Hex),  common  ash,  and  horse 
chestnut,  saturates  from  90  to  100  grains 
of  the  carbonate.  In  the  same  circum- 
stances, an  ounce  of  the  vinegar  of  the 
alder  and  white  pine  saturates  from  58  to 
60  grains. 

PYEOLIGNEOUS  or  PYEOX1LIC 
SPIEIT,  improperly  called  naphtha. 
This  is  employed,  as  well  as  pyro-acetic 
ether,  to  dissolve  the  sandarach,  mastic, 
and  other  resinous  substances,  which, 
under  the  name  of  gums,  are  used  for 
stiffening  the  bodies  of  hats.  It  is  de- 
scribed in  the  article  Pyroligneous  Acid, 
how  this  spirit  is  obtained.  Berzelius 
has  found  that  the  crude  spirit  may  be 
best  purified  by  agitating  it  wilh  a  fat  oil, 
in  order  to  abstract  the  empyreumatic 
oil ;  then  to  decant  the  spirit,  distil  it, 
first  with  fresh  calcined  charcoal,  and 
next  with  chloride  of  calcium.  The  py 
roligneous  spirit,  thus  purified,  is  color- 
less, and  limpid  like  alcohol  ;  has  an 
ethereous  smell,  somewhat  resembling 
that  of  ants.  Its  taste  is  hot,  and  analo- 
gous to  that  of  oil  of  peppermint.  Its 
specific  gravity,  given  by  Ure,  is 
0-824.  It  readily  takes  fire,  and  burns 
with  a  blue  flame,  without  smoke.  It 
combines  with  water  in  any  proportion  ; 
a  property  which  distinguishes  it  trom 
pyro-acetic  ether  and  spirit. 

PYEOLUS1TE.  A  mineralogical  term 
applied  by  some  to  the  common  black  or 
binoxide  of  manganese,  from  the  facility 
with  which  it  is  resolved  by  heat  into  ox- 
ygen and  a  suboxide. 

PYEOMETEB.  An  instrument  for  the 
measurment  of  temperatures  above  those 
which  we  are  able  to  estimate  by  the 
mercurial  thermometer. 

That  of  Daniel  has  superseded  that  of 
Wedgewood.  It  consists  of  a  bar  of 
platina,  and  a  tube  of  black  lead.  Its 
determinations  are  made  by  an  index, 
attached  to  the  platina  bar,  which  expands 
and  contracts,  and  the  index  traverses  a 
circular  scale  fixed  to  the  tube,  and  is  in- 
variable when  applied  to  the  same  objects. 
Wedgewood's  gives  the  same  indications 
at  a  low  heat  long  continued,  as  to  great 
heat  suddenly  brought  in  contact,  and 
therefore  fails. 

Guy  ton  de  Morveau  presented  to  the 
French  Institute  a  pyrometer  of  platina, 
which  measured  high  temperatures  by 
the  expansion  of  this  refractory  metal. 


pyr] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


509 


An  improvement  of  this  instrument  was 
brought  forward  by  Mr.  Daniel  in  1821, 
which  consisted  of  a  barofplatina  ten 
one-fifth  inches  long,  and  0*14  inch  in 
diameter.  It  is  placed  in  a  tube  of  black 
lead  or  earthen  ware,  and  the  difference 
between  the  expansion  of  the  platina  bar 
and  the  earthen  ware  tube  is  indicated  on 
a  circular  scale.  This  pyrometer  indicates 
a  change  of  about  7°  of  Fahrenheit  ;  or, 
in  other  words,  1°  of  Daniel  is  equal  to 
7°  of  Fahrenheit.  The  following  are 
some  of  the  results  obtained  by  this  in- 
strument. 


Fusing  Points  of  Metals,  derived  from  their  Expansions  to 
212°  and  662°,  supposed  equable. 


Daniel. 

Fahr. 

Boiling  point 

of  mercury.. 

92° 

644° 

Fusing 

point 

of  tin 

63 

441 

" 

bismuth  . . 

66 

462 

u 

M 

lead 

87 

609 

II 

U 

zinc 

94 

£48 

" 

u 

brass 

267 

1869 

M 

M 

silver 

319 

2233 

U 

* 

copper.... 
gold 

364 

2548 

" 

" 

370 

2590 

* 

" 

cast-iron  . . 

497 

3479 

Red  heat  just  visible  in  ) 
day-lisrlit \ 

140 

980 

Heat  of 

a  common  fire.... 

163 

1141 

From  212°  rate. 

From  662°  rate. 

Real  Temperature. 

Tin 

47  lo 

670 

848 

2159 

3262 

3096 

"690°? 

2049 

2366 

2489 

442°  by  Thermometer. 

612   by  Thermometer. 

773    by  Pyrometer. 
1873    by  Pyrometer. 

Silver 

1996   by  Pyron.cter. 

2785   by  Pyrometer. 

Mr.  Prinsep  has  framed  a  pyrometer 
which  determines  high  temperature  from 
the  fusing  point  of  different  metals,  and 
metallic  allovs. 

PYROPH'ORUS.  An  artificial  product, 
which  takes  fire  on  exposure  to  the  air. 
It  is  prepared  by  several  methods.  Four 
or  five  parts  of  "burnt  alum  are  mingled 
with  two  of  charcoal  powder.  The  mix- 
ture is  introduced  into  a  vial  or  matrass. 
The  vial  is  filled  two-thirds,  and  put  in- 
to a  crucible.  The  body  of  the  flask  is 
also  surrounded  with  sand,  after  which 
the  crucible  is  put  into  a  furnace,  and 
surrounded  with  red-hot  coals.  The  fire 
is  gradually  increased  until  the  flask  be- 
comes red-hot,  at  which  temperature  it 
is  maintained  for  about  a  quarter  of  an 
hour.  As  soon  as  the  vessel  is  cool 
enough  to  be  handled,  it  is  taken  out  of 
the  sand,  and  the  contents  transferred  in- 
to a  dry  glass,  made  warm,  which  must 
be  secured  with  a  glass  stopper.  When- 
ever this  mixture  "is  poured  out  in  the 
air,  it  takes  fire. 

A  pyrophorus  may  be  prepared  by  mix- 
ing three  parts  of  alum  with  one  of  wheat 
flour,  and  calcining  them  in  a  vial,  as  in 
the  above  case. 

Tartrate  of  lead,  also  on  being  heated 
in  a  glass  tube  until  it  becomes  converted 
into  coaly  matter,  gives  rise  to  a  beauti- 
ful pyrophorus. 

The  pyrophorus,  invented  by  Doctor 


Hare,  is  formed  from  heating  a  mixture 
of  three  parts  lampblack,  four  calcined 
alum  and  eight  peariashes,  in  a  gun-bar- 
rel. The  mixture  is  maintained  at  a 
cherry-red  heat  about  one  hour,  or  until 
it  ceases  to  give  off  inflammable  gas  at 
the  orifice  of  the  tube,  after  which  it  is 
withdrawn  from  the  furnace,  and  closely 
corked  from  the  air.  When  cold,  if  pour- 
ed from  the  gun-barrel  into  the  air,  it 
immediately  tdows  and  takes  fire :  and 
more  especially  if  breathed  upon,  or 
slightly  moistened.  This  pyrophorus 
may  be  preserved  in  its  full  activity  for 
a  year  or  more,  if  well  corked  up  from 
the  air. 

PYROTECHNY,  FIREWORKS.  The 
composition  of  luminous  devices  with 
explosive  combustibles,  is  a  modern  art, 
resulting  from  the  discovery  of  gunpow- 
der. 

The  three  prime  materials  of  this  art 
are,  nitre,  sulphur,  and  charcoal,  along 
with  filings  ot  iron,  steel,  copper,  zinc, 
and  resin,  camphor,  lycopodium,  &c. 
Gunpowder  is  used  either  in  grain,  half 
crushed,  or  finely  ground,  for  different 
purposes.  The  longer  the  iron  filings, 
the  brighter  red  and  white  sparks  they 
give ;  those  being  preferred  which  are 
made  with  a  very  coarse  file,  and  quite 
free  from  rust.  Steel  filings  and  cast-iron 
borings  contain  carbon,  and  afford  a  more 
brilliant  fire,  with  wavy  radiations.    Cop- 


510 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[PYR 


per  filings  give  a  greenish  tint  flame; 
those  of  zinc,  a  fine  blue  color ;  the  sul- 
phuret  of  antimony  gives  a  less  greenish 
blue  than  zinc,  but  with  much  smoke; 
amber  affords  a  yellow  fire,  as  well  as 
colophony,  and  common  salt ;  but  the 
last  must  be  very  dry.  Lampblack  pro- 
duces a  very  red  color  with  gunpowder, 
and  a  pink  with  nitre  in  excess.  It  serves 
for  making  golden  showers.  The  yellow 
sand  or  glistening  mica,  communicates 
to  fireworks  golden  radiations.  Verdi- 
gris imparts  a  pale  green ;  sulphate  of 
copper  and  sal-ammoniac,  a  palm-tree 
green.  Camphor  yields  a  very  white 
flame  and  aromatic  fumes,  which  mask 
the  bad  smell  of  other  substances.  Ben- 
zoine  and  storax  are  used  also  on  account 
of  their  agreeable  odor.  Lycopodium 
burns  with  a  rose  color  and  a  magnificent 
flame ;  but  it  is  principally  employed  in 
theatres  to  represent  lightning,  or  to 
charge  the  torcii  of  a  fury. 

Fireworks  are  divided  into  three 
classes:  1,  those  to  be  set  off  upon  the 
ground ;  2,  those  which  are  shot  up  in- 
to the  air ;  and  3,  those  which  act  upon 
or  under  water. 

Composition  for  jets  of  lire  ;  the  com- 
mon preparation  for  rockets  not  more 
than  |  of  an  inch  in  diameter,  is  :  gun- 
powder, 16  parts  ;  charcoal,  3  parts. 
For  those  of  larger  diameter;  gunpow- 
der, 16  ;  steel  filings,  4. 

Brilliant  revolving  wheel ;  for  a  tube 
less  than  f  of  an  inch  ;  gunpowder,  16  ; 
steel  filings,  3.  When  more  than  £  :  gun- 
powder, 16 ;  filings,  4. 

Chinese  or  Jasmine  fire;  when  less 
than  {  of  an  inch:  gunpowder,  16;  nitre, 
8 ;  charcoal  (fine),  3 ;  sulphur,  3  ;  pound- 
ed cast-iron  borings  (small),  10.  When 
wider  than  f  :  gunpowder,  16  ;  and  nitre, 
12;  charcoal,  3;  sulphur,  3 ;  coarse  bor- 
ings, 12. 

A  fixed  brilliant ;  less  than  |  in  diame- 
ter :  gunpowder,  16  ;  steel  filings,  4 ;  or, 
gunpowder,  16  ;  and  finely  pounded  bor- 
ings, 6. 

Fixed  suns  are  composed  of  a  certain 
number  of  jets  of  fire  distributed  circu- 
larly, like  the  spokes  of  a  wheel.  All 
the  fusees  take  fire  at  once  through  chan- 
nels charged  with  quick  matches.  Glories 
are  large  suns  with  several  rows  of  fusees. 
Fans  are  portions  of  a  sun,  being  sectors 
of  a  circle.  The  Patte  d?oie  is  a  fan  with 
only  three  jets. 

Cascades  imitate  sheets  or  jets  of  water. 
The  Chinese  fire  is  best  adapted  to  such 
decorations. 

Fixed  stars.    The  bottom  of  a  rocket  is 


to  be  stuffed  with  clay,  and  one  diameter 
in  height  of  the  first  preparation  being 
introduced,  the  vacant  space  is  to  be  filled 
with  the  following  composition,  and  the 
mouth  tied  up.    The  pasteboard  must  be 

Eierced  into  the  preparation,  with  five 
oles,  for  the   escape    of  the    luminous 
rays,  which  represent  a  star. 

Composition  of  fixed  stars :  — 

Ordinary.  Brighter.    Colored. 

Nitre 16  j2  0 

Sulphur 4  6  6 

Gunpowder  meal.     4  12  16 

Antimony 2  12 

Lances  are  long  rockets  of  small  diam- 
eter, made  with  cartridge  paper.  Those 
which  burn  quickest  should  be  the  long- 
est. They  are  charged  by  hand  without 
any  mould,  with  rods  of  different  lengths, 
and  are  not  strangled  at  the  mouth,  but 
merely  stuffed  with  a  quick  match  of 
tow.  These  lances  form  the  figures  of 
great  decorations  ;  they  are  fixed  with 
springs  upon  large  wooden  frameworks, 
representing  temples,  palaces,  pagodas, 
&c.  The  whole  are  placed  in  communica- 
tion by  conduits,  or  smal  paper  cartrid- 
ges, like  the  lances,  but  somewhat  coni- 
cal, that  they  may  fit  endwise  into  one 
another  to  any  extent  that  may  be  desir- 
ed. Each  is  furnished  with  a  match 
thread  fully  1£  inches  long,  at  its  two 
ends. 

Composition  for  the  white  lances:  nitre, 
16 ;  sulphur,  8 ;  gunpowder,  4  or  3.  For 
a  bluish-white :  nitre,  16 ;  sulphur,  8 ; 
antimony,  4.  For  blue  lances :  nitre,  16 ; 
antimony,  8.  For  yellow:  nitre,  16  ;  gun- 
powder/16 ;  sulphur,  8;  amber,  8.  For 
yellower  ones  :  nitre,  16  ;  gunpowder,  16 ; 
sulphur,  4 ;  colophony,  3 ;  amber,  4. 
For  greenish  ones  :  nitre,  16 ;  sulphur,  6 ; 
antimony,  6;  verdigris,  6.  F  or  pink  lan- 
ces :  nitre,  16 ;  gunpowder,  3  ;  lampblack, 
1. 

The  Bengal  flames  rival  the  light  of 
day.  They  consist  of,  nitre,  7  ;  sulphur. 
2  /antimony,  1.  This  mixture  is  pressed 
strongly  into  earthern  porringers,  with 
some  bits  of  quick  match  strewed  over 
the  surface.  These  flames  have  a  fine 
theatrical  effect  for  conflagrations. 

Bevolving  suns  are  wheels  upon  whose 
circumference  rockets  of  different  styles 
are  fixed,  and  which  communicate  by 
conduits,  so  that  one  is  lighted  up  in  suc- 
cession after  another.  The  composition 
of  their  common  fire  is,  for  sizes  below  f 
of  an  inch  :  gunpowder  meal,  16 ;  char- 
coal, not  too  fine,  8.  For  larger  sizes : 
gunpowder,  20 ;  charcoal,  not  too  fine,  4. 


>] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


511 


For  fiery  radiations :  gunpowder,  16  ; 
yellow  micaceous  sand,  2  or  3.  For 
mixed  radiations:  gunpowder,  1G;  pit- 
coal,  i  ;  yellow  sand,  1  or  2. 

The  waving  or  double  Catharine  wheels 
arc  two  suns  turning  about  the  same  axis 
in  opposite  directions.  The  fusees  are 
fixed  m  obliquely,  and  not  tangentially 
to  their  peripheries.  The  wheel  spokes 
are  charged  with  a  great  number  of  fu- 
sees ;  two  of  the  four  wings  revolve  in 
the  one  direction,  and  the  other  two  in 
the  opposite;  but  always  in  a  vertical 
plane. 

The  rockets  which  rise  into  the  air  with 
a  prodigious  velocity  are  among  the  most 
common,  but  not  least  interesting  fire- 
works. When  employed  profusely,  they 
form  those  rich  volleys  of  fire  which  are 
the  crowning  ornaments  of  a  public  fete. 
The  cartridge  is  similar  to  that  of  the 
other  jets,  except  in  regard  to  its  length, 
and  the  necessity  of  pasting  it  strongly, 
and  planing  it  well ;  but  it  is  charged  in 
a  different  manner.  As  the  sky-rockets 
must  fly  off  with  rapidity,  their  compo- 
sition should  be  such  as  to  kindle  instant- 
ly throughout  their  length,  and  extricate 
a  vast  volume  of  elastic  fluids.  To  effect 
this  purpose,  a  small  cylindric  space  is 
left  vacant  round  the  axis  ;  that  is,  the 
central  line  is  tubular.  The  com  portion 
of  sky-rockets  is  as  follows  : — 


When  the  bore  is 

3-4  of  an  inch  : 

Nitre 

16 

7 

Sulphur 

Brilliant  Fire. 

Nitre 

Charcoal 

Sulphur 

Fine  steel  filings 

Chinese  Fire. 
Nitre 

4 

16 
6 
4 
3 

16 

Charcoal 

Sulphur 

Fine  borings  of  cast-iron 

4 
3 
3  coarser 

The  cartridge  being  charged  as  above 
described,  the  pot  must  be  adjusted  to  it, 
with  the  garniture ;  that  is,  the  serpents, 
the  crackers,  the  stars,  the  showers  of 
fire,  &c.  The  pot  is  a  tube  of  pasteboard 
wider  than  the  body  of  the  rocket,  and 
about  one  third  of  its  length.  After  be- 
ing strangled  at  the  bottom  like  the 
mouth  of  a  vial,  it  is  attached  to  the  end 
of  the  fusee  by  means  of  twine  and  paste. 
These  are  afterwards  covered  with  paper. 
The  garniture  is  introduced  by  the  neck, 
and  a  paper  plug  is  laid  over  it.    The 


wholo  is  inclosed  within  a  tube  of  paste- 
board terminating  in  a  cone,  which  is 
firmly  pasted  to  the  pot.  The  quick- 
match  is  now  finally  inserted  into  the  soul 
of  the  rocket.  The  rod  attached  to  the 
end  of  the  sky-rockets  to  direct  their 
flight  is  made  of  willow  or  any  other 
light  wood. 

The  garnitures  of  the  sky-rocket  pots 
are  the  following  : — 

1.  Stars  are  small,  round,  or  cubic 
solids,  made  with  one  of  the  following 
compositions,  and  soaked  in  spirits. 
White  stars,  nitre,  16  ;  sulphur,  8  ;  gun- 
powder, 3.  Others  more  vivid  consist  of 
nitre,  16;  sulphur,  7;  gunpowder,  4. 

Stars  for  golden  showers,  nitre,  16;  sul- 
phur, 10;  charcoal,  4;  gunpowder,  16; 
lampblack,  2.  Others  yellower  are  made 
with  nitre,  16;  sulphur,  8;  charcoal,  2; 
lampblack,  2  ;  gunpowder,  8. 

The  serpents  are  small  fusees  made  with 
one  or  two  playing  cards  ;  their  bore  be- 
ing less  than  half  an  inch.  The  lardom 
are  a  little  larger,  and  have  three  cards  ; 
the  vetilles  are  smaller.  Their  composi- 
tion is,  nitre,  16 ;  charcoal,  not  too  fine, 
2  ;  gunpowder,  4 ;  sulphur,  4  ;  fine  steel 
filings,  6. 

The  cracker  is  a  round  or  square  box 
of  pasteboard,  filled  with  granulated  gun- 
powder, and  hooped  all  round  with 
twine. 

Roman  candles  are  fusees  which  throw 
out  very  bright  stars  in  succession.  With 
the  composition  (as  under)  imbued  with 
spirits  and  gun-water,  small  cylindric 
masses  are  made,  pierced  with  a*  hole  in 
their  centre.  These  bodies,  when  kin- 
dled and  projected  into  the  air,  form  the 
stars.  There  is  first  put  into  the  cartridge 
a  charge  of  fine  gunpowder  of  the  size 
of  the  star ;  above  this  charge  a  star  is 
placed  ;  then  a  charge  of  composition  for 
the  Roman  candles. 

Roman  candles,  nitre,  16;  charcoal,  6  ; 
sulphur,  3.  When  above  \  of  an  inch, 
nitre,  16;  charcoal,  8;  sulphur,  6. 

PHOSPHORITE,  Apatite.  Native 
Phosphate  of  lime,  natural  Rone-earth. 
Under  these  various  terms,  nearly  syno- 
nymous, are  comprehended  a  variety  of 
mineral  which  is  rather  sparingly  diffus- 
ed, and  has  lately  become  of  considerable 
value  in  an  agricultural  point  of  view,  as 
a  substitute  "for  bone-dust  and  guano, 
and  in  a  manufacturing  point  of  view,  as 
the  crude  material  from  which  phosphorus 
may  be  readily  obtained.  Apatite  is  a 
mineral  which  crystallizes  in  the  regular 
six-sided  prism  usually  terminated  by  a 
six-sided    truncated    pyramid ;     it    has 


512 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[PHO 


usually  a  yellowish  green  tint,  and  is 
translucent.*  In  hardness  it  ranks  above 
fluorspar,  and  below  feldspar.  It  is  a 
compound  of  phosphate  of  lime  with 
fluoride  of  calcium.  It  principally  oc- 
curs in  primitive  rocks,  and  is  found  in 
the  tin  mines  of  Cornwall,  England,  in 
those  of  Bohemia,  Moravia,  and  Saxony, 
and  from  the  rocks  of  St.  Gothard. 
Apatite  is  found  in  granitiform  rocks  in 
New  York,  New  England,  and  New  Jer- 
sey, in  isolated  crystalline  masses.  Its 
color  is  no  distinguishing  test,  as  it  as- 
sumes the  tint  of  "the  neighboring  rocks, 
being  thus  calculated  to  lead  to  decep- 
tion ks  to  its  nature  from  whence  it  has 
defived  its  name  {deceitful  Gr.)  Those  of 
a  bluish  or  green  color  may  easily  be  mis- 
taken for  beryls.  Some  are  colorless, 
violet,  or  lilac,  and  if  not  distinctly  crys- 
tallized may  be  mistaken  for  fluorspar. 
The  specific  gr.  of  the  crystals  of  apatite 
is  8*1,  They  are  soluble  in  nitric  acid, 
and  beome  phosphorescent  when  heated. 
Asparagus  stone  is  of  a  green-yellow 
color,  found  in  the  Tyrol,  where  the  crys- 
tals are  imbedded  in  talc.  Moroxite  is  a 
name  given  to  bluish-green  crystals  from 
Arndal,  Norway.  It"  is,  however,  un- 
common to  find  it  in  large  masses  as  well 
defined  crystals.  It  is  more  common 
in  the  fibrous  and  amorphous  condition. 
In  the  latter  state  it  is  known  as  phos- 
phorite. This  mineral  is  opaque,  of  a 
white  or  yellow-white  tint,  of  a  feathery 
structure,  with  numerous  small  cavities. 
This  variety  is  massive,  and  at  Lagrosso, 
in  Estremadura,  Spain,  forms  entire  hills  : 
it  is  there  used  as  u  building  stone.  In 
Hungary  phosphorite  occurs  of  a  loose 
earthy  texture  in  thin  beds.  In  this 
country,  besides  the  localities  of  crystal- 
line apatite,  there  are  two  locations  where 
phosphate  of  lime  occurs  in  abundance  ; 
one  of  these  is  near  Crown  Point,  on 
Lake  Champlain,  where  Dr.  Emmons 
discovered  it  in  situ.  He  has  described  it 
as  being  in  beds  of  almost  unlimited 
quantity,  and  of  a  great  degree  of  purity, 
yielding  as  much  as  93  per  cent  of  phos- 
phate of  lime  on  analysis;  the  gangue 
rock  is  serpentine,  which  communicates  a 
crrecn  tint  to  tlie  phosphorite  of  that 
focality.  The  other  point  where  phos- 
phorite is  found,  is  in  Morris  County, 
New  Jersey,  near  Pimple  Hill,  where  it 
has  been  found  as  a  vein,  or  dyke,  run- 
ning through  a  ferruginous  feldspathic 
rock,  which  here  tinges  the  phosphorite 
brownish  red.  This  vein  is  semi-crystalline 
in  some  spots,  and  of  considerable  purity. 
The  extent  of  this  vein  has  been  traced 


in  length  for  two  miles,  and  it  is  stated 
to  have  a  breadth  of  eight  feet :  five  feet 
below  the  surface,  it  widens  on  quarry- 
ing down.  These  are  among  the  largest 
beds  of  phosphorite  known,  and  are  of 
incalculable  value  either  for  art,  or  for 
agriculture. 

The  analysis  of  the  New  Jersey  bed 
of  phosphorite,  with  the  gangue  or  feld- 
spathic rock  by  which  it  was  surrounded, 
made  by  the  Editor,  yielded  the  follow- 
ing results  in  100  parts. 


|   1 

2 

3 

Phosphate  of  lime  - 

5-8 

2-6 

936 

Alumina  and  oxide  of 

iron     2*5 

1-0 



Lime       - 

09 

2-2 

36 

Magnesia    - 

-     03 

01 

0-2 

Chlorine  - 

-         PO 

0-7 

25 

Fluorine     - 

-     23 

traces 

Alkaline  salts 



•1 



Silica 

-|  87-2 

933 

— 

!ioo- 

100- 

loo- 

Specific gravity     - 

-    |    2-53 

2-31 

s' 

No  1,  was  a  mass  of  rhomboidal 
quartz  with  mica,  and  tinged  with  oxide 
of    chrome. 

No.  2,  was  the  feldspathic  gangue  stone 
in  the  immediate  vicinity. 

No.  3,  apatite  from  the  vein.  Thia 
sample,  heated  with  sulphuric  acid,  gave 
off  no  hydrofluoric  acid  vapors,  showing 
the  absence  of  fluorspar,  which  usually 
accompanies  phosphate  of  lime.  In  its 
place,  liowever,  was  substituted  chloride 
of  sodium,  giving  it  some  resemblance 
to  the  variety  described  by  H.  Rose  as 
clor-apatite.  The  mineral  found  in  New 
Jersey  is  very  brittle,  easily  pulverized, 
and  might  be  readily  ground  into  powder, 
and  made  marketable'  as  a  substitute  for 
bone-dust,  of  which  it  has  precisely  the 
mineral  composition.  Phosphorite,  as  a 
mineral,  is  generally  found  in  primary 
rocks,  and  in  conta'ct  with  serpentine. 
Phosphate  of  lime  has  however  been 
found  in  England  and  Europe  (continen- 
tal), in  other  situations,  as  in  beds  of  clay, 
of  the  upper,  secondary,  and  tertiary 
periods.  Captain  Ibbotson  has  found 
phosphate  of  lime  in  the  chloritic  marl  of 
the  Isle  of  Wight.  This  is  geologically 
the  upper  green  sand-bed  immediately 
under  the  chalk-marl.  In  the  lower  part 
of  the  green  sand-bed,  ammonites  and 
scaphites  occur  mixed  with  coprolitic 
masses,  rich  in  phosphate  of  lime  ;  the 
coprolites  are  now  understood  to  be  the 
fossil  excretions  of  the  Saurian  tribes. 
Mr.  Nesbitt  has  found  in  the  chalk-marls 
phosphate  of  lime  to  the  extent  of  two  or 


Qui] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


513 


three  percent.  Nodules  (coprolites),  from 
the  gault,  near  Maidstone,  England,  have 
furnished  twenty-eight  per  cent  of  phos- 
phate of  lime.  The  green  sand,  and 
upper  secondary  beds  of  this  country, 
have  not  been  examined  sufficiently  to 
determine  whether  it  exists  or  not.  Mr. 
Rogers,  in  his  geological  report  of  the 
State  of  New  Jersey,  looks  upon  the 
richness,  as  a  manure,  of  the  green  sand 
to  be  due  to  the  potash  present  in  it,  of 
which  substance,  in  some  cases,  he  ob- 
tained so  much  as  seventeen  per  cent. 
Other  analyses,  by  different  chemists, 
have  not  supported  this  large  amount  of 
alkali,  and  it  is  probable  that  some  of  its 
fertility  may  be  due  to  the  preseuce  of 
phosphate  of  lime. 

QUARRYING,  is  the  extracting  stones 
from  strata  lying  in  regular  layers,  and 
performed  by  the  pick,  wed^e,  lever,  or 
iron  crow,  and  hammer.  When  not  in 
layers,  or  in  rocks,  harder  than  sand- 
stone, recourse  is  had  to  blasting,  for 
which  Hancock's  fuses  are  a  very  suc- 
cessful modern  invention. 

QUARTATION.  In  metallurgy,  the 
separation  of  silver  from  gold  by  means 
of  nitric  acid.  To  extract  the  whole  of 
the  silver  from  gold  by  the  action  of  nitric 
acid,  it  is  necessary  that  there  should  be 
at  least  three  parts  of  silver  to  one  of 
gold,  otherwise  the  gold  protects  the 
silver  from  the  action  of  the  acid;  so 
that,  in  thus  separating  these  precious 
metals,  it  is  customary,  where  gold  great- 
ly predominates,  to  add.  silver  till  it  con- 
stitutes at  least  three  fourths  of  the  alloy. 
QUARTER.  The  fourth  part  of  any 
thing.  As  a  term  of  weight,  it  denotes 
the  fourth  of  a  hundred  weight,  or  28 
pounds;  as  a  dry  measure,  it  signifies 
the  fourth  of  a  chaldron. 

Quarter.  The  after  part  of  the  ship's 
side.  On  the  quarter,  implies  the  bearing 
or  position  of  an  object  seen  between  abaft 
and  abeam. 

QUARTZ.  The  name  given  by  min- 
eralogists to  numerous  varieties  of  rock 
crystals,  the  native  oxides  of  silicium, 
called  also  silicious  or  flint  earth,  and 
silicic  acid.  Quartz  is  most  comprehen- 
sive in  its  varieties.  It  occurs  both  crys- 
tallized and  massive,  and  in  both  states 
is  most  abundantly  diffused  throughout 
nature,  and  is  especially  one  of  the  con- 
stituents of  granite  and  the  older  rocks. 
It  generally  "occurs  in  hexagonal  prisms, 
terminated  by  hexagonal  pyramids.  It 
scratches  glass  readily,  gives  fire  with 
steel,  becomes  positively  electrical  by 
friction,  and  two  pieces  when  rubbed 
22* 


together  become  luminous  in  the  dark. 
The  colors  are  various,  as  white,  gray, 
reddish,  yellowish  or  brownish,  purple, 
blue,  green.  Horn  stone,  amethyst, 
siderite,  agate,  avanturine,  flint,  opal, 
chalcedony,  onyx,  sardonyx,  and  jasper 
are  varieties.     (See  Lapidary.  ) 

QUASSIA.  A  name  formed  in  remem- 
brance of  a  negro  named  Quassy,  who 
first  made  known  the  medicinal  virtues 
of  one  of  the  species.  A  genus  of  South 
American  tropical  plants,  consisting  of 
trees  ;  nat.  order  Simarubacae.  The  wood 
of  two  species  is  known  in  commerce  by 
the  name  of  Quassia  •  Q.  a/nara,  a  native 
of  Surinam ;  and  Q.  excelsa  (Picrcena 
excelsa,  Lindley),  a  native  of  Jamaica. 
Both  kinds  are  imported  in  billets,  and 
are  inodorous,  but  intensely  bitter,  espe- 
cially the  Jamaica  Quassia.  The  active 
principle  has  been  termed  cmassite,  a 
neutral  body  readily  soluble  in  alcohol. 
Quassia  is  a  pure  and  simple  bitter,  pos- 
sessing marked  tonic  properties,  and 
hence  useful  in  debility,  particularly  of 
the  stomach  and  muscular  system.  It  is 
generally  given  in  the  form  of  infusion. 
An  infusion  of  quassia  sweetened  with 
sugar  is  useful  to  destroy  flies.  The 
wood  of  Q.  excelsa  is  employed  by  fraud- 
ulent brewers  in  adulterating  beer,  as  a 
substitute  for  Hops. 

QUERCITRON.  1.  The  Quercus  nigra, 
black  oak,  or  dyer^s  oak,  which  grows  from 
Canada  to  Georgia,  and  west  to  the  Mis- 
sissippi. It  frequently  attains  the  height 
of  seventy  or  eighty  feet,  and  is  one  of 
the  largest  trees  of  the  American  forests. 
2.  The  bark  of  the  Quercus  nigra,  or 
American  oak ;  it  is  a  highly  valuable 
dye-stuff,  and  is  used  in  the  production 
of  some  of  the  most  durable  yellows.  It 
was  first  brought  before  the  public  by 
Dr.  Bancroft.  Although  this  oak  affords 
a  yellow  color,  yet  it  is  not  the  yellow  oak, 
that  name  being  commonly  applied  to 
Quercus  Castanm.     (See  Oak.) 

QUICKLIME.  Caustic  lime.  Lime- 
stone freshly  burnt,  and  deprived  by 
that  means  of  its  carbonic  acid.  See 
Limk.) 
QUICKSILVER.  (See  Mercury.) 
QUINIA,  or  QUININE.  An  alkaline 
base  obtained  from  yellow  bark ;  the 
Cinchona  cordifolia.  This  substance, 
combined  with'  sulphuric  acid,  forms  the 
sulpliate  of  quinia,  which  is  now  so  ex- 
tensively used  as  a  medicine,  and  as  a 
substitute  for  the  various  forms  of  Peru- 
vian bark.  To  obtain  quinia,  bruised 
yellow  bark  is  boiled  in  repeated  portions 
of  water,   acidulated  by  sulphuric  acid, 


514 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[rai 


till  all  its  soluble  matters  are  extracted  ;  a 
little  excess  of  quicklime  is  then  added  to 
the  strained  decoction,  and  the  precipi- 
tate which  is  formed  is  collected,  washed, 
and  carefully  dried ;  it  is  then  digested 
in  alcohol,  which  takes  up  the  quinia, 
and  from  which  it  may  be  obtained  in 
the  form  of  a  yellowish  uncrystallizable 
substance  by  careful  evaporation.  It  is 
dissolved  in  dilute  sulphuric  acid,  and 
the  sulphate  of  quinine  or  quinia,  crys- 
tallizes from  its  concentrated  solution  in 
fine  silky  prisms,  which  effloresce  on  ex- 
posure to  air.  Sulphate  of  quinia  is  diffi- 
cultly soluble  in  water,  and  intensely 
bitter.  It  is  more  strictly  a  disulphate  of 
quinia. 

Cinchona  exists  in  all  barks  to  some 
extent ;  and  there  are  several  modes  of 
separating  the  quinine  from  the  cinchona, 
viz: — 

1.  By  evaporating  the  alcoholic  solu- 
tion on  cooling,  the  cinchona  crystallizes, 
while  the  quinine  remains  dissolved. 

2.  Digestion  in  ether  dissolves  the 
quinine,  and  leaves  the  cinchona. 

3.  We  may  supersaturate  slightly  the 
two  bases  with  sulphuric  acid.  Now  as 
the  supersulphate  of  quinine  is  sparingly 
soluble,  the  liquor  need  only  to  be  evap- 
orated to  a  proper  point  to  crystallize  out 
that  salt,  while  the  supersulphate  of  cin- 
chona continues  in  solution  with  very 
little  of  the  other  salt.  Even  this  may  be 
separated  by  precipitating  the  bases,  and 
treating  them,  as  above  prescribed,  with 
alcohol  or  ether. 

One  pound  of  bark  rarely  yields  more 
than  two  drachms  of  the  bases.  One 
pound  of  red  bark  afforded,  to  Pelletier 
and  Caventou,  74  grains  of  cinchona, 
and  107  grains  of  quinine. 

Quinine  is  composed  of  75-76  carbon, 
7-52  hydrogen,  8-11  azote,  and  8-61  oxy- 
gen. 

The  salts  of  quinine  are  distinguished 
by  their  strong  taste  of  Peruvian  bark, 
and  if  crystallized,  by  their  pearly  lustre. 
Most  of  them  are  soluble  in  water,  and 
some  also  in  ether  and  alcohol.  The  sol- 
uble salts  are  precipitated  by  the  oxalic, 
gallic,  and  tartaric  acids,  and  by  the  salts 
of  these  acids.  Infusion  of  nutgalls  also 
precipitates  them. 

The  sulphate  of  quinine  is  the  only  ob- 
ject of  manufacturing  operations.  Upon 
the  brownish  viscid  mass  obtained  in  any 
of  the  above  processes  for  obtaining 
quinine,  pour  very  dilute  sulphuric  acid, 
in  sufficient  quantity  to  produce  satura- 
tion. The  solution  must  be  then  treated 
with  animal  charcoal,  filtered,  evaporated, 


allowed  to  cool,  when  it  deposits  crys- 
tals. 1000  parts  of  barks  afford,  upon 
an  average,  12  parts  of  sulphate.  The 
sulphate  of  cinchona,  which  is  formed 
at  the  same  time,  remains  dissolved  in 
the  mother-waters. 

EACEMIC  ACID.  An  acid  found, 
together  with  the  tartaric  acid,  in  the  tar- 
tar obtained  from  certain  vineyards  on 
the  Rhine.  It  is  the paratartaric  acid  of 
Berzelius.  It  is  less  soluble  in  water 
than  tartaric  acid,  and  differs  in  the  form 
of  its  crystals  and  in  its  salts  ;  yet  it  ap- 
pears to  be  isomeric,  and  to  have  the 
same  equivalent  with  the  tartaric  acid. 

RAILING.  A  fence  or  barrier  made 
of  posts  and  rails.  The  most  ordinary 
fence  of  this  description  in  the  country 
is  formed  of  wooden  posts  let  in  the  soil, 
so  as  to  stand  upright,  to  which  are 
nailed  or  mortised  horizontal  wooden 
rails,  one  above  another,  at  such  a  dis- 
tance as  to  prevent  domestic  animals 
from  penetrating  through  them.  In  some 
cases  one  horizontal  rail  is  fixed  to  the 
posts  near  the  ground,  and  another  near 
the  top  of  the  post,  and  the  interval  be- 
tween them  is  rendered  impervious  to 
cattle  by  upright  rails  nailed  to  the  top 
and  bottom  horizontal  rail.  Iron  railings 
are  generally  formed  in  this  manner. 

RAILROADS  or  RAILWAYS.  Roads 
constructed  of  tracks  of  iron  called  rails, 
on  which  the  wheels  of  carriages  roll, 
and  to  which  they  are  confined  by  ledges 
ox  jiang es  raised  either  on  the  rail  or  on 
the  tires  of  the  wheels. 

History  of  Railways.  About  the  mid- 
dle of  the  17th  century,  the  transport  of 
coals  from  the  pits  to  the  harbor  was  ef- 
fected in  the  coal  districts  of  Northum- 
berland and  Durham  by  laying  down  pa- 
rallel tracks  of  timber  with  a  horse-path 
between  them,  the  wheels  being  confined 
upon  the  beams  or  rails  of  timber  by 
ledges  or  flanges  projecting  from  the  in- 
side of  the  tire  of  the  wheels.  These 
timber  rails  were  constructed  in  pieces  of 
about  six  feet  long  with  a  section  of 
about  four  inches  square ;  they  were  sup- 
ported on  pieces  of  timber  called  sleepers 
laid  at  right  angles  to  them  transversely 
on  the  road.  These  sleepers  were  laid 
at  about  two  feet  apart,  so  that  each  pair 
of  parallel  rails  was  supported  by  three 
sleepers ;  besides  giving  support  to  the 
rails,  these  sleepers  also  had  the  effect  of 
maintaining  the  rails  in  gauge,  or  in  keep- 
ing them  at  a  fixed  distance  asunder. 
The  rails  were  fastened  to  the  sleepers  by 

Eins  driven  quite  through  the  rails,  and 
alf  way  through  the  sleepers ;  to  pre- 


AAl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


515 


serve  the  uniformity  of  the  upper  sur- 
face of  the  rail,  these  wooden  pins  were 
planed  off  at  the  top. 

The  necessity  of  giving  room  for  the 
flanges  of  the  wheels,  running  as  they 
did  below  the  surface  of  the  rail,  and  the 
small  depth  between  the  surface  of  the 
rail  and  the  sleeper,  rendered  it  impossi- 
ble to  protect  the  sleepers  effectually  from 
the  action  of  the  horses'  feet  by  any  co- 
vering of  gravel  or  other  material.  The 
sleepers  were  consequently  subject  to  be 
worn  and  destroyed.  The  rails,  also, 
being  worn  by  the  action  of  the  wheels 
still  more  rapidly  than  the  sleepers,  re- 
quired to  be  frequently  replaced ;  and, 
each  new  rail  being  pinned  down  to  the 
same  sleeper,  the  ends  of  the  sleepers 
were  gradually  perforated  by  so  many 
holes  that  the  sleepers  were  weakened, 
and  required  to  be  soon  replaced.  These 
defects  were  remedied  by  the  adoption 
of  the  double  timber  railway,  which  con- 
sisted In  laying  upon  the  surface  of  the 
timber  rails,  above  described,  additional 
rails  of  timber  of  equal  scantling,  at- 
tached to  the  lower  rails  by  wooden  pins, 
passing  quite  through  the  upper  and  half 
through  the  lower  rails,  in  the  same  man- 
ner as  the  lower  rails  themselves  were  at- 
tached to  the  transverse  sleepers.  This 
change  was  attended  with  many  advan- 
tages. Besides  the  increased  strength 
given  to  the  rails  by  the  double  timbers, 
the  depth  of  the  sleepers  below  the  up- 
per surface  of  the  superior  rail,  allowed 
the  sleepers  to  be  protected  from  the  ac- 
tion of  the  horses'  feet  by  covering  them 
with  broken  stones,  gravel,  or  other  road 
materials.  The  structure  of  rails  and 
sleepers  also  being  stronger  and  more 
weighty,  and  held  down  by  the  road  ma- 
terial with  which  the  sleepers  were  co- 
vered, allowed  a  packing  or  ballasting  to 
be  driven  under  the  rails,  so  as  to  give 
greater  stability  and  firmness  to  the  road. 
Another  advantage  obtained  by  this  ar- 
rangement was,  that  when  the  superior 
rails  were  worn  by  the  action  of  the 
wheels,  they  could  be  replaced  by  new 
ones  without  disturbing  the  inferior  rails  ; 
and  as  the  places  of  the  joints,  and  those 
at  which  they  were  attached  by  pins  to 
the  inferior  rails,  could  be  varied  at  plea- 
sure, the  pin-holes  made  in  the  inferior 
rails  would  not  come  in  the  same  place, 
or  near  each  other,  so  as  injuriously  to 
weaken  the  latter. 

The  next  improvement  consisted  in  the 
addition  of  a  plate  or  bar  of  iron,  about 
two  inches  broad  and  half  an  inch  thick,   j 
laid  aloug  the  upper  surface  of  the  supe-  j 


rior  rail,  and  attached  to  it  by  nails  or 
iron  pins  countersunk  in  it.  The  wheels 
of  the  carriages  ran  upon  this  iron  rail, 
which  formed  a  more  durable  surface 
than  that  of  the  wood.  In  our  country 
railways  of  this  construction  are  still  in 
very  general  use.  They  are  recommended 
by  the  abundance  and  cheapness  of  tim- 
ber, and  the  comparative  high  cost  of 
iron.  Such  a  roaa  is  tolerably  efficient 
where  the  traffic  is  light,  and  can  there- 
fore be  resorted  to  in  localities  and  cir- 
cumstances in  which  an  adequate  return 
could  not  be  obtained  for  the  capital  ne- 
cessary for  the  construction  of  these  tim- 
ber railways.  On  this  continent  many 
other  improvements  have  been  intro- 
duced, more  especially  in  the  substruc- 
ture of  the  road.  In  laying  out  the  road- 
way for  the  reception  of  the  rails,  two 
parallel  trenches  are  cut  along  the  line  of 
way  corresponding  to  the  distance  be- 
tween the  rails,  and  transverse  trenches 
at  right  angles  to  these  are  cut  to  receive 
the  sleepers  :  these  trenches  are  respec- 
tively bottomed  with  a  ballasting  of  bro- 
ken stone,  on  which  the  rails  and  cross- 
sleepers  rest.  This  basis  answers  the 
double  purpose  of  a  firm  and  durable 
support  for  the  road  and  an  effectual 
means  of  drainage.  The  scantling  of 
the  timbers  used  for  the  rails  is  usually 
six  inches  in  width  by  ten  inches  in 
depth  :  they  are  attached  to  the  sleepers, 
so  as  to  be  at  once  kept  from  springing 
from  them  and  from  altering  their  gauge, 
by  the  following  means  :  A  notch  is  cut 
in  the  sleeper  corresponding  to  the  size 
and  form  of  the  rail  ;  and  the  rail,  at  the 
place  where  it  is  let  into  the  sleeper,  is 
formed  with  a  vertical  surface  on  the 
outside,  and  a  levelled  surface  on  the 
inside,  increasing  in  width  downwards. 
When  let  into  the  notch  of  the  sleeper, 
the  levelled  part  of  the  rail  is  forced  into 
the  corresponding  cavity  of  the  notch  by  a 
wedge  driven  between  the  outside  edge  of 
the  rail  and  the  outer  surface  of  the  notch. 
Until  within  a  recent  period,  stone 
blocks  were  universally  regarded  as  the 
best  permanent  support  for  the  rails 
wherever  they  could  be  laid  upon  a  solid 
and  durable  foundation,  and  wooden 
sleepers  were  only  resorted  to  as  tempo- 
rary supports,  to  be  ultimately  super- 
seded by  stone  blocks  whenever  the 
foundation     of    the     road    should    be 

J>roperly  consolidated.  Opinion  has, 
lowever,  undergone  some  change  on 
this  subject,  and  wooden  sleepers  are 
now  always  used  in  preference  tc 
stone  blocks  for  permanent  purposes: 


510 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[rai 


whether  they  will  prove  economical,  when 
submitted  to  the  trial  of  a  long  period  of 
time,  experience  alone  can  decide. 

The  chairs,  which  are  the  immediate 
supports  or  props  on  which  the  rails 
rest,  are  attached  to  the  centre  of  the  up- 
per surfaces  of  the  blocks  in  the  follow- 
ing manner :  Two  holes  are  drilled  in  the 
blocks  to  a  sufficient  depth,  about  2 
inches  in  diameter,  into  wliich  plugs  of 
oak  or  other  hard  wood  are  driven ; 
holes  are  then  bored  in  these,  3-8ths  of 
an  inch  in  diameter,  corresponding  in 
position  with  two  holes  in  the  chair  of 
cast  iron,  which  is  to  support  the  rail. 
Iron  pins  of  half  an  inch  in  diameter  are 
then  driven  through  the  holes  in  the 
chairs  into  the  holes  in  the  block,  a  piece 
of  patent  felt  being  placed  between  the 
chair  and  the  block ;  and  the  chair  is 
thus  firmly  fastened  to  the  block. 

The  chairs  are  of  cast  or  wrought-iron, 
formed  with  a  cavity  corresponding  to 
the  magnitude  and  form  of  the  rail : 
they  vary  very  much  in  their  size  and 
form,  according  to  the  opinion  or  judg- 
ment of  the  engineer. 

A  great  variety  of  expedients  have 
been  resorted  to  to  maintain  the  rail  fixed 
in  its  position  in  the  chair.  Pins  and 
wedges  of  iron  were  first  used  of  various 
forms,  and  applied  in  various  ways. 
These,  however,  have  now  been  very 
generally  superseded  by  the  simple  con- 
trivance of  a  wooden  block  or  wedge, 
driven  in  between  the  side  of  the  chair. 
These  wedges  are  prepared  by  previous- 
ly passing  them  through  a  hydrostatic 
press,  so  as  to  harden  them  by  exposing 
them  to  a  severe  pressure.  Besides  af- 
fording a  very  effectual  fastening  to  the 
rail  in  the  chair,  these  wedges,  from  the 
nature  of  the  material,  soften  the  jar 
■which  attends  the  transition  of  the 
■wheels  over  the  chairs. 

The  distance  between  the  bearings  or 
chairs  has  also  been  subject  to  change. 
The  necessary  strength  or  weight  of  the 
rail  will  evidently  depend  on  this  dis- 
tance ;  the  greater  the  distance  between 
the  props,  the  greater  must  be  the 
strength  of  the  rail ;  and,  so  far  as  re- 
gards the  expense,  the  engineer  has  to 
balance  the  cost  of  heavier  rails  against 
the  saving  effected  by  a  diminished 
number  of  blocks  and  chairs.  But,  in- 
dependently of  the  consideration  of  ex- 
pense, the  effect  upon  the  carriages  and 
engines  is  to  be  considered.  Between 
chair  and  chair,  a  slight  flexure  of  the 
rail  takes  place,  and  the  wheels  have 
consequently  to  pass  over  a  series  of  emi- 


nences, so  as  to  give  to  the  carriages  a 
pitching  motion,  the  intervals  and  degree 
of  which  must  depend  conjointly  on  the 
strength  of  the  rails  and  the  distance 
between  the  chairs. 

The  least  distance  betweer?  the  chairs 
now  used  is  3  feet,  and  the  greatest  5 
feet ;  50  lb.  rails  are  very  generally  used 
on  3  feet  bearings  ;  65  lb.  rails  on  4  feet 
bearings  and  75  lb.  rails  on  5  feet  bearings. 

Kails  made  entirely  of  malleable  iron 
were  first  employed  at  the  collieries  near 
Edinburgh  ;  and  were  formed  of  rectan- 
gular bars,  which  presented  too  small  a 
surface  for  the  wheels,  or  otherwise  re- 
quire more  materials  than  it  would  be 
consistent  with  economy  to  employ.  To 
obviate  this  difficulty,  apatent  was  obtain- 
ed by  Birkenshaw,  of  Bedlington,  Eng., 
for  an  improved  form,  which  consists  in 
giving  the  bar  the  form  of  a  triangular 
prism.  The  chief  advantage  of  wrought 
iron  rails  is  the  reduction  of  the  number 
of  joints  and  the  difficulty  of  making 
cast-iron  rails  perfectly  even  at  the  joints. 
Edge  rails  are  best  adapted  for  permanent 
works,  and  they  are  of  such  a  nature 
that  ordinary  carriages  cannot  be  em- 
ployed upon  them  ;  but  on  any  railway 
where  such  carriages  can  be  used  they 
must  do  more  injury  to  the  surfaces  of  the 
rails  than  will  be  equivalent  to  the  advan- 
tage of  suffeiing  them  to  travel  on  them. 

Tram-ways  differ  from  the  preceding 
in  having  the  guiding  flanch  upon  the 
rails,  instead  ot  being  fixed  upon  the 
wheels  of  the  carriages.  It  affords  the 
advantage  of  employing  such  carriages 
as  can  be  used  wnere  there  are  no  rails. 
The  tram-rail  is  exceedingly  convenient 
for  temporary  uses,  and,  in  its  ordinary 
form,  it  is  much  used  in  quarries,  in 
mines,  in  forming  new  roads,  in  digging 
canals,  and  in  conveying  large  stones  for 
buildings,  and  other  purposes.  Tram- 
rails  are  very  weak,  considering  the 
quantity  of  iron  in  them,  and  in  some 
works  it  has  been  found  necessary  to 
strengthen  them,  by  adding  a  rib  on  the 
under  side. 

The  usual  length  of  a  one-tram  plate 
is  three  feet;  the  flanch  is  one  and  a 
half  inch  high  ;  the  sole,  or  bed,  three 
and  a  half  or  four  inches  broad,  and 
three-fourths  of  an  inch  thick  j  but  these 
dimensions  are  varied,  according  to  cir- 
cumstances :  the  most  approved  weight 
has  been  42  lbs.  for  each  plate.  The 
ends  from  which  the  plugs  project,  and 
on  which  the  tenons  and  notches  are 
made,  should  be  a  quarter  of  an  inch 
thicker  than  the  other  parts  of  the  plate. 


BAl] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


511 


By  this  method,  the  wheels  of  wagons 
cannot  be  obstructed  by  the  heads  of  the 
nails  rising  above  the  surface,  and  the 
blocks  are  not  disturbed  by  fixing  the 
plates. 

Turn-outs  are  made  by  means  of  a 
movable  or  switch-rail,  at  the  angle 
where  the  turn-out  track  branches  from 
the  main  one.  This  rail  is  two  or  three 
feet,  more  or  less,  in  length,  and  one 
end  may  be  moved  over  that  angle,  and 
laid  so  as  to  form  a  part  of  the  main 
track,  or  the  turn-out  track.  The 
switch-rail  is  usually  moved  by  the  hand, 
so  as  to  form  a  part  of  that  track  on 
which  the  wagon  is  to  move. 

The  principal  consideration,  in  regard 
to  the  carriages,  relates  to  their  bearings 
on  the  axle  and  the  rim  of  the  wheel. 
The  rale  given  by  Wood,  as  to  the  bear- 
ing on  the  axle,  is,  that,  in  order  to  pro- 
duce the  least  friction,  the  breadth  of  the 
bearing  should  be  equal  to  the  diameter 
of  the  axle  at  the  place  of  bearing.  This 
diameter  must  be  determined  by  the 
weight  to  be  carried  ;  and  the  breadth  of 
thebearing  will  accordingly  vary  with  it. 
The  objection  to  the  plate-rail  is,  that  the 
breadth  of  the  bearing  of  the  rim  of  the 
wheel  upon  such  a  rail  causes  an  unne- 
cessarily additional  friction  ;  and  the  re- 
sistance to  the  wheel  is  increased  in  con- 
sequence of  the  greater  liability  of  such 
a  rail  to  collect  dust  and  other  impedi- 
ments upon  its  surface.  The  edge-rail  is 
preferable  in  these  respects  ;  but,  at  first, 
these  rails  were  liable  to  one  difficulty, 
in  consequence  of  their  wearing  grooves 
in  the  rim  of  the  wheel,  so  that  the  fric- 
tion is  continually  increasing,  and  the 
wheel  so  becomes  unfit  for  use.  To 
remedy  this  defect,  the  rims  are  case- 
hardened,  or  chilled  by  rolling  them, 
when  hot,  against  a  cold  iron  cylinder. 
Wheels  so  case-hardened  are  found  to  be 
subject  to  very  little  wear. 

It  has  been  found,  in  practice,  that, 
for  the  ordinary  inclinations  of  railroads, 
SO  feet  per  mile,  the  wheels  may  be  so 
constructed  as  to  move  a  train  of  wagons 
by  their  mere  adhesion  to  the  rails.  The 
inclination  which  can  be  so  overcome 
must  evidently  depend  on  the  kind  of 
surfaces  of  the  rim  of  the  wheel  and  the 
rail,  the  weight  bearing  upon  the  wheels, 
the  weight  to  be  moved,  and  the  resist- 
ance from  the  friction  of  the  train  of 
wagons  ;  so  that  no  precise  rule  can  be 
given  that  shall  be  applicable  to  roads 
and  wheels  of  different  materials  and 
construction. 

Curves  on    Railways.  —  With   a  view 


to  insure  the  public  safety,  the  British 
legislature  has  generally  required  that  no 
curve  shall  be  allowed  upon  a  main  line 
with  a  less  radius  than  one  mile  :  the 
exceptions  to  this  are  where  one  railway 
passes  into  another  ;  and  at  the  termini, 
or  the  entrance  of  depots  or  stations.  In 
such  situations  the  trains  must  slacken 
their  speed,  and  therefore  a  sharp  curve 
is  attended  with  less  danger.  It  has  ap- 
peared, however,  that  these  restrictions 
upon  the  radii  of  curves  have  been  more 
stringent  than  safety  requires.  In  a 
course  of  experiments  made  by  Dr. 
Lardner,  it  has  been  established  that 
curves  of  a  mile  radius  produce  no  sen- 
sible increase  of  resistance  at  the  usual 
speed  of  railway  trains,  and  therefore 
curves  of  considerably  less  radius  may 
be  traversed  at  that  speed  without 
danger.  There  is  no  legislative  restric- 
tion on  the  subject  in  our  country,  where 
the  radius  of  the  curve  is  sometimes 
very  short. 

Resistance  of  Air  to  Railway  Trains. — 
Until  very  recently,  it  has  been  consid- 
ered by  engineers  that  the  resistance  to 
railway  trains  was  almost  entirely  due  to 
friction  and  mechanical  effects,  and  that 
that  part  of  the  resistance  which  de- 
pends on  the  atmosphere  formed  so  in- 
considerable a  portion  of  the  whole  that 
it  might  be  disregarded  in  practice.  The 
result  of  a  course  of  experiments,  made 
within  the  last  two  years,  by  Dr.  Lard- 
ner, have,  however,  indicated  a  serious 
amount  of  resistance  due  to  the  air.  If 
Dr.  Lardner's  conclusion  shall  be  further 
confirmed,  the  great  expense  attending 
the  maintenance  of  very  high  speed  on 
railways,  and  the  improbability  of  at- 
taining in  the  ordinary  work  of  a  line  the 
extraordinary  velocity  which  some  per- 
sons now  contemplate,  will  be  apparent. 

Of  the  Formation  and  Construction  of 
Railways. — WThatever    be    the    moving 

f)ower  to  be  used  for  the  transport  of 
oads  upon  a  railway,  its  force  must  be 
proportioned  to  the  average  resistance  of 
such  loads,  and  it  must  be  capable  of  va- 
rying its  energy  to  the  same  extent  as 
that  resistance  is  subject  to  variation. 
The  great  perfection  whieh  has  been  at- 
tained in  the  construction  of  the  rails, 
and  in  the  methods  of  fixing  them  in 
their  position  upon  the  road,  is  such  that 
the  resistance  offered  to  the  tractive  pow- 
er by  loads  moved  on  a  straight  and  level 
railway  may  be  regarded  as  practically 
uniform,  so  that  the  moving  power  by 
which  a  load  is  transported  at  a  given 
speed  on  a  straight  and  level  line  of  rail- 


518 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


|rai 


way  is  subject  to  a  resistance  as  unvaried  | 
and  as  uniform  as  any  to  which  moving 
powers  are  usually  submitted  in  any  of  I 
the  processes  of  art ;  but  as  the  amount 
of  resistance  to  the  tractive  powers  upon  \ 
a  straight  and  level  railway  is  diminished  j 
by  the  perfection  thus  attained  in   the  | 
construction  of  the  road,  so,  in  the  same  [ 
degree,  is  any  resistance  produced  by  a  ! 
departure  from  a  perfect  level  more  sen-  j 
sibly  felt.    Thus,  if  the  resistance  to  the  | 
moving  power  on  a  straight  and  level  I 
railway,   by    a  load  moved  at  a  given  | 
speed,  be  equal  to  the  250th  part  of  the 
load,  an  acclivity  which  would  rise  at 
the  rate  of  one  foot  in  250,  or  nearly  at 
the  rate  of  20  perpendicular  feet  in  a  mile, 
would  produce  a  resistance  to  the  mov- 
ing power  by  reason  of  the  ascent  alone, 
equal  to  a  250th  part  of  the  load,  and  there- 
fore equal  to  the  resistance  of  the  mov- 
ing power  would  sustain  on  a  level  line. 
It   follows,   therefore,  that  under  such 
circumstances,  in  drawing  a  load  up  such 
an  acclivity,  the   moving  power  would 
have  to  overcome  twice  the   resistance 
opposed  to  it  on  a  level;  for  the  same 
causes  which  produce  on  a  level  a  resist- 
ance amounting  to  the  250th  part  of  the 
load  equally  produce  this  resistance  in 
ascending  the  acclivity,    in   addition  to 
which  there  would  be  an  equal  amount 
of   resistance   due   to    the    ascent.      If, 
therefore,  under  such  circumstances,  the 
moving  power  were  required  to  draw  the 
load  up  the  acclivity  at  the  same  speed 
as  that  at  which  it  drew  it  on  the  level, 
the  machine  exerting  that  power  must 
be  endowed  with  properties  in  virtue  of 
which  it  is  capable  of  varying  its  energy, 
without  injury  to  its   structure,  in  the 
proportion  of  two  to  one. 

With  reference  to  horse  and  steam- 

Eower,  Anderson  observes,  that  a  wagon- 
orse  with  ease,  under  favorabU  drcum- 
stances,  draws  20  tons.  Fulton  says, 
that  five  tons  to  a  horse  is  the  average 
work  on  railways,  descending  at  the  rate 
of  three  miles  per  hour  ;  and  one  ton 
upwards  with  the  same  speed.  Telford 
observes,  that  on  a  railway  laid  with  a 
declivity  of  50  feet  in  a  mil*.,  one  horse 
will  readily  take  down  wagons  contain- 
ing 12  to  15  tons ;  and  bring  back  the 
same  wagons  with  four  tons.  Wilkes 
states,  that  a  horse  drew  down  the  de- 
clivity of  an  iron  road,  5  inches  in  16 
yards,  21  carriages  or  wagons,  laden  with 
coals  and  timber,  weighing  35  tons,  and 
the  same  horse,  up  this  declivity  drew 
5  tons  with  ease.  On  a  different  railway, 
one  horse  drew  21  wagons  of  five  cwt. 


each,  which,  with  their  loading  of  coals 
amounted  to  43  tons  8  cwt.,  down  the 
declivity  of  1  inch  in  three  yards  ;  and 
he  afterwards  drew  7  tons  up  the  same  ; 
the  hundred  weight  being  120  lbs. 

Sylvester  states  that  a  moving  force, 
which  will  give  the  velocity  of  5  miles 
an  hour,  or  22  feet  in  3  seconds,  will  be 
performed  down  a  plane,  1  inch  in  9 
yards,  or  1  in  324,  by  the  engine  making 
45  strokes  per  minute  (the  circumfer- 
ence of  the  wheel  being  nine  feet),  with 
a  pressure  of  9-7  lbs.  upon  an  inch  of 
each  of  the  two  cylinders,  the  area  of 
each  being  63-6  square  inches.  The 
weight  of  the  engine  and  16  wagons  is 
equal  to  154,560  lbs.,  nearly  70  tons. 

If  the  same  weight,  at  that  speed,  had 
to  move  on  a  dead  level,  and  acquired  the 
same  velocity  in  one  minute  as  before, 
the  moving  force  would  require  to  be 
1781  lbs.,  which  would  require  a  pressure 
of  13-7  lbs.  upon  one  inch.  But  after 
the  speed  is  obtained,  it  will  require  only 
7  lbs.  to  keep  it  moving  at  the  same  rate. 

If  the  same  load  were  required  to 
move  up  the  plane,  it  would  require  a 
moving  force  of  2328  lbs.,  or  a  pressure 
upon  every  square  inch  of  18-3  lbs.  And 
this  velocity  would  be  kept  up  by  a  con- 
stant pressure  of  1447  lbs.,  which  will  be 
11*2  lbs.  upon  every  inch  of  the  piston. 

When  the  engine  is  required  to  travel 
at  the  rate  of  nine  miles  per  hour,  the 
force  necessary  to  overcome  the  weight 
154,560  lbs.  will  be  for  the  first  minute, 
when  the  engine  is  travelling  on  a  level. 
2890"S1  lbs.;  when  moving  down  the  plane 
2461*61  lbs. ;  and,  when  moving  up  the 
plane  3320-01  lbs.  But  that,  when  the 
velocity  is  attained,  a  force  that  will 
balance  the  friction  is  sufficient  to  keep 
up  the  required  velocity.  This  force  is, 
for  travelling  on  a  level,  900  lbs. ;  for 
moving  down  the  plane,  471  lbs. ;  and 
for  moving  up  the  plane  1329  lbs. 

A  boat  weighing  with  its  load  15  tons, 
and  a  wagon  of  the  same  weight,  the  one 
on  a  canal  and  the  other  on  a  railway, 
would  be  impelled  at  the  following  rates, 
by  the  following  quantities  of  power — in 
pounds  and  in  horse-power — reckoning 
one  horse  equal  to  180  lbs. 

Canal. 


Mill  r  p«r  hour. 

In  pounds. 

Horse  power. 

2 

33 

02 

4 

133 

0-66 

6 

300 

175 

8 

533 

3- 

12 

1200 

7- 

16 

2133 

12- 

20 

3325 

18- 

RAl] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


51C 


Railway. 


In  pounds. 

Horse  power. 

100 

05 

102 

05 

105 

0-5 

109 

05 

120 

06G 

137 

075 

158 

1- 

The  force  required  to  keep  a  given 
weight  in  motion  does  not  vary  with  the 
velocity  :  thus,  a  force  of  14  lbe.  was 
found  to  overcome  friction,  and  keep  in 
motion  an  empty  coal-wagon,  weighing 
23-25  cwt.  on  a  railroad  ;  but  that,  on 
doubling  the  velocity,  no  more  force  was 
required.  Further,'  on  increasing  the 
weight,  or  load,  the  power  required  to 
overcome  the  friction,  and  keep  the 
wagon  in  motion,  did  not  increase  in 
similar  proportion,  but  up  to  76*25  cwt. 
was  about  l-14th  less. 

The  following  is  a  summary  of  railway 
communication  in  Europe  : — 

From  an  analysis  of  railroads  in  Great 
Britain  and  Ireland,  it  appears  that  the 
number  of  miles  of  railroad  open  for  use, 
on  the  30th  of  June,  1850,  was  5,447. 
The  number  of  passengers  conveyed 
during  the  preceding  half  year  was 
28,761,695.  The  number  of  persons  killed 
on  the  railroads  during  that  period  was 
86,  and  of  persons  injured  75.  Of  the 
persons  killed,  12  were  passengers,  five 
of  whom  were  killed  from  causes  beyond 
their  own  control,  and  seven  in  conse- 
quence of  their  own  misconduct  or  want 
of  caution.  Of  the  other  persons  killed, 
51  were  persons  in  the  employ  of  the 
railway  companies  or  of  contractors,  and 
21  were  trespassers  or  persons  in  no  way 
connected  with  the  railroads,  who  lost 
their  lives  in  consequence  of  improperly 
crossing  or  standing  on  the  tracks. 

Next'to  Great  Britain,  France  is  the 
nation  which  has  the  most  extensive  line 
of  railways.  Of  these,  the  chief  are  the 
St.  Etienne  Andrezieux,  the  Eoane  and 
Andrezieux,  Lyons  and  St.  Etienne, 
Paris  and  Versailles,  the  Epinac,  Paris 
and  Havre,  Paris  and  Lyons,  Paris  and 
Strasburg,  Calais  and  Paris,  the  Orleans, 
&c,  &c. 

Germany    beoran    to    experience    the 
luxury  and  benefit  of  fast  and  comfort- ble 
riding  in  the  year  1848,  by  constructing 
a  railroad,  of  which  eighty  miles  (more  j 
than  360  English  miles)  were  completed  i 
in  that  year.     At  the  beginning  of  1850,  \ 
there  had  been  added  840  German  miles 


more  to  the  length,  so  that  there  were 
then  more  than" four  thousand  English 
miles  of  railroad  opened  for  passengers 
in  that  country.  Add  to  tnese  both 
tracks  of  the  Maine  Wcser  line,  from 
Cassel  to  Frankfort,  we  have  nearly  fifty 
English  miles  farther.  Of  the  aggregate, 
over  fifteen  hundred  miles  belong  to  the 
different  governments. 

Prussia  owns  an  extent  of  340  Ger- 
man miles,  or  2,025  United  States  miles  ; 
Austria,  187  ;  Bavaria,  82i  ;  Saxony,  55i; 
Hanover,  48 ;  Baden,  52  ;  Electorate  of 
Hesse,  33  ;  Wurtemburg,  25 ;  Mechlen- 
burg  Schwerin,  19;  Anhalt,  12;  Bruns- 
wick, 1H;  Saxe  Weimar,  10.  In  Austria 
there  are  700  miles  of  railwav,  and  248 
miles  being  constructed.  All  the  remain- 
ing States  of  Germany  have  about  1,148 
miles. 

The  Wurtemburg  railroads,  and  the 
Budweiz-Linz-Gmunder  horse  line,  are 
quite  isolated.  The  upper  Rhenish  rail- 
road system,  which  comprehends  the 
Baden  government  line,  the  Maine  Neckar 
line,  the  Palatinate  Ludwig's  line,  the 
Taunus  line,  and  the  lines  from  Frank- 
fort to  Offenbach,  Hanau,  and  Friedbnrg, 
is  separated  from  the  large  North  Ger- 
man system  of  roads  by  the  unbuilt  por- 
tion between  Friedburg  and  Marburg,  as 
the  Bavarian  lines  are  separated  by  the 
tract  from  Plauen  to  Reichenbach,*  and 
the  Austrian  southern  line  by  the  tract 
from  Glognitz  to  Muertzenschlag,  (over 
the  Sommering.)  Forty  one  joint  stock 
companies  own  the  private  lines,  and 
their  funds  amount  to  one  hundred  and 
fifty-eight  and  a  half  million  thalers.  To 
this  other  loans  should  be  added,  of  sixty- 
two  and  a  half  millions. 

Major  Brown,  our  countryman,  thx 
consulting:  railroad  engineer  of  the  Em- 
peror of  Russia,  states  in  a  letter,  that  the 
Emperor  has  determined,  as  soon  as  the 
season  will  allow,  to  commence  the  pro- 
jected railroad  from  St.  Petersburgh  to 
Warsaw,  the  surveys  for  which  were 
made  in  1848.     Major  Brown  will,  by  his 

Position,  have  the  chief  superintendence, 
he  distance  in  this  instance  to  run  is 
from  750  to  800  of  our  miles,  and  stretch- 
ing, for  the  most  part,  through  an  inhos- 
pitable tract  of  country,  intersected  by 
many  rivers,  broad  morasses,  and  low- 
lands. 

The  railroad  from  St.  Petersburgh  to 
Moscow,  of  which  our  talented  country- 
man, Major  Whistler,  was  chief  engineer 
when  he  died,  is  now  nearly  finished.  It 
is  421  miles  long. 

In  1830  there  were  only  thirty  miles  of 


520 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


locomotive  railway  in  the  world,  now 
there  are  no  less  than  18,000  miles.  Ame- 
rica has  no  less  than  8,680  miles,  and 
will  soon  have  10,000  in  operation.  Mas- 
sachusetts alone  has  more  than  1,000, 
and  Pennsylvania  1,200.  In  1836  there 
were  only  15  miles  of  railroad  in  the 
State  of  New  York,  now  there  are  about 
2,283. 

The  entire  amount  of  capital  invested 
in  railway  communications  in  all  the 
countries  of  the  world,  is  estimated  at 
three  hundred  and  sixty-eight  millions 
and  a  half.  Upwards  of  18,656  miles  of 
railway  have  been  constructed.  The  cap- 
ital to  be  invested  in  7,800  miles  in  pro- 
gross,  will  amount  to  nearly  $147,000,000. 

The  total  extent  would  then  be  26,450, 
miles,  which  is  more  than  would  sur- 
round the  globe.  So  great  is  the  amount 
of  railway  mileage  in  Great  Britain,  that  it 
is  calculated  27  out  of  every  hundred  miles 
in  the  world  are  in  the  British  isles. 
Among  the  projected  lines  of  the  U.S.  are 
two  stupendous  lines,  one  from  Cincinnati 
to  St  Louis,  to  cost  $5,000,000;  and  sm- 
other from  Lake  Michigan  or  the  Mis- 
sissippi to  the  Pacific  Ocean,  to  cost  over 
$60,000,000,  for  a  distance  of  more  than 
2,000  miles.  Besides  these,  Ohio,  Penn- 
sylvania, Indiana,  Illinois,  and,  indeed, 
almost  every  State  has  various  routes 
surveyed  and  in  contemplation. 

The  Erie  Koad  is  the  longest  in  the 
world — 467  miles.  That  between  Mos- 
cow and  St.  Petersburg,  in  Russia,  is  next 
in  length,  being  420  miles.  The  Russian 
government  is  about  beginning  a  road 
from  Warsaw  to  St.  Petersburgh,  a  dis- 
tance of  more  than  700  miles,  of  which 
T.  S.  Brown,  (already  alluded  to,)  will 
be  chief  engineer.  It  is  noteworthy  that 
the  American  great  enterprise  is  by  a 
private  company;  the  Russian  is  built" by 
Government. 

The  first  charter  for  a  railroad  in  this 
country  was  granted  by  New  Jersey. 
The  Legislature,  at  the  session  of  1814- 
15,  chartered  the  New  Jersey  Railroad 
Company,  to  build  a  road  four  rods  wide 
from  the  river  Delaware,  near  Trenton, 
to  the  River  Raritan,  near  New  Bruns- 
wick. The  country  was  not  then  pre- 
pared for  the  enterprise,  and  the  work 
was  abandoned.  The  honor  of  introduc- 
ing railroads  was  reserved  for  Massachu- 
setts, and  the  first  road  that  was  built  on 
this  continent,  was  the  Quincy  Railroad, 
from  the  quarry  to  Neponset  river,  which 
was  first  used  in  the  year  1827. 

At  the  close  of  the  year  1848,  there 
were  1,614  miles  of  railroad  in  operation 


in  New  York,  and  on  the  1st  of  Decem- 
ber, 1849,  there  were  2,133,  showing  an 
increase,  in  eleven  months,  of  510  miles. 
By  the  1st  of  January,  1850,  there  were 
about  150  miles  more  in  operation,  which 
will  make  the  aggregate  length  2,283 
miles,  and  the  total  increase  669  miles. 
In  the  State  of  New  York  there  has  been 
an  increase  of  about  400  miles.  In  the 
Southern  and  Western  States,  a  great 
many  miles  of  railroad  have  been  opened 
this  year.  The  total  number  of  miles  of 
railroad  put  in  operation  in  the  United 
States,  during  the  year  1849,  was  not  much 
less  than  2,000.  At  the  close  of  the  year 
1848,  it  was  estimated  that  there  were 
6,120  miles  of  railroad  in  the  United 
States ;  to  which  add  the  2,000  opened, 
and  the  aggregate  at  the  close  ol  1849, 
would  have  been  8,120  miles. 

New  York  and  Erie  Railroad. — The 
line  is  now  open  to  Dunkirk.  The  whole 
cost  ot  equipments,  buildings,  &c,  is 
about  twenty  and  a  half  millions  of  dol- 
lars, and  the  cost  about  $38,706  per  mile 
— not  counting  the  machinery  and  build- 
ings. This  is  an  enormous  sum,  but  the 
expense  of  construction  is  very  moderate, 
considering  the  difficulties  of  the  work, 
and  the  manner  in  which  it  has  been  per- 
formed. The  earnings  for  the  year  1850 
have  been  $1,600,300,  or  $5,000  per  mile  ; 
in  1849  they  were  only  $3,697  per  mile. 
This  is  a  great  increase,  but  nothing  to 
what  may  be  expected  now  that  the  road 
is  finished.  This  road  runs  through 
some  of  the  grandest  mountain  scenery 
in  our  country.  The  bridges,  cuttings, 
and  gradings  are  works  of  great  magni- 
tude. The  most  able  engineers  and 
architects  have  been  employed  by  the 
comj>any.  This  road  is  of  a  wider  track 
than  the  common  roads  in  our  country. 
It  is  now  an  unbroken  line  of  wide  track 
543  miles  long,  and  at  the  rate  of  30  miles 
per  hour,  a  traveller  will  be  able  to  reach 
Erie  from  New  York  in  18  hours. 

The  State  of  Georgia  has  been  much 
improved  by  the  lines  which  traverse  it. 
By  the  Central  Railroad  of  191  miles,  and 
the  Macon  and  Western  of  101  miles,  she 
has  a  direct  communication  with  Atlanta, 
distant,  in  all,  292  lniles^  through  the 
heart  of  the  State,  embracing  its  richest 
regions,  which  field  is  widened  by  the 
cross  lines  of  the  Southwestern  and  the 
Macon  and  Columbus  roads,  stretching 
to  different  points  of  the  valley  of  the 
Chattahoochie  and  the  borders  of  Ala- 
bama; and  the  intended  extensions, 
northward  from  Atlanta,  of  the  main 
central  route  to  Nashville  on   the  one 


BAI] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


521 


side,  and  to  Knoxville  on  the  other,  will 
open  to  her  the  vast  and  as  yet  undevel- 
oped wealth  of  Tennessee. 

In  Indiana,  1,205  miles  of  railroad  have 


been  projected,  and  212  have  been  com- 
pleted. 

•   The  following  is  a  summary  of  the  prin- 
cipal lines  of  railroad  in  the  United  States : 


Bangor  and  Piscataquis 

Atlantic  ami  St.  Lawrence 

Kennebec,  Bath,  and  Portland 

Androscoggin  and  Kennebec 

Portsmouth  and  Concord 

Concord  and  Montreal 

Nash  tia  and  Concord 

Cheshire 

Sulli  v;i  n 

Connecticut  and  Passumsic 

Vermont  Central 

Rutland 

Fitchburg 

Vermont  and  Massachusetts 

Boston  and  Maine 

Eastern 

Peterborough  and  Shirley 

Fitchburg  and  Worcester 

Lowell  and  Lawrence 

Norfolk  County 

Nashua  and  Lowell 

New  Bedford  and  Taunton 

Old  Colony 

Fall  River 

Boston,  Providence,  and  Stonington. 

Boston,  Worcester,  and  Western 

Providence  and  Worcester 

Connecticut  River 

Worcester  and  Norwich 

N.  Haven,  Hartford,  and  Springfield 

Canal 

Naugatuc 

New  London  and  Willimantic 

New  Haven  and  New-York 

Housatonic 

Long  Isla nd 

Hudson  River 

Western 

New- York  and  Erie 

Buffalo  and  Niagara 

Oswego  and  Syracuse 

Saratoga  and  Schenectady 

Cayuga  and  Susquehanna 

New  Jersey, Trenton,  and  Philadel. . 

Camden  and  South  Amboy 

Philadelphia  and  Reading 

Philadelphia  and  Columbia 

Harrisburs  and  Chambersburg 

Philadelphia  and  Baltimore 

Baltimore  and  Susquehannah 

Baltimore  and  Ohio 

Baltimore  and  Washington 

Richmond  and  Potomac 

Richmond  and  Petersburg 

Petersburg 

Wilmington  and  Weldon 

South  Carolina 

Georgia 

Western  and  Atlantic 

Central 

Montgomery  and  West  Point 

Tuscumbia  and  Decatur 

Vicksburg  

Lexington  and  Ohio 

Mad  River  and  Erie , 

Little  Miami 


States. 


Maine 

Do 

Do 

Do 

New  Hampshire 

Do. 

Do. 

Mass.,  N.  II 

Vermont    

Do 

Do 

Do 

Massachusetts  . . 
Vermont,  Mass.. 
Mass.,  N.  II.,  M. 
Do.        do.     do. 

Mass.,  N.H 

Massachusetts  . . 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Mass.,  R.  I.,  Ct. 
Mass.  and  N.  Y. 
Mass.  and  R.  I. 
Mass.  and  Vt. . . . 
Mass.  and  Ct.... 

Do.  do 

Connecticut .... 

Do 

Ct.  and  Mass.... 
Ct.andN.  Y.... 
Ct.  and  Mass.... 

New- York 

Do 

Do 

Do 

Do 

Do 

Do 

Do 

N.  .Land  Pa.... 

Do 

Pennsylvania  .. 

Do 

Do 

Pa.,  Del.,  Md.  .. 
Md.  and  Penn... 

Md.  and  Va 

Md.  and  D.  ofC. 

Virginia 

Do 

Va.  and  N.  Car. 
N.  Carolina  .... 
S.   Carolina.... 

Georgia 

Do 

Do 

Ala.  and  Geo 

Do.  do 

Mississippi   

Kentucky 

Ohio...; 

,  Do 


Places  connected. 


Bangor  and  Oldtown 

Portland  and  Canada  Line 

Portland  and  Augusta 

Augusta  and  Lewiston  Falls 

Portsmouth  and  Concord 

Concord  and  Montreal  Railroad 

Nashua  and  Concord 

S.  Ashburnham  and  Bellows  Falls  .. 

Bellows  Falls  and  Hartford,  Vt 

Hartford  and  Derby,  Canada  Line  .. 

Hartford  and  Burlington 

Bellows  Falls  and  Rutland 

Boston  and  Fitchburg 

Fitchburg  and  Brattleborough 

Boston  and  Portland 

Boston  and  Portland 

Groton  and  Peterborough 

Fitchburg  and  Worcester 

Lowell  and  Lawrence 

Boston  and  Prov.  R.  R.  &  Blackstone 

Nashua  and  Lowell 

New  Bedford  and  Taunton 

Boston  and  Plymouth 

Boston  and  Fall  River 

Boston,  Providence,  and  Stonington. 

Boston  and  Albany 

Providence  and  Worcester 

Springfield  and  Brattleborough 

Worcester  and  Norwich 

New  Haven,  Hartford,  &  Springfield 

New  Haven  and  W.  Springfield 

Bridgeport  and  Winsted 

New  London  and  Palmer,  Mass 

New  Haven  and  New  York 

Bridgeport  and  West  Stockbridge 

Brooklyn  andGreenport 

New- York  and  Albany 

Albany  and  Buffalo 

Piermont  and  Dunkirk 

Buffalo  and  Niagara  Falls 

Oswego  and  Syracuse 

Saratoga  and  Schenectady 

Ithaca  "and  Owego 

Jersey  City  and'Philadelphia 

Camden  and  South  Amboy 

Philadelphia  and  Reading 

Philadelphia  and  Columbia 

Harrisburg  and  Chambersburg 

Philadelphia  and  Baltimore 

Baltimore  and  Columbia 

Baltimore  and  Cumberland 

Baltimore  and  Washington 

Acquia  Creek  and  Richmond 

Richmond  and  Petersburg 

Petersburg  and  Weldon 

Wilmington  and  Weldon 

Charleston  and  Hamburg 

'Augusta  and  Atlanta 

JAtlanti  and  Dalton 

Savannah  and  Macon 

Montgomery  and  West  Point 

Tuscumbiaand  Decatur 

Vicksburg  and  Clinton 

Lexington  and  Frnnkfor 

S-indusky  and  Springfield 

Springfield  and  Cincinnati 


Length. 


522 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[rai 


Names. 

States. 

Placps  connected. 

Length. 

Do 

56 
86 

Madison  and  Indianapolis 

Indiana 

Madison  and  Indianapolis "" 

25 
70 
146 
33 

Do 

Michigan  Centra) 

Do 

Mich,  and   Ohio 
New- York 

Vermont 

New-York  and   Albany,   as    far    as 
Poughkepsie  completed 

Rutland  and  Burlinston 

120 

It  is  calculated  that  at  the  end  of  1851, 
there  will  be  10,600  miles  of  railroads  in 
operation  in  our  country ;  and  with  those 
which  have  already  been  contracted  for, 
there  will  be  2,000  miles  more  construct- 
ed in  1852.  No  country  in  the  world  can 
equal  ours  for  the  number  of  railroads. 

Besides  the  lines  in  this  country,  other 
lines  are  in  contemplation ;  such"  as  the 
Canadian  line  connecting  Halifax  with 
Montreal  and  the  Isthmus. 

The  Panama  Railroad.  The  Panama 
Railroad  progresses  very  slowly,  but  it  is 
said  that  it  will  be  finished  in  three  years. 
There  are  but  three  stations  formed  at 
present.  There  will  be  one  more,  mak- 
ing four  from  Navy  Bay  to  Gorgona,  as 
follows : — 1st,  Navy  Bay,  the  commence- 
ment; 2d,  Gatun,  about  7  miles  from 
Navy  Bay ;  3d,  Bohia  Soldado,  (soldier's 
camp);  4th,  Juan  Grand,  (Great  John.) 
The  distance  from  Navy  Bay  to  Gorgona, 
by  railroad,  is  28  miles  ;  the  Chagres 
Kiver  will  be  crossed  by  a  bridge,  \\ 
miles  this  side  of  Gorgona.  Nothing  has 
been  done  or  commenced  on  the  other 
side  of  Gorgona,  nor  will  there  be  until 
this  is  finished.    There  will  be  some  stu- 

fiendous  work  between  Gorgona  and 
'anatiia — a  tunnel  is  to  be  made  of  about 
3,000  feet. 

The  air  line  distance  from  Chagres  to 
Panama,  is  30J  miles.  The  highest  point 
of  land  on  the  line  of  road  between  Gor- 
gona and  Panama  is  320  feet  above  the 
Pacific.  The  Pacific  is  12  feet  6-100  high- 
er than  the  Atlantic.  The  greatest  rise 
of  water  known  at  Panama,  22  feet ;  the 
least,  10.  There  are  swamps  between 
Navy  Bay  and  Gatun  2£  feet  lower  than 
the  Atlantic.  The  grade  of  the  road  from 
Navy  Bay  to  Gorgona,  26  feet  to  the  mile; 
Gorgona  to  Panama,  by  mule  path,  22 
miles ;  Cruces  to  Panama,  by  mule  path, 
17  miles ;  Isthmus  of  Tehuantepec,  air 
line  distance  between  the  Atlantic  and 
the  Pacific,  132  miles  ;  Nicaragua,  air  line 
distance  between  the  Atlantic  and  the 
Pacific,  90  miles. 

Railway,  Pneumatic  or  Atmospheric. 
Tho  name  given  to  a  system  of  locomo- 


tion on  railways  by  means  of  the  pressuro 
of  the  atmosphere.  A  simple  and  ingen- 
ious apparatus  for  this  purpose  was  in- 
vented a  few  years  ago,  and  is  now  being 
exhibited  on  the  West  London  Railway  at 
Wormwood  Scrubs. 

The  Croydon  Railway,  in  England,  Mas 
worked  on  the  atmospheric  principle  for 
a  few  years.  The  Kingston  and  Dalkey 
Railway,  Ireland  (2£  miles),  was  also  laid 
down  in  single  line  on  the  atmospheric 
principle.  The  tube  in  which  the  air  to 
be  removed  was  contained  was  placed  in 
connection  with  a  steam  pump,  which 
produced  a  vacuum,  and  dragged  the  car 
on  which  was  attached  to  the  movable 
piston  in  the  tube.  The  cars  were  drawn 
up  by  the  vacuum  to  the  Dalkey  terminus, 
and  returned  to  Kingston  by  gravity,  the 
inclination  of  the  line  being  very  great. 
The  expense  of  working  this  line  exceed- 
ed its  income  by  £700  per  year,  and  it 
consequently  was  given  up.  So  was  the 
Croydon  line,  from  a  similar  reason, 
though  the  rapidity  of  travel  is  probably 
greater  than  can  be  attained  by  a  locomo- 
tive :  on  this  latter  line  it  reached  the  rate 
of  75  miles  per  hour,  for  the  distance  of 
\  of  a  mile. 

The  defects  of  this  mode  of  working 
the  atmospheric  principle  has  led  to  vari- 
ous novel  recommendations,  none  of 
which  have  been  put  in  force. 

RAIN-GAUGE,  also  called  OMBRO- 
METER, UDOMETER,  and  PLUVIA- 
METER.  An  instrument  for  measuring 
or  gavging  the  quantity  of  rain  which  falls 
at  a  given  place. 

"  The  rain-gavge  may  be  of  very  sim- 
ple construction.  A  cubical  box  of  strong 
tin  or  zinc,  exactly  10  inches  by  the  side, 
open  above,  receives  at  an  incn  below  its 
edge  a  funnel,  sloping  to  a  small  hole  in 
the  centre.  On  one  of  the  lateral  edges 
of  the  box.  close  to  the  top  of  the  cavity, 
is  soldered  a  short  pipe,  in  which  a  cork 
is  fitted.  The  whole  should  be  well  paint- 
ed. The  water  which  enters  this  gauge 
is  poured  through  the  short  tube  into  a 
cylindrical  glass  vessel,  graduated  to  cubio 
inches  and  fifths  of  cubic  inches.    Hence, 


RAS] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


523 


one  inch  depth  of  rain  in  the  gauge  will 
be  measured  by  100  inches  of  the  gradu- 
ated vessel,  and  1 -100th  inch  of  rain  may 
be  very  easily  read  off. 

"It'is  very  much  to  be  desired  that, 
being  of  such  easy  construction,  more 
than  one  of  these  gauges  should  be  erect- 
ed ;  or  at  least  one  placed  with  its  edge 
nearly  level  with  the  ground,  and  another 
upon  the  top  of  the  highest  building,  rock, 
or  tree  in  the  immediate  vicinity  of  the 
place  of  observation,  the  height  of  which 
must  be  carefully  determined,  it  having 
been  satisfactorily  ascertained,  that  the 
height  of  the  gauge  above  the  ground  is 
a  very  material  element  of  the  quantity 
of  rain  which  enters  it.  The  quantity  of 
water  should  be  daily  measured  and  reg- 
istered at  9  a.  m." 

A  convenient  form  of  the  instrument 
is  represented  in  the  annexed  figure, 
where  the  rain  which 
enters  the  funnel  is 
collected  in  a  cylin- 
drical vessel  of  cop- 
per, connected  with 
which  at  the  lower 
part  is  a  glass  tube 
with  an  :  attached 
scale.  The  water 
stands  at  the  same 
height  in  the  cylinder 
and  glass  tube,  and 
being  visible  in  the 
latter,  the  height  is 
read  immediately  on 
the  scale;  and  the  cylinder  and  tube  be- 
ing constructed  so  that  the  sum  of  the 
areas  of  their  sections  is  a  given  part,  for 
instance  a  tenth  of  the  area  of  the  fun- 
nel at  its  orifice,  each  inch  of  water  in  the 
tube  is  equivalent  to  the  tenth  of  an 
inch  of  water  entering  the  mouth  of  the 
funnel.  A  stop-cock  is  added,  by  which 
the  water  is  drawn  off  when  the  obser- 
vation is  made. 

EASP,  MECHANICAL.  Is  the  name 
given  by  the  French  to  an  important  ma- 
chine much  used  for  mashing  beet-root. 
KATAFIA.  A  liqueur  prepared  from 
various  kinds  of  fruit,  and  named  after 
the  fruit  which  is  employed.  Ratafia  de 
cassio  has  cherries ;  ratafia  de  curacoa 
has  the  peels  of  Portugal  oranges  ;  ratafia 
d'angelique  has  anglician  seeds ;  ratafia 
d'anis  has  aniseed,  and  so  on.  The 
French  li querists  are  the  most  skilled  in 
this  as  in  most  branches  of  delicate  dis- 
tillation and  making  of  essences. 

RATCHET,  in  clock  and  watch  work, 
is  the  name  given  to  an  arm  or  piece  of 
mechanism,  one  extremity  of  which  abuts 


against  the  teeth  of  a  ratchet  wheel,  and 
the  other  extremity  is  either  freely  joint- 
ed to  a  reciprocating  driver  for  the  pur- 
pose of  communicating  a  .continuous  mo- 
tion to  the  wheel,  or  is  attached  to  a  fix- 
ed centre  to  insure  the  wheel  against  re- 
verse motion.  In  the  former  case  it  is  also 
called  a  click  or  paul,  in  the  latter,  a  detent. 

RATCHET  WHEEL.  A  wheel  having 
teeth  formed  like  those  of  a  saw,  against 
which  the  ratchet  abuts.    See  Ratchet. 

RAZOR.    See  Cutlery. 

REACTION.  A  termed  used  in  me- 
chanics to  denote  the  reciprocality  of 
force  exerted  upon  two  bodies  which  act 
mutually  on  each  other ;  or  the  general 
fact,  collected  from  observation,  that  any 
two  bodies  repelling  or  attracting  each 
other  are  made  to  recede  or  approach  with 
equal  momenta.  Newton's  third  law  of 
motion  is,  that  "reaction  is  always  con- 
trary and  equal  to  action,  or  that  the  mu- 
tual actions  of  two  bodies  are  always  equal, 
exerted  in  opposite  directions."  In  the 
mathematical  consideration  of  mechanics, 
this  principle  must  be  assumed  as  a  ne- 
cessary axiom  or  law ;  and,  in  fact,  as  is 
remarked  by  Dr.  Young,  there  would  be 
something  peculiar,  and  almost  inconceiv- 
able, in  a  force  which  could  affect  unequal- 
ly the  similar  particles  of  matter;  or  in 
the  particles  themselves,  if  they  could  be 
supposed  of  such  different  degrees  of  mo- 
bility as  to  be  equally  movable  with  re- 
spect to  one  force,  and  unequally  with  re- 
spect to  another.  The  principle  may, 
therefore,  as  justly  be  termed  a  necessary 
law  as  an  experimental  fact. 

REALGAR.     See  Arsenic. 

RECTIFICATION  is  the  final  purifica- 
tion of  liquors,  generally  alcohol,  by  dis- 
tillation. It  is  not  often  carried  on  un- 
der the  same  roof  with  the  distillation. 

Rectifiers  receive  malt  spirits  from  dis- 
tillers from  proof  to  25  per  cent.  Their 
business  is  to  re-distil  once  for  rectifica- 
tion. Then  to  distil  again  with  various 
vegetable  and  chemical  substances  so  as 
to  produce  flavors  called  gin,  hollands, 
brandy,  peppermint,  and  other  cordials. 
For  gin,  Italian  and  German  juniper-ber- 
ries, and  coriander-seeds.  Hollands  are 
made  from  rye-spirit,  flavored  with  juni- 
per and  other  ingredients.  See  Brandy, 
&c.  In  rectifying  spirits  for  gin,  proof 
is  reduced  to  17  and  22  per  cent,  under 
proof,  and  at  that  strength  sold  to  the 
dealers. 

In  the  trade  of  spirits,  there  is  the  dis- 
tiller, who  makes  the  spirit  from  the  fer- 
mented grain  and  wash ;  the  rectifier, 
who  concentrates,  compounds,  and  flavors 


524 


CYCLOPEDIA    OP    THE    USEFUL    ARTS. 


[rep 


it;  the  merchant-dealer ;  and  the  retailer, 
in  the  gin-shop  and  public-house. 

To  determine  the  probable  produce  of  I 
wines,   &c.,  intended  for  distillation,  a  j 
small  alembic  has  been  invented  at  Paris, 
adapted  to  heating  with  spirits  of  wine,  ! 
and  a  glass  vessel  used  as  a  recipient,  so 
that  a  single  glass  of  wine  mav  be  distilled,  j 
It  was  adopted  as  a  toy,  and  became  the  ; 
means  by  which  families  made  all  kinds  I 
of  flavored  waters.   The  leaves  of  orangos, 
roses,  &c,  &c,  were  laid  on  gratings 
above  the  water,  and  the  vapor  rising 
through  them  received   their  odor  and 
flavor.     The  whole  weighs  but  5  or  6  lbs. 
and  is  in  a  box  but  16  inches  long  and  3 
or  4  square. 

The  ordinary  method  of  conducting  the 
process,  consists  in  placing  the  liquid  to 
be  distilled  in  a  vessel  called  a  still  made 
of  copper,  having  a  moveable  head,  with 
a  swan  like  neck,  which  is  so  formed  as 
to  fit  a  coiled  tube  packed  away  in  a  tub 
of  water,  constantly  kept  cold,  and  which 
is  termed  a  refrigeratory  or  worm  tub. 
The  charge  of  a  wash  still  is  from 
16  to  20,000  gallons,  and  the  low-wines 
still  is  the  produce  of  the  wash  still, 
and  from  this  are  produced  spirits  and 
feints  in  separate  vessels.  The  feints  are 
turned  into  the  next  wash  still.  The 
spirits  are  then  sold  to  rectifiers,  who  re- 
distil, flavor,  and  prepare  for  consumption. 

A  liquid  obtained  by  distillation  is 
sometimes  not  perfectly  pure,  or  it  is  di- 
lute, from  the  intermixture  of  water,  that 
has  been  elevated  in  vapor  along  with  it. 
By  repeating  the  distillation  of  it  a  second 
or  a  third  time,  it  is  rendered  more  pure 
and  strong.  This  latter  process  is  named 
rectification,  or  sometimes  concentration. 

RED-LEAD.    See  Lead  and  Minium. 

EEED  is  the  well-known  implement  of 
the  weaver,  made  of  parallel  slips  of  metal 
or  reeds,  called  dents.  A  thorough  know- 
ledge of  the  adaptation  of  yarn  of  a  proper 
degree  of  fineness  to  any  given  measure  of 
reed,  constitutes  one  of  the  principal  ob- 
jects of  the  manufacturer  of  cloths ;  as 
upon  this  depends  entirely  the  appear- 
ance, and  in  a  great  degree  the  durability, 
of  the  cloth  when  finished.  The  art  of 
performing  this  properly  is  known  by  the 
names  of  examining,  setting,  or  sleying, 
which  are  used  indiscriminately,  and 
mean  exactly  the  same  thing.  The  reed 
consists  of  two  parallel  pieces  of  wood, 
set  a  few  inches  apart,  and  they  are  of 
any  given  length,  as  a  yard,  a  yard  and  a 
quarter,  &c.  "The  division  of  the  yard 
being  into  halves,  quarters,  eighths,  and 
sixteenths,  the  breadth  of  a  web  is  gen- 


enerally  expressed  by  a  vulgar  fraction, 
as  l-4th,  4-4ths,  5-4ths,  6-4ths ;  and  the 
subdivisions  by  the  eighths  or  sixteenths, 
or  nails,  as  they  are  usually  called,  as 
7-Sths,  9-8ths,  ll-8ths,  &c,  or  13-1 6ths, 
15-16ths,  19-16ths,  &c.  In  Scotland,  the 
splits  of  cane  which  pass  between  the 
longitudinal  pieces  or  ribs  of  the  reed,  are 
expressed  by  hundreds,  porters,  and 
splits,  the  porter  is  20  splits,  or  l-5th  of 
a  hundred. 

The  number  of  threads  in  the  warp  of 
aveb  is  generally  ascertained  with  con- 
siderable precision  by  means  of  a  small 
magnifying  glass,  fitted  into  a  socket  of 
brass,  under  which  is  drilled  a  small 
round  hole  in  the  bottom  plate  of  the 
standard.  The  number  of  threads  visi- 
ble in  this  perforation,  ascertains  the 
number  of  threads  in  the  standard  mea- 
sure of  the  reed.  Tiiose  used  in  Scotland 
have  sometimes  four  perforations,  over 
any  one  of  which  the  glass  may  be  shifted. 
The  first  perforation  is  l-4th  of  an  inch 
in  diameter,  and  is  therefore  well  adapt- 
ed to  the  Stockport  mode  of  counting ; 
that  is  to  say,  for  ascertaining  the  num- 
ber of  ends  or  threads  per  inch  ;  the  se- 
cond is  adapted  for  the  Holland  reed, 
being  l-200th  part  of  40  inches ;  the  third 
is  l-700th  part  of  37  inches,  and  is  adapt- 
ed for  the  now  almost  universal  construc- 
tion of  Scotch  reeds;  and  the  fourth,  be- 
ing l-200th  of  34  inches,  is  intended  for 
the  French  cambrics.  Every  thread  ap- 
pearing in  these  respective  measures,  of 
course  represents  200  threads,  or  100 
splits,  in  the  standard  breadth  ;  and  thus 
the  quality  of  the  fabric  may  be  ascer- 
tained with  considerable  precision,  even 
after  the  cloth  has  undergone  repeated 
wettings,  either  at  the  bleaching-ground 
or  dye-work.  By  counting  the  other 
way,  the  proportion  which  the  woof  bears 
to  the  warp  is  also  known,  and  this  forms 
the  chief  use  of  the  glass  to  the  manufac- 
turer and  operative  weaver,  both  of  whom 
are  previously  acquainted  with  the  exact 
measure  of  the  reed. 

REFINING  OF  GOLD  AND  SIL- 
VER; called  also  Parting.  For  several 
uses  in  the  arts,  these  precious  metals  are 
required  in  an  absolutely  pure  state,  in 
which  alone  they  possess  their  malleabil- 
ity and  peculiar  properties  in  the  most 
eminent  degree.  Thus,  for  example, 
neither  gold  nor  silver  leaf  can  be  made 
of  the  requisite  fineness,  if  the  metals 
contain  the  smallest  portion  of  copper  al- 
loy. Till  within  these  ten  or  twelve 
year3;  the  parting  of  silver  from  gold  was 
effected  everywhere  by  nitric  acid. 


ref] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


525 


2.  On  parting  by  the  nitric  acid.  The 
principle  on  which  this  process  is  found- 
ed, is  the  fact  of  silver  being  soluble  in 
nitric  acid,  while  gold  is  insoluble  in  that 
menstruum.  If  the  proportion  of  gold  to 
that  of  silver  be  greater  than  one  to  two, 
then  the  particles  of  the  former  metal  so 
protect  or  envelope  those  of  the  latter, 
that  the  nitric  acid,  even  at  a  boiling  heat, 
remains  quite  inactive  on  the  alloy.  It  is 
indispensable,  therefore,  that  the  weight 
of  the  silver  be  at  least  double  that  of  the 
gold.  100  pounds  of  silver  take  38 
pounds  of  nitric  acid,  of  specific  gravity 
1-320,  for  oxidizement,  and  111  for  solu- 
tion of  the  oxide  ;  being  together  149  ; 
but  the  refiner  often  consumes,  in  acid 
of  the  above  strength,  more  than  double 
the  weight  of  silver,  which  shows  great 
waste,  owing  to  the  imperfect  means  of 
condensation  employed  for  recovering  the 
vapors  of  the  boiling  and  very  volatile 
acid. 

100  pounds  of  copper  require  130 
pounds  of  the  above  acid  for  oxidizement ; 
and  390  for  solution  of  the  oxide ;  being 
520  pounds  in  whole,  of  which  less  than 
\W\  part  could  be  recovered  by  the  above 
apparatus.  It  is  therefore  manifest  that 
it  is  desirable  to  employ  silver  pretty 
well  freed  from  copper  by  a  previous  pro- 
cess ;  and  always,  if  practicable,  a  silver 
containing  some  gold. 

In  parting  by  nitric  acid,  the  gold  gen- 
erally retains  a  little  silver  :  as  is  proved 
by  the  cloud  of  chloride  of  silver  which 
it  affords,  at  the  end  of  some  hours,  when 
dissolved  in  aqua  regia.  And  on  the 
other  hand,  the  silver  retains  a  little  gold. 
These  facts  induced  M.  Dize,  when  he 
was  inspector  of  the  French  mint,  to 
adopt  some  other  process,  which  would 
give  more  accurate  analytical  results  ;  and 
after  numerous  experiments,  he  ascertain- 
ed that  sulphuric  acid  presented  great  ad- 
vantages in  this  point  of  view,  since  with 
it  he  succeeded  in  detecting,  in  silver, 
quantites  of  gold  which  had  eluded  the 
other  plan  of  parting.  The  suggestion  of 
M.  Dize  has  been  since  universally  adopt- 
ed in  France.  M.  Costell,  about  nine  or 
ten  years  ago,  erected  in  Pomeroy  street, 
Old  Kent  road,  a  laboratory  upon  the 
French  plan,  for  parting  by  sulphuric 
acid ;  but  he  was  not  successful  in  his  en- 
terprise; and  since  he  relinquished  the 
business,  Mr.  Matheson  introduced  the 
same  system  into  our  Royal  Mint,  under 
the  management  of  M.  Costell's  French 
operatives.  In  the  Parisian  refineries, 
gold,  to  the  amount  of  one  thousandth 


part  of  the  weight,  has  been  extracted 
from  all  the  silver  which  had  been  pre- 
viously parted  by  the  nitric  acid  process  ; 
being  3,500  francs  in  value  upon  every 
thousand  killogrammes  of  silver. 

The  most  suitable  alloy  for  refining 
gold,  by  the  sulphuric  acid  process,  is  the 
compound  of  gold,  silver,  and  copper, 
having  a  standard  quality,  by  the  cupel, 
of  from  900  to  950  milliemes,  and  contain- 
ing one  fifth  of  its  weight  of  gold.  The 
best  proportions  of  the  three  metals  are 
the  following :— silver,  725 ;  gold,  200  ; 
copper,  75;=1000.  It  has  been  found 
that  alloys  which  contain  more  copper 
afford  solutions  that  hold  some  anhydrous 
sulphate  of  that  metal  in  solution/which 
prevents  the  gold  from  being  readily  se- 
parated ;  and  that  alloys  containing  more 
gold  are  not  acted  on  easily  by  the  sul- 
phuric acid.  The  refiner  ought,  therefore, 
when  at  all  convenient,  to  reduce  the  al- 
loys that  he  lias  to  treat  to  the  above 
stated  proportions.    He  may  effect  this 

Jmrpose  either  by  fusing  the  coarser  al- 
oys  with  nitre  in  a  crucible,  or  by  add- 
ing finer  alloys,  or  .even  fine  silver,  or 
finally,  by  subjecting  the  coarser  alloys 
to  a  previous  cupellation  with  lead  on  the 
great  scale.  As  to  gold  or  silver  bullion, 
which  contains  lead  and  other  easily  ox- 
idizable  metals  besides  copper,  the  refiner 
ought  always  to  avoid  treating  them  by 
sulphuric  acid  ;  and  should  separate,  first 
of  all,  these  foreign  metals  by  the  agency 
of  nitre,  if  they  exist  in  minute  quantity ; 
but  if  in  larger,  he  should  have  recourse 
to  the  cupel.  Great  advantage  will  there- 
fore be  derived  from  the  judicious  pre- 
paration of  the  alloy  to  be  refined. 

For  an  alloy  of  the  above  description, 
the  principal'Parisian  refiners  are  in  the 
habit  of  employing  thrice  its  weight  of 
sulphuric  acid, 'in  order  to  obtain  a  clear 
solution  of  sulphate  of  silver,  which  does 
not  too  suddenly  concrete  on  cooling,  so 
as  to  obstruct  its  discharge  from  the 
alembic  by  decantation.  A  small  increase 
in  the  quantity  of  copper  calls  for  a  con- 
siderable increase  in  the  quantity  of  acid. 
Generally  speaking,  one  half  of  the  sul- 
phuric acid  strictly  required  for  convert- 
ing the  silver  and  copper  into  sulphates, 
is  decomposed  into  sulphurous  acid, 
which  is  lost  to  the  manufacturer,  unless 
he  has  recourse  to  the  agency  of  nitrous 
acid. 

The  Parisian  refiners  restore  to  the 
owners  the  whole  of  the  gold  and  silver 
contained  in  the  ingots,  reserving  to  them- 
selves the  copper  which  formed  the  alloy, 


526 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[reg 


and  charging  only  the  sum  of  5i  francs 
per  killogramme  (2-68  lbs.  troy)  for  the 
expense  of  the  parting  of  the  metals. 

If  they  are  employed  to  refine  an  ingot 
of  silver  containing  less  than  one  tenth  of 
gold,  they  retain  for  themselves  a  two 
thousandth  part  of  the  gold,  and  all  the 
copper,  existing  in  the  alloy ;  return  all 
the  rest  of  the  gold,  with  the'whole  of  the 
silver,  in  the  ingot;  and  give,  besides,  to 
the  owners  a  premium  or  bonus,  which 
amounted  lately  to  fths  of  a  franc  on  the 
kilogramme  of  metal.  Should  the  owner 
desire  to  have  the  whole  of  the  gold  and 
silver  contained  in  his  ingot,  the  refiner 
then  demands  from  him  2  francs  and  68 
centimes  per  kilogramme,  retaining  the 
copper  of  the  alloy.  As  to  silver  ingots 
of  low  standard,  the  perfection  of  the  re- 
fining process  is  such,  that  the  mere  cop- 
per contained  in  them  pays  all  the  costs  ; 
lor  in  this  case,  the  refiner  restores  to  the 
proprietor  of  the  ingot  as  much  fine  silver 
as  the  assay  indicated  to  exist  in  the  in- 
got, contenting  himself  with  the  copper 
}f  the  allov. 

REFLECTING  CIRCLE.  An  astro- 
nomical instrument  for  the  measurement 
of  angles  by  reflection.  See  Sextant. 
The  term  is  also  applied  to  a  surveying 
instrument,  invented  by  Sir  Howard 
Douglas,  which  combines  the  advantages 
of  the  Hadley's  quadrant  and  the  pro- 
tractor. The  object  of  it  is  to  protract, 
or  lav  down  on  the  plan,  the  angles  mea- 
sured with  the  instrument  from  the  in- 
strument itself,  without  any  intermediate 
step,  or  even  a  register  of  their  values. 
The  advantage  of  such  an  instrument 
must  be  obvious  in  military  surveys, 
where  expedition  is  important,  while  ac- 
curacy is  thereby  far  more  efficiently  in- 
sured than  by  the  old  and  more  tedious 
process.  It  is  also  advantageously  used 
in  forming  general  sketches  of  a  country. 

To  improve  it,  J.  C.  Dennis  suggests : 
— Instead  of  attaching  the  circle,  technic- 
ally called  an  arc,  to  the  parts  which  sup- 
port it,  let  the  whole  be  cast  in  one  piece, 
then  placed,  polished,  or  divided,  to  suit 
the  purposes  of  modern  astronomy.  This 
intrument  is  capable  of  distinguishing  to 
the  5940th  part  of  an  inch. 

REFLEXION,  in  mechanics,  denotes 
the  rebound  or  regressive  motion  of  a 
body  from  the  surface  of  another  body 
against  which  it  impinges.  In  natural 
philosophy,  the  term  is  applied  to  the 
analogous  motions  of  light,  heat,  and 
sound,  when  turned  from  their  course  by 
an  opposing  surface.  The  laws  of  tho  re- 
flexion of  light  form  the  branch  of  science 


called  catoptric*  ;  those  of  the  reflexion  of 
sound  are  sometimes  called  cataphonics. 

The  simplest  view  which  can  be  taken 
of  the  mechanical  action  whereby  reflex- 
ion is  produced,  is  to  assimilate  it  to  that 
which  takes  place  when  an  elastic  body 
impinges  on  another  body  which  it  can- 
not move  out  of  its  place.  If  light,  heat, 
and  sound  are  propagated  by  the  pulses 
of  an  elastic  medium,  the  same  theory 
will  apply  to  them ;  and  it  is  to  be  re- 
marked, that  in  all  cases  of  reflexion  the 
change  of  motion  which  takes  place  fol- 
lows precisely  the  same  laws  as  that  which 
is  produced  by  the  impact  of  two  elastic 
bodies. 

REGULATOR.  In  machinery,  a  gen- 
eral name  for  any  contrivance  of  which 
the  object  is  to  produce  the  uniform 
movement  of  machines.  The  regulators 
most  commonly  applied  are  the  fly  and 
the  governor,  for  which  see  the  respective 
terms. 

The  regulator  of  a  watch  is  the  spiral 
spring  attached  to  the  balance.    This  in- 

Senious  contrivance,  the  invention  of 
[ooke,  has  contributed  as  much  to  the 
improvement  of  watches  as  the  pendulum 
to  the  improvement  of  clocks. 

The  present  Astronomer  Royal  of  En- 
gland has  investigated  the  mathematical 
problem  of  the  motion  of  the  regulator 
applied  to  the  clock-work  by  which  mo- 
tion is  given  to  large  equatorial  telescopes. 
For  this  purpose,  absolute  uniformity  of 
motion  is  of  very  great  importance.  The 
construction,  usually  adopted,  in  this 
country  at  least,  depends  on  the  same 
principle  a3  that  of  the  governor  of  the 
steam-engine.  Two  balls,  suspended 
from  the'upper  part  of  a  vertical  axis  by 
rods  of  a  certain  length  i  are  made  to  ex- 
pand by  the  rotatory  velocity  of  the  axis ; 
and  when  the  expansion  reaches  a  certain 
limit,  a  lever  is  pressed  against  some  re- 
volving part,  whereby  a  friction  is  pro- 
duced "which  immediately  checks  the  ve- 
locity. Now  the  uniformity  of  the  ro- 
tatory motion  of  the  spindle  depends  up- 
on the  assumption,  that  if  upon  the  whole 
the  retarding  forces  are  equal  to  the  ac- 
celerating forces,  the  balls  will  move  in  a 
circle,  and  in  no  other  curve.  But  this 
assumption  is  incorrect;  for  the  balls  may 
move  in  a  curve  differing  insensibly  from 
an  ellipse ;  and,  in  some  instances,  Mr. 
Airy  observed  the  balls  to  revolve  in  an 
ellipse  of  considerable  eccentricity. 
When  this  takes  place,  the  rotatory  mo- 
tion of  the  spindle  becomes  exceedingly 
variable.  This  injurious  effect  may  be 
partly  counteracted  by  constructing  the 


I] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


521 


apparatus  so  that  the  revolutions  shall  be 
either  very  slow  or  very  quick  ;  the  for- 
mer method  has  the  effect  of  giving  great- 
er smoothness  of  motion,  but  the  second 
insures  more  completely  that  the  object 
observed  shall  remain  steady  in  the  field 
of  the  telescope. 

BELIEF.  In  architecture,  the  projec- 
tion of  a  figure  or  ornament  from  the 
f  round  or  plane  on  which  it  is  sculptured, 
n  sculpture,  when  the  whole  of  the  figure 
stands  out,  the  work  is  denominated  alto- 
relievo;  when  only  half  out,  demi-relievo  ; 
and  wiien  its  projection  is  very  small,  it 
is  called  basso-relievo. 

Belief,  Relievo.  In  sculpture,  that 
species  of  sculpture  in  which  the  figures 
are  engaged  on  or  rise  from  a  ground. 
There  are"  three  sorts  of  relievo — basso  re- 
lievo, in  which  the  figures  or  other  objects 
have  but  small  projection  from  the  ground 
on  which  they  are  sculptured ' .mezzo-re- 
lievo, in  which  the  figures  stand  out  about 
half  their  natural  proportions,  the  other 
half  appearing  immersed  in  the  ground ; 
and,  lastly,  alto-relievo,  in  which  the  fig- 
ures stand  completely  out  from  the 
ground,  being  attached  to  it  only  in  a  few 
places,  and  in  others  worked  entirely 
round  like  single  statues ;  such  are  the 
metopae  of  the  Elgin  marbles  in  the  Brit- 
ish Museum,  which  marbles  also,  in  the 
Panathenaic  procession,  exhibit  some  ex- 
quisite examples  of  basso-relievo. 

EEPEATING  C1ECLE.  In  order  to 
diminish  the  effect  of  errors  of  gradua- 
tion, and  to  obtain  very  accurate  measure- 
ments by  means  of  comparatively  small, 
and,  therefore,  portable  instruments,  a 
method  of  observing  was  invented,  or 
rather  brought  into  use,  by  Borda,  which 
is  now  extensively  employed,  especially 
in  geodetical  operations.  The  method, 
which  consists  m  moving  the  telescope 
successively  over  portions  of  the  gradua- 
ted limb  corresponding  to  the  angle  to  be 
measured,  and  reading  only  the  multiple 
arc,  may  be  advantageously  applied  to 
circular  instruments  "destined  for  very 
different  purposes:  as,  for  example,  to 
an  instrument  for  the  measurement  of 
the  zenith  distances  of  stars  or  terrestrial 
objects,  or  the  distance  of  two  trigono- 
metrical stations,  in  which  case  it  is  sim- 
ply called  called  repeating  circle  ;  to  a  re- 
flecting circle  used  for  observations  at 
sea,  when  it  becomes  a  repeating  reflecting 
circle  ;  or  to  a  theodolite,  when  it  becomes 
a  repeating  theodolite. 

When  the  repeating  circle  is  used  for 
measuring  zenith  distances,  it  is  con- 
structed so  as   to  be  capable  of  being 


turned  round  on  a  vertical  pivot,  the  di- 
rection of  which  passes  through  its  cen- 
tre, and  to  which  its  plane  is  parallel,  and 
also  of  turning  in  its  own  plane  about  a 
horizontal  axis.  The  instrument  being 
placed  in  the  same  vertical  plane  with  the 
star,  the  telescope  is  directed  to  the  star 
and  the  bisection  made  ;  the  telescope, 
which  carries  the  verniers  with  it,  is 
then  firmly  clamped  to  the  circle,  and 
the  circle  turned  round  180°  in  azimuth 
about  the  vertical  pivot.  If  the  circle  be 
now  kept  fast,  the  telescope  undamped 
and  carried  round  till  the  star  is  again 
bisected,  it  is  plain  that  the  arc  of  the 
limb  passed  over  by  the  verniers  in  conse- 
quence of  this  motion  of  the  telescope 
will  be  double  the  zenith  distance  of  the 
star.  The  same  process  is  repeated  as 
often  as  may  be  thought  necessary.  For 
the  purpose  of  geodetical  measurements 
the  circle  is  usually  furnished  with  two 
telescopes,  one  on  the  face,  and  the  other 
on  the  back  ;  and  so  placed  that  the  opti- 
cal axes  of  both  are  exactly  in  the  plane 
of  the  circle.  The  circles  used  by  Me- 
chain  and  Belambre  in  the  operations  con- 
nected with  the  measurement  of  the 
French  arc  of  meridian,  were  about 
4-10ths  of  a  metre  (nearly  16  inches)  in 
diameter,  and  were  divided  into  arcs 
equivalent  to  about  32  sexagesimal  se- 
conds, which  were  subdivided  into  tenths 
by  the  verniers. 

The  merit  of  first  applying  the  ingen  ■ 
ious  principle  of  repetition  to  angular 
measurements,  belongs  to  Tobias  Mayer, 
but  it  was  Borda,  as  above  stated,  who 
first  brought  the  instrument  into  general 
use.  For  a  description  of  the  repeating 
circle,  its  adjustment,  and  the  method  of 
using  it,  see  Biot.  Astronomie  Physique, 
tomei.;  Delambre  Astronomie  on  Base 
Metrique,  tome  i.,  Puissant  traite  de  Ge- 
odesie  ;  Boper's  Practice  of  Navigation. 
The  comparative  advantages  and  defects 
of  the  instrument  are  very  clearly  stated 
in  a  paper  by  Tronghton,  in  the  1st  vol- 
ume of  the  Memoirs  of  the  Boyal  Astro- 
nomical Society. 

BESINS  are  proximate  principles 
found  in  most  vegetables,  and  in  almost 
every  part  of  them  ;  but  the  only  resins 
which  merit  a  particular  description,  are 
those  which  occur  naturally  in  such 
quantities  as  to  be  easily  collected  or  ex- 
tracted. They  are  obtained  chiefly  in 
two  ways,  either  by  spontaneous  exuda- 
tion from  the  plants,  or  by  extraction  by 
heat  and  alcohol.  In  the*  first  case,  the 
discharge  of  resin  in  the  liquid  state  is 
sometimes    promoted  by  artificial  inci- 


528 


CYCLOPEDIA    OF    THE    USEFUL  _ ARTS. 


[» 


sions  made  in  summer  through  the  bark 
into  the  wood  of  the  tree. 

.Resins  possess  the  following  general 
properties  : — They  are  soluble  in  alcohol, 
insoluble  in  water,  and  melt  by  the  ap- 
plication of  heat,  but  do  not  volatilize 
without  partial  decomposition.  They 
have  rarely  a  crystalline  structure,  but, 
like  gums,  they  have  no  particular  form. 
They  ignite  readily,  burn  with  a  bright 
light,  and  give  much  smoke.  They  are 
quite  insoluble  in  water,  but  dissolve 
readily  in  cold  and  hot  alcohol,  from 
which  they  are  precipitated  by  water. 
Eesins  dissolve  in  ether  and  volatile  oils, 
and  by  heat  combine  with  fat  oils.  They 
mix  with  sulphur  and  phosphorus.  Car- 
buret of  sulphur  dissolves  them,  chlorine 
bleaches  them,  and  nitric  acid  converts 
them  into  artificial  tan.  Every  natural 
resin  is  a  compound  of  two  or  three  pure 
resins,  as  is  the  case  with  oils.  Some 
are  soluble  in  hot  or  cold  alcohol — ether, 
naptha,  and  turpentine.  Resins  which 
contain  essential  oil  are  called  balsams  • 
a  few  contain  benzoin  acids.  The  solid 
resins  are  amber,  anime,  benzoin,  colo- 

Ehony  copal,  copal,  danunara,  dragon's 
lood,  elemi,  gniac,  lac,  jalap  resin, 
ladanum,  mastic,  sandarach,  storax,  taca- 
mahac. 

An  ingenious  memoir  upon  the  resins 
of  dammar,  copal,  and  anime,  has  lately 
been  published  by  M.  Guibourt,  an  emi- 
nent French  pkarmacien ,  from  which  the 
following  extract  may  be  found  interest- 
ing. 

The  hard  copal  of  India  and  Africa, 
especially  Madagascar,  is  the  product  of 
the  hymencm  verrucosa  ;  it  is  transparent 
and  vitreous  within,  whatever  may  be 
its  appearance  outside ;  nearly  colorless, 
or  of  a  tawny  yellow ;  without  taste  or 
smell  in  the  cold,  and  almost  as  hard  as 
amber,  which  it  much  resembles,  but 
from  which  it  may  be  distinguished, 
1st,  by  its  smelting  and  kindling  at  a 
candle-flame,  and  running  down  in  drops, 
while  amber  burns  and  swells  up  with- 
out flowing ;  2dly,  this  hard  copal  or 
anime,  when  blown  out  and  still  hot, 
exhales  a  smell  like  balsam  copaiva  or 
capivi :  while  amber  exhales  an  unplea- 
sant bituminous  odor;  3dly,  when  moist- 
ened by  alcohol  of  85  per  cent.,  copal 
becomes  sticky,  and  shows  after  drying 
a  glazed  opaque  surface,  while  amber  is 
not  affected  by  alcohol ;  4thly,  the  copal 
affords  no  succinic  acid,  as  amber  does, 
on  distillation. 

When  the  pulverized  copal  is  digested 
in  cold  alcohol  of  0*830,  it  leaves  a  con- 


siderable residuum,  at  first  pulverulent, 
but  which  swells  afterward,  and  forms  a 
slightly  coherent  mass.  When  this  pow- 
der is  treated  with  boiling  alcohol,  it 
assumes  the  consistence  of  a  thick  gluten, 
like  crumbs  of  bread,  but  which  does  not 
stick  to  the  fingers. 

RESISTANCE,  in  mechanics,  denotes 
generally  a  force  acting  in  opposition  to 
another  force,  so  as  destroy  it  or  diminish 
its  effect.  Resistance  is  sometimes  con- 
sidered as  of  two  kinds,  active  and  pas- 
sive;  the  active  resistance  being  that 
which  corresponds  to  the  useful  effect 
produced  by  a  machine,  and  the  passive 
that  which  belongs  to  the  inertia  of  the 
machine.  Thus,  in  raising  water  from  a 
well,  the  active  resistance  to  the  force 
employed  is  measured  by  the  quantity  of 
water  which  is  raised ;  and  the  passive 
resistance  by  the  force  required  to  over- 
come the  weight  of  the  bucket  and  the 
rope,  the  friction  of  the  pulley  on  its 
axle,  &c. 

RESISTANCE  OF  FLUIDS.  In 
hydrodynamics,  the  force  with  which  a 
solid  body  moving  through  a  fluid  is  re- 
sisted or  retarded.  Of  all  the  different 
kinds  of  resistance  which  manifest  them- 
selves among  bodies,  there  is  none  of 
greater  importance  than  this,  on  account 
of  its  application  to  the  theory  of  naval 
architecture. 

Sir  Isaac  Newton  was  the  first  who 
gave  a  general  theory  of  the  motions  and 
actions  of  fluids.    The  Newtonian  theory 
of  the  resistance  of  fluids,  which  is  given 
j  in  the  second  book  of  the  Princvpia.,  is 
founded  en  the  assumption  of  the  per- 
fect intermobility  of  the  particles  of  the 
fluid,  and  the  equal  propagation  of  pres- 
sure in  all  directions.     These  are,  indeed, 
the  characteristic  properties  of  fluidity ; 
nevertheless,  the  results  of  the  mathe- 
matical theory  differ  so  widely  in  many 
cases  from  actual  experiment,  that  some 
|  philosophers  have  called  in  question  the 
I  accuracy  of  the   principles   from   which 
!  they  are  derived.    The  theory,  however, 
!  notwithstanding    its    defects,    furnishes 
I  some  propositions  of  great  practical  use, 
:  and,  indeed,  forms  the  groundwork  of 
:  all  our  knowledge  on  the  subject. 

It  is  evident  that  a  solid  body,  in  mov- 
:  iug  through  a  fluid,  must  communicate  a 
:  motion  to  the  fluid  particles  with  which 
■  it  successively  comes  in  contact.     Now, 
the  quantity  of  motion  communicated  to 
the  fluid    is    necessarily  equal   to  that 
which  is  lost  by  the  solid,  and  may  there- 
fore be  taken  as  the  measure  of  the  re- 
;  sistance.    To  determine  this  quantity  of 


res] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


529 


motion,  let  us  conceive  a  cylindrical  or 
prismatic  body,  terminated  by  a  plane 
perpendicular  to  its  axis,  to  be  propelled 
through  a  non-elastic  fluid  in  the  direc- 
tion of  its  axis,  so  that  the  particles  of 
the  fluid  strike  against  the  plane  perpen- 
dicularly. 

Numerous  experiments  have  been  made 
for  the  purpose  of  ascertaining  how  far 
the  theory  of  the  resistance  of  fluids 
agrees  with  the  actual  facts,  or  for  form- 
ing an  empirical  theory  for  the  guidance 
of  the  engineer.  Of  the  details  of  these 
experiments  our  limits  will  not  permit  us 
to  give  an  account.  The  general  results 
of  the  experiments  may  be  stated  as  fol- 
lows :— 

I.  The  force  of  resistance  on  bodies 
moving  in  fluids  is  proportional  to  the 
square  of  the  velocity,  at  least  within  the 
limits  of  2  to  10  feet  per  second.  This  is 
in  accordance  with  the  theory. 

II.  The  direct  resistance  on  bodies 
moving  with  the  3ame  velocities  is  nearly 
in  the  ratio  of  the  surfaces. 

III.  The  resistances  on  surfaces  mov- 
ing obliquely  do  not  by  any  means  vary 
in  the  ratio  of  the  squares  of  the  sines  of 
the  angles  of  incidence,  especially  when 
the  incidence  is  very  oblique ;  and  for 
such  motions  the  theory  must  be  entirely 
abandoned. 

The  above  results  are,  however,  con- 
siderably modified  by  various  circum- 
stances, of  which  the  principal  are  the 
following : — 

1.  The  form  of  the  body.  The  New- 
tonian theory  takes  account  only  of  the 
anterior  surface  of  the  body  ;  but  it  was 
clearly  established  by  the  experiments  of 
Du  Buat  that  the  form  of  the  hinder  part 
is  not  less  efficacious  in  modifying  the 
resistance.  A  prismatic  body,  having  its 
prow  and  poop  equal  and  parallel  sur- 
faces, being  plunged  horizontally  into  a 
stream,  will  require,  in  order  to  keep  it 
immovable,  a  force  in  the  direction  of 
its  axis  equal  to  the  difference  of  the  real 
pressure  exerted  on  its  prow  and  poop. 
If  the  fluid  is  at  rest,  this  difference  will 
be  nothing,  because  the  opposite  dead 
pressures  are  equal;  but  in  a  stream 
there  is  superadded  to  the  dead  pressure 
on  the  prow  the  active  pressure  arising 
from  the  deflection  of  the  filaments  of  the 
fluid,  which  being  turned  aside  and  ren- 
dered divergent  by  the  obstruction  of  the 
anterior  surface,  a  part  of  the  pressure  of 
the  circumambient  fluid  is  employed  in 
turning  them  into  the  trough  behind  the 
body,  and  consequently  there  is  less 
pressure  on  the  posterior  surface  than  if 
23 


the  body  were  at  rest  in  stagnant  water, 
so  that  the  body  is  impelled  backwards. 
This  force  is  called  by  Du  Buat  the  non 
j)ressvre  ;  by  Bcaufoy  the  minus  pressure. 
Now,  the  whole  impulse  to  be  withstood 
if  the  body  is  in  a  stream,  or  the  resist- 
ance to  be  overcome  if  it  moves  in  stag- 
nant water,  is  the  sum  of  the  active  pres- 
sure on  the  fore  part  and  the  non-pres- 
sure on  the  hinder  part ;  and  this  does 
not  depend  solely  on  the  form  of  the 
prow  and  poop,  but  also,  and  perhaps 
chiefly,  on  the  length  of  the  body.  The 
non-pressure  on  a  cube  was  found  by 
experiment  to  be  reduced  to  a  fourth 
part,  by  making  the  length  of  the  body 
triple  of  the  breadth.  The  mere  length- 
ening of  a  ship,  without  changing  the 
form  of  the  prow  or  poop,  increases  the 
speed. 

2.  Another  circumstance  which  modi- 
fies the  general  results  is  the  velocity  of 
the  body.  It  was  ascertained,  by  Mr. 
Russell's  experiments  on  canal  boats, 
that  the  resistance  does  not  follow  the 
ratio  of  the  squares  of  the  velocities,  ex- 
cepting when  the  velocity  is  small  and 
the  depth  considerable ;  but  that  the  in- 
crements of  the  resistance  are  greater 
than  those  due  to  the  squares  of  the  ve- 
locities as  the  velocity  approaches  to  a 
certain  limit  depending  on  the  depth  of 
the  fluid ;  and  that  immediately  after 
passing  this  limit  the  resistance  suffers 
a  sudden  diminution,  and  becomes  much 
less  than  that  due  to  the  square  of  the 
velocity.  In  a  canal  about  five  and  a  half 
feet  deep,  this  limit  (which  is  the  velo- 
city of  the  wave  generated  by  the  motion 
of  the  body)  was  found  to  be  from  11  to 
12  feet  per  second,  or  about  eight  miles 
per  hour. 

3.  A  third  cause  which  modifies  the 
theory  is  the  adhesion  of  the  molecules  of 
the  fluid,  which  is  most  sensible  when 
the  motion  is  slow  and  the  body  small 
and  very  long.  In  such  cases,  it  becomes 
necessary  to  add  a  term  depending  on 
the  first  power  of  the  velocity. 

4.  The  resistance  is  also  influenced  by 
the  depth  of  the  body  under  the  surface 
of  the  water.  When  the  body  is  near 
the  surface  the  resistance  is  greater  than 
when  it  is  at  the  depth  of  six  feet.  When 
a  body  floats,  the  fluid  is  heaped  up,  as 
it  were,  before  the  anterior  surface,  by 
which  the  resistance  is  increased. 

5.  In  elastic  fluids,  as  the  density  in- 
creases with  the  pressure,  the  density  of 
the  fluid  before  the  anterior  surface  in- 
creases with  the  velocity,  and  the  incr<»- 
ments  of  the  resistance  are  greater  than 


530 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[rho 


in  the  ratio  of  the  square  of  the  velocity. 
In  this  case,  also,  we  may  conceive  a  ve- 
locity so  great  that  the  pressure  on  the 
posterior  surface  becomes  negative,  as  in 
the  case  of  a  cannon  hall  projected  with 
a  velocity  greater  than  that  with  which 
air  rushes  into  a  vacuum.  When  this 
takes  place  the  fluid  is  not  even  in  con- 
tact with  the  posterior  surfaces  of  the 
ball,  and  the  character  of  the  resistance 
is  wholly  changed. 

6.  "When  a  body  moves  in  a  fluid  a 
portion  of  the  fluid  adheres  to  the  body, 
and  accompanies  it  in  its  motion ;  where- 
by the  form  of  the  moving  body  is  alter- 
ed, and  the  resistance  increased.  The 
quantity  of  fluid  thus  dragged  along  is 
independent  of  the  velocity,  and  was  esti- 
mated by  Du  Buat,  from  experiments 
made  on  spheres  vibrating  in  water,  to 
increase  the  quantity  of  displaced  fluid  in 
the  ratio  of  1  to  1-6.  His  experiments 
on  prisms  also  showed  that  the  quantity 
of  dragged  fluid  was  proportional  to  the 
bulk  ot  the  moving  body.  Mr.  Baily 
gives,  as  the  mean  results  of  his  experi- 
ments on  pendulums  swinging  in  air, 
the  ratio  1  to  1-846  as  the  increase  of  the 
displaced  fluid  from  this  cause  ;  and  re- 
marks that  the  quantity  appeared  to  de- 
pend on  the  form  as  well  as  magnitude 
of  the  moving  body,  but  not  on  its  weight 
or  specific  gravity.  This  circumstance, 
which  considerably  modifies  the  resist- 
ance, though  made  known  by  Du  Buat 
in  1786,  was  overlooked  by  other  experi- 
menters, until  re-discovered  by  Bessel  in 
1826,  when  engaged  on  experiments  to 
determine  the  length  of  the  seconds'  pen- 
dulum. 

RESPIRATOR.  A  medium  through 
which  the  air  is  carried  before  it  enters 
the  mouth  and  lungs.  There  are  various 
forms  of  these  instruments. 

A  Mr.  A.  S.  Lyman,  inventor  of  the 
Safety  Steam  and  Water  Gauge,  which 
bears  his  name,  has  invented  a  beautiful 
apparatus,  for  inhaling  medicated  vapors 
by  sick  persons,  and  also  to  purify  the 
atmosphere,  which  may  be  inhaled  by 
any  person.  The  latter  quality  of  this 
neat  apparatus  will  enable  a  person  to  go 
into,  or  labor  in  a  deleterious  atmos- 
phere, without  danger.  A  small  cap- 
shaped  reservoir  of  light  material  is  fas- 
tened on  the  head  with  a  neat  tube  se- 
cured to  it,  in  such  a  manner  that  the 
wearer  only  inhales  through  it.  This 
tube  communicates  with  the  atmosphere 
and  with  the  small  cap  reservoir,  which 
contains  some  purifying  or  disinfecting 
substance,  such  as  moist  lime,  or  fine 


charcoal,  which  absorbs  impurities  from 
the  atmosphere,  and  allows  the  pure  air 
onlv  to  be  taken  in  by  the  limes. 

tfETINASPHALTUM  or  RETINITE. 
A  substance  discovered  by  Mr.  Hatchctt, 
associated  with  Bovey  coal,  and  which 
has  since  been  found  in  other  coal  strata. 
When  digested  in  alcohol  it  yields  a  por- 
tion of  resin,  and  asphaltum  remains ; 
it  appears,  therefore,  to  be  a  substance 
intermediate  between  resin  and  bitumen, 
and  renders  it  probable  that  bitumens 
are  of  resinous  origin. 

EETOKT.  A  glass,  metal,  or  earthen 
vessel,  used  in  the  distillation  of  chemical 
substances.  Retorts  of  clay  are  now  ex- 
tensively used  in  gas-making. 

REVERSING  MOTION,  is  a  very  im- 
portant principle  in  mechanics,  and,  in  a 
general  way,  says  Gregory,  is  effected 
"  by  making  two  equal  pinions  on  one 
and  the  same  axis,  turn  alternately  into 
the  teeth  of  those  parts  of  a  larger  wheel 
which  are  nearly  diametrically  opposite  ; 
or,  by  means  of  an  additional  wheel, 
which  may  be  thrown  in  or  out  of  gear 
alternately." 

REVERBERATING  FURNACE,  is 
that  in  which  the  roasting  of  metals  and 
the  puddling  of  iron  is  chiefly  conducted. 
Its  particular  form  varies,  but  the  gene- 
ral principle  of  its  construction  is  to  have 
the  rojf  or  vault  of  the  furnace  so  arched 
as  to  throw  down  or  reverberate  the 
flame  and  heated  air  upon  the  melted 
mass  below.  The  cut  illustrates  the  usual 
form  of  this  kind  of  furnace. 


RHODIUM,  is  a  metal  discovered  by 
Dr.  Wollaston  in  1803,  in  the  ore  of  pla- 
tinum. It  is  contained  to  the  amount  o/ 
three  per  cent,  in  the  platinum  ore 
of  Antioquia  in  Colombia,  near  Bar- 
bacoas  ;  it  occurs  in  the  Ural  ore,  and, 
alloyed  with  gold,  in  Mexico.  The  pal- 
ladium having  been  precipitated  from  the 
muriatic  solution  of  the  platinum  ore 
previously  saturated  with  soda,  by  the 
cyanide  of  mercury,  muriatic  acid  is  to 
be  poured  into  the  residuary  liquid,  and 
the  mixture  is  to  be  evaporated  to  dry- 


Ric] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


531 


ness,  to  expel  the  hydrocyanic  acid,  and 
convert  the  metallic  salts  into  chlorides. 
The  dry  mass  is  to  be  reduced  to  a  very 
fine  powder,  and  washed  with  alcohol  of 
specific  gravity  0-837.  This  solvent  takes 
possession  of  the  double  chlorides  which 
the  sodium  forms  with  the  platinum, 
iridium,  copper,  and  mercury,  and 
does  not  dissolve  the  double  chloride  of 
rhodium  and  sodium,  but  leaves  it  in  the 
form  of  a  powder,  of  a  fine  dark-red 
color.  This  salt  being  washed  with  alco- 
hol, and  then  exposed  to  a  very  strong 
heat,  affords  the  rhodium.  But  a  better 
mode  of  reducing  the  metal  upon  the 
small  scale,  consists  in  heating  the  double 
chloride  gently  in  a  glass  tube,  while  a 
stream  of  hydrogen  passes  over  it,  and 
then  to  wash  away  the  chloride  of  sodium 
with  water. 

Rhodium  resembles  platinum  in  appear- 
ance. Any  heat  which  can  be  produced 
in  a  chemical  furnace  is  incapable  of  fus- 
ing it ;  and  the  only  way  of  giving  it  co- 
hesive solidity,  is  to  calcine  the  sul- 
phurct  or  arseniuret  of  rhodium  in  an 
open  vessel  at  a  white  heat,  till  all  the 
sulphur  or  arsenic  be  expelled.  A  but- 
ton may  thus  be  obtained,  somewhat 
spongy,  having  the  color  and  lustre  of 
silver/  According  to  WoUaston,  the  spe- 
cific gravity  of  rhodium  is  11.  It  is  in- 
soluble by  itself  in  any  acid  ;  but  when 
an  alloy  of  it  with  certain  metals,  as  pla- 
tinum, copper,  bismuth  or  lead,  is  treat- 
ed with  aquaregia,  the  rhodium  dissolves 
along  with  the  other  metals  ;  but  when 
alloyed  with  gold  or  silver  it  will  not  dis- 
solve along  with  them.  It  may,  how- 
ever, be  rendered  very  soluble  by  mixing 
it  in  the  state  of  a  fine  powder  with  chlo- 
ride of  potassium  or  sodium,  and  heat- 
ing the  mixture  to  a  dull-red  heat,  in  a 
stream  of  chlorine  gas.  It  thus  forms  a 
triple  salt,  very  soluble  in  water.  The 
solutions  of  rhodium  are  of  a  beautiful 
rose  color,  whence  its  name.  In  the  dry 
way,  it  dissolves  by  heat  in  bisulphate  of 
potassa ;  and  disengages*  sulphurous  acid 
gas  in  the  act  of  solution.  There  are  two 
oxides  of  rhodium.  Rhodium  combines 
with  almost  all  the  metals ;  and,  in  small 
quantity,  melted  with  steel,  it  has  been 
supposed  to  improve  the  hardness,  close- 
ness, and  toughness  of  this  metal.  Its 
chief  use  at  present  is  for  making  the 
inalterable  nibs  of  the  so-named  rhodium 
pens. 

RHUBARB.  The  root  of  the  Rheum 
pahnatwm,  and  perhaps  some  other  spe- 
cies, cultivated  in  China  for  the  supply  of 
tho  drug  market.    The  varieties  of  rhu- 


barb known  in  commerce  under  the 
names  of  Russian,  Turkey,  and  Indian 
I  rhubarb,  are  all  derived  from  one  source; 
but  the  select  pieces  are  sold  under  the 
name  of  Russian  and  Turkey  rhubarb, 
and  those  of  somewhat  inferior  quality  as 
East  Indian.  To  judge  of  the  quality  of 
rhubarb,  it  should  be  cut  or  broken ; 
when  good  it  is  of  a  mottled  reddish  or 
brownish  red  color ;  that  which  is  very 
pale  or  very  dark  colored,  and  either  so 
soft  as  to  be  spongy,  or  hard  and  stony  in 
texture,  is  bad.  Rhubarb  is  a  valuable 
article  of  the  materia  medica,  being  an 
aperient,  and  at  the  same  time  a  tonic 
and  astringent. 

There  is  a  coloring  matter  (erythrosc) 
obtainable  from  the  rhubarb  root,  by  di- 
gesting it  in  strong  nitric  acid,  and  re- 
moving the  insoluble  yellow  powder. 
This  powder  forms  beautiful  red  solu- 
tions with  potass  and  ammonia :  which 
are  capable  of  being  used  as  a  dye  on 
stuffs.  Its  nature  has  not  been  fully  exa- 
mined. 

RICE.  The  name  by  which  rice  was 
known  to  the  ancient  Greeks  and  Ro- 
mans was  oryza,  and  has  been  adopt- 
ed by  modern  botanists  as  the  generic 
name  of  the  plant  yielding  that  invalua- 
ble grain.  The  genus  oryza  belongs  to 
the  class  liexandria,  order  dygynia  ;  and 
has  ten  glumes  to  a  single  flower,  and 
two  palea,  nearly  equal,  adhering  to  tho 
seed.  It  affords'many  varieties,  of  which 
the  most  common  is  the  oryza  sativa,  or 
the  English  rice.  This  plant  is  raised  in 
immense  quantities  in  India,  China,  and 
most  eastern  countries  ;  in  the  West  In- 
dies, Central  America,  and  the  United 
States,  and  in  some  of  the  southern 
countries  of  Europe.  It,  in  fact,  occupies 
the  same  place  in  most  intertropical  re- 
gions as  wheat  in  the  warmer  parts  of 
Europe,  and  oats  and  rye  in  those  more 
to  the  north.  Forming,  as  it  does,  the 
principal  part  of  the  food,  of  the  most  ci- 
vilized and  populous  eastern  nations,  it 
is  more  extensively  consumed  than  any 
other  species  of  grain.  It  is  light  and 
wholesome,  but  it  is  said  to  contain  less 
of  the  nutritive  principle  than  wheat. 
When  rough,  or  in  its  natural  state  in 
the  husk,  it  is  called  paddy.  There  is  an 
immense  variety  in  the  qualities  of  rice. 
That  which  is  principally  exported  from 
Bengal  has  received  the  name  of  cargo 
rice.  It  is  of  a  coarse  reddish  cast,  but 
is  sweet  and  large-grained,  and  is  pre- 
ferred by  the  natives  to  every  other  sort. 
It  is  not  kiln-dried,  but  is  parboiled  in 
earthen  pots  or  caldrons,    partly  to  de- 


532 


CYCLOPEDIA    OP    THE    USEFUL    ARTS. 


[ric 


stroy  the  vegetative  principle,  so  that  it 
may  keep  better,  and  partly  to  facilitate 
the  process  of  husking.  Patna  rice  is 
moi  s  esteemed  in  Europe  than  any  other 
sort  of  rice  imported  from  the  East.  It 
is  small-grained,  rather  long  and  wiry, 
and  remarkably  white.  But  the  rice 
raised  on  the  low  marshy  grounds  of 
Carolina  is  unquestionably  very  superior 
to  any  brought  from  any  part  of  India. 

The  produce  of  lands  naturally  or  arti- 
ficially irrigated  is,  as  far  as  rice  is  con- 
cerned, from  five  to  ten  times  greater 
than  that  of  dry  land  having  no  com- 
mand of  water ;  and  hence  the  vast  im- 
portance of  irrigation  in  all  countries 
w,here  this  grain  is  cultivated.  But  it  is 
worthy  of  remark,  that  owing  to  the  not 
unfrequent  occurrence  of  severe  droughts, 
there  is  a  greater  variation  in  the  crops 
of  rice  than  in  those  of  any  other  species 
of  grain.  Those  who,  like  the  Hindoos, 
depend  almost  entirely  on  it  for  subsist- 
ence, are  consequently  placed  in  a  very 
precarious  situation.  There  can  be  no 
doubt  that  famines  are  at  once  more  fre- 
q  uent  and  severe  in  Hindostan  than  in 
any  other  quarter. 

A  few  years  ago,  England  was  princi- 
pally supplied  with  cleaned  rice  from 
Carolina.  To  that  country  the  exports 
of  Carolina  rice  have  been  much  re- 
duced. An  improved  method  of  sepa- 
rating the  husk,  which  throws  out  the 
grain  clean  and  unbroken,  has  recently 
been  practised  in  England ;  and  as  the 
grain  when  in  the  husk  is  found  to  pre- 
serve its  flavor  and  sweetness  better  dur- 
ing a  long  voyage  than  when  shelled, 
large  quantities  are  now  imported  rough 
from  Bengal  and  the  United  States. 

The  rice  of  Carolina,  analyzed  by 
Braconnot,  was  found  to  be  composed  of 
starch  85-07,  of  gluten  3-60,  of  gum  0-71, 
of  uncrystallizable  sugar  0*29,  of  a  color- 
less rancid  fat  like  suet  0'13,  of  vegeta- 
ble fibre  4-8,  of  salts  with  potash  and 
lime  bases  0*4,  and  5*0  of  water. 

The  plant,  in  a  wild  state,  has  been 
found  growing  in  the  Northwest  ter- 
ritory :  in  all  that  country  the  wild  rice 
is  found  growing  in  the  lakes  and 
streams. 

Some  of  the  seed  of  this  indigenous 
plant  was  distributed  in  in  1849.  It  has 
been  furnished  by  Professor  Bandall,  of 
Cincinnati,  who  has  lately  come  from 
the  Minnesota  territory. 

It  is  considered  by  him  superior  in 
taste,  and  far  more  nutritious  than  the 
southern  rice ;  it  grows  abundantly  as 
an  indigenous   production,  and  can  be 


cultivated  to  almost  any  extent  in  the 
rivers  and  lakes  that  abound  in  that 
territory.  After  the  rice  is  ready  for 
gathering,  the  tops  are  tied  up  in  small 
sheafs  as  it  stands  growing  in  the  water, 
and  then  the  Indian  in  his  canoe  passes 
through  it  and  beats  off  the  seed  into 
his  canoe,  by  bending  over  the  canoe  the 
tops  so  that  the  seed  may  fall  aright. 
An  Indian  squaw  will  gather  from  five 
to  ten  bushels  per  day.  It  will  grow  in 
water,  we  are  informed,  from  six  inches 
to  five  feet  deep,  when  it  finds  a  muddy 
soil.  Its  stalk,  and  the  branches  or  ears 
that  have  the  seed,  are  described  as  re- 
sembling oats,  both  in  appearance  and 
manner  of  growing,  the  stalks  being  full 
of  joints  and  rising  from  one  half  to  four 
feet  above  the  level  of  the  water. 

Professor  Bandall  is  inclined  to  think 
that  there  is  as  much  rice  land  water 
in  Minnesota  as  in  the  same  area  of  the 
States  of  South  Carolina  and  Georgia, 
and  that  the  Minnesota  rice  ground  pro- 
duces as  much  to  the  acre,  and  will  at 
no  distant  period  compete  with  the 
southern  production.  We  have  tried  it 
boiled  as  usual,  and  have  found  it  very 
palatable. 

The  specimen,  however,  in  appear- 
ance, is  not  inviting,  as  the  outer  skin 
of  the  hulled  rice  is  dark  colored,  though 
the  inside  is  white  as  the  southern  kind. 
This  may  be  owing  to  some  difficulty  in 
preserving  it,  and  probably  if  more  com- 
pletely hulled  the  objection  would  dis- 
appear. 

Since  the  notice  made  of  it  by  Mr. 
Bandall,  it  has  been  further  noticed  as 
abundant  in  the  Minnesota  territory. 
Gen.  Verplanck,  late  Commissioner  to 
the  Chippewa  Indians,  pronounces  it 
better  than  southern  rice.  The  kernels 
are  larger  and  its  flavor  is  better;  for 
when  boiled  and  stewed,  and  left  to  cool, 
it  forms  a  consistent  mass  like  good 
wheat  bread,  and  more  nutritious.  It 
is  stated  that  very  great  quantities  grow 
on  all  the  lakes. in  this  northern  country. 
The  outlets  and  bays  are  filled  with  it. 
It  ripens  in  the  month  of  August,  and  is 
the  main  reliance  of  the  Indians,  during 
the  winter  months,  for  their  sustenance. 
From  this  account  it  would  seem  that  it 
might  be  an  article  worthy  of  attention, 
and  that  possibly  it  may  become  known 
and  used  in  the  more  eastern  states. 

The  introduction  of  rice  in  this  coun- 
try is  said  to  have  been  owing  to  one  of 
those  trivial  occurrences  which  often  ex- 
ert a  powerful  influence  on  a  notion's 
prosperity.    It  is  stated  that  in  the  year 


rifJ 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


533 


1695,  a  brig  from  Madagascar,  touching 
at  Charleston  on  her  way  to  England, 
anchored  off  Sullivan's  Island.  The  cap- 
tain invited  Landgrave  Smith  on  hoard, 
and  presented  to  him  a  bag  of  seed  rice, 
with  information  of  its  growth  in  the 
east,  and  its  excellence  for  food  and  its 
amazing  increase.  The  governor  divided 
it  among  his  friends,  who  made  experi- 
ments with  it,  which  fully  answered  ex- 
pectation, and  from  this  small  beginning 
arose  one  of  the  great  staple  articles  of 
South  Carolina  and  Georgia. 

The  quantity  of  rice  raised  in  1847, 
amounted  to  103,640,590  lbs.,  the  greater 
part  of  which  was  grawa  in  South  Caro- 
lina :  the  value  of  the  foregoing  quantity 
was  $3,091,215. 

The  exports  of  rice  from  this  country, 
during  1847  and  1848,  were  tc  the  value 
of— 

1847 $3,605,896 

1848 2,331.824 

A  rice  crop  is  said  in  produce  to  equal 
Bix  times  the  wheat  crop  in  the  same  lo- 
cality. Forty  bushels  per  acre,  however, 
appear  to  be  the  usual  crop  :  it  requires 
a  warm  and  wet  soil,  hence  it  is  so  Dene- 
fited  by  irrigation. 

The  mode  of  irrigation  of  rice  in  China 
is  thus  described  in  Fortune's  China,  a 
work  which  contains  many  interesting 
particulars  relating  to  Chinese  agricul- 
ture : — 

"Irrigation  in  China. — Kice  is  grown 
on  the  lower  terrace  ground;  and  a 
stream  of  water  is  always  led  from  some 
ravine  and  made  to  flow  across  the  sides 
of  the  hills,  until  it  reaches  the  highest 
terrace,  into  which  it  flows,  and  floods 
the  whole  of  the  level  space.  When  the 
water  rises  three  or  four  inches  in  height, 
which  is  sufficiently  high  for  the  rice,  it 
finds  vent  at  an  opening  made  for  the 
purpose  in  the  bank,  through  which  it 
flows  into  the  terrace  below,  which  it 
floods  in  the  same  manner,  and  soon  to 
the  lowest.  In  this  way  the  whole  of 
the  rice  terraces  are  kept  flooded  conti- 
nually, until  the  stalks  of  the  crops 
assume  a  yellow  ripening  hue  ;  when  the 
water  being  no  longer  required,  is  turned 
back  into  its  natural  channel,  or  led  to 
a  different  part  of  the  hill  for  the 
nourishment  of  other  crops.  These 
mountain  streams,  which  abound  in  all  ! 
parts  of  the  hilly  districts,  are  of  the  I 
greatest  importance  to  the  farmer;  and  ! 
as  they  generally  spring  from  a  high  J 
elevation   in   the   ravines,    they  can  ho 


conducted  at  pleasure  over  all  the  lower 
parts  of  the  hill.  No  operation  in  agri- 
culture gives  him  and  his  laborers  more 
pleasure  than  leading  these  streams  of 
water  from  one  place  to  another,  and 
making  them  subservient  to  their  pur- 
poses. In  my  travels  in  the  country  the 
inhabitants  often  called  my  attention  to 
this  branch  of  their  operations  ;  and  I 
pleased  them  much  when  I  expressed 
my  admiration  at  the  skill  with  which 
they  executed  it.  The  practice  is  not 
confined  to  the  paddy-fields ;  for  I  re- 
member once,  when  superintending  the 
planting  of  some  large  trees  and  shrubs 
in  the  garden  of  Messrs.  Dent  and  Co., 
in  Hong-Kong,  after  I  had  given  them 
a  large  supply  of  water  at  the  time  they 
were  put  into  the  ground,  I  desired  the 
gardener  to  repeat  "the  dose  next  morn- 
ing. But  on  the  following  day,  when  I 
returned  to  the  spot,  I  was  surprised  to 
find  a  little  stream  divided  into  many 
branches,  and  meandering  among  the 
roots  of  the  newly-planted  trees.  As 
there  was  no  stream  there  before,  I  went 
to  examine  its  source,  and  found  that  it 
had  been  led  from  a  neighboring  ravine 
— a  work  more  easy  than  carrying  a  larsre 
supply  of  water  in  buckets,  at  the  same 
time  more  effectual." 

RICE  PAPEK.  This  substance  is  said 
to  be  a  membrane  of  the  Artocarjnis  in- 
cisa,  or  bread-fruit  tree.  It  is  brought 
from  China  in  small  pieces,  dyed  of  vari- 
ous colors,  and  is  used  as  a  material  for 
painting  upon,  and  for  the  manufacture 
of  several  fancy  and  ornamental  articles. 
It  is  sometimes  erroneously  stated  to  be 
prepared  from  rice. 

RIFLE  GUNS.  Muskets  or  pieces  of 
ordnance,  whose  barrels,  instead  of  being 
a  clear  cylinder  inside,  are  furrowed  with 
spiral  channels.  The  object  is  to  give 
the  ball  a  rotatory  motion  about  an  axis, 
in  consequence  of  which  it  preserves  its 
direction  with  much  greater  certainty 
than  when  fired  from  the  common  clear 
barrel.     (See  Gun.) 

Prussian  Breech- Loading  Rifle.  There 
is  a  Prussian  rifle,  known  by  the  name 
of  the  Zund  Nadel  (darting  needle).  The 
light  infantry  of  the  Prussian  army  are 
all  armed  with  this  fearful  weapon,  and 
in  the  late  war  with  the  Danes,  and  in 
some  encounters  with  the  people,  it 
proved  terribly  advantageous  on  the  side 
of  Prussia.  It  has  a  number  of  points 
about  it,  very  different  from  all  other 
breech-loading  fire-arms,  the  principal  of 
which  are  the  three  following.  First,  it 
uses  a  different  cartridge  and  no  detonat- 


S34 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[roa 


ing  powder,  but  a  friction  needle — darting 
needle  (zund  nadel),  which  pierces  the 
bottom  of  the  cartridge  and  ignites  the 
powder  by  a  friction  combustible  prim- 
ing. All  this  is  done  inside,  and  it  is 
certainly  as  efficacious  in  wet  as  in  dry 
weather.  Second,  An  air  chamber  be- 
hind the  cartridge,  in  which  the  expand- 
ed air  acts  to  force  out  the  ball.  It  carries 
a  ball  800  yards,  and  is  as  effective  at  that 
distance  as  a  musket  at  150,  and  in  that 
case,  for  picking  off  artillerymen  on  the 
field,  it  was  said  by  a  celebrated  Ameri- 
can General,  who  beheld  its  effects, 
u  their  occupation  's  gone."  Third,  The 
sliding  breechpin,  and  the  manner  of 
operating  and  fastening  it  in  an  inclined 
butt  of  the  breech. 

RIGIDITY.  In  mechanics,  a  resist- 
ance to  change  of  form.  In  all  theoretical 
investigations  respecting  the  application 
of  forces  through  the  intervention  of 
machines,  those  machines  are  assumed 
(except  cords)  to  be  perfectly  rigid,  so 
far  as  the  forces  employed  are  able 
to  affect  their  integrity  of  form  and 
structure.  Rigidity  is  often,  in  the  arts, 
called  stiffness,  and  is  opposed  to  flexi- 
bility. 

M  77ie  rigidity  of  cords,  or  the  difficulty 
with  which  they  are  bent  into  any  given 
curve,  is  the  chief  cause  of  the  loss  of  power 
arising  from  their  employment  in  ma- 
chines. The  law  of  their  loss  of  force 
may  be  thus  expressed :  The  resistance 
arising  from  the  stiffness  of  cords  is  as 
the  weights  which  stretch  the  cords  mul- 
tiplied by  the  thickness  of  the  cords,  and 
divided  by  the  radii  of  curvature  of  the 
surfaces  over  which  they  pass.  It  is 
however,  necessary  to  state,  that  experi- 
ments exhibit  great  discrepancies  with 
this  theoretical  law. 

RINGS,  FAIRY.  This  name  is  given 
to  irregular  circles  in  pastures  and  lawns 
on  which  Agarics  spring  up,  and  which 
become  much  more  verdant  than  the 
surrounding  grass.  They  are  caused  by 
the  centrifugal  growth  of  the  spawn  of 
the  Agaric,  which  radiates  from  a  com- 
mon centre,  and  bears  the  fructification, 
which  is  what  appears  above  ground, 
only  at  the  circumference.  The  verdure 
of  the  grass  where  these  fungi  grow 
seems  to  be  caused  either  by  their  ma- 
nuring the  ground  when  they  decay,  or 
by  the  nitrogen  they  give  off,  which  is 
aii  active  stimulant  to  vegetation.  The 
implication  of  fairy  rings  was  given  to 
this  phenomenon  from  their  being  re- 
garded as  the  places  where  the  fairies 
held  their  nocturnal  revels. 


ROADS,  are  pathways  formed  through 
a  country,  by  which  passengers  and  com- 
modities may  travel,  or  be  transported, 
with  more  or  less  facility  and  expedition, 
from  one  place  to  another.  Roads  are  of 
various  kinds,  according  to  the  state  of 
civilization  and  wealth  of  the  country 
through  which  they  are  constructed,  and 
according  to  the  nature  and  extent  of  the 
traffic  to  be  carried  on  upon  them,  from 
the  rude  paths  of  the  aboriginal  people, 
carried  in  direct  lines  over  the  natural 
surface  of  the  country,  passable  only  by 
foot  passengers  or  pack-horses,  to  the 
comparatively  perfect  modern  road,  car- 
ried on  an  artificial  causeway,  and  re- 
duced to  a  nearly  level  surface  at  enor- 
mous expense  by  means  of  vast  excava- 
tions, extensive  embankments,  bridges, 
viaducts,  tunnels,  and  other  expedients 
supplied  by  the  skill  and  ingenuity  of 
the  civil  engineer. 

Advantages  of  Roads. — There  is  no  ex- 
pedient which  'more  powerfully  conduces 
to  the  advancement  of  a  people  in  civiliza- 
tion, or  to  the  extension  of  their  pros- 
perity and  national  wealth,  than  the  con- 
struction of  good  roads,  connecting  the 
various  centres  of  commerce  and  of  in- 
dustry about  which  they  may  have  col- 
lected themselves.  The  invention  of 
printing,  the  expedient  of  money,  the 
adoption  of  a  uniform  system  of  weights 
and  measures,  would  severally  be  ineffec- 
tual, or  productive  of  advantages  of  a 
very  limited  extent,  if  the  intercommu- 
nication of  those  whose  feelings  and  ideas 
are  expressed  and  conveyed  in  print, 
and  among  whom  money  is  made  to  cir- 
culate, and  whose  commerce  is  stimulat- 
ed and.  facilitated  by  the  uniform  module 
of  quantity  supplied  by  weights  and 
measures,  were  not  facilitated  and  expe- 
dited by  the  means  of  conveyance  sup- 
plied by  roads.  Without  raids,  the  in- 
terchange of  advantages,  moral,  intellec- 
tual, and  physical,  which  now  takes  place 
in  all  highly  civilized  countries  between 


urbane   population, 
with( 


the  rural  and  the 
I  could  not  be  maintained ;  without  them, 
I  indeed,  large  towns  or  cities  could  not 
I  continue  to  exist.  The  supply  of  the 
j  population  collected  in  such  places,  with 
I  the  various  products  of  agriculture,  ne- 
:  cessary  to  their  physical  existence,  could 
I  not  be  sustained.  Nor,  on  the  other 
j  hand,  would  the  rural  population  afford- 
i  ing  that  supply  be  benefited  by  a  return 
|  in  exchange  of  the  refinements  of  the 
|  town,  and  the  various  articles  of  luxury 
j  and  necessity  obtained  by  commerce  from 
I  every  part  of  the  globe. 


roa] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


535 


But  roads  are  not  less  necessary  for  the 
advancement  of  agriculture  itself,  than 
for  the  due  maintenance  of  the  necessary 
relations  between  the  towns  and  the 
country.  Without  the  aid  of  roads,  it 
would  be  impossible  to  apply  those  arts  to 
the  soil  by  which  increased  powers  of 
production  are  given  to  it.  Without  roads, 
the  various  kinds  of  manure,  by  which 
the  scientific  farmer  knows  how  to  raise 
augmented  crops,  could  not  be  trans- 
ported to  his  fields  from  the  place,  often 
distant  and  difficult  of  access,  where  such 
manures  are  found.  Roads  may  then,  in 
fact,  be  considered  as  a  system*  of  veins 
and  arteries,  by  which  all  those  princi- 
ples necessary  for  the  maintenance  of  the 
prosperity  of  a  country  are  kept  in  circu- 
lation. 

The  Art  of  Road-making. — When  it  is 
proposed  to  construct  a  line  of  road  ex- 
tending between  two  places,  the  engineer 
upon  whom  such  a  duty  devolves,  first 
makes  himself  well  acquainted  with  the 
surface  of  the  country  lying  between  the 
two  places,  so  as  to  obtain  an  acquaint- 
ance with  the  face  of  the  country,  some- 
what approaching  to  that  which  would 
be  supplied  by  a  superficial  model  of  it, 
which  would  exhibit  all  its  inequalities 
and  undulations  of  surface.  He  is  then 
to  select  what  he  considers,  all  circum- 
stances being  taken  into  account,  the  best 
general  route  for  the  proposed  road. 
But,  previously  to  laying  it  out  with  ac- 
curacy, it  is  necessary  to  make  an  instru- 
mental survey  of  the  country  along  the 
route  thus  selected;  taking  the  levels 
from  point  to  point  throughout  the  whole 
distance,  and  making  borings  in  all  places 
where  excavations  are  required,  to  deter- 
mine the  strata  through  which  such  cut- 
tings are  to  be  carried,  and  the  requisite 
inclinations  of  the  slopes  or  slanting 
sides,  as  well  of  the  cuttings  as  of  the 
embankments  to  be  formed  by  the  mate- 
rial thus  obtained.  It  is  also  requisite,  in 
the  selection  of  the  route  for  the  propos- 
ed road,  to  have  regard  to  the  supply  of 
materials,  not  only  for  first  constructing  it, 
but  for  maintaining  it  in  repair  ;  thus,  the 
position  of  gravel  pits  and  quarries  in  the 
neighborhood  of  the  proposed  line,  and 
the  modes  of  access  to  them,  should  be 
well  ascertained. 

The  results  of  such  an  investigation 
should  be  reduced  to  a  plan  and  section  ; 
the  plan  of  the  road  being  on  a  scale  not 
less  than  66  yards  to  an  inch,  and  the 
section  not  less  than  30  feet  to  an  inch. 

The  loss  of  tractive  power,  and  danger 
to  travellers  produced  by  steep  acclivi- 


ties, render  it  especially  necessary  that  a 
proper  limitation  should  be  imposed  upon 
the  inclinations  or  acclivities  on  every 
line  of  road  on  which  much  traffic  is  car- 
ried on.  As,  however,  this  reduction  of 
hills  in  a  country  where  much  inequality 
of  surface  exists  is  attended  with  a  consid- 
erable outlay  of  capital,  the  engineer  will 
have  to  balance  the  cost  of  constructing 
a  road,  having  the  best  possible  inclina- 
tions against  the  advantages  to  be  ob- 
tained in  the  permanent  working  of  the 
road  ;  and  if  the  expected  traffic  be  not 
such  as  to  yield  advantages  proportionate 
to  the  capital  absorbed,  greater  rates  of 
inclination  must  be  allowed  to  the  hills, 
with  a  view  to  diminish  the  extent  of  the 
works,  and  to  render  the  expense  of  con- 
structing the  road  proportionate  to  the 
traffic  expected  upon  it. 

A  dead  level,  even  where  it  can  be  ob- 
tained, is  not  the  best  course  for  a  road  ; 
a  certain  inclination  of  the  surface  facili- 
tates the  drainage,  and  keeps  the  road  in 
a  dry  state.  There  is  a  certain  inclina- 
tion* depending  on  the  degree  of  perfec- 
tion given  to  the  surface  of  the  road,  and 
on  the  structure  of  the  carriages  worked 
upon  it,  which  cannot  be  exceeded  with- 
out a  direct  loss  of  tractive  power ;  this 
inclination  or  acclivity  is  that,  in  descend- 
ing which,  at  a  uniform  speed,  the  traces 
slacken,  or  which  causes  the  carriages  to 
press  on  the  horses :  the  limiting  incli- 
nation within  which  this  effect  does  not 
take  place  is  called  the  angle  of  repose. 

On  all  acclivities  less  steep  than  the 
angle  of  repose,  a  certain  amount  of  trac- 
tive force  is  necessary  in  the  descent  as 
well  as  in  the  ascent ;  and  the  mean  of 
the  two  drawing  forces,  ascending  and 
descending,  is  equal  to  the  force  along  a 
level  road.  Thus,  on  such  acclivities  as 
much  power  is  gained  in  the  descent  as 
is  lost  in  the  ascent;  but  on  acclivities 
which  are  more  steep  than  the  angle  of 
repose,  the  load  presses  on  the  horses 
during  their  descent,  so  as  to  impede  their 
action,  and  their  power  is  expended  in 
checking  the  descent  of  the  load  :  or,  if 
this  effect  be  prevented  by  the  use  of  any 
form  of  drag  or  break,  then  the  power 
expended  on  such  drag  or  break  corre- 
sponds to  an  equal  quantity  of  mechani- 
cal power  expended  in  the  ascent,  for 
which  no  equivalent  is  obtained  in  the 
descent. 

On  Avell-constructed  roads,  with  car- 
riages such  as  now  are  generally  used  in 
England,  the  angle  of  repose  may  be 
taken  at  about  one  in  thirty-six:  and 
this  is  consequently  an  acclivity  which 


536 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


ought  not  to  be  exceeded  on  roads  over 
which  much  traffic  is  carried. 

The  expedients  by  which  the  requisite 
inclinations  are  obtained  on  common 
roads  are  the  same  as  those  which  are  re- 
sorted to  in  the  construction  of  railways. 
(See  Railboads.) 

The  exact  course  of  the  road,  and  the 
degree  of  its  acclivities  being  determined, 
the  next  thing  to  be  considered  is  the 
formation  of  its  surface.  The  qualities 
which  ought  to  be  imparted  to  it  are  two- 
fold— first,  it  should  be  smooth  ;  second- 
ly, it  should  be  hard;  and  the  goodness 
of  the  road  will  be  exactly  in  the  propor- 
tion of  the  degree  in  which  these  quali- 
ties can  be  imparted  to  it,  and  perma- 
nently maintained  upon  it.  An  error  pre- 
vailed among  road  engineers  until  a  very 
recent  period.  It  was  considered  that 
smoothness  of  surface  alone  was  sufficient 
for  the  perfection  of  a  road;  and  that, 
provded  it  could  be  made  sufficiently 
durable,  it  was  unimportant  how  soft  or 
yielding  the  coating  of  the  road  might 
be.  This  error,  into  which,  among  others, 
Macadam  himself  fell,  Avas  based  upon  a 
neglect  of  one  of  the  most  important 
circumstances  to  be  considered  in  the 
construction  of  a  road.  The  main  object 
to  be  attained  by  all  roads  is  the  diminu- 
tion of  the  resistance  which  a  carriage 
opposes  to  the  tractive  power.  Other 
things  being  the  same,  it  was  sufficiently 
apparent  that  this  resistance  would  be 
diminished  by  increasing  the  smoothness 
of  the  road  surface.  But  roughness  or 
unevenness  of  surface  is  not  the  only 
cause  of  resistance  to  the  tractive  power; 
if  two  roads  have  their  surfaces  equally 
smooth  and  even,  but  one  is  soft  and 
elastic,  so  as  to  yield  under  the  pressure 
of  the  wheel,  recovering  its  form  as  the 
wheel  advances,  and  the  other  is  hard 
and  unyielding,  the  resistance  to  the 
tractive  power  will  be  greater  on  the  soft 
and  yielding  road  than  on  the  hard  and 
unyielding  road  ;  and  this  augmentation 
of  resistance  will  be  in  proportion  to  the 
softness  of  the  surface.  That  this  would 
be  the  case,  admits  of  immediate  demon- 
stration on  mechanic.il  and  mathematical 
principles ;  but,  without  resorting  to 
these,  it  must  be  sufficiently  apparent 
from  the  results  of  the  most  common  ex- 
perience. A  surface  of  velvet  may  be  as 
smooth  and  even  as  a  surface  of  ice  ;  but 
if  an  ivory  ball  be  rolled  on  the  latter,  it 
will  continue  its  motion  much  longer  than 
on  the  former.  In  fact,  the  wheels  of  a 
carriage  in  passing  along  a  soft  road  sink 
into  its  surface,  as  the  ball  would  sink 


into  the  pile  of  the  velvet;  and  although, 
in  virtue  of  its  elasticity,  the  surface  of 
the  road,  like  that  of  the  velvet,  may  re- 
cover its  smoothness  after  the  pressure 
has  been  removed  from  it,  still  a  resist- 
ance will  be  offered  to  the  drawing  or  im- 
Selling  power,  which  would  not  be  pro- 
uced  by  a  hard  and  unyielding  surface 
equally  smooth. 

Macadamization. — This  process,  which 
has  received  its  name  from  Macadam,  to 
whose  labors  the  improvement  of  the 
roads  of  England  within  the  last  half  cen- 
tury owes  so  much,  consists  in  forming 
the  road  crust  of  stones,  broken  with  a 
hammer  into  angular  pieces  of  a  small 
and  uniform  size.  This  method,  how- 
ever, is  one  which  was  long  practised  in 
various  parts  of  Europe.  When  the 
stones  of  which  the  road  crust  is  to  be 
formed  are  broken  to  the  proper  magni- 
tude and  form,  they  are  spread  over  the 
surface  of  the  road  in  a  layer  of  three  or 
four  inches  thick.  After  this  has  been 
consolidated  by  carriages  working  upon 
it  or  by  rollers,  another  layer  of  broken 
stones  of  equal  depth  is  laid  upon  it;  it 
is  consolidated  in  like  manner ;  and  thus 
one  layer  is  laid  over  another  until  an 
artificial  crust  is  formed  of  broken  stones 
of  sufficient  thickness  to  give  the  requi- 
site strength  to  the  road. 

A  coating  or  road  crust  thus  formed 
might  be  constructed  on  any  substratum 
whatsoever,  and  a  smooth  and  apparent- 
ly good  road  would  be  obtained.  It  was 
the  practice  of  Mr.  Macadam  to  disregard 
the  nature  of  the  substratum ;  and  ho 
maintained  that  if  it  was  not  such  a  bog 
as  would  not  allow  a  man  to  walk  over  it, 
he  would  even  prefer  it  to  a  hard  bottom. 

Telford's  System. — The  improvement 
in  road-making,  which  consists  in  a  due 
attention  to  the  substratum  or  foundation 
of  the  road,  so  as  to  give  increased  facili- 
ty to  the  tractive  power  by  rendering  its 
surface  hard  and  unyielding,  is  due  to 
the  late  Mr.  Telford.  The  following  is  a 
description  of  the  method  of  constructing 
such  a  road  practised  by  that  eminent 
engineer. 

Upon  the  level  bed,  prepared  for  the 
road  materials,  a  bottom  course  or  layer 
of  stones  is  to  be  set  by  hand,  in  form  of 
a  close  firm  pavement.  The  stones  set 
in  the  middle  of  the  road  should  be  7  in- 
ches in  depth ;  at  9  feet  from  the  centre 
the  depth  should  be  5  inches;  at  12  feet, 
4  inches :  and  at  15  feet,  8  inches ;  the 
entire  width  of  the  road  being  30  feet. 
These  stones  are  to  be  set  on  their  broad- 
est edges  lengthwise  across    the  road, 


boa] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


537 


and  the  breadth  of  the  upper  edge  should 
not  exceed  4  inches.  Ail  the  irregulari- 
ties of  the  upper  part  of  this  pavement 
are  to  be  broken  off  by  hammers,  and  all 
the  interstices  to  be  filled  with  stone 
chips  firmly  wedged  or  packed  by  hand 
with  alight  hammer*  so  that,  when  the 
pavement  is  finished,  its  cross  section 
shall  have  a  convexity  of  surface  of  about 
4  inches  in  the  centre  above  the  extreme 
edges  ;  18  feet  in  the  centre  of  this  pave- 
ment are  to  be  coated  with  a  layer  of  hard 
broken  stones,  6  inches  deep ;  of  these  6 
inches,  4  must  be  first  put  on  and  worked 
down  by  carriages  and  horses  in  the  or- 
dinary "traffic  of  the  road,  care  being 
taken  constantly  to  rake  in  the  ruts  until 
the  surface  has  become  firm  and  the  crust 
consolidated.  After  this,  the  remaining 
2  inches  of  stone  may  be  put  on :  the 
whole  of  this  stone,  forming  6  inches  of 
crust,  is  to  consist  of  pieces  broken  as 
nearly  as  is  practicable  into  a  cubical 
form,  and  of  such  a  magnitude  that  they 
can  pass  through  a  ring  of  2k  inches  in- 
ternal diameter.  The  spaces  on  each 
side  of  the  middle  18  feet  are  to  be  coated 
with  broken  stone  or  well-cleansed  stone 
gravel  up  to  the  level  of  the  footpath,  or 
other  boundary  of  the  road,  so  as  to  make 
the  whole  convexity  of  the  road  6  inches 
in  the  middle  above  the  level  of  the  edges ; 
and  the  whole  of  the  materials  thus 
formed  and  consolidated,  should  be  cov- 
ered with  a  coating  1£  inches  deep  of 
good  gravel,  free  from  clay  or  earth. 

Under  the  article  Pavement  for  roads, 
the  Russ  and  Perrine  pavements  put 
down  in  New-York  are  described.  These 
are  in  part  based  on  Telford's  plan,  and 
are  enduring  roads.  In  1850,  a  part  of 
Broadway  was  paved  thus  :  there  was  an 
excavation  made  to  the  depth  of  2  feet, 
and  coarse  flagstone  2  feet  by  3  laid 
down.  The  seams  were  filled  in  by  hot 
pitch  covered  by  gravel,  and  above  this 
a  layer  of  broken  road  metal  was  laid 
smoothly,  and  the  whole  overtopped  with 
large  granite  blocks,  about  the  size  used 
for  Russ  pavement.  There  can  be  no 
question  about  the  enduring  qualities  of 
this  pavement,  but  the  large  blocks  on 
top  are  objectionable,  for  when  worn 
smooth  they  become  dangerously  slippe- 
ry. Neither  is  it  convenient,  when  a  ne- 
cessity arises  to  open  the  street  to  get  at 
the  gas  or  water  pipes.  Top  blocks  of  half 
the  size  would  answer  a  better  purpose ; 
where  a  firm  foundation  is  used  the  top 
tier  need  not  be  so  large.  On  these  roads 
the  superficial  wear  Is  but  slight,  and 
much  of  the  dust  of  summer  and  mud  of 

28* 


winter  is  obviated.  Such  is  the  structure 
which  is  requisite  for  the  streets  which 
are  the  main  thoroughfares  of  a  great 
city ;  a  pavement  with  less  strength  of 
foundation,  and  formed  of  smaller  blocks 
of  stone,  being  used  for  the  streets  of 
less  intercourse. 

To  many  inconveniences  produced  in 
the  great  thoroughfarea  of  this  or  any 
other  large  city,  along  which  heavy 
stages  travel,  by  reason  of  the  rapid 
wear  of  every  kind  of  pavement  hitherto 
adopted,  a  suspension  of  the  intercourse 
during  the  frequent  repairs,  the  dust  in 
summer  and  the  mud  in  winter,  pro- 
duced by  a  surface  of  broken  stones, 
and  the  intolerable  noise  produced 
by  every  species  of  stone  pavement, 
have  lately  e.xcited  much  inquiry  as  to 
the  possibility  of  constructing  some  road 
having  sufficient  strength  for  a  traffic  so 
enormous,  sufficient  durability  to  prevent 
the  inconvenience  of  the  frequent  sus- 
pension of  intercourse  by  the  necessity  of 
repairs,  and  presenting  a  surface  which, 
while  it  would  be  free  from  the  noise  of 
a  stone  pavement,  would  not  be  attended 
with  the  inconvenience  of  dust  and  mud 
produced  by  a  surface  of  broken  stone. 
This  problem  appears  to  be  in  a  great  de- 
gree solved  by  the  adoption  of  a  pave- 
ment of  wood.  A  short  piece  of  Oxford 
Street,  London,  was  paved  in  the  begin- 
ning of  1839  ;  and  after  a  successful  trial  of 
several  months,  the  same  pavement  was 
extended  nearly  throughout  the  whole 
extent  of  that  street;  and  up  to  the  year 
1846,  this  method  of  pavement  was 
in  process  of  construction  in  several 
other  thoroughfares  of  London.  The 
idea  of  a  wooden  pavement  is  not  new. 
In  the  northern  parts  of  Germany  and  in 
Russia  such  pavements  have  been  long 
in  use ;  some  of  the  main  streets  of 
Petersburg!!  and  Vienna  have  long  been 
paved  in  this  manner.  A  few  years  ago 
a  series  of  experiments  were  made  at  New 
York,  to  determine  the  best  description 
of  paving  for  a  street.  One  of  the  method* 
adopted  was  a  tesselated  pavement,  form- 
ed of  hexagonal  b!ocks  of  pine  wood, 
measuring  6  inches  on  each  side  of  their 
transverse  section,  and  12  inches  in  depth. 
From  the  manner  in  which  the  timber  is 
cut,  its  fibres  are  vertical,  and  therefore 
the  tendency  to  wear  from  vertical  pres- 
sure is  small.  The  blocks  are  coated 
with  pitch  or  tar,  forming  a  smooth  upper 
surface. 

Various  methods  have  been  proposed 
for  laying  the  wood  pavements  of  Lon- 
don ;   but  as  these  methods  have  been 


538 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[roa 


tried  and  found  objectionable,  it  is  un- 
necessary to  do  more  than  notice  them 
here.  There  appears,  however,  still 
sufficient  to  justify  a  well-grounded  ex- 
pectation that  wood  pavements  of  some 
iorm  or  other  will  soon  supersede  all 
others  for  great  thoroughfares  of  towns. 

In  constructing  roads  it  is  far  better  to 
make  them  as  level  as  possible  at  first, 
and  rather  go  round  than  up  the  hills, 
it  is  calculated  that  the  power  of  a  horse, 
>n  a  level,  averages  1,000  lbs.,  at  a  mod- 
irate  pace,  and  in  a  rise  of  1  in  100  feet 
he  can  draw  only  900  ;  1  in  50,  810 ;  1  in 
44,  750 ;  1  in  40,"  720 ;  1  in  30,  640  ;  1  in 
26,  540  ;  1  in  24,  500  ;  1  in  20,  400;  1  in 
10,  250.  In  round  numbers,  upon  a  slope 
of  1  in  44,  or  120  feet  to  the  mile,  ahorse 
can  draw  only  three-quarters  as  much 
as  lie  can  upon  a  level ;  on  a  slope  of  1  in 
24,  or  220  feet  to  a  mile,  he  can  draw 
only  half  as  much  ;  and  on  a  slope  of  1  in 
10,  or  528  feet  to  the  mile,  only  one-quar- 
ter as  much.  Though  a  horse  on  a  level 
is  as  strong  as  five  men,  yet  on  a  steep 
hill  it  is  less  strong  than  three ;  for  three 
men,  carrying  each  100  lbs.,  will  ascend 
faster  than  a  horse  with  300  lbs.  The 
popular  theory,  that  a  gentle  undulating 
road  is  less  fatiguing  to  horses  than  one 
which  is  perfectly  level,  is  pronounced 
erroneous. 

Mr.  Bevan  has  published  results  of 
some  experiments  on  the  actual  force  of 
draught  of  carriages  upon  common  roads, 
all  made,  or  reduced  to  roads  perfectly 
level  or  horizontal,  to  separate  the  me- 
chanical force  due  to  the  inclination  of 
the  hill  or  plane  from  the  force  necessary 
to  overcome  the  friction  of  the  carriage, 
in  its  ordinary  state,  as  affected  by  the 
condition  of  the  road ;  and,  by  way  of 
rendering  them  comparable  with  other 
experiments,  which  have  been,  or  may 
yet  be,  made  on  this  subject,  he  consid- 
ered the  gross  load  of  the  wagon  and 
burden  to  be  divided  into  1000  parts. 

Loose  sandy  road,  force  of  draught 
204  or  l-5th. 

Turnpike-road,  new  gravelled,  mean 
143  or  l-7th. 

Ordinary  bye-road,  mean  106,  nearly 
l-9*th. 

Hard  compact  loam,  mean  53,  nearly 
l-19th. 

Dry  hard  turf,  mean  40  or  l-25th. 

Turnpike-road,  with  a  little  dirt,  mean 
34i  or  l-29th. 

Turnpike-road,  free  from  dirt,  mean 
80J  or  l-33d. 

From  which  it  appears  that  five  horses 
will  draw  with  equal  ease  the'same  load 


upon  a  good  hard  turnpike-road,  as  thirty' 
three  horses  can  do  upon  loose  sand  !  Or, 
if  we  assume  the  value  of  draught,  upon 
a  well-formed  road  in  good  condition,  at 
sixpence  per  ton  per  mile,  the  equivalent 
price  will  be 

s.  d. 

Upon  hard  turf 0    71 

"     hard  loam 0    9$ 

"     ordinary  bye-road 1    7 

*      newly  gravelled  road 2    2 

"      loose  sandy  road 3    1 

On  hard  smooth  roads  the  forces  are 
required  to  be  as  the  angle  of  inclination, 
nearly ;  but  when  the  wheels  sink,  they 
have  to  overcome  the  enlarged  angle 
created  by  the  cavitv,  in  relation  to  the 
level  ground  which  follows. 

He  has  published  a  table,  containing 
the  results  of  experiments  made  upon 
the  hardness  of  road  materials,  or  their 
power  of  resisting  the  percussion  of  a 
given  weight  of  cast-iron,  falling  a  few 
inches  upon  the  several  specimens"  broken 
to  the  ordinary  size,  and  resting  upon 
stone  or  iron.  Supposing  the  weather  to 
have  no  action,  the  table  would  express 
nearly  the  relative  value  of  the  materials, 
for  the  purpose  of  supporting  the  wear 
of  a  road ;  and,  therefore,  those  which 
resist  the  action  of  frost  and  weather,  and 
have  the  highest  numbers,  are  most  val- 
uable. 

Sienite 100 

White  marble 37-31 

ChdlesexP?!,!,!!'..!V.nCI'.(34'27'    52,56'    S5'65 

Quartz  pebble 70 

Ferruginous  sandstone 20"42 

Hurlock  from  lower  chalk 10 

Chalk 3 

Granite 110 

Flint,  yellow 3326 

Greenstone 110 

Sandstone,  soft 136 

Tile  fragment 20 

Gritstone, near  Brixworth 4860 

Limestone,  near  Bradwall 5 

Dry  clay 12 

Flint,  black 11  30 

Portland  stone,  hard 14 

Quartz,  white 56 

Blue  pebble,  like  Rowley  rag 105110 

Coarse  limestone,  near  Stilton 60 

Gritstone,  near  Leeds 100115 

Yorkshire  paving-stone 20 

Ketton,  hard 20 

Tetternhoe 4 

Chert 57 

Gray  wether,  Herts  and  Wilts 18 

Grit  of  upper  bed,  Collymeston 40 

Second  bed,  ditto 100 

Slate  at  ditto 50 

Stockton  limestone,  (lias) 45 

Newbold,  on  Avon,  ditto 86 

Limestone  of  Stoke  Cruerne 85 

Copper  slag 248 


ROO] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


539 


The  steady  pressure,  without  percus- 
sion, required  to  crush  a  piece  of  the 
marble,  weighing  half  an  oz.,  was  100 
lbs. ;  to  crush  the  grey  flint,  of  1*2  oz. 
weight,  2000  lbs. ;  to  crush  the  rolled 
white  quartz  pebble,  of  2  oz.  weight,  340U 
lbs. 

KOCHELLE  SALT.  The  tartrate  of 
soda  and  potassa.  It  is  a  double  salt,  j 
composed  of  2  equivalents  of  tartaric  acid  ] 
(66  -f  2)  =  132,  1  equivalent  of  potassa 
=  48,  and  1  of  soda  =  32.  Its  crystals, 
which  are  large  and  well-defined  prisms, 
often  presenting  eight,  ten,  or  twelve 
sides,  include  8  equivalents  (9X8)  =  72 
of  water. 

It  is  formed  by  dissolving  20  ounces  of 
carbonate  of  so'da  in  10  wine  pints  of 
water,  and  adding,  gradually,  20  ounces 
of  cream  of  tartar,  filtering  the  solution, 
evaporatinsr  it  to  a  skin,  and  crystallizing. 

ROCK  SALT.  Common  salt  found  in 
masses  or  beds  in  the  new  red  sandstone, 
as  in  Cheshire  and  elsewhere. 

ROCKET.     (See  Pyrotechny). 

ROD,  in  brick- work,  is  a  superficies  of 
272  square  feet,  li  brick  thick,  and  con- 
taining about  4500  bricks,  and  from  90  to 
100  bushels  of  mortar.  The  cubic  rod 
is  272  X  1-125  or  306  feet.  It  is  4  or  5 
days'  work  for  the  man  and  laborer. 

ROLLING,  in  mechanics,  is  when  all 
the  parts  of  the  surface  of  one  body  come 
into  successive  contact  with  those  of  ano- 
ther, and  under  such  conditions  as  that, 
at  every  instant,  the  portion  of  the  two 
surfaces  which  have  been  in  contact  are 
exactly  equal.  When  this  condition  is 
not  fulfilled,  the  one  surface  is  said  to 
slide  upon  the  other.  The  friction  of  bo- 
dies in  rolling  is  much  less  than  in  that 
of  sliding;  and  hence  the  advantage  of 
wheels  to  all  kinds  of  carriages.)  (See 
Friction.) 

Rolling.  In  Naval  language,  the  la- 
teral oscillation  of  a  vessel.  This  mo- 
tion, which  is  often  very  great  when  the 
vessel  is  running  before  the  sea,  endan- 
gers the  masts,  strains  the  sides,  and 
loosens  the  decks  at  the  waterways ;  it  is 
also  liable  to  cause  the  guns  to  break 
adrift.  When  the  centre  of  gravity  is 
too  low,  the  oscillations  begin  and  end 
violently.  The  changes  in  the  stowage 
necessary  to  modify  the  nature  or  extent 
of  the  roll  are  made  by  seamen  from  ex- 
perimental knowledge. 

ROLLING  PENDULUM.  A  cylinder 
caused  to  oscillate  in  small  spaces  on  a 
horizontal  plane.  Its  mathematical  ex- 
pressions are  interesting,  but  it  has  been 
applied  to  no  imoortant  practical  purpose. 


ROLLING  TACKLE.  A  tackle  or 
pul  ey  hooked  to  the  weather  quarter  of  a 
yard,  and  to  a  lashing  or  strap  round  the 
mast  near  the  slings  or  parral  of  the  yard ; 
the  object  of  it  is  to  keep  the  yard  con- 
stantly over  to  leeward,  therebydepriving 
it  of  play  and  friction  when  the  ship  rolls 
to  windward. 

ROMAN  ALUM.  An  alum  extracted 
from  the  volcanic  rock  of  the  Solfaterra 
near  Naples  :  it  crystallizes  in  opaque 
cubes,  and  appears  to  contain  more  alu- 
mina than  the  common  octohedral  alum. 

ROOF.  In  architecture,  the  upper- 
most part  of  a  building,  containing  the 
timber  work,  with  its  covering  of  slate, 
lead,  tile,  or  other  material.  Carpenters, 
however,  restrict  their  use  of  the  word  to 
the  timber  framing  alone. 

The  inclination  of  the  sides  of  a  roof 
will,  considering  the  species  of  covering 
to  be  the  same  in  all,  depend  very  much 
on  the  temperature  of  the  country  to 
which  it  is  to  be  adapted.  In  the  south- 
ern and  warm  countries  roofs  do  not  re- 
quire much  elevation,  while  as  we  pro- 
ceed northward  they  require  a  far  greater 
pitch.  In  the  warm,  or,  rather,  hot  cli- 
mates, buildings  require  nothing  more 
than  a  terrace  for  their  covering  ;  but  in 
the  temperate  climates,  wherein  the  lati- 
tude exceeds  42°,  experience  shows  that 
the  flat  covering  of  a  building  cannot  be 
practised  with  any  expectation  of  dura- 
bility. The  rains  of  hot  climates  are  vio- 
lent,' while  those  of  temperate  climates  are 
searching.  In  the  more  northern  lati- 
tudes, the  moisture,  the  driving  nature 
of  the  rain,  and,  in  addition,  the  duration 
of  the  snow  on  the  roofs,  require,  it  is 
obvious,  a  more  considerable  inclination. 
Such  materials  as  lead,  copper,  zinc,  and 
the  like,  which,  supposing  them  one 
piece,  as,  in  fact,  when  used,  they  ought 
to  be,  are  not  fair  examples  from  which 
to  draw  inferences  in  the  theory  whereof 
we  speak ;  for,  if  well  executed,  they 
must  either  of  them  be  considered  ae  one 
homogeneous  piece :  but  in  the  case  of 
tiles,  whether  of  marble,  stone,  or  clay, 
the  case  is  far  differe'nt.  Without  enter- 
ing minutely  into  the  details  of  this  sub- 
ject, we  will  merely  observe  that,  sup- 
posing the  inclination  of  a  roof  to  be  zero 
at  the  equator,  if  we  add  to  it  an  inclina- 
tion of  three  degrees  for  every  climate 
from  the  equator  to  the  polar  circle,  each 
climate  being  taken  at  2b  42'  30",  we  ob- 
tain results  which  show  that  the  roofs  and 
pediments  of  temples  of  antiquity  must 
have  been  well  studied  in  that  useful 
point  of  view  which  regarded  their  dura- 


540 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[roc 


bility  and  impenetrability  by  rain.  The 
theory  would  give  au  inclination  to  roofs 
at  Athens  of  I630,  and  they  are  very 
nearly  so  inclined  ;  the  temple  of  Miner- 
va being  16°,  and  that  of  the  temple  of 
Eretheus  151°.  In  Rome,  according  to 
this  theory,  the  inclination  of  a  roof,  and, 
consequently,  pediment,  should  be  22°  ; 
and  experience  finds  it  varying  from  23° 
to  24i°.  The  advocates  for  the  propriety 
of  strictly  copying  Greek  forms  and  de- 
tails under  the  latitude  of  London  will, 
if  they  have  studied  the  asthetics  of  the 
art,  find  no  little  difficulty  in  establishing 
their  doctrines  after  weighing  this  mat- 
ter impartially.  But  our  limits  prevent 
farther  observation  :  we  will  merely  sub- 
join a  table  conformable  to  the  theory  : 


V.  «c«     , 

Latitude  to 

Length   of 

l'laoe. 

nenrsest 

longest  Dny. 

Minute. 

HP 

Carthagena 

370  36' 

14h.  42m. 

190  12' 

Palermo   . 

38      7 

14    48 

19    48 

(Latitude    of 

) 

Athens  is  38° 

r  • 

(see  above.) 

5')  .    .    . 

Lisbon  .    . 

38    42 

14    50 

20      0 

Madrid   .    . 

40    25 

15      0 

21      0 

Naples 

40    50 

15      2 

21     12 

Rome     .    . 

41     54 

15     10 

22      0 

Paris    .    . 

48    50 

16      6 

27    36 

London  .    . 

51    31 

16    34 

30    24 

Amsterdam 

52    22 

16    44 

31    24 

Edinburgh . 

55    57 

17    32 

36    12 

Petersburgh 

59    56 

18    44 

43    24 

A  roof  as  respects  its  construction,  in- 
volves some  knowledge  of  mathematics. 
Of  the  general  principles   on  which  its 

E roper  construction  depends,  we  shall 
ere  subjoin  some  account.  The  obvious 
mode  of  covering  a  building,  where  a 
greater  or  lesser  inclination  of  the  sides 
of  the  roof  is  required  by  the  climate,  is 
to  place  two  sloping  rafters  upon  the 
walls.  If  the  walls  be  not  of  sufficient 
weight,  the  thrust  that  will  be  thus  ex- 
erted on  them  by  -the  tendency  of  the 
rafters  to  spread  at  their  feet  will  throw 
the  walls  out  of  an  upright,  and  the  whole 
assemblage  will  be  destroyed.  By  the 
laws  of  mechanics  it  is  known  that  the 
horizontal  thrust  thus  acting  on  the  walls 
is  proportional  to  the  length  of  a  line 
drawn  at  right  angles  to  the  rafter,  inter- 
secting a  vertical  line  drawn  from  the 
apex,  which  it  is  manifest  must  increase 
as  the  roof  becomes  flatter.  To  counter- 
act the  thrust  above  mentioned,  nothing 
more  is  necessary  than  to  tie  together  the 


feet  of  the  rafters  by  a  tie  beam.  If  the 
extent  be  not  very  great,  the  rafters  may 
be  kept  from  spreading  by  a  minor  tie, 
called  a  collar.  Beyond  certain  lengths 
or  spans,  however,  it  will  occur  to  the 
reader  that  a  tie-beam  will  itself  have  a 
tendency  to  bend,  or  sag,  as  the  workmen 
call  it,  in  the  middle  ;  and  from  this  cir- 
cumstance a  fresh  contrivance  becomes 
necessary,  this  is  called  a  king-post,  or, 
more  properly,  king  piece,  inasmuch  as  it 
does  not  perform  the  office  of  a  post,  but 
rather  of  a  tie,  for  it  ties  up  the  beam  to 

{>revent  its  bending.  If  the  rafters  be  so 
ong  as  to  be  liable  to  bend,  two  pieces 
called  struts,  are  introduced  ;  which,  hav- 
ing their  footing  against  the  sides  of  the 
king  post,  act  as  posts  to  support  or  strut 
up  the  rafters  at  their  weakest  point. 
The  piece  of  framing  thus  eontrived  is 
altogether  called  a  truss.  It  is  obvious 
that  by  means  of  the  upper  joints  of  the 
struts  we  obtain  more  points  of  support, 
or  rather  suspension  ;  and  that  but  for 
the  compressibility  of  the  timber,  there 
would  be  no  limit  to  the  space  which  a 
roof  might  be  made  to  cover.  This  com- 
pressibility takes  place  at  those  points 
where  the  fibres  of  the  wood  are  pressed 
at  right  angles,  or  nearly  so,  with  their  di- 
rection, and  many  ways  are  adopted  for 
avoiding  this  inconvenience.  The  curb 
or  mansard  roof  is  one  in  which  a  story 
is  obtained.  Its  principles  are  the  same 
as  those  already  mentioned,  and  do  not 
here  require  farther  notice.  In  the  exe- 
cution of  roofs  the  expense  of  trussing 
every  pair  of  rafters  would  be  unnecessa- 
ry, and  the  practice  would  also  load  the 
walls  with  a  far  greater  weight  than 
would  be  expedient :  it  is  therefore  the 
custom  to  place  these  principal  parts  of  a 
roof  at  certain  intervals,  which,  however, 
should  never  exceed  ten  feet.  The  raf- 
ters which  are  actually  trussed  are  called 
principal  rafters  ;  and  by  the  intervention 
of  the  purline  are  made  to  bear  the  small- 
er or  common  rafters,  which  are  notched 
down  on  it.  These  common  rafters  are 
received  by  or  pitch  upon  a  plate  called 
a  pole-plate  ;  and  the  principal  rafters, 
which  fall  on  the  tie-beam,  are  ultimately 
borne  by  the  wall-plate. 

"When  beams,  in  either  roofs  or  floors, 
are  so  long  that  they  cannot  be  procured 
in  one  piece,  two  pieces  to  form  the  re- 
quired length  are  scarfed  together,  by 
indenting  them  at  their  joints  and  bolt- 
ing them  together,  of  which  practice  twe 
modes  are  here  subjoined. 

ROPE-MAKING.  The  fibres  of  hemp 
which  compose  a  rope,  seldom  exceed  in 


ROP] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


541 


length  three  feet  and  a  half,  at  an  average. 
They  must,  therefore,  he  twined  together 
so  as  to  unite  them  into  one;  and  this 
union  is  effected  by  the  mutual  eircum- 
torsion  of  the  two  fibres.  If  the  com- 
pression thereby  produced  be  too  great, 
the  strength  of  the  fibres  at  the  points 
where  they  join  will  be  diminished ;  so 
that  it  becomes  a  matter  of  great  conse- 
quence to  give  thetn  only  such  a  degree 
of  twist  as  is  essential  to  their  union. 

The  first  part  of  the  process  of  rope- 
making  by  hand,  is  that  of  spinning  the 
yarns  or  threads,  which  is  done  in  a  man- 
ner analogous  to  that  of  ordinary  spin- 
ning. The  spinner  carries  a  bundle  of 
dressed  hemp  round  his  waist ;  the  two 
ends  of  the  bundle  being  assembled  in 
front.  Having  drawn  out  a  proper  num- 
ber of  fibres  with  his  hand,  he  twists  them 
witii  iiis  fingers,  and  fixing  this  twisted 
part  to  the  hook  of  a  whirl,  which  is  dri- 
ven by  a  wheel  put  in  motion  by  an  as- 
sistant, he  walks  backwards  down  the 
rope-walk,  the  twisted  part  always  serv- 
ing to  draw  out  more  fibres  from  the  bun- 
dle round  his  waist,  as  in  the  flax-spin- 
ning wheel.  The  spinner  takes  care  that 
these  fibres  are  equably  supplied,  and 
that  they  always  enter  the  twisted  parts 
by  their  ends,  and  never  by  their  middle. 
As  soon  as  he  has  reached  the  termina- 
tion of  the  walk,  a  second  spinner  takes 
the  yarn  off  the  whirl  and  gives  it  to 
another  person  to  put  upon  a  reel,  while 
he  himself  attaches  his  own  hemp  to  the 
whirl  hook,  and  proceeds  down  the  walk. 
When  the  person  at  the  reel  begins  to 
turn,  the  first  spinner,  who  has  complet- 
ed his  yarn,  holds  it  firmly  at  the  end, 
and  advances  slowly  up  the  walk,  while  . 
the  reel  is  turning,  keeping  it  equally 
tight  all  the  way,  till  he  reaches  the  reel, 
where  he  waits  till  the  second  spinner 
takes  his  yarn  off  the  whirl  hook,  and 
joins  it  to  the  end  of  that  of  the  first 
spinner,  in  order  that  it  may  follow  it  on 
the  reel. 

The  next  part  of  the  process  previous 
to  tarring,  is  that  of  warping  the  yarns, 
or  stretching  them  all  to  one  length, 
which  is  about  200  fathoms  in  full-length 
rope-grounds,  and  also  in  putting  a  slight 
turn  or  twist  into  them. 

The  third  process  in  rope-making,  is 
the  tarring  of  the  yarn.  Sometimes  the 
yarns  are  made  to  wind  off  one  reel,  and, 
naving  passed  through  a  vessel  of  hot 
tar,  are  wound  upon  another,  the  super- 
fluous tar  being  removed  by  causing  the 
yarn  to  pass  through  a  hole  surrounded 
with  spongy  oakum  ;  but  the  ordinary 


method  is  to  tar  it  in  skeins  or  hanks, 
which  are  drawn  by  a  capstan  with  a  uni- 
form motion  through  the  tar-kettle.  In 
this  process,  great  care  must  be  taken 
that  the  tar  is  boiling  neither  too  fast  nor 
too  slow.  Yarn  for  cables  requires  more 
tar  than  for  hawser-laid  ropes ;  and  for 
standing  and  running  rigging,  it  requires 
to  be  merely  well  covered.  Tarred  cor- 
dage has  been  found  to  be  weaker  than 
what  is  untarred,  when  it  is  new;  but 
the  tarred  rope  is  not  so  easily  injured  by 
immersion  in  water. 

The  last  part  of  the  process  of  rope- 
making,  is  to  lay  the  cordage.    For  this 
purpose  two  or  more  yarns  are  attached 
at  one  end  to  a  hook.    The  hook  is  then 
turned  the  contrary  way  from  the  twist 
of  the  individual  yarn,  and  thus  forms 
what  is  called  a  strand.     Three  strands, 
sometimes  four,  besides  a  central  one,  are 
then  stretched  at  length,  and  attached  at 
one  end  to  three  contiguous  but  separate 
hooks,  but  at  the  other  end  to  a  single 
hook  ;  and  the  process  of  combining  them 
together,  which  is  effected  by  turning  the 
single  hook  in  a  direction  contrary  to  that 
of  the  other  three,  consists  in  so  regulate 
ing  the  progress  of  the  twists  of  the 
strands  round  their  common  axis,  that  the 
three  strands  receive  separately  at  their 
opposite  ends  just  as  much  twist  as  is  tak- 
en out  of  thern  by  their  twisting  the  con- 
trary way,  in  the  process  of  combination. 
Large  ropes  are  distinguished  into  two 
main  classes,  the  cable-laid  and  hawser- 
laid.     The  former  are  composed  of  nine 
strands,  namely,  three  great  strands,  each 
of  these  consisting  of  three  smaller  se- 
condary strands,  which  are  individually 
formed  with  an  equal  number  of  primi- 
tive yarns.    A  cable-laid  rope  eignt  in- 
ches in  circumference,  is  made  up  of  333 
yarns  or  threads,  equally  divided  among 
the  nine  secondary  strands.    A  hawser- 
laid  rope  consists  of  only  three  stands, 
each  composed  of  a  number  of  primitive 
yarns,   proportioned  to  the  size  of  the 
rope ;  for  example,  if  it  be  eight  inches 
in  circumference,  it  may  have  414  yarns, 
equally  divided    among  three    strands. 
Thirty   fathoms   of  yarn  are  reckoned 
equivalent  in  length  to  eighteen  fathoms 
of  rope  cable-laid,  and  to  twenty  fathoms 
hawser-laid.     Ropes  of  from  one  inch  to 
two  inches  and  a  half  in  circumference 
are  usually  hawser-laid  ;  of  from  three  to 
ten  inches,  are  either  hawser  or  cable- 
laid  ;  but  when  more  than  ten  inches, 
they  are  always  cable-laid. 

Dr.  Ure  gives   the  following  relative 
strength  of  cordage,  shroud-laid  : — 


542 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[ros 


Size. 

Warm  Register. 

Cold  Register. 

Common  Stapl 

B. 

Tons. 

Cwts 

Qrs. 

Lbs. 

Tons. 

Cwts.    Qrs. 

Lbs. 

Tow.  Owts. 

Qrs. 

Lbs. 

3  inches  bore 

3 

17 

— 

16 

3 

5 

3 

16 

2 

9 

1 

24 

3*       « 

5 

5 

— 

— 

4 

9 

2 

21 

3 

6 

1 

27 

4         " 

6 

17 

— 

16 

5 

17 



4 

4 

5 

3 

7 

4§        " 

8 

13 

2 

8 

7 

5 

3 

1 

5 

1 

2 

6 

5          « 

10 

14 

I 

4 

9 

3 



4 

6 

9 

2 

8 

5*        » 

12 

19 

2 

4 

11 

1 

1 

25 

7 

12 

22 

6         « 

14 

15 

2 

24 

13 

3 

2 

8 

8 

17 

1 

20 

6J        « 

18 

2 

■  — 

10 

15 

9 

I 

9 

9 

16 

3 

14 

7         " 

21 

— 

— 

— 

17 

18 

3 

8 

11 

4 

1 

21 

»        « 

24 

2 

— 

16 

20 

11 

3    1 

9 

12 

8 

3 

6 

6 

27 

8 

1 

26 

23 

8 

2 

8 

13          2 

3 

12 

A  test  trial,  of  Manilla  and  Kyanized 
American  rope,  was  had  at  Griffey's 
Foundry,  Cincinnati,  which  resulted  most 
favorably  to  the  American  manufacture. 
A  small  Manilla  rope,  of  the  best  quality 
of  Boston  make,  was  first  tried,  and  was 
broken,  after  sustaining  a  weight  of  1520 
pounds.  The  Kyanized  rope,  invented 
and  manufactured  by  J.  T.  Crook  &  Co., 
of  Maysville,  was  then  put  to  the  same 
test,  and  sustained  a  weight  of  2,320 
pounds  before  parting.  A  second  trial 
was  then  had  of  the  same  size  of  Manilla 
rope,  which  sustained  a  weight  of  2,200 

Iiounds.  A  second  trial  was  then  also 
lad  of  the  Kyanized  rope,  and  sustained 
a  pressure  of  2,410  pounds.  Two  trials 
were  then  had  with  a  larger  size  of  the 
Manilla  rope,  manufactured  by  Bonte, 
which  parted  first  at  2,840  pounds,  and 
on  the  second  trial  at  2,796  pounds.  One 
trial  was  then  made  with  the  Kyanized 
rope,  which  sustained  the  weight  of  3,220 
pounds  before  parting.  The  average  dif- 
ference in  favor  of  the  Kyanized  unrotted 
hemp  rope  being  in  the  first  trials  500 
pounds,  and  in  the  last  trial  400  pounds. 
This  shows  that  the  Manilla  rope,  which 
lias  always  been  considered  the  best  that 
was  ever  used,  is  far  inferior  to  the  Ame- 
rican unrotted  hemp  rope.  The  Kyaniz- 
ed rope  is  manufactured  from  the  unrot- 
ted hemp,  and  is  not  only  the  strongest 
rope  made,  but  by  the  chemical  process 
of  Kyanizing,  is  by  far  the  most  durable. 
(See  Hemp.) 

KOSE  ENGINE.  Tn  mechanics,  an 
appendage  to  the  turning  lathe,  by  which 
a  surface  of  wood  or  metal,  as  a  watch- 
case,  is  engraved  with  a  variety  of  curved 
lines.  The  assemblage  of  these  lines  pre- 
senting some  resemblance  to  a  full-blown 
rose,  is  called  by  the  French  rosette  ;  and 
hence  the  engine  by  which  the  ornament 
is  produced  is  called  a  rose-engine.  The 
mechanism  by  which  the  figures  are  pro- 


duced is  sometimes  called  a  camb,  and 
may  be  described  as  follows  :  '  A  wheel 
upon  the  axle  turns  uniformly  in  one  di- 
rection. A  rod  moves  in  guides,  which 
only  permit  it  to  ascend  and  descend  per- 
pendicularly. Its  extremity  rests  upon  a 
path  or  groove  raised  from  the  face  of  the 
wheel,  and  shaped  into  such  a  curve  that 
as  the  wheel  revolves  the  rod  shall  be 
moved  alternately  in  opposite  directions, 
through  the  guides,  with  the  required 
velocity.  The  manner  in  which  the  ve- 
locity varies,  will  depend  on  the  form 
given  to  the  groove  or  channel  raised 
upon  the  face  of  the  wheel ;  and  this  may 
be  shaped  so  as  to  give  any  variation  to 
the  motion  of  the  rod  which  may  be  re- 
quired for  the  purpose  to  which  it  is  to 
be  applied. 

The  purpose  of  the  machine  is  therefore 
to  convert  a  uniform  rotatory  movement 
into  a  varied  rectilinear  and  alternating 
movement.  It  is  also  used  in  machinery 
for  spinning,  and  for  lace- making. 

KOSIN,  or  COLOPHONY  is  the  mass 
left  alter  distilling  off  the  volatile  oil  from 
the  different  species  of  turpentine.  Yel- 
low rosin  contains  some  water,  which 
black  rosin  does  not.  (See  Turpentine.) 
KOSIN  GAS.  Illuminating  gas  made 
from  rosin  was,  until  lately,  manufactur- 
ed largely  in  New-York  and  other  cities. 
It  furnishes  a  very  pure  gas,  but  cannot 
be  made  as  cheaply  as  tfiat  from  coal. 
The  apparatus  used  in  the  manufacture 
of  oil  gas  is  adapted  for  that  of  rosin  gas. 
(See  Oil  Gas.)  Mr.  Daniel,  of  London, 
prepared  an  apparatus  for  this  end  which 
is  as  follows  : 

The  melted  rosin  having  passed  by  the 
stopcock,  funnel,  and  syphon,  into  the 
retort,  falls  on  the  coke,  'and  in  its  pas- 
sage through  the  ignited  mass,  becomes 
decomposed.  On  arriving  at  the  other 
end  of  the  retort,  a  large  portion  of  the 
oil  of  turpentine,  in  the  form  of  conden- 


rul] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


543 


Bablc  vapor,  is  separated  by  the  refrigera- 
tor ;  this  is  supplied  with  water  from  a 
cistern  above,  and  the  non-condensable 
vapor  or  gas  passes  up  the  tube  and  dips 
beneath  the  surface  of  the  fluid  in  the 
main.  This  completes  the  condensation ; 
and  the  gas  proceeds  in  a  perfectly  pure 
state,  by  a  pipe,  to  the  gasometer,  or  ra- 
ther to  the  floating  reservoir,  for  use. 

The  essential  oil,  when  it  leaves  the  re- 
frigerator, is  conveyed,  by  the  syphon,  to 
a  cistern  beneath.  The  necessity  for  em- 
ploying a  syphon  will  be  apparent,  when 
it  is  borne  in  mind  that  the  tube  prevents 
the  escape  of  the  gas,  which  would  other- 
wise pass  away  from  the  box  with  the  es- 
sential oil.  Another  pipe  and  syphon 
serve  to  convey  the  condensed  essential 
oil  from  the  top  cistern. 

ROTARY  ENGINE.  An  apparatus  of 
this  kind  has  been  invented  by  Capt. 
Hon.  W.  E.  Fitzmaurice,  and  a  Mr.  Hart- 
ford. It  is  described  as  "  very  simple, 
merely  consisting  of  two  pieces  so 
mathematically  arranged  that  the  interior 
part  works  in  the  outer  with  the  greatest 
case,  being  free  from  dead  points  and 
without  the  slightest  vibration,  however 
great  the  velocity.     It  has  no  springs  or 

Eacking,  and  the  parts  meet  each  other  so 
armoniously  as  only  to  give  a  humming 
noise  like  a  spinning  top,  and  it  is  not  in 
the  least  liable  to  get  out  of  order,  the 
wear  being  perfectly  uniform  throughout. 
The  entire  motion  being  a  rolling  instead 
of  a  cutting  one,  the  engine  will  last  long 
without  repair,  as  the  surfaces  become 
case-hardened  in  a  very  short  space  of 
time.  The  trials  took  place  in  the  pre- 
sence of  several  scientific  gentlemen  and 
engineers  of  eminence  in  their  profes- 
sion, in  a  frigate's  pinnace,  the  engine 
being  constructed  for  the  Govern- 
ment." 

It  also  states  that  it  propelled  a  boat  of 
80  tons  burden  at  the  rate  of  8  miles  per 
hour,  with  a  screw,  and  that  an  engine  of 
100  horse  power,  would  only  take  up  a 
space  of  4  by  2  feet.  We  venture  to  say 
that  the  Hon.  Fitzmaurice's  rotary  en- 
gine will  soon  be  numbered  with  the 
things  that  were. 

ROTTEN  STONE.  (See  Tripoli.) 
ROUGE.  The  only  cosmetic  which 
can  be  applied  without  injury  to  brighten 
a  lady's  complexion,  is  that  prepared  from 
safflower  (Uarthamus  tlnctorius).  The 
flowers,  after  being  washed  with  pure 
water  till  it  comes  off  colorless,  are  dried, 
pulverized,  and  digested  with  a  weak  so- 
lution of  crystals  of  soda,  which  assume 
thereby  a  yellow  color.    Into  this  liquor 


a  quantity  of  finely  carded  white  cotton 
wool  is  plunged,  and  then  so  much  lemon 
juice  or  pure  vinegar  is  added  as  to  su- 
persaturate the  soda.  The  coloring  mat- 
ter is  disengaged,  and  falls  down  in  an 
impalpable  powder  upon  the  cotton  fila- 
ments. The  cotton,  after  being  washed 
in  cold  water,  to  remove  some  yellow  co- 
loring particles,  is  to  be  treated  with  a 
fresh  solution  of  carbonate  of  soda,  which 
takes  up  the  red  coloring  matter  in  a 
state  of  purity.  Before  precipitating  this 
pigment  a  second  time  by  the  acid  of  le- 
mons, some  soft  powdered  talc  should  be 
laid  in  the  bottom  of  the  vessel,  for  the 
purpose  of  absorbing  the  fine  rouge,  in 
proportion  as  it  is  separated  from  the 
carbonate  of  soda,  which  now  holds  it 
dissolved.  The  colored  mixture  must  be 
finally  triturated  with  a  tew  drops  of 
olive  oil,  in  order  to  make  it  smooth  and 
marrowy.  Upon  the  fineness  of  the  talc, 
and  the  proportion  of  the  safflower  pre- 
cipitate which  it  contains,  depend  the 
beauty  and  value  of  the  cosmetic.  The 
rouge  of  the  above  second  precipitation 
is  received  sometimes  upon  bits  of  fine- 
twisted  woollen  stuff,  called  crepons, 
which  ladies  rub  upon  their  cheeks. 

RUBY.     (^Lapidary.) 

ROUGH-CAST.  In  architecture,  the 
plastering  of  walls  with  mortar  and  fine 
gravel,  left  rough  without  any  smoothing. 

ROUGH  STUCCO.  In  architecture, 
stucco  floated  and  brushed  in  a  small  de- 
gree with  water. 

RULES,  BRASS.  Pieces  of  brass  of 
different  thicknesses  made  letter  high,  to 
print  with.  They  are  made  in  lengths  of 
fourteen  inches,  out  of  late  years  lengths 
half  as  long  again  have  been  made.  One 
of  the  edges  is  bevelled  so  as  to  print  a 
fine  line,  and  when  a  thicker  line  is  re- 
quired the  bottom  edge  is  placed  upper- 
most, which  is  the  full  thickness  of  the 
brass  ;  by  this  means  lines  of  different 
thicknesses  are  obtained,  and  also  double 
lines,  a  thick  one  and  a  fine  one,  when 
required.  They  are  used  for  column 
lines  in  table  work  ;  to  separate  matter 
that  requires  to  be  distinct;  and  to  be 
placed  round  pages. 

In  cases  where  diagrams  are  required, 
and  there  is  no  engraver  within  reach, 
they  may  be  formed  by  a  clever  workman 
with  brass  rule.  Of  late  years  many  in- 
genious and  elaborate  imitations  of  archi- 
tectural drawings  of  buildings,  with  pil- 
lars, &c.  have  been  made  with  brass 
rule. 

RULE,  CARPENTER'S.  A  folding 
ruler,  generally  used  by  carpenters  ana 


544 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SAF 


other  artificers,  having  a  variety  of  scales 
adapted  to  facilitate  the  calculations  of 
most  frequent  occurrence  by  inspection. 
Sometimes  it  has  a  sliding  piece  in  one  of 
its  legs,  by  which  its  use  is  greatly  ex- 
tended. • 

RULE,  GAUGING,  is  a  rule  adapted 
in  the  same  manner  to  discover  the  con- 
tents of  casks  and  other  vessels.  It  is 
used  by  the  officers  of  excise  in  surveying 
the  articles  in  the  process  of  manufacture 
that  are  liable  to  duties. 

KUT1LITE.     Native  oxide  of  titanium. 

BY  ACOL1TE.  A  name  given  to  glassy 
feldspar. 

EYE,  according  to  some,  is  a  native  of 
Crete;  butit  is  very  doubtful  if  it  be  found 
wild  in  any  country.  It  has  been  culti- 
vated from  time  immemorial,  and  is  con- 
sidered as  coming  nearer  in  its  proper- 
ties to  wheat  than  any  other  grain.  It  is 
more  common  than  wheat  in  many  parts 
of  middle  Europe ;  being  a  more  certain 
crop,  and  requiring  less  culture  and  ma- 
nure. It  is  the  bread  corn  of  Germany 
and  Eussia.  In  Britain  it  is  now  very 
little  grown,  being  no  longer  a  bread  corn  ; 
and  therefore  of  less  value  to  the  farmer 
than  barlev,  oats,  or  peas. 

SACCHAEOMETEE  is  the  name  of  a 
hydrometer,  adapted  by  its  scale  to  point 
out  the  proportion  of  sugar,  or  the  sac- 
charine matter  of  malt,  contained  in  a 
solution  of  any  specific  gravity.  Brew- 
ers and  distillers  sometimes  denote 
by  the  term  gravity,  the  excess  of 
weight  or  1,000  parts  of  a  liquid  by  vol- 
ume above  the  weight  of  a  like  volume 
of  distilled  water  ;  so  that  if  the  specific 
gravity  be  1,045,  1,070  1,090,  &c,  the 
gravity  is  said  to  be  45,  70,  or  90 ;  at  oth- 
ers, they  denote  the  weight  of  saccharine 
matter  in  a  barrel  (36  gallons)  of  worts ; 
and  again,  they  denote  the  excess  in 
weight  of  a  barrel  of  worts  over  a  bar- 
rel of  water,  equal  to  36  gallons,  or  360 
pounds.  This  and  the  first  statement 
are  identical,  only  1,000  is  the  standard 
in  the  first  case,  and  360  in  the  second. 

The  saccharometer  now  used  in  Eng- 
land by  the  trade,  is  that  constructed  by 
Mr.  E.  B.  Bate,  well  known  for  the  accu- 
racy of  his  philosophical  and  mathemati- 
cal instruments.  The  tables  published 
by  him  for  ascertaining  the  values  of 
wort  or  wash,  and  low  wines,  are  prece- 
ded by  explicit  directions  for  their  use. 
"  The  instrument  is  composed  of  brass  ; 
the  ball  or  float  being  a  circular  spindle, 
in  the  opposite  ends  of  which  are  fixed  a 
stem  and  a  loop.  The  stem  bears  a  scale 
cf  divisions  numbered  downward  from 


the  first  to  30  ;  these  divisions,  which 
arc  laid  down  in  an  original  manner,  ob- 
serve a  diminishing  progression  accord- 
ing to  true  principles  ;  therefore  each  di- 
vision correctly  indicates  the  one  thou- 
sandth part  of  the  specific  gravity  of 
water  ;  and,  further,  by  the  alteration 
made  in  the  bulk  of  the  sacchrometer  at 
every  change  of  poise,  each  of  the  same 
divisions  continues  to  indicate  correctly 
the  said  one  thousandth  part  through*- 
out." 

Dr.  Ure  prefers  to  take  specific  gravi- 
ties of  all  liquids  whatever  with  a  ghiss 
globe  containing  500  or  1,00  grains  of  dis- 
tilled water  at  60°  Fahr.,  when  it  is 
closed  with  a  capillary-bored  glass  stop- 
per ;  and  with  the  gravity  so  taken,  to 
look  into  a  table  constructed  to  show  the 
quantity  per  cent,  of  sugar,  malt,  extract, 
or  of  any  other  solid,  proportional  to  the 
density  of  the  solution.  By  bringing  the 
liquid  in  the  gravity-bottle  to  the  stand- 
ard temperature,  no  correction  on  this 
account  is  needed. 

SACCHAEIC  ACID.  An  uncrystalli- 
zable  acid  product,  formed  along  with 
oxalic  acid  during  the  action  of  nitric  acid 
on  sugar. 

SA'CCHAEOID.  A  texture  resembling 
that  of  loaf  sugar  ;  as  saccharoid  carbon- 
ate of  lime.  &c. 

SACCHOLACTIC  ACID.  An  acid 
obtained  by  digesting  sugar  of  milk  in 
nitric  acid.  It  is  identical  with  that  ob- 
tained from  gum,  and  termed  mucous  acid. 

SAFETY  LAMP.  A  lamp  invented 
by  Sir  H.  Davy,  which  is  so  constructed 
as  to  burn  without  any  danger  in  an  ex- 
plosive atmosphere.  Flame  may  be  con- 
sidered as  vapor  or  aeriform  matter  in  a 
state  of  intense  ignition  ;  the  tempera- 
ture, therefore,  of  flame  is  always  very 
high.  It  is,  however,  independent  of  its 
luminosity  ;  for  some  of  the  dimmest 
flames,  those  of  pure  hydrogen  gas,  and 
of  alcohol,  for  instance,  are  those  which 
are  hottest ;  and  that  this  is  so  may  be 
shown  by  projecting  into  them  finely- 
powdered  substances,  such  as  magnesia 
or  lamp-black,  or  by  holding  in  them 
fine  platinum  wire,  when  the  intensity  of 
their  temperature  is  rendered  evident  by 
those  substances  becoming  white  hot. 
And  whenever  flames  emit  much  light 
they  derive  that  property  from  the  pres- 
ence of  finely  divided  matter  diffused 
through  them  :  thus,  the  intense  bril- 
;  liancy  of  the  flame  of  phosphorus'  ap- 
'<  pears  to  depend  upon  the  particles  of  in- 
combustible phosphoric  acid  diffused 
i  through  it ;  and  the  bright  light  emitted 


8AF] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


545 


by  a  gas  flame  depends  upon  finely- divi- 
ded charcoal,  which  is  ignited  by  the  gas 
and  at  the  same  time  burned.  The  cor- 
rectness of  this  ifbeory  of  flame  is  shown 
by  the  circumstance  of  its  being  extin- 
guished by  cooling  ;  and  this  is  best  ef- 
fected by  causing  it  to  pass  through  a  piece 
of  tine  wire  gauze,  which,  when  held  hori- 
zontally in  the  midst  of  the  flame,  extin- 
guishes its  upper  part :  the  inflammable 
vapor  or  gas,  and  the  soot  or  carbon,  pass 
through,  but  in  passing  are  so  far  cooled 
as  to  be  extinguished  ;  they  may,  how* 
ever,  be  rekindled  by  applying  a  flame 
above  the  wire  gauze.  That  the  wire 
gauze  merely  acts  by  its  cooling  power, 
is  shown  by  the  flame  passing  through  it 
when  it  acquires  a  white  heat,  or  when  its 
meshes  are  not  fine  enough  to  exert  a  due 
cooling  power ;  it  is  also  found  that  very 
hot  flames,  such  as  that  of  hydrogen,  will 
pass  through  tissues  which  are  imper- 
vious to  flames  of  a  lower  temperature, 
such  as  that  of  a  common  candle  or  a  gas 
flame.  The  application  of  these  princi- 
ples to  the  construction  of  the  safety 
lamp  is  as  follows  :  The  flame  of  a 
small  oil  lamp  is  surrounded  by  a  cylin- 
der of  wire  gauze,  doubled  where  likely 
to  become  hottest,  and  protected  by  the 
stout  wire  frame,  and  burns  within  it, 
the  air  having  free  ingress  and  egress. 
"When  it  is  immersed  in  an  explosive  at- 
mosphere, such  as  that  of  a  coal  mine  in- 
fested by  fire-damp,  the  inflammable 
fas  enters  without  and  burns  i/n  the  cage  ; 
ut,  in  consequence  of  the  cooling  power 
of  the  wire  gauze,  no  flame  can  pass 
outwards  so  as  to  ignite  the  surround- 
ing atmosphere  :  the  miner,  therefore,  is 
warned  ol  his  danger  by  the  appearance 
of  his  lamp.  As  long  as  the  external  at- 
mosphere is  safe,  the  lamp  burns  as  usu- 
al ;  but  upon  the  approach  of  the  fire- 
damp the  flame  is  more  or  less  enlarged  ; 
and  in  the  most  explosive  condition  of 
the  surrounding  air  the  cylinder  appears 
filled  with  a  blue  lambent  flame,  which 
flickers,  within  it,  the  wick  of  the  lamp 
appearing  for  the  time  extinguished.  It 
is,  however,  rekindled  as  the  air  becomes 
more  pure  ;  or  should  the  fire-damp 
greatly  predominate,  it  may  be  entirely 
extinguished.  Before  this  happens,  how- 
ever, the  miner  is  duly  apprised  of  his 
danger,  and  has  time  to  retreat.  (See 
Lamp  of  Davy.) 

SAFETY  VALVE.  (See  Steam  En- 
gine and  Valve.) 

SAFFLOWER,  or  Carthamus.— Wa- 
tery menstrua  take  up  only  the  yellow, 
and  leave  the  red  color  to  be  afterwards 


be  extracted  by  alcohol,  or  bj  a  weak  so- 
lution of  alkali.  This,  after  the  yellow 
matter  has  been  extracted  by  water, 
gives  a  tincture  to  ley,  from  which,  on 
standing  at  rest  for  some  time,  a  deep 
red  fecula  subsides,  called  cartkamine. 
This  pigment  impregnates  alcohol  with  a 
beautiful  red  tincture,  but  communicates 
no  color  to  water.     (See  Rouge.) 

Carthamus  is  used  for  dyeing  silk  of  a 
poppy,  cherry,  rose,  or  bright  orange- 
red.  After  the  yellow  matter  is  extracted, 
the  cakes  are  put  into  a  deal  trough,  and 
sprinkled  at  different  times  with  soda, 
well  powdered  and  sifted,  in  the  propor- 
tion of  six  pounds  to  a  hundred,  mixing 
the  alkali  with  carbonic  acid.  The  car- 
thamus is  then  put  on  a  cloth,  in  a  trough 
with  a  grated  bottom,  placed  on  a  larger 
trough,  and  cold  water  poured  on.  And 
this  is  repeated,  with  the  addition  of  lit- 
tle more  alkali,  till  the  red  is  exhausted. 
Lemon-iuice  is  then  poured  into  the 
bath,  till  it  is  turned  of  a  fine  cherry  col- 
or, and,  after  it  is  well  stirred,  the  silk  is 
immersed  in  it.  The  silk  is  wrung, 
drained,  and  passed  through  fresh  baths, 
washing  and  drying  after  every  opera- 
tion ;  when  it  is  brightened  in  hot  water 
and  lemon-juice.  For  a  poppy  or  fire 
color,  a  slight  annotto  ground  is  first 
giveu  ;  but  the  silk  should  not  be  al- 
umed.  For  a  pale  carnation,  a  little  soap 
should  be  put  into  the  bath. 

SAFFRON.  The  prepared  stigmata 
of  the  Crocus  sativus.  rlhe  stigmata»of 
this  purple  crocus  are  of  a  deep  orange 
color,  and  when  in  quantity  have  a  pecu- 
liar and  very  characteristic  odor;  they  are 
used  im  medicine,  chiefly  as  a  rich  yellow 
or  orange  coloring  matter.  Saffron  is 
now  chiefly  imported  from  the  south 
of  Europe,  especially  Spain.  Saffron  is 
often  largely  adulterated  with  the  petals 
of  other  plants,  especially  with  those  of 
the  marigold. 

It  contains  a  yellow  matter  called  poly- 
chroite, because  a  small  quantity  of  it  is 
capable  of  coloring  a  great  body  of  water. 
This  is  obtained  by  evaporating  the  wa- 
tery infusion  of  saffron  to  the  consist- 
ence of  an  extract,  digesting  the  extract 
with  alcohol,  and  concentrating  the  alco- 
holic solution.  The  polychroite  remains 
in  the  form  of  a  brilliant  mass,  of  a  red- 
dish-yellow color,  transparent,  and  of  the 
consistence  of  honey.  It  has  the  agreea- 
ble smell,  with  the  bitter  pungent  taste, 
of  saffron.  It  is  very  soluble  in  water  ; 
and  if  it  be  stove-dried,  it  deliquesces 
speedily  in  the  air.  According  to  M. 
llcnry^re,  polychroite  consists  of  eighty 


546 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[SA1 


parts  of  coloring  matter,  combined  with 
20  parts  of  a  volatile  oil,  which  cannot  be 
separated  by  distillation  till  the  coloring 
matter  has  been  combined  with  an  alka- 
li. By  mixing  one  part  of  shred  saffron 
with  eight  parts  of  saturated  brine,  and 
one  halt  of  caustic  ley,  and  distilling  the 
mixture,  the  oil  comes  over  into  the  re- 
ceiver, and  leaves  the  coloring  matter  in 
the  retort,  which  may  be  precipitated 
from  the  alkaline  solution  by  an  acid. 
The  pure  coloring  matter,  when  dried,  is 
of  a  scarlet  hue,  and  then  readily  dis- 
solved in  alcohol,  as  also  in  the  fat  and 
volatile  oils,  but  sparingly  in  water. 
Light  blanches  the  reddish-yellow  of  saf- 
fron, even  when  it  is  contained  in  a  full 
vial  well  corked.  Polychroite,  when 
combined  with  fat  oil,  and  subjected  to 
dry  distillation,  affords  ammonia,  which 
shows  that  azote  is  one  of  its  constitu- 
ents. Sulphuric  acid  colors  the  solution 
of  polychroite  indigo  blue,  with  a  lilach 
cast ;  nitric  acid  turns  it  green  of  vari- 
ous shades,  according  to  the  state  of  di- 
lution. Protochloride  (muriate)  of  tin 
produces  a  reddish  precipitate. 

Saffron  is  employed  as  a  seasoning  in 
French  cookery.  It  is  also  used  to  tinge 
confectionary  articles,  liqueurs,  and  var- 
nishes ;  but  rarely  as  a  pigment. 

SAGO,  is  prepared  from  the  pith  of  the 
Cycas  Circinalis,  and  its  granulated  form 
arises  from  its  being  passed,  while  moist, 
through  a  sieve. 

SAL  AMMONIAC.  Muriate  of  am- 
monia ;  hydrochlorate  of  ammonia.  A 
compound  of  17  of  ammonia  and  37  hy- 
drochloric acid.  Its  name  is  derived 
from  the  Temple  of  Amnion,  in  Egypt, 
where  it  was  originally  made  by  burning 
camels'  dung.     (See  Ammonia.) 

Sal  ammoniac  exists  ready  formed  in 
several  animal  products.  The  dung  and 
urine  of  camels  contain  a  sufficient  quan- 
tity to  have  rendered  its  extraction  from 
them  a  profitable  Egyptian  art  in  former 
times,  in  order  to  supply  Europe  with 
the  article.  In  that  part  of  Africa,  fuel 
being  very  scarce,  recourse  is  had  to  the 
dung  of  these  animals,  which  is  dried 
for  that  purpose,  by  plastering  it  upon 
the  walls.  When  this  is  afterwards 
burned  in  a  peculiar  kind  of  a  furnace,  it 
exhales  a  thick  smoke,  replete  with  sal 
ammoniac  in  vapor  ;  the  soot  of  course 
contains  a  portion  of  that  salt,  condensed 
along  with  other  products  of  combustion. 
In  every  part  of  Egypt,  but  especially  in 
the  Delta,  peasants  are  seen  driving 
asses  loaded  with  bags  of  that  soot,  on 
their  way  to  the  sal  ammoniac  works. 


There  it  is  extracted  in  the  following 
manner.  Glass  globes  coated  with  loam 
are  filled  with  the  soot  pressed  down  by 
wooden  rammers,  a  space  of  only  two  or 
three  inches  being  lett  vacant,  near  their 
months.  These  globes  are  set  in  round 
orifices  formed  in  the  ridge  of  a  long 
vault,  or  large  horizontal  furnace  flue. 
Heat  is  gradually  applied  by  a  fire  of  dry 
camels1  dungr,  and  it  is  eventually  in- 
creased till  the  globes  become  obscurely 
red.  As  the  muriate  of  ammonia  is  vol- 
atile at  a  temperature  much  below  igni- 
tion, it  rises  out  of  the  soot  in  vapor,  and 
gets  condensed  into  a  cake  upon  the  in- 
ner surface  of  the  top  of  the  globe.  A 
considerable  portion,  however,  escapes 
into  the  air  ;  and  another  portion  con- 
cretes in  the  mouth,  which  must  be 
cleared  from  time  to  time  by  an  iron  rod. 
Towards  the  end,  the  obstruction  be- 
comes very  troublesome,  and  must  be 
most  carefully  attended  to  and  obviated, 
otherwise  the  globes  would  explode  by 
the  uucondensed  vapors.  In  all  cases, 
when  the  subliming  process  approaches 
to  a  conclusion,  the  globes  crack  or  split ; 
and  when  they  come  to  be  removed,  after 
the  heat  has  subsided,  they  usually  fall 
to  pieces.  The  upper  portion  of  the 
mass  is  separated  because  to  it  the  white 
salt  adheres  ;  and  on  detaching  the 
pieces  of  glass  with  a  hatchet,  it  is  ready 
for  the  market.  At  the  bottom  of  each 
balloon  a  nucleus  of  salt  remains,  sur- 
rounded with  fixed  pulverulent  matter. 
This  is  reserved,  and  after  being  bruised, 
is  put  in  along  with  the  charge  of  soot 
in  a  fresh  operation. 

The  sal  ammoniac  obtained  by  this 
process  is  dull,  spongy,  and  of  a  grayish 
hue  :  but  nothing  better  was  for  a  long 
period  known  in  commerce.  The  most 
ordinary  process  for  converting  the  am- 
moniacal  liquor  of  the  gas-works  into  sal 
ammoniac,  is  to  saturate  it  with  sulphuric 
acid,  and  to  decompose  the  sulphate, 
thus  formed,  by  the  processes  above  de- 
scribed. But  muriatic  acid  will  be  pre- 
ferred, where  it  is  as  cheap  as  sulphuric 
of  equivalent  saturating  power  ;  because 
a  tolerably  pure  sal  ammoniac  is  thereby 
directly  obtained.  As  the  coal-gas  li- 
quor contains  a  good  deal  of  sulphureted 
hydrogen,  the  saturation  of  it  with  acid 
snould  be  so  conducted  as  to  burn  the 
disengaged  noxious  gases  in  a  chimney. 
Formerly  human  urine  was  very  exten- 
sively employed,  both  in  this  country 
and  in  France,  in  the  manufacture  of  sal 
ammoniac  ;  but  since  the  general  estab- 
lishment of  gas-works,  it  has  been  every 


sal] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


547 


where  abandoned.  The  process  was  ex- 
ceedingly offensive. 

The  best  white  sal  ammoniac  is  in  sphe- 
roidal cakes  of  about  one  foot  diameter, 
three  or  four  inches  thick  in  the  middle, 
somewhat  thinner  at  the  edges,  and  is 
semi-transparent  or  translucent.  Each 
lump  weighs  about  one  quarter  of  a  cwt. 
As  it  is  easily  volatilized  by  heat,  it  may 
be  readily  examined  as  to  its  sophistica- 
tion with  other  salts.  Sal  ammoniac  has 
a  certain  tenacity,  and  is  flexible  under 
the  hammer  or  pestle.  It  is  principally 
used  in  tinning  ot  cast-iron;  wrought- 
iron,  copper,  brass,  and  for  making  the 
various  ammoniacal  preparations  of  phar- 
macy. 

In  a  chemical  factory  near  Glasgow, 
7200  gallons  of  ammoniacal  liquor,  ob- 
tained weekly  from  the  gas-works,  are 
treated  as  follows  : — The  liquor  is  first 
rectified  by  distillation  from  a  wagon- 
shaped  wrought-iron  boiler,  into  a  square 
cistern  of  iron  lined  with  lead.  4500  lbs. 
of  sulphuric  acid,  of  specific  gravity 
1-625,  are  then  slowly  added  to  the 
somewhat  concentrated  distilled  water  of 
ammonia.  The  produce  is  2400  gallons 
of  sulphate  of  ammonia,  slightly  acidu- 
lous, of  specific  gravity  1*150,  being  of 
such  strength  as  to  deposit  few  crystals 
upon  the  sides  of  the  lead-lined  iron 
tank  in  which  the  saline  combination  is 
made.  It  is  decomposed  by  common 
salt. 

From  the  7200  gallons  of  the  first  crude 
liquor,  900  gallons  of  tar  are  got  by  sub- 
sidence, and  200  gallons  of  petroleum  are 
skimmed  off  the  surface.  The  tar  is  con- 
verted, by  a  moderate  boiling  in  iron 
pans,  into  good  pitch. 

SALEP,  or  SALOUP,  is  the  name  of 
the  dried  tuberous  roots  of  the  Orchis, 
imported  from  Persia  and  Asia  Minor, 
which  are  the  product  of  a  great  many 
species  of  the  plant,  but  especially  of  the 
Orchis  mascula.  Salep  occurs  in  com- 
merce in  small  oval  grains,  of  a  whitish- 
yellow  color,  at  times  semi-transparent, 
of  a  horny  aspect,  very  hard,  with  a  faint 
peculiar  smell,  and  a  taste  like  that  of 
gum  tragacanth,  but  slightly  saline. 
These  .are  composed  almost  entirely  of 
starchy  matter,  well  adapted  for  making  a 
thick  pap  with  water  or  milk,  and  are 
hence  in  great  repute  in  the  Levant,  as 
restorers  of  the  animal  forces.  Their 
aphrodisiacal  properties  are  apocryphal. 
It  the  largest  roots  of  the  Orchis  mascula 
of  our  own  country  were  cleaned,  scrap- 
ed, steeped  for  a  short  time  in  hot,  and 
then  for  a  few  minutes  in  boiling  water, 


to  extract  their  rank  flavor,  afterward, 
suspended  upon  strings  to  dry  in  the  air 
they  would  afford  as  nourishing  and  pal- 
atable an  article  as  the  Turkey  saloup, 
and  at  a  vastly  lower  price. 

SALICINE,  is  a  febrifuge  substance, 
which  may  be  obtained  in  white  pearly 
crystals  from  the  bark  of  the  white  wil- 
low (Salix  alba),  of  the  aspen  tree  (Salix 
helis),  as  also  of  some  other  willows,  and 
some  poplars.    It  has  a  very  bitter  taste. 

SAL  PRUNELLA,  is  fused  nitre  cast 
into  cakes  or  balls. 

SAL  VOLATILE,  is  sesquicarbonate 
of  ammonia. 

SALT,  EPSOM,  is  sulphate  of  magne- 
sia. 

SALT,  MICROCOSMIC,  is  the  triple 
phosphate  of  soda  and  ammonia. 

SALT  OF  AMBER,  is  succinic  acid. 

SALT  OF  LEMONS,  is  citric  acid. 

SALT  OF  SATURN  is  acetate  of  lead. 

SALT  OF  SODA,  is  carbonate  of 
soda. 

SALT  OF  SORREL,  is  bi-oxalate  of 
potassa. 

SALT  OF  TARTAR,  is  carbonate  of 
potassa. 

SALT  OF  VITRIOL,  is  sulphate  of 
zinc. 

SALT  PERLATE,  is  phosphate  of 
soda. 

SALTPETRE,  is  nitre,  or  nitrate  of 
potassa 

SALT,  SEDATIVE,  is  boracic  acid. 

SALT.  This  term,  though  in  ordinary 
language  limited  to  common  salt,  or  sea 
salt,  is  applied  in  chemistry  to  all  combi- 
nations of  acids  with  alkaline  or  salifiable 
bases.  The  term  has  also  been  extended 
to  certain  binary  combinations  of  chlo- 
rine, iodine,  bromine,  and  fluorine  with 
the  metals ;  and  these  have  been  called 
haloid  salts  (from  d\s,  sea  salt,  and  etSos, 
form),  inasmuch  as  modern  chemistry 
has  taught  us  that  sea  salt  belongs  to  this 
class.  Certain  definite  combinations  of 
sulphurets  with  each  other  have  of  late 
been  called  sulphur  salts  ;  but  the  former 
appellation  of  double  sulphurets  is,  per- 
haps, more  properly  applicable  to  such 
compounds. 

Sea  salt  is  a  compound  of  1  equivalent 
of  sodium  =  24,  and  1  of  chlorine  =  36; 
its  equivalent,  therefore,  is  (24  +  36)=  60: 
and  it  is  a  chloride  of  soda. 

The  nomenclature  of  salts  has  reference 
to  the  acids  which  they  contain  ;  sulphates, 
nitrates,  carbonates,  &c,  implying  salts  of 
the  sulphuric,  nitric,  and  carbonic  acids. 
The  termination  ate  implies  the  maximum 
of  oxygen  in  the  acids,  and  itc  the  mini- 


548 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sal 


mum  :  thus  the  salts  of  sulphurous  and 
nitrous  acids  are  called  sulphites  and 
nitrites.  When  salts  contain  1  equivalent 
of  acid  and  1  of  base,  they  are  called 
neutral  salts  ;  where  1  equivalent  of  acid 
is  combined  with  2  of  base,  they  are 
termed  basic  salts,  subsalts  or  disalts  /  and 
where  there  are  2  equivalents  of  acid  and 
1  of  base,  the  salt  is  a  supersalt  or  bisalt. 
Thus,  the  terms  subacetate  and  diacetate 
of  lead  are  synonymous  ;  so  arc  supercar 
bonate  and  bicarbonate  of  potash.  Many 
salts  are  hydrous  •  that  is,  they  contain  a 
definite  proportion  of  water  of  crystalli- 
zation ;  others  are  destitute  of  "water, 
and  are  dry  or  anhydrous  salts.  Some 
salts  attract  moisture  when  exposed  to 
air,  and  are  said  to  be  deliquese  •  others 
suffer  their  water  to  escape  and  become 
opaque,  or  pulverulent:  these  are  called 
efflorescent  salts. 

Salt  is,  next  to  bread,  the  most  impor- 
tant necessary  of  life.  It  is  one  of  the 
most  important  British  minerals,  and  is 
procured  in  great  quantities,  both  from 
iossil  beds  and  brine  springs,  in  Cheshire 
and  Worcestershire.  Previously  to  the 
discovery  of  the  fossil  beds  during  the 
16th  century,  and  subsequently,  a  good 
deal  of  salt  continued  to  be  made  by  the 
evaporation  of  sea  water  in  salt  pans,  at 
Lymington  and  many  other  places ;  but 
the  works  at  these  places  are  now  all  but 
abandoned ;  while  not  only  has  the  quali- 
ty of  the  article  in  question  become  great- 
ly improved,  but,  instead  of  being  im- 
ported as  formerly,  it  is  now  largely 
exported.  The  consumption  of  Great 
Britain  only,  exclusive  of  Ireland,  a- 
mounts  to  "about  180,000  tons  ;  and  the 
foreign  exports  to  about  300,000  tons  per 
year,  of  which  the  United  States,  Canada, 
the  Low  Countries,  Russia,  Prussia,  and 
Denmark  are  the  chief  consumers. 

The  geological  position  of  rock-salt  is 
between  the  coal  formation  and  the  lias. 
The  great  rock-salt  formation  of  England 
occurs  within  the  red  marl,  or  new  red 
sandstone,  the  bunter-sandstein  of  the 
Germans,  so  called,  because  its  colors  vary 
from  red  to  salmon  and  chocolate.  This 
mineral  stratum  frequently  presents 
streaks  of  light  blue,  verdigris,  buff,  or 
cream  color;  and  is  chiefly  remarkable 
for  containing  considerable  masses  or 
beds  of  gypsum.  At  Northwich,  in  the 
vale  of  Weaver,  the  rock  salt  consists  of 
two  beds,  together  not  less  than  60  feet 
*hick,  which  are  supposed  to  constitute 
large  insulated  masses,  about  a  mile  and 
a  half  long,  and  nearly  1300  yards  broad. 
There  are  other  deposits  of  rock  salt  in 


the  same  valley,  but  of  inferior  impor- 
tance. The  uppermost  bed  occurs  at  75 
feet  beneath  the  surface,  and  is  covered 
with  many  layers  of  indurated  red,  blue, 
and  brown  clay,  interstratified  more  or 
less  with  sulphate  of  lime,  and  inter- 
spersed with  argillaceous  marl.  The 
second  bed  of  rock-salt  lies  314  feet  be- 
low the  first,  being  separated  from  it  by 
layers  of  indurated  clay,  with  veins  of 
rock-salt  running  through  them.  The 
lowest  bed  of  salt  was  excavated  to  a 
depth  of  110  feet,  several  years  ago. 

The  beds  or  masses  of  rock-salt  are  oc- 
casionally so  thick,  that  they  have  not 
been  yet  bored  through,  though  mined 
for  many  centuries.  This  is  the  case 
with  the  immense  mass  of  Wieliczka, 
and  the  lower  bed  at  Northwich.  But  in 
ordinary  cases,  this  thickness  varies  from 
an  inch  or  two  to  12  or  15  yards.  When 
the  strata  are  thin,  they  are  usually 
numerous ;  but  the  beds,  layers,  or 
masses  never  exhibit  throughout  a  great 
extent  any  more  than  an  illusory  appear- 
ance of  parallelism ;  for  when  they  are 
explored  at  several  points,  enlargements 
are  observed,  and  such  diminutions  as 
cause  the  salt  to  disappear  sometimes 
altogether.  This  mineral  is  not  deposit- 
ed, therefore,  in  a  geological  stratum,  but 
rather  in  lenticular  masses,  of  very  varia- 
ble extent  and  thickness,  placed  along- 
side of  each  other  at  unequal  distances, 
and  interposed  between  the  courses  of 
other  formations. 

Sometimes  the  rock  salt  is  disseminat- 
ed in  small  masses  or  little  veins  among 
the  calcareous  and  argillaceous  marls 
which  accompany  or  overlie  the  greater 
deposits.  Bitumen,  in  small  particles, 
hardly  visible,  but  distinguishable  by  the 
smell,  occurs  in  all  the  minerals  of  the 
saliferous  system. 

It  has  been  remarked,  that  the  plants 
which  grow  generally  on  the  sea  shores, 
such  as  the  Triglochinum  muritimum, 
the  Salicornia,  the  Salsola  kali,  the  Aster 
trifolium,  or  farewell  to  summer,  the 
G\aux  maritima,  &c,  occur  also  in  the 
neighborhood  of  salt  mines  and  salt 
springs,  even  of  those  which  are  most 
deeply  buried  beneath  tlfe-  surface. 

The  interior  of  rock-salt  mines,  after 
digging  through  the  strata  of  clay  marl, 
&c.  is  extremely  dry ;  so  that  the  dust 
produced  in  the  workings  becomes  an  an- 
noyance to  the  miners,  though  in  other 
respects  the  excavations  are  not  at  all  in- 
salubrious. 

Salt  springs  occur  nearly  in  the  same 
circumstances,  and  in  the  same  geological 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


549 


formation  as  the  salt-rock.  It  has  heen 
noticed,  that  salt  springs  issue,  in  general, 
from  the  upper  portion  of  the  saliferous 
strata,  principally  from  the  saline  clay 
marls.  Cases  however  occur,  where  the 
salt  springs  are  not  accompanied  by  rock- 
sait,  and  where  the  whole  saline  matter 
is  derived  from  the  marls  themselves, 
which  thus  constitute  the  only  saliferous 
beds. 

The  salt  used  in  the  United  States,  is 
derived  here  by  importation  from  Liver- 
pool, or  from  Turks  Island,  or  obtained 
from  the  salines  of  Onondaga,  the  waters 
of  which  are  evaporated  to  dryness.  That 
of  Turks  Island  is  chiefly  produced  by 
solar  evaporation.  In  Key  West,  Florida, 
the  manufacture  of  salt  by  solar  evapora- 
tion is  carried  on  on  a  small  scale,  that  is 
from  30  to  40  thousand  bushels  yearly. 
This  salt  is  of  a  superior  quality  for  pack- 
ing meat.  The  manufacture  commenced 
in  1845.  The  salt  made  in  the  State  of 
New  York,  is  from  the  salines  of  Onon- 
daga, the  waters  of  which  furnish  abun- 
dance of  salt,  as  much  as  from  16  to  25 
ozs.  to  the  gallon  of  water.  The  State 
imposes  a  tax  of  12£  cents  per  bushel  on 
all  salt  made.  Besides  muriate  of  soda 
the  waters  contain  chloride,  calcium,  sul- 
phates of  lime  and  magnesia,  and  oxide  of 
iron.  Some  years  back  there  were  an- 
nually produced  half  a  million  bushels 
of  salt  per  year,  the  price  25  cents  per 
bushel.  The  salt  is  obtained  by  evapo- 
rating the  brine  down  to  the  point  of 
crystallization  and  separating  the  impuri- 
ties. 

_  The  State  Superintendent  of  the  Sa- 
lines of  Onondaga,  reports  as  follows : 
"  We  have  manufactured  this  year  (1849) 
very  nearly  five  million  bushels  of  salt 
already,  and  shall  exceed  that  figure  some- 
what at  the  close  of  the  year,  say  300,000 
bushels  over  last  year.  (The  bushel  is 
reckoned  at  26  lbs.)  In  regard  to  the 
consumption  of  fuel,  I  cannot"  say  much 
that  will  be  new  to  you.  No  improve- 
ment has  been  made,  perhaps,  since  you 
were  here." 

The  importance  of  these  Salines  may  be 
inferred  from  the  fact,  that  in  the  year 
1836  the  whole  import  of  salt  into"  the 
ports  of  the  United  States  amounted  to 
5,088,666  bushels,  of  56  lbs  each,  being 
but  a  trifle  more  than  this  year's  produc- 
tion of  the  Salines  of  Onondaga. 

With  regard  to  the  use  of  Anthracite 
coal,  as  fuel  for  making  salt,  the  experi- 
ment is  said  not  to  have  been  successful, 
and  that  the  gentleman  who  made  the 
trial  has  since  substituted  wood  for  coal. 


Heretofore  one  cord  of  wood  was  used 
in  making  forty  bushels  of  salt.  At  that 
rate,  125,000  cords  of  wood  are  required 
for  the  evaporation  of  brine  for  5.000,000 
bushels  of  salt.  About  forty  gallons  of 
brine  make  a  bushel  of  salt,  therefore 
requiring  two  hundred  millions  of  gallons 
of  brine  to  be  raised  from  the  wells,  to 
produce  the  quantity.  By  the  Salometer, 
the  brine  tests  about  74° — 0  being  the 
mark  for  fresh  water,  and  100°  for  brine 
of  full  saturation. 

"  From  very  minute  and  extensive  ex- 
aminations of  the  Salines  of  Onondaga, 
and  from  my  own  experience  in  the 
evaporation  of  fluids  by  heat,  my  opinion 
is  clear,  that  25,000  cords  of  wooa  may 
be  made  to  do  the  work  heretofore  per- 
formed by  125,000  cords." 

SALTPETRE,  is  a  natural  compound 
of  potash  and  nitric  acid.  It  abounds  in 
soils  where  animal  substances  and  lime 
are  in  contact,  and  these  being  lixiviated, 
decanted,  and  evaporated  to  dryness, 
crystals  of  saltpetre  are  formed.  Some- 
times they  are  redissolved,  and  evapo- 
rated a  second  time. 

The  chief  of  the  saltpetre  used  in  this 
country  comes  from  the  East  Indies, 
where  at  certain  seasons  of  the  year,  it  is 
found  deposited  on  the  surface  of  the  soil, 
and  though  swept  off  once  or  twice  a 
week,  it  is  as  often  renewed.  At  Apulia, 
near  Naples,  there  is  a  bed  containing  40 
per  cent. ;  and  in  Switzerland  the  farmers 
extract  it  in  abundance  from  the  earth, 
under  the  stalls  of  their  cattle  j  for  the 
urine  of  cattle  contains  potash  m  abun- 
dance. In  Spain  there  is  enough  to  sup- 
ply all  Europe. 

It  appears,  in  every  case,  to  be  a  con- 
solidation of  the  nitrogen  of  the  atmo- 
sphere, which  consolidates,  in  this  way, 
just  as  oxygen  consolidates  in  the  pro- 
duction of  rust  and  oxides  of  all  kinds. 
Thus  considered,  the  consolidation  of 
one  promotes  the  consolidation  of  the 
other,  since  they  are  always  present  in 
the  air  as  1  oxygen  and  3*5  nitrogen. 

Saltpetre-earth  absorbs  a  little  mois- 
ture at  night,  and  appears  like  a  black 
foot-dust  at  the  bottom  of  old  walls,  or 
on  the  streets  of  populous  or  old  villages. 

It  does  not  differ  in  appearance  from 
that  which  yields  salt  or  soda  ;  and  in- 
deed, one  village,  or  one  street,  frequently 
contains  the  three  salts. 

The  most  profitable  way  of  preparing 
it  is,  to  evaporate  it  in  shallow  basins  of 
mortar.  The  earth  is  swept  up  every 
other  day  and  contains  about  one-fifth 
of  crude  saltpetre.    After  the  saltpetre 


550 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[SAN 


is  extracted,  the  earth  is  heaped  up  till 
the  rains  are  over,  and  then  spread  out, 
and  in  a  year  or  two  it  yields  again. 

About  two  gallons  "of  saltpetre-earth 
is  collected  at  the  foot  of  each  yard  of 
wall.  The  saltpetre  gained  from  black 
cotton  ground  contains  more  common 
salt  than  that  from  common  earth.  The 
pans  of  mortar  are  filled  about  four  in- 
ches deep,  about  half  is  evaporated  In 
four  or  six  days,  and  the  saltpetre  begins 
to  crystallize.  The  first  day's  product  is 
the  purest;  the  second  day's  contains 
about  halt  common  salt :  the  third  day's 
contains  scarcely  a  quarter  of  saltpetre. 

Saltpetre  is  refined  by  boiling ;  adding 
soap,  milk,  eggs,  and  twigs  of  euphorbia 
tirucalli :  and  single  refined  saltpetre  still 
contains  about  a  quarter  of  common  salt. 
Bengal  saltpetre  is  browner  than  that  of 
the  coast. 

If  saltpetre  is  kept  or  prepared  in  any 
apartment,  it  is  difficult,  in  India,  to 
prevent  the  destruction  of  the  walls,  by 
the  continual  production  of  the  salt. 

Calcareous  earths,  impregnated  with 
saltpetre,  are  found  in  caverns  in  lime- 
stone, in  various  places.  The  saltpetre 
earth  of  Georgia,  contains  both  the  ni- 
trate of  potash  and  that  of  lime ;  but  the 
latter  is  changed  into  saltpetre,  by  ad- 
ding wood-ashes ;  one  bushel  of  earth 
yields  frcm  three  to  ten  pounds  of  salt- 
petre. Kentucky  saltpetre-earth  is  simi- 
llar;  it  is  washed,  and  the  ley  passed 
through  wood-ashes,  when  a  bushel 
yields  from  one  to  two  pounds  of  salt- 
petre. 

Similar  earths  are  found  at  Molfetta, 
Naples,  Hungary,  and  various  places. 

Kentucky  rock-ore  is  a  sand-stone, 
which,  when  broken  to  fragments,  and 
thrown  into  boiling-water,  soon  falls  into 
sand,  and  the  liquor  strained  from  it 
yields,  by  crystallization,  from  ten  to 
twenty  pounds  of  nitre  from  each  bushel 
of  stone.  This  nitre  contains  little  or  no 
nitrate  of  lime,  and  is  considered  better 
for  gunpowder  than  that  obtained  from 
Kentucky  nitre-earth.  Masses  of  salt- 
petre, of  several  pounds  weight,  are 
sometimes  found  in  the  fissures  of  this 
sand-stone,  accompanied  by  masses  of  a 
black  bituminous  substance.  Similar 
sand-stones  are  found  in  South  Africa. 

The  saltpetre  formerly  used  in  Eng- 
land was  extracted  from  the  mortar  of 
old  buildings,  as  it  still  is  in  France  and 
Prussia.  The  mark,  by  which  saltpetre- 
workers  know  good  mortar  for  their  pur- 
pose is,  that  it  tastes  acrid  and  salt,  when 
applied  to  the  tongue ;  but  to  this  it  may 


be  also  added,  that  it  ought  to  be  of  a 
grayish  colour,  and  such  as,  when  pow- 
dered and  sprinkled  upon  burning  char- 
coal, yields  sparks  ;  and,  the  more  sparks 
it  gives,  the  better  it  is  for  the  purpose. 
Another  characteristic  is,  that  these  well- 
impregnated  mortars  have  a  certain 
unctuosity  or  fattiness  to  the  touch, 
which  other  kinds  have  not. 

The  best  of  all  kinds  of  mortar,  for 
saltpetre  work,  is  such  as  is  had  from 
the  ruins  of  old  buildings  in  a  low  situa- 
tion, and  out  of  the  way  of  much  sun- 
shine, where  there  has  been  no  great 
quantity  of  fire  kept,  and  especially  such 
as  has  served  for  the  mortar  of  the  walls 
of  stables.  In  Prussia,  the  rubbish  of 
old  buildings  is  built  up  in  thin  long 
walls,  sheltered  from  the  weather  by 
straw  coverings,  and  sprinkled  with 
urine  of  all  kinds,  for  the  purpose  of 
generating  this  salt. 

A  clear  dry  frosty  air  is  particularly 
favorable  to  the  production  of  saltpetre, 
and  it  disappears  in  snow-storms. 

Napier  detected  impurities  in  nitre, 
by  dropping  a  strong  solution  of  sugar 
of  lead  into  a  phial  of  distilled  water, 
saturated  with  saltpetre;  if  it  retained 
any  considerable  portion  of  marine-salt 
or  magnesia,  it  assumed  a  turbid  milky 
appearance.  The  best  is  Kussian;  yet 
the  manufacturers  seldom  refine  their 
nitre  more  than  twice  ;  and  it  has  been 
found  that  their  saltpetre  contains  a  con- 
siderable portion  of  marine-salt  and  mag- 
nesia. There  is  reason  to  believe,  that 
powder,  made  with  saltpetre  oftener  than 
tour  times  refined,  is  of  inferior  strength. 

The  goodness  of  saltpetre  is  measured 
by  the  angle  at  which  light  is  refracted 
in  passing  through  it.  As  the  angle  is 
less,  the  quality  is  better.  This  angle 
varies  very  considerably.  An  angle  of 
5°  is  called  par,  and,  the  variations  from 
it  are  made  up  by  increasing  or  diminish- 
ing, not  the  price,  but  the  quantity ;  for 
every  degree  by  which  its  angle  of  re- 
fraction exceeds  5,  1  per  cent,  in  weight 
is  allowed,  and  the  contrary. 

SAND  is  the  name  given  to  any  mine- 
ral substance  in  a  hard  granular 'or  pul- 
verulent form,  whether  strewed  upon 
the  surface  of  the  ground,  found  in 
strata  at  a  certain  depth,  forming  the 
beds  of  rivers,  or  the  shores  of  the  sea. 
The  silicious  sands  seem  to  be  either 
original  crystalline  formations,  like  the 
sand  of  Neuilly,  in  six-sided  prisms, 
terminated  by  two  six-sided  pyramids, 
or  the  debris  of  granitic,  schistose, 
quartzosc,    or  other   primitive    crystal- 


sap] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


551 


line  rocks,  and  are  abundantly  distribut- 
ed over  the  globe ;  as  in  the  immense 
plains  known  under  the  names  of  downs, 
deserts,  steppes,  landes,  dbc,  which,  in 
Africa,  Asia,  Europe,  and  America,  are 
entirely  covered  with  loose  sterile  sand. 
Valuable  metallic  ores,  those  of  gold,  pla- 
tinum, tin,  copper,  iron,  titanium,  often 
occur  in  the  form  of  sand,  or  mixed  with 
that  earthy  substance.  Pure  silicious 
sands  arc  very  valuable  for  the  manufac- 
ture of  glass,  for  making  mortars,  filters, 
ameliorating  dense  clay  soils,  and  many 
other  purposes.  Its  chief  uses  are  in  com- 
positions for  pottery  and  glass,  and 
some  sands  are  more  and  some  less  fusi- 
ble, according  to  the  various  stones  from 
which  they  may  have  originated.  The 
size  of  the  particles  is  of  importance  in 
these  works.  It  is  the  wearing  down  of 
rocks  by  attrition,  during  the  sub-marine 
state,  or  the  advance  and  retreat  of  the 
ocean. 

Sand  drifts,  or  floods,  are  arrested  by 
planting  marum,  or  sea-bent,  or  the 
arundo  arenania,  and  other  plants,  that 
take  root  in  sand. 

Sandstone  is,  in  most  cases,  compos- 
ed chiefly  of  fine  grains  of  quartz,  united 
by  a  cement,  which  is  nearly  or  quite  in- 
visible. The  cement  is  variable,  and  may 
be  calcareous  or  marly,  argillaceous,  or 
argillo-ferruginous,  or  even  silicious. 
When  silicious,  sandstone  resembles 
quartz.  Some  varieties  are  so  hard  as  to 
give  fire  with  steel,  while  others  are  fri- 
able, and  may  be  reduced  to  powder  by 
the  fingers.  Some  have  a  slaty  struc- 
ture, arising  from  scattered  and 'insulat- 
ed plates  of  mica,  and  are  often  called 
sandstone  slate.  Some  sandstones  con- 
tain grains  of  feldspar,  flint,  and  silicious 
slate  or  plates  of  mica.  The  mica  is  in 
considerable  quantities  in  those  friable 
sandstones  which  accompany  coal.  Some 
are  so  ferruginous  as  to  form  a  valuable 
ore  of  iron,'  containing  eitjier  an  oxide  or 
the  carbonate  of  iron.  Red  sandstone 
is  sometimes  connected  with  coal.  In 
the  older  formation  it  sometimes  con- 
tains metallic  substances  disseminated 
through  the  mass,  or  in  beds  or  veins. 
Various  organic  remains  occur  in  sand- 
stone, among  which  are  reeds,  impres- 
sions of  leaves,  trunks  of  trees,  and 
shells,  both  fluviatile  and  marine.  In 
some  of  its  varieties  it  is  often  known 
by  the  name  of  freestone,  and  is  em- 
ployed as  a  building-stone.  In  most 
cases,  it  may  be  cut  equally  well  in  all 
directions  ;  but  some  varieties  naturally 
divide    into    prismatic    masses.     Some 


compounds  are  used  as  mill-stones. 
When  porous,  it  is  employed  for  filter- 
ing water.  Some  are  even  used  for  whet- 
stones. 

SANDAL  or  RED  SAUNDERS  WOOD 
is  the  wood  of  the  Pterocapus  santalinu-s, 
a  tree  which  grows  in  Ceylon,  and  on  the 
coast  of  'Coromandel.  The  old  wood  is 
preferred  by  dyers.  Its  coloring  matter 
is  of  a  resinous  nature :  and  is,  there- 
fore, quite  soluble  in  alcohol,  essential 
oils,  and  alkaline  leys  ;  but  sparingly  in 
boiling  water,  and  hardly  if  at  all  in  cold 
water.  The  coloring  matter  which  is 
obtained  by  evaporating  the  alcholic  in- 
fusion to  dryness,  has  been  called  santa- 
line  ;  it  is  a  red  resin,  which  is  fusible  at 
212°  F.  It  may  also  be  obtained  by  di- 
gesting the  rasped  sandal  wood  in  water 
of  ammonia,  and  afterwards  saturating 
the  ammonia  with  an  acid.  The  santaline 
falls,  and  the  supernatant  liquor,  which 
is  yellow  by  transmitted,  appears  blue  by 
reflected  light.  Its  spirituous  solution 
affords  a  fine  purple  precipitate  with  the 
protochloride  of  tin,  and  a  violet  one 
with  the  salts  of  lead.  Santaline  is  very 
soluble  in  acetic  acid,  and  the  solution 
forms  permanent  stains  upon  the  skin. 

SANDARACH,  is  a  peculiar  resin- 
ous substance,  the  product  of  the  Thuya 
articulata,  a  small  tree  of  the  coniferous 
family,  which  grows  in  the  northern 
parts  of  Africa,  especially  round  Mount 
Atlas. 

The  resin  comes  to  us  in  pale  yellow, 
transparent,  brittle,  small  tears,  of  a 
spherical  or  cylindrical  shape.  It  has  a 
faint  aromatic  smell,  does  not  soften,  but 
breaks  between  the  teeth,  fuses  readily 
with  heat  and  has  a  specific  gravity  of 
from  1-05  to  1-09.  It  contains  three  dif- 
ferent resins;  one  soluble  in  spirit  of 
wine,  somewhat  resembling  pinic  acid 
(see  Turpentine)  ;  one  not  soluble  in 
that  menstruum ;  and  a  third,  soluble 
only  in  alcohol  of  90  per  cent.  It  is  used 
as  pounce-powder  ,for  strewing  over  pa- 
per erasures,  as  incense,  and  in  var- 
nishes. 

SAP  GREEN.  The  inspissated  juice 
of  the  berries  of  the  buckthorn. 

SAPAN  WOOD  is  a  species  of 
the  Cmsalpinia  genus,  to  which  Bra- 
zil wood  belongs.  It  is  so  called  by 
the  French,  because  it  comes  to  them 
from  Japan,  which  they  corruptly  pro- 
nounce Sapan.  As  all  the  species  of  this 
tree  are  natives  of  the  East  Indies  or  the 
New  World,  one  would  imagine  that 
they  could  not  have  been  used  as  dye- 
stuffs  in  Europe  before  the  16th  century. 


552 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SCA 


Yet  the  author  of  the  article  "Brazil,"  in  j 
Rees'  Cyclopaedia,  and  Mr.  Southey,   in  ; 
his  History  of  Brazil,    say   that  Jirazil  ; 
wood  is  mentioned  nearly  one   hundred  I 
years  before  the  discoveries  of  Columbus 
and  Vasco  de  Gama,  by  Chaucer,  who  I 
died  in  1400;  that  it  was  known  many 
ages  before  this  time  ;  and   that  it  gave 
the  name  to  the  country,  instead  of  the 
country  giving  the  name  to  the  wood,  as 
It  stated  by  Berthollet  and  other  writers 
on  dyeing.'    The  Casalpinia  sappan,  be- 
ing  a   native  of  the   Coromandel  coast, 
may  possibly  have  been  transported  along 
with  other   Malabar  merchandise  to  the  | 
Mediterranean  marts  in  the  middle  ages. 

SARD.     {See  Lapidary.) 

S  ARCOCOLL,  a  gum,  sold  in  globules, 
smelling  like  aniseed.  It  yields  oxalic 
acid,  and  a  variety  of  liquorice ;  in  nitric 
acid  it  is  converted  into  tannin. 

SASH.  In  Architecture,  a  piece  of 
framing  for  holding  the  squares  of  glass 
in  a  window.  It  is  of  two  sorts — viz., 
that  called  the  French  sash,  which  is 
hung  like  a  door  to  the  sash-frame ;  and 
that  in  which  it  moves  vertically  from  I 
being  balanced  by  a  weight  on  each  side,  ; 
to  which  it  is  attached  by  lines  running 
over  pulleys  at  the  top  of  the  sash-frame. 
"When  in  a  window  where  both  the  upper 
and  lower  sashes  are  moveable,  the  sashes 
are  said  to  be  double  hung,  and  single 
hung  when  only  one  of  them  moves. 

SASH  SUPPORTER,  or  SASH  STOP-  ; 
PER. — A  substitute  for  weights  and  pul- 
leys,  in  supporting1  window  sashes.  It  is  ! 
of  various  constructions,  sometimes  con- 
sisting of  a  roller  of  elastic  material, 
whose  axle  works  in  bearings  in  the  win- 
dow frame,  and  whose  periphery  presses 
against  the  sash.  Sometimes  it  is  a  roller 
of  metal,  placed  in  the  edge  of  the  sash,  ; 
with  a  spring  at  the  back  of  it,  to  press 
it  out  against  the  inside  of  the  frame. 
Another  form  consists  of  a  spring  bolt, 
placed  in  the  sash,  and  capable  of  shoot- 
ing into  any  one  of  a  series  of  holes  in 
the  inside  of  the  frame,  to  hold  the  sash 
at  different  heights.  This  form  serves 
also  as  a  fastening  for  the  window,  when 
closed,  and  is  much  used  in  rail-road 
cars,  where  the  jarring  prevents  any  de- 
vice, which  is  merely  a  balance,  or  which 
depends  upon  friction  produced  by  an 
elastic  pressure,  from  being  effective. 
There  are  many  other  forms,  some  of 
which  are  the  subjects  of  Patents,  but  for 
house  windows,  the  common  sash  weight, 
line,  and  pulley  is  to  be  preferred  to  most 
of  them. 

SATIN ;    a   soft  closely-woven   silk. 


with  a  glossy  surface.  In  the  manufac- 
ture of  other  silken  stuffs,  each  half  of 
the  warp  is  raised  alternately ;  but,  in 
weaving  satin,  the  workman  only  raises 
the  fifth  or  the  eighth  part  of  the  warp  ; 
thus  the  woof  is  hidden  beneath  the 
warp,  which,  presenting  an  even,  close, 
and  smooth  surface,  is  capable  of  reflect- 
ing the  rays  of  light.  In  this  way  satin 
acquires  that  lustre  and  brilliancy  which 
distinguishes  it  from  most  other  kinds  of 
silks. 

SAWS,  are  wedges  to  tear  their  way 
through  an  obstacle.  They  are  recipro- 
cating or  circular.  The  former  are  well 
known  as  hand-saws,  or  reciprocating 
ones,  such  as  are  seen  in  saw  pits.  The 
circular,  as  better  adapted  to  power,  and 
more  precise  and  rapid  in  their  action, 
are  becoming  general.  They  were  in- 
vented in  Holland,  about  17*80,  and  are 
a  great  acquisition.  The  machine  which 
turns  the  saw  draws  the  piece  to  the 
work,  which  is  so  accurate  that  an  inch 
thick  of  certain  woods  may  be  divided 
into  twenty  uniform  sheets,  allowing  for 
waste. 

SCAGLIOLA.  In  Architecture,  a  com- 
position ,  sometimes  called  also  Mischia, 
trom  the  mixture  of  colors  employed  in 
it,  being  made  to  imitate  marble.  The 
Florentines  claim  the  invention  of  this 
art,  but  it  had  been  practised  in  Lom- 
bardy  previous  to  its  introduction  at 
Florence.  Lanza  says  that  it  was  invented 
by  Guido  Sassi,  who  died  in  1649,  at  the 
age  of  65,  at  Carpis,  in  the  state  of  Mo- 
dena,  and  that  he  commenced  by  exe- 
cuting cornices  and  other  members  of  ar- 
chitecture which  had  all  the  appearance 
of  the  finest  marbles  ;  whereas  its  intro- 
duction at  Florence  was  not  till  the  mid- 
dle of  the  18th  century.  Scagliola  is 
composed  of  gypsum  or  sulphate  of  lime, 
calcined  and  reduced  to  a  fine  powder, 
witl^  the  addition  of  which  to  water  a  fine 
paste  is  made.  When  columns  are  made 
with  this  composition,  a  frame  or  cradle 
is  first  formed,  which  is  lathed  round  and 
coated  with  lime  and  hair,  raised  up  in 
some  parts  with  small  projections.  On 
this,  when  dry,  is  laid  a  composition 
consisting  of  pure  gypsum,  calcined  and 
passed  through  a  sieve,  and,  as  wanted, 
mixed  with  glue  or  isinglass  ;  it  is  float- 
ed with  wooden  moulds  of  the  proper 
form,  during  which  operation  the  colors, 
by  which  the  imitation  is  obtained,  are 
put  on.  When  this  is  set  the  work  is 
smoothed  with  pumice-stone  with  one 
hand  of  the  workman,  while  the  other  is 
employed  in  washing  it  with  a  sponge 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


553 


and  water.  It  is  then  polished  with  trip- 
oli,  charcoal,  and  a  piece  of  fine  linen, 
and  afterwards  with  a  piece  of  felt 
dipped  in  oil  of  tripoli,  and  finished  off 
with  pure  oil  laid  on  with  cotton  wool. 

SCALE.  In  mensuration,  a  line  or  rule 
of  a  definite  length,  divided  into  a  given 
number  of  equal  parts,  and  used  for  the 
purpose  of  measuring  other  linear  mag- 
nitudes. It  becomes  a  standard  scale 
when  all  its  divisions  have  been  exam- 
ined and  compared  with  some  standard 
measure.  The  scales  of  thermometers 
are  graduated  from  some  arbitrary  point 
or  zero  (as  that  wliich  indicates  the  tem- 
perature of  freezing  water),  from  which 
the  heat  is  counted  upwards  or  down- 
wards in  degrees,  which  are  also  arbi- 
trary. 

The  term  scale  is  also  applied  to  a  mathe- 
matical instrument,  consisting  of  an  as- 
semblage of  lines  and  figures  engraved 
on  a  plane  rule,  by  means  of  which  cer- 
tain proportional  quantities  or  arithmeti- 
cal results  are  obtained  by  inspection. 
Of  these  the  principal  are  the  plane  scale, 
the  diagonal  scale,  Grunter>s  scale,  &c. 

SCALES,  are  measures  of  the  down- 
ward tendency,  centripetal  force,  or 
weight  of  bodies.  A  body  is  put  in  one 
scale,  whose  weight  is  known,  and  the 
arms  being  truly  equal,  a  body  of  un- 
known weight  balances  the  known 
weight.  When  well  made,  they  are  true 
to  the  50000th  of  the  body  weighed  ; 
but  the  friction  of  large  scales  renders  it 
ineligible  to  weigh  ounces  or  grains  in 
them  ;  the  friction  on  a  hundred  weight 
is  the  third  of  an  ounce.  (See  Balance.) 
SCANTLING.  In  architecture,  the 
measures  of  breadth  and  thickness  of  a 
piece  of  timber  or  other  material.  It 
is  also  the  name  of  a  piece  of  timber 
when  under  five  inches  square. 

Scantling.  In  naval  architecture, 
the  scale  or  dimensions  of  breadth  and 
thickness  of  the  timbers.  Thus  two 
ships  of  different  sizes  may  have  the 
same  scantling. 

SCAKLET  DYE.  M.  Kobiquet  has 
given  the  following  prescription  for  ma- 
king a  printing  scarlet,  for  well- whitened 
woollen  cloth. 

Boil  a  pound  of  pulverized  cochineal 
in  four  pints  of  water  down  to  two  pints, 
and  pass  the  decoction  through  a  sieve. 
Bepeat  the  boiling  three  times  upon  the 
residuum,  mix  the  eight  pints  or  decoc- 
tion, thicken  them  properly  with  two 
pounds  of  starch,  and  boil  into  a  paste. 
Let  it  cool  down  to  104°  F.,  then  add  four 
ounces  of  the  subjoined  solution  of  tin, 
24 


and  two  ounces  of  ordinary  salt  of  tin 
(muriate).  When  a  ponceau  red  is  want- 
ed, two  ounces  of  pounded  curcuma 
(turmeric)  should  be  added. 

The  solution  of  tin  above  prescribed, 
is  made  by  taking — one  ounce  of  nitric 
acid,  of  specific  gravity  86°  B,  =  1-33; 
one  ounce  of  sal  ammoniac  ",  four  ounces 
of  grain  tin.  The  tin  is  to  be  divided 
into  eight  portions,  and  one  of  them  is 
to  be  put  into  the  acid  mixture  every 
quarter  of  an  hour. 

A  solution  of  chlorate  of  potassa  (chlo- 
ride ?)  is  said  to  beautify  scarlet  cloth  in 
a  remarkable  manner. 

Bancroft  proposed  to  supplant  the  ni- 
tro-muriatic  acid,  by  a  mixture  of  sul- 
phuric and  muriatic  acids,  for  dissolving 
tin  ;  but  I  do  not  find  that  he  succeeded 
in  persuading  scarlet-dyers  to  adopt  his 
plans.  In  fact,  the  proper  base  may  be, 
perhaps,  a  mixture  of  the  protoxyde  and 
peroxyde  of  tin  ;  and  this  cannot  be  ob- 
tained by  acting  upon  the  metal  with  the 
murio-sulphuric  acid.  He  also  prescribed 
the  extensive  use  of  the  quercitron  yel- 
low to  change  the  natural  crimson  of  the 
cochineal  into  scarlet,  thereby  economiz- 
ing the  quantity  of  this  expensive  dye- 
stuff. 

SCHEELE'S  GEEEN  is  a  pulverulent 
arsenite  of  copper,  which  may  be  pre- 
pared as  follows  : — Form,  first,  an  arse- 
nite of  potassa,  by  adding  gradually  11 
ounces  of  arsenious  acid  to  2  pounds  of 
carbonate  of  potassa,  dissolved  in  10 
pounds  of  boiling  water  ;  next,  dissolve 
2  pounds  of  crystallized  sulphate  of  cop- 
per in  30  pounds  of  water ;  filter  each  so- 
lution, then  pour  the  first  progressively 
into  the  second,  as  long  as  it  produces  a 
rich  grass-green  precipitate.  This  being 
thrown  upon  a  filter-cloth,  and  edulcora- 
ted with  warm  water,  will  afford  1  pound 
6  ounces  of  this  beautiful  pigment.  It 
consists  of,  oxide  of  copper  28*51,  and 
of  arsenious  acid  71-46.  This  green  is 
applied  by  an  analogous  double  decom- 
position of  cloth.     (See  Calico-printing.) 

SCHWEINFUETH  GKEEN  is  a  more 
beautiful  and  velvety  pigment  than  the 
preceding,  which  was  discovered  in  1814, 
and  remained  for  many  years  a  profitable 
secret.  M.  Liebig  having  made  its  com- 
position known,  in  1822,  it  has  been  since 
grepared  in  a  great  many  color-works. 
Iraconnot  published,  about  the  same 
time,  another  process  for  manufacturing 
the  same  pigment.  Its  preparation  is 
very  simple  ;  but  its  formation  is  accom- 
panied with  some  interesting  circum- 
stances.   On  mixing  equal  parte  of  ace- 


554 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


[SCO 


tate  of  copper  and  arsenious  acid,  each 
in  a  boiling  concentrated  solution,  a 
bulky  olive-green  precipitate  is  immedi- 
ately produced  ;  while  much  acetic  acid 
is  set  free.  The  powder  thus  obtained, 
appears  to  be  a  compound  of  arsenious 
acid  and  oxide  of  copper,  in  a  peculiar 
state  ;  since  when  decomposed  by  sul- 
phuric acid,  no  acetic  odor  is  exhaled. 
Its  color  is  not  changed  by  drying,  by 
exposure  to  air,  or  by  being  heated  in 
water.  But,  if  it  be  boiled  in  the  acidu- 
lous liquor  from  which  it  was  precipita- 
ted, it  soon  changes  its  color,  as  well  as 
its  state  of  aggregation,  and  forms  a 
new  deposit  in  the  form  of  a  dense 
granular  beautiful  green  powder.  As 
fine  a  color  is  produced  by  ebullition 
during  five  or  six  minutes,  as  is  obtained 
at  the  end  of  several  hours  by  mixing 
the  two  boiling  solutions,  and  allowing 
the  whole  to  cool  together.  In  the  latter 
case,  the  precipitate,  which  is  slight  and 
flocky  at  first,  becomes  denser  by  de- 
grees ;  it  next  betrays  green  spots,  which 
progressively  increase,  till  the  mass 
grows  altogether  of  a  crystalline  consti- 
tution, and  of  a  still  more  beautiful  tint 
than  if  formed  by  ebullition. 

SCISSEL.  The  clippings  of  various 
metals  produced  in  several  mechanical 
operations  concerned  in  their  manufac- 
ture. The  slips  or  plates  of  metal  out 
of  which  circular  blanks  have  been  cut 
for  the  purpose  of  coinage  are  called 
scisscl  at  the  mint. 

SCOUKING  and  Cleansing.  The 
general  principle  of  cleansing  all  spots, 
consists  hi  applying  to  them  a  sub- 
stance which  snail  have  a  stronger  affini- 
ty for  the  matter  composing  them,  than 
this  has  for  the  cloth,  and"  which  shall 
render  them  soluble  in  some  liquid  men- 
struum, such  as  spirits,  naptha,  oil  of  tur- 
pentine, &c.     (See  Bleaching.) 

Alkalies  would  seem  to  be  proper  in  this 
point  of  view,  as  they  are  the  most  pow- 
erful solvents  of  grease  ;  but  they  act 
too  strongly  upon  silk  and  wool,  as  well 
as  change  too  powerfully  the  colors  of 
dyed-stuffs,  to  be  safely  applicable  in 
removing  stains.  The  substances  for 
this  purpose  are — 1.  Soap.  2.  Chalk, 
fullers  earth,  soap-stone  or  steatite 
(called  in  this  country  French  chalk). 
These  should  be  merely  diffused  through 
a  little  water  into  a  thin  paste,  spread 
upon  the  stain  and  allowed  to  dry.  The 
spot  requires  now  to  be  merely  brushed. 
3.  Ox-gall  and  volk  of  q^  have  the 
property  of  dissolving  fatty  bodies  with- 
out affecting  perceptibly  the  texture  or 


colors  of  cloth,  and  may  therefore  be  cm- 
ployed  with  advantage.  The  ox-gall 
should  be  purified,  to  prevent  its  green- 
ish tint  from  degrading  the  brilliancy  of 
dyed-stuffs,  or  the  purity  of  whites. 
Thus  prepared  (see  Gall),  it  is  the  most 
precious  of  all  substances  known  for  re- 
moving these  kind  of  stains.  4.  The 
volatile  oil  of  turpentine  will  take  out 
only  recent  stains  ;  for  which  purpose  it 
ought  to  be  previoasly  purified  by  dis- 
tillation over  quicklime.  Wax,  resin, 
turpentine,  pitch,  and  all  resinous  bodies 
in  general,  form  stains  of  greater  or  less 
adhesion,  which  may  be  dissolved  out 
by  pure  alcohol.  The  juices  of  fruits, 
and  the  colored  juices  6f  all  vegetables 
in  general,  deposit  upon  clothes  marks 
in  their  peculiar  hues.  Stains  of  wine, 
mulberries,  black  currants,  moreiL  *,  li- 
quors, and  weld,  yield  only  to  soaping 
with  the  hand,  followed  by  fumigation 
with  sulphurous  acid  ;  but  the  latter 
process  is  inadmissible  with  certain  col- 
ored stuffs.  Iron  mould  or  rust  stains 
may  be  taken  out  almost  instantaneously 
with  a  strong  solution  of  oxalic  acid.  If 
the  stain  is  recent,  cream  of  tartar  will 
remove  it. 

Compound  Spots. — That  mixture  of 
rust  of  iron  and  grease  called  cambottis 
by  the  French,  is  an  example  of  this 
kind,  and  requires  two  distinct  opera- 
tions ;  first,  the  removal  of  the  grease, 
and  then  of  the  rust,  by  the  means  above 
indicated. 

Mud,  especially  that  of  cities,  is  a  com- 
pound of  vegetable  remains,  and  of  fer- 
ruginous matter  in  a  state  of  black  ox- 
ide. Washing  with  pure  water,  followed 
if  necessary  with  soaping,  will  take  away 
the  vegetable  juices  ;  arid  then  the  iron 
may  be  removed  with  cream  of  tartar, 
which  itself  must,  however,  be  well 
washed  out.  Ink  stains,  when  recent, 
may  be  taken  out  by  washing,  first  with 
pure  water,  next  with  soapy  water,  and 
lastly  with  lemon  juice  ;  but  if  old,  they 
must  be  treated  with  oxalic  acid.  Stains 
occasioned  by  smoke,  or  by  sauces 
browned  in  a  frying-pan,  may  be  sup- 
posed to  consist  of  a  mixture  of  pitch, 
black  oxide  of  iron,  empyreumatic  oil, 
and  some  saline  matters  dissolved  in 
pyroligneous  acid.  In  this  case  several 
reagents  must  be  employed  to  remove 
the  stains.  Water  and  soap  dissolve  per- 
fectly well  the  vegetable  matters,  the 
salts,  the  pyroligneous  acid,  and  even 
the  empyreumatic  oils  in  a  great  mea- 
sure ;  the  essence  of  turpentiue  will  re- 
move the  rest  of  the  oils  and  all  the 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


555 


pitchy  matter ;  then  oxalic  acid  may  be 
used  to  discharge  the  iron.  Coffee  stains 
require  a  washing  with  water,  with  a 
careful  soaping,  at  the  temperature  of 
120°  F.,  followed  by  snlphuration.  The 
two  latter  processes  may  be  repeated 
twice  or  thrice.  Chocolate  stains  may  be 
removed  by  the  same  means,  and  more 
easily. 

As  to  those  stains  which  change  the 
color  of  the  stuff,  they  must  be  corrected 
by  appropriate  chemical  reagents  or 
dyes.  When  black  or  brown  cloth  is  red- 
dened by  an  acid,  the  stain  is  best  coun- 
teracted' by  the  application  of  water  of 
ammonia.  If  delicate  silk  colors  are  in- 
jured by  soapy  or  alkaline  matters,  the 
stains  must  be  treated  with  colorless 
vinegar  of  moderate  force. 

SCREW.  In  mechanics,  one  of  the 
six  mechanical  powers,  consisting  of  a 
spiral  ridge  or  groove,  winding  round  a 
cylinder,  so  as  to  cut  every  line  on  the 
surface  parallel  to  the  axis  at  the  same 
angle.  The  screw  may  be  formed  either 
on  the  outside  or  inside  of  the  cylinder; 
in  the  former  case,  it  is  called  the  exte- 
rior or  male  screw  :  in  the  latter,  the  in- 
terior or  female  screw.  The  action  of  the 
screw  resembles  that  of  the  wedge,  or 
inclined  plane  ;  but  as  the  cylinder  has 
always  a  handle  attached  to  it,  the  screw 
is  in  reality  a  compound  of  the  inclined 
plane  and  lever  ;  and  if  the  direction  of 
the  power  be  parallel  to  the  base  of  the 
cylinder,  and  perpendicular  to  its  radius, 
an  equilibrium  is  produced  when  the 
power  is  to  the  resistance  or  pressure  as 
the  interval  between  the  adjacent  threads 
is  to  the  circumference  described  by  the 
point  to  which  the  power  is  applied. 
Hence  the  mechanical  advantage  afforded 
by  the  screw  is  proportional  jointly  to 
the  fineness  of  the  threads  andthesmall- 
ness  of  the  cylinder  relatively  to  the 
length  of  the  lever  or  handle.  It  is  to 
be  observed,  however,  that  by  diminish- 
ing the  distance  between  the  threads,  or 
by  diminishing  the  diameter  of  the  cyl- 
inder, we  diminish  also,  in  both  cases, 
the  strength  of  the  screw ;  and  hence 
there  is  obviously  a  limit  to  the  increase 
of  power.  But  the  action  is  greatly  in- 
creased by  means  of  the  contrivance 
called  a  double  screw,  or,  from  the  name 
of  its  inventor,  Hunter's  screw,  which 
consists  in  the  combination  of  two  screws 
of  unequal  fineness  of  thread,  one  of 
which  works  within  the  other.  In  this 
case  the  power  does  not  depend  upon 
the  interval  between  the  threads  of  either 
screw,  but  on  the  difference  between  the 


intervals  in  the  two  screws,  and  may  be 
increased  to  almost  any  extent. 

The  endless  screw  consists  of  a  screw 
combined  with  a  wheel  and  axle  in  such 
a  manner  that  the  threads  of  the  screw 
work  into  the  teeth  fixed  on  the  periphery 
of  the  wheel.  Suppose  the  power  applied 
to  the  handle  of  the  screw,  and  the  weight 
attached  to  the  axle  of  the  wheel,  then 
there  will  be  equilibrium  when  the  power 
is  to  the  weight  as  the  distance  between 
the  threads  multiplied  by  the  radius  of  the 
axle  is  to  the  length  of  the  lever  or  han- 
dle, multiplied  by  the  radius  of  the  wheel. 

The  water  screw,  or  screw  of  Archimedes, 
is  formed  by  winding  a  flexible  tube 
round  a  cylinder  in  the  form  of  a  screw. 
If  the  machine,  thus  constructed,  be 
placed  obliquely,  so  as  to  make  with  the 
vertical  an  angle  equal  to  that  which  the 
spiral  makes  with  the  lines  parallel  to  the 
axis  of  the  cylinder,  there  will  be  in  each 
convolution  of  the  spiral  a  part  parallel  to 
the  horizon.  If  any  body,  then,  be 
placed  within  the  spiral  at  this  part,  it 
■will  remain  at  rest ;  and  if  the  screw  be 
turned  the  body  will  ascend,  because  the 
part  of  the  screw  behind  it  becomes  more 
inclined  than  the  part  before  it,  and  it  is 
consequently  urged  forward.  This  sim- 
ple but  ingenious  contrivance  is  usually 
employed  for  the  purpose  of  raising  wa- 
ter to  a  small  height,  but  it  may  be  em- 
ployed to  raise  any  substance  that  can  pass 
within  the  tube ;  and  it  is  evident  that 
the  action  may  be  increased  by  placing 
several  tubes  or  spiral  channels  (for  they 
may  be  formed  or  wood  or  iron)  on  the 
same  cylinder.  The  principle  has  been 
recently  applied  to  the  propelling  of 
steam- vessels. 

The  micrometer  screio  is  a  contrivance 
adapted  to  astronomical  or  optical  instru- 
ments, for  the  purpose  of  measuring  an- 
gles with  great  exactness.  The  very 
great  space  through  which  the  lever  of 
the  screw  passes  in  comparison  of  that 
which  is  described  by  the  cylinder  in  the 
direction  of  its  length,  renders  the  screw 
of  immense  use  in  subdividing  space  into 
minute  parts. 

As  a  mechanical  power,  the  screw  has 
innumerable  applications  ;  but  is  employ- 
ed with  most  effect  in  all  cases  in  which 
a  very  great  pressure  is  required  to  be 
exertedVithin  a  small  space  and  without 
intermission.  Hence  it  is  the  power  gen- 
erally used  for  expressing  juices  from 
solid  substances,  for  compressing  cotton 
and  other  goods  into  hard  dense  masses 
for  the  convenience  of  carriage,  for  coin- 
ing, stamping,  printing,  &c. 


556 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sea 


SCREW-CUTTING.  Those  who  are 
possessed  ofa  lathe  with  a  slide-rest  to  it, 
which  is  now  in  very  frequent  nse,  may 
cor  vert  the  screw  of  that  rest  into  a  pat- 
ten, screw,  whereby  to  cut  original  right 
and  left  threaded  screws  of  various  rakes 
and  diameters,  in  the  following  simple 
manner  : — The  screw  of  the  slide-rest  has 
generally  a  square  formed  at  one  end  of 
it,  to  fit  a  winch  or  handle  upon,  in  order 
to  turn  the  screw  and  urge  the  turning 
tool  forward.  Now  it  will  be  necessary 
to  have  another  square,  also  formed  at 
the  opposite  end  of  the  screw,  upon  which 
a  square  socket  can  be  secured  by  a  bind- 
ing-screw ;  this  socket  is  united  with 
one  of  the  forks  of  Hook's  universal 
joint,  formed  of  two  such  forks,  with 
screws  passing  through  the  ends  of  the 
forks,  having  conical  points  to  them, 
which  enter  into  four  holes  made  around 
an  iron  ball  or  sphere,  at  equal  distances 
apart ;  the  two  forks  being  thus  affixed 
to  the  ball,  at  right  angles  to  each  other, 
and  as  usual  in  forming  this  kind  of  uni- 
versal joint.  The  stem  of  this  second 
fork  is  elongated,  and  has  a  neck  or  pivot 
made  near  its  other  end,  which  works 
in  a  cleft  pivot-hole,  formed  in  a  standard, 
which  is  affixed  on  the  top  of  a  cylindrical 
stem,  which  can  be  fitted  into  the  socket 
of  the  ordinary  lathe-rest,  and  bound  by 
its  screw  as  usual.  Upon  the  exterior 
end  of  the  stem,  beyond  the  neck  or 
pivot,  toothed  wheels  or  pinions,  as  the 
case  may  require,  must  oe  fitted,  and 
bound  tight  by  a  screw  and  nut ;  and  in- 
to or  upon  the  nose  of  the  lathe-mandrel, 
a  chuck  must  be  screwed,  which  can, 
likewise,  have  other  toothed  wheels  or 
pinions  affixed  upon  it,  next  or  adjoining 
to  the  mandrel,  to  work  into  the  first 
mentioned  toothed  wheels  or  pinions. 
The  front  end  of  the  chuck  must  also 
have  a  square  hole  made  in  it,  to  receive 
into  it  the  squared  end  of  the  steel  cylin- 
der, which  is  to  have  the  screw  cut  upon 
it ;  and  the  other  end  of  which  cylinder 
is  to  be  supported  by  the  back  centre  of 
the  lathe  as  usual. 

A  properly-shaped  turning-tool  is  then 
to  be  placed  and  screwed  fast  in  the  socket 
of  the  slide  of  the  slide-rest,  and  be 
brought  to  act  upon  the  steel  cylinder, 
which  is  to  be  cut  into  the  screw  in  the 
usual  manner  of  turning;  and,  by  the 
disparity  in  the  proportions  of  the  tooth- 
ed wheel-work,  the  turning  tool  will  be 
carried  along  faster  or  slower,  so  either  as 
to  cut  coarser  or  finer  threaded  screws 
than  the  original  one,  or  a  similar  one, 
though  of  a  different  diameter,  if  the 


toothed  wheels  be  equal.  The  universal 
joint  here  is  necessary,  to  accommodate 
the  change  of  motion  from  a  right  line  to 
any  angle  less  than  a  right  angle".  Should 
left  hand  threaded  screws  be  required,  an 
intermediate  wheel  or  pinion,  to  reverse 
the  motion,  must  be  affixed  to  the  stand- 
ard, and  be  brought  to  act  in  the  other 
wheels  or  pinions. 

The  following  is  a  simple  and  econo- 
mical method  of  cutting  original  screws : 
You  must  leave  the  piece  of  steel  from 
which  you  intend  to  form  your  tap  a  lit- 
tle longer  than  necessary,"  and  having 
turned  it  true  throughout,  at  one  end  turn 
down,  somewhat  lower  than  the  rest,  a 
neck  or  space  about  half  an  inch  in 
length ;  round  this  space  coil  a  piece  of 
wire,  and  you  will,  at  once,  be  in  posses- 
sion of  a  primary  artificial  guide,  which 
will  regulate  the  pitch  of  your  intended 
screw.  You  have  nothing  now  to  do 
but  to  make  your  tracing-tool  to  the 
spiral  groove  formed  by  the  wire,  and  be- 
gin tracing  your  thread.  By  this  simple 
method  you  may  obtain,  by  varying  the 
thickness  of  your  wire,  a  screw  of  any  re- 
quired pitch,  either  right  hand  or  left. 

SEALING-WAX.  The  wax  used  for 
sealing  letters,  legal  instruments,  &c. 
The  best  red  sealing-wax  is  made  by 
melting  in  a  very  gentle  heat  48  parts  of 
shell-lac  with  19  of  Venice  turpentine 
and  1  of  Peruvian  balsam  ;  32  parts  of 
the  finest  cinnabar,  thoroughly  levigated, 
are  then  stirred  in,  and  the  "whole  well 
mixed.  When  it  has  cooled  down,  it  is 
either  rolled  into  sticks,  or  shaped  in 
brass  moulds.  The  best  black  sealing- 
wax  is  a  mixture  of  60  parts  of  shell-lac 
and  80  of  ivory  black  ;  it  may  be  perfum- 
ed with  a  little  Peru  balsam  or  sty  rax. 
The  earliest  application  of  sealing-wax  to 
its  present  use  seems  to  have  been  made 
about  the  year  1553.  The  first  printed 
account  of  it  is  said  by  Berzelius  to  have 
appeared  in  1563.  The  great  seals  ap- 
plied in  tin  boxes  to  certain  legal  docu- 
ments are  made  ofa  mixture  of  15  parts 
of  Venice  turpentine,  5  of  olive  oil  and  8 
of  wax  melted  together,  and  colored  with 
red  lead. 

Other  varieties  of  sealing-wax  are  made 
thus: — To  make  red,  take  of  camphor,  4 
oz.  •  Venice  turpentine,  2  lbs. :  vermilion, 
1$  lb.,  rectified  spirit  of  wine,  16  oz. 
Dissolve  the  camphor,  first,  in  the  recti- 
fied spirit  of  wine  in  a  suitable  vessel, 
over  a  slow  fire,  taking  care  that  no  flame 
touches  the  evaporating  spirit :  then  add 
the  shell-lac;  and  when  that  has  become 
of  an  uniform  smoothness  by  a  moderate 


sem] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


557 


application  of  heat,  add  the  Venice  tur- 
pentine, and  lastly,  the  vermilion,  which 
should  be  passed  through  a  hair-sieve 
held  over  the  melted  mass,  in  order  that 
it  may  not  get  into  clots.  When  the 
whole  is  well  incorporated  it  may  be 
formed  into  sticks. 

It  is  usual  to  weigh  out  the  soft  wax 
into  balls,  and  roll  them  on  a  table  into 
the  lengths  desired,  and  then  flatten 
them  by  pressure.  They  are  polished 
by  being  held  over  a  charcoal  fire  in  a 
chafing-dish,  then  drawn  over  a  tallow 
candle  and  rubbed  with  soft  leather. 

Black  wikc.  Instead  of  vermilion,  em- 
ploy lampblack.  Black  resin  is  also  often 
used  in  about  one-third  the  quantity  of 
the  shell-lac,  thus  :  Take  of  camphor,  1 
oz. ;  shell-lac,  2i  lbs. ;  black  resin,  1*  lbs. ; 
oil  of  turpentine  8  oz. ;  rectified  spirit  of 
wine,  8  oz. ;  lampblack,  4  oz.  Dissolve 
the  camphor  in  the  rectified  spirit  of  wine, 
then  add  the  shell-lac,  to  which  pour  the 
resin  previously  melted  and  mixed  with 
the  oil  of  turpentine;  using,  of  course,  a 
moderate  heat,  and  taking  care  that  no 
flame  touches  the  melting  matters. 

SECTOE.  A  mathematical  instrument, 
of  considerable  use  in  making  diagrams, 
laying  down  plans,  &c.  Its  principal  ad- 
vantage consists  in  the  facility  with 
which  it  gives  a  graphical  determination 
of  proportional  quantities ;  and  hence  it 
is  called  by  the  French  the  compass  of  pro- 
portion. 

The  instrument  consists  of  two  rulers 
(generally  of  brass  or  ivory),  represent- 
ing the  radii  of  a  circular  arc,  and  mov- 
able round  a  joint,  the  middle  of  which 
forms  the  centre  of  the  circle.  From  this 
centre  there  are  drawn  on  the  faces  of  the 
rulers  various  scales  ;  the  choice  of  which, 
and  the  order  of  their  arrangement,  may 
be  determined  by  a  consideration  of  the 
uses  for  which  the  instrument  is  chiefly 
intended.  The  scales  usually  put  on  sec- 
tors are  of  two  kinds — single  and  double ; 
that  is  to  say,  such  as  are  drawn  only  on 
one  of  the  limbs,  and  such  as  are  drawn 
on  both  limbs.  The  first  kind,  however, 
(comprising,  for  example,  aline  of  inches, 
of  chords,  sines,  logarithms,  &e.)  are  not 
peculiar  to  the  sector,  but  are  merely 
placed  there  for  convenience,  and  may  be  ! 
used  whether  the  instrument  is  shut  or  ; 
open.  Of  the  lines  repeated  on  both  ! 
limbs,  the  principal  are  the  following  : —  \ 
1.  A  line  of  equal  parts,  by  which,  with 
a  pair  of  compasses,  we  are  enabled,  on  | 
the  principle  that  similar  triangles  have 
their  homologous  sides  proportional,  to 
find  a  third  proportional  to  two  t>iv 


given 


lines,  a  fourth  proportional  to  three  given 
lines,  to  diminish  a  line  in  any  given  pro- 
portion, &c.  2.  A  scale  of  chords,  which 
enables  us  to  protract  an  angle  of  any  giv- 
en number  ot  degrees,  to  find  the  degrees 
which  any  given  angle  contains,  to  cut 
off  an  arc  of  any  given  magnitude  from 
the  circumfeience  of  a  given  circle,  &c. 
S.  Scales  of  sines,  tangents,  and  secants, 
whereby  the  length  of  the  trigonometrical 
lines  corresponding  to  a  given  arc  of  a 
circle  of  any  radius  are  determined.  4. 
A  line  of  polygons,  whereby  the  propor- 
tional length  of  the  side  of  any  regular 
polygon  (of  not  more  than  12  sides)  to 
the  radius  of  the  circumscribing  circle  is 
found. 

The  sector  may  be  used  in  trigonometry 
for  obtaining  a  rough  solution  of  all  the 
cases  of  right-angled  plane  triangles  ;  and 
it  is  also  conveniently  applied  to  the 
construction  of  various  geometrical  pro- 
blems. 

SEGGAR  is  the  fire-clay  cylindrical 
vessel  in  which  earthenware  is  baked. 

SELENIUM,  from  X^A/ji/r?,  the  moon,  is 
a  metalloid  principle,  discovered  by  Ber- 
zelius,  in  1817.  It  occurs  sparingly  in 
combination  with  several  metals,  as  iead, 
cobalt,  copper,  and  quicksilver,  in  the 
Harz,  at  Tilkerode ;  with  copper  and  sil- 
ver (Eukairite)  in  SAveden,  with  tellurium 
and  bismuth  in  Norway,  with  tellurium 
and  gold  in  Siebenburgen,  in  several  cop- 
per and  iron  pyrites,  and  with  sulphur 
in  the  volcanic  products  of  the  Lipan  Isl- 
ands. Selenium  has  been  found  likewise 
in  a  red  sediment  which  forms  upon  the 
bottoms  of  the  lead  chambers  in  which 
oil  of  vitriol  has  been  made  from  peculiar 
pyrites,  or  pyritous  sulphur.  The  ex- 
traction of  selenium  from  that  deposit  is 
a  very  complex  process. 

Selenium,  after  being  fused  and  slow- 
ly cooled,  appears  of  a  bluish-gray  color, 
with  a  glistening  surface  ;  but  it  is  red- 
dish-brown, and  of  metallic  lustre,  when 
quickly  cooled.  It  is  brittle,  not  very 
hard,  and  has  little  tendency  to  assume 
the  crystalline  state.  Selenium  is  dark 
red  in  powder,  and  transparent,  with  a 
ruby  cast,  in  thin  scales.  Its  specific  gra- 
vity is  4'30.  It  softens  at  the  temperature 
of  176°  F.,  is  of  a  pasty  consistence  at 
212°,  becomes  liquid  at  a  somewhat  high- 
er heat,  forming  in  close  vessels  dark 
yellow  vapors,  which  condense  into  black 
drops ;  but  in  the  air  the  fumes  have  a 
cinnabar  red  color. 

SEMOULE.  The  name  given  in 
France,  and  used  in  this  country,  to  de- 
note the  large  hard  grains  of  wheat  flour 


558 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sew 


retained  in  the  bolting  machine  after  the 
fine  flour  has  been  passed  through  its 
meshes.  The  best  semoule  is  obtained 
from  the  wheat  of  the  southern  parts  of 
Europe.  With  the  semoule,  the  fine 
white  Parisian  bread  called  gruau  is 
baked.  Skilful  millers  contrive  to  pro- 
duce a  great  portion  of  semoule  from  the 
large  -grained  wheat  of  Naples  and 
Odessa. 

SEPIA.  In  the  fine  arts,  a  species  of 
pigment  prepared  from  a  black  juice  se- 
creted by  certain  glands  of  the  sepia  or 
cuttlefish,  which  the  animal  ejects  both 
to  darken  the  water  when  it  is  pursued, 
and  as  a  direct  means  of  annoyance. 

All  the  varieties  of  the  sepia  yield  this 
juice ;  but  the  Sepia  officinalis,  which  is 
so  common  in  the  Mediterranean,  is 
chiefly  sought  after,  from  the  profusion 
of  color  which  it  affords.  It  is  insoluble 
in  water,  but  is  extremely  diffusible 
through  it,  and  is  very  slowly  deposited. 
When  prepared  with  caustic  lye,  it  forms 
a  beautiful  brown  color  with  a  flne  grain, 
and  has  given  name  to  a  species  of  draw- 
ing now  extensively  cultivated  for  land- 
scapes and  other  branches  of  the  fine 
arts.  The  honor  of  the  invention  of  the 
sepic  drawing  is  due  to  Professor  Seidel- 
mann,  of  Dresden,  who  discovered  it  at 
Eome  in  1777. 

SEEGE.  A  cloth  of  quilted  woollen, 
extensively  manufactured  in  Devonshire 
and  other  English  counties. 

SEEPENTINE  is  a  mineral  of  the  mag- 
nesian  family,  of  a  green  color;  it  is 
scratched  by  calcareous  spar,  it  is  sectile, 
tough,  and  therefore  easily  cut  into  orna- 
mental forms. 

Its  most  abundant  locality  in  this  coun- 
try is  at  Hoboken,  N.  J.,  and  in  Ver- 
mont. 

SEWEE.  In  architecture,  a  subter- 
raneous conduit,  or  channel,  to  receive 
and  carry  off  the  superfluous  water  and 
filth  of  a  city.  The  sewers  of  Eome  have 
been  the  models  of  those  of  the  modern 
cities  of  Europe.  They  are  as  old  as  the 
elder  Tarquin.  These  chacce had,  between 
the  Quirinal,  Capitoline,  and  Palatine 
hiUs,  many  branches,  which  joining  in 
the  Forum,  now  the  Campo  Vaccino, 
were  received  for  conveyance  into  the 
Tiber  by  a  larger  one  called  the  cloaca 
maxima.  It  must  be  admitted,  however, 
that  it  is  erroneous  to  designate  the  Eo- 
man  cloacae  by  the  term  sewers.  They 
were  rather  drains,  made  to  carry  off  the 
stagnant  water  of  the  pestilential  marshes 
which  occupied  much  of  the  low  ground 
near  the  Tiber,  and  the  spaces  between 


the  Aventine,  Palatine,  and  Capitoline 
hills.  The  height  and  width  of  the  cloaca 
maxima  are  equal,  each  measuring  13i 
feet. 

Sewers.  The  whole  length  of  eewers 
in  the  City  of  New  York,  at  the  close  of 
the  year  1850,  was  125  miles,  and  during 
the  present  year  there  have  been  added, 
including  what  is  now  under  contract, 
about  11  miles,  making  136  miles  in  all, 
to  be  completed  within  the  present  year. 
The  number  now  in  progress  is  54,  at  an 
average  length  of  800  feet ;  the  average 
contract  price  of  which  is  $3  12£  per 
cubic  foot.  In  addition  to  this,  the  con- 
tractors are  uniformly  allowed  $2  per  cu- 
bic yard  for  excavating  rocks.  "Before 
this  uniform  price  was  established,  it  fre- 
quently happened  that  bidders  at  a  high 
nominal  price  obtained  a  contract  in  pre- 
ference to  a  lower  bidder,  on  account  of  a 
different  estimate  of  the  cost  of  blasting, 
or  otherwise  excavating  the  rocks,  in 
which  there  is  a  great  difference,  not  al- 
ways ascertainable  before  the  work  is 
done.  On  the  present  plan  the  contrac- 
tors, with  a  knowledge  of  the  rates  to  be 
allowed,  are  supposed  capable  of  judging 
of  the  proper  rate  for  building  the  sewer, 
and  their  bids  are  always  made  with  re- 
ference to  the  fact. 

In  consequence  of  sewers  not  formerly 
being  properly  built,  many  of  the  old  ones 
have  required  repairs  which,  under  the 
present  system  of  management,  will  rare- 
ly be  necessary.  No  person  is  now  ap- 
pointed to  the  office  of  inspector  who  is 
not  a  practical  mason-,  and  in  the  absence 
of  personal  knowledge  a  certificate  is  re- 
quired that  the  applicant  has  served  a 
regular  apprenticeship  to  that  business. 
The  care  ot  the  department,  in  the  rigid 
enforcement  of  its  rules,  the  exaction  of 
sufficient  bonds,  and  evidence  of  the  act- 
ual fulfilment  of  contracts,  has  produced 
better  work,  and  is  more  fully  performing 
its  appropriate  agency  for  the  city  than 
at  any  time  heretofore. 

Among  other  improvements,  the  form 
of  the  sewer  has  been  changed  from  a 
round  to  an  oblong,  or  rather  an  egg  form, 
having  the  smallest  diameter  at  the  bot- 
tom. This  does  not  alter  the  capacity  of 
the  sewer,  but  causes  greater  velocity  of 
current,  and  helps  the  sewer  to  cleanse  it- 
self. This  it  would  effectually  do  if  the 
department  should  carry  out  the  plan  to 
which  they  have  given  some  considera- 
tion, of  flu siting  the  sewers  by  means  of 
the  waste  pipes  of  the  Croton,  in  which 
case  they  would  accumulate  but  little 
filth.    The  sluices  are  now  so  construct- 


sha] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


559 


cd  that  while  they  readily  receive  the  wa- 
ter as  well  as  the  mud  from  the  surfaces 
and  gutters  at  every  rain,  the  contamina- 
ted air  is  effectually  prevented  from  ris- 
ing. The  accumulation  of  dirt  in  these 
sluices  is,  in  some  localities,  very  great, 
two  hundred  loads  having  been,  in  one 
instance,  taken  from  a  single  block  in 
Canal-street. 

The  depth  of  the  sewers  is  various,  ac- 
cording to  the  grade  of  the  street  or  dis- 
trict requiring  to  be  drained.  At  their 
termination  in  the  rivers,  they  are,  as  a 
general  rule,  between  two  and  three  feet 
below  high  water  mark.  From  this 
point  they  rise  with  the  average  grade 
they  are  intended  to  drain,  till  they  reach 
a  nearly  uniform  rate  of  18s  feet  below 
the  curb  stones.  In  some  instances,  how- 
ever, the  depth  is  17  feet  or  more,  where 
the  grade  of  the  street  is  more  than  of  or- 
dinary height — the  object  being  to  obtain 
in  each  instance  the  requisite  average  of 
elevation.  For  the  necessary  fall  of  wa- 
ter three  inches  in  10  feet  is  regarded 
sufficient — but  a  greater  rate  is  usually 
allowed. 

In  connection  with  the  use  of  Croton 
water,  the  sewers  are  invaluable,  and  the 
full  benefit  of  the  Croton  could  not  be  ob- 
tained without  them.  To  perceive  this, 
it  is  scarcely  necessary  to  refer  to  the  fa- 
cilities afforded  in  bathing-houses,  water- 
closets,  manufactories,  hotels,  and  other 
places,  where  large  quantities  of  water, 
more  or  less  impure,  must  flow  off  through, 
the  sewers,  or  render  the  atmosphere  un- 
wholesome by  being  discharged  upon  the 
surface  of  the  ground. 

So  important  a  matter  is  it  now  regard- 
ed by  builders  and  owners  of  lots,  that 
scarce  a  building  is  now  commenced  with- 
out an  inquiry  first  at  the  Croton  Water  De- 
partment whether  the  street  has  a  sewer, 
and  at  what  depth  a  cellar  may  be  expect- 
ed to  be  drained.  This  is  the  more  im- 
portant, since  by  the  disuse  of  wells,  the 
level  of  water  in  the  city  has  generally 
risen  to  a  higher  line  than  formerly. 

The  cost  of  the  54  sewers  now  under 
contract,  to  be  completed  within  the  pre- 
sent vear,  is  about  135,000  dollars. 

SEWING-MACHINES.  Machines  of 
this  kind,  until  within  a  few  years,  have 
attracted  but  little  attention  ;  but  as  they 
are  coining  into  use,  and  are  found  to  an- 
swer an  excellent  purpose,  the  inventor 
is  ingeniously  exercising  his  skill  to  im- 
prove them.  No  less  than  five  patents 
have  been  granted  this  year  for  sewing- 
machines.  One  of  these  is  a  re-issue  of  a 
patent  granted  some  years  ago,  and  need 


not  be  noticed.  Two  of  the  others  are 
much  alike,  differing  only  in  minor  parti- 
culars. The  cloth  in  each,  with  its  edge 
properly  presented  to  the  needle,  is  se- 
cured to  a  proper  feeding  apparatus. 
The  needle  is  placed  perpendicular  to  the 
cloth,  in  a  frame  sliding  back  and  forth 
for  inserting  and  withdrawing  it ;  the  eye 
is  near  the  point.  On  the  opposite  side 
of  the  cloth  is  a  twisted  hook,  which  slides 
endwise  in  a  direction  nearly  perpendicu- 
lar to  the  needle  ;  as  the  needle  passes 
through,  Che  thread  is  caught  by  the  hook 
and  drawn  sidewise,  forming  a  loop. 
When  the  needle  again  passes  through 
the  cloth,  it  passes  through  this  loop  also, 
and  the  hook  moves  forward,  releasing 
the  old  loop  and  seizing  the  new  thread, 
forms  anew  loop  passing  through  the  old 
one.  This  operation  combined  produces 
what  is  well-known  as  the  tambour  stitch. 
In  another  of  these  machines  the  thread 
is  carried  through  the  cloth  by  a  bent 
needle,  with  the  eye  near  the  point.  The 
shape  of  the  needle  leaves  a  space  between 
it  and  the  thread.  A  shuttle  upon  a  cir- 
cular way  on  the  side  of  the  cloth  opposite 
the  needle,  has  in  it  a  bobbin  of  thread. 
This  shuttle  is  sharp  pointed  and  curved 
to  adapt  it  to  the  way,  and  as  it  moves 
around  it  passes  through  the  opening  be- 
ween  the  needle  and  the  thread,  and  the 
needle  is  then  withdrawn,  leaving  a  loop 
of  its  own  thread  around  the  thread  of 
the  bobbin.  This,  if  continued,  will  pro- 
duce a  seam.  The  shuttle  is  driven  by 
two  arms  from  the  centre  shaft  with  pins  in 
their  ends  taking  into  perforations  one  in 
each  end  of  the  shuttle,  and  whenever 
one  of  these  pins  approaches  the  thread 
of  the  needle,  it  is  raised  out  of  the  way 
and  the  shuttle  is  driven  by  the  other. 

Various  forms  of  these  machines  have 
been  patented,  such  as  Watson's,  Wil- 
son's, Lerow  and  Blodgett's,  &c. 

SHAFT.  In  mines."  A  shaft  or  pit  is 
a  prismatic  or  cylindrical  hollow  space, 
the  axis  of  which  is  either  vertical  or  much 
inclined  to  the  horizon.  The  dimensions 
of  the  pit,  which  is  never  less  than  32 
inches  in  its  narrowest  diameter,  amounts 
sometimes  to  several  yards.  Its  depth 
may  extend  to  1000  'feet,  and  more. 
Whenever  a  shaft  is  opened,  means  must 
be  provided  to  extract  the  rubbish  which 
continually  tends  to  accumulate  at  its 
bottom,  as  well  as  the  waters  which  may 
percolate  down  into  it ;  as  also  to  facilitate 
the  descent  and  ascent  of  the  workmen. 
For  some  time  a  wheel  and  axle  erected 
over  the  mouth  of  the  opening,  which 
serve  to  elevate  one  or  two  buckets  of 


560 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[she 


proper  dimensions,  may  be  sufficient  for 
most  of  these  purposes  ;  but  such  a  ma- 
chine becomes  ere  long  inadequate. 
Horse-whims,  or  powerful  steam-engines 
must  then  be  had  recourse  to  ;  and  effec- 
tual methods  of  support  must  be  employ- 
ed to  prevent  the  sides  of  the  shaft  from 
crumbling  and  falling  down. 

SHAGREEN.  A  species  of  leather, 
supposed  formerly  to  have  been  prepared 
from  the  skin  of  the  slwgree,  a  species  of 
whale.  It  is  prepared  from  horse  or  ass 
skin,  its  granular  appearance  being  given 
by  imbedding  in  it,  while  soft,  the  seeds 
of  a  species  of  chenopodium,  and  after- 
wards shaving  down  the  surface  :  it  is 
dyed  with  the  green  produced  by  the  ac- 
tion of  sal-ammoniac  on  copper  filings. 
It  was  formerly  much  used  for  watch, 
spectacle,  and  instrument  cases,  and  was 
made  chieflv  in  Astracan. 

SHAMMY,  or  SHAMOY.  The  tanned 
or  tawed  skin  of  the  Chamois  goat.  Any 
soft  pliable  leather  now  passes  under  the 
name.     See  Leather. 

SHAWLS,  CASHMERE.  The  secret 
of  the  quality  of  these  shawls  is  not  in  the 
working ;  it  is  in  the  beautiful  wool  from 
the  goats  of  the  Upper  Thibet,  the  equal 
of  which  in  softness  has  never  yet  been 
found.  The  goats  live  in  high  table-lands 
of  Tartary,  where  the  cold  is  intense,  and 
to  protect  them  from  the  piercing  blast 
of  winter  they  have  the  under-hair  or 
"Poshai,"  of  this  deliriously  soft  and 
warm  material.  This  wool  is  brbnght 
down  to  Cashmere  once  every  year  by 
merchants,  and  sold  to  the  shawl-makers. 
After  thorough  cleaning,  it  is  dyed  of 
various  colors ;  the  dyers  possess  the 
vegetable  or  mineral  ingredients  for  all 
the  colors  except  green,  and  this  they 
procure  from  English  green  baize  by  boil- 
ing. The  color  thus  obtained  is  a  most 
beautiful  and  enduring  one,  and  is  very 
much  prized  by  Mohammedans,  being 
their  holy  color,  to  be  worn  only  by  de- 
scendants of  the  Prophet,  or  those  who 
have  made  the  pilgrimage  to  Mecca. 
The  shawl  patterns  are  drawn  upon  paper, 
very  minute,  and  with  the  greatest  pos- 
sible accuracy  ;  fifty  rupees  are  sometimes 
paid  for  the  mere  drawing  of  a  very  elab- 
orate pattern.  The  dealers  in  shawls  are 
the  agents  of  merchants  residing  in  Bom- 
bay, Delhi,  Lahore,  and  having  branch 
establishments  throughout  Asia.  These 
dealers  give  the  order  and  advance  the 
money  to  the  shawl  manufacturer;  lie 
makes  only  to  order  from  the  dealer  or 
middleman,  and  is  entirely  dependent 
upon  him.    The  loom  is  that  of  the  com- 


monest kind,  the  buildings  in  which  the 
men  work  low,  confined,  and  ill-ventila- 
ted. Each  man  (for  no  women  work  at 
the  loom)  sits  with  his  little  bundle  of 
colored  wools  wound  upon  small  spindles, 
and  a  written  paper  before'him,  by  which 
he  is  entirely  guided  as  to  the  number  of 
threads,  &c,  to  take  up.  He  works  dis- 
tinct from  his  neighbor,  on  his  own  loom ; 
and  as  all  shawls  are  made  up  of  small 
pieces,  each  piece  being  about  eight 
inches  long,  by  four  wide,  the  qualities 
of  every  workman  can  easily  be  detected. 
The  most  skilful  earn  about  eight  anas 
(equal  to  25  cents)  per  day  ;  this  sum  is, 
however,  equivalent  to  a  much  larger 
amount,  if  reckoned  at  what  it  will  pro- 
cure. These  small  pieces,  when  finished, 
are  made  over  to  the  agent  or  dealer,  who 
has  them  sewn  together  in  a  coarse  man- 
ner, to  judge  of  the  general  effect — they 
are  afterwards  washed  in  particular  places 
in  a  stream  branching  from  the  river,  and 
the  water  is  said  to  possess  peculiar  pro- 
perties in  softening  the  wool,  and  bring- 
ing out  the  brilliancy  of  the  colors  not 
found  in  any  other  spot.  But  few  people 
visit  Cashmere  for  the  purpose  of  pur- 
chasing shawls  ;  the  agents  despatch  the 
shawls,  after  they  have  been  washed,  to 
the  larger  marts 'in  Asia,  and  from  their 
correspondents  the  local  merchants  pur- 
chase them.  Besides  the  shawl,  there 
are  several  varieties  of  dress  made  from 
the  wool — one  the  Ahlwan,  perfectly 
plain,  of  a  dirty- white  drab,  and  lilac  col- 
ors ;  the  texture  seems  delightfully  soft, 
but  the  large  price  asked  for  a  piece  five 
or  six  yards  in  length,  seemed  far  above 
the  value.  The  shawl  manufacture  above 
described  is  that  of  the  genuine  and  much 
prized  kind;  an  inferior  sort  called  the 
"zozuni,"  or  sewn,  is  that  in  which  there 
is  a  plain  groundwork  of  wool,  the  Ahl- 
wan dyed  of  any  color,  upon  which  the 
shawl  pattern  is  worked  with  the  needle. 
Many  of  these  are  very  beautiful  in  ap- 
pearance, and  of  most  elegant  patterns, 
but  to  the  eye  of  the  connoisseur  they 
are  almost  destitute  of  value.  The  "  fum- 
awali"  is  a  striped  shawl  material,  wove 
in  the  piece,  and  used  for  dressing-gowns, 
ladies'  dresses,  or  for  the  alkaluk  worn 
by  the  nobles"  of  Lucknow  in  the  cold 
weather. 

SHEATHING.  The  covering  laid  on 
the  ship's  bottom  to  defend  it  "from  the 
worms.  Sheets  of  thin  copper  nailed  on 
with  copper  nails  constitutes,  at  present, 
the  sheathing  of  all  the  better  kinds  of 
vessels.  Lead  has  been  used ;  and  laige- 
headed  iron  nails,  called  scupper  nails,  are 


'] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


561 


used  still  for  the  same  purpose  on  the 
bottom  of  old  hulks,  piles,  &c.  Zinc  and 
different  compositions  have  been  pro- 
posed as  substitutes  for  copper ;  and  Sir 
H.  Davy  ingeniously  suggested  the  ap- 
plication of  pieces  of  zinc  or  iron  upon 
different  parts  of  the  copper  surface, 
which  by  the  action  of  the  sea  water  ren- 
der the  latter  metal  electro-negative,  and 
capable,  therefore,  of  resisting  the  oxid- 
izing and  corrosive  agencies  of  the  sub- 
stances held  in  solution.  The  pieces  of 
iron  or  of  zinc  so  applied  have  been  pro- 
perly called  protectors;  but  by  occasion- 
ing 'the  precipitation  of  earthy  matters 
upon  the  copper,  while  they  effectually 
protect  it,  they  render  its  surface  favor- 
able to  the  adhesion  of  weeds,  barnacles, 
&c,  and  sometimes  to  such  an  extent  as 
to  interfere  with  the  passage  of  the  ship 
through  the  water  :  upon  such  grounds, 
Sir  Humphrey's  valuable  suggestion  has 
been  neglected.  When  vessels  are  laid 
up  in  dock  the  protectors  are  in  success- 
ful use.  Sheathing  formerly  was  com- 
posed of  thin  fir  boards. 

SHELL-LAC.    See  LAC. 

SHINGLES.  In  architecture,  small 
slabs  of  wood,  or  quartered  oaken  boards, 
used  instead  of  slates  or  tiles  for  covering 
churches  or  houses.  They  are  sawn  to  a 
certain  scantling,  or  rather  cleft  to  about 
an  inch  thick  at  one  end,  and  shaped  like 
wedges,  four  or  five  inches  broad,  and 
eight  or  nine  inches  long. 

SHIP- BUILDING.  In  merchantmen, 
the  primary  consideration  is,  to  attain 
the  greatest  capacity  to  carry  cargo,  com- 
bined, as  far  as  possible,  with  safe  and 
easy  movements,  and  rapid  sailing.  In 
this  way  American  builders  have  suc- 
ceeded in  uniting  conflicting  desiderata  in 
a  degree  heretofore  deemed  impossible. 
Our  packet  ships  carry  enormously,  while 
their  extreme  speed  has  reduced,  by  half, 
the  passage  to  Europe. 

The  greatest  breadth  must  always  be 
before  the  centre,  and  consequently,  the 
bow  be  more  blunt  than  the  stern.  The 
best  builders  place  this  point  only  one 
third  of  the  length  from  the  stem.  Ex- 
perience proves  that  it  is  essential  to  fa- 
cilitate the  escape  of  the  displaced  water 
along  the  side  of  the  vessel;  for,  when 
once  a  passage  is  opened  for  the  ship,  the 
fluid  tends  to  re-unite  abaft  the  point  of 
greatest  breadth,  where,  instead  of  offer- 
ing resistance,  it  presses  the  ship  forward 
in  its  endeavor  to  recover  its  level  and 
fill  the  vacuum  constantly  opening  be- 
hind her.  A  log  tows  infinitely  easier  by 
its  bigger  end  ;  and  we  find  a  concurrent 
24* 


testimony  in  the  forms  of  the  finny  tribes 
which  divide  the  element  they  move  in, 
by  a  shape  gradually  diminishing  from 
head  to  tail.  There'is  a  further  advan- 
tage in  having  the  bow  full  towards  the 
edge,  that  it  may  check  descending  into 
the  waves,  not  abruptly,  but  gently : 
pitching  being  the  most  dangerous  to  hull 
and  spars  of  all  movements.  Sharpness 
towards  the  sternpost  is  vitally  essential 
to  fast  sailing.  Stability  increases  as  the 
cubes  of  the  breadth  ;  hence,  by  adding 
one  quarter  to  the  breadth,  you  gain  a 
double  stability,  and,  by  consequence,  a 
capacity  to  bear  twice  as  much  sail,  with 
but  one  fourth  of  increase  in  the  resist- 
ance. The  pressure  of  the  water  increases 
in  descending  from  the  surface,  and,  from 
this  cause  and  the  augmented  difficulty 
of  displacing  it,  the  resistance  offered  to 
a  ship,  in  advancing,  is  three  times  as 
great  at  the  lower  as  at  the  upper  half  of 
the  immersed  section.  An  extreme  in 
breadth,  as  in  length  or  depth,  is  also  dan- 
gerous, and  both  extremes  are  to  be 
equally  avoided. 

The  builder  forms  a  half  model  of  his 
proposed  ship,  making  it  a  quarter  of  an 
inch  to  the  foot.  Moulds  are  then  form- 
ed of  all  the  different  parts.  In  these 
United  States,  where  there  are  abundant 
supplies,  builders  confine  themselves  to 
live  oak,  pine,  chestnut,  locust,  and  cedar. 
The  tree  should  be  taken  in  the  second  era 
of  its  growth,  when  it  has  attained  matu- 
rity, without  approaching  the  period  of 
decay.  It  should  be  killed,  by  removing 
a  ring  of  bark,  at  the  beginning  of  winter, 
when  the  sap  is  down,  and  left  to  dry  and 
harden  before  it  be  cut  down. 

In  laying  down  the  keel,  great  care 
must  be  taken  to  preserve  its  perpendic- 
ularity, for  which  purpose  it  is  pinned 
with  treenails  on  either  side  of  the  blocks : 
also  in  raising  and  propping  the  stem  and 
stern,  and  every  piece  of  the  frame.  As 
the  floor  timbers  are  the  great  connecting 
principles  of  the  ship,  to  which  they  bear 
the  same  relation  as  the  ribs  to  the  body, 
too  much  care  cannot  be  taken  in  selecting 
and  securing  them.  Sometimes  the  frame 
is  made  completely  solid  and  calked  ;  and, 
in  this  case,  the  interior  covering  of  plank 
is  dispensed  with,  excepting  a  few 
strengthening  streaks. 

The  planking  does  not  merely  serve  to 
exclude  the  water,  but  to  protect,  connect, 
and  bind  harmoniously  together,  and  ia 
quite  as  essential  as  the  skin  to  the  body. 
It  is  one  of  the  nicest  arts  of  the  builder 
so  to  carry  up  his  planking,  as  with  little 
waste,  to  keep  his  seams  always  fair  with 


562 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SHI 


the  water-lines.     When  it  is  necessary  to 
bend  a  plank  at  the  bow  or  stern,  it  is 
heated  by  steam,  and  then  forced  into 
place  with  screws  and  levers.     All  being 
complete,  the  carpenter  makes  room  for 
the  calker,  who  carefully  stops  all  the 
seams  with  oakum,  and  smears  them  with 
pitch.    The  scraper  follows  the  calker. 
Sheathing  with  wood  is  practised  with 
iron-fastened  ships,  because  copper  causes 
the  bolt-heads  to  corrode,  if  placed  against 
them.     It  consists  in  covering  the  bottom 
with  pine  boards,  sheets  of  paper  soak- 
ed in   hot  pitch  being  placed  between. 
Two  varieties  of  sails  are  principally  in 
use — the  square  rig,  and  the  fore-and-aft 
Bail.     In  the  square  rig,  square  sails  are 
attached  to  yards,  whose  primitive  posi- 
tion is  at  right  angles  to  the  masts  and 
to  the  plane  of  the  keel ;  but  which  are 
free  to  move  round  the  mast.    In  the 
fore-and-aft  rig,  the  primitive  position  of 
the  sail  is  in  the  plane  of  the  Keel ;  and 
the  sail  is  extended  at  the  top  and  bot- 
tom, by  spars,  known  respectively  as  the 
gaft  and  boom :  these  are  attached  by 
crotches  to  the  mast  and  are  free  to  slide 
up  and  down  it.     Common  to  both  of 
these  rigs  are   the  head  sails  or  jibs — 
which  are  triangular  in  shape  and  extend- 
ed from  the  bowsprit  to  the  foremast  head. 
In  the  naval  service,  the  first  rate  is  a 
ship  of  the  line  of  one  hundred  guns  or 
upwards,  having  three  decks  or  tiers  of 
guns  ;  and  the  seventy-four  is  of  the  line 
but  third  rate,  with  two  decks  or  tiers  of 
guns.    The  titles  of  sloops,  brigs,  corvettes, 
and  cutters,   are  applied  to  the   smaller 
sizes  of  vessels.    In  the  merchant  ser- 
vice, a  ship  has  three  masts,  all  square 
rigged;  a  bark  has  also  three  masts,  but 
carries  square  sails  on  the  fore  and  main- 
masts, and  a  fore-and-aft  sail  on  the  mi- 
zen-mast.     A  brig  has  two  masts,  and  is 
square  rigged.  A  brigantine  or  herinaphro- 
rite  brig  has  two  masts,  and  is  square 
rigged  on  the  fore,  and  fore-and-aft  rig- 
ged on  the  main-mast.     A  schooner  has 
two  masts,  both  rigged  with  fore-and-aft 
sails ;  sometimes  a  topsail  is  added,  and 
the  title  is  changed  accordingly  to  topsail 
schooner.     A  sloop  has  only  one  mast,  and 
is  fore-and-aft  rigged. 

If  we  compare  the  carcase  of  a  ship  to 
the  skeleton  of  the  human  body,  the  keel 
may  be  considered  as  the  back  -bone,  and 
the  timbers  as  the  ribs.  It,  therefore, 
supports  and  unites  the  whole  fabric, 
since  the  stem  and  stern-post,  which  are 
elevated  on  its  ends,  are,  in  some  mea- 
sure, a  continuation  of  the  keel,  and  serve 
to  connect  and  inclose  the  extremities  of 


the  sides  by  transoms ;  as  the  keel  forms 
and  unites  the  bottom  by  timbers.  The 
keel  is  generally  composed  of  several  thick 
pieces,  placed  lengthways,  which,  after 
being  scarfed  together,  are  bolted  and 
clinched  upon  the  upper  side.  When 
these  pieces  cannot  be  procured  long 
enough  to  afford  a  sufficient  depth  to  the 
keel,  there  is  a  strong  thick  piece  of  tim- 
ber bolted  to  the  bottom,  called  the  false 
keel. 

A  new  era  has  taken  place  in  the  art  of 
ship-building;  and  we  are  indebted  to 
Sir  Kobert  Seppings  for  some  of  the  most 
important  improvements  in  marine  archi- 
tecture which  have  characterized  the  pre- 
sent century.  Several  large  ships  have 
already  been  rebuilt  at  Chatham  on  his 
principle,  and  orders  have  been  given  for 
building  several  new  ships. 

1st.  The  frame  of  a  74  gun  ship,  used 
to  be  formed  of  more  than  800  different 
timbers,  placed  at  right  angles  to  the 
keel,  which  may  be  considered  as  the 
back-bone  of  an  animal,  and  the  frame- 
timbers  its  ribs.  Each  rib  is  composed 
of  separate  pieces,  of  the  thickness  of  14 
inches,  or  thereabouts.  Between  the  se- 
veral divisions  of  the  frame  or  ribs,  is  a 
space  from  1  to  5  inches  wide. 

2dly.  The  whole  exterior  frame  was 
covered  with  planks  of  different  thick- 
nesses, or,  to  carry  on  the  figure,  the 
ribs  are  covered  by  a  skin  of  greater  or 
less  substance,  from  the  extreme  ends  of 
them  to  the  keel  or  back-bone.  The  in- 
side of  the  frame  was  also  almost  entirely 
lined  with  planks ;  within  which  is  an- 
other partial  range,  as  it  were,  of  interior 
ribs,  at  a  considerable  distance  from  each 
other,  termed  riders. 

3dly.  Across  this  frame  were  pieces  of 
timber  called  beams,  united  together  so 
as  to  be  of  sufficient  length  to  reach  from 
one  side  of  the  ship  to  the  other. 

From  this  account,  it  will  be  perceived 
that  all  the  materials  composing  the  fab- 
ric of  a  ship,  are  disposed  nearly  at  right 
angles  to  each  other.  And  this  disposi- 
tion, which  is  well  known  to  be  the  weak- 
est, is  particularly  so  in  a  ship,  the  im- 
mense body  of  which,  subject  to  violent 
action  from  impulses  in  every  direction, 
is  sustained  by  a  greater  pressure  on  the 
centre  than  the  extremities,  arising  chief- 
ly from  the  difference  in  the  fore  and  af- 
ter parts  of  the  body,  to  that  of  the  mid- 
ship or  middle  part." 

The  length  of  a  74  gun  ship  being  170 
feet  or  more,  it  requires  but  little  know- 
ledge of  the  strength  of  timber  to  per- 
ceive that  planking  of  that  length,  how- 


'] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


563 


ever  thick,  or  in  whatever  way  joined  or 
put  together,  must,  under  the  present 
system,  bend  with  its  own  weight.  The 
fastenings,  and,  consequently,  the  con- 
nection of  the  several  parts  of  the  fabric, 
must  therefore  suffer  from  the  want  of 
stiffness,  and  a  change  of  form  is  the  con- 
se'quence. 

This  may  be  shown  by  putting  together 
four  pieces  of  wood,  and  then  securing 
them  with  iron  pins  in  the  form  of  a 
square ;  which,  on  the  least  pressure, 
may  be  made  to  change  its  form  to  the 
rhombus  ;  but  let  another  piece  be  fixed 
to  it  diagonally,  and  the  figure  of  the 
frame  will  be  found  immovable.  Place  a 
bar  in  the  middle,  parallel  to  two  of  the 
sides,  and  secure  it  firmly  by  iron  pins ; 
still  the  figure  will  easily  be  moved  by  the 
hand,  like  a  parallel  ruler,  and  assume  the 
rhomboidal  shape ;  but  apply  to  the  frame 
what  the  carpenters  term  the  brace,  as  in 
a  common  field-gate,  and  the  figure  will 
remain  immovable.  And  if  this  brace  or 
diagonal  piece  is  not  fixed  to  it,  the  outer 
part  of  the  gate  (or  that  part  most  dis- 
tant from  the  hinges)  will  have  a  constant 
tendency  downwards,  until  at  length  it 
will  reach  the  ground. 

The  substitution  of  the  triangle,  or 
brace,  for  the  rectangle,  comprehends 
the  principle  of  the  new  system. 

The  arrangement  of  the  materials  in 
the  triangular  mode  is  such,  that  the 
pieces  disposed  horizontally  are  acted 
upon  as  ropes  by  a  strain  of  the  fibre, 
whilst  the  other  parts,  composing  a  series 
of  triangles,  are  pressed  upon  as  pillars  ; 
in  other  words,  the  pressure  acts  in  the 
direction  of  the  fibres  of  the  wood ; 
whereas,  upon  the  rectangular  or  old 
plan,  the  fibres  are  acted  upon  transverse- 
ly, or  across  the  grain,  in  the  same  man- 
ner as  a  stick  is  wheu  placed  across  the 
knee,  and  pressed  by  the  hands  at  each 
end,  which  first  bends,  and  then  breaks. 

To  prevent  any  transverse  action  upon 
the  fibre  of  the  timber  is  one  of  the  ben- 
efits arising  from  the  new  system,  and  to 
impede  a  longitudinal  extension  of  the 
structure,  is  another.  In  a  word,  the  sys- 
tem of  triangles  is  so  constructed,  in  con- 
junction with  the  planking  of  the  ship,  as 
conjointly  to  possess  that  property  of  a 
triangle  already  explained,  viz.,  that  its 
figure  is  as  unalterable  as  the  compression 
or  extension  of  the  fibre  of  timber  will  ad- 
mit it  to  be. 

There  is  considerable  difference  in  the 
details  of  ship-building  as  carried  out  in 
the  United  States  compared  with  that  of 
England.    Even  the  technical  terms  of 


the  art  differ  in  the  two  countries.  Few 
vessels  here  are  built  from  the  draught. 
In  Europe,  the  line  of  flotation,  or  the  in- 
scribed line  at  the  surface  of  the  water, 
is  called  the  first  water  line,  or  load  line, 
and  as  they  descend  the  figures  increase. 
In  this  country,  the  lowest  water  line  is 
denominated  the  first,  and  the  numbers 
increase  as  we  ascend. 

Mr.  Pook,  naval  constructor  at  Charles- 
town,  Mass.',  has  discovered  an  ingenious 
mode  of  determining  the  capacity  of  ves- 
sels, which  is  of  ready  application,  and  is 
adapted  to  all  descriptions  of  freighting 
vessels ;  sharp  vessels,  and  our  ocean 
steamers  are  exceptions,  however,  to  its 
application.  The  rule  is;  from  90°  de- 
duct the  angle  of  the  floor,  or  the  degrees 
of  dead  rise  ;  multiply  by  -0075,  the  quo- 
tient is  the  decimal  for  capacity.  Multiply 
the  length  by  the  breadth,  and  that  pro- 
duct by  the  depth,  from  the  bottom  of  the 
garboard  to  the  load  line,  and  the  last  pro- 
duct by  the  decimal  of  capacity,  and  divide 
by  35,  the  quotient  is  the  capacity  in  tons. 
'The  navigation  laws  of  this  country 
•have  a  very  injurious  effect  upon  ship- 
building, by  budding  for  tonnage  rather 
than  for  quick  sailing.  A  short  time  since 
it  was  thought  necessary  for  a  ship  to  draw 
more  water  aft  than  forward,  in  order  to 
obey  the  helm  readily,  and  this  was  made 
to  appear  on  the  water  lines  by  the  latter 
dipping  considerably  lower  than  the  for- 
mer. This  practice  has  grown  obselete, 
and  parallel  water  lines  are  used.  Mr. 
Griffiths,  in  his  work  on  Marine  and 
Naval  Architecture,  remarks,  that  the  idea 
would  have  been  regarded  as  preposterous 
of  building  a  ship  deeper  forward!  than  aft, 
but  such  is  the  present  practice  of  New 
York,  where  it  was  first  introduced,  and 
the  results  have  proved  most  satifactory, 
ships  having  been  built  in  this  city  hav- 
ing from  3  to  5  feet  of  difference  in  depth 
at  their  ends,  which  adds  greatly  to  their 
appearance  as  well  as  their  performance. 
Stability  of  vessels  in  water  is  desirable, 
but  to  "what  this  property  is  due  is  not 
yet  decided.  It  is  in  part  due  to  the 
breadth  of  the  vessel  compared  with  her 
general  dimensions.  Thus,  increasing 
the  beam,  or  a  less  proportion  of  depth, 
increases  the  stability.  The  steamer 
Georgia  is  the  widest  vessel  of  her  class, 
except  the  Great  Britain,  but  yet  is  one 
of  the  easiest  vessels  in  her  motions  that 
floats.  She  is  3  feet  wider  than  the  Ohio, 
and  wider  than  any  ofthe  Collins  line, 
which  are  much  larger  than  the  Georgia. 
The  Cunard  steamers  are  narrower, 
though  longer  and  deeper.    The  America 


564 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SHI 


and  Europa  Lave  "but  38  feet  of  moulded 
beam,  and  the  Canada  but  391  feet,  while 
the  Georgia,  with  ten  more  feet  of  beam, 
has  more  practical  stability  than  any 
European  steamer.  What  is  true  of 
steamers  is  true  of  ships.  They  may  be 
built  so  long  and  so  wide  that  the  motion 
of  the  sea  will  not  be  felt,  that  is,  they 
will  neither  roll  nor  pitch. 

An  easy  or  light  draught  of  water  is 
essential  to  speed,  and  therefore  to  rive 
navigation;  it  is  generally  looked  for  in 
shape,  whereas  it  probably  should  be 
sought  in  the  nature  of  the  material  and 
in  the  density ;  very  light  draught  iron 
boats  are  superior  to  wood.  Other  cir- 
cumstances concur  to  favor  the  use  of 
iron,  such  as  the  rapid  rotting  of  the  tim- 
ber of  the  West  Indies,  South  America, 
and  even  of  that  of  our  Southern  States  ; 
hence,  for  low  latitudes,  where  ventila- 
tion is  not  perfectly  effected,  iron  ships 
are  more  durable.  The  cost  of  iron  is, 
however,  25  per  cent,  more  than  that  of 
wood.  But  the  saving  afterwards  effect- 
ed is  an  ample  compensation.  The  wa- 
ter tight  bulk-heads  would  be  a  valuable 
adjunct  in  Mississippi  vessels.  These 
prevent  the  boat  from  sinking,  even 
though  a  part  be  snagged  and  full  of  wa- 
ter. The  "  Keindeer,"  on  the  Hudson 
Kiver,  is  a  model  of  speed  even  among 
the  fast  sailing  vessels  of  that  river. 
(See  Steam  Navigation.)  She  was  built 
by  Mr.  T.  Collyer,  in  1850.  She  is  not 
the  largest,  but  is  the  fastest  wooden 
steamer  in  the  Northern  States.  Her  di- 
mensions are,  length,  260  feet ;  breadth, 
34-08  feet;  depth  amidships  from  bare 
line  to  deck  line,  round  of  beam  deduct- 
ed, 9-75  feet;  area  of  her  immersed  mid- 
ship section,  119  square  feet.  Diameter 
of  the  cylinder,  56  inches  ;  stroke  of  pis- 
ton, 12  feet ;  diameter  of  the  water  wheel, 
34  feet ;  face  of  wheel,  9  feet  6  inches ; 
width  of  the  bucket,  24  inches;  calculat- 
ed dip,  9  inches.  Vertical  beam  engine. 
Balance  valves  with  Stevens'  cut  off. 
The  weight  of  the  boiler  is  87,487  lbs. 
Weight  of  the  boat  at  4  feet  draft  of 
water,  147  tons  417  lbs. 

In  river  steamers  there  should  be  a  due 
relation  between  the  proportion  of  the 
boiler  and  the  wheels.  When  the  latter 
turns  fast  enough  to  reduce  the  pressure 
in  the  boiler,  there  is  either  more  wheel 
or  more  boiler  required.  Mr.  Stevens 
proposes  to  increase  the  speed  of  steam- 
boats, by  interposing  a  stratum  of  air  be- 
tween the  flat  surface  of  the  bottom  and 
the  water.  Mr.  S.  has  effected  little  with 
this  himself,   although   he   has   built    a 


vessel  little  inferior  in  speed  to  any 
wooden  boat  of  equal  length  on  the  Hud- 
son, viz.,  an  iron  boat  of  280  feet  long, 
and-  unusual  shape. 

Ocean  steam-ships  for  speed  require 
to  have  their  bows  made  very  sharp,  so 
that  even  at  the  highest  speed  even  the 
smallest  resistance  be  not  generated.  A 
full  bow  generates  resistance,  and  to  drive 
that  form  of  bow  on  with  increased  force,  is 
only  increasing  the  resistance  and  the  dif- 
ficulty. When  it  is  very  sharp,  however, 
she  has  no  buoyancy,  and  becomes  very 
wet,  or  liable  to  ship  seas.  If  speed  be 
required  in  ocean  steam-ships,  they  must 
have  length.  The  steam-ship  Georgia, 
already  alluded  to,  is  the  quickest  sailing 
steamer  in  the  United  States.  She  has 
the  small  end  ahead,  and  has  run  1000 
miles  within  60  consecutive  hours,  or 
equal  to  400  miles  per  day.  Her  mean 
load  line  of  draught  is  16  feet,  beimg  all 
that  is  available  in  running  to  New  Or- 
leans. 

The  coasting  vessels  of  the  United 
States  combine  great  variety  of  shape 
and  dimensions.  There  are  vessels  built 
of  considerable  size  which  run  on  a 
draught  of  3  feet,  and  from  that  up 
to  10  feet,  and  are  on  account  of  their 
breadth  the  most  stable  vessels  in  the 
world.  Some  have  a  centre-board  or 
movable  keel ;  some  have  a  deep  keel : 
some  have  no  centre-board,  and  a  small 
keel.  There  are  a  large  class  of  vessels 
built  in  New  England  principally  for,  and 
engaged  in.  the  lumber  trade,  which  not 
unfrequently  carry  from  one-half  to  five- 
eighths  of  their  cargo  on  deck.  Almost 
all  the  yellow  pine  timber  brought  from 
the  south  comes  in  these, vessels.  The 
timber  which  is  in  the  Jog,  and  very 
long  (55  to  75  feet),  is  carried  on  deck, 
while  the  shorter  lengths  are  taken  in  the 
hold,  through  a  lumber  port  cut  in  the  bow 
immediately  below  the  deck.  Their  great 
fault  is  lowness  of  the  bow,  rendering 
them  so  liable  to  ship  seas  and  get  wreck- 
ed. 

The  famous  Baltimore  clippers  are  now 
being  superseded,  as  being  too  small— 
the  increased  speed  not  making  up  the 
difference  in  dimensions.  They  are  also 
too  deep  for  the  coasting  trade  of  this 
country.  Clipper  ships  of  large  size,  with 
comparatively  less  draft  of  water,  are  now 
being  built  to  a  great  extent  along  the 
eastern  coasts,  especially  in  this  city  (N. 
Y.)  and  in  Maine.  The  pilot  boats  are 
not  only  the  best,  but  the  fastest  vessels 
on  our  coast.  These  are  vertically  sharj 
in  their  bows,  and  thus  part  the  water 


SHO] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


565 


while  vessels  with  round  bows  ride  over 
it.  One  of  these,  the  Mary  Taylor,  built 
by  Mr.  S.  Steers,  of  New  York,  is  looked 
upon  as  the  model  craft  of  this  kind  of 
vessel,  and  has  far  surpassed  the  expecta- 
tion of  her  owners. 

The  river  sloops,  rigged  like  English 
cutters,  are  also  very  fast  sailing  vessels, 
and  carry  on  much  of  the  inland  com- 
merce of  this  country.  They  are  chiefly 
employed  on  the  Hudson  and  East  Kivers, 
(N.  Y.)  in  carrying  freight.  Their  great 
breadth  enables  them  to  carry  enormous 
deck  loads.  The  round  of  the  deck 
transversely  exceeds  that  of  any  other 
kind  of  vessel,  being  often  more  than  12 
inches  in  26  feet. 

During  the  present  year  (1851)  a  tri- 
umph of  American  over  English  ship- 
building has  been  achieved,  in  the  case 
of  the  yacht,  the  schooner  America,  built 
and  owned  by  Mr.  Stevens,  of  New-York, 
which  sailed* for  and  obtained  the  prize 
(value  £100)  of  the  Royal  Yacht  Club  of 
England  at  the  regatta  which  came  off  at 
Cowes  on  22d  August,  1851.  The  yacht 
came  in  52  minutes  ahead  of  the  foremost 
English  vessel.  She  has  since  been  sold 
for  $25,000,  being  about  $5,000  more  than 
it  cost  in  New-York.  She  has  a  clipper 
build,  with  alow,  black  hull,  and  two  masts 
of  extreme  rake  without  extra  rope.  Her 
bow  is  very  sharp,  and  scooped  away 
outward,  swelling  toward  the  stern.  The 
sides  gradually  spring  outward  till  a  little 
forward  of  the  mainmast,  where  she  has 
her  greatest  beam,  being  22  feet  8  inches 
there.  The  stern  is  broad,  wide,  and  full, 
affording  great  accommodation  above 
deck  and  below.  The  bulwarks  are  not 
higher  than  10  inches.  Standing  at  the 
stern  and  looking  forward,  the  deck  is 
nearly  of  a  wedge  shape,  or  like  the  sec- 
tion of  a  carrot,  the  bow  being  as  sharp 
as  the  apex  of  a  triangle,  and  the  stern  be- 
ing little  less  than  the  extreme  breadth  of 
the  beam.    She  is  of  171  tons  burthen. 

In  the  year  ending  June,  1850,  the 
merchant  ships  which  left  port  in  the 
United  States  amounted  to  18,195,  of 
which  8,379  were  American,  and  9,816 
foreign.  The  tonnage  of  these  vessels 
was  4,361,202  tons.  From  New-York 
alone  the  number  of  ships  cleared  was  not 
less  than  2,818  of  1,106,070  tons.  In  1850 
there  were  built  and  launched  from  New- 
York  28  steamships  and  30  sailing  ves- 
sels. 

The  following  statement  shows  the 
number  and  tonnage  of  the  vessels  built 
in  each  state  and  territory  of  the  United 
States,  for  the  year  ending  on  the  30lh  of 


June,  1850.  It  is  taken  from  the  Eeport 
of  the  Secretary  of  the  Treasury,  trans- 
mitting the  annual  report  of  the  Register 
of  the  Treasury  of  the  commerce  and 
navigation  of  the  United  States  for  the 
fiscal  year. 

Of  the  vessels  comprised  in  the  table, 
there  were  two  hundred  and  forty-seven 
ships,  one  hundred  and  seventeen  brigs, 
five  hundred  and  forty-seven  schooners, 
two  hundred  and  ninety  sloops  and  canal 
boats,  and  one  hundred  and  fifty-nine 
steamers.  The  largest  number  of  ships 
built  in  any  state  was  one  hundred  and 
twenty-seven,  in  Maine ;  and  the  largest 
number  of  steamers,  thirty-four,  in  Ken- 
tucky. The  largest  tonnage  set  afloat 
during  the  year  is  that  of  Maine,  and  the 
next  largest  of  New-York.  Of  the  one 
hundred  and  fifty  vessels  built  in  Mary- 
land, one  hundred  and  twenty-five  were 
schooners. 


States. 

Vessels  Built. 

Total  Tonnage. 

326 

10 

I 

121 

14 

47 

224 

57 

185 

16 

150 

8 

34 

33 

5 

2 

3 

24 

34 

5 

13 

31 

14 

1 

2 

91,211  73 

New  Hampshire 

6,914  32 
77  41 

Massachusetts 

Rhode  Island 

Connecticut 

35,836  14 
3,587  15 
4,819  79 

58,342  73 
6,201  68 

21,409  93 
1,848  82 

15,064  80 

288  17 

3,584  04 

2,651  59 

683  82 

New-Jersey 

Pennsylvania  

District  of  Columbia . 

North  Carolina 

Florida 

79  75 

113  66 

1,592  38 
C.460  69 

1,353  82 
1,691  21 
5,214  62 

Ohio 

2,061  63 
105  54 

Texas 

122  42 

Total 

1,360 

272,218  54 

.  SHOT.  Under  the  article  Lead-Shot 
has  been  given  the  usual  process  for 
manufacturing  this  substance. 

It  is  well  known  that  for  a  number  of 
years  past,  all  our  shot  for  fowling-pieces 
lias  been  manufactured  by  dropping  the 
molten  lead  a  great  distance.  For  this 
purpose  tall  towers  were  erected.  An 
invention  has  been  patented  both  at  home 
and  abroad,  by  Mr.  David  Smith,  of  this 
city,  designed  to  make  the  shot  in  any 


566 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SIL 


building,  to  obviate  the  necessity  of  using 
tall  towers ;  the  principle  of  the  invention 
is  highly  ingenious,  and  consists  in  driv- 
ing a  current  of  air  in  a  contrary  direc- 
tion to  the  falling  lead,  which  combined 
with  the  velocity  of  the  falling  lead  from 
a  low  height  (about  50  feet)  will  cool  the 
metal  as  well  as  if  it  fell  from  a  great 
height ;  the  velocity,  according  to  the 
size  of  shot  desired",  being  the  cause  of 
this. 

SHUTTLE.  An  instrument  used  by 
weavers,  which  guides  the  thread  it  con- 
tains, so  as  to  make  it  form  the  woofs  of 
stuffs,  cloths,  linen,  and  other  fabrics,  by 
throwing  the  shuttle  alternately  from  left 
to  right  and  from  right  to  left  across  be- 
tween the  threads  of  the  warp,  which  are 
stretched  out  lengthwise  on  the  loom. 
In  the  middle  of  the  shuttle  is  a  kind  of 
cavity,  called  its  eye  or  chamber,  in  which 
is  enclosed  the  spool,  which  is  part  of  the 
thread  destined  for  the  woof. 

SIENITE  is  a  granular  aggregated 
compound  rock,  consisting  of  feldspar 
and  hornblende,  sometimes  mixed  with  a 
little  quartz  and  mica.  The  hornblende 
is  the  characteristic  ingredient,  and 
serves  to  distinguish  sienite  from  granite, 
with  which  it  has  been  sometimes  con- 
founded ;  though  the  feldspar,  which  is 
generally  red,  is  the  more  abundant  con- 
stituent. The  Egyptian  sienite,  contain- 
ing but  little  hornblende,  with  a  good 
deal  of  quartz  and  mica,  approaches  most 
nearly  to  granite.  It  is  equally  metallife- 
rous with  porphyry ;  in  the  island  of 
Cyprus,  it  is  rich  in  copper ;  and  in 
Hungary,  it  contains  many  valuable  gold 
and  silver  mines. 

Sienite  forms  a  considerable  part  of  the 
centre  of  Staten  Island.  It  takes  its 
name  from  the  city  of  Syene,  in  the  The- 
baid,  near  the  cataracts  of  the  Nile,  where 
this  rock  abounds.  It  is  an  excellent 
building-stone,  and  was  imported  in  large 
quantities  from  Egypt  by  the  Romans, 
for  the  architectural  and  statuary  decora- 
tions of  their  capital. 

SILICA  and  SILICON.  Silica  was  till 
lately  ranked  among  the  earths  proper ; 
but  since  the  researches  of  Davy  and 
Berzelius,  it  has  been  transferred  to  the 
chemical  class  of  acids.  It  constitutes 
the  principal  portion  of  most  of  the  hard 
stones  and  minerals  which  compose  the 
crust  of  the  globe ;  occurring  nearly  pure 
in  rock  crystal,  quartz,  agate,  chalcedony, 
flint,  &c.  Silica  or  silicic  acid  may  be 
obtained  perfectly  pure,  and  also  in  the 
finest  state  of  comminution,  by  taking 
the  precipitate  formed  by  passing  silicat- 


ed  fluoric  gas  through  water,  filtering, 
washing,  and  igniting  it,  to  expel  the  last 
traces   of  the  fluoride   of   silicon.     The 

Eowder  thus  obtained  is  so  light  as  to  be 
lown  away  with  the  least  breath  of  air. 
Silica  may  be  more  conveniently  procur- 
ed, however,  by  fusing  ground  flint  with 
four  times  its  weight  of  a  mixture,  in 
equal  parts,  of  dry  carbonate  of  potassa 
and  carbonate  of  soda,  in  a  platinum  or 
silver  crucible.  The  alkaline  carbonates 
should  be  first  fused,  and  the  flint  pow- 
der sprinkled  into  the  liquid,  as  long  as 
it  dissolves  with  effervescence.  The  mass 
is  to  be  then  allowed  to  cool,  dissolved  in 
dilute  muriatic  acid ;  the  solution  is  to 
be  filtered,  and  evaporated  to  dryness; 
the  dry  crust  is  to  be  pulverized,  digested 
for  two  hours  with  a  little  muriatic  acid, 
to  remove  any  iron  and  alumina  that  may 
be  present,  next  washed  with  hot  water, 
drained,  dried,  and  ignited. 

The  above  silicate  of  potassa  and  soda 
is  the  compound  called  soluble  glass, 
which  applied  in  solution  to  the  surface 
of  wood,  calico,  paper,  &c,  renders  them 
unsusceptible  ot  taking  fire  on  the  con- 
tact of  an  ignited  body. 

Silica,  as  thus  prepared,  is  a  white  pow- 
der, rough  to  the  touch,  gritty  between 
the  teeth,  absolutely  insoluble  in  water, 
acids,  and  most  liquids.  Its  specific  gra- 
vity is  2-66.  It  cannot  be  fused  by  the 
most  intense  heat  of  our  furnaces,  but  at 
the  flame  of  the  oxy-hydrogen  blowpipe 
it  melts  into  a  limpid  colorless  glass.  By 
peculiar  chemical  methods,  an  aqueous 
solution  of  It  may  be  made  artificially,  si- 
milar to  what  nature  presents  us  with  in 
many  thermal  springs,  as  in  those  of 
Reikum  and  of  Geyser  in  Iceland,  and  of 
most  mineral  waters,  in  minute  quantity. 
There  is  no  acid  except  the  fluoric  which 
can  directly  dissolve  dry  or  calcined  sili- 
ca. Silica  is  composed  of  48-04  silicon, 
and  51-96  oxygen. 

SILICATES  are  compounds  of  silicic 
acid  (silica),  with  the  bases  alumina, 
lime,  magnesia,  potassa,  soda,  &c.  They 
constitute  the  greater  number  by  far  of 
the  hard  minerals  which  incrust  the  ter- 
restrial globe.  Thus  cyanite  is  a  subsili- 
cate  of  alumina;  feldspar  and  leucitc,  are 
silicates  of  alumina  and  potassa ;  albite 
and  analcime,  are  silicates  of  alumina  and 
soda ;  stilbite,  prehnite,  mesolite,  labra- 
dorite,  tourmaline,  mica,  &c,  are  sili- 
cates of  alumina  and  lime  ;  chrysolite, 
steatite,  serpentine,  and  meerschaum,  are 
silicates  of  magnesia;  augite  and  horn- 
blende, are  silicates  of  lime  and  magne- 
sia, &c. 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


567 


SILK.  A  fine  glossy  thread  or  fila- 
ment spun  by  various  species  of  cater- 
pillars or  larvae  of  the  Phalcena  genus. 
Of  these,  the  Phalcsna  atlas  produces  the 
greatest  quantity  ;  but  the  Phalcenabom- 
byx.  is  that  commonly  employed  for  this 
purpose  in  Europe.  The  silkworm,  in 
its  caterpillar  state,  which  may  be  con- 
sidered as  the  first  stage  of  its  existence, 
after  acquiring  its  foil  growth  (about 
three  inches  in  length),  proceeds  to  en- 
close itself  in  an  oval-shaped  ball,  or  co- 
coon, which  is  formed  by  an  exceedingly 
slender  and  long  filament  of  fine  yellow 
silk,  emitted  from  the  stomach  of  the  in- 
sect preparatory  to  its  assuming  the  shapes 
of  the  chrysalis  and  moth.  In  this  latter 
stage,  after  emancipating  itself  from  its 
silken  prison,  it  seeks  its  mate,  which  has 
undergone  a  similar  transformation ;  and 
in  two  or  three  days  afterwards,  the  fe- 
male having  deposited  her  eggs  (from 
300  to  500  in  number),  both  insects  ter- 
minate their  existence.  According  to 
Beaumur,  the  phalcena  is  not  the  only  in- 
sect that  affords  this  material — several 
species  of  the  aranea,  or  spider,  enclose 
their  eggs  in  very  fine  silk. 

Raw  silk  is  produced  by  the  operation 
of  winding  off,  at  the  same  time,  several 
of  the  balls  or  cocoons  (which'  are  im- 
mersed in  warm  water,  to  soften  the  natu- 
ral gum  on  the  filament)  on  a  common 
reel,  thereby  forming  one  smooth  even 
thread.  When  the  skein  is  dry,  it  is 
taken  from  the  reel  and  made  up  into 
hanks ;  but  before  it  is  fit  for  weaving, 
and  in  order  to  enable  it  to  undergo  the 
process  of  dyeing,  without  furring  up  or 
separating  the  fibres,  it  is  converted  into 
one  of  three  forms — viz.  singles,  tram,  or 
organzine. 

Singles  (a  collective  noun)  is  formed  of 
one  of  the  reeled  threads,  being  twisted, 
in  order  to  give  it  strength  and  firmness. 

Tram  is  formed  of  two  or  more  threads 
twisted  together.  In  this  state  it  is  com- 
monly used  in  weaving,  as  the  shoot  or 
weft. 

Thrown  silk  is  formed  of  two,  three,  or 
more  singles,  according  to  the  substance 
required,  being  twisted  together  in  a  con- 
trary direction  to  that  in  which  the  sin- 
gles of  which  it  is  composed  are  twist 
ed.  This  is  termed  organzininq ;  and 
the  silk  so  twisted,  organzine.  Tlv:  art 
of  throwing  was  originally  confined  to 
Italy,  where  it  was  kept  a  secret  for  a 
long  period. 

Silk  is  commencing  to  be  cultivated 
very  extensively  in  this  country.     One  of 


the  most  successful  growers  is  Mr.  By- 
ram,  Brandenburg,  Meade  co.,  Kentucky. 

Experience  has  fully  proved  that  the 
climate  of  the  United  States  is  as  well 
adapted  to  the  nature  and  habits  of  the 
silk-worm  and  the  production  of  silk,  as 
that  of  any  other  country.  Several  va- 
rieties of  the  mulberry  being  indigenous 
in  our  soil,  and  those  generally  used  in 
the  native  country  of  the  silk-worm  suc- 
ceed equally  well  in  our  own  soil  and  cli- 
mate. Hence,  from  the  nature  and  ha- 
bits of  the  American  people,  we  must 
soon  become  the  greatest  silk-growing 
nation  on  the  earth. 

The  first  step  towards  the  production 
of  silk,  is  to  secure  a  supply  of  suitable 
food  for  the  silk-worm. 

Having  tried  all  the  varieties  introduc- 
ed into  our  country,  Mr.  Byram  finds  the 
morus  multicaulis'and  the'Canton  varie- 
ties, all  things  considered,  most  suitable 
for  that  purpose. 

At  Economy,  Pennsylvania,  the  rearing 
of  the  silk-worm  is  now  carried  on  to  a 
great  extent  and  more  successfully  than 
in  any  other  part  of  the  United  States,  or 
perhaps  in  the  world.  Their  houses  are 
two  stories  high.  The  worms  are  fed  on 
small  trays  about  eighteen  or  twenty 
inches  wide,  and  about  three  feet  long. 
The3r  are  supported  on  frames  or  hur- 
dles one  above  the  other,  and  are  about 
six  inches  apart.  When  the  worms  are 
about  ready  to  wind,  they  are  trans- 
ferred to  the  upper  story,  to  permanent 
shelves,  about  16  inches  apart,  where 
they  form  their  cocoons  in  bunches  of 
straw  placed  upright  between  the  shelves. 
The  worms  are  cleaned  at  least  once  after 
every  moulting,  and  after  the  last,  every 
day.  For  this  purpose  they  have  nets 
wove  or  knit,  of  cotton  twine,  something 
larger  than  the  size  of  the  trays,  with 
meshes  of  various  sizes  suited  to  the  age 
of  the  worms.  For  the  last  age  they  are 
about  three-quarters  of  an  inch  square. 
These  are  used  without  frames.  When 
it  is  required  to  remove  the  woims  from 
their  litter,  the  nets  are  laid  lightly  over 
them,  and  then  plentifully  fed.  When 
the  worms  have  arisen  upon  the  fresh 
leaves,  they  are  removed  by  two  persons 
taking  hold  of  the  four  corners  of  the  net 
and  transferring  them  to  clean  trays,  held 
and  carried  oft'  by  a  third  person.  One 
hundred  thousand  are  changed  in  this 
manner  in  two  hours. 

The  silk-worm  is  a  species  of  caterpil- 
lar, whose  life  is  one  continual  succession 
of  changes,  which,  in  due  time,  bocomes 


568 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sn 


a  moth  or  -winged  insect,  like  others  of 
the  genus. 

The  time  occupied  in  going  through  its 
different  forms  of  existence  varies  in  dif- 
ferent countries — governed  by  climate, 
temperature,  aud  the  quality  and  quanti- 
ty of  the  food  upon  which  it  is  fed,  and 
the  nature  of  the  particular  variety  of  the 
insect. 

The  worm  changes  or  casts  its  skin  (of 
the  common  varieties)  four  times  before 
it  attains  its  full  growth.  These  changes 
are  called  moultings,  and  the  periods  in- 
tervening between  the  several  moultings 
are  termed  ages.  When  it  is  first  hatch- 
ed it  is  of  a  blackish  color,  which  after- 
wards becomes  lighter,  varying  almost 
daily  to  different  shades,  and  in  different 
varieties  through  every  age,  to  the  close 
of  the  last,  or  near  the  time  of  spinning, 
when  it  assumes  a  grayish  yellow  semi- 
transparent  appearance. 

The  following  directions  given  by  Mr. 
J.  McHannon,  Hamilton  co.,  Ohio,  for 
the  raising  of  worms,  has  been  tried  in 
this  country,  and  is  recommended. 
First,  have  i:bod  eggs,  well  kept,  and  do 
not  let  them  hatch  till  warm  weather  or 
in  the  middle  of  May.  "When  hatched, 
lay  on  leaves,  and  move  them  on  to  clean 
paper  by  lifting  the  leaves.  Do  not  let 
them  get  too  thick  or  they  cannot  be  fed 
enough  without  covering  them  too  deep- 
ly with  leaves.  Move  and  spread  them 
every  day,  except  when  they  are  moult- 
ing. Feedx>ften  with  fresh  leaves,  give 
them  all  the  air  you  can,  so  that  they  do 
not  blow  away.  After  the  first  moulting, 
feed  with  short,  tender  twigs.  They  are 
easily  moved  and  spread  with  the  twigs 
in  the  morning  when  they  are  hungry. 
If  they  are  neglected  while  young  it  "is 
useless  to  feed  them  while  they  are  old. 
All  the  diseases  among  my  worms  are 
caused  by  neglect,  or  by  keeping  them  in 
a  close  building  where  there  was  not 
enough  pure  air.  After  they  pass  the  se- 
cond moulting,  if  they  are  fed  with  care, 
they  will  eat  the  leaves  so  clean  that  they 
will  need  to  be  moved  but  once  between 
each  moulting,  and  that  should  be  done 
just  before  they  moult ;  but  should  their 
beds  become  foul,  move  them  by  all 
means. 

Keep  each  day's  hatching  separate. 
The  first  day  but  few  worms  will  natch, 
and  they  serve  as  a  guide  for  all  the  rest. 
"When  they  commence  moulting,  you  can 
move  the  others  on  clean  papers  before 
they  commence  moulting. 

If  the  worms  are  well  fed  and  not  too 
thick  on  the  papers,  and  the  weather 


warm,  they  will  moult  nearly  at  the  same 
time ;  that  is,  each  day's  hatching,  and 
when  they  are  kept  separate  and  the  pa- 
pers marked  1st,  2d,  and  3d  day,  &c, 
you  can  feed  them  as  they  ought  to  be 
fed,  and  when  they  commence  winding 
you  can  put  up  the  bushes  for  them  to 
wind  in,  as  each  lot  commences.  They 
will  not  all  need  them  at  once  as  they 
would  if  all  ages  were  mixed.  When  all 
the  frames  commence  winding  at  once 
they  cannot  be  attended  to  in  time,  and 
many  worms  will  be  lost  if  there  is  no 
place  provided  for  them.  They  will  crawl 
over  the  frames  and  waste  their  silk ; 
even  if  they  make  a  cocoon  it  will  be  of 
but  little  value. 

After  the  third  moulting,  feed  with 
branches  as  long  as  they  will  lay  on  the 
frames.  Keep  the  bed  as  even  as  possi- 
ble. Let  no  leaves  hang  over  the  frame, 
lest  some  of  the  worms  crawl  out  on 
them,  others  will  cut  them  off,  and  leaves 
and  worms  will  fall  together  to  the 
ground. 

When  the  worms  get  too  large  to  lift 
with  the  branches,  and  they  want  moving, 
place  five  strips,  three-eighths  or  one-half 
inch  square,  across  the  frames  (the 
frames  are  three  by  four  feet,  the  strips 
are  three  feet  four  Inches  long),  so  as  to 
extend  two  inches  over  the  frame  on  each 
side.  Sift  lime  over  the  whole  bed  till  it 
is  all  white,  worms  and  all ;  then  lay 
branches  lengthwise  of  the  frame  across 
the  five  strips.  After  feeding  a  few 
times  the  worms  will  all  be  on  a  new  bed ; 
they  will  not  stay  among  the  lime  in  the 
old  bed.    They  are  then  ready  to  move. 

Have  a  few  duplicate  frames  ready ;  lay 
two  sheets  of  heavy  brown  paper  that 
will  cover  the  frame  :  if  you  could  get 
one  large  enough  to  cover  the  frame  it 
would  be  better.  Give  the  worms  a  good 
feed,  and  as  they  come  upon  the  upper 
bed,  place  two  strips,  four  feet  long,  un- 
der the  ends  of  the  five  cross  strips.  Two 
persons  can  then  raise  the  worms  up, 
while  the  third  person  slips  the  frame 
and  old  bed  out  and  places  one  of  the  du- 
plicates in  its  place.  The  worms  can  then 
be  let  down,  and  they  will  keep  eating  as 

:  if  nothing  had  happened. 

Cane  brush  is  the  best  bed  for  them  to 

J  wind  in.  When  that  cannot  be  had,  cut 
oak  limbs  ;  lay  them  in  the  sun  to  wilt : 
if  they  are  put  up  green  and  the  worm 
commences  winding  in  them  the  leaves 

!  curl  and  the  worm  has  to  leave  its  place 
to  find  a  better,  and  will  seldom  begin 
again.  Cut  the  brush  of  the  right  length 
to  spring  in  between  the  frames.    The 


ml] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


569 


frames  should  be  eighteen  inches  apart, 
three  tier,  one  above  the  other,  the  lower 
one  two  feet  from  the  ground.  When 
feeding,  after  the  brush  are  put  up,  lay 
the  butt-end  of  the  multicaulis  branches 
(nothing  else  is  worth  feeding  with) 
snug  to  the  oak  bushes,  that  the  worms 
can  get  to  them  when  they  want  to  wind. 
After  most  of  the  worms  on  a  frame  are 
gone  up,  pick  off  the  rest  and  mark  the 
frame  :  in  four  days  gather  the  cocoons, 
if  the  weather  is  warm  ;  if  not,  in  six 
days.  Having  the  oldest  worms  in  the 
upper  tier,  you  can  take  them  down  with- 
out disturbing  the  rest. 

After  the  cocoons  are  gathered,  select 
the  best  for  seed.  When  the  millers 
come  out,  throw  all  the  poor  ones  out,if 
there  are  any.  The  papers  intended  for 
the  egg^i  are  hung  up  to  keep  them  clean, 
as  there  will  be  nothing  on  them  but 
the  eggs  To  keep  eggs  from  hatching 
in  summer,  roll  the  papers  in  cotton  bat- 
ting, put  it  in  a  wooden  box  and  place 
them  in  an  ice  house  on  the  ice  ;  cover  it 
with  straw  and  they  will  keep  well.  The 
cocoons  intended  for  reeling  are  put  in 
the  sun  as  soon  as  they  are  gathered  : 
spread  them  thin,  and  a  few  days  will 
kill  the  chrysalis.  They  must  be  well 
dried  or  they  will  mould.  The  pea-nut 
being  much  firmer  and  heavier,  takes 
longer  to  kill  and  dry  than  any  other  va- 
riety. To  sum  up  the  whole  :  have  good, 
well-kept  eggs  ;  give  them  plenty  of 
room  (an  ounce  of  eggs,  when  the  worms 
ure  full  grown,  should  have  twenty-five 
frames,  three  by  four  feet,  to  feed  and 
wind  on). 

This  is  very  essential.  Keep  them 
clean ;  feed  in  an  open  building ;  close  it 
only  when  it  is  very  windy.  Cultivate 
your  trees  well ;  if  they  are  not  thrifty 
the  worms  will  not  be ;  yellow  leaves  will 
not  do.  Feed  the  worms  all  they  will  eat 
from  the  start.  It  is  better  to  have  them 
leave  some,  than  not  have  enough.  Have 
n  good  place  for  them  to  wind  in  ;  and  if 
the  weather  is  warm  and  uniform,  the 
worms  will  do  their  part.  If  any  are  dis- 
eased, pick  them  off. 

After  the  worm  has  enveloped  itself  in 
the  cocoon,  seven  or  eight  days  are  per- 
mitted to  elapse  before  the  balls  are  ga- 
thered ;  the  next  process  is  to  destroy 
the  life  of  the  chrysalides,  which  is  done 
cither  by  exposure  to  the  sun,  or  by  the 
heat  of  an  oven  or  of  steam.  The  cocoons 
are  next  separated  from  the  floss,  or 
loose  downy  substance,  which  envelopes 
the  compact  balls,  and  are  then  ready  to 
be  reeled.     For  this  purpose,  they  are  ' 


thrown  into  a  boiler  of  hot  water,  for  the 
purpose  of  dissolving  the  gum,  and,  be- 
ing gently  dressed  with  a  brush,  to  which 
the  threads  adhere,  the  reeler  is  thus 
enabled  to  disengage  them.  The  ends  of 
four  or  more  of  the  threads  thus  cleared 
are  passed  through  holes  in  an  iron  bar, 
after  which  two  of  these  compound 
threads  are  twisted  together,  and  made 
fast  to  the  reel.  The  length  of  reeled 
silk,  obtained  from  a  single  cocoon,  va- 
ries from  300  to  600  yards;  and  it  has 
been  estimated,  that  12  lbs.  of  cocoons, 
the  produce  of  the  labors  of  2,800  worms, 
who  have  consumed  152  lbs.  of  mulberry- 
leaves,  give  1  lb.  of  reeled  silk,  which  may 
be  converted  into  16  yards  of  gros  de  Na- 
ples. 

Those  cocoons  which  have  been  per- 
forated cannot  be  reeled,  but  must  be 
spun,  on  account  of  the  breaks  in  the 
thread.  The  produce  of  these  balls, 
when  worked,  is  called  fleureb. 

Heeling  is  a  branch  of'  the  silk  business, 
which  more  properly  comes  under  the 
head  of  manufacturing.  Every  farmer 
who  engages  in  the  silk  culture,  in  order 
to  avail  himself  of  an  additional  profit, 
should  provide  his  family  with  a  suitable 
reel,  by  the  use  of  which,  after  a  little 
experience,  he  will  be  enabled  to  pffer 
his  silk  in  market,  in  a  form  that  will 
greatly  enhance  its  value,  and  much  re- 
duce the  trouble  and  expense  of  trans- 
portation. Eeels  can  now  be  procured 
in  almost  any  of  the  principal  cities  at  a 
small  cost,  or  they  can  be  made  by  any 
ingenious  farmer  or  carpenter.  The  reel 
now  uniformly  used,  is  that  known  as 
the  Piedmontese. 

All  attempts  to  improve  this  reel  in  its 
general  principles,  have  failed.  At  Econ- 
omy, however,  they  have  made  an  addi- 
tion which  may  be  found  useful.  It  con- 
sists of  two  pair  of  whirls,  made  of  wire, 
in  the  form  of  an  aspel  to  a  reel,  about 
fovr  inches  long  and  two  and  a  half 
inches  across  at  the  ends,  the  wires  be- 
ing bent  in  the  middle,  leaving  them 
about  one  and  a  half  inches  across  from 
arm  to  arm,  making  the  circumference 
about  six  inches.  These  whirls  are  set 
in  an  iron  frame,  and  run  each  upon  two 
points  or  centres.  Each  pair  is  set  equi- 
distant, on  a  direct  line,  about  eight 
inches  apart,  between  the  first  guides 
and  those  on  the  traverse  bar,  instead 
of  making  the  usual  number  of  turns 
around  eiich  thread,  as  they  pass  be- 
tween the  guides  on  the  reel.  With  this 
arrangement,  each  thread  is  taken  from 
the  basin  and  passed  through  the  first 


5*70 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SIL 


guides,  then  carried  over  and  around  the 
two  whirls,  and  where  they  pass  each 
other  on  the  top,  the  turns  are  made  ne- 
cessary to  give  firmness  to  the  thread, 
then  passing  directly  through  the  guides 
in  the  traverse  bar  to  the  arms  of  the 
reel,  making  each  thread  in  reeling  in- 
dependent of  the  other.  This  enables 
the  reeler,  when  a  remnant  of  cocoons 
are  to  be  finished  on  leaving  the  work, 
to  unite  both  threads  into  one,  retaining 
the  necessarv  size ;  whereas  both  would 
be  too  fine  if  continued  on  the  reel  in 
the  ordinary  manner. 

Directions  for  reeling. — In  family  estab- 
lishments, a  common  clay  or  iron  furnace 
should  be  procured,  to  which  should  be 
fitted  a  sheet-iron  top,  about  twelve 
inches  high,  with  a  door  on  one  side, 
and  a  small  pipe  on  the  opposite  side  to 
convey  off  the  smoke;  tins  top  should 
retain  the  same  bevel  or  flare  as  the  fur- 
nace, so  as  to  be  about  twenty  inches  in 
diameter  at  the  top.  The  pan  should  be 
twenty  inches  square  and  six  inches 
deep,  divided  into  four  apartments,  two 
of  which  should  be  one  inch  larger  one 
way  than  the  other.  They  should  all 
communicate  with  each  other  at  the 
bottom. 

In  large  filiatures,  a  small  steam  engine 
to  propel  the  reels,  &c,  and  to  heat  the 
water  for  reeling  would  be  necessary. 

Before  the  operation  of  reeling  is  com- 
menced, the  cocoons  must  be  stripped  of 
their  floss,  and  assorted  into  three  sepa- 
rate parcels,  according  to  quality,  or  of 
different  degrees  of  firmness.  The  double 
cocoons  or  those  formed  by  two  or  more 
worms  spinning  together,  the  fibres  cross- 
ing each  other  and  rendering  them  diffi- 
cult to  reel ;  these  should  be  laid  aside 
to  be  manufactured  in  a  different  manner. 

After  the  cocoons  have  been  assorted 
as  above  directed,  the  operation  of  reel- 
ing may  be  commenced.  The  basin 
should  be  nearly  filled  with  the  softest 
water,  and  kept  to  a  proper  heat  by 
burning  charcoal,  or  some  other  conve- 
nient method  of  keeping  up  a  regular 
heat.  The  precise  temperature  cannot 
be  ascertained  until  the  reeling  is  com- 
menced, owing  to  the  different  qualities 
of  cocoons  ;  those  of  the  best  quality 
will  require  a  greater  degree  of  heat 
than  those  of  a  more  loose  and  open  tex- 
ture ;  hence  the  importance  of  assisting 
them.  Cocoons  also  require  less  heat, 
and  reel  much  better,  when  done  before 
the  chrysalides  are  killed,  and  the  co- 
coons become  dried. 

The  heat  of  the  water  may  be  raised 


to  near  the  boiling  point,  (it  should  never 
be  allowed  to  boil,)  when  two  or  three 
handfuls  of  cocoons  may  be  thrown  into 
one  of  the  large  apartments  of  the  basin, 
which  must  be  gently  pressed  under  wa- 
ter for  a  few  minutes,  with  a  little  brush, 
made  of  broom-corn,  with  the  ends  short- 
ened. The  heat  of  the  water  will  soon 
soften  the  gum  of  the  silk,  and  thereby 
loosen  the  ends  of  the  filaments ;  the 
reeler  should  then  gently  stir  the  cocoons 
with  the  brush,  until  the  loose  fibres  ad- 
here to  it ;  they  are  then  separated  from 
the  brush,  holding  the  filaments  in  the 
left  hand,  while  the  cocoons  are  carefully 
combed  down  between  the  fingers  of  the 
right  hand,  as  they  are  raised  out  of  the 
water.  This  is  continued  until  the  floss 
or  false  ends  are  all  drawn  off,  and  the 
fine  silk  begins  to  appear;  the  fibres  are 
then  broken  off  and  laid  over  the  edge  of 
the  basin.  The  floss  is  then  cleared  from 
the  brush  and  laid  aside  as  refuse  silk, 
and  the  operation  continued  until  most 
of  the  ends  are  thus  collected. 

If  the  silk  is  designed  for  sewings, 
about  twenty-five  fibres  should  compose 
a  thread  ;  if  intended  for  other  fabrics, 
from  eight  to  fifteen  should  be  reeled  to- 
gether. The  finer  silk  should  always  be 
reeled  from  the  best  cocoons.  The  co- 
coons composing  the  threads  are  taken 
up  in  a  small  tin  skimmer,  made  for  the 
purpose,  and  passed  from  the  large  apart- 
ment of  the  basin  to  those  directly  under 
the  guides.  As  the  ends  become'broken 
they  are  passed  back  into  the  spare  apart- 
ment, where  they  are  again  collected  to 
be  returned  to  the  reel.  The  requisite 
number  of  fibres  thus  collected  for  two 
threads  are  passed,  each,  through  the 
lower  guides.  They  are  then  wound 
around  each  other  two  or  three  times, 
and  each  carried  through  the  two  guides 
in  the  traverse  bar,  and  then  attached 
to  the  arms  of  the  reel.  The  turning 
should  now  be  commenced  with  a  slow 
and  steady  motion,  until  the  threads  run 
freely.  While  the  reel  is  turning,  the 
person  attending  the  cocoons  must  con- 
tinually be  adding  fresh  ends,  as  they 
may  be  required,  not  waiting  until  the. 
number  she  began  with  is  reduced,  be- 
cause the  internal  fibres  are  much  finer 
than  those  composing  the  external  layers. 
In  adding  new  ends,  the  reeler  must  at- 
tach them,  by  gently  pressing  them, 
with  a  little  turn  between  the  thumb  ana 
finger,  to  the  threads  as  they  arc  run- 
ning. As  the  silk  is  reeled  off,  the  chry- 
salides should  be  taken  out  of  the  basin, 
otherwise  they  obscure  and  thicken  the 


sil] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


511 


water  and  injure  the  color  and  lustre  of  i 
the  silk.  "When  the  water  becomes  dis-  j 
colored,  it  should  always  be  changed. 

If,  in  reeling,  the  silk  leaves  the  co- 
coon in  burs  or  bunches,  it  is  evident  the  | 
water  is  too  hot ;  or  when  the  ends  can- 
not be  easily  collected  with  the  brush,  or, 
when  found,  do  not  run  freely,  the  water 
is  too  cold. 

A  pail  of  cold  water  should  always  be 
at  hand,  to  be  added  to  the  basin  as  it 
may  be  required.  When  the  cocoons 
yield  their  fibres  freely,  the  reel  may  be 
turned  with  a  quicker  motion.  The 
quicker  the  motion,  the  smoother  and 
better  will  be  the  silk.  When  from  four 
to  six  ounces  have  been  reeled,  the  aspel 
may  be  taken  off,  that  the  silk  may  dry. 
The  end  should  be  fastened  so  as  to  be 
readily  found.  Squeeze  the  silk  together 
and  loosen  it  upon  the  bars ;  then  on  the 
opposite  side  tie  it  with  a  band  of  refuse 
silk  or  yarn,  then  slide  it  off  the  reel,  dou- 
ble, and  again  tie  it  near  each  exremity. 

The  quality  of  the  silk  depends  much 
upon  the  art  and  skilful  management  of 
the  reeler.  All  that  is  required  to  render 
one  perfect  in  the  art  of  reeling,  is  a  little 
practice,  accompanied  at  the  beginning 
with  a  degree  of  patience,  and  the  exer- 
cise of  judgment  in  keeping  up  the  proper 
temperature  of  water,  and  the  threads  of 
a  uniform  size. 

Manvfacture  of  perforated  cocoons. — 
The  perforated  and  double  cocoons  can 
be  manufactured  into  various  fabrics — 
such  as  stockings,  gloves,  under-shirts, 
and  the  like.  Before  the  cocoons  can  be 
spun,  they  must  be  put  into  a  clean  bag, 
made  of  some  open  cloth,  and  placed  in 
a  pot  or  kettle,  and  covered  with  soft  wa- 
ter, with  soap  (hard  or  soft)  added,  suf- 
ficient to  make  a  strong  suds,  and  boiled 
for  about  three  or  four  hours.  If  they 
are  .required  to  be  very  nice  and  white, 
the  water  may  be  changed,  and  a  small 
quantity  more  of  soap  added,  and  again 
boiled  for  a  few  minutes.  After  they  are 
boiled,  they  may  be  hung  up  and  drain- 
ed ;  they  should  then  be  rinsed  while  in 
the.  bag,  in  fair  water,  and  hung  out  to 
dry,  without  disturbing  them  in  the  bag. 
When  completely  dry,  they  may  be  spun 
on  the  common  flax  wheel,  by  first  taking 
the  cocoon  in  the  fingers,  and  slightly 
loosening  the  fibres  that  become  flatten- 
ed down  by  boiling,  and  then  spinning 
off  from  the  pierced  end.  The  silk  will 
run  entirely  off,  leaving  the  shell  bare. 

The  double  cocoons  may  be  spun  in 
the  same  manner,  but  should  be  boiled 
separately. 


SILK  MANUFACTURE.  This  may 
be  divided  into  two  branches: — 1,  the 
production  of  raw  silk;  2,  its  filature 
and  preparation  in  the  mill,  for  the  pur- 
poses of  the  weaver  and  other  textile  arti- 
sans. The  threads,  as  spun  by  the  silk- 
worm, and  wound  up  in  its  cocoon,  are 
all  twins,  in  consequence  of  the  twin  ori- 
fice in  the  nose  of  the  insect  through 
which  they  are  projected.  These  two 
threads  are  laid  parallel  to  each  other, 
and  are  glued  more  or  less  evenly  to- 
gether by  a  kind  of  glossy  varnish,  which 
also  envelopes  them,  constituting  nearly 
25  per  cent,  of  their  weight.  Each  ulti- 
mate filament  measures  about  -s-oVff  °^  an 
inch  in  average  fine  silk,  and"  the  pair 
measures  of  course  fully  y^cr  0I"an  inch. 

The  raw  silk,  before  it  can  be  used  in 
weaving,  must  be  twisted  or  thrown,  and 
may  be  converted  into  shingles,  tram,  or 
organzine.  The  first  is  produced  merely 
by  twisting  the  raw  silk,  to  give  more 
firmness  to  its  texture.  Tram  is  formed 
by  twisting  together,  but  not  very  closely^ 
two  or  more  threads  of  raw  silk,  ana 
usually  constitutes  the  weft  or  shoot  of 
manufactured  goods.  Organzine  is  prin- 
cipally used  in  the  warp,  and  is  formed 
by  twisting,  first,  each  individual  thread, 
and  then  two  or  more  of  the  threads, 
thus  twisted,  with  the  throwing-mill. 
The  silk,  when  throivn,  is  called  hard  silk, 
and  must  be  boiled,  in  order  to  discharge 
the  gum,  which,  otherwise,  renders  it 
harsh  to  the  touch,  and  unfit  to  receive 
the  dye.  After  boiling  about  four  hours 
in  soaped  water,  it  is  washed  in  clear 
water,  to  discharge  the  soap,  and  is  seen 
to  have  acquired  that  glossiness  and  soft- 
ness of  texture  which  forms  its  principal 
characteristic.  The  yarn  is  now  ready 
for  weaving. 

Silk-worms  are  fed,  in  France,  on  the 
leaves  of  the  white  mulberry,  planted  in 
hedge-rows,  as  pollards,  and  raised  from 
seeds  by  nurserymen.  The  eggs  are 
hatched  in  rooms,  heated  to  72s°  F.  One 
ounce  of  eggs  consume  1  cwt.  of  leaves, 
and  produce  from  7  to  9  lbs.  of  raw  silk, 
which  is  wound  off  the  cocoons  by  wo- 
men and  children.    The  season  is  May. 

The  silk-worm  is  now  propagated  in 
the  United  States,  and  even  so  far  north 
as  45°  there  is  a  mulberry-orchard  of  100 
acres,  and  considerable  produce  of  silk, 
8i  dollars  per  lb. 

Silk-worms  may  be  reared  with  success 
on  the  leaves  of  the  scorsonera,  or  with 
acer  tartarium. 

Satin  is  a  silk  twill  of  peculiar  descrip- 
tion, the  soft  and  lustrous  face  of  which 


572 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[SIL 


is  given  by  keeping  a  large  proportion  of 
the  threads  of  the  warp  visible.  When 
first  taken  out  of  the  loom,  satins  are 
sometimes  flossy  and  rough;  and  they 
are  dressed  by  being  rolled  on  heated 
cylinders,  which  operation  gives  the  bril- 
liant lustre. 

Watering  silk  is  performed  by  passing 
two  pieces  of  silk  placed  lengthways,  one 
on  the  other,  between  two  metallic  rol- 
lers :  the.  different  parts  are  thus  subject- 
ed to  different  degrees  of  pressure,  from 
which  the  wavy  appearance  results. 

Silk  is  embossed  by  passing  the  plain 
stuff  between  rollers ;  the  surfaces  of 
which  contain  the  desired  pattern  on  one 
cylinder,  and  on  the  other  sunk,  so  that 
the  eminences  of  the  one  coincide  with 
the  depressions  of  the  other. 

This  business,  like  all  other  branches 
of  manufacturing  industry,  has  struggled, 
in  this  country,  against  adverse  fortune, 
and  counteracted  difficulties  not  contem- 
plated by  its  early  founders.  But  we  be- 
lieve for  the  past  year  or  two  the  manu- 
facture of  sewing  silk  has  been  highly 
prosperous,  and  several  new  mills  have 
been  erected  in  different  sections  of  the 
country.  In  Tolland  county,  Conn.,  there 
are  six  factories,  which  respectively  turn 
off  the  following  amounts  of  sewing  siik 
and  twist  per  annum : — 

Vyse  &  Sons,  at  Willington, 12,000  pounds. 

Rixl'onI&  Butler,  at  Mansfield,...  5,000       " 
William  Atwood,  "         ...  3,700       " 

Zalmon,  Siorrs  &  Son,    "         ...2,000       " 
J.&E.  Hovey,  "         ...  1,500       " 

Chaffee  &  Co.,  "         ...  1,000       " 

In  addition  to  these,  we  will  enumerate 
the  remaining  establishments  which  we 
know  to  be  in  operation  in  different  sec- 
tions of  the  United  States,  with  a  proba- 
bly correct  estimate  of  the  amount  of 
goods  manufactured  per  annum  : — 

Cheney  &  Brothers,  Manchester, 
Conn., 16,000  pounds. 

A.  B.  Jones,  do.  do., 2,500       " 

Sowerhy    &    Co.,    Northampton, 

Mass, 7,000  " 

Joseph  Conani,  do.  do., 3,500  " 

,  New  Haven,  Conn.,  1,500  " 

William  Dale,  New  York  city,. . .  2,500  " 

Murray  &  Co.,  Patierson,  N.  J.,.  .10,000  " 

Livesy  &  Co.,  Canton,  Mass......  2,000  " 

B.  &  A.  Hoolev,  Philadelphia,. . .  3,000  ■ 
Brown  <fc  Co.,  Louisville,  Ky.,...  1,500  " 

SILVER.  When  pure  and  planished, 
silver  is  the  brightest  of  the  metals.  Its 
specific  gravity  in  the  ingot  is  10-47  ;  but, 
when  condensed  under  the  hammer  or 
in  the  coining  press,  it  becomes  10'6.  It 
melts  at  a  bright  red  heat,  a  temperature 


estimated  by  some  as  equal  to  1280°  Fahr., 
and  by  others  to  22°  Wedgewood.  It  is 
exceedingly  malleable  and  ductile ;  afford- 
ing leaves  not  more  than  ypflVftg  °f  an 
inch  thick,  and  wire  far  finer  than  a  hu- 
man hair. 

Its  tenacity  is,  to  that  of  gold  and  pla- 
tinum, as  the  numbers  19,  15,  and  26}  ; 
so  that  it  has  an  intermediate  strength 
between  these  two  metals.  Pure  atmos- 
pheric air  does  not  affect  silver,  but  that 
of  houses  impregnated  with  suiphureted 
hydrogen,  soon  tarnishes  it  with  a  film  of 
brown  sulphuret.  It  is  distinguished 
chemically  from  gold  and  platinum  by  its 
ready  solubility  in  nitric  acid,  and  from 
almost  all  other  metals,  by  its  saline  solu- 
tions affording  a  curdy  precipitate  with  a 
most  minute  quantity  of  sea  salt,  or  any 
soluble  chloride. 

Silver  occurs  under  many  forms  in  na- 
ture : — 

1.  Native  silver  possesses  the  greater 
part  of  the  above  properties ;  yet,  on  ac- 
count of  its  being  more  or  less  alloyed 
with  other  metals,  it  differs  a  little  in 
malleability,  lustre,  density,  &c.  It  oc- 
curs crystallized  in  wedge-form  octa- 
hedrons, in  cubes,  and  cubo-octahedrons ; 
or  in  dendritic  shapes,  and  arborescences. 
resulting  from  minute  crystals  implanted 
upon  each  ether.  But  more  usually  it 
presents  itself  in  small  grains  without 
determinable  form,  or  in  amorphous 
masses  of  various  magnitude. 

The  gangues  (mineral  matrices)  ot  na- 
tive silver  are  so  numerous,  that  it  may 
be  said  to  occur  in  all  kinds  of  rocks.  At 
one  time  it  appears  as  if  filtered  into  their 
fissures,  at  another  as  having  vegetated 
on  their  surface,  and  at  a  third,  as  if  im- 
pasted in  their  substance.  Such  varieties 
are  met  with  principally  in  the  mines  of 
Peru  and  Mexico. 

The  native  metal  is  found  in  almost  all 
the  silver  mines  now  worked ;  but  espe- 
cially in  that  of  Kongsberg  in  Norway ; 
at  Schlangenberg  in  Siberia,  in  a  sulphate 
of  barytes  ;  at  Allemont,  in  a  ferruginous 
clay,  &c. 

The  metals  most  usuallv  associated 
with  silver  in  the  native  alloy  are  gold, 
copper,  arsenic,  and  iron.  At  Andreas- 
berg  and  Guadalcanal  it  is  alloved  with 
about  5  per  cent,  of  arsenic.  The  auri- 
ferous native  silver  is  the  rarest ;  it  has 
a  brass-yellow  color. 

2.  Antimonial  silver. — This  rare  ore  is 
yellowish-blue  ;  destitute  of  malleability ; 
even  very  brittle;  spec.  grav.  9-5.  It 
melts  before  the  blowpipe,  and  affords 
white  plumes  of  oxide  ot  antimony.     It 


BJL 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


573 


consists  of  from  76  to  84  of  silver,  and 
from  24  to  16  of  antimony. 

3.  Mixed  antimoninl  silver. — At  the 
blowpipe  it  emits  a  garlic  smell.  Its  con- 
stituents are,  silver  16,  iron  44,  arsenic 
35,  antimony  4.  It  occurs  at  Andreas- 
berg. 

4.  Sulphuret  of  silver. — This  is  an 
opaque  substance,  of  a  dark-gray  or 
leaden  hue;  slightly  malleable,  and  easily 
cut  with  a  knife,  when  it  betrays  a  me- 
tallic lustre.  The  silver  is  easily  sepa- 
rated by  the  blowpipe.  It  consists  of,  13 
of  sulphur  to  89  of  silver,  by  experiment. 
Its  spec.  grav.  is  6*9.  It  occurs  crystal- 
lized in  most  silver  mines,  but  especially 
in  those  of  Freyberg,  Bohemia,  Schem- 
nitzin,  Hungary,  and  Mexico. 

5.  Red  sulphuret  of  silver  ;  silver  glance. 
—Its  spec.  erav.  is  5*7.  It  contains  from 
84  to  86  of  silver. 

6.  Sulphureted  silver,  with  bismuth. — 
Its  constituents  are  lead  35,  bismuth  27, 
silver  15,  sulphur  16,  with  a  little  iron 
and  copper.    It  is  rare. 

7.  Antimoniated  sulphuret  cf  silver,  the 
red  silver  of  many  mineralogists,  is  an 
ore  remarkable  for  its  lustre,  color,  and 
the  variety  of  its  forms.  It  is  friable, 
easily  scraped  by  the  knife,  and  affords  a 
powder  of  a  lively  crimson  red.  Its  color 
m  mass  is  brilliant  red,  dark  red,  or  even 
metallic  reddish-black.  It  crystallizes  in 
a  variety  of  forms.  Its  constituents  are — 
silver  from  56  to  62;  antimony  from  16 
to  20  ;  sulphur  from  11  to  14;  and  oxy- 
gen from  8  to  10.  The  antimony,  in  the 
state  of  a  purple  oxide  in  this  ore,  is  its 
coloring  principle.  It  is  found  in  the 
mines  ot  Freyberg,  Sainte-Marie-aux- 
Mines,  and  Guadalcanal. 

8.  Black  sulphuret  of  silver,  is  blackish, 
brittle,  cellular,  affording  globules  of  sil- 
ver at  the  blowpipe.  It  is  found  abun- 
dantly in  the  silver  mines  of  Peru  and 
Mexico.     The  Spaniards  call  it  negrillo. 

9.  Chloride  of  silver,  or  horn  silver. — 
In  consequence  of  its  semi-transparent 
aspect,  its  yellowish  or  greenish  color, 
and  such  softness  that  it  may  be  cut  with 
the  nail,  this  ore  has  been  compared  to 
horn,  and  may  be  easily  recognized.  It 
melts  at  the  flame  of  a  candle,  and  may 
be  reduced  when  heated  alonar  with  iron 
or  black  flux,  which  are  distinctive  cha- 
racters. It  is  seldom  crystallized;  but 
occurs  chiefly  in  irregular  forms,  some- 
times covering  the  native  silver  as  with  a 
thick  crust,  as  in  Peru  and  Mexico.  Its 
density  is  only  4*74. 

General  treatment  of  silver  ores. — All 
ores  which  contain  more  than  7  lbs.  of 


lead,  or  1  lb.  of  copper,  per  cent.,  are  ex- 
cluded from  the  reviving  operation,  or 
amalgamation ;  because  the  lead  would 
render  the  amalgam  very  impure,  and 
the  copper  would  be  wasted.  They  are 
sorted  tor  the  amalgamation,  in  such  a 
way,  that  the  mixture  of  the  poorer  and 
richer  ores  may  contain  4oz.  of  silver  per 
100  lbs.  The  most  usual  constituents  of 
the  ores  are,  sulphur,  silver,  antimonial 
silver,  bismuth,  sulphurets  of  arsenic,  of 
copper,  iron,  lead  (nickel,  cobalt),  zinc, 
with  several  earthy  minerals.  It  is  essen- 
tial that  the  ores  to  be  amalgamated  shall 
contain  a  certain  proportion  of  sulphur, 
in  order  that  they  may  decompose  enough 
of  sea  salt  in  the  roasting  to  disengage 
as  much  chlorine  as  to  convert  all  the 
silver  present  into  a  chloride.  "With  this 
view,  ores  poor  in  sulphur  are  mixed 
with  those  that  are  richer,  to  make  up  a 
determinate  average.  The  ore-post  is 
laid  upon  the  bed-floor,  in  a  rectangular 
heap,  about  17  ells  long,  and  4?  ells  broad 
(13  yards  and  3s);  and  upon  that  layer 
the  requisite  quantity  of  salt  is  let  down 
from  the  floor  above,  through  a  wooden 
tunnel ;  40  cwts.  of  salt  being  allotted  to 
400  cwts.  of  ore.  The  heap  being  made 
up  with  alternate  strata  to  the  desired 
magnitude,  must  be  then  well  mixed, 
and  formed  into  small  bings,  called  roast- 
posts,  weighing  each  from  Si  to  4£  cwts. 

Roasting  of  the  amalgamation  ores. — The 
furnaces  appropriated  to  the  roasting  ore- 
posts  are  ot  the  reverberatory  class,  pro- 
vided with  soot  chambers.  The  prepared 
ground  ore  is  spread  out  upon  the  hearth, 
and  dried  with  incessant  turning  over; 
then  the  fire  is  raised  so  as  to  kindle  the 
sulphur,  and  keep  the  ore  redhot  for  one 
or  two  hours  ;  during  which  time,  dense 
white-gray  vapors  of  arsenic,  antimony, 
and  water,  are  exhaled.  The  desulphur- 
ation  next  begins,  with  the  appearance  of 
a  blue  flame.  This  continues  for  three 
hours,  during  which  the  ignition  is  kept 
up.  Whenever  sulphurous  acid  ceases 
to  be  formed,  the  finishing  calcination  is 
to  be  commenced  with  increased  firing  ; 
the  object  being  now  to  decompose  the 
sea  salt  by  means  of  the  metallic  sul- 
phates that  have  been  generated,  to  con- 
vert them  into  chlorides,  with  the  simul- 
taneous production  of  sulphate  of  soda. 
The  stirring  is  to  be  continued  till  the 
proofs  taken  from  the  hearth  no  longer 
betray  the  smell  of  sulphurous,  but  only  of 
muriatic  acid  gas.  Out  of  the  nich  t  ch  am- 
bers or  soot  vaults  of  the  furnaces,  from 
96  to  100  cwts.  of  ore-dust  are  obtained, 
containing  16  lbs.  of  silver.    This  dust  is 


514 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SIL 


to  be  treated  like  unroasted  ore.  The 
fuel  of  the  first  fire  is  pitcoal ;  of  the  fin- 
ishing one,  fir-wood.  Of  the  former  115i 
cubic  feet,  and  of  the  latter,  294},  are, 
upon  an  average,  consumed  for  every 
100  cwts.  of  ore. 

During  the  last  roasting,  the  ore  in- 
creases in  bulk  by  one-fourth,  becomes 
in  consequence  a  lighter  powder,  and  of 
a  brown  color.  When  this  process  is 
completed,  the  ore  is  raked  out  upon  the 
stone  pavement,  allowed  to  cool,  then 
screened  in  close  sieve -boxes,  in  order  to 
separate  the  finer  powder  from  the  lumps. 
These  are  to  be  bruised,  mixed  with  sea 
salt,  and  subjected  to  another  calcination. 
The  finer  powder  alone  is  taken  to  the 
millstones.  The  stones  are  of  granite, 
and  make  from  100  to  120  revolutions 

Eer  minute.  The  roasted  ore,  after  it 
as  passed  through  the  bolter  of  the 
mill,  must  be  as  impalpable  as  the  finest 
flour. 

The  amalgamation. — This  is  performed 
in  horizontal  casks,  arranged  in  rows, 
each  turning  upon  a  shaft  which  passes 
through  its  axis ;  and  all  driven  by  water- 
wheels.  The  casks  are  2  feet  10  inches 
Ions-,  2  feet  8  inches  wide,  inside  mea- 
sure, and  are  provided  with  iron  ends. 
The  staves  are  3i  inches  thick,  and  are 
bound  together  with  iron  hoops.  They 
feave  a  double  bung-hole,  one  formed 
within  the  other,  secured  by  an  iron  plug 
fastened  with  screws.  They  are  filled  by 
means  of  a  wooden  spout  terminated  by 
w  canvass  hose;  through  which  10  cwts. 
of  the  bolted  ore-flour  are  introduced 
after  3  cwts.  of  water  have  been  poured 
in.  To  this  mixture,  from  *  to  &  of  a 
cwt.  of  pieces  of  iron,  li  inch  square, 
and  §  thick.  When  these  pieces  get  dis- 
solved, they  are  replaced  by  others  from 
time  to  time.  The  casks  being  two- 
thirds  full,  are  set  to  revolve  from  li  or 
2  hours,  till  the  ore-powder  and  water 
become  a  uniform  pap;  when  5  cwts. 
of  quicksilver  are  poured  into  each  of 
them.  The  casks  being:  again  made 
tight,  are  put  in  gear  with  the  driving 
machinery,  and  kept  constantly  revolv- 
ing for  14  or  16  hours,  at  the  rate  of  20 
or  22  turns  in  the  minute.  During  this 
time  they  are  twice  stopped  and  opened, 
in  order  to  see  whether  the  pap  be  of  the 
proper  consistence  ;  for  if  too  thick,  the 
globules  of  quicksilver  do  not  readily 
combine  with  the  particles  of  ore ;  and 
if  too  thin,  they  fall  and  rest  at  the  bot- 
tom. In  the  first  case,  some  water  must 
be  added ;  in  the  second,  some  ore. 
During   the    rotation,    the  temperature 


rises,   so  that  even  in  winter  it  some- 
times stands  so  high  as  104°  F. 

The  chemical  changes  which  occur  in 
the  casks  are  the  following : — The  me- 
tallic  chlorides  present  in  the  roasted  ore 
are  decomposed  by  the  iron,  whence  re- 
sults muriate  of  iron,  whilst  the  deu- 
tochloride  of  copper  is  reduced  partly  to 
protochloride,  and  partly  to  metallic 
copper,  which  throw  down  metallic  sil- 
ver. The  mercury  dissolves  the  silver, 
copper,  lead,  antimony,  into  a  complex 
amalgam.  If  the  iron  is  not  present  in 
sufficient  quantity,  or  if  it  has  not  been 
worked  with  the  ore  long  enough  to  con- 
vert the  copper  deutochloride  into  a 
protochloride,  previously  to  the  addition 
of  the  mercury,  more  or  less  of  the  last 
metal  will  be  wasted  by  its  conversion 
into  protochloride  (calomel).  The  water 
holds  in  solution  sulphate  of  soda,  unde- 
composed  sea  salt,  with  chlorides  of  iron, 
manganese,  &c. 

From  300  lbs.  of  amalgam  7  lbs.  of  im- 
pure silver  mass  is  obtained,  which 
yields  from  10  to  13  parts  out  of  16  of 
pure  silver — one-fifth  being  copper.  The 
crude  silver  is  refined  m  blacklead  cru- 
cibles, filled  within  2  inches  of  their 
brims,  and  exposed  to  a  high  heat.  The 
mass  gives  oft  vapors,  and  throws  up  a 
liquid  slag,  which  being  skimmed  oft', 
the  surface  is  to  be  strewed  over  with 
charcoal  powder,  and  covered  with  a  lid. 
The  heat  having  been  briskly  urged  for 
a  short  time,  the  charcoal  is  then  re- 
moved along  with  any  fresh  slag  that 
may  have  risen,  in  order  to  observe 
whether  the  vapors  have  ceased.  If  not, 
fresh  charcoal  must  be  again  applied,  the 
crucible  must  be  covered,  and  the  heat 
increased,  till  fumes  are  no  longer  pro- 
duced, and  the  surface  of  the  silver  be- 
comes tranquil.  Finally,  the  alloy,  which 
contains  a  little  gold  and  much  copper, 
being  now  from  11   to  13  parts  ot  fine 

j  silver  in  16  parts,  is  cast  into  iron  moulds, 
in  ingots  of  60  marcs.     The  loss  of  weight 

j  by  evaporation  and  skimming  of  the  slag 

j  amounts  to  2  per  cent. ;  the  loss  in  »il- 

!  ver  is  quite  inconsiderable. 

In  Mexico  a  new  process  has  been  in- 
troduced which  dispenses  with  amalga- 
mation. The  ore  is  converted  into  a 
chloride  by  common  salt,  which  chloride 
is  then  dissolved  by  a  solution  of  salt. 
Copper  slips  are  thrown  into  the  liquor, 
which  separate  the  silver  by  precipi- 
tation. 

Dr.  Percy,  of  England,  proposes  to 
separate  the  silver  from  the  ore  by  the 
wet  way,  using  hyposulphite  and  chloride 


sil] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


575 


of  lime :   the  process  is  recommended  as 
economical. 

Till  very  recently,  the  only  operations 
employed  for  separating  silver  from  lead 
in  the  English  smelting-works,  were  the 
following : — 

1.  Cupellation,  in  which  the  lead  was 
converted  into  a  vitreus  oxide,  which 
was  floated  off  from  the  surface  of  the 
silver. 

2.  Reduction  of  that  oxide,  commonly 
called  litharge. 

3.  Smelting  the  bottoms  of  the  cupels, 
to  extract  the  lead  which  had  soaked  into 
them,  in  a  glassy  state. 

Cupellation  and  its  two  complementary 
operations  were,  in  many  respects,  ob- 
jectionable processes  ;  from  the  injurious 
effects  of  the  lead  vapors  upon  the  health 
of  the  workmen  ;  from  the  very  consid- 
erable loss  of  metallic  lead,  amounting  to 
7  per  cent,  at  least ;  and,  lastly,  from  the 
immense  consumption  of  fuel,  as  well  as 
from  the  vast  amount  of  manual  labor  in- 
curred in  such  complicated  operations. 
Hence,  unless  the  lead  were  tolerably  rich 
in  silver,  it  would  not  bear  the  expense  of 
cupellation. 

The  patent  process  lately  introduced 
by  Mr.  Pattison,  of  Newcastle,  is  not  at 
all  prejudicial  to  the  health  of  workmen; 
it  does  not  occasion  2  per  cent,  of  loss  of 
lead,  and  in  other  respects  is  so  economi- 
cal, that  it  is  now  profitably  applied  in 
Northumberland  to  alloys  too  poor  in  sil- 
ver to  be  treated  by  cupellation.  This 
process  is  founded  on  the  following  phe- 
nomena. 

After  melting  completely  an  alloy  of 
lend  and  silver,  if  we  allow  it  to  cool  very 
slowly,  continually  stirring  it  meanwhile 
with  a  rake,  we  shall  observe  at  a  certain 
period  a  continually  increasing  number 
of  imperfect  little  crystals,  which  may  be 
taken  out  with  a  drainer,  exactly  as  we 
may  remove  the  crystals  of  sea  salt  de- 
posited during  the  concentration  of  brine, 
or  those  of  sulphate  of  soda,  as  its  agi- 
tated solution  cools.  On  submitting  to 
analysis  the  metallic  crystals  thus  sepa- 
rated, and  also  the  liquid  metal  deprived 
of  them,  we  find  the  former  to  be  lead 
almost  alone,  but  the  latter  to  be  rich  in 
silver,  when  compared  with  the  original 
alloy.  The  more  of  the  crystalline  par- 
ticles are  drained  from  the  metallic  bath, 
the  richer  does  the  mother  liquid  become 
in  silver.  In  practice,  the  poor  lead  is 
raised  by  this  means  to  the  standard  of 
the  ordinary  lead  of  the  litharge  works ; 
and  the  better  lead  is  made  ten  times 
richer.     This  very  valuable  alloy  is  then 


submitted  to  cupellation  ;  but  as  it  con- 
tains only  a  tenth  part  of  the  quantity  of 
lead  subjected  to  crystallization,  the  loes 
in  the  cupel  will  be  obviously  reduced  to 
one-tenth  of  what  it  was  by  the  formei 
process ;  that  is,  seven-tenths  of  a  per 
cent,  instead  of  seven. 

Mr.  Johnson  proposes  to  treat  the  alloy 
first  with  acetic  acid  to  lessen  the  quan- 
tity of  lead,  and  then  either  melt  it  or 
subject  it  to  cupellation. 

The  treatment  of  the  compound  ores 
of  silver  is  usually  accomplished  either 
by  roasting  or  amalgamation.  A  consid- 
erable quantity  of  silver  is  obtained  from 
argentiferous  galena.  In  fact,  almost 
every  specimen  of  native  sulphuret  of 
lead  will  be  found  to  contain  traces  of 
this  metal.  When  the  proportion  rises 
to  a  certain  amount  it  is  worth  extracting. 
The  ore  is  reduced  in  the  usual  manner, 
the  whole  of  the  silver  remaining  with 
the  lead  ;  the  latter  is  then  remelted  in  a 
large  vessel,  and  slowly  allowed  to  cool 
until  solidification  commences ;  the  por- 
tion which  first  crystallizes  is  nearly  pure 
lead,  the  alloy  with  silver  being  more 
fusible  than  lead  itself.  By  particular 
management  this  is  drained  away,  and  is 
found  to  contain  nearly  the  whole  of  the 
silver.  This  rich  mass  is  next  exposed 
to  a  red  heat  on  the  shallow  hearth  of  a 
furnace,  while  the  stream  of  air  is  allowed 
to  infringe  upon  its  surface.  Oxidation 
takes  place  with  great  rapidity :  the  fused 
oxide,  or  litharge,  being  constantly  swept 
from  the  metal  by  the  blast.  "When  the 
greater  part  of  the  lead  has  been  thus  re- 
moved, the  residue  is  transferred  to  shal- 
low dishes  made  of  bone  ash,  and  again 
heated.  The  last  of  the  lead  is  now  oxi- 
dated, and  the  oxide  sinks  in  a  melted 
state  into  the  porous  vessel,  while  the 
silver,  almost  chemically  pure  and  having 
a  brilliant  surface,  remains  behind.  (See 
Cupellation.) 

When  silver  is  melted  in  open  vessels 
it  has  the  curious  property  of  absorbing 
oxygen,  which  it  gives  out  when  it  con- 
geals. This  is  the  cause  of  the  appear- 
ance of  granular  crystallization  which  sil- 
ver assumes  when  hastily  cooled  :  a  small 
per  centage  of  copper  entirely  prevents  the 
effect.  The  only  pure  acids  which  act 
upon  silver  are  the  nitric  and  sulphuric. 
The  nitric  acid  dissolves  silver  without 
the  aid  of  heat,  nitrous  gas  is  evolved, 
and  a  dense  colorless  solution  obtained, 
from  which  tabular  crystals  of  nitrate  of 
silver  may  be  produced  by  evaporation. 
These  crystals  are  anhydrous,  and  consist 
of  118  oxide  of  silver  and  54  nitric  acid, 


576 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SLA 


the  equivalent  of  silver  being  110.  When 
melted,  and  cast  into  sticks  or  quills,  they 
form  the  lunar  caustic  of  the  surgeons. 

Chloride  of  silver  is  readily  made  by 
adding  common  salt  to  a  solution  of  ni- 
trate of  silver.  It  is  a  white  curdy  pow- 
der which  becomes  violet  when  exposed 
to  sunshine,  and  is  soluble  in  water  of 
ammonia  and  alkaline  hyposulphites. 

SILVERING.  The  covering  the  sur- 
face of  metal,  or  other  body,  with  a  bright 
coating  of  silver.  (See  Plate,  Manufac- 
ture of.) 

The  dial-plates  of  clocks,  the  scales  of 
barometers,  and  other  similar  articles,  are 
silvered  by  rubbing  upon  them  a  mixture 
of  muriate  of  silver,  sea-salt,  and  tartar, 
and  afterwards  washing  off  the  saline 
matter  with  water.  In  this  operation, 
the  silver  is  precipitated  from  the  muria- 
tic acid,  which  unites  with  part  of  the 
coppery  surface.  Silvering  of  pins  is 
effected  by  boiling  them  with  tin  filings 
and  tartar. 

To  make  sheU-siher,  silver-leaf  is  ground 
with  gum-water,  or  honey:  the  gum,  or 
honey,  is  washed  away,  and  the  powder 
which  remains  is  used  with  gum-water, 
or  white  of  eggs,  laid  on  with  a  hair- 
pencil. 

Silvering  for  looking-glasses. — L  ook  i  ng- 
glasses  are  silvered  by  an  extemporaneous 
amalgamation  of  tin  and  quicksilver. 
Tin-roil  is  placed  on  the  back  of  the  glass, 
and  some  quicksilver  is  poured  upon  it, 
and  spread  over  the  surface  with  a  hare's 
foot.  Another  glass  is  then  slid  over  the 
tin,  to  drive  off  part  of  the  quicksilver ; 
and  paper  and  a  board  being  laid  on  the 
tin,  it  is  strongly  pressed  with  a  number 
of  weights,  to  expel,  by  degrees,  the 
superfluous  quicksilver,  and  leave  only  a 
crystallized  amalgam  on  the  back  of  the 
glass. 

Mr.  Drayton,  some  years  back,  invent- 
ed a  new  mode  of  silvering,  by  using  a 
solution  of  nitrate  of  silver  in  ammonia, 
and  then  adding  a  small  quantity  of 
essential  oil,  as  that  of  cloves,  cajeput, 
&c.  By  applying  gentle  heat,  in  a  short 
time  the  silver  is  reduced  in  a  beautiful 
bright  mirror  upon  the  surface  of  the 
glass  ;  if  the  latter  surface  be  flat,  walls 
of  putty  are  necessary.  Deep  vessels 
can  have  the  solution  poured  in  and  al- 
lowed to  lay  till  deposition  takes  place. 

Silvering  for  globes. — This  amalgam  is 
made  by  dissolving  one  pound  of  tin, 
glass,  or  bismuth,  in  four  pounds  of 
quicksilver.  The  globes  to  be  silvered 
are  thoroughly  cleaned  on  the  inside, 
and  warmed;  then  the  above  amalgam 


being  heated,  so  as  to  be  perfectly  liquid, 
is  poured  in  by  a  paper  funnel,  and  the 
globe  inclined  in  various  directions,  that, 
as  the  amalgam  crystal' '"°s  by  cooling,  it 
may  adhere  to  all  pai  the  globe ;  the 

superfluous  amalgam  is  then  poured  out. 
Silvering  ivory. — Immerse  a  slip  of 
ivory  in  a  weak  solution  of  nitrate  of  sil- 
ver, and  let  it  remain  till  the  solution  has 
given  it  a  deep  yellow  color  :  then  take  it 
out  and  immerse  it  in  a  tumbler  of  clear 
water,  and  expose  it  in  water  to  the  rays 
of  the  sun.  In  about  three  hours  the 
ivory  acquires  a  black  color,  but  the 
black  surface,  on  being  rubbed,  is  soon 
changed  to  a  brilliant  silver. 

Silvering  Daguerreotype  plat-es. — Preci- 
pitate oxide  of  silver  from  the  nitrate  by 
potass*  filter,  wash,  and  dry  it.  Dis- 
solve this  oxide  in  pure  liquid  ammonia, 
the  solution  will  be  of  a  yellow  color. 
Immerse  a  slip  of  polished  copper  in  it, 
and  let  the  moisture  evaporate.  "When 
the  copper  is  quite  dry,  hold  it  over  a 
charcoal  fire ;  the  oxide  will  be  decom- 
posed, and  the  metal  reduced  on  the  cop- 
per in  the  form  of  a  complete  coating. 
This  may  be  made  beautifully  bright  by 
polishing  with  leather.  It  offers  a  much 
more  brilliant  and  smooth  surface  than 
that  of  the  last  experiment,  and  is  a  ready 
method  of  silvering  copper-plates  for  the 
Daguerreotype  pictures.  It  is  not,  how- 
ever, equally  well  performed  as  by  the  gal- 
vanic process.  (See  Electro  Metal- 
lurgy. ) 

SKEW  BRIDGE.  In  engineering,  the 
name  given  to  a  kind  of  bridge  intro- 
duced upon  railroads,  when  the  railway 
intersects  any  existing  communication  at 
right  angles.  Such  bridges  were  occa- 
sionally built  before  railroads  were  intro- 
duced; but  their  general  introduction 
has  rendered  the  use  of  skew  bridges 
universal  in  cases  where  it  may  be  neces- 
sary or  unavoidable  to  preserve  as  straight 
or  direct  a  line  as  possible. 

SLATES.  The  substances  belonging 
to  this  class  may  be  distributed  into  the 
following  species : — 

1.  Mica-slate,  occasionally  used  for  co- 
vering houses. 

2.  Clay-slate,  the  proper  roofing-slate. 
8.  "Whet-slate. 

4.  Polishing-slate. 

5.  Drawing-slate,  or  black  chalk. 

6.  Adhesive  slate. 

7.  Bituminous  shale. 

8.  Slate-clay. 

Mica-slate.— This  is  a  mountain  rock 
of  vast  continuity  and  extent,  of  a  schis- 
tose texture,  composed  of  the  minerals 


soa] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


577 


mica  and  quartz,  the  mica  being  generally 
predominant. 

Clay-slate. — This  substance  is  closely- 
connected  with  mica;  so  that  uninter- 
rupted transition:'*  lVav  be  found  between 
these  two  rocks  in  u,  ry  mountain  chains. 
It  is  a  simple  Bchi&tott  mass,  of  a  bluish- 
gray,  or  grayish-black  color,  of  various 
8 hades,  and  a  shining,  somewhat  pearly 
internal  lustre  on  the  faces,  but  of  a  dead 
color  in  the  cross  fracture. 

All  the  best  beds  of  roofing-slate  im- 
prove in  quality  as  they  lie  deeper  under 
the  surface  ;  near  to  which,  indeed,  they 
have  little  value. 

A  good  roofing  slate  should  split  read- 
ily into  thin  even  laminas ;  it  should  not 
be  absorbent  of  water  either  on  its  face 
or  endwise,  a  property  evinced  by  its  not 
increasing  perceptibly  in  weight  after  im- 
mersion in  water;  and  it  should  be  sound, 
compact,  and  not  apt  to  disintegrate. 

Some  of  the  first  qualities  ot  slate  for 
roofing,  are  now  found  in  Vermont,  near 
Brattleboro'.  It  equals  the  Welsh,  and 
somewhat  resembles  it.  It  is  also  found 
in  Worcester  co.,  Harvard,  andPepperel, 
Mass.  It  occurs  over  a  large  tract  in  N. 
Carolina.  We  see  by  Arkansas  papers 
that  a  valuable  quarry  of  it  has  just  been 
discovered  in  Eagle  Town,  in  the  Choctaw 
country.  The  slate  is  in  two  hills,  about 
a  hundred  feet  high,  which,  it  is  said,  are 
composed  wholly  of  slate. 

Slates  for  roofs,  are  trimmed,  shaped, 
and  bored  by  the  slater.  The  roof  is 
boarded  with  feather-edged  weather- 
boards, and  the  slates  are  fixed  with  cop- 
per or  zinc  nails.  A  roof  should  incline 
from  12°  to  25°.  The  best  slate  is  bluish- 
gray  ;  light-gray  is  stony  and  does  not 
shape  easily  ;  black  or  dark  absorbs  wet, 
and  quickly  decays.  They  are  for  roofs, 
from  15  inches  by  8,  to  3  feet  by  2  feet. 
The  Welsh,  Switzerland,  and  Kendal,  are 
the  best  and  largest. 

It  is  also  found  in  the  vicinity  of  Bos- 
ton, at  Charleston,  Quincy,  and  Meldon. 
Talcose  and  chlorite  slates  are  found  in 
the  New  England  states  abundantly. 
These  are  the  gangue  of  the  gold  in  the 
southern  states.  Drawing-slates  are 
found  in  Rhode  Island. 

SLEEPER.  In  architecture,  a  piece  of 
timber  whereon  are  laid  the  ground  joists 
of  a  floor.  Sleepers  are  also  pieces  of  tim- 
ber, now  rarely  used,  in  foundations 
crossed  by  planks,  &c,  and  at  right 
angles  to  them,  where  the  soil  is  bad. 
Formerly  the  term  was  used  to  denote 
the  valley  rafters  of  a  roof. 

SMALT.  A  fine  blue  color  used  in 
25 


painting  and  printing  upon  earthenware, 
and  applied  to  several  other  purposes  in 
the  arts.  The  finest  smalt  is  made  by 
fusing  glass  with  oxide  of  cobalt,  by 
which  a  very  deep  blue  compound  is  ob- 
tained, which,  when  finely  powdered, 
acquires  a  beautiful  azure  color.  Com- 
mon smalls  arc  prepared  by  fusing  mix- 
tures of  zaffre,  sand,  and  pearlash. 

SMARAGD.  In  modern  times  used 
as  a  synonym  of  emerald  (which  see) ; 
but  applied  by  the  ancients  to  various 
other  precious  stones,  such  as  fluor  spar, 
green  vitrified  lava,  green  jasper,  and 
green  glass.  The  smaragd  is  found  in 
various  parts  of  Europe,  Asia,  and  Ame- 
rica ;  but  particularly  in  the  Ural  moun- 
tains, and  in  the  mines  of  Chili  and 
Mexico. 

SMELLING  SALTS  are  usually  either 
pure  ammonia  or  its  carbonate.  Take  a 
small  piece  of  burnt  unslaked  lime,  say 
li  oz.,  and  add  to  it  in  a  mortar  1  oz.  of 
muriate  of  ammonia,  rub  them  well  to- 
gether, and  the  pungent  smell  of  ammonia- 
cal  gas  will  be  given  off;  then  bottle,  per- 
fume it,  and  cork.  The  chlorine  of  the 
sal-ammoniac  lias  a  greater  affinity  for 
lime  than  ammonia,  it  therefore  leaves 
the  ammonia  and  combines  with  the  lime, 
forming  the  chloride  of  calcium,  whilst 
the  ammoniacal  gas  is  set  at  liberty. 

SOAP.  This  useful  compound  is  ob- 
tained by  the  action  of  alkalies  upon  oily 
substances.  There  are,  accordingly,  a 
great  variety  of  soaps  ;  but  those  com- 
monly employed  may  be  considered  un- 
der the  heads  of — 1,  fine  white  soaps, 
scented  soap,  &c. ;  2,  coarse  household 
soaps ;  3,  soft  soaps.  The  materials  used 
in  the  manufacture  of  white  soaps  are 
generally  olive  oil  and  carbonate  of  soda : 
the  latter  is  rendered  caustic  by  the  oper- 
ation of  quicklime,  and  the  solution  thus 
obtained  is  called  soap  ley.  The  oil  and 
a  weak  ley  are  first  boiled  together,  and 
portions  of  stronger  ley  are  gradually 
added,  till  the  soap,  produced  by  the  mu- 
tual action  of  the  oil  and  alkali,  begins  to 
become  tenacious,  and  to  separate  from 
the  water;  some  common  salt  is  then 
generally  added  to  promote  the  granula- 
tion and  perfect  separation  of  the  soap : 
the  fire  is  then  drawn,  and  the  contents 
of  the  boiler  allowed  to  remain  for  some 
hours  at  rest,  so  that  the  soap  may  more 
completely  collect.  When  it  is  perfect  it 
is  put  into  wooden  frames  or  moulds ; 
and  when  stiff  enough  to  be  handled,  it 
is  cut  into  oblong  slices  and  dried  in  an 
airy  room.  Perfumes  are  occasionally 
added,  or  various  coloring  matters  stirred 


578 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SO  A 


in  while  the  soap  is  semifluid  to  give  it  a 
mottled  appearance.  The  Spanish  soap 
is  marbled  by  stirring  into  it  a  solution  of 
sulphate  of  iron,  which  is  decomposed 
by  the  soap,  and  black  oxide  of  iron  se- 
parated in  streaks  and  patches  through 
the  mass.  The  action  of  the  air  converts 
the  exterior  into  red  oxide,  while  the  in- 
terior long  retains  its  black  color ;  hence 
a  slice  of  this  soap  presents  a  black  mot- 
tled centre,  surrounded  by  a  reddened 
external  layer. 

Common  household  soaps  are  made 
chiefly  of  soda  and  tallow  j  or  if  potash  is 
used,  a  large  addition  ot  common  salt 
is  made  to  harden  the  soap,  which  it  pro- 
bably effects  by  the  transference  of  soda. 
Yellow  soap  has  a  portion  of  resin  added 
to  it.  Soft  soaps  are  generally  made  with 
potash  instead  of  soda,  and  fish  oil :  it 
has  a  tenacious  consistence,  and  appears 
granulated.  Soap  is  soluble  in  pure 
water  and  in  alcohol ;  the  latter  solution 
jellies  when  concentrated,  and  is  medi- 
cinally known  under  the  name  of  opodel- 
doc. When  carefully  evaporated  the  soap 
remains  in  a  gelatinous  state,  which 
forms,  when  dry,  the  article  sold  under 
the  name  of  transparent  soap. 

The  earths  and  common  metallic  oxides 
form  insoluble  soaps;  and  accordingly 
these  are  precipitated  when  earthy  and 
metallic  salts  are  added  to  solution  cf 
soap.  It  is  the  sulphate  of  lime  and  car- 
bonate of  lime  in  common  spring  water 
which  thus  render  it  unfit  for  washing, 
and  give  it  what  is  termed  hardness  ;  and, 
upon  this  principle,  a  spirituous  solution 
of  soap  is  a  simple  and  valuable  test  of 
the  fitness  of  any  river  or  spring  water 
for  the  purposes  of  the  laundry.  If  it 
merely  renders  the  water  slightly  opal- 
escent, as  is  the  case  with  rain  ana  other 
soft  waters,  it  may  be  used  for  washing ; 
but  if  it  become  milky,  it  is  usually  too 
hard  to  be  conveniently  employed ;  and 
when  one  washes  the  skin  with  hard  water, 
the  separation  of  the  insoluble  calcareous 
soap  is  extremely  disagreeable ;  it  ad- 
heres to  the  skin,  and  soils  instead  of 
cleansing  it. 

The  chemical  nature  of  soap  has  been 
laboriously  examined  by  Chevreul,  who 
has  shown  that  the  alkali  in  the  process 
of  saponification  converts  the  oil  into  pe- 
culiar acids,  as  he  terms  them  ;  the  clain 
of  the  oil  forming  oleic  acid,  and  the 
stearine  margaric^  acid :  so  tht  soluble 
soaps  are  oleates  and  margarates  of  soda 
and  potash.  He  has  enumerated  several 
other  fatty  acids  similarly  produced. 
All  new  soaps  contain  a  considerable 


'  portion  of  adhering  water,  a  great  part  ol 
|  which  they  lose  when  kept  in  a  dry  place  : 
hence  the  economy  and  excellence  of  old 
I  soap  ;  and  hence  the  dealers  in  soap  ge- 
nerally keep  it  in  a  damp  cellar,  that  it 
may  not  lose  weight  by  evaporation  ;  or. 
as  it  is  said,  sometimes  immerse  it  in 
brine,  which  does  not  dissolve  it,  but 
keeps  it  in  its  utmost  state  of  humidity. 
Soap  may  be  considered  as  a  necessary 
of  life  ;  in  all  civilized  countries  its  con- 
sumption is  immense.  According  to 
Pliny,  the  invention  of  soap  must  be 
ascribed  to  the  Gauls,  by  whom,  he  says, 
it  was  composed  of  tallow  and  ashes, 
though  the  German  soap  was  considered 
the  best. 

Liebig  has  forcibly  observed  that  we 
may  estimate  the  conditions  of  comfort 
and  civilization  of  a  nation  by  the  quan 
tity  of  soap  which  it  consumes. 

Of  the  manvfacture  of  hard  soap. — The 
fat  of  this  soap  is  usually  tallow  or  coarse 
olive  oil.  Different  species  of  grease  are 
saponified  by  soda,  with  different  degrees 
of  facility;  among  oils,  the  olive,  sweet 
almond,  rapeseed,  and  castor  oil ;  and 
among  solid  fats,  tallow,  bone  grease,  and 
butter,  are  most  easily  saponified.  From 
12  to  13  cwts.  of  tallow  are  estimated  to 
produce  one  ton  of  good  soap.  Some 
years  ago,  in  many  manufactories  the 
tallow  used  to  be  saponified  with  potash 
leys,  and  the  resulting  soft  soap  was  con- 
verted, in  the  course  of  the  process,  into 
hard  soap,  by  the  introduction  of  muriate 
of  soda,  or  weak  kelp  leys,  in  sufficient 
quantity  to  furnish  the  proper  quantity 
of  soda  by  the  reaction  of  the  potash  up- 
on the  neutral  salts.  But  the  high  price 
of  potash,  and  the  diminished  price  as 
well  as  improved  quality  of  the  crude 
sodas,  have  led  to  their  general  adoption 
in  soap-works.  The  soda-ash  used  by 
the  soap-boiler,  contains  in  general  about 
36  per  cent,  of  real  soda,  in  the  state  of 
dry  carbonate,  mixed  with  muriate  of 
soda,  and  more  or  less  undecomposed 
sulphate.  The  barilla?  from  Spain  and 
Teneriffe  contain  from  18  to  24  per  cent, 
of  real  soda. 

The  crude  soda  being  ground,  is  to  be 
stratified  with  lime  in  cylindrical  cast- 
iron  vats,  from  6  to  7  feet  wide,  and  from 
4  to  5  feet  deep ;  the  lowest  layer  con- 
sisting, of  course,  of  unslaked  or  shell 
quicklime.  The  vats  have  a  false  bottom, 
perforated  with  holes,  and  a  lateral  tubu- 
iure  under  it,  closed  commonly  with  a 
wooden  plug,  similar  to  the  cpine  of  the 
Fiench  soap  pans,  by  which  the  leys 
trickle  off  clear  and  caustic,  after  Innltra- 


soa] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


519 


tion  through  the  beds  of  lime.  The 
quantity  of  lime  must  be  proportional  to 
the  carbonic  acid  in  the  soda. 

Upon  1  ton  of  tallow  put  into  the  soap 
pan,  about  200  gallons  of  soda  ley,  of 
specific  gravity  1*040,  being  poured,"  heat 
is  applied,  and  after  a  very  gentle  ebulli- 
tion of  about  4  hours,  the  fat  will  be 
found  to  be  completely  saponified,  by  the 
test  of  the  spatula,  trowel,  or  pallet  knife ; 
for  the  fluid  ley  will  be  seen  to  separate 
at  once  upon  the  steel  blade,  from  the 
soupy  paste.  Such  leys,  if  composed  of 
pure  caustic  soda,  would  contain  4  per 
cent,  of  alkali ;  but  from  the  presence  of 
neutro-saline  matter,  they  seldom  contain 
so  much  as  2  per  cent. ;  in  fact,  a  gallon 
may  be  estimated  to  contain  not  more 
than  2  ounces ;  so  that  200  gallons  con- 
tain 25  pounds  of  real  soda.  The  fire  be- 
ing withdrawn  from  the  soap-pan,  the 
mass  is  allowed  to  cool  during  one  hour, 
or  a  little  more,  after  which  the  spent 
levs,  which  are  not  at  all  alkaline,  are  run 
off  by  a  spigot  below,  or  pumped  off 
above,  by  a  pump  set  into  the  pan.  A 
second  similar  charge  of  ley  is  now  intro- 
duced into  the  pan,  and  a  similar  boiling 
process  is  renewed.  Three  such  boils 
may  be  given  in  the  course  of  one  day's 
work,  by  an  active  soap-maker.  Next 
day  the  same  routine  is  resumed  with 
somewhat  stronger  leys,  and  so  progres- 
sively, till,  towards  the  sixth  day,  the  ley 
may  have  the  density  of  1"160,  and  wiil 
be  found  to  contain  6  per  cent,  of  real 
soda.  Were  the  ley  a  solution  of  pure 
caustic  soda,  it  would  contain  at  this 
density  no  less  than  14f  per  cent,  of  al- 
kali. The  neutro-saline  matter  present 
in  the  spent  ley  is  essential  to  the  proper 
granulation  and  separation  of  the  sapo- 
naceous compound  ;  for  otherwise  the 
watery  menstruum  would  dilute  and  even 
liquefy  the  soap.  Supposing  12?  cwts.  of 
tallow  to  yield  upon  an  average  20  cwts. 
of  hard  soap,  then  20  cwts.  of  tallow  will 
produce  32  cwts. 

Of  yellow  or  rosin  soar). — Eosin,  al- 
though very  soluble  in  alkaline  menstrua, 
is  not  however  susceptible,  like  fats,  of 
being  transformed  into  an  acid,  and  will 
not  of  course  saponify,  or  form  a  proper 
soap  by  itself.  The  more  caustic  the  al- 
kali, the  less  consistence  has  the  resin- 
ous compound  which  is  made  with  it. 
Hence  fat  of  some  kind,  in  considerable 
proportion,  must  be  used  along  with  the 
rosin,  the  minimum  being  equal  parts  ; 
and  then  the  soap  is  far  from  being  good. 
As  alkaline  matter  cannot  be  neutralized 
by  rosin,  it  preserves  its  peculiar  acri- 


mony in  a  soap  poor  in  fat,  and  is  ready 
to  act  too  powerfully  upon  woollen  and 
all  other  animal  fibres  to  which  it  is  ap- 
plied. It  is  said  that  rancid  tallow  serves 
to  mask  the  strong  odor  of  rosin  in  soap, 
more  than  any  oil  or  other  species  of  fat. 
From  what  we  have  just  said,  it  is  ob- 
viously needless  to  make  the  rosin  used 
for  yellow  soaps  pass  through  all  the 
stages  of  the  saponifying  process ;  nor 
would  this  indeed  be  proper,  as  a  portion 
of  the  rosin  would  be  carried  away,  and 
wasted  with  the  spent  leys.  The  best 
mode  of  proceeding,  therefore,  is  first  of 
all  to  make  the  hard  soap  in  the  usual 
manner,  and  at  the  last  service  or  charge 
of  ley,  namely,  when  this  ceases  to  be 
absorbed,  and  preserves  in  the  boiling- 
pan  its  entire  causticity,  to  add  the  pro- 
portion of  rosin  intended  for  the  soap. 
In  order  to  facilitate  the  solution  of  the 
rosin  in  the  soap,  it  should  be  reduced 
to  coarse  powder,  and  well  incorporated 
by  stirring  with  the  rake.  The  propor- 
tion of  rosin  is  usually  from  one-third  to 
one-fourth  the  weight  of  the  tallow.  The 
boil  must  be  kept  up  for  some  time  with 
an  excess  of  caustic  ley  ;  and  when  the 
paste  is  found,  on  cooling  a  sample  of  it, 
to  acquire  a  solid  consistence,  and  when 
diffused  in  a  little  water,  not  to  leave  a 
resinous  varnish  on  the  skin,  we  may 
consider  the  soap  to  be  finished.  We 
next  proceed  to  draw  off  the  superfluous 
leys,  and  to  purify  the  paste.  For  this 
purpose,  a  quantity  of  leys  at  80°  B.  be- 
ing poured  in,  the  mass  is  heated,  work- 
ed well  with  a  rake,  then  allowed  to  set- 
tle, and  drained  of  its  leys.  A  second 
service  of  leys,  at  4°  B.,  is  now  intro- 
duced, and  finally  one  at  2°  •  after  each 
of  which,  there  is  the  usual  agitation  and 
period  of  repose.  The  pan  being  now 
skimmed,  and  the  scum  removed  for 
another  operation,  the  soap  is  laded  off 
by  hand-pails  into  its  frame-moulds.  A 
little  palm  oil  is  usually  employed  in  the 
manufacture  of  yellow  soap,  in  order  to 
correct  the  flavor  of  the  rosin,  and 
brighten  the  color.  This  soap,  when 
well  made,  ought  to  be  of  a  fine  wax-yel- 
low hue,  be  transparent  upon  the  edges 
of  the  bars,  dissolve  readily  in  water,  and 
afford,  even  with  hard  pump- water,  an 
excellent  lather. 

The  frame-moulds  for  hard  soap  are 
composed  of  strong  wooden  bars,  made 
into  the  form  of  a  parallelogram,  which 
are  piled  over  each  other,  and  bo^nd  to- 
gether by  screwed  iron  rods,  that  pass 
down  through  them.  A  square  well  is 
thus  formed,  which  in  large  soap  facto- 


580 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sod 


ries  is  sometimes  10  feet  deep,  and  capa- 
ble of  containing  a  couple  of  tons  of  soap. 

Mr.  Sheridan  some  time  since  obtained 
a  patent  for  combining  silicate  of  soda 
with  hard  soap,  by  triturating  them  to- 
gether in  the  hot  and  pasty  state  with  a 
crutch  in  an  iron  pan.  In  this  way  from 
10  to  30  per  cent,  of  the  silicate  may  be 
introduced.  Such  soap  possesses  very 
powerful  detergent  qualities,  but  it  is  apt 
to  feel  hard  and  be  somewhat  gritty  in 
use.  The  silicated  soda  is  prepared  by 
boiling  ground  flints  in  a  strong  caustic 
ley,  till  the  specific  gravity  of  the  com- 
pound rises  to  nearly  double  the  density 
of  water.  It  then  contains  about  35  grains 
of  silica,  and  46  of  soda-hydrate,  in  100 
grains. 

Hard  soap,  after  remaining  two  days  in 
the  frames,  is  at  first  divided  horizontally 
into  parallel  tablets,  3  or  4  inches  thick, 
by  a  brass  wire ;  and  these  tablets  are 
again  cut  vertically  into  oblong  nearly 
square  bars,  called  wedges  in  Scotland. 

Dr.  Ure  examined  several  soaps,  and 
found  their  composition  somewhat  differ- 
ent.    For  instance  : — ■ 

The  foreign  Castile  soap  of  the  apothe- 
cary has  a  specific  gravity  of  1-0705,  and 
consists  of — 

Soda! 9 

Oily  fat 76-5 

Water  and  coloring-matter 14-5 

100-0 
A  perfumer's  white  soap  was  found  to 
consist  of — 

Soda 9 

Fattv  matter 75 

Water 16 

100 
A  London  cocoa-nut  oil  soap  was  found 
to  consist  of — 

Soda 4-5 

Cocoa-nut  lard 220 

Water., 73-5 

100-0 
This  remarkable  soap  was  sufficiently 
solid ;  but  it  dissolved  in  hot  water  with 
extreme  facility.    It  is  called  marine  soap, 
because  it  washes  linen  with  sea  water. 

A  poppy-nut  oil  hard  soap  consisted 
of— 

Soda 7 

Oil 76 

Water 17 

100 
Soft  soap. — The    principal    difference 
between  soaps  with  base  of  soda,  and 


I  soaps  with  base  of  potash,  depends  upon 
j  their  mode  of  combination  with  water. 
J  The  former  absorb  a  large  quantity  of  it, 
and  become  solid;  they  are  chemical 
hydrates.  The  others  experience  a  much 
feebler  cohesive  attraction  ;  but  they  re- 
tain much  more  water  in  a  state  of  mere 
mixture.  From  its  solubility,  more  alka- 
line reaction,  and  lower  price,  potash  soap 
is  preferred  for  many  purposes,  and  espe- 
cially for  scouring  woollen  yarns  and 
stuffs. 

Soft  soaps  are  usually  made  in  this 
country  and  in  England  with  whale,  seal, 
olive,  and  linseed  oils,  and  a  certain 
quantity  of  tallow ;  on  the  continent  of 
Europe,  with  the  oils  of  hempseed,  se- 
same, rapeseed,  linseed,  poppy-seed,  and 
calza ;  or  with  mixtures  of  several  of 
these  oils.  The  potash  leys  should  be 
made  perfectly  caustic,  and  of  at  least 
two  different  strengths  ;  the  weakest  be- 
ing of  specific  gravity  1-05;  and  the 
strongest,  1-20,  or  even  1-25.  A  portion 
of  the  oil  being  poured  into  the  pan,  and 
heated  to  nearly  the  boiling  point  of  wa- 
ter, a  certain  quantity  of  the  weaker  ley 
is  introduced;  the  fire  being  kept  up  so 
as  to  bring  the  mixture  to  a  boiling  state. 
Then  some  more  oil  and  ley  are  added 
alternately,  till  the  whole  quantity  of  oil 
destined  for  the  pan  is  introduced.  The 
ebulition  is  kept  up  in  the  gentlest  man- 
ner possible,  and  some  stronger  ley  is  occa- 
sionally added,  till  the  workmen  judge  the 
saponification  to  be  perfect.  The  boiling 
becomes  progressively  less  tumultuous, 
the  frothy  mass  subsides,  the  paste 
grows  transparent,  and  gradually  thick- 
ens. The  operation  is  considered  to  be 
finished  when  the  paste  ceases  to  affect 
the  tongue  with  an  acrid  pungency,  when 
all  milkiness  and  opacity  disappear,  and 
when  a  little  of  the  soap  placed  to  cool 
upon  a  glass-plate  assumes  the  proper 
consistency. 

The  exports  of  American  soap  and  tal- 
low candles  were  for  1847  and  1848  re- 
spectively, of  the  value,  in — 

1847 $606,798 

1849 $670,223 

SOAPSTONE.  (See  Steatite.) 
SODA.  Natron  ;  mineral  alkali.  This 
important  and  useful  substance  is  an 
oxide  of  sodium.  Sodium  was  discovered 
by  Davy  in  1808.  It  is  a  metal  much  re- 
sembling potassium  in  its  general  charac- 
ters. It  is  soft,  malleable,  fusible  at  li»0°, 
and  burns  when  heated  in  contact  of  air. 
"When  thrown  upon  water  it  does  not 
burn,  but  floats  about  upon  the  Burface, 


>] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


581 


and  rapidly  disappears,  being  converted 
into  soda,  which  is  dissolved  in  the  water, 
and  gives  it  an  alkaline  reaction.    The 
specific  gravity  of  sodium  is  0-97.  By  the 
quantity  of  hydrogen  evolved  during  the 
action  of  sodium  on  water,  we  learn  that 
soda,  or  oxide  of  sodium,  consists  of  1 
equivalent  of  sodium=24,  and  1  of  oxy- 
gen— 8.     The  equivalent  of  soda,  there- 
fore, is  32.     The    commercial  demands 
for  soda  are  chiefly  supplied  from  two 
sources :  the  combustion  of  marine  vege- 
tables, such  as  common  sea-weed  and  the 
aahola  soda,  which  furnish  the  impure 
alkalies  called  Tcelp  and  barilla;  and  the 
decomposition  of  common  salt,  or,  rather, 
perhaps,  of  sulphate  of  soda,  obtained  by 
the  decomposition  of  salt  by  sulphuric 
acid.      Carbonate   of  soda  forms    large 
rhombo-prismatic  crystals,  composed  of 
32   soda+22   carbonic    acid  +  90   water. 
They  fuse  in  their  water  of  crystallization 
at  about  150°,  and  it  may  be  entirely  ex- 
pelled by  exposure  to  heat.    They  efflo- 
resce when  exposed  to  air.    Sulphate  of 
soda,  or  Glauber's  salt,  is  the  result  of 
the  action  of  sulphuric  acid  upon  com- 
mon salt  {see  Muriatic  Acid.)    It  con- 
sists of  32  soda-}- 40  sulphuric  acid;  and 
the  crystals  are  constituted  of  72  dry  sul- 
phate and  90  water  :  they  are  efflorescent, 
and  soluble  in  about  three  parts  of  cold 
water.     When  sodium  is  introduced  into 
chlorine,  it  immediately  combines  with  it 
to  form  chloride  of  sodium,  or  common 
Bait;  if  heated  in  the  gas,  it  burns  very 
vividly:  24  parts  of  sodium  combine  with 
36  of  chlorine  to  form  60  parts  of  this 
important  and  well-known  compound  {see 
Salt.)   When  chlorine  gas  is  passed  into 
a  weak  solution  of  caustic  -soda  it  is  ab- 
sorbed, and  a  useful  bleaching  and  disin- 
fecting solution  is  obtained,  which  has 
been  called  Labarracque 's  disinfecting  soda 
liquid. 

Caustk  Soda — Hydrate  of  Soda. — NaO, 
HO. — This     substance    is    prepared    in 

Sractice  by  decomposing  a  somewhat 
ilute  solution  of  carbonate  of  soda  by 
hydrate  of  lime ;  the  description  of  the 
process  employed  in  the  case  of  hydrate 
of  potash,  and  the  precautions  necessary, 
apply  word  for  word  to  that  of  soda. 

The  solid  hydrate  is  a  white,  fusible 
substance,  very  similar  in  properties  to 
hydrate  of  potash.  It  is  deliquescent, 
but  dries  up  again  after  a  time  in  conse- 
quence of  the  absorption  of  carbonic 
acid.  The  solution  is  highly  alkaline, 
and  a  powerful  solvent  for  animal  matter; 
it  is  used  in  large  quantity  for  making 
soap. 


The  strength  of  a  solution  of  caustic 
soda  may  be  roughly  determined  from  a 
knowledge  of  its  density,  by  the  aid  of 
the  following  table,  drawn  up  by  Dr. 
Dalton. 


Table  of  Density. 

_.       .,                                                           Per  centage  of 
Densit>'-                                                            real  soda. 
2-00 778 

1-85  

636 

1-72 

538 

1-63 

466 

412 

1-50 

268 

1-47  

340 

1-44  

310 

140  

220 

1-36 

230 

1-32  

23  0 

1-29     

19-0 

1-23  

160 

118 

130 

1-12 

90 

1-06 

4-7 

Carbonate  of  Soda.— NaO,  COa+lOHO. 
Carbonate    01    soda    was    once      exclu- 
sivelv  obtained  from  the  ashes   of  sea- 
1  weeds,  and  of  plants,  such  as  the  salsola 
j  soda,  which  grew  by  the  sea-side,  or  be- 
ing cultivated  in  suitable  localities  for  the 
I  purpose,  were  afterwards  subjected  to  in- 
j  cineration.     The  barilla  yet  employed  in 
!  soap-making,  is  thus  produced  in  several 
!  places  on  the  coast  of  Spain,  as  Aiicant, 
Carthagena,  &e.    That  made  in  Brittany 
is  called  varec. 

Carbonate  of  soda  is  now  manufactured 
on  a  stupendous  scale  from  common  salt, 
or  rather  from  sulphate  of  soda,  by  a  pro- 
cess of  which  the  following  is  an  out- 
line— 

A  charge  of  600  lbs.  of  common  salt  is 
placed  upon  the  hearth  of  a  well-heated 
reverberatory  furnace,  and  an  equal 
weight  of  sulphuric  acid  of  sp.  gr.  1*6 
poured  upon  it  through  an  opening  in  the 
roof,  and  thoroughly  mingled  with  tho 
salt ;  hydrochloric  acid  gas  is  disengaged, 
which  is  usually  allowed  to  escape  by  the 
chimney,  and  the  salt  is  converted  into 
sulphate  of  soda.  This  part  of  the  pro- 
cess takes  for  completion  about  four 
hours,  and  requires  much  care  and  skill. 
The  sulphate  is  next  reduced  to  pow- 
der, and  mixed  with  an  equal  weight  of 
chalk  or  limestone,  and  half  as  much 
small  coal,  both  ground  or  crushed.  The 
mixture  is  thrown  into  a  reverberatory 
furnace,  and  heated  to  fusion,  with  con- 
stant stirring  ;  2  cwt.  is  about  the  quan- 
tity operated  on  at  once.  When  the  de- 
composition is  judged  complete,  the 
melted  matter  is  raked  from  the  furnace 
into    an  iron    trough,    where   it  is   al- 


582 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[sod 


lowed  to  cool.  "When  cold,  it  is  brok- 
en up  into  little  pieces  and  lixiviated 
with  cold  or  tepid  water.  The  solution 
is  evaporated  to  dryness,  and  the  salt 
calcined  with  a  little  saw-dust  in  a  suitable 
furnace.  The  product  is  the  soda-ash  of 
commerce,  which,  when  of  good  quality, 
contains  from  48  to  52  per  cent,  of  pure 
soda,  partly  in  the  state  of  carbonate,  and 
partly  as  hydrate,  the  remainder  being 
chiefly  sulphate  of  soda  and  common  salt, 
with  occasional  traces  of  sulphite  or  hy- 
posulphite, and  also  cyanide  of  sodium. 
By  dissolving  soda-ash  in  hot  water,  fil- 
tering the  solution,  and  then  allowing  it 
to  cool  slowly,  the  carbonate  is  deposited 
in  large  transparent  crystals. 

The  re-action  which'takes  place  in  the 
calcination  of  the  sulphate  with  chalk  and 
coal-dust,  seems  to  consist,  first,  in  the 
conversion  of  the  sulphate  of  soda  into 
sulphuret  of  sodium  by  the  aid  of  the 
combustible  matter,  and  secondly,  in  the 
double  interchange  of  elements  between 
that  substance  and  the  carbonate  of  lime. 
The  sulphuret  of  calcium,  thus  pro- 
duced, combines  with  another  proportion 
of  lime  to  form  a  peculiar  compound, 
which  is  insoluble  in  cold  or  slightly  warm 
water. 

Other  processes  have  been  proposed, 
and  even  carried  into  execution,  but  the 
above  is  found  most  advantageous. 

The  ordinary  crystals  of  carbonate  of 
soda  contain  10  equivalents  of  water,  but 
by  particular  management  the  same  salt 
may  be  had  with  seven  equivalents,  or 
sometimes  with  only  one — these  diflfer  in 
figure  from  the  preceding.  The  common 
form  of  the  crystal  is  derived  from  an 
oblique  rhombic  prism :  they  effloresce  in 
dry  air,  and  crumble  to  white  powder. 
Heated,  they  fuse  in  their  water  of  crys- 
tallization :  when  the  latter  has  been  ex- 
pelled, and  the  dry  salt  exposed  to  a  full 
red  heat,  it  melt's  without  undergoing 
change.  The  common  crystals  dissolve 
in  two  parts  of  cold,  and  in  less  than 
their  own  weight  of  boiling  water ;  the 
solution  has  a  strong,  disagreeable,  alka- 
line taste,  and  a  powerful  alkaline  re- 
action. 

Bicarbonate  of  Soda.— NaO,  CO'M-HO, 
CO-2. — This  salt  is  prepared  by  passing 
carbonic  acid  gas  into  a  cold  solution  of 
the  neutral  carbonate,  or  by  placing  the 
crystals  in  an  atmosphere  of  the  gas, 
which  is  rapidly  absorbed,  while  the  crys- 
tals lose  the  greater  part  of  their  water, 
and  pass  into  the  new  compound. 

Bicarbonate  of  soda,  prepared  by  either 
process,  is  a  crystalline  white  powder, 


which  cannot  be  re-dissolved  in  warm 
water  without  partial  decomposition.  It 
requires  10  parts  of  water  at  60°  for  solu- 
tion ;  the  liquid  is  feebly  alkaline  to  test- 
paper,  and  has  a  much 'milder  taste  than 
that  of  the  simple  carbonafce.  It  does  not 
precipitate  a  solution  of  magnesia.  By 
exposure  to  heat,  the  salt  is  converted 
into  neutral  carbonate. 

A  sesquicarbonate  of  soda  containing 
2NaO,  3COa  -f  4HO  has  been  described 
by  Mr.  Phillips;  like  the  sesquicarbonate 
of  potash,  it  cannot  be  formed  at  pleasure. 
This  salt  occurs  native  on  the  banks  of 
the  soda-lakes  of  Sakena  in  Africa, 
whence  it  is  exported  under  the  name  of 
Trona. 

A  new  process  for  manufacturing  bicar- 
bonate of  soda  has  been  patented  in  this 
country,  which  consists  in  exposing  the 
crude  carbonate  of  soda,  moistened  in 
trays  laid  on  shelves,  in  an  air-tight 
apartment,  into  which  steam  and  car- 
bonic acid,  from  the  flue  of  an  anthra- 
cite stove,  are  driven  in  for  7  or  10  days, 
until  the  soda  will  take  up  no  more  acid. 
It  is  then  found  that  the  soda  has  ab- 
sorbed one  half  an  equivalent  more  of 
carbonic  acid,  forming  a  sesquicarbon- 
ate. The  mass  is  taken  and  ground  to 
powder  in  a  mill.  This  substance  is  now 
used  in  making  domestic  bread,  and 
hence  is  called  bread  soda. 

SODA  ASH.  Crude  carbonate  of 
soda. 

SODA  WATER.  This  common  and 
refreshing  beverage  is,  as  usually  pre- 
pared, a  supersaturated  solution  of 
carbonic  acid  gas  in  water.  True  soda 
water  was  formerly  prepared  (and  is  still 
by  some  manufacturers)  for  medical  use. 
chiefly  as  a  remedy  for  heartburn,  and 
certain  forms  of  dyspepsia  and  calculous 
complaints ;  and  consisted  of  one,  two, 
or  three  drachms  of  carbonate  of  soda, 
dissolved  in  a  pint  of  water  highly  im- 
pregnated with  carbonic  acid.  This  is 
often  a  valuable  remedy ;  but  would 
sometimes  be  attended  by  mischievous 
results,  especially  if  indulged  in  to  the 
extent  to  which  some  persons  pursue  the 
use  of  soda  water.  The  mere  aqueous 
solution  of  carbonic  acid,  which  is  made 
by  forcing  the  gas  into  water  by  a  con- 
densing pump,  and  under  a  pressure  of 
six  or  eight  atmospheres,  is  an  agreeable 
and,  generally  speaking,  harmless  dilu- 
ent. 

In  a  strong  vessel,  whiting  or  powder- 
ed marble  is  placed,  and  dilute  oil  of 
vitriol  poured  over  it :  effervescence  im- 
mediately occurs  owing  to  the  escape  of 


sol] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


583 


carbonic  acid.  This  gas  id  conveyed  by 
pipes  into  the  vessel  containing  the  water 
to  be  impregnated,  into  which  it  is  driven 
with  so  much  force,  and  under  so  great 
pressure,  that  a  large  proportion  of  the 
gas  is  absorbed  and  retained  in  solution 
by  the  water.  When  the  pressure  is  re- 
moved, as  when  the  water  is  drawn  from 
the  fountain,  the  extra  quantity  of  gas 
held  in  solution  previously,  escapes. 

Bakewell's  apparatus  consists  of  an  ex- 
ternal casing  of  a  cylindrical  form,  with 
spherical  ends,  made  strong  enough  to 
resist  a  pressure  of  several  atmospheres. 
There  is  a  partition  about  two-thirds 
from  the  top  of  the  vessel.  The  bottom 
part  is  a  receptacle  for  the  chalk,  or  other 
suitable  material,  and  water  from  which 
the  carbonic  acid  gas  is  to  be  generated; 
then  there  is  a  vessel  containing  diluted 
sulphuric  or  muriatic  acid,  which  passes 
out  in  small  quantities,  as  required,  into 
the  vessel.  When  the  chalk  and  acid 
receptacles  are  to  be  supplied  with  those 
ingredients,  the  apparatus  is  to  be  turned 
on  its  pivots  to  a  horizontal  position. 
The  apparatus  is  then  to  be  put  into  vi- 
bration on  pivots,  by  which  the  chalk  and 
water  will  be  effectively  agitated  by  the 
motion  of  a  pendulum,  while  a  small 
portion  of  acid  yill  escape  to  keep  up 
the  generation  o-'  the  gas  as  it  passes  off 
to  the  water,  wnich  will,  at  the  same 
time,  by  the  vibration  of  the  apparatus, 
be  thoroughly  mixed  with  the  gas  as  it 
escapes  into  the  water. 

SOLDERING,  is  the  process  of  uniting 
the  surfaces  of  metals,  by  the  interven- 
tion of  a  more  fusible  metal,  which  being 
melted  upon  each  surface,  serves,  partly 
by  chemical  attraction,  and  partly  by  co- 
hesive force,  to  bind  them  together. 
The  metals  thus  united  may  be  either 
the  same  or  dissimilar ;  but  the  uniting 
metal  must  always  have  an  affinity  for 
both.  Solders  must  be,  therefore,  selected 
in  reference  to  their  appropriate  metals. 
Thus  tin-plates  are  soldered  with  an 
alloy  consisting  of  from  1  to  2  parts  of 
tin,  with  1  of  lead  ;  pewter  is  soldered 
with  a  more  fusible  alloy,  containing  a 
certain  proportion  of  bismuth  added  to 
the  lead  and  tin  ;  iron,  copper,  and  brass 
are  soldered  with  spelter,  an  alloy  of  zinc 
and  copper,  in  nearly  equal  parts';  silver, 
sometimes  with  pure  tin,  but  generally 
with  silver-solder,  an  alloy  consisting  of 
5  parts  of  silver,  6  of  brass,  and  2  of 
zinc  ;  zinc  and  lead,  with  an  alloy  of  from 
1  to  2  parts  of  lead  with  1  of  tin  ;  plati- 
num, with  fine  grold  j  gold,  with  an  alloy 
of  silver  and  gold,  or  of  copper  and  gold. 


For  the  simple  solders,  each  of  tho 
met<ils  may  be  used,  according  to  the 
nature  of  that  which  is  to  be  soldered. 
For  fine  steel,  copper,  and  brass  work, 
gold  and  silver  may  be  employed.  In  the 
large  way,  however,  iron  is  soldered  with 
copper,  and  copper  and  brass  with  tin. 
The  most  usual  solders  are  the  compound, 
which  are  distinguished  into  two  princi- 
pal classes,  viz. :  hard  and  soft  solder3. 
The  hard  solders  are  ductile,  will  bear 
hammering,  and  are  commonly  prepared 
of  the  same  metal  with  that  which  is  to 
be  soldered,  with  the  addition  of  some 
other,  by  which  a  greater  degree  of  fusi- 
bility is  obtained. 

The  hard  solder  for  gold  is  prepared 
from  gold  and  silver,  or  gold  and  copper, 
or  srold,  silver,  and  copper. 

The  hard  solder  for  silver  is  prepared 
from  equal  parts  of  silver  and  brass, 
but  made  easier  of  fusion  by  one-six- 
teenth of  zinc. 

The  hard  solder  for  brass  is  obtained 
from  brass,  mixed  with  a  sixth,  or  an 
eighth,  or  even  one  half  of  zinc,  which 
may  also  be  used  for  the  hard  solder  of 
copper.  It  is  sold  in  a  granulated  form, 
under  the  name  of  spelter  solder. 

The  soft  solders  melt  easily,  but  are 
brittle,  and  cannot  be  hammered.  Of  this 
kind  are  the  following  mixtures  : — tin 
aud  lead,  in  equal  parts;  of  still  easier 
fusion  is  that  consisting  of  bismuth,  tin, 
and  lead,  in  equal  parts  ;  one  or  two  parts 
of  bismuth,  of  tin,  and  lead,  each  one 
part, 

In  the  operation  of  soldering,  the  sur- 
faces of  the  metal  intended  to  be  joined 
must  be  made  very  clean,  and  applied  to 
each  other,  and  it  is  usual  to  secure  them 
by  a  ligature  of  iron  wire.  The  solder 
is  laid  upon  the  joint,  together  with  sal- 
ammoniac  and  borax,  or  common  glass, 
according  to  the  degrees  of  heat  intended, 
and  these  additions  defend  the  metal 
from  oxidation. 

Glaziers  use  resin  ;  and  pitch  is  some- 
times employed. 

Tin  foil,  applied  between  the  joints  of 
fine  brass  work,  first  moistened  with  a 
strong  solution  of  sal-ammoniac,  makes 
an  excellent  juncture,  care  being  taken  to 
avoid  too  much  heat. 

In  joining  lead  plates  together,  when 
solder  is  objectionable,  owing  to  corrosion 
occurring,  after  the  surfaces  have  been 
cleaned,  they  are  united  by  melting  their 
edges  together  with  the  blowpipe,  or  by 
pouring  a  band  of  melted  lead  along  the 
two  edges  placed  in  apposition.  Chloride 
of  zinc  in  solution  is  now  used  as  the 


584 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[spo 


substance  best  adapted  for  cleaning  the 
surfaces  of  metals  to  be  soldered. 

SPECIFIC  GRAVITY.  (See  Gkavttt.) 

SPECTKUM.  In  optics,  the  name  given 
to  an  elongated  image  of  the  sun  or  other 
luminous  body,  formed  on  a  wall  or 
screen  by  a  beam  of  undecomposed  light 
received  through  a  small  hole,  and  re- 
fracted by  a  prism.  For  the  different 
colors  and  fixed  lines  of  the  solar  spec- 
trum, and  for  the  refrangibility  of  the 
different  rays,  see  the  Handbook  of  Sci- 
ence, of  this  series. 

SPECULUM.  In  optics,  the  term 
speculum  is  usually  appropriated  to  re- 
flectors formed  of  polished  metal ;  while 
the  term  mirror  is  used  to  signify  a  re- 
flector of  if  lass. 

SPECULUM  METAL,  with  which 
mirrors  for  reflecting  telescopes  are  made, 
is  an  alloy  of  two  parts  of  copper  and  one 
of  tin;  its  whiteness  is  improved  by  the 
addition  of  a  little  arsenic. 

SPELTEK.     (See  Zinc.) 

SPONGE,  is  a  cellular  fibrous  tissue, 
produced  by  small  animals,  almost  im- 
perceptible, called  Polypi  by  naturalists, 
which  live  in  the  sea.  This  tissue  is  said 
to  be  covered  in  its  recent  state  with  a 
hind  of  semifluid  thin  coat  of  animal  jelly, 
susceptible  of  a  slight  contraction  or 
trembling  on  being  touched,  which  is  the 
only  symptom  of  vitality  displayed  by 
the  sponge.  After  death  this  jelly  dis- 
appears, and  leaves  merely  the  sponge ; 
formed  by  the  combinationxof  a  multitude 
of  small  capillary  tubes,  capable  of  re- 
ceiving water  in  their  interior,  and  of 
becoming  thereby  distended.  Sponges 
occur  attached  to  stones  at  the  bottom  of 
the  sea,  and  abound  particularly  upon  the 
shores  of  the  islandsin  the  Grecian  Archi- 
pelago. Although  analogous  in  their 
origin  to  coral,  sponges  are  quite  diffe- 
rent in  their  nature  ;  the  former  being 
composed  almost  entirely  of  carbonate  of 
lime,  while  the  latter  are  formed  of  the 
same  elements  as  animal  matters,  and 
afford  on  distillation  a  considerable  quan- 
tity of  ammonia. 

Dilute  sulphuric  acid  has  been  recom- 
mended for  bleaching  sponges,  after  the 
calcareous  impurities  have  been  removed 
by  muriatic  acid.  Chlorine  water  answers 
better. 

The  snonges  of  commerce  are  usually 
preparea  before  they  come  to  the  market, 
by  being  beaten  and  soaked  in  dilute 
muriatic  acid  with  a  view  to  bleach  them, 
and  to  dissolve  any  adherent  portions  of 
carbonate  of  lime.  Three  kinds  are  found 
commonly  in  the  market  and  known  as 


the  Turkey;  the  variety  of  the  same, 
which  is  very  rare  ;  and  the  West  Indian. 
On  examining  the  living  sponge  of  com- 
merce with  a  power  of  about  500  linear, 
the  fleshy  matter  will  be  distinctly  ob- 
served, having  in  its  interior  gemmae, 
which  are  considered  to  be  the  young. 
These  are  occasionally  given  off  from  the 
mass  of  living  matter.  The  greater  por- 
tion of  the  mass  of  sponge  consists  of 
small  cylindrical  threads  or  fibres,  various 
in  size.  The  spiculse  are  not  found  with- 
in these,  but  in  the  la-ge  and  flattened 
fibres,  and  varying  in  number  from  one 
to  three  or  more,  imbedded  in  their  sub- 
stance. Sometimes  one  spiculum  pro- 
jects a  half  or  more  from  the  side  of  the 
"fibre,  and  is  then  only  covered  with  the 
animal  matter  at  the  base,  or  half  way 
up.  The  fibres  of  the  West  Indian 
species  of  sponge  have  been  clearly 
proved  to  be  solid.  In  the  rare  variety 
of  Turkey  sponge,  the  fibres  are  pos- 
sessed of  vessels  which  anastomose  in 
various  directions,  differing  much  in  size, 
and  not  imbedded  in  horny  fibre,  but  in 
a  separate  sheath.  This  'true  vascular 
tissue  performs  very  important  functions 
in  the  economy  of  the  animal  during  life. 
In  some  of  the  tubes  of  sponge  have  been 
observed  small  globules,  the  largest  of 
which  measured  the  1666th  of  an  inch, 
and  the  smallest  the  50,000th  of  an  inch. 
They  were  accidentally  perceived  to  move 
from  right  to  left. 

The  rapid  strides  made  in  sponging 
within  the  Bahamas,  since  the  year  1847, 
appear  almost  incredible.  Vast  quanti- 
ties of  sponge  may  be  seen  covering 
fences,  yards,  and  housetops,  where  it  is 
left  to  dry,  after  having  been  previously 
buried  (in  order  to  kill  the  zoophyte 
which  inhabits  it)  and  washed.  It  is 
afterwards  divested  of  the  fragments  of 
rocks  which  adhere  to  it,  pressed  and 
packed  in  bales,  averaging  300 lbs.  weight, 
each,  for  the  London  market,  wh^re  it  is 
manufactured  into  cloth  hats,  &c,  and 
converted  to  many  useful  purposes. 
We  are  informed  that  it  has  recently  be- 
come the  medium  for  poultices  to  wounds 
instead  of  cloth.  From  the  1st  January 
to  June  30th,  of  the  year  1845),  there 
were  exported  nearly  1000  bales  of  sponge, 
of  the  value  of  at  feast  25  dollars  each — 
$25,000.  On  the  1st  of  January,  a  very 
small  stock  of  sponge  was  on  nana,  while 
on  the  30th  June  every  dealer  in  this 
article  had  a  large  stock ;  therefore,  as  it 
is  a  cash  article,  there  must  have  been 
paid  to  the  crews  employed  in  this  trade 
at  least  40,000  dollars. 


<i 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


585 


The  Mediterranean  at  one  time  furnish- 
ed all  the  sponges  used  in  Europe,  and 
the  very  finest  are  yet  fished  up  around 
the  Isles  of  Greece.  Our  finest  sponges 
sell  at  a  very  high  price. 

STAINED  GLASS.  Under  the  head 
of  Glass  Painting  this  subject  has  been 
already  noticed.  The  following  details 
are  additional.  The  blues  of  vitrified  co- 
lors are  all  obtained  from  the  oxide  of 
cobalt.  Cobalt  ore  (sulphuret)  being  well 
roasted  at  a  dull  red  heat,  to  dissipate  all 
the  sulphur  and  arsenic,  is  dissolved  in 
somewhat  dilute  nitric  acid,  and  after  the 
addition  of  much  water  to  the  saturated 
solution,  the  oxide  is  precipitated  by  car- 
bonate of  soda,  then  washed  upon  a  filter, 
and  dried.  The  powder  is  to  be  mixed 
with  thrice  its  weight  of  saltpetre ;  the 
mixture  is  to  be  deflagrated  in  a  crucible, 
by  applying  a  red-hot  cinder  to  it,  then 
exposed  to  the  heat  of  ignition,  washed, 
and  dried.  Three  parts  of  this  oxide  are 
to  be  mixed  with  a  flux,  consisting  of  white 
sand,  borax,  nitre,  and  a  little  chalk,  sub- 
jected to  fusion  for  an  hour,  and  then 
ground  down  into  an  enamel  powder  for 
use.  Blues  of  any  shade  or  intensity  may 
be  obtained  from  the  above,  by  mixing  it 
with  more  or  less  flux. 

The  beautiful  greenish  yellow,  of  which 
color  so  many  ornamental  glass  vessels 
have  been  lately  imported  from  Germany, 
is  made  in  Bohemia  by  the  following  pro- 
cess. Ore  of  uranium,  uran-ochre,  or 
uran-glimmer,  in  tine  powder,  being 
roasted,  and  dissolved  in  nitric  acid ;  the 
filtered  solution  is  to  be  freed  from  any 
lead  present  in  it,  by  the  cautious  addi- 
tion of  dilute  sulphuric  acid.  The  clear 
green  solution  is  to  be  evaporated  to  dry- 
ness, and  the  mass  ignited  till  it  becomes 
yellow.  One  part  of  this  oxide  is  to  be 
mixed  with  3  or  more  parts  of  a  flux, 
consisting  of  4  parts  of  red  lead  and  1  of 
ground  flints ;  the  whole  fused  together 
and  then  reduced  to  powder. 

Chrome  green. — Triturate  together  in  a 
mortar  equal  parts  of  chromate  of  potash 
and  flowers  ot  sulphur ;  put  the  mixture 
into  a  crucible  and  fuse.  Pour  out  the 
fluid  mass;  when  cool,  grind  and  wash 
well  with  water  to  remove  the  sulphuret 
of  potash  and  to  leave  the  beautiful  green 
oxide  of  chrome.  This  is  to  be  collected 
upon  a  filter,  dried,  rubbed  down  along 
with  thrice  its  weight  of  a  flux,  consist- 
ing of  4  parts  of  red  lead  and  1  part  of 
ground  flints  fused  into  a  transparent 
glass  ;  the  whole  is  now  to  be  melted  and 
afterwards  reduced  to  a  fine  powder. 

Violet. — One  part  of  calcined  black  ox- 
25* 


ide  of  manganese,  one  of  zaflfre,  ten  parts 
of  white  glass  pounded,  and  one  ot  red 
lead,  mixed,  fused,  and  ground.  Or  gold 
purple  (Cassius's  purple  precipitate)  with 
chloride  of  silver  previously  fused,  with  ten 
times  its  weight  of  a  flux,  consisting  of 
ground  quartz,  borax,  and  red  lead,  all 
melted  together ;  or,  solution  of  tin  being 
dropped  into  a  large  quantity  of  water, 
solution  of  nitrate  of  silver  may  be  first 
added,  and  then  solution  of  gold  in  aqua 
regia,  in  proper  proportions.  The  preci- 
pitate to  be  mixed  with  flux  and  fused. 

STABlOH  is  a  white  pulverulent  sub- 
stance, composed  of  microscopic  sphe- 
roids, which  are  bags  containing  the 
amylaceous  matter.  It  exists  in  a  great 
many  different  plants,  and  varies  merely 
in  the  form  and  size  of  its  microscopic 
particles ;  as  found  in  some  plants,  it 
consists  of  spherical  particles  -j-gVfr  of  an 
inch  in  diameter ;  and  in  others  of  ovoid 
particles  of  ^w  or  ^1^  of  an  inch.  It 
occurs — 1,  in  the  seeds  of  all  the  acotyle- 
dinous  plants,  among  which  are  the  seve- 
ral species  of  corns,  and  those  of  other 
graminece  ;  2,  in  the  round  perennial  tap 
roots,  which  shoot  up  an  annual  stem ; 
in  the  tuberose  roots,  such  as  potatoes, 
the  Convolvulus  batatas  and  edulis,  the 
Hellanthus  tuberosus,  the  Jatropha  mani- 
hot,  &c,  which  contain  a  great  quantity 
of  it;  3,  in  the  stems  of  several  monoco- 
tyledinous  plants,  especially  of  the  palm 
tribe,  whence  sago  comes ;  but  it  is  very 
rarely  found  in  the  stems  and  branches 
of  the  dicotyledinous  plants ;  4,  it  occurs 
in  many  species  of  lichen.  Three  kinds 
of  starch  have  been  distinguished  by 
chemists  ;  that  of  wheat,  that  called  inu- 
Une,  and  lichen  starch.  These  three 
agree  in  being  insoluble  in  cold  water, 
alcohol,  ether,  and  oils,  and  in  being  con- 
verted into  sugar  by  either  dilute  sul- 
phuric acid  or  diastase.  The  main  differ- 
ence between  them  consists  in  their  habi- 
tudes with  water  and  iodine.  The  first 
forms  with  hot  water  a  mucilaginous  so- 
lution, which  constitutes,  when  cold,  the 
paste  of  the  laundress,  and  is  tinged  blue 
by  iodine ;   the  second  forms  a  granular 

{>recipitate,  when  its  solution  in  boiling- 
lot  water  is  suffered  to  cool,  which  is 
tinged  yellow  by  iodine ;  the  third  affords, 
by  cooling  the  concentrated  solution,  a 
gelatinous  mass,  with  a  clear  liquor  float- 
ing over  it,  that  contains  little  starch. 
Its  jelly  becomes  brown-gray  with  iodine. 
1.  Ordinary  starch. — This  maybe  ex- 
tracted from  the  following  grains : — 
wheat,  rye,  barley,  oats,  buckwheat,  rice, 


586 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[STA 


maize,  millet,  spelt ;  from  the  siliquose 
seeds,  as  peas,  beans,  lentiles,  &c. ;  from 
tuberous  unci  tap  roots,  as  those  of  the  po- 
tato, the  OTchis,  manioc,  arrowroot,  batata, 
&c.  Different  kinds  of  corn  yield  very 
variable  quantities  of  starch.  Wheat 
differs  in  this  respect,  according  to  the 
varieties  of  the  plant,  as  well  as  the  soil, 
manure,  season,  and  climate. 

Wheat  partly  damaged  by  long  keep- 
lag  in  granaries,  may  be  employed  lor 
Ae  manufacture  of  starch,  as  this  consti- 
tuent suffers  less  injury  than  the  gluten; 
snd  it  may  be  used'either  in  the  ground 
or  unground  state. 

1.  With  unground  wheat. — The  wheat 
being  sifted  clean,  is  to  be  put  into  cis- 
terns, covered  with  soft  water,  and  left  to 
steep  till  it  becomes  swollen  and  so  soft 
as  to  be  easily  crushed  between  the  fin- 
gers. It  is  now  to  be  taken  out,  and  im- 
mersed in  clear  water  of  a  temperature 
equal  to  that  of  mal ting-barley,  whence  it 
is  to  be  transferred  into  bags,  which  are 
placed  in  a  wooden  chest  containing  some 
water,  and  exposed  to  strong  pressure. 
The  water  renaered  milky  by  the  starch 
being  drawn  off  by  a  tap,  fresh  water  is 
poured  in,  and  the  pressure  is  repeated. 
Instead  of  putting  the  swollen  grain  into 
bags,  some  prefer  to  grind  it  under  ver- 
tical edge-stones,  or  between  a  pair  of 
horizontal  rollers,  and  then  to  lay  it  in  a 
cistern,  and  separate  the  starchy  liquor 
by  elutriation  with  successive  quantities 
of  water  well  stirred  up  with  it.  The  re- 
siduary matter  in  the  sacks  or  cisterns 
contains  much  vegetable  albumen  and 
gluten,  along  with  the  husks ;  when  ex- 
posed to  fermentation,  it  affords  a  small 
quantity  of  starch  of  rather  inferior  quality. 

The  above  milky  liquor,  obtained  by 
expression  or  elutriation,  is  run  into  large 
cisterns,  where  it  deposits  its  starch  in 
layers  successively  less  and  less  dense ; 
the  uppermost  containing  a  considerable 

}>roportion  of  gluten.  The  supernatant 
iquor  being  drawn  off,  and  fresh  water 
poured  on  "it,  the  whole  must  be  well 
stirred  up,  allowed  again  to  settle,  and 
the  surface-liquor  again  withdrawn.  This 
washing  should  be  repeated  as  long  as 
the  water  takes  any  perceptible  color.  As 
the  first  turbid  liquor  contains  a  mixture 
of  gluten,  sugar,  gum,  albumen,  &c.,  it 
ferments  readily,  and  produces  a  certain 
portion  of  vinegar,  which  helps  to  dis- 
solve out  the  rest  of  the  mingled  gluten, 
and  thus  to  bleach  the  starch.  It  is,  in 
fact,  by  the  action  of  this  fermented  or 
soured  water,  and  repeated  washing,  that 
't  is  purified.    After  the  last  deposition 


and  decantation,  there  appears  on  the 
surface  of  the  starch  a  thin  layer  of  a 
slimy  mixture  of  gluten  and  albumen, 
which,  being  scraped  off,  serves  for  feed- 
ing pigs  of  oxen;  underneath  will  be 
found  a  starch  of  good  quality.  The  lay- 
ers of  different  sorts  are  then  taken  up 
with  a  wooden  shovel,  transferred  into 
separate  cisterns,  where  they  are  agitated 
with  water,  and  passed  through  fine 
sieves.  After  this  pap  is  once  more  well 
settled,  the  clear  water  is  drawn  off,  the 
starchy  mass  is  taken  out,  and  laid  on 
linen  cloths  in  wicker  baskets,  to  drain 
and  become  partially  dry.  When  suffi- 
ciently firm,  it  is  cut  into  pieces,  which 
are  spread  upon  other  cloths,  and  thor- 
oughly desiccated  in  a  proper  drying- 
room,  which  in  winter  is  heated  by 
stoves.  The  upper  surface  of  the  starch 
is  generally  scraped,  to  remove  any  dusty 
matter,  and  the  resulting  powder  is  sold 
in  that  state.  Wheat  yields,  upon  an 
average,  only  from  35  to  40  per  cent,  of 
good  starch.  It  should  afford  more  by 
skilful  management. 

In  1839,  M.  Pierre  Isidore  Verduer  ob- 
tained a  patent  for  making  starch,  the 
chief  object  of  which  was  to  obtain  the 
gluten  of  the  wheat  in  a  pure  state,  as  a 
suitable  ingredient  in  making  bread,  bis- 
cuits, &c.  He  works  wheat  flour  into 
dough  by  a  machine,  kneads  it,  washes 
out  the  starch  by  streams  of  cold  water, 
a  process  long  known  to  the  chemist,  and 
purifies  the  starch  by  fermentation  of  the 
superjacent  water. 

Mr.  Jones's  patent,  of  1840,  is  based 
upon  the  purification  of  the  starch  of  rice 
and  other  farinaceous  matters,  by  means 
of  caustic  alkali.  He  macerates  100  lbs. 
of  ground  rice  in  100  gallons  of  a  solution 
composed  of  200  grains  of  caustic  soda  or 
potash  to  a  gallon  of  water,  stirs  it  gra- 
dually, till  the  whole  be  well  mixed ;  after 
24  hours,  draws  off  the  superjacent  liquid 
solution  of  gluten  in  alkali,  treats  the 
starchy  deposit  with  a  fresh  quantity  of 
weak  caustic  ley,  and  thus  repeatedly, 
till  the  starch  becomes  white  and  pure. 
The  rice  before  being  ground  is  steeped 
for  some  time  in  a  like  caustic  ley,  drain- 
ed, dried,  and  sent  to  the  mill. 

Starch  is  made  from  wheat  flour  in  a 
like  way.  The  gluten  may  be  recovered 
for  use,  by  saturating  the  alkaline  solu- 
tion with  sulphuric  acid,  washing  and 
drying  the  precipitate. 

In  1841,  Mr.  W.  T.  Berger  obtained  a 
patent  for  manufacturing  starch  by  the 
agency  of  an  alkaline  salt  upon  rice.  He 
prefers  the  carbonates  of  potash  and  spda. 


8TA] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


587 


Mr.  James  Colman,  by  his  patent  in-  | 
vention  of  December,  1841,  makes  starch 
from  ground  maize  or  Indian  corn,  by 
the  agency  either  of  the  ordinary  process 
of  steeping  and  fermenting,  or  of  caustic 
or  carbonated  alkaline  leys.  He  also  pro- 
poses to  employ  dilute  muriatic  acid  to 
purify  the  starchy  matter  from  gluten,  &c. 

Mr.  Colman  has  taken  out  a  patent  re- 
cently for  an  improved  process  :  the  sub- 
joined is  the  plan  given  in  his  specifica- 
tion. Take  one  ton  of  rice,  either  whole 
or  broken,  with  or  without  the  husk,  and 
submit  it  to  the  action  of  caustic  alkaline 
ley,  in  the  manner  at  present  performed, 
using  soda  in  preference  to  potash,  as 
affording  a  less  deliquescent  product. 
Wash  the  rice  so  prepared,  and  then  pass 
it  through  the  grinding  or  levigating 
mills  in  the  usual  manner,  so  as  to  reduce 
the  starchy  matter  to  a  pulp,  in  a  fine 
state  of  division.  The  washed  pulp  so 
obtained  is  next  to  be  placed  in  a  churn, 
together  with  40  gallons  of  a  solution  pre- 
pared in  the  following  manner  : — Take 
20  lbs.  of  borax,  and  dissolve  it  in  such  a 
quantity  of  hot  or  cold  water  as  will  suf- 
fice to  form  a  cold  saturated  solution ;  for 
which  purpose  about  20  parts  of  water 
are  requisite  for  1  part  of  borax  ;  pour  40 
gallons  of  clear  solution  of  borax  thus 
made  on  a  bushel  of  unslacked  lime, 
placed  in  any  suitable  vessel ;  6tir  the 
mixture,  and  add  to  it  enough  water  to 
make  up  the  quantity  used  to  50  gallons. 
Allow  the  undissolved  portions  in  the 
mixture  to  precipitate,  draw  off  the  clear 
supernatant  solution,  and  place  it  in  the 
churn  with  the  starch  pulp,  prepared  in 
the  manner  before  mentioned.  The  con- 
tents of  the  churn  are  next  to  be  sub- 
jected to  agitation  for  two  or  three  hours, 
so  as  to  bring  each  particle  of  the  starchy 
matter  in  communication  with  the  alka- 
line solution.  When  the  desired  effect 
has  been  produced,  the  mixture  is  to  be 
run  from  the  churn  into  the  separating 
vessel,  and  about  as  much  water  as  the 
churn  will  hold  added  to  it  (dimensions 
or  capacity  of  churn  not  given);  the 
whole  is  to  be  now  well  stirred,  and  the 
starch  washed,  boxed,  and  dried  in  the 
usual  way.  Instead  of  borax  and  lime,  as 
above  mentioned,  the  same  quantity  of 
solution  of  borax  alone  may  be  used,  or 
a  solution  of  bitartrate  of  potash  and 
lime,  or  a  solution  of  bitartrate  of  potash 
alone  may  be  employed.  In  either  case, 
the  process  is  to  be  conducted  as  above 
described.  In  the  case  of  any  other  far- 
inaceous or  leguminous  substance  than 
rice  being  employed,  the  material  used 


must  be  reduced  to  a  fine  pulpy  state,  as 
in  the  case  of  rice,  proceeding  as  above 
directed. 

For  the  manufacture  of  starch  from  the 
potato,  see  Potato  Starch.  Indian 
corn  yields,  by  analysis,  over  70  per  cent, 
of  starch.  The  manufacture  of  starch 
from  corn  is  an  extensive  operation  in 
some  districts  of  this  country. 

There  are  several  other  varieties  of 
starch,  which  are  called  differently  ac- 
cording to  the  sources  whence  derived, 
as  sago  from  tapioca,  tous  le  mois, 
arrow-root,  farina,  &c. 

The  characters  of  the  different  varie- 
ties of  starch  can  be  learned  only  from 
microscopic  observation;  by  which 
means  also  their  sophistication  or  ad- 
mixture may  be  readily  ascertained. 

Starch,  from  whatever  source  obtained, 
is  a  white  soft  powder,  which  feels  crispy, 
like  flowers  of  sulphur^  when  pressed  be- 
tween the  fingers  ;  it  is  destitute  of  taste 
and  smell,  unchangeable  in  the  atmos- 
phere, and  has  a  specific  gravity  of  1*53. 
We  have  already  described  the  particles  as 
spheroids  enclosed  in  a  membrane.  The 
potato  contains  some  of  the  largest,  and 
the  millet  the  smallest.  Potato  starch 
consists  of  truncated  ovoids,  varying  in 
size  from  1- 300th  to  l-3000th  of  ah  inch; 
arrow-root,  of  ovoids  varying  in  size 
from  l-800th  to  l-2000th  of  an  inch  ; 
flour  starch,  of  insulated  globules  about 
l-lOOOth  of  an  inch  ;  cassava,  of  similar 
globules  assembled  in  groups.  These 
measurements  have  been  made  with  agood 
achromatic  microscope,  and  a  divided 
glass-slip  micrometer  of  Tully. 

For  the  saccharine  changes  which 
starch  undergoes  by  the  action  of  diastase, 
see  Fermentation. 

Lichenine,  a  species  of  starch  obtained 
from  Iceland  moss  (Cetraria.  islandica), 
as  well  as  inuline,  from  elecampane  (In- 
ula Ileleniwn),  are  rather  objects  of 
chemical  curiosity,  than  of  manufacture. 

There  is  a  kind  of  starch  made  in  order 
to  be  converted  into  gum  for  the  calico- 
printer.  This  conversion  having  been 
first  made  upon  a  great  scale  in  Eng- 
land, has  occasioned  the  product  to  be 
called  British  gum. 

A  delicate  and  ready  test  of  the  pre- 
sence of  starch  exists  in  iodine,  with 
which  the  starch  forms  a  deep  blue  color, 
or,  if  in  the  liquid  form,  a  solution  color- 
ed blue.  This  color  disappears  on  boil- 
ing, re-appears  on  cooling,  and  is  destroy- 
ed by  chlorine  and  sulphuretted  hydro- 
gen. To  produce  the  color,  the  starch 
should  be  boiled,  and  the  iodine  should 


588 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[STE 


be  free—  that  is,  not  united  to  any  other 
substance. 

STAUKOL1TE.  The  mineral  called 
cross-stone,  harmotome,  and  Andreasber- 
golite.  It  is  a  silicate  or  baryta  and 
alumina,  with  traces  of  lime  and  potash, 
and  forms  small  quadrangular  prisms 
crossing  each  other:  the  moet  character- 
istic specimens  are  from  Andreasberg,  in 
the  Hartz. 

STAUKOT1DE.  A  name  given  by 
Hauy,  and  other  mineralogists, to  the  pris- 
matic garnet,  or  grenatite.  It  occurs  in 
four  and  six-sided  prisms,  sometimes 
crossing  each  other  at  right  angles.  It  is 
a  silicate  of  alumina  and  lime,  with  the 
oxides  of  iron  and  manganese.  It  oc- 
curs in  primary  rocks,  and  is  distinguish- 
ed from  garnet  by  its  form  and  difficult 
fusibility. 

STEAM.  1.  The  vapour  of  water ;  or 
the  elastic  aeriform  fluid  generated  by 
heating  water  to  the  boiling  point.  "When 
water  m  an  open  vessel  is  heated  to  the 
temperature  of  212°,  or  to  the  boiling 
point,  globules  of  steam  are  formed  at 
the  bottom,  and  rise  to  the  surface ; 
and  the  continued  application  of  heat, 
even  though  increased  indefinitely,  will 
only  cause  a  more  copious  and  rapid 
formation  of  steam,  and  will  finally  eva- 
porate the  whole  of  the  water,  without 
raising  the  temperature  of  either.  In 
this  case,  all  the  heat  which  enters  into 
the  water  is  solely  employed  in  convert- 
ing it  into  steam  of  the  temperature  of 
boiling  water.  But  if  the  water  be  con- 
fined in  a  strong  close  vessel,  both  it  and 
the  steam  which  it  produces  may  be 
brought  to  any  temperature ;  and  as 
steam  at  212°  occupies  nearly  1700  times 
the  space  of  the  water  from  which  it  is 
generated,  it  follows  that,  when  thus 
confined,  it  must  exercise  an  enormous 
elastic  or  expansive  force  ;  which  may 
also  be  shown  to  be  proportional  to 
its  temperature.  When  the  temperature 
i9  considerably  above  212°,  the  steam 
formed  under  such  circumstances  is 
termed  high  pressure  steam  •  at  212°  it  is 
termed  low  pressure  steam,  and  its  pres- 
sure is  equal  to  that  of  the  atmosphere, 
or  15  lbs.  on  the  square  inch.  Steam  in 
its  perfect  state  is  transparent,  and  con- 
stantly invisible  ;  but  when  it  has  been 
deprived  of  part  of  its  heat  by  coming 
into  contact  with  cold  air,  it  suddenly 
assumes  a  cloudy  appearance,  and  is  con- 
densed into  water.  Hence  appears  anoth- 
er important  property  of  steam,  its  con- 
densibility ;  so  that  whenever  cold  is 
applied  to  it,  it  suddenly  returns  to  the 


liquid  state,  and  thus  can  be  employed 
to  produce  a  vacuum.  From  the  pro- 
perties above  briefly  adverted  to,  steam 
constitutes  an  invaluable  agent  for  the 
production  of  mechanical  force,  as  ex- 
emplified in  the  vast  and  multiplied  uses 
of  the  steam-engine.  Steam  is  also  em- 
ployed as  an  agent  in  distributing  the 
heat  used  for  warming  buildings,  in  heat- 
ing baths,  evaporating  solutions,  distill- 
ing, brewing,  drying,  dyeing,  and  even 
for  domestic  cookery.  It  is  also  the 
means  of  extracting  wholesome  and  nutri- 
tious food  from  most  unpromising  and 
unpalatable  substances.  2.  In  popular 
vsage,  the  visible  moist  vapour  which 
rises  from  water,  and  from  all  moist  and 
liquid  bodies,  when  subjected  to  the  ac- 
tion of  heat;  as  the  steam  of  boiling 
water,  of  malt,  of  a  tan-bed,  &c.  This 
is  properly  water  in  a  minute  state  of 
subdivision  arising  from  the  condensa- 
tion of  steam. 

History  of  Steam.  The  nature  and 
properties  of  steam  were  altogether  un- 
known to  the  ancients.  Some  accounts 
have  come  down  to  us  bearing  a  very 
early  date  of  engines  ;  such,  for  exam- 
ple, as  that  proposed  by  Hero  of  Alexan- 
dria, in  which  the  mechanical  agency  of 
steam  was  more  or  less  used  without 
any  correct  notion  of  its  mode  of  action. 
Even  at  a  much  more  recent  period  the 
eifects  produced  by  steam  were  ascribed, 
not  to  the  vapor  of  water,  but  to  the 
force  of  air  which  was  supposed  to  be 
expelled  from  water  by  heat.  In  the 
beginning  of  the  17th  century,  De  Cans 
proposed  the  construction  of  a  machine 
by  which  a  column  of  water  was  raised 
by  the  elastic  force  of  steam.  About  the 
middle  of  the  same  century,  Lord  Wor- 
cester published  the  description  of  a 
high  pressure  steam-engine,  which  has 
since  formed  so  remarkable  a  feature  in 
all  histories  of  that  machine.  Towards 
the  latter  end  of  that  century,  however, 
the  actual  properties  of  vapor  beeran  to 
be  gradually  unfolded.  In  1683,  Sir 
Samuel  Moreland  published  a  description 
of  the  force  of  steam,  in  which  he  as- 
signed very  nearly  the  exact  numerical 
proportion  in  which  water  increases  its 
volume  when  evaporated  under  the  pres- 
sure of  a  single  atmosphere.  A  few 
years  after,  Papin  discovered  the  method 
of  producing  a  vacuum  by  the  condensa- 
tion of  steam,  and  the  circumstances 
attending  its  condensation,  became  grad- 
ually better  understood,  having  been  ap- 
Slied  to  mechanical  purposes  by  Savery, 
[ewcomen,  and  others.    About  the  mid- 


bte] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


589 


die  of  the  18th  century,  the  celebrated 
Watt  applied  himself  to  the  improve- 
ment of  the  steam-engine,  and  by  various 
experiments  determined  the  relative  vol- 
umes of  steam  as  commonly  used  in 
Bteam-engines,  and  the  quantity  of  heat 
absorbed"  in  evaporation  and  evolved  in 
condensation.  About  the  same  period 
Dr.  Black  was  engaged  in  his  well-known 
investigations  respecting  the  phenomena 
of  heat,  and  had  discovered  the  pheno- 
mena and  found  the  theory  of  latent 
heat,  which  served  to  explain  the  effects 
which  Watt  had  also  observed.  The  re- 
lation between  the  temperatures  and 
pressures  of  the  vapor  of  water  was 
determined  by  Dalton,  and  confirmed  by 
Gay-Lussac,  Prof.  Robison,  Ure,  South- 
ern, and  others.  The  discovery  of  the 
law  in  virtue  of  which  the  pressure  of 
all  irises  and  vapors  increases  in  propor- 
tion to  their  density  at  a  given  tempera- 
ture was  due  to  Mariotte,  and  is  known 
as  Mariotte's  law.  The  discovery  of  the 
remarkable  fact  that  all  gases  and  vapors 
receive  the  same  increase  of  pressure  or 
volume  for  each  degree  of  temperature, 
was  first  discovered  by  Dalton ;  but  was 
immediately  afterwards  discovered  also 
by  Gay-Lussac,  who  was  not  informed  of 
Dalton's  proceedings.  _  The  most  im- 
portant course  of  experiments  which  has 
since  been  made  were  undertaken  by  a 
committee  of  the  French  Institute,  con- 
sisting of  MM.  Prony,  Arago,  Gerard, 
and  Dulong,  in  consequence  of  an  appli- 
cation from  the  French  government  to 
the  academy  to  point  out  the  best  means 
of  preventing  accidents  from  the  burst- 
ing of  the  boilers  of  steam-engines.  The 
experiments  were  conducted  chiefly  by 
Arago  and  Dulong,  and  were  certainly 
not  only  the  most  delicate  as  to  their 
management,  but  the  most  hazardous 
which  science  and  art  owe  to  the  courage 
and  zeal  of  philosophers.  Steam  was 
produced  of  a  sufficient  pressure  to  force 
a  column  of  mercury  up  a  glass  tube  to 
the  height  of  nearly  43  feet ;  an  atmos- 
phere being  measured  by  a  column  of 
mercury  measuring  29*922  inches.  Steam 
has  been  made  use  of  lately  in  many  no- 
vel modes  as  an  effective  agent  in  the 
arts,  a  remarkable  employment  of  steam 
is  in  distilling  substances  at  a  low  tem- 
perature, which  require  a  high  tempera- 
ture without  its  use.  Turpentine,  vine- 
gar, and  charcoal  may  be  mentioned.  The 
following  table  exhibits  the  temperatures 
and  corresponding  pressures  of  steam  as 
determined  by  these  experiments,  up  to 
fifty  atmospheres. 


Pressure  in 

Pressure  in 

Atmos- 

Temperature. 

Atmos- 

Temperature. 

pheres. 

pheres. 

1 

212o 

13 

380-66O 

II 

234 

14 

386  94 

2 

250-5 

15 

39286 

2* 

263  8 

16 

398-48 

3 

275  2 

17 

403-83 

3§ 

285 

18 

408  92 

4 

2937 

19 

41378 

4* 

3003 

20 

418-46 

5 

307-5 

21 

422-96 

5£ 

31424 

22 

427-28 

6 

320-36 

23 

431-42 

6.V 

326-26 

24 

435  56 

7 

33 1  7 

25 

439  34 

n 

a36-86 

30 

45716 

8 

34178 

35 

47273 

9 

350-78 

40 

486-59 

10 

358-88 

45 

49914 

11 

366-85 

50 

5106 

12 

374 

STEAM-CARRIAGE.  A  name  usual- 
ly applied  to  locomotive  engines  adapted 
to  work  on  common  roads. 

The  principle  of  the  construction  of 
these  is  in  the  general  conditions,  similar 
to  that  of  the  locomotive  engine  used  on 
railways  (see  Locomotive  Engine)  ;  but 
the  engine  adapted  to  common  roads 
must  have  the  same  power,  with  a  much 
less  weight:  or  in  other  words,  the  ratio 
of  the  weight  of  the  engine  to  the  eva- 
porating power  of  the  boiler  is  much  less 
than  in  the  case  of  railway  locomotives. 

The  first  carriage  was  that  of  Messrs. 
Trethevick  and  Vivian,  in  1802,  20  years 
after  Mr.  Griffith's  improvement.  Mr. 
Gordon,  followed  with  various  others, 
down  to  that  of  Sir  J.  Anderson,  which 
appeared  only  a  few  years  back. 

The  engine  in  steam-carriages  general- 
ly acts  either  directly  on  the  wheels,  and 
causes  them  to  revolve,  and  thereby  pro- 
pels the  carriage;  or  it  acts  on  cranks 
formed  on  the  axle  of  the  wheels,  and 
the  wheels  being  keyed  upon  the  axle 
are  compelled  to  revolve  with  it.  In 
either  case,  the  revolution,  whether  of 
the  wheels  or  the  axle,  is  produced  by  a 
connecting  rod  jointed  on  the  end  of  the 
piston  rod,  and  receiving  motion  from 
the  piston  rod.  The  wheels  are  generally 
driven  by  two  pistons  working  in  two 
cylinders,  so  that  one  is  at  its  dead  point 
when  the  other  is  in  the  position  most 
favorable  for  its  action.  The  arrange- 
ment of  this  part  of  the  machinery  being 
similar  to  that  of  the  railway  locomotive, 
need  not  be  here  more  fully  described. 

The  steam-carriages  of  different  pro- 
jectors differ  one  from  another,  chiefly 
in  the  boilers,  and  in  the  apparatus  for 


590 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[STK 


generating  the  steam  and  admitting  it  to 
the  cylinder.  Mr.  Gurney's  boiler  con- 
sisted of  a  series  of  strong  iron  tubes 
placed  side  by  side,  so  as  to  form  the 
bars  of  the  grate  of  the  furnace.  These 
were  connected  with  another  system 
nearly  at  right  angles  to  them,  forming 
the  back  of  the  furnace,  and  these  again 
with  a  third  system,  forming  the  roof 
of  the  furnace.  The  tubes  forming 
the  grate  bars  had  their  ends  inserted 
in  a  strong  iron  cylinder,  having  its  axis 
horizontal,  and  its* length  extended  across 
the  front  of  the  lurnace  under  the  fire- 
door*  and  the  tubes  forming  the  roof  of 
the  furnace  were  inserted  in  a  similar 
cylindrical  vessel,  extending  in  like  man- 
ner across  the  front  of  the  furnace  above 
the  fire-door.  These  two  cylinders  were 
likewise  connected  by  upright  cylinders 
of  less  diameter  placed  at  each  side  of 
the  fire-door.  These  systems  of  tubes 
and  cylinders  being  filled  with  water, 
the  heat  of  the  furnace  acting  on  the 
tubes  surrounding  the  fireplace,  and  the 
heated  air  and  flame  being  afterwards 
conducted  above  the  tubes  forming  the 
roof  of  the  fireplace,  before  it  escaped 
into  the  chimney,  steam  was  produced 
in  the  tubes,  which  by  its  lightness  pass- 
ed from  them  to  the  cylindrical  vessel  ex- 
tending over  the  fire-door.  From  that 
vessel  the  steam  passed  into  a  larger  cy- 
lindrical vessel  above  it,  called  a  separa- 
tor, its  purpose  being  to  disengage  the 
pure  steam  from  the  spray  of  water  with 
which  it  is  generally  mixed  when  it  first 
escapes  from  the  boiling  water  in  a  state 
of  violent  agitation. 

Every  part  of  this  boi!  jr  being  cylin- 
drical, has  the  form  whicti  is  most  favor- 
able to  strength,  and  which,  within  given  j 
dimensions,  contains  the  greatest  quan-  j 
tity  of  water.  The  tubes  surrounding  the  j 
furnace  can  freely  expand  in  the  direc-  | 
tion  of  their  length,  without  being  loos-  ! 
ened  at  the  joints,  and  without  straining  j 
any  part  of  the  apparatus.   Proper  means  | 
of  opening  the  tubes  at  their  ends  are 
provided,  by  which  they  may  be  scraped 
on  the  inside,  and  cleansed  from  any  de- 
posit which  may  be  left  in  them  by  the 
water  evaporated  in  them. 

The  boiler  must  have  the  power  of 
generating  steam  rapidly,  strength  to 
secure  it"  from  explosion,  lightness  and 
compactness.  A  strong  draft  on  the  fire 
is  produced  either  by  an  air  chamber,  or 
air  fans.  The  operation  of  steering  is 
usually  performed  by  a  hand-wheel  at 
the  forepart,  giving  motion  by  means  of 
a  rack  and  pinion,"or  chain  and  pulley  to 


the  fore  axle.  The  brake  by  which  the 
motion  of  the  steam-engine  is  arrested 
usually  consists  of  metal  bands  capable  of 
being" pressed  either  against  the  nave  or 
the  periphery  of  the  "one  or  both  the 
after  wheels. 

On  railways,  a  steam  engine  will  rea- 
dily draw  200  tons  12  miles  in  an  hour, 
which,  compared  with  ahorse  at  12  cwt., 
8  miles,  with  12  traction,  is  4000  X  12  = 
48,000  to  1152,  or  nearly  42  to  1.  Hence, 
the  engine  operates  with  the  power  of 
42  horses,  and  if  of  greater  estimated 
power,  the  difference  is  lost  in  imperfect 
contact  of  wheels,  in  friction,  &c.  If 
the  horses'  speed  were  taken  at  9  or  10 
miles,  it  would  accord  with  cruel  practi- 
ces which  ought  not  to  be  data,  that  this 
would  reduce  the  engine's  power  only  to 
35  or  36  horses. 

But  an  engine  can  work  24  hours  per 
day,  and  a  horse  but  li  hour  at  this  rate ; 
hence,  the  working  power  of  the  engine 
would  be  16  X  42,  or  672  horses. 

The  cost  is  another  consideration ;  a 
railway  of  12  miles  in  Britain  costs  30 
or  40,000Z.  but  it  will  last  20  years  ;  672 
horses  and  harness  would  cost  20,000J. 
renewable  every  four  years.  The  coke 
for  200  tons  for  24  hours,  would  be  6i 
tons,  and  assistance  about  ol,  but  the 
horses  would  cost  75Z.  for  keep. 

On  a  level  railroad,  the  force  of 
draught,  or  traction,  is  about  the  240th, 
i.  e.  1  cwt.  of  force  is  requisite  to  draw 
12  tons.  In  an  ascending  road,  this  force 
must  be  increased  by  the  ratio  of  the 
rise  to  the  length.  Thus,  a  rise  1  foot  in 
60  would  demand  a  60th  of  the  weight, 
or  12  tons  would  demand  4  cwt.  of  force 
more,  or  5  cwt.  One  foot  in  100  would 
require  2-4  more,  or  3'4  cwt.  to  draw  it. 
and  so  on.  This  difficulty  is  obviated 
by  a  horse- wheel  at  the  top  of  each  plane, 
or  by  dividing  the  load  at  bottom,  and 
re-uniting  at  lop.  A  station  engine,  or 
an  extra  engine,  requires  to  be  made 
ready.  But,  in  general,  an  engine  does 
not  travel  with  all  its  power,  so  that  in- 
clinations of  1  in  240  feet  may  be  sur- 
mounted by  enlarging  the  throttle  valves, 
so  as  to  double  its  own  power.  A  heavy 
mass,  rolling  the  contrary  way,  would 
obviously  give  the  requisite  force  ;  while 
the  pulling  it  up  again  would  be  conveni- 
ent in  descents.  Lardner  suggests  lifting 
stages,  on  the  principle  of  canal  locks. 

Perkins  showed,  that,  by  increasing 
the  strength  of  the  apparatus,  we  might 
use  steam,  so  excited  by  increased  mo- 
tion as  to  press  with  a  force  of  2000  lbs. 
to  the  square  inch. 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


591 


The  fire-tubes  are  now  increased  from 
100  to  150  of  1,  1-5,  and  2  inches  diame- 
ter, so  that  no  heat  is  lost,  and  the  water 
is  everywhere  in  contact  with  the  pipes 
filled  with  excited  air,  which,  in  all  cases, 
is  the  means  of  transmitting  the  motion 
of  fixed  oxygen  to  bodies  within  its 
ascending  curreut. 

For  security,  also,  the  steam  is  confin- 
ed within  plates,  so  that  their  reduced 
strength  is  a  constant  safety-valve. 

The  crank,  connected  with  the  wheels, 
makes  a  revolution  at  each  stroke  of  the 
piston  ;  hence,  the  velocity  is  governed 
by  the  rapid  generation  of  steam,  and 
this  is  as  the  heat.  If  the  wheels  are  5  feet 
or  16  round,  16  into  the  strokes  per  minute 
expresses  the  velocity  on  level  ground. 

STEAM  ENGINE.  The  first  actual 
working  steam  engine  of  which  there  is 
any  record,  was  invented  and  construct- 
ed by  Captain  Savery,  an  Englishman  ; 
to  whom  a  patent  was  granted  for  it,  in 
169S.  These  engines  were  employed  to 
raise  water  by  the  expansion  and  conden- 
sation of  steam,  and  were  only  pumps. 
The  steam  engine  received  great  im- 
provements from  the  hands  of  Newco- 
men,  Beighton,  Blakey,  and  others,  from 
1705  to  1710.  Still,  however,  it  was  im- 
perfect and  rude  in  its  construction,  and 
was  chiefly  applied  to  "the  draining  of 
mines,  or  the  raising  of  water.  The 
steam  engine  was  brought  to  its  present 
high  state  of  perfection,  by  the  celebrat- 
ed James  Watt,  about  the  year  1782. 
The  numerous  and  vital  improvements 
introduced  by  him,  both  in  the  combina- 
tion of  its  mechanism,  and  in  the  econo- 
my of  its  management,  have  rendered 
the  steam  engine  at  once  the  most  pow- 
erful, the  most  easily  applied  and  regu- 
lated, and,  generally  speahing,  the  least 
expensive  of  all  prime  movers,  for  im- 
pelling machinery  of  every  description. 
Steam  engines  vary  much  in  magnitude, 
form,  and  proportions,  as  well  as  in  the 
details  of  the  machinery  by  which  the 
power  of  the  steam  is  applied.  In  short, 
the  form  of  the  engine,  the  arrangement 
and  construction  of  its  parts,  its  power, 
&c,  depend  entirely  on  the  purpose  to 
which  it  is  to  be  applied,  and  may  be  in- 
definitely diversified.  The  form  of  the 
steam  engine  is  susceptible  of  an  endless 
variety,  according  to  the  purposes  to 
which  it  is  to  be  applied  ;  its  mechanical 
energy  is  usually  estimated  in  horse 
power,  (see  Horse  Power,)  and  is  propor- 
tioned to  the  pressure  of  the  steam,  the 
area  of  the  piston,  and  the  velocity  at 
which  it  moves.    The  stupendous  effects 


which  have  resulted  from  the  application 
of  the  power  of  steam  in  recent  times, 
are  striking  attestations  of  the  immense 
value  of  the  invention.  By  the  agency 
of  steam,  the  seas  are  now  navigated  in 
defiance  of  wind  and  tide ;  the  earth  is 
made  to  yield  up  in  lavish  abundance  its 
metals  and  minerals ;  vast  marshes  are 
drained,  and  land  before  barren  rendered 
fruitful ;  communities  are  brought  into 
closer  connection  with  communities  ; 
fresh  and  inexhaustible  sources  of  wealth 
and  comfort  are  elicited  ;  new  combina- 
tions of  human  industry  and  ingenuity 
are  brought  into  requisition  ;  knowledge 
is  widely  scattered  abroad ;  distance  is 
lessened  by  velocity  of  locomotion ;  and 
time  itself  becomes*  more  precious.  Thus 
by  infinitely  enlarging  the  sphere  of  use- 
ful action  to  whatsoever  was  useful  be- 
fore, and  by  diffusing  among  millions 
what  previously  was  attainable  only  by 
the  few,  this  agent  has  wrought  a  change 
of  aspect  in  kingdoms,  in  commerce, 
and  in  the  individual  relations  of  society, 
to  an  extent  so  wide,  and  in  a  time  so 
brief,  that  the  history  of  the  world  bears 
no  parallel  to  it  in  influence. 

The  following  is  a  description  of  the 
various  forms  of  engines  commonly  in 
use  : 

Double-acting  Condensing  Steam-En- 
gine. This  form  of  engine  is  that  which  is 
almost  invariably  used  as  a  moving  pow- 
er in  almost  all  manufactures.  It  consists 
of  a  cylinder  represented  in  section  atC, 
in  which  a  moveable  piston  P  is  driven 
upwards  and  downwards  by  the  force  of 
steam  supplied  by  a  boiler  placed  near 
the  engine. 

This  piston  gives  motion  to  a  work- 
ing beam  H  /,  which,  by  means  of  a 
heavy  bar  O,  called  a  connecting  rod, 
moves  nfly-wheel  and  crank,  from  which 
the  machinery  to  be  worked  directly  re- 
ceives its  motion.  Steam  is  supplied 
from  the  boiler  to  the  cylinder  by  the 
steam-pipe  S.  The  throttle-valve  T  in  that 
pipe,  near  the  cylinder,  is  regulated  by  a 
system  of  levers  connected  with  the 
governor  Q.  This  governor  is  an  appara- 
tus consisting  of  two  heavy  balls  attach- 
ed to  the  ends  of  rods  which  are  kept  re- 
volving on  a  vertical  shaft  by  a  cord  or 
band,  or  by  a  train  of  cogged  wheels  con- 
nected with  the  fly-wheel.  The  velocity 
with  which  the  balls  of  the  governor  re- 
volve is  therefore  always  proportional  to 
that  of  the.  fly-wheel,  and  of  the  machine- 
ry driven  by  it.  If,  by  reason  of  too  ra- 
Eid  a  supply  of  steam,  an  undue  speed 
e  imparted  to  the  fly-wheel,  the  balls 


592 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[STK 


are  whirled  round  with  a  corresponding 
velocity  ;  and  by  reason  of  their  centri- 
fugal force  they  recede  from  the  vertical 


spindle  round  which  they  turn,  and  act- 
ing thereby  on  the  system  of  levers 
which  connect  them  with  the  throttle- 
valve  T,  they  partially  close  the  latter, 
check  or  diminish  the  supply  of  steam 
to  the  cylinder,  and  moderate  the  veloci- 
ry  of  the  machine.  If,  on  the  other 
hand,  the  motion  of  the  engine  be  slower 
than  is  requisite,  owing  to  a  deficient 
supply  of  steam  through  S,  then  the  balls, 
not  being  sufficiently  affected  by  centri- 
fugal force,  fall  towards  the  vertical  spin- 
dle, and  acting  on  the  system  of  levers 
in  the  contrary  way,  they  turn  the  throt- 
tle-valve T  more  fully  open,  and  admit  a 
more  ample  supply  of  steam  to  the  cylin- 
der, so  as  to  increase  the  speed  of  the 
engine  to  a  requisite  limit. 

The  piston  P  is  accurately  fitted  to  the 
cylinder,  and  made  to  move  in  it  steam- 
tight  by  packing,  with  which  it  is  sur- 
rounded. This  piston  divides  the  cylin- 
der into  two  compartments,  between 
which  there  is  no  communication  by 
which  steam  or  any  other  elastic  fluid 
can  pass.  A  case  B  B'  placed  beside  the 
cylinder,  contains  the  valves  by  means  of 
which  the  steam  which  impels  the  piston 
is  admitted  and  withdrawn,  and  the  pis- 
ton commences  its  motion  in  each  direc- 
tion. The  upper  steam-box  B  is  divided 
into  three  compartments  by  two  valves  : 
above  the  upper  steam-valve  V  is  a  com- 
partment communicating  with  the  steam- 
pipe  S.    Below  the  exhausting  valve  E 


is  another  compartment  communicating 
with  a  pipe  called  the  eduction-pipe,  whfch 
leads  downwards  from  the  cylinder  to  a 
vessel  called  the  condenser,  which  we 
shall  presently  describe.  By  this  educ- 
tion pipe  the  steam  is  withdrawn  from 
the  cylinder  after  it  has  driven  the  pis- 
ton. By  the  valve  V  a  communication 
may  be  opened  or  closed  between  the 
boiler  and  the  top  of  the  cylinder,  so  as 
to  admit  or  intercept  the  supply  of  steam 
from  the  one  to  the  other.  By  the  valve 
E  a  communication  may  be  opened  or 
closed  between  the  top  of  the  cylinder 
and  the  condenser,  so  that  tho  steam  in 
the  top  of  the  cylinder  may  either  be  per- 
mitted to  escape  into  the  condenser  or 
confined  in  the  cylinder.  The  continua- 
tion S'  of  the  steam-pipe  leads  to  the 
lower  steam-box  B,  which,  like  the  upper, 
is  divided  into  three  compartments  by 
two  valves  V  and  E'.  The  upper  com- 
partment communicates  with  the  steam- 
pipe  S',  and  the  lower  with  the  eduction- 
pipe.  By  means  of  the  valve  V  steam 
may  be  admitted  from  the  steam-pipe  S' 
to  the  bottom  of  the  cylinder,  and  by 
means  of  the  valve  E'  this  steam  may  be 
permitted  to  escape  to  the  condenser. 

The  four  valves  V,  E,  V,  and  E',  are 
in  the  engine  represented  in  the  figure 
connected  by  a  system  of  levers  with  a 
single  handle  or  spanner  m,  which  being 
pressed  upwards  or  downwards  opens  and 
closes  the  valves  in  pairs.  Thus  when 
it  is  pressed  down,  the  levers  connected 
with  it  raise  the  upper  exhausting  valve 
E  and  the  lower  steam  valve  V',  and 
close  the  upper  steam  valve  V  and  the 
lower  exhausting  valve  E'.  On  the  other 
hand,  when  the  spanner  m  is  pressed  up 
it  opens  the  upper  steam  valve  V  and 
the  lower  exhausting  valve  E',  and  at  the 
same  time  closes  the  upper  exhausting 
valve  E  and  the  lower  steam  valve  V. 

Mr.  Piment  has  improved  the  mode  of 
condensing  the  steam  after  it  has  done 
its  duty  in  the  cylinder.  The  steam  on 
leaving  passes  into  tubes  surrounded  by 
water  intended  for  the  boiler,  which  con- 
denses it  quickly,  and  is  itself  warmed. 
One  great  advantage  is  the  great  purity 
of  the  water  so  obtained  thereby  pre- 
venting incrustation,  and  the  water  itself 
being  heated  up  to  95°,  there  is  a  saving 
of  fuel.    It  is  now  extensively  used. 

Perkins's  High-Pressure  and  Safety- 
Engine  is  made  applicable  to  all  purposes 
of  steam  navigation,  and  consists  of  a 
steam-pipe  from  the  generators,  convey- 
ing the  steam  to  the  admission-valve, 
lying  horizontally  at  tho  back   of  tho 


VERTICAL  STEAM  ENGINE — FOR  MANUFACTURING   PURPOSES,      p.  593. 


ste] 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


593 


cylinder,  from  whence  it  acts  on  the  un- 
derside of  the  piston  at  a  pressure  of 
2000  lbs.  on  the  inch.  The  cylinder  is 
about  a  15-horse-power  ;  the  piston  only 
six  inches  in  diameter  ;  and  the  length 
of  stroke  only  20  inches. 

Palmer's  apparatus,  as  well  as  Brun- 
ton's,  consumes  the  smoke,  or  supplies 
sufficient  air  for  the  purpose,  either  by 
condensation  or  exhaustion,  turning  from 
right  to  left  or  left  to  right. 

By  placing  vane-wheels  within  the 
chimney  of  the  boiler  of  a  small  steam- 
engine,  the  smoke  and  hot  air  is  return- 
ed" through  the  fire  and  passed  down- 
wards, in  a  current,  towards  the  ground. 
Sometimes  an  air-pump  has  been  used 
instead  of  a  fan,  and  no  chimney  is  re- 
quisite ;  hence  steam-carriages  emit  no 
smoke. 

Non-condensing  Steam- Engines.  The 
form  and  structure  of  non-condensing 
engines  differ  in  nothing  from  that  of 
double-acting  condensing  engines,  except 
in  the  absence  of  the  condensing  appara- 
tus ;  that  is  to  say,  the  condenser,  the  air- 
pump,  and  the  cold  water  and  hot  water 
pumps.  The  steam,  after  it  has  impelled 
the  piston,  instead  of  being  conducted 
to  a  cold  vessel  to  be  condensed,  is  sim- 
ply allowed  to  escape  into  the  atmosphere, 
and  is  commonly  ejected  into  the  chim- 
ney of  the  furnace. 

The  operation  of  such  a  machine  is  ex- 
tremely simple.  The  valves  by  which 
the  steam  is  admitted  to,  and  allowed  to 
escape  from  the  cylinder,  are  exactly  simi- 
lar to  those  of  the  double  acting  engine. 
In  the  down  stroke  of  the  piston,  the  up- 
per steam  valve  being  open,  admits  steam 
from  the  boiler  above  the  piston,  and  the 
lower  exhausting  valve  allows  the  steam 
below  to  escape  through  a  tube  which 
leads  to  the  chimney,  up  which  it  rushes. 
In  the  up  stroke,  the  lower  steam  valve 
being  open  admits  steam  from  the  boiler 
below  the  piston,  and  the  upper  exhaust- 
ing valve  being  open  allows  the  steam 
above  the  piston  to  escape  to  the  chim- 
ney. 

It  is  evident,  in  such  a  machine,  that 
the  piston  is  always  resisted  by  the  pres- 
sure of  the  steam  escaping  to  the  chim- 
ney. As  such  escape  cannot  be  effected 
except  by  steam  of  greater  pressure  than 
that  of  the  atmosphere,  it  follows  that 
the  piston  is  always  resisted  by  a  force 
somewhat  greater  than  the  atmospheric 
pressure.  The  steam  which  urges  the 
piston  is,  therefore,  only  effective  by  the 
excess  of  its  pressure  above  that  of  the 
escaping  vapor,  which  may  be  taken  at 


about  16  lbs.  per  inch,  but  which  varies 
in  different  engines. 

As  the  steam  used  in  non-condensing 
engines  must  of  necessity  have  a  pres- 
sure considerably  exceeding  that  of  the 
atmosphere,  such  machines  have  been 
generally  called  high-pressure  engines; 
while  those  which  condense  the  steam 
have  been,  on  the  other  hand,  called 
low-pressure  engines.  These  terms  are 
not,  however,  correctly  expressive  of  the 
nature  of  these  engines  respectively. 
Since  the  pumps  of  the  non-condensing 
engine  are  dispensed  with  in  this,  the 
beam  may  be  so  likewise,  and  a  still 
further  simplification  results  from  an 
oscillating  movement  given  to  the  cylin- 
der ;  such  are  termed  vibrating  engines, 
and  are  successfully  used  where  space  is 
limited  as  in  marine  engines.  Many  en- 
gines in  which  condensation  is  used, 
especially  those  in  which  the  expansive 
principle  is  applied  with  much  effect,  are 
worked  with  steam  of  a  high  pressure, 
not  unfrequently  with  a  pressure  amount- 
ing to  from  two  to  three  atmospheres. 
It  is,  therefore,  not  correct  to  call  such 
machines  low  pressure  engines.  It  is, 
however,  true  that  engines  worked  with- 
out condensation  must,  of  necessity,  be 
worked  by  steam  of  a  pressure  which  is 
generally  called  high  pressure. 

An  improvement  in  oscillating  engines 
has  been  introduced,  which  consists  in 
the  substitution  of  a  circular  valve  for 
the  ordinary  slide  valve,  thus  dispensing 
with  eccentric  guides,  which  renders  the 
engine  less  complicated,  more  easily 
managed,  as  one  lever  suffices  for  use. 
It  is  especially  applicable  to  small  river 
boats. 

All  locomotive  engines,  without  excep- 
tion, used  on  railways  or  common  roads, 
are  high-pressure  non-condensing  en- 
gines. [See  Locomotive  Engine,  and 
Steam  Carriage.) 

High-pressure  non- condensing  engines 
are  almost  universally  used  for  inland 
navigation  at  the  West  and  South. 

The  accompanying  engraving  repre- 
sents a  vertical  high-pressure  engine,  not 
occupying  much  space,  and  adapted  for 
printing  or  manufacturing  purposes. 

Rotary  Steam  Engine.— This  term  is 
sometimes  applied  to  the  double-acting 
engine  working  a  crank  and  fly- wheel", 
as  distinguishing1  it  from  the  single-act- 
ing engine  used  for  pumping.  But  it  is 
more  properly  applied  to  an  engine  in 
which  a  motion  of  rotation  is  produced 
immediately  by  the  action  of  steam, 
without  the  intervention  of  such  raecha- 


594 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[STK 


nism  as  the  working  beam,  crank,  and 
fly-wheel.  This  is  usually  effected  by  a 
piston,  which,  instead  of  moving  longi- 
tudinally in  the  cylinder,  revolves  with- 
in the  cylinder  on  an  axis  which  coin- 
cides with  the  geometrical  axis  of  the 
cylinder  itself.  The  mechanism  is  so 
contrived  that  this  piston  shall  revolve 
in  steam-tight  contact  with  the  sides  and 
ends  of  the  cylinder;  and  that  while 
steam  from  the  boiler  constantly  presses 
it  on  one  side,  the  steam  on  the  other 
side  shall  continually  escape  to  the  con- 
denser, if  it  be  a  condensing  engine,  or 
to  the  chimney,  if  it  be  anon-condensing 
engine.  The  various  contrivances  for 
rotary  engines  which  have  been  suggest- 
ed differ  one  from  the  other  only  in  the 
mechanical  expedients  by  which  these 
ends  are  attained.  Such  machines  are 
very  numerous  and  various. 

A  cubic  inch  of  water  becomes  very 
nearly  a  cubic  foot  as  vapor,  or  steam  of 
the  first  degree,  exactly  1689,  and  there 
are  1728  cubic  inches  in  a  foot.  When 
water  is  at  212,  it  requires  6  times  the 
heat  to  vaporize  a  foot  that  it  did  to  raise 
a  foot  from  ice  to  212°  ;  and  if  1  foot  of 
water,  as  steam,  be  mixed  with  6  of  wa- 
ter at  82,  it  becomes  7  at  212,  showing 
that  there  is  6  times  the  motion  in  steam 
that  there  is  in  water,  yet,  as  density  is 
inversely  as  bulk,  a  thermometer  in  such 
steam  still  stands  at  212°. 

the  power  of  every  stroke  of  an  engine 
is  easily  estimated.  Square  the  inside 
diameter  of  the  piston  in  inches,  and 
multiply  by  0*7854.  Or,  square  the  in- 
side circumference  in  inches,  and  multi- 
ply by  0*07958.  Then,  with  an  atmos- 
pheric power,  multiply  by  15,  and  allow 
for  friction  and  loss  of  power  a  fourth  or 
fifth.  With  a  real  steam  power  or  high- 
pressure  engine  multiply  by  the  number 
indicated  by  heat  less  'the  atmospheric 
pressure,  as  50,  200,  or  300,  as  it  may  be, 
and  allow  a  fifth  friction. 

Effect,  or  work,  is  as  the  number  and 
length  of  strokes  per  minute,  since  the 
power  is  the  multiple  of  the  first  force  by 
the  velocity. 

Eight  square  feet  of  the  surface  of  the 
boiler  must  be  acted  on  by  the  fire,  to 
convert  a  cubic  foot  of  water  into  steam 
in  an  hour,  and  then  it  becomes  1728 
cubic  feet ;  that  is,  from  1  foot  each  way 
to  12  feet  in  each  dimension.  The  num- 
ber of  atoms  is  the  fame,  and  they  mere- 
ly fill  a  larger  space  by  their  combined 
p.  itions. 

The  power  is  equal  to  the  expansion  or 

June.    At  212.  the  steam  to  the  water 


is  as  1728  to  1,  which  give  a  force  of 
15  lbs.  to  the  square  inch  ;  but,  at  227i° 
to  the  volume  is  5  times  greater,  or  9000 
to  1 ;  at  250s,  is  15  times  greater,  27,000 
to  1  ;  and,  at  282°,  is  40  times  greater, 
or  72,000  steam  to  1  of  water,   with  a 

Sower  of  55  lbs.  to  the  square  inch, 
irunton  says  it  may  be  expanded  to  400 
times  its  bulk  at  212°.  Its  force  depends 
on  the  power  and  continuity  of  compres- 
sion, or  reaction,  and  the  vast  increase  is 
an  accelerated  power. 

Expansive  Engine. — As  the  operation 
of  the  steam  engine  has  been  explained, 
the  power  which  moves  the  piston  is  the 
immediate  force  with  which  vapor  is  pro- 
duced in  the  boiler.  Each  quantity  of 
water  which  is  successively  evaporated 
obtains  the  space  requisite  for  it  in  the 
form  of  steam,  by  pressing  towards  the 
cylinder  an  equal  quantity  of  steam  pre- 
viously contained  in  the  boiler  ;  and  it  is 
the  force  with  which  the  steam  is  thus 
pressed  forward  that  impels  the  piston. 
Great  additional  mechanical  power  will 
be  obtained  from  the  steam,  if,  besides 
this  moving  power  which  results  from 
immediate  evaporation,  the  expansive 
power  of  the  steam  separated  from  the 
water  be  used.  This  is  accomplished  by 
closing  the  valve  through  which  steam 
flows  from  the  boiler  to  the  cylinder  be- 
fore the  piston  has  completed  its  stroke. 
Thus,  let  us  suppose  that  when  the  pis- 
ton has  advanced  through  half  its  stroke 
the  steam  valve  be  closed,  the  steam 
which  is  then  acting  upon  the  piston  will 
still  urge  it  forward ;  but  as  the  piston 
advances,  this  steam,  assuming  a  propor- 
tionally augmented  volume,  will  acquire 
a  gradually  diminished  pressure,  so  that 
through  the  remaining  half  of  the  stroke 
the  piston  will  be  urged  by  a  pressure 
progressively  decreasing,  and  at  the  ter- 
mination of  the  stroke,  it  will  be  a  little 
less  than  half  the  force  with  which  the 
piston  was  impelled  while  the  steam 
valve  was  opened. 

Since  the  force  of  the  steam,  from  the 
moment  the  steam  valve  is  closed,  is  thus 
continually  diminished,  its  moving  power 
might  be  so  much  attenuated  that  it 
would  be  incapable  of  overcoming  the 
resistance  so  as  to  complete  the  stroke  ; 
this  would  happen  if  the  steam  were  cut 
off  when  only  a  small  fraction  of  the 
stroke  has  been  made,  unless  the  pres- 
sure of  the  steam  while  the  valve  is  open 
exceeds  the  resistance  in  a  proportionate 
degree.  It  is  for  this  reason  that  the 
expansive  principle  cannot  be  brought 
into  operation  to  any  considerable  extent, 


steJ 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


595 


unless  steam  be  used  of  a  greater  pres- 
sure than  is  commonly  adopted  in  low- 
pressure  engines.  It  is  also  apparent 
that  with  an  equal  volume  of  cylinder 
greater  length  of  stroke  should  be  given 
when  the  expansive  principle  is  used. 

The  mechanism  by  which  the  expan- 
sive principle  is  brought  into  practical 
operation,  consists  merely  in  the  adapta- 
tion of  valves  or  slides,  which  shall  stop 
the  admission  of  steam  when  the  required 
fraction  of  the  stroke  has  been  made  by 
the  piston,  but  which  shall  leave  the 
communication  with  the  condenser  open 
till  the  stroke  is  completed.  If  separate 
valves  be  used,  this  is  accomplished  by 
adapting  the  pins  or  other  mechanism 
by  which  they  are  worked  to  open  and 
close  them,  independently  of  each  other, 
at  the  proper  times.  If  slides  be  used, 
it  is  effected  by  regulating  the  form  and 
aperture  of  the  slide,  so  as  to  cover  and 
uncover  the  passages  to  the  cylinder  at 
the  proper  times.  Each  species  of  valve, 
and  each  form  of  slide  or  cock,  has  its 
own  peculiar  provisions  for  accomplish- 
ing this. 

Single-acting  Steam  Engine.  —  When 
the  steam  engine  is  applied  to  the  pur- 

Sose  of  pumping  water,  which  in  the 
rst  periods  of  its  invention  was  its  only 
practical  application,  the  force  which  it 
exerts  is  only  required  in  raising  the 
pump  rods  with  their  load  of  water, 
their  own  weight  being  more  than  suffi- 
cient for  their  descent.  As  the  pump 
rods  are  attached  to  the  working  end  of 
the  beam,  the  force  of  the  steam  is  only 
required  to  draw  up  that  end,  and,  there- 
fore, to  draw  down  the  end  at  which  the 
steam  piston  is  attached ;  the  steam,  there- 
fore, being  only  required  to  press  the  pis- 
ton downwards,  it  is  not  admitted  from  the 
boiler  above  it,  as  in  the  engine  already 
described,  which  for  distinction  is  called 
the  double-acting  engine.  During  the 
down  stroke  of  the  single-acting  engine 
the  performance  of  the  machine  is  pre- 
cisely similar  to  that  already  described  ; 
steam  is  admitted  through  the  upper 
steam  valve  above  the  piston,  while  the 
space  in  the  cylinder  below  the  piston  is 
kept  in  free  communication  with  the  con- 
denser by  keeping  the  lower  exhausting 
valve  open.  The  operation,  therefore, 
of  the  upper  steam  valve,  and  the  lower 
exhausting  valve,  is  precisely  the  same 
as  in  the  double-acting  engine.  When 
the  piston  has  reached  the  bottom  of  the 
cylinder,  the  two  former  valves  being 
closed,  a  valve  callod  the  equilibrium 
valve  is  opened,  by  which  a  free  commu- 


nication is  made  between  the  top  and  the 
bottom  of  the  cylinder  :  by  this  means 
the  steam  which  fills  the  upper  part  of 
the  cylinder,  being  allowed  to  flow  equally 
to  the  lower  part,  will  press  with  the 
same  force  on  both  sides  of  the  piston,  and 
will,  therefore,  have  no  tendency  whatever 
to  move  it.  Under  these  circumstances, 
the  preponderating  weight  of  the  pump 
rods  suspended  from  the  other  end  of 
the  beam  will  draw  the  piston  to  the  top 
of  the  cylinder :  while  it  is  ascending 
the  steam  which  was  above  will  pass 
through  the  equilibrium  valve  below  it, 
and  when  the  piston  has  reached  the  top 
of  the  cylinder,  the  cylinder  under  the 
piston  will  be  filled  with  the  same  steam 
which  previously  had  driven  the  piston 
down. 

Upon  the  occurrence  of  the  next  down 
stroke,  the  equilibrium  valve  is  closed, 
and  the  upper  steam  valve  and  lower  ex- 
hausting valve  are  opened ;  the  steam 
pressure  acts  above  the  piston,  and  a  va- 
cuum is  produced  below  it,  and  the  pis- 
ton descends  as  before. 

Atmospheric  Engine. — The  engine  so 
called  was  the  first  form  of  steam  engine 
which  was  ever  brought  into  extensive 
and  durable  practical  application,  and  in 
districts  where  fuel  is  cheap  and  abun- 
dant the  simplicity  of  its  structure  still 
keeps  it  in  partial  use.  Steam,  in  the 
atmospheric  engine,  is  only  used  as  an 
agent  for  the  production  of  a  vacuum,  in 
order  to  give  effect  to  the  atmospheric 
pressure.  It  was  originally  only  used  for 
pumping  water. 

The  atmospheric  engine,  which  is  only 
applied  to  pumping,  consists  of  a  cylin- 
der open  at  the  top,  having  a  piston 
which  moves  in  it  air-tight  and  steam- 
tight.  The  piston  is  thus  maintained  by 
being  lubricated  by  oil  or  melted  tallow 
poured  above  it.  Supposing  the  piston 
to  be  at  the  bottom  of  the  cylinder,  steam 
is  admitted  from  the  boiler  by  a  proper 
valve.  This  steam,  having  a  pressure 
not  much  exceeding  that  of  the  atmos- 
phere, will  balance  the  pressure  of  the 
atmosphere  above  the  piston,  and  will  be 
sufficient,  also,  to  overcome  the  friction 
of  the  piston  with  the  cylinder.  Under 
such  circumstances,  the  preponderating 
weight  of  the  pump  rod  at  the  other  end 
of  the  beam  draws  the  piston  to  the  top 
of  the  cylinder,  in  the  same  manner  as 
the  piston  is  drawn  up  in  the  single-act- 
ing steam  engine  already  described.  The 
piston  being  thus  suspended  at  the  top 
of  the  cylinder,  the  valve  admitting 
steam   from   the   boiler    is    closed,   and 


596 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[STE 


another  valve  or  cock  is  opened  by  which 
a  jet  of  cold  water  is  thrown  into  the  cy- 
linder. This  immediately  condenses  the 
steam,  and  leaves  a  vacuum  under  the 
piston.  The  atmospheric  pressure  above 
it  consequently  takes  effect,  and,  forcing 
the  piston  to  the  bottom  of  the  cylinder, 
draws  the  pump  rods,  with  their  load  of 
water,  up.  "When  the  piston  arrives  at 
the  bottom  of  the  cylinder,  the  cock  ad- 
mitting the  jet  of  cold  water  is  closed, 
and  another  is  opened,  by  which  the 
warm  water  formed  by  the  mixture  of 
the  condensed  steam  with  the  cold  water 
of  the  jet  is  discharged  into  a  reservoir 
from  which  the  boiler  of  the  engine  is 
fed.  The  steam  is  then  again  admitted 
from  the  boiler,  the  piston  ascends,  and 
so  the  process  is  contmued. 

The  cocks  or  valves  above  mentioned 
are  opened  and  closed  at  the  proper  times 
by  means  of  a  rod  or  beam,  called  the 
plug  frame,  attached  to  the  working 
beam,  which  is  placed  and  which  is  moved 
in  a  manner  similar  to  the  rod  of  the  air- 
pump  in  the  steam  engines  already  de- 
scribed. 

STEAM  NAVIGATION.  The  art 
of  applying  the  power  of  steam  to  the 
propulsion  of  boats  and  vessels  in  general, 
as  well  for  inland  communication  by  riv- 
ers and  lakes,  as  for  the  general  purposes 
cf  national  commerce  on  the  seas  and 
oceans  by  which  the  various  parts  of  the 
globe  are  separated. 

To  save  space,  marine  boilers  are  con- 
structed so  as  to  produce,  within  the 
smallest  possible  dimensions,  the  neces- 
sary quantity  of  steam.  With  this  view, 
a  more  extensive  surface  in  proportion  to 
the  capacity  of  the  boiler  is  exposed  to 
the  fire.  The  flues  by  which  the  flame 
and  heated  air  are  conducted  to  the  chim- 
ney are  so  constructed  that  the  heat  shall 
act  upon  the  water  on  every  side  in  thin 
oblong  shells  or  plates.  This  is  accom- 
plished by  constructing  them  so  as  to  tra- 
verse the  boiler  backwards  and  forwards 
several  times  before  they  issue  into  the 
chimney.  The  bottom  of  the  boiler  is 
not,  therefore,  one  uniform  flat  or  arched 
surface,  as  in  land  boilers  ;  but  is  divided 
by  a  number  of  plates  placed  in  a  vertical 
position  side  by  side,  iiaving  spaces  be- 
tween them  alternately  appropriated  to 
the  water  to  be  heated  and  the  air  from 
the  fire.  This  division  is,  in  some  boil- 
ers, not  only  made  in  the  bottom  on  a 
level  nearlv  with  the  furnace,  but  another 
stratum  or"  similar  flues  and  water  spaces 
is  constructed  above  the  level  of  the  fur- 
nace ;  so  that  the  heated  air  first  traverses 


the  lower  stratum  of  flues,  and  afterwards, 
being  conducted  upwards,  traverses  the 
upper  stratum  before  it  issues  into  the 
chimneys. 

In  steam  vessels,  instead  of  effecting 
the  necessary  evaporation  by  a  single 
boiler,  it  is  usual  to  provide  two,  three, 
four  or  more,  independent  boilers,  accord- 
ing to  the  magnitude  of  the  vessel  and 
the  power  of  her  engines.  By  this  means, 
when  at  sea,  the  engines  may  be  worked 
by  some  of  the  boilers  while  others  are 
being  cleaned  "or  repaired. 

The  manner  in  which  the  steam  engine 
is  rendered  an  instrument  for  the  propul- 
sion of  vessels  must,  in  its  general  fea- 
tures, be  so  familiar  to  every  one  as  to  re- 
quire but  short  explanation.  A  shaft  is 
carried  across  the  vessel,  being  continued 
on  either  side  beyond  the  timbers;  to 
the  extremities  of  this  shaft  on  the  out- 
side of  the  vessel,  are  attached  a  pair  of 
wheels,  constructed  like  under-shot  wa- 
ter wheels,  having  fixed  upon  their  rims  a 
number  of  flat  boards  called  paddle  boards. 
As  the  wheels  revolve  these  paddle  boards 
strike  the  water,  driving  it  m  a  direction 
contrary  to  that  in  which  it  is  intended 
the  vessel  shall  be  propelled.  The  mov- 
ing force  imparted  to  the  water  thus 
driven  backwards  by  reaction  on  the  ves- 
sel propels  it.  On  the  paddle  shaft  are 
constructed  two  cranks  or  winches,  placed 
at  right  angles  one  to  the  other,  so  that 
whenever  one  of  them  is  thrown  into  the 
highest  or  lowest  position,  the  other  is 
horizontal.  These  cranks  are  worked  by 
strong  iron  rods  called  connecting  rods, 
which  are  themselves  either  driven  di- 
rectly by  the  pistons  of  two  t.team  en- 
gines, or  are  worked  by  beams  or  levers; 
thus  the  medium  of  working  becomes 
similar  to  those  used  in  the  ordinary 
land  engines.  (See  Steam  Engine.)  The 
two  cranks  being  placed  at  right  angles, 
it  follows  that  when  one  piston  is  at  the 
top  or  bottom  of  its  stroke,  and  the  crank 
driven  by  it  in  the  highest  or  lowest  po- 
sition, the  other  will  be  at  the  middle  of 
its  stroke,  and  the  crank  driven  by  it  will 
be  in  the  horizontal  position.  One  of  the 
pistons  is  therefore  always  in  a  position 
to  produce  the  most  advantageous  effect 
on  the  crank  at  the  moment  that  the  other 
piston  loses  all  power  over  the  crank 
driven  by  it ;  and  in  the  same  manner  it 
may  be  seen  that  while  the  power  of  one 
piston  is  augmented  from  zero  to  its 
greatest  effect,  the  power  of  the  other  is 
decreasing  from  its  greatest  effect  to  zero. 
Thus  the  combined  action  of  the  two  pis- 
tons is  nearly  uniform  to  its  efficiency. 


8TE] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


If  one  engine  only  were  used,  the  motion 
of  the  wheels  would  be  unequal,  being 
most  rapid  when  the  piston  is  at  the  mid- 
dle of  the  stroke  and  slowest  at  the  ex- 
tremities. 

The  steam  engines  used  for  navigation 
may  be  either  condensing  engines  or  non- 
condensing  engines.  If  the  latter  are 
used,  steam  must  be  used  haying  a  pres- 
sure above  the  atmosphere  of  from  15  to 
20  lbs.  per  square  inch.  Boilers  in  which 
steam  is  produced  under  this  pressure 
are  considered  in  Europe  so  unsafe,  that 
there  condensing  engines  with  low  pres- 
sure boilers  are  almost  universally  used 
for  navigation.  On  this  continent,  how- 
ever, high-pressure  boilers  with  non-con- 
densing engines  are  generally  used. 

The  arrangement  of  the  parts  of  marine 
engines  is  different  in  several  respects 
from  land  engines.  Steam  vessels  being 
generally  employed  to  navigate  the  open 
seas,  aiid  being,  therefore,  subject  to  the 
vicissitudes  of  tempestuous  weather,  the 
machinery  must  be  protected  by  being 
placed  below  the  deck.  The  space  allot- 
ted to  it  being  thus  limited,  great  compact- 
ness is  necessary.  The  paddle  shaft  be- 
ing very  little  below  the  deck,  the  work- 
ing beam  and  connecting  rod  could  not 
be  placed  above  it.  Two  beams  are  used 
— one  placed  on  either  side  of  the  cy- 
linder. These  have  a  common  centre 
of  oscillation,  which  is  placed  near  the 
bed  of  the  engine.  At  the  one  end, 
links  from  the  cross-head  of  the  piston  are 
connected  with  the  beams  ;  at  the  other, 
through  the  intervention  of  a  cross-tail, 
the  connecting-rod  is  attached,  thus  com- 
pleting the  connection  with  the  crank. 

Where  sea  water  is  used  in  the  boilers, 
as  the  water  evaporates  the  salts  are  de- 
posited in  an  insoluble  form  on  the  inner 
surface  of  the  boiler,  forming  a  crust  diffi- 
cult to  remove,  and  causing  loss  by  pre- 
venting the  heat  reaching  the  water  in 
the  boiler  until  the  metal  is  heated  very 
hot,  when  explosions  are  liable  to  occur. 
Dr.  Davy,  on  the  best  method  of  pre- 
venting the  incrustation  in  the  boilers  of 
steam  vessels,  says,  it  is  principally  crys- 
talline in  structure,  composed  chiefly  of 
sulphate  of  lime.  To  prevent  the  deposi- 
tion of  the  incrusting  matter,  the  addi- 
tion of  muriate  of  ammonia  and  sulphate 
of  ammonia  have  been  employed,  but 
without  success.  The  introduction  of  a 
certain  quantity  of  sawdust  or  tallow,  or 
a  mixture  of  tallow  and  plumbago,  to 
prevent  close  adhesion  and  the  more  easy 
separation  of  the  incrusting  matter  by 
percussion,  using  a  chisel  hammer,  or  by 


contraction  and  unequal  expansion  by 
means  of  flame  kindled  with  oakum  after 
emptying  the  boiler  and  drying  it,  has 
been  attempted,  with  partial  success. 
The  best  method  is  that  ot  "  blowing  off," 
that  is,  discharging  by  an  inferior  stop- 
cock a  certain  quantity  of  the  concentrat- 
ed water  by  the  pressure  of  steam,  after 
the  admission  above  of  an  equivalent 
quantity  of  sea  water  of  ordinary  density. 
A  certain  preventive  would  be  the  sub- 
stitution or  distilled  or  rain  water  in  the 
boiler  for  sea  water.  But  in  sea  steam- 
ers, in  which  sea  water  is  used,  or  any 
water  containing  sulphate  of  lime,  the 
prevention  of  deposition  may  be  effected 
by  keeping  the  water  at  that  degree  of  di- 
lution at  which  the  sulphate  of  lime  is 
not  separated  from  the  water  in  which  it 
is  dissolved.  Sulphate  of  lime  is  hardly 
less  soluble  in  water  saturated  with  com- 
mon salt  than  in  perfectly  fresh  water. 
The  great  object  in  sea  steamers  is  to 
economize  the  escape  of  water  in  the  form 
of  steam,  and  thereby  heat  and  fuel,  also 
to  use  fresh  water  as  much  as  possible, 
and  to  avoid  using  sea  water  near  coasts 
and  parts  of  seas  where  sulphate  of  lime 
is  most  abundant. 

The  method  by  which  the  water  in  the 
boiler  is  prevented  from  being  over  salted, 
has  been  usually  to  discharge  into  the  sea  a 
certain  quantity  of  over  salted  water  (called 
brine),  and  to  supply  its  place  by  sea  wa- 
ter introduced  through  the  condenser,  and 
which,  being  mixed  with  the  condensed 
steam,  is  rather  less  salted  than  ordinary 
sea  water.  To  effect  this,  cocks,  called 
blow-off  cocks,  are  placed  in  the  lower 
part  o'f  the  boiler  where  the  brine  collects. 
The  pressure  of  the  steam  is  sufficient  to 
force  the  lower  strata  of  water  out  through 
these  cocks  when  they  are  open,  and 
this  process  is  called  blowing  out.  It  is, 
or  ought  to  be,  practised  at  such  intervals 
as  will  prevent  the  water  from  becoming 
over  patted. 

The  improper  observance  of  this  pro- 
cess is  attended  with  injurious  effects  at 
sea.  If  too  much  water  be  blown  out,  a 
proportionate  loss  of  heat  and  waste  of 
fuel  is  incurred.  If  insufficient  water  be 
blown  out,  incrustation  takes  place,  and 
its  injurious  consequences  ensue. 

Where  there  is  plenty  of  boiler-room 
no  boiler  is  like  the  long  cylinder  one 
with  return  flues.  It  is  the  safest  and 
best.  For  compactness  the  tubular  boil- 
er is  best,  but  then  it  needs  pure  water, 
for  it  has  so  many  joints  that  it  is  difficult 
to  prevent  leakage,  owing  to  the  expan- 
sion and  contraction;  incrustations  are 


598 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[STE 


also  sure  to  act  injuriously  towards  the 
end  of  a  tedious  sea  voyage.  Tubular 
boilers  are  peculiarly  liable  to  priming, 
and  great  danger  arises  from  this  cause. 
A  scale  of  about  l-16th  of  an  inch  is  form- 
ed in  the  interior  of  the  boilers  of  our 
ocean  steamers,  during  one  passage  be- 
tween New- York  and  Liverpool,  and  the 
evil  of  this  is  far  greater  in  tubular  than 
it  can  be  in  any  other  boiler.  It  is  very 
difficult  to  maintain  the  feed  of  tubular 
boilers  at  a  uniform  height,  owing  to 
the  smaller  quantity  of  water  in  them 
than  in  the  common  boilers;  the  only 
remedy  is  carefulness  on  the  part  of  the 
engineers — when  this  is  wanting,  then 
there  is  danger. 

As  the  voyages  accomplished  by  steam 
vessels  have  increased  in  length,  the  eco- 
nomy of  fuel  in  working  them  has  be- 
come a  subieet  of  vastly  augmented  im- 
portance. So  long  as  steam  navigation 
was  confined  to  river  or  channel  trans- 
port, or  to  coasting  voyages,  the  speed  of 
the  vessel  was  a  paramount  consideration, 
at  whatever  expenditure  of  fuel  it  might 
be  obtained  ;  but  since  steam  navigation 
has  been  extended  to  ocean  voyages, 
where  coals  must  be  transported  sufficient 
to  keep  the  engine  in  operation  for  a  long 
period  of  time  without  a  fresh  relay, 
greater  attention  has  been  bestowed  on 
economizing:  it.  Since  the  resistance  of 
a  steam  vessel  to  the  moving  power  pro- 
duced by  the  action  of  the  paddle  wheels 
varies  with  the  state  of  the  weather,  the 
consumption  of  steam  in  the  cylinders 
must  undergo  a  corresponding  variation  ; 
and  if  the  production  of  steam  in  the 
boilers  be  not  proportioned  to  this,  the 
engines  will  either  work  with  less  effi- 
ciency than  they  might  do  under  the  ac- 
tual circumstances  of  the  weather,  or 
more  steam  will  be  produced  than  the 
cylinders  can  consume,  and  the  surplus 
will  be  discharged  to  waste  through  the 
safety  valves.  The  fireman  of  a  marine  en- 
gine must,  therefore,  iii  a  certain  degree, 
discharge  the  functions  of  a  self-regulating 
furnace,  rendering  the  force  of  the  fire  al- 
ways proportionate  to  the  wants  of  the 
engine.  None  but  the  most  iudustrious 
and  skilful  stokers  can  be  expected  to  ac- 
complish this. 

Until  within  a  few  years  of  the  present 
time  the  heat  radiated  from  every  part  of 
the  surface  of  the  boiler  was  allowed  to 
go  *,*  waste,  and  to  produce  injurious 
effects  on  those  parts  of  the  vessel  to 
which  it  was  transmitted.  This  evil  has 
been  lately  removed  by  coating  the  exte- 
rior of  the  boilers  with  felt  prepared  for 


the  purpose,  by  which  the  escape  of  heat 
from  the  surface  of  the  boiler  is  very 
nearly  if  not  altogether  prevented.  This 
felt  is  attached  to  the  plates  of  the  boiler 
by  a  thick  covering  of  white  and  red  lead. 
The  method  by  which  the  greatest 
amount  of  practical  effect  can  be  obtained 
from  a  given  quantity  of  fuel  must  mainly 
depend  on  the  extensive  application  of 
the  expansive  principle.  (See  Steam, 
Steam  Engtne).  The  difficulty  of  the  ap- 
plication of  this  principle  in  marine  en- 
gines has  arisen  from  the  objections  en- 
tertained in  Europe  against  the  use  of 
steam  of  high  pressure  under  the  circum- 
stances in  which  an  engine  must  be  work- 
ed at  sea.  This  objection  is  not  felt  in 
this  country,  where  all  the  river  steamers 
act  on  the  expansive  principle.  To  apply 
the  expansive  principle  with  great  effect, 
it  is  necessary  that  the  moving  power  at 
the  commencement  of  the  stroke  shall 
considerably  exceed  the  resistance,  its 
force  being  gradually  attenuated  till  the 
completion  of  the  stroke,  when  it  will 
finally  become  less  than  the  resistance. 
This  condition  may  be  fulfilled  without 
resorting  to  steam  of  high  pressure,  if  a 
sufficient  quantity  of  piston  surface  be 
used.  This  method  of  rendering  the  ex- 
pansive principle  available  for  navigation 
and  compatible  with  low-pressure  steam 
has  recently  been  modified  in  England 
by  Messrs.  Maudsley  and  Field.  Their 
improvement  consists  in  adapting  two 
steam  cylinders  in  one  engine  to  work  a 
single  crank,  both  pistons  ascending  and 
descending  together,  the  piston  rods  be- 
ing both  attached  to  the  same  horizontal 
cross-head  moving  in  guides. 

About  the  year  1833,  Mr.  Field  propos- 
ed the  split  paddle,  which  is  now  coming 
into  very  extensive  use.  In  this  wheel 
each  paddle  board  is  divided  into  two  or 
more  narrow  slips  arranged  one  behind 
the  other,  like  the  laths  of  a  Venetian 
blind  or  the  steps  of  a  step-ladder.  These 
wheels  are  as  efficient  in  propelling  when 
at  the  lowest  point  as  the  common  paddle 
boards  ;  and  when  they  emerge  the  wa- 
ter escapes  simultaneously  from  each  nar- 
row board,  and  is  not  thrown  up,  as  is 
the  case  with  the  common  paddles. 

The  construction  of  a  good  and  efficient 
paddle  is  still  a  desideratum. 

The  problem  of  the  application  of  steam 
power  to  water  transport  presented  itself 
in  the  United  States  under  conditions 
very  different  from  those  under  which  il 
offered  itself  in  Europe,  and  its  solution 
has  accordingly  been  productive  of  very 
different  results.     While  the  chief  objects 


era] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


599 


of  the  commercial  interests  in  Europe 
was  the  establishment  of  lines  of  steam 
vessels  connecting  the  great  cities  and 
coast  towns  of  the  British  dominions 
with  each  other,  and  with  those  of  the 
Continent,  and  as  the  art  advanced,  to  ex- 
tend the  same  social  and  commercial  ben- 
efit to  the  coasts  of  the  chief  countries  of 
Europe,  so  as  to  stimulate  the  social  inter- 
course of  nations  too  long  disunited  and 
struggling  in  unprofitable  warfare,  and 
thereby  to  diffuse  equally  among  all  the 
the  benefits  of  general  commercial  inter- 
course, America,  standing  alone  in  her 
vast  extent  of  terrritory,  having  no  near 
neighbors  with  whom  to  cultivate  social 
or  commercial  relations,  regarding  her 
immense  country  intersected  by  some  of 
the  most  noble  rivers  in  the  world,  en- 
riched by  the  largest  sheets  of  inland  wa- 
ter which  can  be  found  upon  the  globe — 
thus  situated,  she  saw  that  inland  navi- 
gation, river  and  lake  transport,  was  the 
great  application  of  steam  by  which  her 
rising  and  enterprising  population  would 
be  most  benefited,  and  by  which  the  ne- 
cessary intercourse  could  be  maintained 
between  her  great  western  emporiums 
erected  on  the  banks  of  the  Mississippi 
and  Ohio ;  her  more  northern  settlements 
on  the  coasts  of  the  gigantic  lakes  Ontario, 
Erie,  Michigan,  and  others ;  and  on  the 
eastern  rivers,  the  Hudson,  the  Delaware, 
and  the  Susquehanna.  It  was,  therefore, 
to  the  construction  of  steamboats  suita- 
ble to  such  internal  navigation  that 
American  genius  was  directed;  and  in 
this  it  has  been  eminently  successful 
above  every  other  country  in  the  world. 
Our  river  steamers  are,  in  general, 
long,  narrow  boats  with  a  small  draught 
of  water,  supporting  a  platform  or  deck 
of  vast  magnitude  projecting  on  either 
side  considerably  beyond  the  limits  of 
the  boat  on  which  it  rests.  The  paddle 
wheels  are  large,  and  are  impelled  by 
single  or  double  engines  placed  with  their 
boilers  and  machinery  above  the  deck.  The 
engines  are  almost  universally  non-con- 
densing high-pressure  engines,  and 
many  of  them  are  worked  expansively. 
The  fuel  is  generally  wood  ;  but  in  many 
cases,  especially  in  the  eastern  vessels, 
coal.  Owing  to  the  form  of  the  boats, 
and  the  smooth  water  in  which  they 
work,  a  much  greater  average  speed  has 
been  obtained  than  in  the  sea-going 
steamers  of  Europe.  On  the  Hudson, 
between  New- York  and  Albany,  where 
steam  navigation  first  commenced,  are 
the  fastest  steamers  in  the  United  States ; 
and  it  is  probable  that  if  the  average  speed 


of  these  vessels,  taken  in  all  circumstan- 
ces of  weather  and  tide,  be  stated  at  18 
or  20  geographical  miles  an  hour,  it  is 
not  overrated ;  and  in  one  instance  lately 
(the  Reindeer),  the  passage  between  the 
two  cities  was  made  at  the  rate  of  24  miles 
per  hour. 

The  Mississippi  is  navigated  by  many 
hundred  steamers  of  very  large  tonnage. 
This  steam  traffic  is  carried  on  through  a 
distance  of  nearly  2000  miles  from  the 
mouth  at  New  Orleans.  The  towns  of 
Natchez,  Cincinnati,  Louisville,  Pitts- 
burgh, and  numerous  others,  maintain, 
by  this  means,  an  easy  and  constant  in- 
tercourse with  the  capital  of  the  Southern 
States. 

The  steamers  of  the  Mississippi  vary  in 
1  magnitude  from  100  to  above  1000  tons, 
and,  unlike  the  light  mould  of  the  Hudson 
steamers,  they  are  heavily  built,  so  as  to 
give  them  abundant  tonnage  for  goods. 
!  They  are  built  with  a  flat  bottom,  with  a 
J  draught  of  from  6  to  8  feet  of  water.     A 
|  deck  is  supported  by  the  hull  at  about  5 
|  feet  above  the  level  of  the  water,  and  the 
!  space  in  the  hull  under  this  deck  is  ap- 
!  propriated  to  the  cargo.    The  whole  of 
|  the  steam  machinery  is  placed  on  this 
deck,  the  engine  standing  in  the  middle 
of  the  vessel,  and  the  boilers  and  fur- 
naces towards  the  bow. 

The  engines  are  constructed  with  very 
small  cylinders,  worked  with  steam  of 
great  pressure.  The  diameter  of  the  cyl- 
inder is  often  under  18  inches,  while  the 
length  of  stroke  is  from  5  to  6  feet.  The 
safety-valve  is  usually  loaded  with  100  lbs. 
per  square  inch,  which,  at  the  discretion 
of  the  captain,  is  sometimes  increased  to 
150  lbs.  Some  of  the  large  boats  on  the 
Mississippi  are  equal  in  magnitude  to 
those  on  the  Hudson,  having  a  length  of 
260  feet,  and  a  breadth  of  beam  of  30  feet. 
With  this  great  magnitude  of  deck  and  a 
capacity  of  not  less  than  1000  tons,  they 
do  not  draw  above  8  feet  of  water. 

The  dimensions  of  the  steamers  which 
ply  on  the  Hudson  are  generally  as  follows : 
The  length  of  deck  from  150  *to  300  feet ; 
the  breadth  of  beam  from  20  to  36  feet ; 
and  the  depth  of  the  hold  from  8  to  10 
feet.  They  are  generally,  but  not  always, 
worked  by  a  double  engine  ;  the  length 
of  stroke  is  never  less  than  8  feet,  but  the 
most  common  length  is  10  feet;  the  di- 
ameter of  the  piston  varies  from  40  to  66 
inches,  and  the  diameter  of  the  paddle 
wheels  from  20  to  25  feet ;  the  breadth 
or  rather  the  thickness  of  the  wheel,  va- 
ries from  12  to  14  feet,  giving  a  great  ex- 
tent   of  surface  to    the   paddle-boards 


600 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[STH 


draught  of  water  of  these  boats  varies 
from  4  to  6  feet ;  the  steam  is  generally 
worked  expansively,  being  cut  off  at  half 
the  stroke,  and  often  sooner ;  the  wheels 
are  said  to  make  on  an  average  from  25 
to  30  revolutions  per  minute. 

The  progress  which  steam  navigation 
has  made  upon  our  lakes  and  western 
rivers  is  almost  incredible.  But  a  few 
years  past,  and  all  the  trade  of  the  Wil- 
derness of  the  West  was  carried  down 
the  inland  waters  by  lumber  boats  and 
vessels  of  small  draught  and  tonnage. 

In  1811,  the  first  steamboat,  the  Orleans, 
•  was  launched  at  Pittsburgh,  on  the  Ohio. 

In  1818,  the  WalkintKe  Water  appear- 
ed upon  Lake  Erie;  and  in  1819,  she 
floated  over  Lake  Huron. 

In  1826,  the  first  steamer  was  seen  at 
Lake  Michigan ;  and 

In  1832,  a  steamboat  first  touched  at 
Chicago. 

At  the  present  time  the  vessels  on  the 
Mississippi,  the  Ohio,  and  their  tribu- 
taries, are  over  600,  with  a  tonnage  of 
140,000  tons,  a  larger  amount  than  is  at 

})resent  engaged  in  the  coast  trade  of  Eng- 
and.  In  1849,  the  United  States  Sen- 
ate printed  a  document,  which  estimates 
the  commerce  of  the  Western  rivers  at 
$256,233,840  for  that  year.  The  com- 
merce of  the  lakes  is  now  equal  to  nearly 
$200,000,000,  the  amount  of  which,  is  in 
a  great  degree  owing  to  the  existence  of 
steam  navigation. 

There  were  built  in  1850,  161  steam 
vessels,  and  employed  in  trade  in  the 
United  States,  which*  are  thus  distributed 
in  the  various  states  : — Maine,  6 ;  Massa- 
chusetts, 2 ;  Vermont,  1 ;  Connecticut,  1 ; 
Khode  Island,  1 ;  New- York,  32 ;  New- 
Jersey,  3;  Pennsylvania,  31;  Delaware, 
1  ;  Maryland,  4;  Virginia,  5;  North  Car- 
olina, 5  ;  Georgia,  3  ;  Louisiana,  4 ;  Ken- 
tucky, 34 ;  Missouri,  5 ;  Illinois,  1 ;  Ohio, 
16;  Michigan,  3;  Texas,  1;  Oregon,  2. 
Total  161.  Which  does  not  include  those 
in  the  California  trade,  nor  those  lately 
put  on  Lake  Nicaragua. 

The  subjoined  chronological  outline  of 
the  progress  of  steam  will  prove  interest- 
ing:— 

1663.  The  Marquis  Worcester  gave  the  first  no- 
tion of  a  steam-engine. 

1710.  Newcomen  (a  barber)  made  the  first  en- 
gine. 

1718.  Savary  first  applied  it 

1736.  Steam  navigation  was  first  proposed. 

1764  Watt  made  the  first  perfect  English  en- 
gine. 

1778.  T.  Paine  proposed  to  apply  it  to  America. 

1781.  The  Marquis  Joffruy  constructed  a  steam- 
vessel  on  the  Kiver  Saone. 


1782.  Rumsey  propelled  a  boat  by  steam  at 
New- York. 

1787.  John  Fitch  navigated  a  boat  on  the  Dela- 
ware. 

1789.  William  Symington  voyaged  on  the  Clyde 
in  a  steam  vessel.    1802.  This  was  repeated. 

1793.  Oliver  Evans,  of  Philadelphia,  construct- 
ed a  locomotive  to  travel  on  turnpike  roads. 

1807.  Fulton  made  the  first  steam  voyage  from 
New- York  to  Albany  at  the  rate  of  five  miles 
per  hour  in  the  Clermont. 

1819.  The  Savannah  steamer  crossed  from 
New- York  to  Liverpool,  and  thence  to  Prussia. 

1838.  April  4th.  The  Sirim  left  Cork  for  New- 
York,  arrived  April  13d,  steaming  161  miles 
a  day. 

1838.  April  8th.  The  Great  Western  left  Bristol 
for  New- York,  arrived  April  23d,  steaming 
208  miles  a  day. 

There  are  now  (1851)  regular  lines  of 
steamships  established  between  New- 
York,  Boston,  and  Philadelphia,  on  this 
side,  and  Liverpool,  Southampton,  Ha- 
vre, and  Bremen,  in  Europe.  Up  to 
1838,  the  carriage  of  the  mails,  as  well  as 
of  freight  and  passengers,  between  this 
country  and  Europe,  was  almost  wholly 
confined  to  the  New- York  sailing-pack- 
ets. Erom  1840  to  1850,  the  mails,  and 
a  large  portion  of  the  passengers,  were 
monopolized  by  the  English  (Cunard) 
steamers.  Steamships  of  other  English 
companies  were  partially  successful  in 
this  trade,  but  had  all  been  withdrawn 
in  1850,  when  the  American  "  Collins' 
line"  of  steamships,  with  the  U.  S.  gov- 
ernment contracts  for  carrying  the  mails, 
commenced  running  from  New- York  to 
Liverpool.  The  ships  of  this  line  are 
larger  than  those  of  the  Cunard  Com- 
pany, and  have  proved  themselves  among 
the  fastest  ocean  steamers  afloat — two  of 
them,  the  Baltic  and  Pacific,  having 
crossed  the  Atlantic  in  9  days  and  13  to 
20  hours.  The  dimensions  of  three  of 
these  vessels  are  as  follow : 


Atlantic. 

Pacific. 

Baltic. 

Length  on  deck .... 
Breadth  of  beam... 

Depth  of  hold 

Tonnage  (Cust.  H.). 
(Carpen- 

Feet. 

285 

45J 

32 

2,771 

3,040 
20 

95  in. 
9  ft. 

800 

35  ft. 
124 

725 

Feet. 

284 

45 

32 

2,686 

2,900 
20 

95  in. 
9  ft. 

800 

36 
111 

720 

Feet. 
287 

45 
32 

2,718 

2,920 
20 

Diameter  of  cylinder 
Length  of  stroke  ... 
Nominal  horse  pow- 
er of  both  engines 
Diameter  of  paddle- 

95  in. 
10  ft. 

828 

36 

Lenjrth  of  paddles.. 
Immersed    midship 

iii 

720 

8TE] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


601 


The  obvious  peculiarity  of  these  ves- 
sels is  the  absence  of  bowsprit  and  jib- 
boom.  The  cost  of  the  Pacific  is  estima- 
ted at  $575,000. 

It  is  likely  that,  as  far  as  the  purposes 
of  commerce  are  concerned,  the  use  of  the 
screw  propeller  will  be  yet  generally  adopt- 
ed, and  ultimately  supersede  paddle 
ships.  It  has  some  advantages  over  the 
paddle.  The  revolving  screw  was  first 
applied  by  Archimedes  as  a  power  to 
raise  water. 

An  important  application  of  this  form 
of  screw  nas  been  made  within  these  few 
years  to  steam  navigation.  An  import- 
ant use  to  which  screw  propellers  nave 
also  been  advantageously  applied  is  as  an 
auxiliary  power  for  occasional  use  during 
calms  ana  contrary  winds  for  sailing  ves- 
sels. The  largest  screw  steamer  con- 
structed was  the  Great  Britain,  the  bur- 
then 3,000  tons,  and  the  engines  1,000 
horse  power.  It  had  a  screw  propeller 
154  feet  in  diameter,  with  six  arms 
mounted  in  the  stern,  and  capable  of  be- 
ing turned  with  great  rapidity.  It  was 
fitted  afterwards  with  a  stronger  propel- 
ler, weighing  several  tons,  and  having 
four  arms.  In  April,  1850,  the  first  screw 
steamer  started  from  Glasgow  to  New- 
York.  An  American  Company  are  build- 
ing them  for  the  emigrant  traffic  from 
Liverpool  to  New-York. 

A  screw  with  an  increasing  pitch  is 
generally  preferable.  By  the  word  pitch 
is  meant  the  distance  between  the  threads 
of  the  screw.  If  the  blades  of  the  propel- 
ler are  bent  so  as  to  be  semewhat  hollow, 
this  makes  it  of  an  increasing  pitch.  The 
advantage  of  this  shape  is  tnat  each  in- 
creasing portion  of  the  screw  overtakes 
the  disturbed  water,  and  so  becomes 
effective.  Woodcroft's  screw,  which  is 
of  this  kind,  was  placed  in  the  Great 
Britain  before  her  last  voyage.  The 
Sarah  Sands,  now  coasting  along  the  Pa- 
cific, in  the  California  trade,  of  1,300  tons, 
has  2  oscillating  engines,  of  180  horse 
power,  driving  by  direct  action  a  Wood- 
croft's screw  of  4  blades  and  14  feet  di- 
ameter. She  reached  New-York  from  Li- 
verpool in  20  days,  and  returned  in  14  days. 
Commodore  Skinner,  in  a  late  report, 
recommends  the  building  of  propellers 
by  this  government,  and  the  French  board 
have  issued  a  similar  recommendation. 

All  the  new  coasting  vessels  now  being 
built  in  England,  are  propellers ;  and  so 
many  improvements  have  been  made  that 
they  are  now  almost  equal  to  the  paddle 
steamers.    The  city  of  Philadelphia  ap- 


pears to  be  the  great  American  port  for 
building  propellers. 

A  great  feat  was  performed  not  long 
ago  by  a  propeller  built  on  the  Clyde. 
The  Admiral,  a  paddle  steamer  of'  700 
tons  and  300  horse  power  engines,  left 
Greenock  for  Liverpool,  and  was  followed 
shortly  after  by  the  Arno,  a  screw  pro- 
peller of  750  tons  and  150  horse  power, 
designed  and  built  by  Messrs.  Wood  ana 
Reid,  at  Port  Glasgow,  and  intended  for 
the  Mediterranean  trade.  The  Admiral 
had  a  start  of  from  two  to  three  miles, 
and  during  the  passage  down  the  Clyde 
gained  a  little  on  her  adversary,  owing  to 
a  strong  head-wind  which  prevailed.  On 
getting  into  moi'e  open  water,  under  a  lit- 
tle alteration  of  the  course  of  each  vessel, 
the  more  ample  spread  of  canvass  by  the 
screw  boat  told  greatly  on  her  speed  and 
she  gained  considerably  on  the  Admiral, 
and  both  went  into  Liverpool  together. 
The  Arno's  engines  attained  a  speed  of 
60  revolutions  per  minute.  She  carried 
600  tons  of  coal,  and  the  average  speed 
was  14  miles  per  hour. 

STEAM  THRASHING  MACHINE,  is 
a  thrashing  machine  having  rotary  mo- 
tion given  to  its  beaters,  by  a  steam  en- 
gine applied  to,  or  suitably  stationed  in 
relation  to  it.  Its  construction  is  in  no- 
wise different  to  that  of  the  common 
thrashing  machine,  which  is  driven  by 
horse  power  or  bv  a  man  turning  a  crank. 
See  THRASHING  MACHINE.  Motion 
is  communicated  from  the  engine  by  a 
belt  or  by  gearing  in  the  same  manner  as 
to  other  machinery. 

STEAM-ENGINE  PLOUGHS  have, 
under  various  modifications,  been  tried 
in  England  and  Scotland,  but  owing  to 
practical  difficulties,  have  never  been  very 
successful.  The  ingenuity  of  man,  how- 
ever, may  yet  overcome  all  the  obstacles 
which  seem  to  prevent  its  success. 

STEAM-GAUGE.    An  instrument  for 
indicating  the  pressure  within  a  steam- 
boiler,  by  means  of  a  bent  tube  partially 
filled  with  mercury,  one  end  ot  which 
springs  from  the  boiler,  while  the  other 
is  exposed  to  the  air  ;  so  that  the  steam, 
by  its  pressure,  raises  the  mercury  in 
the  straight  limb  of  the  tube  to  a  height 
'above  the  common  level,  proportioned  to 
that  pressure.    An  iron  float  and  index 
|  are  usually  added  for  the  convenience  of 
I  observation. 

STEAM-GOVERNOR.    (See  Go- 

|    VERNOB.) 

STEAM-GUN,    or    Steam     Generator. 
i  Perkin's  Steam  Generator  consists  of  a 


26 


602 


CYCLOPEDIA    OF    THE    USEjAJL    ARTS. 


[STE 


copper  globe  or  cylinder,  three  inches 
thick,  holding  eight  gallons,  and  com- 
petent to  sustain  an  explosive  action  of 
4000  lbs.  to  the  inch.  He  heats  this  ball 
to  a  white  heat,  and  forces  the  water  into 
contact  with  the  metal,  so  as  to  get  steam 
with  a  pressure  of  500  lbs.  to  the  square 
inch.  The  valve  bears  560  lbs.,  and  the 
steam  which  flashes  from  it,  as  other  wa- 
ter is  injected,  acts  with  a  force  exceed- 
ing 450  lbs.  By  flashes  of  this  steam, 
Eassed  through  a  gun-barrel,  he  projects 
alls  with  the  force  of  gun-powder,  and 
as  rapidly  as  100  in  a  minute,  forming 
one  of  the  most  destructive  missiles  of 
war  ever  invented,  and  such  as,  if  used, 
would  soon  put  an  end  to  all  war.  He 
asserts  that  more  persons  have  been 
killed  by  low  than  by  high  pressure  boil- 
ers in  England,  and  that  such  has  de- 
cidedly been  the  case  in  America. 

It  appears,  by  his  experiments,  that 
water  does  not  approach  the  surface  of 
red-hot  iron  at  a  white  heat,  and  that  it 
does  not  come  into  contact  with  the  iron 
till  after  six  evaporations,  whose  time 
varies  from  90  to  12  seconds;  but  the 
seventh,  which  evaporates  in  6  seconds, 
is  in  contact,  and  made  in  6  seconds,  and 
this  he  calls  the  evaporating  point. 

STEAM  H  A  M  M  E  <  or  Cyclopean 
Forge  Hammer,  is  the  invention  of  Mr. 
Nasmyth,  of  Patricrofc,  near  Manchester, 
England.  The  hammer  is  a  huge  block 
of  cast  iron,  sometimes  weighing  as  much 
as  six  tons.  It  is  attached  by  an  elastic 
joint  to  the  lower  end  of  the  rod  of  a 
piston  working  in  a  steam  cylinder,  the 
rod  passing  through  a  stuffing  box  in  the 
cylinder  bottom.  The  blow  is  given  by 
admitting  steam  under  the  piston,  and 
raising  it  and  the  hammer  also,  and  then 
suddenly  cutting  off  the  supply  of  steam 
and  opening  a  communication  with  the 
atmosphere  by  a  valve  provided  for  the 
purpose.  The  hammer  then  descends  of 
its  own  weight.  Its  blow  can  be  regula- 
ted with  the  greatest  nicety,  by  the  height 
of  its  ascent,  the  momentum  of  force 
of  the  blow,  increasing  with  the  fall.  The 
anvil  upon  which  the  hammer  strikes,  in 
some    cases,    weisrhs   thirty  tons. 

STEAM,  HEATING  BY.  It  has  been 
ascertained  that  one  cubic  foot  of  boiler 
will  heat  about  2000  cubic  feet,  12*  feet 
each  way,  to  an  average  heat  of  about 
70°  or  80°  Fahr.  And  one  square  foot 
of  surface  of  steam-pipe  is  adequate  to 
the  warming  of  200  cubic  feet,  6  each 
way.  This  quantity  is  adapted  to  a  well- 
finished  ordinary  brick  or  stone  build- 
ing.   Cast-iron  pipes  are  preferable  to  all 


others  for  the  diffusion  of  heat,  the  pipes 
being  distributed  within  a  few  inches  of 
the  floor. 

Steam  is  used  extensively  for  drying 
muslin  and  calicoes.  Large  cylinders 
are  filled  with  it,  which,  diffusing  in  the 
apartment  a  temperature  of  100°  or  130°, 
rapidly  dry  the  suspended  cloth.  Expe- 
rience has  shown  that  bright  dyed  yarns, 
like  scarlet,  dried  in  a  common  stove- 
heat  of  128°,  have  their  color  darkened, 
and  acquire  a  harsh  feel  ;  while  similar 
hanks,  laid  on  a  steam-pipe  heated  up  to 
165°,  retain  the  shads  and  lustre  they 
possessed  in  the  moist  state.  Besides, 
the  people  who  work  in  steam-drying 
rooms  are  healthy,  while  those  who  were 
formerly  employed  in  the  stove-heated 
apartments  became,  in  a  short  time,  sick- 
ly and  emaciated.  The  heating,  by  steam, 
of  large  quantities  of  water,  or  other  li- 
quids, either  for  baths  or  manufactures, 
may  be  effected  in  two  ways :  the  steam- 
pipe  may  be  plunged,  with  an  open  end, 
into  the  water-cistern;  or  the  steam  may 
be  diffused  around  the  liquid  in  the  in- 
terval between  the  wooden  vessel  and 
the  interior  metallic  case.  The  second 
mode  is  of  universal  applicability. 

Cooking  food,  both  for  man  and  cattle, 
is  another  useful  application  of  steam  ; 
for  it  is  the  most  effectual  carrier  of  heat 
that  can  be  conceived,  depositing  it  only 
on  such  bodies  as  are  colder  than  boiling 
water.  Chambers  filled  with  steam,  heat- 
ed to  about  125°  Fahr.,  have  been  intro- 
duced, with  advantage,  into  medical 
practice,  under  the  name  of  Vapor-baths. 

STEARIC  ACID,  improperly  called 
Steakine,  is  the  solid  constituent  of  fatty 
substances,  as  of  tallow  and  olive  oil, 
converted  into  a  crystalline  mass  by  sa- 
ponification with  alkaline  matter,  and  ab- 
straction of  the  alkali  by  an  acid.  By 
this  process,  fats  are  convertible  into 
three  acids,  called  Stearic,  Margaric,  and 
Oleic;  the  first  two  being  solid,  and  the 
last  liquid.  The  stearine,  of  which  the 
adamantine  and  factitious  wax  candles 
are  made,  consists  of  the  stearic  and 
margaric  acids  combined.  These  can  be 
separated  from  each  other  only  by  the 
agency  of  alcohol,  which  holds'the" mar- 
garic acid  in  solution  after  it  has  depo- 
sited the  stearic  in  crystals.  Pure  stearic 
acid  is  prepared,  according:  to  its  dis- 
coverer, Chevreul,  in  the  following  way: 
— Make  a  soap,  by  boiling  a  solution  of 
potash  and  mutton-suet  in  the  proper 
equivalent  proportions  (see  Soap)  ;  dis- 
solve one  part  of  that  soap  in  6  parts  of 
hot  water,  then  add  to  the  solution  40  or 


ste] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


603 


50  parts  of  cold  water,  and  set  the  whole 
into  a  place  whose  temperature  is  about 
52°  Fahrenheit.  A  substance  falls  to  the 
bottom,  possessed  of  pearly  lustre,  con- 
sisting of  the  bi-stearate  and  bi-marga- 
rate  of  potash ;  which  is  to  be  drained 
and  washed  upon  a  filter.  The  filtered 
liquor  is  to  be  evaporated,  and  mixed 
with  the  small  quantity  of  acid  necessary 
to  saturate  the  alkali  left  free  by  the  pre- 
cipitation of  the  above  bi-salts.  On  ad- 
ding water  to  it  afterwards,  the  liquor 
affords  a  fresh  quantity  of  bi-stearate 
and  bi-margarate.  By  repeating  this 
operation  with  precaution,  we  finally  ar- 
rive at  a  point  when  the  solution  con- 
tains no  more  of  these  solid  acids,  but 
only  the  oleic.  The  precipitated  bi-salts 
are  to  be  washed  and  dissolved  in  hot  al- 
cohol, of  specific  gravity  0'820,  of  which 
they  require  about  24  times  their  weight. 
During  the  cooling  of  the  solution,  the 
bi-stearate  falls  down,  while  the  greater 
part  of  the  bi-margarate,  and  the  re- 
mainder of  the  oleate,  remain  dissolved. 
By  once  more  dissolving  in  alcohol,  and 
crystallizing,  the  bi-stearate  will  be  ob- 
tained alone  ;  as  may  be  proved  by  de- 
composing a  little  of  it  in  water  at  a 
boiling  heat,  with  muriatic  acid,  letting 
it  cool,  washing  the  stearic  acid  obtained, 
and  exposing  it  to  heat,  when,  if  pure,  it 
will  not  fuse  in  water  under  the  15Sth 
degree  of  Fahrenheit's  scale.  If  it  melts 
at  a  lower  heat,  it  contains  more  or  less 
margaric  acid.  The  purified  bi-stearate 
being  decomposed  by  boiling  in  water 
along  with  any  acid,  as  the  muriatic,  the 
disengaged  stearic  acid  is  to  be  washed 
by  melting  in  water,  then  cooled  and 
dried. 

Stearic  acid,  prepared  by  the  above 
process,  contains  combined  water,  from 
which  it  cannot  be  freed.  It  is  insipid 
and  inodorous.  After  being  melted  by 
heat,  it  solidifies  at  the  temperature  of 
158°  Fahrenheit,  and  affects  the  form  of 
white  brilliant  needles  grouped  together. 
It  is  insoluble  in  water,  but  dissolves  in 
all  proportions  in  boiling  anhydrous  al- 
cohol, and  on  cooling  to  122°,  crystallizes 
therefrom  in  pearly  plates ;  but  if  the 
concentrated  solution  be  quickly  cooled 
to  112°,  it  forms  a  crystalline  mass.  A 
dilute  solution  affords  the  acid  crystal- 
lized in  large  white  brilliant  scales.  It 
dissolves  in  its  own  weight  of  boiling 
ether  of  0-727,  and  crystallizes  on  cooling 
in  beautiful  scales  of  changing  colors.  It 
distils  over  in  vacuo  without  alteration ; 
but  if  the  retort  contains  a  little  atmos- 
pheric air,  a  small  portion  of  the  acid  is 


decomposed  during  the  distillation ;  while 
the  greater  part  passes  over  unchanged, 
but  slightly  tinged  brown,  and  mixed 
with  traces  of  empyreumatic  oil.  When 
heated  in  the  open  air,  and  kindled, 
stearic  acid  burns  like  wax.  It  contains 
3*4  per  cent  of  water,  from  which  it  may 
be  freed  by  combining  it  with  oxide  of 
lead.  When  this  anhydrous  acid  is  sub- 
jected to  ultimate  analysis,  it  is  found  to 
consist  of — 80  of  carbon,  12-5  hydrogen, 
and  7'5  oxygen,  in  100  parts.  Stearic 
acid  displaces,  at  a  boiling  heat  in  water, 
carbonic  acid  from  its  combinations  with 
the  bases  ;  but  in  operating  upon  an  al- 
kaline carbonate,  a  portion  of  the  stearic 
acid  is  dissolved  in  the  liquor  before  the 
carbonic  acid  is  expelled.  This  decom- 
position is  founded  upon  the  principle, 
that  the  stearic  acid  transforms  the  salt 
into  a  bicarbonate,  which  is  decomposed 
by  the  ebullition. 

Stearine  is  made,  in  this  country,  al- 
most exclusively  from  lard,  which  fur 
nishes  about  two-sevenths  of  its  weight ; 
the  remaining  five-sevenths  being  manu- 
factured into  lard  oil. 

Lime  is  the  material  used  to  saponify 
stearine,  according  to  the  old  patent  pro- 
cess of  Gay  Lussac,  the  celebrated  French 
chemist ;  the  process  being  effected  by 
several  hours'  boiling,  and  the  decompo- 
sition of  the  lime-soap  is  then  effected 
by  sulphuric  acid. 

The  cakes  of  crude  stearine — about 
5,000  lbs.  at  a  time — are  then  melted  and 
saponified;  the  lime-soap  decomposed; 
the  stearine  acid  washed  and  cast  into 
slabs  or  cakes  of  one  by  two  feet  in  di- 
mensions, and  two  inches  thick.  These 
are  then  pressed,  cold,  in  powerful  hy- 
draulic presses,  which  squeezes  out  a 
portion  of  oleine — the  red  oil  of  com- 
merce. They  are  pressed  a  second  time 
in  the  hot  presses,  which  are  still  more 
powerful  than  the  others.  They  are  af- 
terwards steamed,  drawn  off  into  pans 
while  hot,  and  bleached,  strained  through 
cloths  into  tin  pans,  and  when  it  cools, 
forms  blocks  of  a  beautiful  white  wax 
appearance. 

STEATITE  (Soapstone)  is  a  mineral 
of  the  magnesian  family.  It  has  a  gray- 
ish-white or  greenish-white  color,  often 
marked  with  dendritic  delineations,  and 
occurs  massive,  as  also  in  various  suppo- 
sitious crystalline  forms  ;  it  has  a  dull  or 
fatty  lustre  ;  a  coarse  splintery  fracture, 
with  translucent  edges;  a  shining  streak ; 
it  writes  feebly ;  is  soft,  and  easily  cut 
with  a  knife,  but  somewhat  tough  ;  does 
not  adhere  to  the  tongue ;    feels  very 


604 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[STE 


greasy ;  infusible  before  the  blow-pipe ; 
specific  gravity  from  2-6  to  2*8.  It  con- 
sists of — silica,  44  ;  magnesia,  44  ;  alu- 
mina, 2  ;  iron,  7*3  ;  manganese,  l'S  ; 
chrome,  2  ;  with  a  trace  of  lime.  It  is 
found  frequently  in  small  contempora- 
neous veins  that  traverse  serpentine  in 
all  directions,  as  in  Shetland,  in  the 
limestone  of  Icolmkiln,  in  the  serpentine 
of  Cornwall,  in  Anglesey,  in  Saxony,  Ba- 
varia, Hungary,  at^IIoboken,  N.  J.,  and 
in  Vermont.  It  is  used  in  the  manufac- 
ture of  porcelain.  It  makes  the  biscuit 
semi-tran3parent,  but  rather  brittle,  and 
apt  to  crack  with  slight  changes  of  heat. 
It  is  employed  for  polishing  serpentine, 
marble,  gypseous  alabaster,  and  mirror 
glass  ;  as  the  basis  of  cosmetic  powders  ; 
as  an  ingredient  in  anti-attrition  pastes  ; 
it  is  dusted  in  powder  upon  the  inside  of 
boots,  to  make  the  feet  glide  easily  into 
them ;  when  rubbed  upon  grease-spots 
in  silk  and  woollen  clothes,  it  removes 
the  stains  by  absorption  ;  it  enters  into 
the  composition  of  certain  crayons,  and  is 
used  itself  for  making  traces  upon  glass, 
silk,  slabs  for  the  sides  and  back  of 
stores,  &c.  The  spotted  steatite,  cut 
into  cameos  and  calcined,  assumes  an 
onyx  aspect.  Soft  steatite  forms  excel- 
lent stoppers  for  the  chemical  apparatus 
used  in  distilling  or  subliming  corrosive 
vapors.    Lamellar  steatite  is  Talc. 

STEEL.  This  most  useful  and  curious 
substance  is  a  compound  of  iron  and  car- 
bon :  their  relative  proportions  vary  in 
Bteel  of  different  qualities ;  but  in  that 
used  for  ordinary  purposes,  the  carbon 
rarely  exceeds  2  per  cent.,  and  is  gene- 
rally below  it.  Certain  kinds  of  iron  are 
preferred  to  others  in  this  manufacture  ; 
but  this  relates  entirely  to  its  purity, 
which  is  the  essential  requisite.  Steel  is 
made  by  a  process  called  cementation, 
which  consists  in  filling  a  proper  furnace 
with  alternate  strata  of  bars  or  the  purest 
malleable  iron  and  powdered  charcoal : 
atmospheric  air  is  carefully  excluded  from 
the  boxes  containing  the  bars,  and  the 
whole  kept  for  several  days  at  a  red 
heat.  By  this  process  carbon,  probably 
in  the  state  ot  vapor,  penetrates,  and 
combines  in  the  above  small  relative  pro- 
portion with  the  iron,  the  texture  of 
which,  originally  fibrous,  becomes  gran- 
ular, and  its  surface  acquires  a  blistered 
character.  The  malleability  of  steel  falls 
far  short  of  that  of  iron ;  but  it  is  harder, 
and  more  sonorous  and  elastic,  and  sus- 
ceptible of  a  higher  polish,  and  has  less 
tendency  to  rust.  At  a  red  heat  it  ad- 
mits of  hammering  into  various  forms, 


and   of  being  welded  or  united  by  the 
blows  of  the  hammer  to  another  piece  of 
steel  or  iron.    Blistered  steel,  rolled  or 
beaten  down  into  bars,  forms  shear  steel  • 
and  if  melted,  cast  into  ingots,  and  again 
rolled  out  into  bars,  it  forms  cast  steel, 
which,    when   well    prepared,    has    the 
great  recommendation  of  perfect  unifor- 
mity of  texture,  and  a  finer  and  closer 
grain.      The  peculiarity  of  steel,   upon 
which  its  high  value  in  the  arts  in  great 
measure  depends,  is  its  property  of  be- 
coming, by  sudden  quenching  in  water, 
when  at  a  bright  red  heat,  extremely 
hard,  and  of  being  again  softened  down 
to  any  requisite  degree  by  the  application 
of  a  certain  temperature,  which  may  be 
indicated  by  a  thermometer,  commencing 
at  about  800°,  and  terminating  at  a  dull 
red  heat.     This  process  is  often  called 
tempering;  and  the  workman  is  some- 
times guided  in  the  extent  to  which  it  is 
carried  by  the  color  of  the  polished  sur- 
face of  the  heated  steel,  which  is  at  first 
rendered  by  a  pale  straw  tint,  then  yel- 
low, brownish,  purple,  and  blue,  as  the 
temperature  rises  from  one  extreme  to 
the  other.    The  latter  color  indicates  ex- 
treme softness  and  elasticity,  such  as  be- 
longs   to    watch-springs,    some    sword- 
blades,  &c. ;  pale  straw  indicates  great 
hardness,  as  for  razor  blades ;  yellow  is 
somewhat  softer,  and  shows  a  fit  temper 
for  penknives ;  and  the  incipient  blues 
announce  the  temper  that    oelongs    to 
coarser  cutting  instruments,  and  to  table 
knives,   any  of  which,   made  of  hard 
steel,  would  soon  get  spoiled  and  notch- 
ed, but  the  edges  of  which,  when  duly 
tempered,   resist    breaking  on   the   one 
hand,  and  bending  on  the  other.    When 
a  large  mass  of  steel  is  hardened  by 
quenching  in  water,  it  undergoes  a  cer- 
tain degree  of  expansion,  so  that  the  spe- 
cific gravity  of  hard  steel  is  somewnat 
less  than  that  of  soft.     It  has  been  at- 
tempted to  improve  the  quality  of  steel 
for  certain  purposes  by  adding  to  it  a 
small  portion  of  other  metals  :  hence  the 
term  silver  steel,  &c. ;  but  none  of  these 
alloys  have  on  the  whole  proved  superior 
to  well-made  common  steel.    There  is  a 
kind  of  steel  imported  from  India,  known 
under  the  name  of  wootz,  the  cutting  in- 
struments of  which  are  celebrated  for  the 
toughness  and  durability  of  their  edge. 
It  appears  probable  that  its  peculiarities 
depend  upon  the  presence  of  a  little  alu- 
minum.    When    the   surface   of  some 
kinds   of  steel  is  washed  over  with  a 
weak  acid,  it  acquires  a  peculiar  mottled 
or  damasked  appearance,  as  if  its  texture 


»] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


605 


consisted  of  an  intimate  mixture  of  two 
different  kinds  of  steel,  or  of  fine  fibres 
of  steel  and  iron.  Steel,  alloyed  with  a 
little  nickel,  often  puts  on  this  appear- 
ance ;  but  these  and  some  other  imita- 
tions of  the  celebrated  Damascus  sword- 
blades  have  not  led  to  any  important  im- 
provements in  the  manufacture  of  our 
cutting  instruments. 

The" Shear  steel,  which  derives  its  name 
from  the  accidental  circumstance  of  the 
shears  for  dressing  woollen  cloth  being 
usually  forged  from  it,  is  made  by  bind- 
ing into  a  bundle,  with  a  slender  steel 
rod,  four  parallel  bars  of  blistered  steel, 
previously  oroken  into  lengths  of  about 
18  inches,  including  a  fifth  of  double 
length,  whose  projecting  end  may  serve 
as  a  handle.  This  faggot,  as  it  is  called, 
is  then  heated  in  the  forge-hearth  to  a 
good  welding-heat,  being  sprinkled  over 
with  sand  to  form  a  protecting  filrn  of 
iron  slag,  carried  forthwith  to  the  tilt, 
and  notched  down  on  both  sides  to  unite 
all  the  bars  together,  and  close  up  every 
internal  flaw  or  fissure.  The  mass  being 
again  heated,  and  the  binding  rings 
knocked  off,  it  is  drawn  out  into  a  uni- 
form rod  of  the  size  required.  Manufac- 
turers of  cutlery  are  in  the  habit  of  pur- 
chasing the  blistered  bars  at  the  conver- 
sion furnaces,  and  sending  them  to  tilt 
mills  to  have  them  drawn  out  to  the  pro- 
per size,  which  is  done  at  regular  prices 
to  the  trade  ;  from  5  to  8  per  cent,  dis- 
count being  allowed  on  the  rude  bars  for 
waste  in  the  tilting.  The  metal  is  ren- 
dered so  compact  oy  the  welding  and 
hammering,  as  to  become  susceptible  of 
a  much  finer  polish  than  blistered  steel 
can  take ;  while  the  uniformity  of  its 
body,  tenacity,  and  malleability,  are  at 
the  same  time  much  increased  ;  by  which 
properties  it  becomes  well  adapted  for 
making  table  knives  and  powerful  springs, 
such  as  those  of  gun-locks.  The  steel  is 
also  softened  down  by  this  process,  pro- 
bably from  the  expulsion  of  a  portion  of 
its  carbon  during  the  welding  and  subse- 
quent heats  ;  and  if  these  be  frequently 
or  awkwardly  applied,  it  may  pass  back 
into  common  iron. 

Cast  steel  is  made  by  melting,  in  the 
best  fire-clay  crucibles,  blistered  steel, 
broken  down  into  small  pieces  of  conve- 
nient size  for  packing  ;  and  as  some  car- 
bon is  always  dissipated  in  the  fusion,  a 
somewhat  highly  converted  steel  is  used 
for  this  purpose.  The  furnace  is  a  square 
prismatic  cavity,  lined  with  fire-bricks, 
12  inches  in  each  side,  and  24  deep,  with 
a  fl-ae  immediately  under  the  cover,  8i 


inches  by  6,  for  conducting  the  smoke 
into  an  adjoining  chimney  of  considera- 
ble height.  In  some  establishments  a 
dozen  such  furnaces  are  constructed  in 
one  or  two  ranges,  their  tops  being  on  a 
level  with  the  floor  of  the  laboratory,  as 
in  brass  foundries,  for  enabling  the  "work- 
men more  conveniently  to  inspect,  and 
lift  out,  the  crucibles  with  tongs.  The 
ash-pits  terminate  in  a  subterraneous 
passage,  which  supplies  the  grate  with  a 
current  of  cool  air,  and  serves  for  emp- 
tying out  the  ashes.  The  crucible  stands, 
of  course,  on  a  sole-piece  of  baked  fire- 
clay; and  its  mouth  is  closed  with  a 
well-fitted  lid.  Sometimes  a  little  bottle- 
glass,  or  blast-furnace  slag,  is  put  into 
the  crucible,  above  the  steel-pieces,  to 
form  a  vitreous  coating,  that  may  tho- 
roughly exclude  tax  air  from  oxidizing 
the  metal.  The  fuel  employed  in  the 
cast-steel  furnace  is  a  dense  coke,  oril- 
liant  and  sonorous,  broken  into  pieces 
about  the  size  of  an  egg,  one  good  charge 
of  which  is  sufficient.  The  tongs  are 
furnished  at  the  fire  end  with  a  pair  of 
concave  jaws,  for  embracing  the  curva- 
ture of  the  crucible,  and  lifting  it  out 
whenever  the  fusion  is  complete.  The 
lid  is  then  removed,  the  slag  or  scoriae 
cleared  away,  and  the  liquid  metal  pour- 
ed into  cast-iron  octagonal  or  rectangular 
moulds,  during  which  it  throws  out  bril- 
liant scintillations. 

Cast  steel  works  much  harder  under 
the  hammer  than  shear-steel,  and  will 
not,  in  its  usual  state,  bear  much  more 
than  a  cherry-red  heat  without  becoming 
brittle  ;  nor  can  it  bear  the  fatigue  inci- 
dent to  the  welding  operation.  It  may, 
however,  be  firmly  welded  to  iron,  through 
the  intervention  of  a  thin  film  of  vitreous 
boracic  acid,  at  a  moderate  degree  of  ig- 
nition. Cast  steel,  indeed,  made  from  a 
less  carburetted  bar  steel,  would  be  sus- 
ceptible of  welding  and  hammering  at  a 
higher  temperature  ;  but  it  would  require 
a  very  high  heat  for  its  preparation  in  the 
crucible. 

Iron  may  be  very  elegantly  plated  with 
cast  steel,  by  pouring  the  liquid  metal 
from  the  crucible  into  a  mould  contain- 
ing a  bar  of  iron  polished  on  one  face. 
In  this  circumstance  the  adhesion  is  so 
perfect  as  to  admit  of  the  two  nietala 
being  rolled  out  together;  and  in  this 
way  the  chisels  of  planes  and  other  tools 
may  be  made,  at  a  moderate  rate  and  of 
excellent  quality,  the  cutting-edge  being 
formed  in  the  "steel  side.  Such  instru- 
ments combine  the  toughness  of  iron 
with  the  hardness  of  steel. 


606 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[STE 


For  correcting  the  too  high  carboniza- 
tion of  steel,  or  of  equalizing  the  too 
highly  converted  exterior  of  a  bar  with 
the  softer  steel  of  the  interior,  the  metal 
requires  merely  to  be  imbedded,  at  a  ce- 
menting heat,  in  oxide  of  iron  or  manga- 
nese ;  the  oxygen  of  which  soon  ab- 
stracts the  injurious  excess  of  carbon,  so 
that  the  outer  layers  may  be  even  con- 
verted into  soft  iron,  while  the  axis  con- 
tinues steely  ;  because  the  decarbonizing 
advances  far  more  rapidly  than  the  car- 
bonizing. 

To  preserve  steel  from  rust,  Stodart's 
method  is  to  wash  with  the  ethereal  so- 
lution of  gold,  or  with  muriate  of  platina. 
In  this  way,  the  breadths  of  polished 
steel  in  grates,  fenders,  &c,  are  pre- 
served ;  and  either  may  be  purchased  of 
chemists,  or  furnishing  ironmongers. 

Steel  heated  a  little  above  the  degree 
necessary  to  temper  it,  becomes  soft,  by 
that  very  operation  of  tempering,  and 
this  process,  for  nealing  it,  is  much  su- 
perior to  the  ordinary  methods.  The 
process  in  no  way  deteriorates  the  steel, 
and  abridges  the  operation. 

The  steel-liar  dening^  alluded  to  pre- 
viously, is  a  very  important  process,  in 
connection  with  steel-engraving  and  die- 
sinking.  The  subject  is  engraved  on 
soft  cast-steel,  and  then  is  hardened  by 
placing  it  in  a  cast-iron  pot,  surrounded 
with  animal  charcoal.  It  is  then  exposed 
to  intense  heat  of  coke  in  an  air-furnace, 
and  afterwards  placed  in  a  vessel  of  cold 
water,  renewed  by  a  current.  It  is  then 
used  to  make  a  puncheon-die  on  other  soft 
steel,  to  be  hardened,  and  this  is  a  matrix 
for  others,  by  which  coin  may  be  struck. 

Every  kind  of  iron  is  not  suited  to  be- 
come steel.  The  iron  which  answers 
best  is  made  at  Danemora,  in  Sweden, 
and  the  whole  produce  of  the  Danemora 
mines,  amounting  to  8000  tons,  is  im- 
ported into  Britain  by  a  single  house,  and 
the  cementation  is  performed  at  Sheffield, 
by  Sanderson  &  Co.,  who  export  steel  to 
all  parts  of  the  world. 

I  or  a  long  time  we  had  to  import  all 
our  steel  from  England,  and  England  had 
to  import  all  her  iron  from  Sweden  to 
make  her  steel.  "Within  the  past  year 
steel  has  been  made  at  the  establishment 
of  the  Adirondac  Steel  Works  in  Jersey 
City,  and  although  these  works  are  com- 
paratively in  their  infancy,  having  been 
in  operation  only  since  last  January,  the 
article  produced  is  preferred,  at  the  same 
price,  for  many  purposes,  to  the  best 
English  cast  steel.  Similar  works  exist 
in  Connecticut. 


The  ore  used  is  produced  from  Essex 
county,  N.  Y.,  at  the  sources  of  the  Hud- 
son, at  an  altitude  of  5,000  feet,  among 
the  Adirondac  Mountains,  and  about  50 
miles  West  from  Lake  Champlain.  Large 
expenditures  have  been  made  by  the 
proprietors  for  the  purpose  of  developing 
the  immense  mineral  resources  of  that 
region. 

The  ore  is  here  converted  into  bar  iron 
and  transported  to  the  Company's  works 
in  Jersey  City  to  be  manufactured  into 
steel.  Its  adaptedness  to  this  purpose 
was  ascertained  by  Joseph  Dixon,  Esq., 
of  Jersey  City,  after  a  protracted  series 
of  experiments  made  with  reference  to 
that  object.  He  also  succeeded  in  the 
use  of  anthracite — supposed  by  English 
manufacturers  impossible  ;  and  then  ap- 
plied himself  to  the  manufacture  of 
black-lead  crucibles  possessing  sufficient- 
ly powerful  refractory  qualities  to  with- 
stand the  heat  of  anthracite  furnaces. 
In  this  too  he  was  successful,  and  his 
pots  are  now  in  use  in  England  and  else- 
where by  the  first  artisans. 

In  these,  the  steel  is  broken  into  small 
pieces,  and  put  into  sixteen  crucibles  of 
a  capacity  of  forty  to  sixty  pounds,  which 
are  placed  in  as  many  small  furnaces 
whose  tops  are  even  with  the  surface  of 
the  floor.  After  the  lapse  of  two  hours, 
the  molten  contents  are  poured  into  in- 
got moulds,  of  various  sizes.  The  steel 
is  then  readily  drawn  out  upon  being  re- 
heated, under  heavy  hammers,  into  oars 
of  any  desired  shape  or  size. 

Edge  tools  may  be  made  with  cast  steel 
faces  upon  iron  by  fixing  a  clean  piece  of 
wrought  iron,  brought  to  a  welding  heat, 
in  the  centre  of  a  mould,  and  then  pour- 
ing in  melted  steel,  so  as  entirely  to  en- 
velope the  iron,  and  then  forging  the 
mass  into  any  shape  required. 

STEERING  APPARATUS.  An  im- 
provement on  the  steering  wheel,  as 
commonly  used  on  shipboard.  Capt. 
C.  F.  Brown,  of  Warren,  Rhode  Island, 
has  invented  a  new  and  ingenious  im- 
provement in  steering  apparatus  for  ves- 
sels, for  which  he  has  taken  measures 
to  secure  a  patent,  and  which  will,  no 
doubt,  arrest  the  attention  of  nautical 
men.  The  head  of  the  rudder  post  is 
made  of  metal,  with  a  helical  groove  run- 
ning down  on  each  side  of  it ;  and  over 
this  is  placed  a  tube  with  two  feathers 
on  its  inside,  fitting  into  the  said  helical 
grooves.  Over  the  top  of  this  is  another 
outside  tube  or  cap,  bolted  by  a  flange 
to  the  deck,  and  on  the  top  is  the  wheel, 
having  for  its  axis  a  screw,  which  works 


*] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


607 


into  a  thread  opening  in  the  second  tube, 
and  as  the  wheel  is  turned  this  second 
tube  is  raised  or  lowered,  and  its  feathers, 
thereby  working  in  the  helical  grooves  of 
the  head  of  the  rudder  post,  turns  it 
roundward  and  from  one  side  to  the 
other,  thus  operating  the  rudder  and 
steering  the  vessel.  The  steering  wheel 
is  horizontal,  and  there  is  an  indicating 
pointer  on  the  post  head,  which,  as  it 
turns,  points  to  an  index,  and  enables 
the  steersman  to  see  every  degree  through 
which  the  rudder  moves.  Of  all  the 
steering  apparatus  that  we  have  ever  seen, 
this  is  the  most  compact  and  beautiful. 

The  steering  apparatus  on  board  the 
Cunard  steamer  Asia,  which  was  in- 
vented by  Messrs.  Frazer  and  Robinson, 

E.  N.,  differs  from  the  foregoing.  It 
consists  in  the  application  to  the  steering 
wheel  of  a  friction  band,  similar  to  that 
used  in  cranes,  which  passes  round  a  pro- 
jecting circumference  inside  the  wheel, 
and  is  brought  down  to  a  pedal  on  the 
deck,  by  pressure,  on  which  any  amount 
of  friction  can  be  put  on  the  wheel.  It 
is  not  desirable  that  the  helm  should  ever 
be  at  a  "  dead  lock,"  without  the  power 
of  yielding  a  little  to  the  shock  of  a  very 
heavy  sea,  as  that  would  endanger  the 
carrying  away  the  rudder.  An  adjusting 
screw  is  therefore  provided,  by  which 
the  amount  of  ultimate  friction  that  can 
be  put  on  the  wheel  is  regulated,  and  not 
left  in  the  power  of  the  steersman.  A 
great  advantage  of  this  invention  is  the 
power  which  it  gives  of  fixing  the  rud- 
ders of  vessels  lying  in  the  tideway  or 
harbor,  and  thereby  preventing  the  con- 
tinual wear  on  the  pintals  of  the  rudder, 
and  in  time  the  loosening  of  the  stern 
framing  of  the  vessel. 

STEELYARD.  A  balance  by  which 
the  weights  of  bodies  are  determined  by 
means  of  a  single  standard  weight.  In 
the  Roman  steelyard,  or  statera,  the 
lever  was  so  constructed  that  the  centre 
of  gravity  was  brought  immediately  over 
the  point  of  support ;  and  the  system  be- 
ing accordingly  balanced  upon  its  fulcrum 

F,  the  effect  of  the  weight  of  the  lever 
was  neutralized.  The  longer  arm  was 
then  divided  into  parts,  each  equal  to 
the  shorter  arm,  and  those  again  equally 
subdivided.  Suppose  now  the  length  of 
the  shorter  arm,  or  the  distance  F  B  to 
be  one  inch,  and  the  constant  weight  P 
to  be  one  pound ;  then  if  P  be  placed  at 
the  distance  of  five  inches  from  F,  it  will 
make  equilibrium  with  a  load  of  five 
pounds  suspended  from  B ;  for,  from  the 
property  of  the  lever,  when  the  equi- 


librium is  established  the  weight  P  is  to 
the  load  at  B  as  the  distance  of  B  from  F 
is  to  the  distance  of  P  from  F.  What- 
ever proportion,  therefore,  F  P  has  to 
F  B,  the  same  proportion  has  the  weight 
suspended  from  B  to  the  constant  weight 

The  steelyard  in  common  use  is  con- 
structed somewhat  differently,  the  beam 
being  seldom  made  so  as  to  balance  itself 
on  the  fulcrum  F  ;  but  the  error  that 
would  arise  on  this  account  is  compen- 
sated by  beginning  the  divisions  at  that 
point  where  the  weight  P  being  placed, 
the  equilibrium  is  established.  If,  there- 
fore, when  P  is  removed  the  longer  arm 
prepondeintes,  the  divisions  commence 
from  a  point  between  F  and  B.  For  the 
purpose  of  increasing  the  range,  there 
are  also  in  general  two  fulcra,  from  either 
of  which  the  beam  may  be  suspended, 
and  two  corresponding  scales  of  division 
are  marked  on  opposite  sides  of  the  longer 
arm. 

For  weighing  heavy  loads  the  steel- 
yard is  a  convenient  instrument ;  but  for 
smaller  weights  it  is  susceptible  of  less 
accuracy  than  the  common  balance.  It 
should  be  constructed  so  that  the  point 
of  support  F,  and  the  point  of  suspen- 
sion at  B,  may  be  in  the  same  straight 
line  with  the  divisions  of  the  beam. 

STENCILLING.  Drawing  upon  walls 
in  water  colors,  by  means  of  a  plate  of 
metal,  on  which  the  device  is  cut  out :  a 
brush  dipped  in  pigment,  and  passed 
over  the  plate,  conveys  the  pigment 
through  the  perforations,  and  forms  the 
pattern. 

STEREOTYPING.  The  invention  of 
stereotyping  has  usually  been  attributed 
in  Europe  to  W.  Ged,  of  Edinburgh, 
about  1780  :  but  there  is  evidence  on  re- 
cord that  in  1779  Cadwallader  Colden,  of 
New- York,  communicated  the  plan  of 
the  art  to  Dr.  Franklin,  then  in  Paris, 
and  the  details  were  by  him  given  to 
Didot,  the  great  printer.  In  1780,  Til- 
losh  and  Foulis  introduced  improve- 
ments :  a  little  later,  various  novelties 
Wfere  added  in  France  under  the  name  of 
polytype.  In  some  of  them  the  form 
was  imitated  by  striking  upon  a  mass  of 
soft  metal  like  clichee  moulds.  Stereo- 
typing, as  now  practised,  became  fully 
established  in  1800.  (See  "  World's 
Progress,"  p.  543.) 

Stereotype  printing  signifies  printing 
by  fixed  types,  or  by  a  cast  typographic 

?late.    This  plate  is  made  as  follows : — 
'he  form  composed  in  ordinary  types, 
and  containing  one,  two,  three,  or  more 


608 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


[STK 


pages,  inversely  as  the  size  of  the  hook, 
being  laid  flat  upon  a  slab,  with  the  let- 
ters looking  upwards,  the  faces  of  the 
tynes  are  brushed  over  with  oil,  or  prefer- 
ably with  plumbago  (black lead).  A  heavy 
iron  rectangular  frame,  with  bevelled 
borders,  adapted  exactly  to  the  size  of 
the  pages,  is  then  laid  down  upon  the 
chasse,  to  circumscribe  its  typography. 
The  frame  resembles  that  of  a  picture, 
and  serves  to  define  the  area  and  thick- 
ness of  the  cast,  which  is  made  by  pour- 
ing the  pap  of  Paris  plaster  into  its  in- 
terior space,  up  to  a  given  line  on  its 
edges.  The  plaster  mould,  which  soon 
sets,  or  becomes  concrete,  is  lifted  gently 
off  the  types  by  the  untwisting  of  a 
screw  at  each  corner,   and  immediately 

f>laced  horizontally  on  shelves  in  an  oven 
leated  to  400°,  when  they  become  per- 
fectly dry  in  two  hours.  As  they  are 
now  friable  and  porous,  they  require  to 
be  delicately  handled.  Each  mould,  con- 
taining generally  two  pages  octavo,  is 
laid,  with  the  impression  downwards, 
upon  a  flat  cast-iron  plate,  called  the  float- 
ing-plate; this  plate  being  itself  laid  on 
the  bottom  of  the  dipping:pan;  which  is 
a  cast-iron  square  tray,  with  its  upright 
edges  sloping  outwards.  A  cast-iron  lid 
is  applied  to  the  dipping-pan,  which  has 
its  corners  cut  off  to  allow  the  melted 
metal  to  flow  in,  and  is  then  secured  in 
its  place.  The  pan  having  been  heated 
to  400°,  by  resting  on  the  melted  metal, 
previous  to  receiving  the  hot  mould,  is 
ready  to  be  plunged  into  the  hath  of 
melted  alloy  contained  in  an  iron  pot 
placed  over  a  furnace,  and  it  is  dipped 
with  a  slight  deviation  from  the  horizon- 
tal plane,  in  order  to  facilitate  the  escape 
of  the  air.  As  there  is  a  minute  space 
between  the  back  or  top  surface  of  the 
mould  and  the  lid  of  the  dipping-pan, 
the  liquid  metal,  on  entering  into  the 
pan  through  the  orifices  in  its  corners, 
floats  up  the  plaster  along  with  the  iron 
plate  on  which  it  had  been  laid,  thence 
called  the  floating-plate,  whereby  it  flows 
freely  into  every  line  of  the  mould, 
through  notches  cut  in  its  edge,  and 
forms  a  layer  or  lamina  upon  its  face,  of 
a  thickness  corresponding  to  the  depth 
of  the  border.  Only  a  thin  metal  film  is 
left  upon  the  back  of  the  mould.  The 
dipping-pan  is  suspended,  plunged,  and 
removed,  by  means  of  a  powerful  crane, 
susceptible  of  vertical  ami  horizontal  mo- 
tions in  all  directions.  When  lifted  out 
of  the  bath,  it  is  set  in  a  water-cistern, 
upon  bearers  so  placed  as  to  allow  its 
bottom  only  to  touch  the  Burface.    Thus 


the  metal  first  concretes  beiow,  while, 
by  remaining  fluid  above,  it  continues 
to  impart  hydrostatic  pressure  during 
the  shrinkage  attendant  upon  refrigera- 
tion. As  it  thus  progressively  contracts 
in  volume,  more  melted  metal  is  fed  into 
the  corners  of  the  pan  by  a  ladle,  in  or- 
der to  keep  up  the  hydrostatic  pressure 
upon  the  mould,  and  to  secure  a  perfect 
impression,  as  well  as  a  solia  cast. 
Were  the  pan  more  slowly  and  equably 
cooled,  by  being  left  in  the  air,  the  thin 
film  of  metal  upon  the  back  of  the  in- 
verted plaster  cake  would  be  apt  to  so- 
lidify first,  and  intercept  the  hydrostatic 
action  indispensable  to  the  purpose  of 
filling  all  the  lines  in  its  face.  The  lid 
of  the  pan  being  taken  off,  the  compound 
cake  of  mould  and  metal  is  removed, 
and  beat  upon  its  edges  with  an  iron 
sledge,  to  detach  the  superfluous  metal. 
The  stereotype  plate  is  then  washed  with 
a  brush  and  water  to  remove  the  ad- 
hering plaster,  and  handed  over  to  the 
picker,  who  planes  its  edges  truly  square, 
turns  its  back  flat  upon  a  lathe,  in 
which  a  steel  cutter  or  knife,  mounted 
on  a  slide  rest,  shaves  off  the  metal  in 
concentric  circles  to  a  determinate  thick- 
ness, and  carefully  removes  the  little 
imperfections  occasioned  by  dirt  or  air 
left  among  the  letters  when  the  mould 
was  cast.  Should  any  of  them  be  da- 
maged in  the  course  of  the  operation, 
they  must  be  cut  out,  and  replaced  by 
soldering  in  separate  types  of  the  same 
size  and  form. 

They  are  then  mounted  on  blocks  of 
wood  to  the  height  of  type. 

In  this  country  a  machine,  similar  to 
that  given  in  this  illustration,  is  used 
for  smoothing  the  back  of  the  plate. 
This  Stereotype  Shavvn,g,  or  Planing  Ma- 
chine, for  equahizing  the  thickness  of 
stereotype  plates,  is  made  of  wrought 
and  cast  iron,  and  rests  upon  a  wooden 
bench.  It  consists  of  a  cast-iron  bed 
plate  planed  perfectly  true  on  tho  face 
and  edges,  with  bearings  projecting 
above  to  receive  a  wrought  iron  shaft 
with  two  case  hardened  pinions  on  it, 
between  the  bearings  and  a  hand  wind- 
lass, with  arms  outside,  on  one  end.  _  A 
sliding  head,  with  knife  attached,  which 
can  be  adjusted  by  set  screws,  has  two 
racks  attached,  by  which  it  is  impelled 
by  the  windlass  and  pinions  back  and 
forward  over  the  stereotype  plate  (which 
is  placed  on  the  bed)  until  it  is  reduced 
to  the  required  thickness. 

STETHOSCOPE.  A  cylinder  of  cedar 
wood  about  12  inches  long,  and  1  in 


CTKJtEOTTPS  SHAVING  OR  PLANING   MM.Iil.VK.       p.  tJllS. 


STO] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


609 


diameter ;  perforated  throughout  its 
length,  having  an  ear-piece  at  one  end 
and  a  funnel-shaped  cavity  at  the  other. 
It  is  used  to  recognize  the  sounds  of  the 
chest  in  health  and  disease. 

STILE.  In  architecture,  the  vertical 
piece  in  framing  or  panelling. 

STILL.  An  apparatus  for  the  distilla- 
tion of  liquids  upon  the  large  scale.  It 
includes  the  body,  or  boiler,  which  is 
iisually  set  in  brick-work  over  a  furnace, 
and  to  which  is  annexed  the  head,  form- 
ing the  communication  between  the  boiler 
and  condenser  or  w  arm -pipe  ;  from  the 
extremity  of  which  the  distilled  liquid 
passes  in  successive  drops,  or  a  small 
continuous  stream,  into  the  recipient. 
There  are  an  infinite  variety  of  stilts  ad- 
apted to  particular  purposes,  of  which 
the  most  important  are  the  distillation  of 
spirituous  liquors. 

STOMACH  PUMP.  A  small  pump  or 
syringe  with  two  apertures,  the  valves  of 
which  are  so  arrauged  as  to  admit  of 
liquids  being  drawn  out  of,  or  injected 
into,  the  stomach,  by  means  of  a  flexible 
tube. 

STORAX.  A  gum-resin,  obtained  by 
incisions  in  the  branches  of  a  small  tree 
which  grows  wild  in  the  countries  about 
the  Mediterranean. 

STOVE.  A  receptacle  for  the  combus- 
tion of  fuel  for  the  purpose  of  heating 
houses,  &c.  The  closed  fire-grate  for 
the  combustion  of  coal,  with  its  various 
appendages,  is  generally  called  a  stove — 
hence  register  stoves,  Bath  stoves,  &c. 
These  are  often,  and  indeed  generally, 
very  unscientifically  constructed,  and 
calculated  to  consume  a  large  quantity  of 
fuel,  with  a  proportionate  waste  of  heat. 
They  are  generally  intended  to  diffuse 
warmth  principally  or  entirely  by  radia- 
tion, and  should  be  placed  as  near  the 
floor  as  possible ;  while  the  different 
parts,  into  the  contact  of  which  the  burn- 
ing fuel  is  brought,  should  be  of  fire- 
brick, or  some  similar  composition,  which 
is  a  bad  conductor,  but  a  good  radiator 
of  heat.  It  is  manifest  that  in  open  fire- 
places the  enormous  volume  ot  hot  air 
which  passes  up  the  chimney  is  not 
available  as  a  source  of  heat ;  hence,  in 
colder  climates,  such  as  that  of  the 
Northern  States,  and  where  greater  econ 
omy  of  fuel  is  studied,  the  fireplace  is 
frequently  closed  in,  and  contained  in  an 
iron  box  which  projects  into  the  room, 
while  the  heated  air  before  it  finally 
enters  the  chimney  is  made  to  circulate 
through  tubes  or  pipes,  to  which  it  com- 
municates much  of  its  excess  of  heat,  and 
26* 


these  again  impart  it  to  the  surrounding 
air.  What  are  termed  in  Europe  German 
stoves,  are  usually  made  upon  such  prin- 
ciples ;  and  in  them  the  fuel  is  often  in- 
troduced, and  the  air  required  for  the 
support  of  its  combustion  admitted,  on 
the  outside  of  the  room  in  which  the 
stove  with  its  flues  and  heating  surfaces 
is  placed. 

In  ArnoWs  stoves  the  heat  is  similar, 
but  more  scientifically  economized.  There 
is  only  enough  air  admitted  to  keep  up 
the  slow  combustion  of  the  fuel,  and  the 
heat  is  communicated  to  the  radiating 
surfaces  of  the  stove ;  so  that  before  the 
air,  which  has  passed  through  the  fuel, 
finally  enters  the  chimney,  it  has  been 
deprived  of  the  greater  part  of  its  availa- 
ble heat.  These  stoves  are  also  so  con- 
structed as,  by  means  of  thermometric  or 
self-acting  registers,  to  adjust  with  much 
nicety  the  supply  of  air,  so  that  neither 
more  nor  less  may  enter  than  is  required 
to  maintain  the  combustion  of  a  given 
quantity  of  fuel. 

In  Feetharri's  air-stoves  the  common 
open  fire  is  retained  ;  but  the  heat  is  to 
a  certain  extent  economized  by  causing 
the  hot  air  before  it  enters  the  chimney, 
to  communicate  a  portion  of  its  heat  to 
an  iron  box,  over  which  a  current  of  air 
passes  and  is  sent  warm  into  the  room. 

It  is  manifest  that  open  fires  must  act 
as  powerful  ventilators,  and  that  the  large 
quantity  of  air  which  is  driven  up  the 
chimney  must  be  supplied  in  some  way 
or  other  through  the  apartment  in  which 
the  fire  is  burning.  This  supply  of  air 
is  generally  left  to  chance,  and  finds  its 
way  into  the  room  by  crevices  in  the 
door-ways  and  window-sashes,  or  between 
the  boards  of  the  floor,  or  any  similar 
accidental  passage  through  which  it  can 
make  its  way  ;  and  as,  in  London  at  least, 
the  air  always  abounds  in  fuliginous  par- 
ticles, these  are  carried  in  along  with  it, 
and  show  its  track  by  the  blacks  which 
it  deposits.  If  this  supply  of  air  is  inad- 
equate, and  it  generally  is  so  in  new  and 
well-built  houses,  in  consequence  of  the 
tightness  of  the  doors,  windows  and  floors, 
the  chimney  of  necessity  smokes,  and  the 
door  or  window  requires  to  be  left  open  to 
prevent  sue*  in  effect.  This  evil  may  usu- 
ally be  efLjtually  prevented  by  admitting 
fresh  air  from  without  through  some  pro- 
per and  adequate  channel,  and  various 
ornamental  or  concealed  apertures  may 
be  contrived  for  the  purpose ;  in  the  best 
arrangement  of  which,  however,  much 
practical  as  well  as  theoretical  skill  is 
often  essential. 


610 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[STR 


"When  rooms  are  warmed  by  German 
or  Arnott's  stoves,  the  ventilating  powers 
of  which  are  very  inferior  to  the  open 
grate,  ventilation  requires  to  be  strictly 
attended  to.  Where  buildings  are  warmed 
by  currents  of  hot  air  sent  np  from  stoves 
on  the  basement  story,  great  attention 
should  also  be  paid  to  ventilation  ;  and  in 
such  cases  the  leading  object  should  be 
to  send  in  a  large  volume  of  air  very  mod- 
erately heated  (to  about  100°),  rather  than 
a  small  quantity  of  very  hot  air ;  the 
latter  does  not  readily  mix  with  the  sur- 
rounding cold  air,  but  forms  a  distinct 
and  rapidly  ascending  column,  which 
does  not  diffuse  itself  where  most  want- 
ed ;  and  is  apt  to  have  a  disagreeable  or 
burned  odor,  arising  from  the  charring  of 
the  particles  of  organic  dust,  which  are 
earned  with  the  air  over  the  too  highly 
heated  surfaces  of  the  stove  or  flues.  A 
little  aqueous  vapor,  sent  in  along  with 
the  warm  air  by  placing  a  saucer  of  water 
in  some  convenient  situation,  is  often 
effectual  in  preventing  the  disagreeable 
sensation  occasioned  by  respiring  too  dry 
an  atmosphere. 

The  common  Dutch  stove  is  an  iron 
box,  of  an  oblong  square  form,  intended 
to  stand  in  the  middle  of  a  room.  The 
air  is  admitted  to  the  fire,  through  a  small 
opening  in  the  door,  and  the  smoke  passes 
off  through  a  narrow  funnel.  -  Being  in- 
sulated, and  detached  from  the  walls  of 
tbe  room,  a  greater  part  of  the  heat  pro- 
duced by  the  combustion  is  saved,  and 
the  radiated  heat  being  thrown  into  the 
walls  of  the  stove,  they  become  hot,  and, 
in  their  turn,  radiate  neat  on  all  sides  to 
the  room.  The  conducted  heat  is  also 
received  by  successive  portions  of  the  air 
of  the  room,  which  pass  in  contact  with 
the  stove. 

The  Swedish  and  Kussian  stoves  are 
small  furnaces,  with  a  very  circuitous 
smoke  flue.  In  principle,  they  resemble 
a  common  stove,  with  a  funnel  bent  round 
and  round,  until  it  has  performed  a  great 
number  of  turns  or  revolutions,  before  it 
enters  the  chimney.  It  differs,  however, 
in  being  wholly  inclosed  in  a  large  box 
of  stone  or  brick-work,  which  is  inter- 
sected with  air- pipes.  In  operation ,  it 
communicates  heat  more  slowly,  being 
longer  in  becoming  hot,  and  also  slower 
in  becoming  cold,  than  the  common  stove. 

Kussian  stoves  are  usually  provided 
with  a  dan  per,  or  valve,  at  top,  which  is 
used  to  close  the  funnel  or  passage,  when 
the  smoke  has  ceased  to  ascend.  Its  op- 
eration, however,  is  highly  pernicious, 
since  burning  coals,  when  they  are  fully 


ignited,  always  give  out  carbonic  acid  in 
large  quantities  which  renders  the  air  of 
the  room  unfit  for  respiration. 

The  forms  of  stoves  patented,  and  in 
use  in  this  country,  are  so  numerous, 
that  it  has  been  thought  unnecessary  to  do 
more  than  advert  to  the  general  principles 
which  should  regulate  their  use. 

STOVE.  In  horticulture,  a  structure 
in  which  plants  are  cultivated  that  require 
a  considerably  higher  temperature  than 
the  open  air  in  Britain  and  similar  cli- 
mates. There  are  two  or  three  kinds  of 
stoves,  but  the  principal  are  the  dry 
stove  and  the  damp  stove.  The  dry  stove 
is  a  structure,  the  atmosphere  of  which  is 
heated  to  the  temperature  of  from  55° 
to  60°  during  winter,  in  which  are  chiefly 
cultivated  succulents;  such  as  the  differ- 
ent species  of  Ceretvs,  Cereus,  StapJielia, 
Euphorbia,  Mesembryanihemvm,  and  other 
succulents  having  similar  habits.  During 
winter  these  plants  require  very  little 
water,  and  during  summer  they  require 
intense  heat,  and  abundance  of  air  and 
water  during  fine  weather.  The  damp 
stove,  sometimes  also  called  the  bark 
stove,  requires  a  temperature  of  be- 
tween 60°  and  70°  during  winter,  with 
a  proportionate  increase  during  summer, 
accompanied,  in  both  seasons,  with  a 
degree  of  atmospherical  moisture.  This 
moisture  is  produced  partly  by  evapora- 
tion from  the  bark  bed  in  which  the 
plants  are  plunged,  but  chiefly  by  water- 
ing the  floor  of  the  house,  and  by  syring- 
ing the  plants.  During  summer  the 
plants  in  the  bark-stove  require  all  the 
light  which  an  unclouded  atmosphere 
is  capable  of  producing,  together  with 
abundance  of  air,  as  in  the  dry  stove. 
Both  stoves  are  heated  by  smoke  flues, 
or  by  hot  water  or  steam,  circulated  in 
metallic  or  other  tubes.  The  plants  cul- 
tivated in  the  moist  stove  are  exclusively 
those  of  the  tropics ;  and  those  which 
require  the  highest  degree  of  heat  are 
chiefly  Monocotyledonous  plants,  such  as 
the  Scitaminem,  which  include  the  ginger, 
plantain,  banana,  sugar  cane,  palms, 
Orchidacea ;  and  such  Dicotyledonous 
plants  as  the  bread  fruit,  the  yam,  man- 
gosteen,  and  other  East  Indian  plants. 

STRAW-HAT  MANUFACTURE.  In 
Italy  the  straw  used  for  hats  is  made  of 
rye,  which  is  sown  on  poor  land,  very 
thick,  and  it  therefore  does  not  grow  to 
above  one  half  of  its  usual  size.  The  rve 
straw  used  for  braiding  is  cut  near  the 
ground  when  the  grain  is  in  the  uiUk. 
It  is  tied  up  in  small  bundles,  the  heads 
cut  off,  and  then  it  is  dipped  in  boiling 


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CYCLOPEDIA    OF    THE    USEFUL  ARTS. 


611 


water,  and  put  out  to  dry  in  the  sun, 
taking  care  to  take  it  in  at  night,  and 
allowing  no  dew  to  get  on  it.      When 

f>roper!y  dried,  it  is  cut  into  proper 
engths,  drawn  between  the  fingers  with 
a  blunt  knife  edge  along  the  inside,  and 

is  used  either  for  fine  or  coarse  bonnets, 
as  is  desired.  The  tool  used  for  splitting 
straw  is  apiece  of  wood  five  inches  long, 
with  a  series  of  sharp  spurs  near  one  end, 
with  a  wooden  or  metal  spring  over  the 
spurs — or,   rather,    one  side  of  them — 

which  is  pressed  down  upon  the  straw  to 
keep  it  spread  flat,  while  it  is  drawn  over 
the  spurs  and  split. 

Straw  is  bleached  by  wetting  it,  and 
putting  it  into  a  tight  box  or  barrel,  with 
some  sulphur  placed  on  hot  coals  in  an 
iron  pot,  placed  on  the  bottom  of  it,  so 
as  to  allow  the  straw  to  receive  the  free 
action  of  the  sulphurous  vapor.  Two 
ounces  of  bar  sulphur  will  bleach  a  pound 
of  straw.  The  straw  must  be  kept  from 
the  sides  of  the  box,  by  laying  it  on  strips 
of  wood  running  across  the  box  or  cask. 
It  should  not  be  taken  outof  the  sulphur 
box  in  less  time  than  four  hours.  Old 
straw,  leghorn,  or  palm-leaf  hats  or  bon- 
nets, may  be  whitened  in  this  way,  if 
they  are  thoroughly  washed  with  a  brush 
or  spOnge  in  soap-suds,  before  smoking. 
Straw  must  always  be  wet  when  it  is 
braided,  to  prevent  its  breaking.  The 
braiding  and  platting  of  straw  is  accom- 
plished, in  this  country,  by  a  straw  plat- 
ting machine,  which  is  capable  of  braid- 
ing six  plats.  When  the  straw  hats  arc 
dry,  after  being  cleaned,  they  are  sized 
with  size  made  of  clean  parchment  par- 
ings boiled  in  water,  and  then  hung  out 
to  dry  ;  and  are  afterwards  pressed' with 
clean  damp  cloths  and  hot  irons,  on 
blocks  which  fit  them  to  the  desired 
shape. 

The  mode  of  preparing  the  Tuscany  or 
Italian  straw  is  different  from  that  made 
of  rye,  and  is  commenced  by  pulling  the 
bearded  wheat  while  the  ear  is  in  a  soft 
milky  state.  The  straw  is  spread  out 
thinly  upon  the  ground  in  fine  hot 
weather,  lor  three  or  four  days,  to  dry  the 
sap  ;  it  is  then  tied  up  in  bundles  and 
stacked,  for  the  purpose  of  enabling  the 
heat  of  the  mow  to  drive  off  any  remain- 
ing moisture.  It  is  important  to  keep  the 
ends  of  the  straw  air-tight,  in  order  to 
retain  the  pith,  and  prevent  its  gummy 
particles  from  passing  off  by  evapora- 
tion. 

After  the  straw  has  been  exposed  about 
a  month,  it  is  removed  to  a  meadow  and 
spread  out,  that  the  dew  may  act  upon 


it,  together  with  the  sun  and  air,  and 
promote  the  bleaching.  The  first  pro- 
cess of  bleaching  being  complete,  the 
lower  joint  and  root  is  pulled  from  the 
straw,  leaving  the  upper  part  fit  for  use, 
which  is  then  sorted  according  to 
qualities  ;  and  after  being  submitted  to 
the  action  of  steam,  for  the  purpose  of 
extracting  its  color,  and  then  to  a  fumi- 
gation of  sulphur,  to  complete  the  bleach- 
ing, the  straws  are  in  a  condition  to  be 
platted  or  woven  into  hats  and  bonnets, 
and  are  in  that  state  imported  in  bundles, 
the  dried  ears  of  the  wheat  being  still  on 
the  straw. 

Straw  may  be  bleached  by  a  solution  of 
chloride  of  lime.  The  straw,  after  being 
aired  and  softened  by  spreading  it  upon 
the  grass  for  a  night,  is  ready  to  be  split, 
preparatory  to  dyeing.  Blue  is  given  by 
a  boiling-hot  solution  of  indigo  in  sul- 
phuric acid,  called  Saxon  blue,  diluted 
to  the  desired  shade ;  yellow,  by  decoc- 
tion of  turmeric;  red,  'by  boiling  hanks 
of  coarse  scarlet  wool  in  a  bath  of  weak 
alum  water,  containing  the  straw ;  or 
directly,  by  cochineal,  salt  of  tin,  and 
tartar/  Brazil  wood  and  archil  are  also 
employed  for  dyeing  straw. 

STRENGTH.  The  power  exerted  by 
an  animal  or  machine  in  overcoming  re- 
sistance. That  of  the  horse  is  used  as  a 
standard  ;  it  certainly  is  the  most  useful, 
and  that  whose  labor  is  susceptible  of  the 
most  numerous  and  varied  applications. 
It  is  therefore  very  important  to  ascertain 
his  average  force ;  and  accordingly  a  great 
number  of  estimates  have  been  published, 
both  of  the  amount  of  labor  he  is  capable 
of  performing,  and  of  his  absolute  mus- 
cular power/  For  the  purpose  of  deter- 
mining the  latter,  the  dynamometer  may 
be  conveniently  used;  but  as  the  action 
of  the  animal  is  very  quickly  reduced  by 
continued  exertion,  it  is  more  usual  to 
estimate  it  according  to  the  amount  of 
daily  labor  performed.  Desaguliers  and 
Smeaton  estimate  the  strength  of  a  horse 
as  equivalent  to  that  of  five  men;  the 
French  authors  have  commonly  stated  it 
as  equal  to  that  of  seven  men ;  and  Schulze 
makes  it  equal  to  that  of  fourteen  men  in 
drawing  horizontally.  According  to  Des- 
aguliers, a  horse's  power  is  equivalent  to 
44,000  lbs.  raised  1  foot  high  in  one  min- 
ute ;  Smeaton  makes  this  number  22,916; 
Hachette  28,000  ;  and  Watt  33,000.  This 
last  estimate  is  what  is  commonly  under- 
stood by  the  term  horse  power  as  applied 
to  steam  engines. 

The  quantity  of  action  which  a  horse 
can  exert  diminishes  as  the  duration  of 


612 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[STR 


the  labor  is  prolonged.  Tredgold  gives 
the  following  table,  showing  the  average 
maximum  velocity  with  which  a  horse 
unloaded  can  travel,  according  to  the 
number  of  hours  per  day  : 


Time  of 

Greatest  Velo- 

Time of 

Greatest  Velo- 

March, in 

city  per  Hour, 

j    Mnr-h,  in 

city  per  Hour, 

Hours. 

in  Miles. 

|       Huurs. 

in  Miles. 

1 

14-7 

6 

60 

2 

10-4 

7 

55 

8 

85 

8 

5-2 

4 

73 

9 

4-9 

5 

66 

10 

46 

The  useful  effect  a  horse  is  capable  of 
producing,  depends  much  on  the  manner 
in  which  his  strength  is  applied.  One  of 
the  best  modes  is  to  mane  him  draw  a 
loaded  carriage.  The  carriers  in  Scot- 
land usually  transport  in  a  single-horse 
cart,  weighing  about  7  cwt.,  the  load  of  a 
ton,  and  travel  at  the  rate  of  22  miles  per 
day.  Neglecting  the  weight  of  the  ani- 
mal and  of  the  cart,  and  supposing  the 
journey  to  be  accomplished  in  10  hours, 
the  useful  effect  reduced  to  dynamic 
units  (1000  lbs.  one  foot  in  one  minute) 
is  260,198  dynamic  units. 

Napier  gives  the  following  results  :  A 
horse,  drawing  in  a  cart  a  load  of  1540 
lbs.,  (700  kilogrammes,)  travels  at  the 
rate  of  216*  feet  per  minute,  during  10 
hours  per  day.  Here  the  useful  effect  is 
200,046. 

A  horse  harnessed  in  a  coach,  and 
drawing  a  load  of  770  lbs.  avoirdupois, 
goes  at  a  trot  at  the  rate  of  433  feet  per 
minute,  during  4*  hours  per  day.  The 
useful  effect  is  consequently  90,020. 

A  horse  carrying  on  his  back  a  load  of 
264  lbs.  can  travel  at  the  rate  of  2161  feet 
per  minute,  10  hours  a  day.  The  useful 
effect  is  34,294  dynamic  units.  Going  at 
a  trot  with  double  the  velocity,  during  7 
hours  a  clay,  and  carrying  a  load  of  176 
lbs.,  the  useful  effect  is  32,007. 

A  horse  harnessed  in  a  mill,  going  at  a 
pace  of  195  feet  per  minute,  and  exercis- 
ing a  force  equal  to  a  pressure  of  99  lbs., 
during  8  hours  a  day,  produces  a  useful 
effect^  represented  by  9266  dynamic 
units. 

On  the  strength  of  mules,  oxen,  and 
the  other  animals  employed  in  industry, 
there  are  few  correct  observations.  The 
following  are  the  principal  results  :  Tak- 
ing the  useful  effect  of  the  daily  labor  of 
a  man  according  to  Coulomb's  estimate 
as  unity,  then  the  comparative  effects  of 
the  labor  of  some  of  the  other  animals 


applied  in  the  same   manner  are  thus 
estimated : 

For  carrying  loads  in  a  horizontal 
plane — 

Strength  of  a  man 1     (Coulomb.) 

"        of  a  horse 48  (Brunacci.) 

"        of  a  horse 61  (  Wesermann.) 

"       of  ahorse 76  (Brunacci) 

For  transporting  burdens  with  a  wheel 
carriage — 

Man  with  a  barrow 1     Coulomb.) 

Horse  in  a  four  wheel  wagon.. 17  5  (Weserm.) 

Horse  with  a  cart 24  3  (Brunacci.) 

Mule  with  a  cart 233  (Brunacci.) 

Ox  with  a  cart 122  (Brunacci.  ) 

The  above  comparisons  are  probably 
nearer  the  truth  than  the  following,  which 
are  usually  quoted  from  Hassenfratz 
(Encyclopedie  Methodique) : 

In  carrying  loads  on  a  horizontal 
plane — 

Strength  of  a  man 1 

"        of  a  horse 8 

«*       ofamule 8 

"         oi  an  ;i>s 4 

u        of  a  camel 31 

"        of  a  dromedary 25 

"        of  an  elephant ...147 

"        of  a  dog * 

"        of  a  reindeer 3 

In  drawing  a  weight  along  a  horizontal 
plane — 

Strength  of  a  man 1 

"  of  a  horse 7 

"  ofamule    7 

"  of  an  ass 2 

"  of  an  ox 4  to  7 

"  ofadog 06 

"  of  a  reindeer 0*2 

STEENGTH  OF  MATEEIALS.  The 
force  with  which  a  solid  body  resists  an 
effort  to  separate  its  particles,  or  destroy 
their  aggregation,  can  only  become 
known  from  experiment ;  nevertheless,  if 
we  assume  an  hypothesis  to  represent  the 
manner  in  which  the  elementary  particles 
are  arranged  and  cohere,  general  formulae 
may  be  deduced,  which  will  represent  the 
comparative  strength  of  bodies  of  differ- 
ent forms  and  dimensions,  or  submitted 
to  the  action  of  forces  applied  indifferent 
manners,  and  will  consequently  bo  of 
great  use  in  practical  mechanics. 

There  are  four  different  ways  in  which 
the  strength  of  a  solid  body  may  be  exerted: 
first,  in  resisting  a  longitudinal  tension, 
or  force  tending  to  tear  it  asunder ;  se- 
condly, in  resisting  a  force  tending  to 
break  the  body  by  a  transverse  strain ; 
thirdly,  in  resisting  compression,  or  a 


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CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


613 


force  tending  to  crush  the  body ;  and 
fourthly,  in  resisting  a  force  tending  to 
wrench  it  asunder  by  torsion.  We  shall 
consider  these  separately. 

1.  Longitudinal  Tension. — The  resist- 
ance opposed  by  a  solid  body  to  a  longi- 
tudinal strain  is  usually  termed  the  ab- 
solute strength,  or  force  of  direct  cohe- 
sion, of  the  body.  Two  points  may  be 
proposed  for  investigation  :  first,  to  de- 
termine the  quantity  by  which  a  body 
of  a  given  length  is  stretched  or  elongat- 
ed under  the  action  of  a  given  force  or 
weight ;  and  secondly,  the  effect  required 
to  separate  the  parts  or  produce  rupture. 
Experiments  have  usually  been  directed 
to  the  last  of  these  only,  but  the  first 
may  be  determined  indirectly  from  ex- 
periments on  flexure.  In  bodies  of  a 
fibrous  structure,  as  the  woods,  the  co- 
he  ive  force  differs  greatly,  according  as 
the  effect  is  applied  in  the  direction  of  the 
fibres,  or  at  right  angles  to  it.  When 
the  strain  is  exerted  in  the  direction  of 
the  fibres,  the  cohesive  force  obviously 
depends  on  two  circumstances  only — the 
strength  of  each  fibre,  and  their  number ; 
and,  in  general,  in  bodies  of  the  same 
substance  and  structure,  the  strength  is 
proportional  to  the  transverse  area  of  the 
body,  and  to  a  certain  constant  which 
must  be  determined  by  experiment. 

Although  the  longitudinal  tension  is, 
with  respect  to  mechanical  action,  the 
simplest  of  all  the  strains  to  which  a 
solid  body  can  bo  subjected,  it  is  the 
most  difficult  to  submit  to  experiment, 
by  reason  of  the  enormous  forces  required 
to  produce  rupture,  and,  in  the  case  of 
fibrous  bodies,  the  difficulty  of  applying 
those  forces  in  the  direct  line  of  the 
fibres.  If  the  fibres  are  not  all  subjected 
to  the  same  strain,  it  is  obvious  that  the 
direct  cohesion  will  bo  estimated  at  less 
than  its  real  value;  and,  as  Mr.  Barlow 
remarks,  it  is  probably  owing  to  this  cir- 
cumstance that  so  little  agreement  is 
found  in  the  results  of  experiments. 

2.  Transverse  Strength. — When  a  body 
suffers  a  transverse  strain,  the  mechani- 
cal action  which  takes  place  among  the 
particles  is  of  a  more  complicated  nature. 
Galileo  was  the  first  who  attempted  to 
give  a  rational  explanation  of  this  action, 
and  to  submit  the  strength  of  the  mate- 
rials used  in  the  mechanical  arts  to  the 
measures  of  geometry  and  arithmetic. 
He  assumed  that  all  solid  bodies  are  com- 
posed of  numerous  small  parallel  fibres, 
perfectly  inflexible  and  inextensible  ;  and 
that  when  they  break,  the  several  fibres 
give  way  iu  succession,  the  body  turning 


on  the  last,  which  give  way  as  on  a  hinge, 
and  the  strain  on  each  fibre,  previous  to 
the  rupture,  being  proportional  to  its 
distance  from  the  quiescent  fibres. 

From  the  table  of  data  given  by  Bar- 
low the  following  mean  results  of  experi- 
ments (on  beams  supported  at  both  ends), 
made  in  the  dock-yard  at  Woolwich,  for 
determining  the  elasticity  and  strength 
of  various  species  of  timber,  are  ex- 
tracted : 


Description  of  Wood. 

Elasticity. 
tp/3 

Stren^ 

VZhbdz 

4bd* 

301800 
211200 
109200 
181400 
208600 
205(300 
1G9200 
87480 
153200 
273900 
166100 
108700 
131600 
18-2200 

2462 

2*221 

English  Oak 

Ditto,  another  spec. 

Canadian  Oak 

Ash 

1181 
1672 
1766 
2026 

1556 

Elm 

1013 

Pitch  Pine 

New-England  Fir.. 
Rica  Fir 

1632 
1102 
1108 

Mar  Forest  Fir 

1262 
1149 

Norway  Spar 

1474 

From  the  mean  of  a  number  of  experi- 
ments by  Tredgold,  the  values  of  E  and 
S,  for  rectangular  cast  iron  bars,  were 
found  to  be  E=2254000,  S=7620. 

Resistance  of  bodies  to  forces  tending  to 
crush  them. — The  resistance  of  a  body  to 
a  crushing  force  might  be  supposed,  a 
priori,  to  follow  the  same  law  as  the  ab- 
solute force  of  cohesion,  and,  consequent- 
ly, to  depend  only  upon  the  area  of  the 
section  and  the  force  of  aggregation  of 
the  particles.  It  is  found,  however,  by 
experiment,  that  the  thickness  of  the 
body  (or  length,  if  the  force  is  applied 
endwise),  has  an  important  influence  on 
the  amount  of  pressure  it  is  capable  of 
bearing.  Very  thin  plates  are  readily 
crushed;  and  the  resistance  appears  to 
increase  with  the  thickness  up  to  a  cer- 
tain maximum,  after  which  it  diminishes. 
The  theory  of  the  resistance  of  pillars, 
which  is  of  great  importance  on  account 
of  its  application  to  architectural  pur- 
poses, was  investigated  by  Euler;  and, 
according  to  the  hypothesis  adopted  by 
him,  the  strength  varies  directly  as  the 
fourth  power  of  the  diameter  or  side,  and 
inversely  as  the  square  of  the  length. 
This  is  confirmed  by  the  recent  experi- 
ments of  Mr.  Hodgkinson,  in  respect  of 
pillars  of  wrought  iron  or  timber;  but  in 


614 


CYCLOPEDIA    OF    THE    USEFUL    ARTS 


[sub 


the  case  of  pillars  of  cast  iron,  the  powers  i 
of  the  diameter  and  length  were  some-  J 
what  different.    Mr.  Hodgkinson  found  i 
from  a  mean  of  experiments,  that  a  solid,  ! 
uniform  pillar  of  cast  iron,  whose  trans-  i 
verse  section  is  one  square  inch,  is  de-  j 
stroyed   by  a  weight  of  98922  lbs.,  or  | 
44-16  tons.     Assuming  this  as  a  unit  of  j 
measure,  he  gives  the  following  formula  j 
(as   representing    his   experiments),    in  j 
which   s  is  the  strength  or  weight  in 
lbs.  that  would  crush  the  pillar,   d  the 
diameter,  and  I  the  length,  viz.,  s=98922 
Y.d  3-55 -j.  j i-7,      This   formula  applies   to 
pillars  of  which  the  lengths  are  twenty- 
five  times  the  diameter  and  upwards,  and 
which    are   perfectly   flat    at    the   ends. 
"When  the  ends  of  a  pillar  are  rounded, 
so  that  the  load  bears  only  on  the  middle 
fibres,  the  strength  is  greatly  reduced. 
In  pillars  whose  length  is  thirty  times  the 
diameter,  or  upwards,  Mr.  Hodgkinson 
found  the  strength  of  those  with  flat  ends 
to  be  about  three  times  greater  than  the 
strength  of  others  of  the  same  dimen- 
sions with  round  ends,  the  mean  ratio 
being  3-167.    In  shorter  pillars  the  ratio 
was  not  constant.     The  strength  of  a 
pillar  is  slightly  increased  by  placing  disks 
on  the  ends  to  increase  the  bearings. 

STRONTI  A,  one  of  the  alkaline  earths, 
of  which  strontium  is  the  metallic  basis, 
occurs  in  a  crystalline  state,  as  a  carbon- 
ate, in  lead  mines.  The  sulphate  is  found 
crystallized  in  several  parts  of  the  world; 
but  strontitic  minerals  are  rather  rare. 
The  pure  earth  is  prepared,  like  baryta, 
from  the  carbonate  or  the  sulphate.  It  is 
a  grayish-white  powder,  infusible  in  the 
furnace,  of  a  specific  gravity  approaching 
baryta,  having  an  acrid,  burning  taste. 
It  becomes  hot  when  moistened,  and 
slakes  into  a  pulverulent  hydrate,  dis- 
solves in  150  parts  of  water  at  60°,  and 
in  much  less  at  the  boiling  point,  forming 
an  alkaline  solution  called  strontia  water, 
which  deposits  crystals  in  four-sided 
tables  as  it  cools.  These  contain  68  per 
cent,  of  water,  are  soluble  in  52  parts  of 
water  at  60°,  and  in  about  2  parts  of  boil- 
ing water ;  when  heated  they  part  with 
53  parts  of  water,  but  retain  the  other  15 
parts  at  a  red  heat.  The  dry  earth  con- 
sists of  84-55  of  base,  and  15-45  of  oxy- 
gen. It  is  readily  distinguished  from 
baryta,  by  its  inferior  solubility,  and  by 
its  soluble  salts  giving  a  red"  tinge  to 
flame,  while  those  of  baryta  give  a  yellow 
tinge.  Fluosilicic  acid  and  iodate  of  soda 
precipitate  the  salts  of  the  latter  earth, 
but  not  those  of  the  former.  The  com- 
pounds of  strontia  are  not  poisonous,  like 


those  of  baryta.  The  only  prepara- 
tion of  strontia  used  in  the  arts  is  the 
Nitrate.     (See  Pykotechny.) 

STRYCHNIA.  A  poisonous  vegetable 
alkaloid,  discovered  in  1818  by  Pelletier 
and  Caventou  in  the  seed  of  the  Strych- 
nos  ignatia  and  Nux  vomica,  and  also  in 
the  upas  poison.  It  is  almost  insoluble 
in  water,  but  very  soluble  in  boiling  al- 
cohol, from  which  it  is  deposited  by  care- 
ful evaporation  in  small  white  crystals. 
It  is  so  virulently  poisonous,  that  half  a 
grain  blown  into  the  throat  of  a  rabbit 
occasioned  death  in  five  minutes ;  its 
operation  is  accompanied  by  lock-jaw 
and  other  tetanic  affections.  The  chem- 
ical equivalent  of  strychnia  is  about  238. 
It  probably  consists  of  SO  atoms  of  car- 
bon, 16  hydrogen,  3  oxygen,  and  1  nitro- 
gen. 

STUBBLE.  The  root  ends  of  stalks  of 
grain  left  in  the  field  standing  as  they 
grow  after  the  grain  has  been  reaped  by 
the  sickle  or  scythe.  In  some  parts  of 
the  country  only  a  small  portion  of  the 
straw  is  cut  off  with  the  ears,  and  the 
stubble  in  that  case  is  a  foot  or  eighteen 
inches  in  length  ;  but  in  others  the  grain 
is  cut  as  close  to  the  surface  as  possible, 
in  which  case  the  stubble  is  quite  short. 
In  general,  long  stubble  is  objectionable, 
as  the  straw  is  in  this  case  left  waste  in 
the  field,  which  might  have  been  carried 
home  and  rotted  into  manure.  It  may, 
however,  be  turned  into  the  ground. 

STUCCO.  In  architecture,  a  term  ap- 
plied to  many  sorts  of  calcareous  ce- 
ments. The  sense  in  which  it  is  most 
commonly  used  in  this  country  is  to  de- 
note the  third  coat  of  three-coat  plaster, 
consisting  of  fine  lime  and  sand.  The 
better  sort  is  hand-floated  twice  and  well 
trowelled.  There  is  a  species  called  bas- 
tard stucco,  in  which  a  small  portion  of 
hair  is  used.  Rough  stucco  is  merely 
floated  and  brushed  with  water,  but  the 
best  is  trowelled  stucco. 

SUBERIC  ACID.  An  acid  substance 
into  which  cork  is  converted  by  the  long- 
continued  action  of  nitric  acid. 

SUBERIN.  A  name  given  by  Chev- 
reul  to  the  cellular  tissue  of  cork  after  the 
various  soluble  matters  have  been  re- 
moved by  the  action  of  water  and  alcohol. 

SUBLIMATION.  A  process  by  which 
solids  are  by  the  aid  of  heat  converted 
into  vapor,  which  is  again  condensed, 
and  often  in  the  crystalline  form.  This 
operation  is  frequently  resorted  to  for 
the  purpose  of  purifying  various  chem- 
ical products,  and  separating  them  from 
substances  which  are  less  volatile. 


bug] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


SUBSTANTIVE  COLORS,  are  those 
which,  in  the  process  of  dyeing,  remain 
fixed  or  permanent  without  the  interven- 
tion of  other  substances  ;  they  are  oppos- 
ed to  adjective  colors,  which  require  to  be 
fixed  by  certain  intermedia,  or  substances 
which  have  a  joint  affinity  for  the  color- 
ing matter  and  the  material  to  be  dyed. 
(See  Dyeing  and  Mordant.) 

SUBSTRATUM.  A  stratum  lying  un- 
der another.  The  term  subsoil  is  gener- 
ally applied  to  the  matters  which  inter- 
vene between  the  surface  soils  and  the 
rocks  on  which  they  rest ;  thus  clay  is  the 
common  substratum  or  subsoil  of  gravel. 

SUGAR,  is  the  sweet  constituent  of 
vegetable  and  animal  products.  It  may 
be  distinguished  into  two  principal  spe- 
cies. The  first,  which  occurs  in  the  su- 
gar-cane, the  beet-root,  and  the  maple, 
crystallizes  in  oblique  four-sided  prisms, 
terminated  by  two-sided  summits  ;  it  has 
a  sweetening  power  which  may  be  repre- 
sented by  100  ;  and  in  circumpolarization 
it  bends  the  luminous  rays  to  the  right. 
The  second  occurs  ready  formed  in  ripe 
prapes  and  other  fruits ;  it  is  also  pro- 
duced by  treating  starch  with  diastase  or 
sulphuric  acid.  This  species  forms  cauli- 
flower concretions,  but  not  true  crystals  ; 
it  has  a  sweetening  power  which  may  be 
represented  by  60,  and  in  circumpolari- 
zation it  bends  the  rays  to  the  left.  Be- 
sides these  two  principal  kinds  of  sugar, 
some  others  are  distinguished  by  chem- 
ists ;  as  the  sugar  of  milk,  of  manna,  of 
certain  mushrooms,  of  liquorice-root,  and 
that  obtained  from  saw-clust  and  glue  by 
the  action  of  sulphuric  acid;  but  they 
have  no  importance  in  a  manufacturing 
point  of  view.  - 

Sugar,  extracted  either  from  the  cane, 
the  beet,  or  the  maple,  is  identical  in  its 
properties  and  composition,  when  refined 
to  the  same  pitch  of  purity  ;  only  that  of 
the  beet  seems  to  surpass  the  other  two 
in  cohesive  force,  since  larger  and  firmer 
crystals  of  it  are  obtained  from  a  clarified 
solution  of  equal  density.  It  contains 
5-3  per  cent,  of  combined  water,  which 
can  be  separated  only  by  uniting  it  with 
oxide  of  lead,  into  what  has  been  called  a 
saccharate  ;  made  by  mixing  syrup  with 
finely  ground  litharge,  and  evaporating 
the  mixture  to  dryness  upon  a  steam- 
bath.*  When  sugar  is  exposed  to  a  heat 
of  400°  F.,  it  melts  into  a  brown  pasty 
mass,  but  still  retains  its  water  of  compo- 
sition. Sugar  thus  fused  is  no  longer 
capable  of  crystallization,  and  is  called 
caramel  by  th"e  French.  It  is  used  for 
coloring  liquors.      Indeed,   sugar   is  so 


susceptible  of  change  by  heat,  that  if  a 
colorless  solution  of  it  be  exposed  for 
some  time  to  the  temperature  of  boiling 
water,  it  becomes  brown  and  partially 
uncrystallizable.  Acids  exercise  such  an 
injurious  influence  upon  sugar,  that  after 
remaining  in  contact  with  it  for  a  little 
while,  though  they  be  rendered  thor- 
oughly neutral,  a  great  part  of  the  sugar 
will  refuse  to  crystallize.  Thus,  if  three 
parts  of  oxalic  or  tartaric  acid  be  added 
to  sugar  in  solution,  no  crystals  of  sugar 
can  be  obtained  by  evaporation,  even 
though  the  acids  be  neutralized  by  chalk 
or  carbonate  of  lime.  By  boiling  cane 
sugar  with  dilute  sulphuric  acid,  it  is 
changed  into  starch  sugar.  Manufactu- 
rers of  sugar  should  be,  therefore,  parti- 
cularly watchful  against  every  acidulous 
taint  or  impregnation.  Nitric  acid  con^ 
verts  sugar  into  oxalic  and  malic  acids. 
"When  one  piece  of  lump  sugar  is  rubbed 
against  another  in  the  dark,  a  phospho- 
rescent light  is  emitted. 

Sugar  is  soluble  in  all  proportions  in 
water ;  but  it  takes  four  parts  of  spirits 
of  wine,  of  spec.  grav.  0-830,  and  eighty 
of  absolute  alcohol,  to  dissolve  it,  both 
being  at  a  boiling  temperature.  As  the 
alcohol  cools,  it  deposits  the  sugar  in 
small  crystals.  Caramelized  and  uncrys- 
tallizable sugar  dissolve  readily  in  alco- 
hol. Pure  sugar  is  unchangeable  in  the 
air,  even  when  dissolved  in  a  good  deal 
of  water,  if  the  solution  be  kept  covered 
and  in  the  dark ;  but  with  a  very  small  ad- 
dition of  gluten,  the  solution  soon  begins 
to  ferment,  whereby  the  sugar  is  decom- 
posed into  alcohol  and  carbonic  acid,  and 
ultimately  into  acetic  acid. 

SUGAR,  MANUFACTURE  OF.  The 
great  commercial  demand  for  sugar  is 
almost  exclusively  supplied  from  the  su- 
gar cane  (Arun'do  saccharifera),  which 
contains  it  in  greater  quantity  and  purity 
than  any  other  plant,  and  consequently 
affords  the  greatest  facilities  for  its  ex- 
traction. A  large  quantity  of  sugar  is 
contained  in  the  sap  of  the  American 
maple  (Acer  saccJiarinum),  and  in  the 
juice  of  the  beet-root  (Beta  vulgaris). 
from  both  of  which  it  may  be  economi- 
cally obtained  ;  it  has  also  been  extract- 
ed from  grapes  or  raisins,  and,  as  is  well 
known,  is  contained  abundantly  in  many 
ripe  fruits  and  esculent  vegetables.  It  is, 
however,  in  these,  seldom  so  pure  or  in 
such  quantity  as  to  admit  of  ready  sepa- 
ration. 

Sugar  is  a  crop,  which,  as  made  from 
the  cane,  is  almost  confined  to  Louisiana, 
in  this  country.    The  return  of  the  crop 


616 


CTCLOPEDIA    OF    THE    USEFUL    ARTS. 


[suo 


of  1346,  was  about  140,000  hogsheads.  In 
the  year  1848,  the  growth  being  larger, 
it  was  estimated  at  240,000— which  at  "the 
rate  of  50  dollars  a  hogshead,  would  give 
the  sum  of  12,000,000  dollars,  the  value 
of  a  single  product  of  23  parishes  in  that 
State.  The  cultivation  of  this  plant  is 
extending  in  Georgia,  Alabama,  and  Flo- 
rida. Texas,  however,  will  be  the  great-  ! 
est  rival  of  Louisiana  in  the  cultivation. 

The   steady  advance   in  improvement 
of  Louisiana,  affords  encouragement  to  I 
believe,  that  the  time  may  not  be  far  dis- 
tant, when  this  State,  aided  by  Florida 
and  Texas,  will  be  able  to  furnish  enough  j 
to  meet  all  the  demands  for  consumption  | 
of  this  article  in  the  United  States.    This 
would  be  a  very  desirable  consummation, 
not  merely  on  account  of  the  growing  ! 
prosperity  of  this  State,  but  as  occasion-  | 
mg  still  increased  exchange  of  products 
from  other  States. 

The  following,  taken  from  the  New 
Orleans  Price  Current,  of  September  1, 
1847,  as  the  amount  of  the  crops  of  that 
State  for  many  years  past : 

Crop  of  1828 88,000  hhds. 

"  1829 48,000    " 

"  1832 70,000     " 

"  1833 75,000     " 

"  1834  100,000     " 

"  1835 30,000     " 

"  1836 70,000     " 

"  1837 65,000     " 

"  1838 70,000     « 

"  1839 115,000     « 

"  1840 87,000     « 

"  1841  90,000     " 

"  1842 140,000     " 

"  1843 100,000     " 

■  1844  200,000     " 

"  1845 186,000     " 

"  1846 200,000     " 

"  1847  240,000     " 

The  production  and  consumption  of 
sugar  is  large.  In  1844,  the  whole  amount 
produced  from  all  the  sugar-growing 
countries  in  the  world  was  set  down  at 
778,000  tons,  of  which  200,000  was  sup- 
plied by  Cuba  alone.  It  is  probable  that 
by  this  time,  therefore,  it  can  scarcely  be 
less  than  850  to  900,000  tons,  if  we  in- 
clude beet  and  maple  sugar.  It  is  esti- 
mated that  Great  I3ritain  consumes  as 
much  as  250,000  tons,  the  rest  of  Europe 
450,000,  the  United  States  150  to  160,000 
tons,  or  more ;  Canada  and  the  other 
British  Colonies,  25,000  tons. 

The  amount  of  beet-root  sugar  made  in 
France  in  1846-1847,  was  estimated  at 
107,190,110  pounds,  being  an  increase  of 
26,596,432  pounds  on  the  quantity  manu- 
factured the  previous  year.  This  article 
shows  the  importance  of  perseverance  in 


such  experiments  as  hold  out  the  proba- 
bility of  success.  It  is  well  known,  as  a 
fact  of  history,  that  the  origin  of  this 
manufacture  as  a  national  one,  sprung 
from  the  necessities  of  the  French  people, 
when  in  their  wars,  they  were  cut  off 
from  the  usual  supplies  of  cane  sugar  by 
the  West  Indies.  It  is  not  less,  too,  a 
matter  of  record,  how  great  was  the  ridi- 
cule cast  upon  the  Emperor  Napoleon  for 
his  efforts  by  way  of  encouragement  to 
this  business. 

Five  different  kinds  of  cane  are  culti- 
vated in  Louisiana — Bourbon,  green-rib- 
bon, red-ribbon,  Otaheite,  and  Creole. 
The  two  first  are  the  most  extensively 
cultivated.  The  cane  is  planted  in  fall, 
sometimes  in  October,  in  rows  from  five 
to  eight  feet  apart,  and  reaches  its  full 
growth  in  nine  months.  It  grows  so 
luxuriant  that  the  rays  of  the  sun  can- 
not penetrate  it.  Previous  to  panting, 
the  soil  is  ploughed,  harrowed,  and  the 
furrow  opened  with  a  double  mould- 
board  plough.  Cane  slips  are  then  laid 
in  straight  lines  three  thick,  and  over- 
lapping. They  are  then  covered  four 
or  six  inches  with  earth,  as  a  protection 
from  frost. 

The  Mississippi  lands  on  which  the 
cane  grows  is  aimost  inexhaustible,  re- 
quiring no  manure  for  the  present  but 
only  to  be  ploughed  deeper.  It  is  found, 
however,  advantageous  to  plough  in  the 
tops  and  other  reluse  matter  of  the  cane. 
On  this  point,  Mr.  Benjamin,  writing  in 
De  Bow's  Review,  says : 

"  When  the  cane  is  cut  in  the  fall,  a 
large  portion  of  the  produce  of  the  soil 
remains  on  the  field,  as  is  well  known, 
in  the  tops  and  leaves  of  the  cane,  the 
ripe  portion  alone  of  the  stalk  being  con- 
veyed to  the  mill.  This  is  called  the 
trash,  and  is  placed  on  the  stubble  to  as- 
sist in  protecting  from  the  frost  that  part 
of  the  cane  which  remains  under  ground, 
and  from  which  the  rattoous  shoot  up 
the  ensuing  season.  As  soon  in  the 
spring  as  danger  of  frost  is  no  longer  ap- 
prehended, the  trash  is  raked  off  the 
rows  of  stubble  to  allow  access  to  the 
sun  and  air;  and  on  nearly  all  planta- 
tions this  trash,  which  is  a  useful  and 
fertilizing  manure,  is  burnt  up,  instead 
of  being  returned  to  the  earth.  One 
cause  of  the  difficulty  of  making  use  of 
this  trash  as  manure,  was  the  narrow- 
ness of  the  space  between  the  rows  under 
the  old  system  of  planting,  which  left  so 
little  room  as  to  make  the  operation  of 
ploughing  in  the  trash  difficult  and  la- 
borious; but  where  the  rows  are  eight 


sug] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


617 


feet  apart,  the  task  is  easy.  Independ- 
ently of  the  considerations  to  which  I 
snail  presently  advert,  and  which  derive 
their  force  from  the  chemical  constitu- 
tion of  the  cane,  it  is  difficult  for  a  person 
who  has  not  witnessed  the  results  to 
form  an  adequate  idea  of  the  improve- 
ment to  a  soil  that  is  naturally  at  all  stiff 
or  clayey,  from  the  mere  mechanical  sub- 
division of  its  particles  attendant  on  the 
decay  of  the  large  quantity  of  this  trash 
left  annually  in  the  fields.  This  system 
was  first  put  into  operation  last  year  on 
the  plantation  of  which  I  am  part  owner." 

When  the  canes  are  ripe,  they  are  cut 
and  sent  to  the  crushing-mill  to  separate 
the  juice. 

The  mills  used  for  grinding  the  cane 
are  generally  placed  10  to  12  feet  from 
the  ground,  in  order  to  give  sufficient 
fall  for  the  juice  to  flow  into  the  juice- 
boxes,  and  from  them  into  the  kettles. 

The  mills  consist  mostly  of  three  iron 
rollers,  from  25  to  28  inches  in  diameter, 
and  from  4  to  5i  feet  long. 

Tito  following  cut  is  an  illustration  of 
a  horizontal  sugar-mill. 


The  thickness  of  the  shell  of  the  rollers, 
in  those  mills  constructed  by  Leeds  & 
Co.,  New  Orleans,  varies  from  2\  inches 
to  3  inches,  according  to  size  ;  the  depth 
of  the  eye  of  the  roller  is  12  inches  in  all 
these  mills.  The  shafts  are  of  wrought 
iron.  The  journals  vary  in  size  from  7i 
to  8*  inches  in  diameter.  The  boxes  in 
which  the  journals  revolve  are  of  brass, 
lined  with  "Babbitt's  anti-attrition  me- 
tal." The  return  plats,  about  which 
there  is  a  great  difference  of  opinion  re- 
specting their  proper  position,  are  placed 
from  1  to  2  inches  below  the  top  roller. 
The  cane  carrier  is  from  50  to  90  feet  in 


length,  according  to  the  height  at  which 
the  mill  is  placed. 

Planters  who  pay  attention  to  the  set- 
ting of  the  rollers  and  the  feeding  of  the 
cane  carrier,  obtain  66  per  cent,  of  juice  ; 
yet  the  usual  amount  obtained,  probably, 
does  not  exceed  52  per  cent.  W  ray  re- 
commends "the  first  under  roller  to  be 
adjusted  exactly  five-sixteenths  of  an 
inch  from  the  main  or  upper  roller,  and 
the  second  under  roller  just  one-tenth  of 
an  inch  from  the  upper  roller." 

The  juice  so  obtained,  is  carefully  eva- 
porated till  it  has  acquired  the  proper 
consistency  for  crystallizing ;  lime  water 
is  added  during  this  operation,  to  neu- 
tralize any  free  acid,  and  to  facilitate  the 
separation  of  certain  vegetable  matters, 
which,  in  consequence  of  the  action  of 
the  lime,  rise  more  readily  to  the  sur- 
face, and  admit  of  being  skimmed  off. 
When  duly  concentrated,  the  syrnp  is 
run  off  into  shallow  wooden  coolers, 
where  it  concretes ;  it  is  then  put  into 
barrels  with  holes  in  the  bottom,  through 
which  a  quantity  of  treacle  or  molasses 
gradually  drips,  and  the  remaining  sugar 
acquires  the  granular  crystalline  state ;  it 
is  packed  into  hogsheads,  and  comes  to 
us  under  the  name  of  raw  or  muscovado 
sugar. 

The  following  is  a  sketch  of  the  pro- 
cess by  which  raw  sugar  is  purified. 
Raw  sugar  is  chosen  by  the  refiner  by 
the  sharpness  and  brightness  of  its  grain ; 
it  is  put  into  a  copper  pan  or  boiler,  pre- 
viously charged  with  a  certain  quantity 
of  lime-water,  with  which  a  portion  of 
bullock's  blood  has  been  well  mixed  by 
agitation,  and  is  suffered  to  stand  a  night 
to  dissolve.  Early  in  the  morning  fires 
are  lighted  under  the  pans,  and  when 
the  liquid  boils,  the  coagulated  albumen 
of  the  blood  rises  to  the  surface  and  car- 
ries the  impurities  of  the  sugar  with  it. 
The  liquid  is  kept  gently  simmering,  and 
continually  skimmed,  till  a  small  quan- 
tity, taken  out  in  a  metal  spoon,  ap- 
pears perfectly  transparent:  this  general- 
ly takes  from  four  to  five  hours.  The 
clear  syrup  is  then  run  off  into  a  cistern  ; 
the  pans  are  reduced  to  half  their  former 
size,  by  taking  off  a  movable  front,  and  a 
smaller  portion  of  the  purified  syrup  re- 
turned into  each ;  the  fires  are  now  in- 
creased, and  the  sugar  made  to  boil  as 
rapidly  as  possible,  till  a  small  quantity 
taken  on  the  thumb  is  capable  of  being 
drawn  into  threads  by  the  forefinger'; 
the  fire  is  then  damped,  and  the  boiling 
syrup  carried  off  in  basins  to  the  coolers; 
a  fresh  quantity  is  then  pumped  into  the 


618 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[sua 


pans  and  evaporated  as  before.  In  the 
coolers  the  sugar  is  violently  agitated 
with  wooden  oars  till  it  appears  granu- 
lated. It  is  upon  this  agitation  that  the 
whiteness  and  fineness  of  grain  in  the 
refined  sugar  principally  depend  ;  the 
crystals  are  thus  broken  down  while 
forming,  and  the  whole  converted  into  a 
granular  mass,  which  permits  the  color- 
ed liquid  saccharine  matter  to  run  off, 
and  which  would  be  combined  with  the 
solid  if  it  were  suffered  to  form  into 
larger  crystals.  This  granular  texture 
likewise  facilitates  the  percolation  of  wa- 
ter through  the  loaves  in  the  after  pro- 
cess, which  washes  the  minutely  divided 
crystals  from  all  remaining  tinge  of  mo- 
lasses. That  this  is  the  real  theory  of 
the  whitening  of  sugar  by  the  process  of 
refining,  appears  from  a  comparison  with 
the  process  for  making  sugar  candy.  In 
this  the  raw  material  is  cleared  and  boil- 
ed as  above ;  but  instead  of  being  put 
into  coolers  and  agitated,  it  is  poured  into 
pans,  across  which  threads  are  strung,  to 
which  the  crystals  attach  themselves  ; 
th«se  are  set  in  a  stove,  and  great  care  is 
taken  not  to  disturb  the  liquid,  as  upon 
this  depends  the  largeness  and  beauty  of 
the  candy.  In  this  state  it  is  left  for  five 
or  six  days  exposed  to  a  heat  of  about 
95°  ;  when  it  is  taken  out  and  washed 
with  lime-water.  This  takes  off  the  mo- 
lasses from  the  outside ;  but  a  great  quan- 
tity is  combined  in  the  crystal,  and  the 
consequence  is,  that  candy  is  never  whiter 
than  the  sugar  it  is  made  from.  When 
the  sugar  has  attained  the  granular  state 
in  the  coolers,  as  above  described,  it 
is  poured  into  conical  earthen  moulds, 
which  have  been  previously  soaked  a 
night  in  water;  in  these  it  is  again  stirred, 
for  the  purpose  of  extricating  the  air-bub- 
bles, which  would  otherwise  adhere  to 
the  surface  and  render  it  rough  ;  when 
sufficiently  cold,  the  loaves  are  carried  to 
some  of  the  upper  floors  of  the  manufac- 
tory, and  the  paper  covers  being  removed 
from  their  points,  they  are  set  with  their 
broad  ends  upward  upon  earthen  pots. 
The  first  portions  of  the  liquid  molasses 
soon  run  down,  and  leave  the  sugar  much 
whitened  by  the  separation  ;  afterwards, 
pipe-clay  mixed  with  water  to  the  con- 
sistency of  cream  is  put  upon  the  base  of 
the  loaves  to  the  thickness  of  about  an 
inch  ;  the  water  from  this  clay  filters 
through  the  loaf,  and  carrying  with  it  all 
remaining  tinge  of  molasses,  runs  into 
the  pot,  the  clay  being  of  no  other  use 
than  to  retain  the  water  and  prevent  its 
too  rapid  percolation,  by  which  too  much 


of  the  solid  sugar  would  be  dissolved. 
This  process,  called  claying^  is  repeated 
four  or  five  times,  according  to  the  na- 
ture of  the  sugar  and  the  degree  to  which 
it  has  been  boiled.  When  the  loaves  are 
thus  cleansed  from  all  relics  of  color  they 
are  suffered  to  remain  some  time  for  the 
water  to  drain  off;  when  this  is  com- 
pleted, they  are  set  with  their  points  up- 
wards, when  all  remains  of  it  are  equal- 
ly diffused  throughout ;  they  are  then 
stove-dried  at  a  temperature  between  95 
and  100. 

Mr.  M.  Kobinson  has  patented  some 
improvements  in  the  process  of  making 
and  purifying  sugars.  He  applies  to  the 
juice  a  saturated  mixture  ot  alum  and 
lime,  in  the  proportion  of  two  pounds  of 
the  mixture  to  a  hundred  gallons  of  the 
juice.  t  These  being  intimately  mixed, 
the  acid  is  to  be  neutralized  by  the  appli- 
cation of  milk  of  lime,  in  the  proportion 
of  three  pounds  to  a  hundred  gallons.  If 
there  be  an  excess  of  acid,  it  will  be  dis- 
covered by  the  application  of  the  test- 
Saper  usually  employed  by  chemists  to 
etect  acids,  and  more  milk  of  lime  must 
be  added :  and  if  there  be  an  excess  of 
alkali,  it  may  be  discovered  by  the  appli- 
cation of  the  test-paper  used  for  detecting 
alkalies,  and  more  juice  must  be  added. 
When  the  mixture  ceases  to  affect  either 
the  test  for  acid  or  alkali,  the  impurities 
will  be  precipitated,  and  may  thus  be 
separated  ;  and  the  juice  thus  purified  is 
to  be  subjected  to  the  usual  mode  of  cla- 
rification and  concentration. 

Pure  raw  sugar  is  now  obtained  direct 
from  the  sugar-cane,  without  having 
undergone  any  subsequent  process  of 
decolonization  or  refining,  prepared  by 
effecting  the  last  stages  ot  the  concentra- 
tion of  the  cane-juice  in  a  vacuum,  at  a 
temperature  insufficient  to  produce  any 
chemical  changes  in  its  constituent  parts. 
By  this  improved  and  scientific  process 
of  manufacture,  no  molasses,  or  uncrys- 
tallizable  sugar  is  formed,  and  there  is, 
hence,  an  increase  in  the  quantity  of  su- 
gar obtained  of  25  per  cent.  This  estab- 
lishes the  fact,  that  molasses  is  not  an 
educt  of  the  cane,  but  merely  a  product 
of  the  former  operation,  from  the  intense 
ard  long  continued  degree  of  heat  em- 
ployed in  the  processes.  The  sugar,  thus 
obtained,  is  in  perfect,  pure,  transparent, 
granular  crystals,  developing  the  true 
crystalline  form  of  the  sugar,  and  being 
entirely  free  from  the  least  portion  of  un- 
crystallizable  sugar  or  coloring  matter. 
The  new  process  is  now  in  complete  and 
successful  operation  in  eight  estates  in 


suo] 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


610 


Demerara.  From  the  results  of  the  first 
trials,  the  introduction  of  the  present 
improved  process  cannot  fail  soon  to  be- 
come general,  and  the  product  is  much 
approved  in  the  European  market. 

Instead  of  open  kettles  and  pans,  high- 
pressure  steam,  and  vacuum  pans  have 
been  introduced,  producing  an  economy 
in  the  manufacture.  Different  forms  of 
steam  apparatus  are  used  in  different 
places— such  as  that  of  Derosne,  De- 
grand,  and  Zelieux. 

The  process  of  potting  sugar,  or  free- 
ing it  from  syrup  or  treacle,  (molasses,) 
as  practised  in  the  West  Indies  and  other 
countries,  consists  in  allowing  it  to  stand 
for  a  considerable  period  of  time  in  hogs- 
heads, casks,  or  cisterns,  having  holes 
bored  through  their  bottoms.  The  force 
of  gravity  causes  the  syrup  or  treacle 
gradually  to  descend  through  the  sugar, 
and  escape  through  the  holes  in  the  bot- 
tom of  the  hogsheads. 

In  order,  by  the  above  operation,  to 
expel  the  syrup  or  liquid  sufficiently  to 
render  the  sugar  fit  for  market,  much 
time  is  necessarily  consumed.  Besides, 
large  curing-houses,  as  they  are  termed, 
adapted  for  the  purpose  must  be  erected 
and  maintained.  An  improvement  made, 
consists  in  effecting  the  separation  of 
molasses,  by  a  machine  of  a  peculiar  con- 
struction, which  accomplishes  the  same 
through  the  agency  of  centrifugal  force. 

The  objects  of  boiling  and  evaporating 
juice  is  to  separate  extraneous  matters. 
The  addition  of  blood  and  lime  have  for 
their  object,  the  one  to  entangle,  the 
other  to  neutralize  the  thick  and  acid 
impurities,  and  ultimately  separate  them 
from  the  syrup.  Charcoal  or  ivory  black 
is  used  to  remove  coloring  matter.  Dr. 
Scoffern's  new  process  dispenses  with  the 
use  of  lime  and  blood.  It  is  based  on 
the  affinity  of  oxide  of  lead  for  coloring 
matter,  as  well  as  for  the  melacic  and 
other  acids,  all  of  which  have  to  be  re- 
moved from  the  syrup.  Dr.  S.  heats  the 
syrup  280°  Fahr.,  and  then  mixes  it  with 
subacetate  of  lead  •  a  bulky  precipitate  of 
melacitate  of  lead,  formed  with  syrup 
more  or  less  contaminated  with  lead, 
passes  through  the  filter.  This  lead  is 
then  separated  in  the  form  of  an  insolu- 
ble sulphate  by  a  current  of  sulphurous 
acid  sent  through  the  syrup.  After  the 
removal  of  the  metal  has  been  proved  by 
the  test  of  sulphuretted  hydrogen,  chalk 
is  added  to  neutralize  the  acetic  acid, 
and  then  the  syrup  is  thus  sent  to  the 
vacuum  pan  for  granulation. 

The  latest  improvement  in  the  purifi- 


cation of  sugar  is  that  of  M.  Melsens  of 
Belgium.  This  chemist  employs  acid 
sulphites,  more  especially  bi-sulphite  of 
lime,  for  the  double  purpose  of  prevent- 
ing fermentation  by  the  action  of  the 
sulphurous  acid,  and  of  neutralizing  the 
sulphuric  acid  as  fast  as  it  is  formed  by 
means  of  the  lime.  The  results  are,  that 
bi-sulphate  of  lime  can  be  employed  in 
the  extraction  of  sugar  as  an  antiseptic^ 
preventing  the  production  and  action  of 
any  ferment — and  as  a  substance  greedv 
of  oxygen  opposing  an  alteration  which 
its  action  on  the  juice  could  effect.  It 
also  acts  as  a  clarifier,  coagulating  at  212° 
all  albuminous  and  other  coagnlable  mat- 
ters. It  also  bleaches  all  coloring  mat- 
ters, and  prevents  their  after  formation  ; 
and  it  is  alone  capable  of  neutralizing 
any  acids  which  exist  or  may  be  formed 
in  the  juice.  The  quantity  of  sugar 
which  is  now  lost  in  the  bagasse,  in  con- 
sequence of  the  impossibility  of  washing 
it  out  unchanged,  can  be  all  collected  by 
being  dissolved  in  water  charged  with  bi- 
sulphate  of  lime.  Both  M.  Melsens's  and 
Dr.  Scoffern's  processes  are  liable  to  ob- 
jections; but,  even  as  they  stand,  they 
are  large  improvements  in  the  manufac- 
ture. In  the  preparation  of  beet  sugar, 
bi-sulphate  of  lime  is  said  to  be  as  valu- 
able as  for  the  cane.  In  this  manufac- 
ture, M.  Melsens  employs  a  solution  of 
bi-sulphate  of  lime,  of  10°  Beaume  ;  the 
beet-root  pulp  is  sprinkled  over  with  this 
solution  ;  2*  parts  of  bi-sulphate  are  suf- 
ficient for  100  parts  of  beet- root.  The 
saccharine  solution  marking  7°  or  8° 
Beaume  when  it  comes  from  the  press, 
remains  almost  colorless  when  exposed 
to  the  air,  and  does  not  ferment.  It  is 
then  heated,  without  any  further  addi- 
tion, up  to  100°  C,  and  as  soon  as  it 
boils,  it  is  run  off  and  filtered  ;  the  limpid 
juice  is  then  evaporated  to  30°  Beaume, — 
filtered  a  second  time,  concentrated  to 
the  required  degree,  and  then  set  aside 
to  crystallize. 

M.  Chevreul  states,  in  reference  to  the 
above  process,  that  the  employment  ot 
sulphites  cannot  be  claimed  as  a  new  dis- 
covery. M.  Lacoste,  in  1809,  employed 
sulphurous  acid  ;  and  M.  Proust,  in  1810, 
the  sulphite  of  lime.  M.  de  Bournissae, 
a  prisoner  in  the  fortress  of  Vincennes, 
was  set  at  liberty  in  consideration  of  his 
work  on  the  employment  of  these  sub- 
stances in  the  manufacture  of  sugar  from 
the  grape  ;  and  MM.  Poulet  of  Marseilles, 
Serullas,  Dejardin,  and  Fouruier,  junr., 
of  Nismes,  have  published  accounts  of 
their  researches  on  this  subject. 


620 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sua 


Process  of  M.  Dubrunfavt. — M.  Du- 
brunfaut  employs  hydrate  of  baryta, 
which  separates  the  sugar  from  the  prin- 
cipal part  of  the  salts  and  foreign  matters 
contained  in  the  pulp ;  the  insoluble 
saccharate  of  baryta  is  then  treated  with 
sulphuric  acid,  and  a  perfectly  pure  su- 
gar is  obtained. 

The  following  is  one  of  the  most  recent 
methods  for  the  manufacture  of  maple 
sugar  (see  Maple),  as  given  by  S. 
Tinker,  of  Kichland,  Oswego  co.,  N.  Y. 
The  sap  is  boiled  in  a  potash  and  caldron 
kettle  to  a  thick  syrup,  strain  it  when, 
warm,  let  it  stand  24  hours  to  settle,  then 
pour  it  oft',  heaving  back  all  that  is  im- 
pure. To  clarify  50  pounds,  take  a  quart, 
one  ounce  of  saleratus,  and  the  whites 
of  two  eggs  well  mixed.  Boil  it  again 
until  hard  enough  to  lay  upon  a  saucer, 
then  let  it  stand  in  the  kettle  till  cool ; 
stir  it  very  little,  to  keep  it  from  caking 
in  the  kettle,  or  draining,  use  a  tube  fun- 
nel-shaped, say  15  inches  square  at  the 
top,  coming  to  a  point  at  the  bottom. 
Put  in  the  sugar  when  cold,  tap  it  at  the 
bottom,  and  Keep  a  flannel  cloth  damp 
on  the  top  two  or  three  thicknesses. 
When  drained,  dissolve  the  sugar  in 
pure  warm  water  and  clarify,  and  drain 
it  as  before.  It  is  impossible  to  estimate 
the  amount  of  maple  sugar  produced. 
The  season  exercises  a  remarkable  in- 
fluence, and  the  increased  cutting  of  timber 
in  a  district  annually  lessens  the  crop. 
The  low  price  of  imported  sugar  also 
tends  to  keep  down  its  manufacture. 

It  is  but  a  few  years  since  the  highest 
reach  of  art  in  this  manufacture  produced 
only  a  fine  muscovado-like  sugar,  and  now, 
by  the  improved  processes,  specimens 
are  annually  exhibited  at  the  agricultural 
fairs,  vying  with  the  most  beautiful  loaf 
sugar.  This  has  been  effected  by  great 
attention  to  cleanliness  in  the  preparation 
of  the  sap,  and  in  the  processes  of  purifi- 
cation and  graining. 

The  manufacture  of  sugar  from  beet  de- 
serves more  attention  than  it  has  received 
in  this  country.  It  is  in  France  only  (see 
Beet)  that  its  manufacture  has  been 
tried,  and  resulted  in  ultimate  success, 
bo  as  to  push  the  colonial  sugar  out  of  the 
market. 

In  Ireland,  the  manufacture  was  suc- 
cessful and  remunerating,  but  the  Eng- 
lish Government  laid  on  a  heavy  duty,  in 
order  to  protect  its  "West  India  sugar, 
and  thus  crushed  the  manufacture  from 
beet. 

In  France,  this  growth  of  beet  is  a  com- 
mon branch  of  husbandry,  and  sugar  is 


not  only  made  on  large  scales  by  the  ma- 
nufacturers, but  by  housewives  of  the 
farm-house,  as  a  branch  of  domestic  eco- 
nomy, requiring  not  more  skili  or  trouble 
than  cheese-making  or  brewing. 

The  beet-root  sugar-makers  on  a  large 
scale  refine  their  sugars,  and  produce  su- 
gar which,  for  whiteness  and  beauty,  is 
unequalled  by  the  refined  sugar  from 
West  India  sugar.  Bulk  for  bulk,  how- 
ever, the  refined  West  India  sugar  is 
sweeter  than  the  refined  beet-root  sugar ; 
but,  weight  for  weight,  they  are  equally 
sweet.    A  lump  of  refined  beet-root  su- 

f;ar  of  the  first  quality  is  lighter  than  a 
ump  of  equal  dimensions  of  refined  West 
India  sugar,  probably  because  it  is  more 
pure  and  free  from  extraneous  matter ; 
but  a  pound  weight  of  beet-root  sugar 
differs  from  a  pound  weight  of  West  In- 
dia sugar  only  in  our  receiving  more  of 
these  lumps  in  our  pound  weight.  It  is, 
for  domestic  use,  even  more  economical. 
From  5  to  7  per  cent,  of  raw  or  Musco- 
vado sugar  appears  to  be  the  usual  pro- 
duce from  a  given  weight  of  beet-roots. 
From  a  given  weight  of  this  raw  sugar, 
40  per  cent,  of  the  finest  white  refined 
sugar,  with  15  per  cent,  of  inferior  re- 
fined sugar,  are  the  quantities  produced ; 
making  about  2  lbs.  4-5ths  weight  of  the 
finest  white  refined  sugar  from  every 
100  lbs.  of  raw  beet-roots.  The  pulp 
from  which  the  juice  is  extracted,  and 
the  other  residue  of  the  manufacture,  are 
used  for  feeding  cattle.  According  to 
M.  Chaptal,  the  value  of  the  molasses, 
pulp,  &c.  is  one- fourth  of  the  expense  of 
the  manufacture.  It  is  a  promising  fea- 
ture of  the  manufacture,  that  it  is  linked 
with  the  ordinary  business  of  husbandry 
— that  it  operates  upon  a  known  root  cul- 
tivated for  feeding  cattle,  and  that  the 
farmer,  whether  he  raises  beet-root  for 
feeding  cattle,  or  for  sale  to  the  sugar- 
baker,  is  cultivating  a  green  crop,  which, 
in  his  ordinary  rotation  of  crops,  he 
would  at  any  rate  raise  on  a  part  of  his 
farm. 

The  beet  best  for  sugar  is  white  and 
yellow,  and  that  which  is  red  outside  and 
white  within.  It  thrives  best  in  mixed 
soils.  In  France  the  juice  is  expressed 
with  Burette's  or  Odobel's  rasps  for  po- 
tatoes and  beet.  Tin-rasps  with  holes 
answer  in  a  small  way,  but  the  above 
rasps  arc  cylinders  armed  with  saws  and 
turned  by  machinery.  The  pulp  is  then 
put  in  bags,  and  pressed,  yielding  in 
juice  60  or  75  per  cent,  of  the  weight  of 
the  raw  root.  It  produces  crystals  of  su- 
gar   and    bad-flavored    molasses,    from 


sul] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


621 


which,  however,  good  rectified  spirits  are 
produced. 

Another  mode. — After  the  roots  are  re- 
duced to  pulp  by  rasps,  it  is  placed  in 
bags  and  submitted  to  presses  which 
yield  from  65  to  80  per  cent,  of  juice  from 
the  pulp.  This  marks  from  5°  to  9°  of 
Beaume. 

It  contains  sugar  in  crystals  and  mo- 
lasses ;  also,  water,  leaven,  &c.  It  may 
at  once  be  set  to  ferment  with  its  own 
leaven,  and  it  works  well. 

An  hectare  (2-47  acres)  will  yield  80,000 
or  100,000  lbs.  of  beet-root,  costing  per 
1000  lbs.  about  5  or  6  francs ;  and  1000  lbs. 
yield  700  lbs.  of  juice  of  9°  gravity,  which, 
diluted  to  5°,  yield  7£  gallons  of  fine  spirit 
at  19°,  or  0-941  spec.  grav. 

There  is  even  more  advantage  from 
first  separating  the  sugar,  but  the  mo- 
lasses is  impregnated  with  much  salt- 
petre, though  it  yields  more  spirit  than 
the  molasses  of  the  sugar-cane,  and  the 
flavor  is  very  pleasant.  Properly  treated 
by  fermenting,  22  gallons  of  syrup  yield 
16  or  17  gallons  of  spirit  at  19°.  Some 
add  grain  to  the  fermenting  solution. 
Dombasle  and  other  distillers  get  22  of 
spirit  from  22  of  the  beet-root  molasses. 

White  or  yellow  beet-root,  or  the  white 
inside  with  red  skins,  are  the  best  for 
sugar,  or  for  distillation. 

The  stem  and  leaves  of  the  common 
beet,  when  dried  and  burned,  yield  ashes 
so  rich  in  potass,  that  it  surpasses  many 
of  the  commercial  varieties. 

SUGAE  OF  LEAD,  properly  acetate 
of  lead,  is  prepared  by  dissolving  pure 
litharge,  with  heat,  in  strong  vinegar, 
made  of  malt,  wood,  or  wine,  till  the  acid 
be  saturated.  A  copper-boiler,  rendered 
negatively  electrical  by  soldering  a  strap 
of  lead  within  it,  is  the  best  adapted  to 
this  process  on  the  great  scale.  325  parts 
of  finely  ground  and  sifted  oxide  of  lead, 
require  575  parts  of  strong  acetic  acid,  of 
specific  gravity  7°  Beaume,  for  neutraliza- 
tion, and  afford  960  parts  of  crystallized 
sugar  of  lead.      The   oxide   should  be 

fradually  sprinkled  into  the  moderately 
ot  vinegar,  with  constant  stirring,  to 
prevent  adhesion  to  the  bottomland 
when  the  proper  quantity  is  dissolved, 
the  solution  may  be  weakened  with  some 
of  the  washings  of  a  preceding  process, 
to  dilute  the  acetate,  after  which  the 
whole  should  be  heated  to  the  boiling 
point,  and  allowed  to  cool  slowly,  in  or- 
der to  settle.  The  limpid  solution  is  to 
be  drawn  off  by  a  syphon,  concentrated 
by  boiling  to  the  density  of  32°  B.,  tak- 
ing care  that  there  be  always  a  faint  ex- 


cess of  acid,  to  prevent  the  possibility  of 
any  basic  salt  being  formed,  which  would 
interfere  with  the  formation  of  regular 
crystals.  Should  the  concentrated  liquor 
be  colored,  it  may  be  whitened  by  filtra- 
tion through  granular  bone  black. 

Stoneware  vessels,  with  salt  glaze,  an- 
swer for  crystallizers.  Their  edges  should 
be  smeared  with  candle-grease,  to  pre- 
vent the  salt  creeping  over  them  by 
efflorescent  'vegetation.  ""The  crystals  are 
drained,  and  dried  in  a  stove-room  very 
slightly  heated.  Linen,  mats,  wood,  and 
paper,  imbued  with  sugar  of  lead,  and 
strongly  dried,  readily  take  fire,  and  burn 
away  like  tinder.  When  the  mother  wa- 
ters cease  to  afford  good  crystals,  they 
should  be  decomposed  by  carbonate  of 
soda,  or  by  lime  skilfully  applied,  when 
a  carbonate  or  an  oxide  will  be  obtained, 
fit  for  treating  with  fresh  vinegar.  The 
supernatant  acetate  of  soda  may  be  em- 
ployed for  the  extraction  of  pure  acetic 
acid. 

Acetate  of  lead  is  much  used  in  calico- 

Erinting.  It  is  poisonous,  and  ought  to 
e  prepared  and  handled  with  attention 
to  this  circumstance. 

There  are  two  subacetates  of  lead ;  the 
first  of  which,  the  ter-subacetate,  has 
three  atoms  of  base  to  one  of  acid,  and  is 
the  substance  long  known  by  the  name 
of  Goulard's  extract.  It  may  be  obtained 
by  digesting  with  heat  a  solution  of  the 
neutral  acetate,  upon  pure  litharge  or 
massicot.  The  solution  affords  white 
crystalline  scales,  which  do  not  taste  so 
sweet  as  sugar  of  lead,  dissolve  in  not  less 
than  30  parts  of  water,  are  insoluble  in 
alcohol,  and  have  a  decided  alkaline  re- 
action upon  test  paper.  Carbonic  acid, 
transmitted  through  the  solution,  preci- 
pitates the  excess  of  the  oxide  of  lead  in 
the  state  of  a  carbonate,  a  process  long 
ago  prescribed  by  Thenard  for  making 
white-lead.  This  subacetate  consists  of 
88-66  of  oxide,  and  13-34  acid,  in  100  parts. 
It  is  employed  for  making  the  orange 
sub-chromate  of  lead,  as  also  sometimes 
in  surgery. 

SULPHATE,  is  a  name  .given  to  a  salt 
composed  of  sulphuric  acid  united  to  a 
metallic  oxide. 

SULPHATE  OF  ALUMINA  AND 
POTASSA.     (See&iAm.) 

SULPHATE  OF  AMMONIA,  is  a  salt 
sometimes  formed  by  saturating  the  am- 
monia liquor  of  the  gas-works  with  sul- 
phuric acid ;  and  it  is  employed  for  mak- 
ing carbonate  of  ammonia.  (See  Am:«io- 
nia.  and  Gas  Coal  Manufacture.) 

SULPHATE    OF    BAKYTA,    is  the 


622 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[« 


mineral  called  heavy-spar,  which  fre- 
quently forms  the  gansrue  or  vein-stone 
of  lead  and  other  metallic  ores. 

SULPHATE  OF  COPPER,  Roman  or 
Uv-e  vitriol,  is  a  salt  composed  of  sul- 
phuric acid  and  oxide  of  copper,  and  may 
he  formed  by  boiling  the  concentrated 
acid  upon  the  metal,  ^in  an  iron  pot.  It 
is,  however,  a  natural  product  of  many 
copper  mines,  from  which  it  flows  out  in 
the  form  of  a  blue  water,  being  the  result 
of  the  infiltration  of  water  over  copper 
pyrites,  which  has  become  oxygenated 
by  long  exposure  to  the  air  in  subter- 
ranean excavations.  The  liquid  is  con- 
centrated by  heat  in  copper  vessels,  then 
set  aside  to  crystallize.  The  salt  forms 
in  oblique  four-sided  tables,  of  a  fine  blue 
color;  has  a  specific  gravity  of  2-104;  an 
acerb,  disagreeable,  metallic  taste  ;  and, 
when  swallowed,  it  causes  violent  vomit- 
ins:.  It  becomes  of  a  pale  dirty  blue,  and 
effloresces  slightly,  on  long  exposure  to 
the  air ;  when  moderately  heated,  it  loses 
36  per  cent,  of  water,  and  falls  into  a 
white  powder.  It  dissolves  in  4  parts  of 
water,  at  60°,  and  in  2  of  boiling  water, 
but  not  in  alcohol ;  the  solution  has  an 
acid  reaction  upon  litmus  caper.  When 
strongly  ignited,  the  acid  flies  off,  and  the 
black  oxide  of  copper  remains.  The  con- 
stituents of  crystallized  sulphate  of  cop- 
per are — oxide,  31-80;  acid,  32-14;  and 
water,  36-06.  Its  chief  employment  in 
this  country  is  in  dyeing,  and  for  pre- 
paring certain  green  pigments.  {See 
Scheele's  and  Schweinfurth  Green.) 
Farmers  sprinkle  a  weak  solution  of  it 
upon  their  grains  and  seeds  before  sow- 
ing them,  to  prevent  their  being  attacked 
by  birds  and  insects. 

SULPHATE  OF  IRON.  Green  vi- 
triol, copperas.  Names  given  to  the  com- 
bination of  sulphuric  acid  with  protoxide 
of  iron.     It  is  made  up — 

1  Equivalent  sulphuric  acid 40 

1  Equivalent  protoxide  iron 28 

7  Equivalents  of  water 63 

131 

It  is  generally  made  from  the  bitumin- 
ous shales  of  or  near  the  coal  beds.  The 
shales  of  the  midland  counties  of  New 
York  afford  the  materials  for  making  sul- 
phate of  iron;  and  in  the  coal  regions 
along  the  slope  of  the  Alleghanics  it  is 
found  abundantly,  and  is  found  crystal- 
lized in  eastern  Tenessee. 

Sulphate  of  iron  is  generally  made  from 
combinations  of  iron  with  brimstone, 
called  iron  pyrites,  or,  in  common  lan- 
guage, copperas  stones,  gold  stones,  or 


horse  gold.  These  stones  being  collected 
in  great  quantity,  are  laid  in  heaps  about 
two  feet  thick,  upon  a  clay  floor,  sur- 
rounded by  boards,  that  direct  the  rain- 
water that  falls  upon  them,  to  flow  into  a 
cistern.  The  copperas-stones  are  five  or 
six  years  before  they  yield  any  consider- 
able quantity  of  strong  liquor.  In  time, 
the  stones  turn  to  a  vitriolic  earth,  which 
swells  and  ferments  like  leavened  dough. 
When  a  bed  is  come  to  perfection,  it  is 
refreshed  every  four  years,  by  laving 
fresh  copperas-stones  on  the  top.  When 
a  new  bed  is  made,  the  work  is  hastened 
by  mixing  a  good  quantity  of  the  old  fer- 
mented earth  with  the  new  stones. 

When  the  copperas-liquor  is  14  penny- 
weights strong  it  is  esteemed  rich.  It 
will  dissolve  the  shell  off  an  egg  in  three 
minutes,  and  produce  holes  in  any  clothes 
on  which  it  may  fall. 

The  liquor  is  boiled  in  leaden  vessels, 
old  iron  is  put  in  at  first,  and  more  added 
as  fast  as  it  dissolves.  The  boiling  is 
esteemed  finished  when  a  little  of  the  li- 
quor, put  into  an  earthen-ware  dish,  and 
cooled,  deposits  crystals  on  the  sides. 

In  some  works,  iron  is  added  to  the 
liquor  in  the  cistern  ;  and,  of  course,  less 
is  required  in  the  boiling.  There  is  ano- 
ther kind  of  pyrites,  which  contains  a 
double  proportion  of  sulphur;  this  sort 
does  not  alter  by  exposure  to  the  weather, 
until  the  extra  proportion  of  sulphur  is 
removed,  either  by  roasting  in  piles,  or 
by  distilling  in  close  vessels.  There  is 
also  a  kind  of  bituminous  earth,  that  pro- 
duces copperas  by  exposure  to  the  air, 
and  from  which  it  may  be  obtained  by 
washing  with  water  in  the  usual  manner. 
Copperas  is  also  manufactured  by  dis- 
solving old  iron  in  weak  sulphuric  acid, 
at  35°~Beaume,  and  crystallizing  the  solu- 
tion. 

Its  color  is  a  bright  green,  and  its  taste 
very  astringent.  A  solution  in  water, 
dropped  on  oak  bark,  instantly  produces 
a  black  spot.  It  is  in  request  with  dyers, 
tanners,  and  the  manufacturers  of  ink, 
and,  for  their  use,  is  artificially  prepared 
from  pyrites,  which  being  moistened  and 
exposed  to  the  air  a  crust  is  formed  upon 
it,  to  be  dissolved  in  water,  and,  from 
this,  crystals  of  vitriol  are  obtained  by 
evaporation.  Green  vitriol  is  used  in 
dying  woollen  articles,  hats,  &c,  black, 
and  it  is  the  basis  of  ink,  and  used  in  the 
manufacture  of  Prussian  blue.  Reduced 
to  powder,  dried,  and  mixed  with  pow- 
der of  galls,  it  forms  the  dry,  portable  ink- 
cakes  and  powders. 

When  the  green  sulphate  is  exposed 


bul] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


623 


to  the  air  it  is  decomposed,  and  gradually 
converted  into  red  oxide  of  iron  and  per- 
sulphate of  iron.  When  copperas  is 
heated  in  a  crucible,  or  over  a  lamp,  it  is 
converted  into  the  red  oxide  or  peroxide 
of  iron. 

An  excellent  powder  for  applying  to 
razor-strops,  is  made  by  igniting  together 
in  a  crucible  equal  parts  of  well-dried 
copperas  and  sea  salt.  The  heat  must  be 
slowly  raised  and  well  regulated,  other- 
wise the  materials  will  boil  over  in  a  pasty 
state,  and  the  product  will  be  in  a  great 
measure  lost.  When  well  made,  out  of 
contact  of  air,  it  has  the  brilliant  aspect 
of  plumbago.  It  has  a  satiny  feel,  and  is 
a  true  fer  olegiste,  similar  in  composition 
to  the  Elba  iron  ore.  It  requires  to  be 
ground  and  elutriated ;  after  which  it 
affords,  on  drying,  an  impalpable  pow- 
der, that  may  be  either  rubbed  on  a  strop 
of  smooth  buff  leather,  or  mixed  up  with 
hog's-lard  or  tallow  into  a  stiff  cerate. 

SULPHATE  OF  MANGANESE  is 
prepared  on  the  great  scale  for  the  calico- 
printers,  by  exposing  the  peroxide  of  the 
metal  and  pitcoal  ground  together,  and 
made  into  a  paste  with  sulphuric  acid,  to 
a  heat  of  400°  F.  On  lixiviating  the  cal- 
cined mass,  a  solution  of  the  salt  is  ob- 
tained, which  is  to  be  evaporated  and 
crystallized.  It  forms  pale  amethyst- 
colored  prisms,  which  have  an  astringent 
bitter  taste,  dissolve  in  2h  parts  of  water, 
and  consist  of— protoxide  of  manganese 
81-93,  sulphuric  acid  35-87,  and  water 
32-20,  in  100  parts. 

SULPHATE  OF  MERCURY  is  a 
white  salt  which  is  used  in  making  cor- 
rosive sublimate.  (See  Mercury.)  The 
subsulphate,  called  turbith  mineral,  is  a 
pale  yellow  pigment,  and  may  be  pre- 
pared by  washing  the  white  sulphated 
peroxide  with  hot  water,  which  resolves 
it  into  the  soluble  su persulphate,  and  the 
insoluble  subsulphate,  or  turbith.  It  is 
poisonous. 

SULPHATE    OF    ZINC,    called  also 
white  vitriol,  is  commonly  prepared  in 
the  Harz,  by  washing  the  calcined  and 
effloresced  sulphuret  of  zinc  or  blende, 
on  the  same  principle  as  green  and  blue 
vitriol  are  obtained  from  the  sulphurets 
of  iron  and  copper.      Pure  sulphate  of 
zinc  may  be  made  most  readily  by  dis-  j 
solving  the  metal    in    dilute  sulphuric 
acid,   evaporating   and  crystallizing  the 
solution.      It  forms    prismatic   crystals,  i 
which  have  an  astringent,  disagreeable,  | 
metallic  taste;   they  effloresce  in  a  dry  ; 
air,  dissolve  in  2-3  parts  of  water  at  60°,  j 
and  consist  of— -oxide  of  zinc,  28-29;  acid,  I 


28*18;  water,  43*53.  Sulphate  of  zinc  is 
used  for  preparing  drying  oils  for  var- 
nishes, and  in  the  reserve  or  resist  pastes 
of  the  calico-printer. 

SULPHITES  are  a  class  of  salts,  con- 
sisting of  sulphurous  acid,  combined  in 
equivalent  proportions  with  the  oxidized 

SULPHUR.  Brimstone.  A  yellow 
brittle  mineral  product,  found  in  various 
parts  of  the  world  ;  but  apparently  most 
abundant  in  volcanic  regions.  It  most 
commonly  occurs  massive;  but  it  is 
sometimes  met  with  crystallized  in  the 
form  of  an  oblique  rhombic  octoedron. 
Fine  specimens  of  this  description  are 
seen  in  our  mineral  cabinets,  and  bear  a 
high  price.  A  considerable  quantity  of 
sulphur  is  also  obtained  from  some  of  its 
metallic  combinations,  such  as  the  sul- 
phurets of  cooper  and  of  iron.  These 
ores  are  heated,  or  roasted,  as  it  is  term- 
ed, in  furnaces  so  constructed  that  the 
sulphur  vapor  may  be  condensed,  and 
from  time  to  time  collected ;  this,  when 
purified  by  fusion,  is  cast  into  moulds, 
and  forms  common  or  roll  brimston-e. 
Small  quantities  of  sulphur  also  occur  in 
several  animal  and  vegetable  products, 
and  are  frequently  recognized  by  the  odor 
of  sulphuretted  hydrogen  which  they 
evolve"  during  putrefaction.  Sulphur  i3 
a  non-conductor  of  electricity,  insipid, 
and  inodorous,  unless  rubbed  or  heated, 
when  it  evolves  a  sulphurous  smell.  Its 
specific  gravity  is  1-99.  It  melts  at  about 
216°  ;  and  when  heated  to  about  250°  it 
becomes  a  limpid,  amber-colored  liquid  ; 
if  the  heat  be  raised  to  about  450°,  it 
again  becomes  viscid  and  deeper  colored ; 
at  480°  up  to  its  boiling  point  it  acquires 
rather  more  fluidity;  at  about  600°  it 
rises  rapidly  in  vapor,  and  in  close  ves- 
sels condenses  in  the  form  of  a  fine  yel- 
low powder,  composed  of  crystalline 
grains :  in  this  state  it  is  called  flowers  of 
sulphur.  The  earthy  and  metallic  im- 
puritieswhich,  with  a  portion  of  sulphur, 
remain  in  the  subliming  vessel,  were  for- 
merly called  sulphur  vivum.  When  sul- 
phur in  its  viscid  state  of  fusion  is  pour- 
ed into  water  it  becomes  a  ductile  mass, 
which  slowly  hardens,  and  which  is  often 
used  for  taking  impressions  of  seals  and 
medals.  When  sulphur  is  in  the  form  of 
vapor  it  is  of  a  dense  orange  color :  its 
specific  gravity  in  that  state  is  about  6*6 
and  100  cubic  inches  of  it  should  there- 
fore weigh  about  206  grains. 

There  is  another  form  of  sulphur,  which 
is  sometimes  called  milk  of  sulphur  (lac 
sulphuris)  and  which  is  a  hydrate  of  sul- 


624 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[SUL 


fhur  ;  it  is  obtained  by  precipitating  sul- 
phur by  muriatic  acid  from  certain  of  its 
alkaline  solutions.  When  sulphur  which 
has  been  melted  is  suffered  to  cool  slow- 
ly, its  interior  often  exhibits  prismatic 
crystals ;  and  very  beautiful  specimens  of 
this  artificial  crystallization  of  sulphur 
may  be  obtained  by  melting  a  few  pounds 
of  it  in  a  crucible  or  ladle,  and  when  par- 
tially cooled  piercing  the  outer  crust  and 
inverting  the  vessel,  so  that  the  interior 
liquid  part  may  run  out;  on  breaking 
the  mass  when  cold,  the  cavity  will  be 
found  lined  with  prismatic  crystals. 

The  results  of  the  combustion  of  sul- 
phur, its  equivalent  number  (16),  and 
several  other  details  respecting  its  com- 
binations and  uses,  are  given  under  the 
heads  of  Sulphuretted  Hydrogen,  and 
of  Sulphuric  and  Sulphurous  Acids. 

Sulphur  is  insoluble  in  water  ;  it  dis- 
solves in  boiling  oil  of  turpentine,  and  is 
deposited  often  in  crystals  as  the  solution 
cools.  It  is  also  soluble  in  alcohol,  if 
both  substances  be  brought  together  in 
the  state  of  vapor.  It  combines  also  with 
chlorine,  bromine,  and  iodine.  Its  na- 
tive combinations  with  the  metals  form 
some  of  the  most  important  ores.  It  is 
from  the  sulphurets  of  lead  and  of  copper 
that  the  commercial  demands  for  these 
valuable  metals  are  almost  exclusively 
supplied. 

Sulphur  is  of  great  importance  in  the 
arts.  It  is  used  extensively  in  the  ma- 
nufacture of  gunpowder,  and  in  the  for- 
mation of  sulphuric  acid,  or  oil  of  vitriol. 

A  great  portion  of  the  sulphur  em- 
ployed in  Europe  is  obtained  from  Sicily, 
to  which  country  its  extraction  is  so  impor- 
tant, that,  out  of  2,000,000  inhabitants, 
about  20,000  are  employed  in  it ;  and  the 
amount  received  by  Sicily  for  sulphur 
exported,  amounts  to  $1,830,000  per  an- 
num. 

There  are  no  minerals,  containing  pure 
sulphur,  found  in  the  United  States  ;  at 
least,  not  in  sufficient  quantity  to  be  of 
practical  use.  The  chief  sources  from 
which  sulphur  can  be  obtained,  are  the 
sulphurets  of  the  metals,  which  we  pos- 
sess in  great  abundance.  Sulphur  may 
be  extracted  from  iron  pyrites,  by  simple 
distillation  in  iron  or  stone,  when  they 
yield  one  half  the  sulphur  they  can  con- 
tain ;  the  remainder,  sulphuret  of  iron, 
is  easily  converted  into  copperas.  Al- 
most the  whole  of  the  crude  sulphur  of 
this  country  is  imported  from  Europe. 

Sulphur  exists  in  nature,  not  only  in 
the  mineral,  but  most  abundantly  in  the 
vegetable    kingdom    also :    without   it 


plants  could  not  exist ;  for  there  is  no 
plant  in  which  albumen  is  not  found,  and 
to  the  existence  of  albumen,  sulphur  is 
an  indispensable  requisite.  In  the  ani- 
mal kingdom,  too,  sulphur  exists  in  large 
quantities. 

SULPHURATION,  is  the  process  by 
which  woollen,  silk,  and  cotton  goods  are 
exposed  to  the  vapors  of  burning  sul- 
phur, or  to  sulphurous  acid  gas.  In  the 
article  Straw -hat  Manufacture,  this 
operation  has  been  referred  to. 

Sulphuring-rooms  are  sometimes  con- 
structed upon  a  great  scale,  in  which 
blankets,  shawls,  and  woollen  clothes  may 
be  suspended  freely  upon  poles  or  cords. 
The  floor  is  flagged  with  a  sloping  pave- 
ment, to  favor  the  drainage  of  the  water 
that  drops  from  the  moistened  cloth. 
The  iron  or  stoneware  vessels,  in  which 
the  sulphur  is  burned,  are  set  in  the  cor- 
ners of  the  apartment.  The  windows 
and  the  entrance  door  must  be  made  to 
shut  hermetically  close.  In  the  lower  part 
of  the  door  there  should  be  a  small  open- 
ing, with  a  sliding  shutter,  which  may 
be  raised  or  lowered  by  the  mechanism 
of  a  cord  passing  over  a  pully. 

The  aperture  by  which  the  sulphurous 
acid  and  azotic  gases  are  let  off,  m  order 
to  carry  on  the  combustion,  should  be 
somewhat  larger  than  the  opening  at  the 
bottom.  A  lofty  chimney  carries  the 
noxious  gases  above  the  building,  and 
diffuses  them  over  a  wide  space. 

When  the  chamber  is  to  be  used,  the 
goods  are  hung  up,  and  a  small  firs  is 
made  in  the  draught-stove.    The  proper 

Suantity  of  sulphur  being  next  put  into 
le  shallow  pans,  it  is  kindled,  the  en- 
trance door  is  closed,  as  well  as  its  shut- 
ter, while  a  vent-hole  near  the  ground  is 
opened  by  drawing  its  cord,  which  passes 
over  a  pulley.  After  a  few  minutes, 
when  the  sulphur  is  fully  kindled,  that 
vent-hole  must  be  almost  entirely  shut, 
by  relaxing  the  cord ;  when  the  whole 
apparatus  is  to  be  let  alone  for  a  sufficient 
time. 

The  object  of  the  preceding  precautions 
is  to  prevent  the  sulphurous  acid  gas 
escaping.  This  is  secured  by  closing  the 
door  imperfectly,  so  that  it  may  admit  of 
the  passage  of  somewhat  more  air  than 
can  enter  by  the  upper  seams,  and  the 
smallest  quantity  of  fresh  air  that  can 
support  the  combustion. 

SULPHURETTED  HYDROGEN,  is  a 
gas,  composed  of  one  part  of  hydrogen 
and  sixteen  parts  of  sulphur,  by  weight. 
Its  specific  gravity  is  1*1912,  compared  to 
air=  l'OOOO.    It  is  the  active  constituent 


sul] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


625 


of  the  sulphurous  mineral  waters.  When 
breathed,  it  is  very  deleterious  to  animal 
life  ;  and  being  nearly  twice  as  dense  as 
air,  it  may  be  poured' from  its  generating 
bottle  into  cavities  ;  a  scheme  success- 
fully employed  by  M.  Thenard  to  destroy 
rats  in  their  holes. 

SULPHURIC  ACID.  The  most  im- 
portant compound  of  sulphur  with  oxy- 
gen. It  occurs  native  in  volcanic  dis- 
tricts in  equatorial  Asia:  and  in  Italy  and 
Sicily,  and  occasionally  in  springs,  where 
there  is  organic  matter  brought  into  con- 
tact with  a  ferruginous  sulphate:  this 
occurs  in  some  of  the  springs  of  western 
New  York.  When  pure  or  anhydrous 
(without  water)  it  consists  of  an  equiva- 
lent of  sulphur  united  with  three  equi- 
valents of  oxygen,  but  it  is  never  known 
except  as  a  hydrated  acid.  The  manu- 
factories where  it  is  made  require  large 
room,  and  entail  great  expense  for  the 
purchase  of  platinum  stills.  The  manu- 
facture is  but  small  in  this  country :  the 
greater  portion  being  derived  from  Eng- 
land, of  which  there  are  50,000  tons  an- 
nually made. 

Hydrated  sulphuric  acid  has  been  known 
since  the  fifteenth  century.  There  are 
two  distinct  processes  by  which  it  is  at 
the  present  time  prepared,  namely,  by 
the  distillation  of  green  sulphate  of  iron, 
and  by  the  oxidation  of  sulphurous  acid 
bv  nitrous  acid. 

'The  first  process  is  still  carried  on  at 
Nordhausen  in  Saxony  ;  the  sulphate  of 
iron,  derived  from  the  oxidation  of  iron 
pyrites,  is  deprived  by  heat  of  the  greater 
part  of  its  water  of  crystallization,  and 
subjected  to  a  high  red  heat  in  earthen 
retorts,  to  which  receivers  are  fitted  as 
soon  as  the  acid  begins  to  distil  over.  (  A 
part  gets  decomposed  by  the  very  high 
temperature ;  the  remainder  is  driven  off 
in  vapor,  which  is  condensed  by  the  cold 
vessel.  The  product  is  a  brown  oily  li- 
quid, of  about  1-9  specific  gravity,  fuming 
in  the  air,  and  very  corrosive.  It  is 
chiefly  made  for  the  purpose  of  dissolv- 
ing indigo. 

N'tT  acid         (  g^JS"  }«• 

46  06       "        |  Oxygen  16 

Sulphurous  acid  j   Sulphur  32-18 

64-18  )   Oxygen  82 

Water 18 

Such  is  the  simplest  view  that  can  be 
taken  of  the  production  of  sulphuric  acid 
in  ths  leaden  chamber,  but  it  is  too  much 
to  affirm  that  it  is  strictly  true ;  it  may 
bo  more  complex.  When  a  little  water 
27 


The  second  method,  which  is  perhaps, 
with  the  single  exception  mentioned,  al- 
ways followed  as  the  more  economical, 
depends  upon  the  fact  that  when  sul- 
phurous acid,  nitrous  acid,  and  water  are 
present  in  certain  proportions,  the  sul- 
phurous acid  becomes  oxidized  at  the  ex- 
f>ense  of  the  nitrous  acid,  which  by  the 
oss  of  one-half  of  its  oxygen  sinks  to  the 
condition  of  deutoxide  of  nitrogen.  The 
operation  is  thus  conducted : — A  large 
and  very  long  chamber  is  built  of  sheet- 
lead  supported  by  timber  framing ;  on 
the  outside  at  one  extremity  a  small  fur- 
nace or  oven  is  constructed,  having  a 
wide  tube  leading  into  the  chamber.  In 
this  sulphur  is  kept  burning,  the  flame 
of  which  heats  a  crucible  containing  a 
mixture  of  nitre  and  oil  of  vitriol.  A 
shallow  stratum  of  water  occupies  the 
floor  of  the  chamber,  and  sometimes  a  jet 
of  steam  is  also  introduced.  Lastly,  an 
exit  is  provided  at  the  remote  end  of  the 
chamber  for  the  spent  and  useless  gases. 
The  effect  of  these  arrangements  is  to 
cause  a  constant  supply  of  sulphurous 
acid,  atmospheric  air,  nitric  acid  vapor, 
and  water  in  the  state  of  steam,  to  be 
thrown  into  the  chamber,  there  to  mix 
and  re-act  upon  each  other.  The  nitric 
acid  immediately  gives  up  a  part  of  its 
oxygen  to  the  sulpnurous  acid,  becoming 
nitrous ;  it  does  not  remain  in  this  state, 
however,  but  suffers  further  de-oxidation 
until  it  becomes  reduced  to  deutoxide  of 
nitrogen.  That  substance  in  contact  with 
free  oxygen,  absorbs  a  portion  of  the  lat- 
ter, and  once  more  becomes  nitrous  acid, 
which  i3  again  destined  to  undergo  a  de- 
oxidation  by  a  fresh  quantity  of  sulphur- 
ous acid.  A  very  small  portion  of  nitrous 
acid,  mixed  with  atmospheric  air  and  sul- 
phurous acid,  may  thus  in  time  convert 
an  indefinite  amount  of  the  latter  into 
sulphuric  acid,  by  acting  as  a  kind  of  car- 
rier between  the  oxygen  of  the  air  and 
the  sulphurous  acid.  The  presence  of 
water  is  essential  to  this  re-action. 

We  may  thus  represent  the  change : — 

Deutoxide  of  Nitrogen  80-06. 


Hydrated  Sulphuric  acid  98-18. 

is  put  at  the  bottom  of  a  large  glass  globe 
so  as  to  maintain  a  certain  degree  of  hu- 
midity in  the  air  within,  and  sulphurous 
and  nitrous  acids  are  introduced  by  se- 
parate tubes,  symptoms  of  chemical  ae- 


626 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[sum 


tion  become  immediately  evident,  and 
after  a  little  time,  a  white  crystalline  mat- 
ter is  observed  to  condense  on  the  sides 
of  the  vessel.  This  substance  appears  to 
be  a  compound  of  sulphuric  acid,  hypon- 
itrous  acid,  and  a  little  water.  \V  lien 
thrown  into  water,  it  is  resolved  into 
sulphuric  acid,  dentoxide  of  nitrogen, 
ana  nitric  acid.  This  curious  body  is 
certainly  very  often  produced  in  large 
quantity  in  the  leaden  chambers,  but 
that  its  production  is  indispensable  to 
the  success  of  the  process,  and  constant 
when  the  operation  goes  on  well  and  the 
nitrous  acid  is  not  in  excess,  may  per- 
haps admit  of  doubt. 

The  water  at  the  bottom  of  the  cham- 
ber thus  becomes  loaded  with  sulphuric 
acid ;  when  a  certain  degree  of  strength 
has  been  reached,  it  is  drawn  off  and  con- 
centrated by  evaporation,  first  in  leaden 
pans,  and  afterwards  in  stills  of  platinum, 
until  it  attains  a  density  (when  cold)  of 
1*84,  or  thereabouts ;  it  is  then  transferred 
to  carboys,  or  large  glass  bottles  fitted  in 
baskets,  for  sale.  An  inferior  kind  of 
acid  is  now  made  by  burning  iron  pyrites, 
or  poor  copper  ore,  as  a  substitute  for  Si- 
cilian sulphur ;  this  is  chiefly  used  by 
the  makers  for  their  own  consumption ; 
it  very  frequently  contains  arsenic. 

Sulphuric  acid,  is   a  limpid    colorless 
fluid,  of  a  spec.  grav.  of  1-8.    It  boils  at 
.  620°  ;  it  freezes  at  15°.     But  the  temper- 

*  ature  at  which  the  diluted  acid  congeals 

is  singularly  modified  by  the  quantity  of 
water  which  it  contains.  When  of  the 
spec.  grav.  of  1*78  (which  may  be  regard- 
ed as  a  compound  of  1  atom  of  dry  acid 
and  2  of  water),  it  freezes  at  40°,  and  re- 
mains solid  for  a  long  time  at  several  de- 
grees above  that  point :  if  the  density  be 
either  diminished  or  increased,  a  greater 
cold  is  required  to  congeal  it. 

It  is  acrid  and  caustic,  and  intensely 
acid  in  all  its  characters,  even  when 
largely  diluted.  Its  attractions  for  bases 
is  such  that  it  separates  or  expels  all  other 
acids  more  or  less  perfectly  from  their 
combinations.  Its  affinity  for  water  is 
such  that  it  rapidly  absorbs  it  from  the 
atmosphere,  and  when  mixed  with  water 
much  heat  is  evolved  ;  thus  by  suddenly 
mixing  4  pans  of  the  acid  and  1  of  water 
at  60°",  the  temperature  rises  to  300°. 
Its  attraction  for  water  also  causes  the 
sudden  liquefaction  of  snow  ;  and  if  mix- 
ed with  it  in  due  proportion,  an  intense 
cold  is  the  consequence.  It  acts  ener- 
getically upon  animal  and  vegetable  sub- 
stances,   generally  charring   them,    and 


often,  as  in  the  case  of  sugar,  with  singu- 
lar rapidity. 

The  acid,  as  it  usually  occurs  in  com- 
merce, under  the  name  of  concentrated 
sulphuric  acid,  is  a  compound  of  1  atom 
of  anhydrous  acid  and  1  of  water.  The 
anhydrous  sulphuric  acid  is  constituted 
of  16  sulphur  (1  atom),  and  24  oxygen 
(3  atoms) ;  its  equivalent,  therefore,"  is 
16+24=40  :  this  is  the  composition  of  the 
acid  as  it  exists  in  the  anhydrous  sul- 
phates. The  strongest  liquid  acid  con- 
sists of  40  of  the  dry  or  anhydrous  acid 
(1  atom),  and  9  water  (1  ato'm),  and  is 
therefore  represented  by  the  equivalent 
40+9=49. 

Sulphurous  acid,. — A  compound  of  1 
equivalent  of  sulphur  and  2  equivalents 
of  oxygen  :  5*  is  a  gas  which  is  poison- 
ous, producing  suffocation.  It  may  be 
made  by  burning  sulphur  in  a  chamber 
with  air" when  the  acid  vapors  rise.  It  is 
also  made  by  boiling  sulphuric  acid  with 
charcoal  or  carbonaceous  matter,  when 
the  sulphuric  loses  its  oxygen  and  is  con- 
verted into  sulphurous  acid. 

It  is  found  to  escape  in  torrents  from 
the  mouths  of  volcanoes  ;  and  it  is  gener- 
ally believed  that  its  inhalation  caused 
the  death  of  Pliny  the  elder,  A.D.  99.  It 
is  found  that  this  acid  is  the  only  mate- 
rial with  which  woollens  and  silks  can  be 
bleached,  and  its  application  to  this  pur- 
pose is  very  simple  and  extensive.  Sul- 
phurous acid  is  soluble  in  water,  but  this 
solution  had  no  application  until  of  late 
years.  It  is  now  used  for  destroying  co- 
lors. There  is  a  substance  imported  in- 
to England  from  the  Cape  of  Good  Hope, 
called  jute,  which  had  hitherto  been  con- 
sidered of  no  use,  from  the  supposed  im- 
possibility of  bleaching  its  fibre  ;  but  this 
has  lately  been  effected,  and  a  white  and 
silky  appearance  imparted  to  it.  Sul- 
phurous acid  is  the  only  thing  by  which 
this  bleaching  can  be  effected;  for  if 
placed  in  an  alkaline  liquor,  jute  is  re- 
duced into  a  soft  pulpy  state. 

SUMACH.  The  powder  of  the  leaves, 
peduncles,  and  young  branches  of  the 
Rhus  coriaria  and  Ehus  cotinus,  shrubs 
which  grow  in  Hungary,  the  Bannat,  and 
the  lllyrian  provinces.  Both  kinds  con- 
tain tannin,  with  a  little  yellow  coloring 
matter,  and  area  good  deal  employed 
for  tanning  light-colored  leathers ;  but 
the  first  is  the  best.  With  mordants,  it 
dyes  nearly  the  same  colors  as  galls. 
In  calico-printing,  sumach  affords,  with 
a  mordant  of  tin,  a  yellow  color ;  with 
acetate  of  iron,  weak  oV  strong,  a  gray  or 


bym] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


627 


black;  and  with  sulphate  of  zinc,  a 
brownish  yellow.  A  decoction  of  sumach 
reddens  litmus  paper  strongly;  gives 
white  flocks  with  the  proto-muriate  of 
tin ;  pale  yellow  flocks  with  alum  ;  dark 
blue  flocks  with  red  sulphate  of  iron, 
with  an  abundant  precipitate. 

The  R.  Typhina  grows  in  the  Northern 
States  :  the  bark  is  powdered  for  tanning. 
The  Ji.  Glabra  grows  in  the  Middle 
States.  The  R.  Pumila  grows  in  the 
mountains  of  Carolina.  Tt  is  the  most 
poisonous  of  the  genus.  Thei?.  Venenata 
is  found  in  the  Northern  and  Middle 
States.  R.  Copallina  grows  in  the  Middle 
and  Southern  States.  Several  species  of 
the  celebrated  Japan  varnish  is  obtained 
from  a  species  of  Rhus. 

SURVEYING.  In  practical  mathema- 
tics, the  art  of  determining  the  bounda- 
ries and  superficial  extent  of  a  portion  of 
the  earth's  surface.  The  object  of  a  sur- 
vey may  be  either  to  ascertain  the  con- 
tents of  a  field  or  portion  of  land,  or  to 
determine  the  relative  distances  and  bear- 
ings of  the  most  prominent  objects  of  a 
country  for  the  purpose  of  constructing 
a  map,  or  to  determine  the  form  and  di- 
mensions of  a  portion  of  the  earth's  sur- 
face with  a  view  to  deduce  the  magnitude 
and  figure  of  the  earth  by  comparing  the 
geodetieal  distances  between  given  points 
with  their  astronomical  positions.  In  all 
cases  the  operation  is  conducted  on  the 
same  principles ;  but  while  the  first  re- 
quires only  the  application  of  the  merest 
elements  of  arithmetic  and  trigonometry, 
the  last  can  only  be  accomplished  with 
the  aid  of  instruments  of  the  most  refin- 
ed description,  and  processes  of  calcula- 
tion deduced  from  mathematics  of  the 
highest  order. 

SUSPENSION  BRIDGE.  In  archi- 
tecture, abridge  in  which  the  roadway,  in- 
stead of  being  carried  over  the  support- 
ing points,  is  suspended  from  them,  the 
supporting  points  being  chains  or  other 
flexible  materials.  The  principle  has  re- 
cently been  carried  to  a  great  extent  in 
England,  as  in  the  case  of  the  Menai 
bridge  ;  but  its  application  is  old,  and  has 
long  been  practised  among  people  who 
have  attained  very  little,  if  any,  skill  in 
the  arts.     (See  Bridge.) 

SWINE  STONE.  Eetid  or  bituminous 
limestone,  which  exhales  a  disagreeable 
odor  on  friction. 

SWING.  The  ship  at  anchor  is  said 
to  swing  when  she  changes  her  position 
at  the  turn  of  the  tide. 

SWJVEL.  In  gunnery,  a  small  can- 
non ;  so  called  from  its  being  fixed  in  a 


\  by  means  of  which  it  may  be  di- 
rected to  any  object.  Swivels  are  chiefly 
used  at  sea,  and  are  placed  on  the  ship's 
side,  stern,  or  bow,  and  also  in  the  tops. 
SWITCH.  The  mechanism  by  which 
parallel  or  diverging  rails  are  connected. 


The  annexed  cut  at  once  illustrates  the 
principle,  and  gives  an  example  of  a  very 
common  arrangement  of  switches  ;  a,  a, 
is  the  straight,  and  b,  b,  the  diverging 
line  of  rails ;  c,  c,  the  switches,  laid  upon 
a  broad  fiat  plate,  and  turning  on  a  joint 
at  one  extremity ;  d,  a  rod  joining  the 
opposite  ends,  so  as  to  render  the  motion 
or  both  simultaneous  ;  «,  a  handle  work- 
ing a  small  eccentric  acting  upon  the  rod 
d,  in  such  a  manner  as  to  open  or  close 
the  switches  c,  c,  and  consequently  guide 
the  wheels  either  upon  the  continuous  or 
diverging  line  as  may  be  required.  (See 
Railway.) 

SYMPIESOMETER.  A  kind  of  ba- 
rometer, contrived  by  Mr.  Adie  of  Edin- 
burgh, for  measuring  the  weight  of  the 
atmosphere  by  the  compression  of  a 
column  of  gas.  It  consists  of  a  glass 
tube  about  18  inches  long,  having  the 
lower  end  bent  up  like  the  tube  of  the 
wheel  barometer,  each  end  being  termi- 
nated by  an  elongated  bulb.  The  upper 
end  is  hermetically  sealed,  but  the  lower 
end  is  left  open.  The  upper  part  of  the 
tube  is  filled  with  hydrogen  gas,  and  the 
lower  part  with  some  fixed  oil.  The  pres- 
sure of  the  atmosphere  is  exerted  upon 
the  surface  of  the  oil,  which  is  exposed 
to  it  in  the  turned  up  open  end  of  the 
tube.  This  pressure  causes  the  oil  to 
stand  at  a  certain  height  in  the  tube,  and 
to  produce  a  certain  compression  in  the 
column  of  hydrogen  gas.  As  the  atmos- 
pheric pressure  becomes  greater,  the  oil 
will  rise,  and  the  gas  will  be  compressed 
into  less  space.  The  change  in  the  bulk 
of  the  gas  caused  by  a  change  in  the  at- 


628 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tag 


mosphsric  pressure  is  measured  by  a 
scale.  The  sympiesometer  is  a  useful 
instrument,  but  inferior  in  accuracy  to 
the  common  barometer. 

SYPHON,  or  crane,  is  a  bent  tube  with 
one  leglonger  than  the  other,  so  that  its 
orifice  may  be  lower ;  if  then  the  air  is 
sucked  out  the  short  leg,  being  in  a  fluid 
will  continue  to  flow  till  the  surface  is 
below  the  level  of  the  orifice  ;  or  if  the 
syphon  is  filled  before  it  is  immersed  at 
the  short  end,  the  fluid  will  run  out  at 
the  lower  end,  and  will  be  followed  as 
before.  The  syphon,  for  many  domestic 
purposes,  is  most  convenient. 

Syphons  are  used  to  raise  water  over 
banks. 

Mr.  O.  P.  Laird,  a  farmer  at  Oneida 
Castle,  N.  Y.,  has  a  syphon  in  successful 
operation  which  conveys  water  to  his 
house,  a  distance  of  sixty-six  rods,  over  a 
ridge  of  land  sixteen  feet  high,  in  half 
inch  lead-pipe,  No.  1.  It  is  discharged 
four  feet  lower  than  the  surface  of  the 
water  in  the  spring,  and  at  the  rate  of 
eighteen  gallons  per  hour. 

Syphons  will  continue  to  work,  provi- 
ded they  are  perfectly  tight,  and  if  there 
is  a  moderate  amount  of  fall  from  the 
surface  of  the  water  in  the  well  to  the 
place  of  delivery.  Water  is  raised  in  a 
syphon  on  the  same  principle  that  it  is 
in  the  suction  pump,  and  may  be  elevat- 
ed to  the  same  higlit,  to  wit,  thirty-two 
feet.  The  objection  to  raising  it  very 
high  in  a  syphon  is,  that  air  separates 
from  water  when  thus  raised,  and  the 
higher  it  is  drawn  the  more.  It  is  essen- 
tial that  there  should  be  sufficient  cur- 
rent to  carry  out  this  air  as  fast  as  it  is 
evolved,  otherwise  it  would  accumulate 
and  stop  the  water.  Four  feet  of  fall  an- 
swers the  purpose.  Every  thing  depends 
on  the  perfect  air-tightness  of  the  pipe. 

SYRINGE.  In  hydraulics,  a  machine 
consisting  of  a  small  cylinder  with  an 
air-tight  piston  or  sucker,  which  is  mov- 
ed up  and  down  in  it  by  means  of  a  han- 
dle. The  lower  end  of  the  cylinder  ter- 
minates in  a  small  tube,  through  which  a 
fluid  is  forced  into  the  body  of  the  cylin- 
der by  the  atmospheric  pressure  when 
the  handle  is  drawn  up,  and  then  expel- 
led in  a  small  jet  by  pushing  the  handle  in 
the  opposite  direction.  The  syringe  acts 
on  the  principle  of  the  sucking  pump. 
The  syringe  is  also  used  as  a  pneumatic 
machine  for  condensing  or  exhausting  the 
air  in  a  close  vessel,  but  for  this  purpose 
it  must  be  furnished  with  two  valves.  In 
the  condensing  syringe,  the  valves  open 
downwards  and  close  upwards;  in  the 


exhausting  syringe  they  are  closed  down- 
wards and  opened  upwards.  (See  Am 
Gun  and  Am  Pump.) 

TACAMAHAC.  A  resin  obtained 
from  the  Faguru  octandra,  a  tree  which 

frows  in  Mexico  and  the  West  Indies, 
t  occurs  in  yellowish  pieces,  of  a  strong 
smell,  and  a  bitterish  aromatic  taste. 
That  from  the  island  of  Madagascar  has 
a  greenish  tint. 

TACHOMETER.-  A  contrivance  in- 
vented for  the  purpose  of  indicating 
minute  variations  in  the  velocity  of  ma- 
chines. When  a  vessel  containing  a  fluid 
is  whirled  rapidly  round  a  vertical  axis, 
the  centrifugal  force  produced  by  the 
whirling  motion  causes  the  fluid  to  re- 
cede from  the  axis,  and  to  rise  on  the 
sides  of  the  vessel,  so  that  the  surface  of 
the  fluid  assumes  a  concave  parabolic 
form ;  and  the  distance  to  which  the  cen- 
tre of  the  surface  falls  below  its  original 
level  is  proportionate  to  the  velocitv  of 
rotation,  and  subject  to  corresponding 
variations.  Any  method,  therefore,  of 
measuring  or  rendering  visible  the  de- 
pression of  the  central  surface  will  indi- 
cate the  variations  of  velocity.  The 
method  usually  adopted  is  the  following : 
A  glass  tube  open  at  both  ends,  and  ex- 
panding at  one  extremity  into  a  bell,  is 
immersed  with  its  wider  end  in  mercury 
contained  in  a  cup.  The  tube  is  so  sus- 
pended as  to  be  unconnected  with  the 
cup.  This  tube  is  then  filled  to  a  certain 
height,  with  spirits  tinged  with  some 
coloring  matter,  to  render  it  easily  ob- 
servable. The  cup  is  attached  to  a  spin- 
dle turned  by  the  machine.  Now  as  the 
cup  is  whirled  round  by  the  spindle,  the 
level  of  the  mercury  in  the  bell  falls,jind 
the  spirit  therefore  descends  in  the  tube. 
As  the  motion  is  continued,  every  change 
of  velocity  causes  a  corresponding:  change 
in  the  level  of  the  mercury,  and  conse- 
quently also  in  the  height  of  the  spirits 
in  the  tube  ;  and  as  the  capacity  or  the 
bell  is  much  greater  than  that  of  the 
tube,  a  very  small  change  in  the  level  of 
the  mercury  causes  a  considerable  change 
of  the  heigrht  of  the  spirits  in  the  tube. 

TAFFETA.  A  light  silk  fabric,  with 
a  considerable  lustre  or  g-loss. 

TAFIA.    A  variety  of  rum. 

TAGLIA.  In  mechanics,  the  name 
given  to  a  particular  combination  of  pul- 
leys. The  taglia  consists  of  a  system  of 
fixed  pulleys  collected  in  one  common 
block,  and  also  of  a  svstem  of  movable 
pulleys  in  a  separate  block,  to  which  the 
weight  is  attached,  with  one  string  going 
j  round  all  the  pulleys,  and  having  one  of 


tan] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


629 


its  ends  fixed  to  a  point  in  the  system, 
and  the  other  end  going  from  one  of  the 
fixed  pulleys  drawn  by  the  power.  Some- 
times several  taglias  are  combined,  so 
that  one  acts  upon  the  other ;  the  system 
is  then  a  compound  taglia.  (See  Pulley.) 
TALC.  A  mineral  genus,  which  is 
divided  into  two  species,  the  common 
and  the  indurated.  The  first  occurs  mas- 
sive, disseminated  in  plates,  imitative, 
or  crystallized  in  small  six-sided  tables. 
It  is  splendent,  pearly,  or  semi-metallic, 
translucent,  flexible,  but  not  elastic.  It 
yields  to  the  nail ;  spec.  grav.  2-77.  Be- 
fore the  blowpipe,  it  first  whitens  and 
then  fuses  into  an  enamel  globule.  It 
consists  of —  silica,  62  ;  magnesia,  27 ; 
alumina,  1*5 ;  oxide  of  iron,  8-5  ;  water, 
6.  Klaproth  found  2i  per  cent,  of  pot- 
ash in  it.  It  is  found  in  beds  of  clay- 
slate  and  mica-slate,  in  New  England. 
It  is  an  ingredient  in  rouge  for  the  toilette, 
communicating  softness  to  the  skin.    It 

Sives  the  flesh  polish  to  soft  alabaster 
gures,  and  is    also  used  in  porcelain 
paste. 

The  second  species,  or  talc-slate,  has  a 
greenish-gray  color ;  is  massive,  with 
tabular  fragments,  translucent  on  the 
edges,  soft,  with  a  white  streak ;  easily 
cut  or  broken,  but  is  not  flexible  ;  and 
has  a  greasy  feel.  It  occurs  in  the  same 
localities  as  the  preceding.  It  is  employ- 
ed in  the  porcelain  and  crayon  manufac- 
tures ;  as  also  as  a  crayon  itself,  by  car- 
penters, tailors,  and  glaziers. 

TALLOW.  The  concrete  fat  of  qua- 
drupeds and  man.  That  of  the  ox  con- 
sists of  76  parts  of  stearine,  and  24  of 
oleine  ;  that  of  the  sheep  contains  some- 
what more  stearine.    (See  Fat  and  Stea- 

KINE.) 

The  Tallyw-tree  is  a  native  of  China, 
and  belongs  to  the  natural  family  ewphor- 
biaceat.  At  the  close  of  the  season  the 
leaves  turn  bright-red,  and,  as  the  cap- 
sules fall  off,  leaving  the  pure  white  seeds 
suspended  to  filaments.  From  a  remote 
period,  this  tree  has  furnished  the  Chi- 
nese with  the  material  out  of  which  they 
make  their  candles.  The  capsules  and 
seeds  are  crushed  together,  and  boiled ; 
the  fatty  matter  is  skimmed  as  it  rises, and 
condenses  on  cooling.  The  candles  made 
of  this  substance  are  very  white ;  and 
red  ones  are  manufactured  with  the  ad- 
dition of  vermilion.  It  is  now  cultivated 
in  the  vicinity  of  Charleston  and  Savan- 
nah with  great  promise. 

TAMPING.  A  term  used  by  miners 
to  express  the  filling  up  of  a  hole  bored 
in  a  rock  for  the  purpose  of  blasting. 


TANK.  In  gardening,  a  cistern  or 
reservoir,  made  of  stone  or  timber,  or 
some  other  material,  used  in  collecting 
and  preserving  water  during  a  scarcity  or 
drought.  Tanks  are  sometimes  built  in  the 
ground,  and  lined  with  lead  or  cement. 

TANNER'S  BARK.  The  bark  of  oak, 
chesnut,  willow,  larch,  and  other  trees, 
which  abounds  in  tannin,  and  is  used  for 
preparing  leather.  After  being  exhaust- 
ed of  the  tanning  principle  by  being 
chopped  into  small  pieces,  or  bruised, 
or  steeped  in  water,  it  is  laid  up  in  heaps 
to  dry,  and  sold  to  gardeners  for  the  pur- 
pose of  producing  artificial  heat  by  fer- 
mentation in  pits  or  beds,  in  bark-stoves 
or  ether  out-houses,  or  pits.   (See  Stove.) 

TANNIC  ACID.  This  term  has  been 
especially  applied  to  a  substance  obtained 
by  Pelouze  by  acting  upon  bruised  galls 
by  common  ether ;  it  is  a  white  uncrys- 
talline  powder,  very  astringent,  little  so- 
luble in  water,  and  reddening  litmus. 
When  moistened  and  exposed  to  air  it 
becomes  converted  into  gallic  acid.  It  is 
extremely  astringent,  and  appears  to  be 
the  active  principle  of  tanning  substan- 
ces (tannin)  in  general.  Its  equivalent, 
deduced  from  the  analysis  of  the  iieutral 
tannates,  appears  to  be  426.  Its  ultimate 
elements  are  30  atoms  of  carbon,  18  of 
hydrogen,  and  24  of  oxygt   . 

TANNIN.  The  pure  astringent  prin- 
ciple of  vegetables,  upon  which  their 
power  of  converting  skin  into  leather  de- 
pends. Its  leading  character  is  its  pro- 
perty of  producing  a  dense  whitish  pre- 
cipitate in  a  strong  solution  of  animal 
jelley,  such,  for  instance,  as  isinglass.  It 
may  be  obtained  tolerably  pure  by  in- 
fusing bruised  grape  seeds  in  cold  water ; 
or  more  circuitously  by  adding  acetate 
of  copper  to  filtered  infusion  of  galls, 
washing  the  precipitate,  and  decompos- 
ing it  (diffused  through  water)  by  sul- 
phurated hydrogen.  On  evaporating  its 
solution,  it  is  obtained  as  a  pale  yellow 
extract,  of  a  strong  astringent  taste.  The 
action  of  astringents  upon  persalts  of 
iron  has  given  rise  to  its  distinction  into 
two  varieties  ;  the  first  changing  them  to 
deep  blue  or  black,  the  second  to  green. 
The  tan  of  galls,  oak  bark,  grape  seeds, 
&c.,  possesses  the  former  property;  that 
of  catechu  and  tea  the  latter. 

By  digesting  powdered  charcoal  in  ni- 
tric acid,  and  carefully  evaporating  the 
solution  so  obtained,  Mr.  Hatchett  suc- 
ceeded in  procuring  a  brown  substance 
of  an  astringent  taste,  and  precipitating 
solution  of  gelatine,  which  he  terms, 
therefore,  artificial  tan. 


630 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tan 


TANNING.  The  formation  of  leather 
from  skins. 

It  is  founded  on  the  fact,  that  the  tan- 
nin principle  precipitates  gelatine,  or 
animal  jelly,  in  an  insoluble  state.  Tan- 
nin also  precipitates  the  sulphate  of  iron, 
lying  between  the  hair  and  the  skin.  By- 
strong  extracts  of  the  bark,  Seguin  tan- 
ned calf  in  1  day,  and  oxhides  in  7  or  8 
days.  1  lb.  of  catechu  is  equal  to  2i  galls, 
3  sumach,  8i  oak-bark,  7i  willow-bark, 
and  18  elm-bark. 

The  outer  coating  of  the  hemlock,  and 
various  species  of  the  oak  are  the  princi- 

Eal  materials  generally  used  in  the  United 
states.  The  former  for  the  great  body 
of  sole  leather,  the  latter,  for  the  various 
harness  and  upper  leather.  The  trees 
are  felled  in  the  season  when  the  sap  is 
ascending,  from  1st  May  to  1st  Septem- 
ber, though  usually  only  from  May  15th 
to  August ;  and  the  bark  is  easily  peeled 
off  in  sheets  of  any  required  length,  but 
usually  four  feet  long.  It  should  be  suf- 
fered to  lie  with  the  inner  surface  expos- 
ed to  the  sun  one  or  two  clear  days,  to 
dry  up  the  sap  on  that  surface,  when  it 
should  be  gathered  into  piles  of  a  square 
form,  in  a  dry  place,  on  poles  above  the 
ground,  and  be  protected  by  large  pieces, 
laid  carefully  on  the  top  of  the  pile. 
The  body  only  is  peeled  in  this  country, 
except  the  larger  branches  of  the  oak  ; 
while  in  England  the  small  limbs,  and 
even  twigs,  all  that  will  peel,  are  saved, 
and  thought  to  be  stronger  than  the  body 
bark.  Thirty  days  of  dry  weather  will 
cure  the  bark  sufficiently  for  use.  But 
in  a  large  business  it  is  drawn  to  a  road 
side,  after  harvest,  and  piled  in  like  man- 
ner, and  is  suffered  to  remain  until  fall 
or  winter,  when  it  is  drawn  into  the  tan- 
nery, and  stored  in  large  piles  in  the 
open  air  or  in  cheap  open  sheds,  and 
taken  into  the  tannery  as  wanted.  At 
the  North  this  is  usually  done  in  winter, 
which  makes  good  sleighing,  almost  as 
important  to  the  tanner  as  bright  skies 
in  June  and  July.  Chemical  tests  give 
to  hemlock  bark  only  3f  to  6  per  cent, 
tannin.  American  oak  not  more  than 
half  as  much,  while  English  hedgerows 
is  16  per  cent.  Various  other  foreign 
substances  contain  tannin.  Valonia,  of 
Turkey,  or  the  acorn  cup  and  ball,  gath- 
ered in  a  green  state,  is  the  favorite  in 
England,  and  it  is  believed  that  the  great 
burr  oak  of  the  Middle  States  yield  an 
annual  crop  of  the  same  material,  which 
if  gathered  would  be  sufficient  for  all  the 
tanning  of  America,  and  save  the  destruc- 
tion of  our  noble  forests  now  going  on  at 


the  North  so  rapidly.  The  strongest  ar- 
ticle known  is  kutch,  imported  from  the 
East  Indies,  evidently  an  extract  boiled 
down  to  salts,  which  contain  about  55 
per  cent,  pure  tan.  It  is  too  expensive 
for  common  use  in  this  country,  but  is 
much  used  in  England,  in  liquors  for 
heavy  stock.  It  is  computed  that  for 
every  cord  of  hemlock  bark  four  trees 
are  peeled,  and  one  cord  will  tan  five 
hides.  If  the  whole  quantity  of  leather 
is  1,000,000  sides,  200,000  trees  are  an- 
nually destroyed  to  furnish  the  bark. 

The  skins  of  animals  are  immersed, 
for  several  days,  or  even  weeks,  in  water 
with  bark,  mostly  of  oak  or  larch  ;  and 
other  astringent  substances,  as  terra  ja- 
ponica,  are  employed,  which  shortens  the 
time,  but  renders  the  substance  more 
hard  and  brittle.  Another  method  is  by 
tawing.  They  are  left  to  soak,  for  six 
weeks,  in  water,  with  fresh  slaked  lime, 
changed  twice,  rinsed,  again  soaked  in 
water  mixed  with  wheat  bran,  until 
they  float,  but,  when  beaten  down,  do 
not  rise  again.  The  bran  is  then  scraped 
off,  and  a  liquid  paste  is  prepared,  for 
100  sheep-skins,  8  lbs.  of  alum  and  8 
lbs.  of  salt  are  dissolved,  in  warm  water, 
and  added  to  20  lbs.  of  fine  wheat  flour 
and  96  yolks  of  eggs.  A  ladle  full  of  this 
paste  is  put  into  a  trough  of  warm  water, 
in  which  12  skins  remain  for  some  time, 
and  are  then  pulled  and  stretched ;  and 
this  is  repeated  twice.  They  are  then 
left  six  days,  and  afterwards  quickly 
dried. 

Slow  tanning  makes  leather  softer  and 
stronger. 

Time  and  labor  are  both  materially 
reduced,  and  the  quantity  and  weight  of 
the  leather  increased,  by  the  substitution 
of  water  power  for  manual  labor,  in 
many  of  the  most  laborious  parts  of  the 
process;  viz.  to  soften  and  cleanse  the 
hide  preparatory  to  the  bark  being  appli- 
ed to  it ;  to  grind  the  bark ;  to  move 
pumps  for  transferring  the  decoction  of 
the  bark  from  one  vat  to  another  (much 
of  which  is  necessary  to  be  done  daily  in 
an  extensive  tannery),  and  to  roll  the 
leather  preparatory  to  its  being  sent  to 
market ;  also  the  least  possible  quantity 
of  lime  is  now  used  to  facilitate  getting 
off  the  hair.  This  has  been  found  greatly 
to  add  to  the  weight  and  quality  of  the 
leather.  The  application  of  heat  to  bark, 
in  leaches,  is  found  to  be  very  important, 
and  more  particularly  the  application  of 
the  decoction  (usually  termed  liqvor)  to 
the  hide,  rather  than  "the  bark. 

Tanning  by  Bilberry  or  Wliartleberry. 


tea] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


631 


3*  lbs.  of  tins  tan  dress  1  lb.  of  leather, 
while  6  lbs.  are  required  from  the  oak, 
and  tanners  also  gain  four  months. 

After  tanning,  the  currying  takes  plaee. 
This  consists  in  removing  all  excrescences, 
soaking  and  trampling,  covering  with  oil, 
and  pummelling,  to  produce  pliancy. 
They  are  then  colored,  white  with 
white-lead,  black  with  a  solution  of  iron, 
and  a  second  of  soot,  vinegar,  and  gum. 

TANTAL1TE,  or  COLUMBITE.  The 
ferruginous  oxide  of  columbium.  It  oc- 
curs in  small  masses,  and  in  octahedral 
crystals.  It  has  been  found  in  Finland 
and  in  this  country. 

TAPESTRY.  Is  an  ornamental  figured 
textile  fabric  of  worsted  or  silk,  for  lining 
the  walls  of  apartments ;  of  which  the 
most  famous  is  that  of  the  Gobelins 
Royal  Manufactory,  near  Paris. 

TAPIOCA.  A  modification  of  starch, 
partially  converted  into  gnm,  by  heating 
and  stirring  cassava  upon  iron  plates. 
(See  Cassava  and  Starch.) 

TAR.  The  viscid,  brown-black,  resino- 
oleaginons  compound,  obtained  by  distil- 
ling wood  in  close  vessels,  or  in  ovens  of 
a  peculiar  construction.  (See  Charcoal, 
Pitcoal,  and  Pyroligneous  Acid.)  Ac- 
cording to  Reichenbach,  tar  contains  the 
peculiar  proximate  principles,  paraffine, 
eupion,  creosote,  picamar,  pittacal,  besides 
pyrogenous  resin,  or  pyretine,  pyroge- 
nons  oil,  or  pyroleine,  and  vinegar.  The 
resin,  oil,  and  vinegar  are  called  empy- 
reumatic,  in  common  language. 

TARTAR,  called  also  argal  or  argol, 
is  the  crude  bitartrate  of  potassa,  which 
exists  in  the  juice  of  the  grape,  and  is 
deposited  from  wines  in  their  fermenting 
casks,  being  precipitated  in  proportion 
as  the  alcohol  is  formed,  in  consequence 
of  its  insolubility  in  that  liquid.  There 
are  two  sorts  of  argal  known  in  com- 
merce, the  white,  and  the  red  ;  the  form- 
er, which  is  of  a  pale-pinkish  color,  is  the 
crust  let  fall  by  white  wines ;  the  latter 
is  a  dark-red,  from  red  wines. 

TARTARIC  ACID.  The  acid  of  tar- 
tar. This  acid  is  contained  in  grape 
juice,  and  in  tamarinds  and  several  other 
fruits.  It  is  usually  obtained  from  puri- 
fied tartar:  4  parts  of  powdered  tartar 
and  1  of  chalk  are  mixed  in  hot  water, 
and  the  white  powder  which  subsides 
(tartrate  of  lime)  is  decomposed  by  dilute 
sulphuric  acid,  which  combines  with  the 
lime  to  form  sulphate  of  lime,  and  the 
tartaric  acid  being  liberated  is  obtained 
by  evaporation.  When  pure  it  forms 
white  crystals,  composed  of  one  equiva- 
lent of  dry  acid,  and  one  of  water  (66+9 


=75).  The  anhydrous  tartaric  acid,  as  it 
exists  in  the  dry  tartrates  (tartrate  of 
lead,  for  instance),  is  composed  of 

Atoms.  Equiv. 

Carbon 4  24  36  3G 

Hydrogen 2  2  303 

Oxygen 5  40  6061 

1  66         100-00 

TAWING.  The  art  of  preparing  cer- 
tain kinds  of  leather  by  imbuing  the 
skins  with  saline,  oily,  and  other  mat- 
ters.    (See  Taxnino.) 

TEA.  The  leaves  of  the  Thea  officinalis. 
This  plant  resembles  the  Camellia,  but 
its  leaves  and  flowers  are  much  smaller. 
It  is  five  or  six  feet  high,  and  is  an  ever- 
green. It  is  a  native  of  China  and 
japan,  and  has  been  cultivated  therefor 
centuries  ;  was  unknown  in  Europe  till 
the  middle  of  the  seventeenth  century, 
yet  is  now  become  of  so  much  import- 
ance as  to  employ  50.000  tons  of  shipping 
in  its  transportation  from  Canton.  It  is 
cultivated  in  all  parts  of  Chin.,  oven  at 
Pekin,  which  has  the  same  latitude  as 
Philadelphia.  The  plants  require  little 
care  till  the  third  year,  when  they  are  fit 
for  gathering.  In  seven  years  the  plants 
attain  the  height  of  six  feet.  The  leaves 
are  plucked  otf  one  by  one  with  many 
precautions,    and   from    six   to    sixteen 

fxmnds  per  day  are  plucked.  The  first 
eaves  are  gathered  at  the  end  of  the 
winter,  when  the  leaves  are  young  and 
tender ;  the  second  gathering  is  in  the 
beginning  of  spring,  when  the  leaves  are 
of  nearly  their  lull  size;  the  last  gather- 
ing takes  place  in  midsummer.  These 
are  of  inferior  quality.  There  are  two 
varieties  of  tea — the  Thea  viridis  and 
Thea  boliea.  Formerly  it  was  believed 
that  all  the  green  tea  was  gathered  from 
T.  viridis,  but  this  is  now  known  not  to 
be  so,  there  being  a  green  tea  district 
where  the  leaves  are  gathered  from  both 
varieties  of  trees  indiscriminately.  The 
names  given  in  commerce  are  unknown 
to  the  Chinese.  When  the  leaves  are 
gathered  they  are  dried  in  houses  con- 
taining small  furnaces,  having  an  iron 
pan  on  the  top  of  each.  The  leaves 
are  rolled  on  tables  covered  with  mats, 
and  then  a  few  pounds  are  laid  on  the 
iron  pan  heated ;  the  workman  shifts 
them  with  his  bare  hands  lest  they  should 
burn.  When  he  cannot  bear  the  heat 
longer  he  transfers  the  tea  to  the  mats  ; 
they  are  then  rolled  again  on  the  pan 
till  they  are  twisted:  it  is  repeated  fre- 
quently before  the  tea  is  stored,  so  that 
no  moisture  may  remain  in  it.     The  dif- 


6S2 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[TEA 


ferent  kinds  of  black  and  green  differ 
not  only  in  soil  and  climate  but  in  after 
treatment.  The  color  of  green  tea  is 
due  to  an  admixture  of  gypsum  and 
Prussian  blue,  which  is  dusted  over  it  in 
the  pans. 

The  leaves  of  tea  have  little  or  no 
smell,  and  they  derive  their  fragrance  by 
mixing  the  leaves  of  Olea  fragrans  and 
Camellia  sesanqua,  also  of  Polegala  the- 
zans,  and  of  Rhamnus  thezans. 

China  tea  does  not  turn  black  by  wa- 
ter, impregnated  with  sulphuretted  hy- 
drogen ^as ;  nor  give  a  blue  tinge  to 
spirit  of  hartshorn.  The  infusion,  amber 
colored,  is  not  reddened  by  sulphuric 
acid.  The  leaves,  separate  or  mixed,  of 
speedwell,  wild  germander,  black  cur- 
rants, mock  orange,  purple-spiked  wil- 
low herb,  sweet-briar,  cherry-tree,  haw- 
thorn, bramble,  sloe,  are  substituted  for 
tea  by  dealers.  Foreigners  use  a  variety 
of  plants,  instead  of  Chinese  tea,  and 
Zenopormtthea  Sinensis  is  cultivated  in 
France  as  a  substitute.  Japanese  camellia 
leaves  are  frequently,  by  the  Chinese, 
mixed  with  those  of  tea. 

Russian  tea,  is  leaves  of  saxifrage, 
winter  green,  white  virgin's  bower, 
bird  cherry,  drop  worts,  common  elm, 
male  fern,  and  dog-rose. 

The  active  principle  of  tea  is  believed 
to  be  Theme,  a  substance  found  also  in 
coffee  and  in  the  ilex  paraguyaensis,  a 
native  of  Brazil. 

Mr.  Stenhouse  prepares  theine  by  pre- 
cipitating a  decoction  of  tea  with  solu- 
tion of  acetate  of  lead,  evaporating  the 
filtered  liquor  to  a  dry  extract,  and  ex- 
posing this  extract  to  a  subliming  heat 
in  a  shallow  iron  pan,  whose  mouth  is 
covered  flatly  with  porous  paper  luted 
round  the  edges,  as  a  filter  to  the  vapor, 
and  surmounted  with  a  cap  of  compact 
paper,  j.s  a  receiver  to  the  crystals.  In 
this  wav  he  obtained,  at  a  maximum, 
only  1-87  from  100-00  of  tea.  But  M. 
Peligot,  from  the  quantity  of  azote 
amounting  to  about  6  per  cent.,  which 
he  found  in  the  tea  leaves,  being  led  to 
believe  that  much  more  theine  existed  in 
them  than  had  hitherto  been  obtained, 
adopted  the  following  improved  process 
of  extraction.  To  the  hot  infusion  of 
tea,  snbacetate  of  lead  and  then  ammonia 
were  added;  through  the  filtered  liquor 
a  current  of  sulphufettedi  hydrogen  was 
passed  to  throw  down  ail  the  lead,  and 
the  clear  liquid  being  evaporated  at  a 
gentle  heat  afforded,  on  cooling,  an 
abundant  crop  of  crystals.  By  re-evapo- 
ration of  the  mother  liquor,  more  crys- 


tals were  procured,  amounting  altogether 
to  from  5  to  6  out  of  100  of  tea. 
The  composition  of  theine  may  be  re- 

E resented  by  the  chemical  formula,  C8, 
i5,  N2,  O* ;  whence  it  appears  to  con- 
tain no  less  than  29  per  cent,  of  nitrogen 
or  azote. 

Peligot  found,  on  an  average,  in  100 
parts  of — 

Parts  soluble  in  boiling  Water. 

Dried  black  teas 432 

Green  teas 47-1 

Black  teas,  as  sold 384 

Green  teas,  ditto 43  4 

Tea,  by  Mulder's  general  analysis,  has 
a  very  complex  constitution ;  100  parts 
contain — 

Green.     Black. 
Essential  oil  (to  which  the  flavor 

isdue) 079  0  60 

Chlorophyle  (half-green  matter).  2  22  184 

Wax 028 

Resin 222  3  64 

Gum 8-56  7.28 

Tannin 17  80  1288 

Theine 043  046 

Extractive  matter 2280  19  88 

Do.           dark  colored  ..  —  148 
Coloring  matter  separable  by  mu- 
riatic acid 23.60  19.12 

Albumine 3  00  280 

Vegetable  fibre 1708  2832 

Ashes 556  524 

By  the  enterprise  of  Dr.  Junius  Smith, 
the  cultivation  of  the  tea-plant  in  the  Unit- 
ed States  has  been  introduced,  it  having 
recently  been  grown  in  South  Carolina,  un- 
der circumstances  which  would  indicate 
that  the  question  of  its  success  may  soon 
be  decided.  Partial  attempts  have  before 
been  made  by  planting  a  tew  seed.  But 
Dr.  Smith  has  brought  out  plants  of 
seven  years  growth.  In  a  letter  respect- 
ing this  fact,  he  says,  that  on  the  15th 
and  16th  of  December,  1848,  he  planted 
out  at  Greenville,  South  Carolina,  the  tea 
seed  which  he  carried  with  him,  and 
went  to  work  preparing  the  ground  for 
the  reception  of  his  tea" plants,  which  he 
adds,  "  was  no  slight  labor  in  this  hilly, 
rocky,  stumpy,  rooty  domain."  His 
packages  of  plants  arrived  some  time 
after  him,  and  on  opening  them,  he  says 
several  of  the  plants  were  in  full  bloom, 
with  their  leaves  fresh  and  green,  as  if 
growing  in  China  ;  others  with  the  blos- 
som bud  just  showing  its  ivory  breast 
ready  to  develope  all  its  beauties. 

"You  may  say,  therefore,  that  the  tea 

Slant  is  in  blossom  in  South  Carolina. 
In  Tuesday,  the  26th  of  December,  he 
planted  out  the  first  tea  shrubs  ever  cul- 
tivated in  the  tfnited  States  for  agricul- 
tural and  commercial  purposes.  Out  of 
five  hundred  plants  he  found  five  which 


tel] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


633 


he  thought  of  doubtful  vitality,  and 
these  he  transferred  to  the  infirmary, 
and  subjected  them  to  vigilant  nurs- 
ing." 

There  is  a  large  tract  of  our  country 
which  falls  within  the  latitude  in  which 
tea  is  most  successfully  raised  in  China. 
In  Dr.  Smith's  pamphlet  on  the  subject, 
he  says  it  grows  there  most  luxuriantly 
between  the  parallels  of  20°  and  45° 
north  latitude.  "In  the  geographical 
and  physiological  views  of  that  portion 
of  the  United  States,  presumed  to  be 
best  adapted  to  the  growth  of  the  tea 
plant,"  he  says  :  "  We  may  assume  the 
latitude  of  40°  as  the  northern,  and  the 
Gulf  of  Mexico  as  the  southern  limits  of 
the  tea  growth.1'  That  the  tea  plant  can 
grow  in  our  country  is  now  a  settled  fact ; 
but  the  high  price  of  labor  will  retard  its 
introduction  into  market,  until  machinery 
here  can  compete  with  the  enormously 
low  price  of  labor  in  China. 

TEAK  is  one  of  the  largest  trees 
known,  and  interesting  from" the  proper- 
ties of  the  wood.  It  is  considerea  supe- 
rior to  all  others  for  ship-building,  and 
is  extensively  used  in  the  East  in  houses 
and  temples.  It  is  now  planted,  with  a 
view  to  timber,  in  Bengal.  The  leaves 
furnish  a  purple  dye,  employed  on  cot- 
tons and  silks. 

TEASEL.  The  teasel  (dipsacus  fullo- 
num)  throws  up  its  heads  in  July  and 
August ;  these  are  cut  from  the  plant  by 
hand  with  a  peculiarly  formed  knife,  and 
then  fastened  to  polesfor  drying.  When 
dry,  they  are  picked  and  sorted  into  bun- 
dles. 

The  use  of  heads  of  teasel  is  to  draw 
out  the  ends  of  the  wool  from  the  manu- 
factured cloth,  so  as  to  bring  a  regular 
pile  or  nap  upon  the  surface,  free  from 
twistings  and  knottings,  and  to  comb  off 
the  coarse  and  loose  parts  of  the  wool. 
The  head  of  the  true  teasel  is  composed 
of  incorporated  flowers,  each  separated  by 
a  long,  rigid,  chaffy  substance,  the  ter- 
minating point  of  which  is  furnished 
with  a  fine  hook.  Several  of  these  heads 
are  fixed  in  a  frame,  and  with  this  the 
surface  of  the  cloth  is  brushed,  until  all 
the  ends  are  drawn  out,  the  loose  parts 
combed  off,  and  the  cloth  ceases  to  yield 
impediments  to  the  free  passage  of  the 
wheel  or  frame  of  teasels.  Should  the 
hook  of  the  chaff,  when  in  use,  become 
fixed  in  a  knot,  or  find  sufficient  resist- 
ance, it  breaks,  without  injuring  or  con- 
tending with  the  cloth ;  and  care  is  taken, 
by.  successive  applications,  to  draw  the 
impediment  out.  The  dressing  of  a  piece 
27* 


of  cloth  consumes  from  1,500  to  2,000 
heads.  They  are  used  repeatedly  in  the 
different  stages  of  the  process ;  but  a 
piece  of  fine  cloth  generally  breaks  this 
number  before  it  is  finished.  There  is  a 
consumption  answering  to  the  proposed 
fineness — pieces  of  the  best  kinds  requir- 
ing 150  or  200  runnings  up. 

They  are  now  being  gradually  super- 
seded everywhere  by  machinery. 

TECTORIUM  OPUS.  In  architecture, 
the  plasterers'  work  used  on  ceilings  and 
interior  walls :  it  was  a  composition  of 
lime  and  sand,  and  differed  from  stucco, 
which  was  called  albarium  opus.     Great 

Eains  were  taken  to  prevent  its  cracking, 
y  crossing  layers  ot  reed  upon  it  coated 
with  argillaceous  earth  previous  to  coating 
it  with  paint. 

TELEGRAPH.  The  name  given  to  a 
mechanical  contrivance  for  the  rapid  com- 
munication of  intelligence  by  signals.  Of 
late  years,  the  term  semaphore  has  been 
introduced  by  the  French,  and  frequent- 
ly adopted  by  English  writers. 

Although  the  art  of  conveying  intelli- 
gence by  signals  was  practised  in  the  ear- 
liest ages,  and  is  known  even  to  the  ru- 
dest savages ;  and  although  its  impor- 
tance is  not  only  obvious,  but  continually 
felt  wherever  civilization  is  established^ 
it  has  been  allowed  to  remain  in  its  orig- 
inal state  of  imperfection  down  almost  to 
our  times.  The  first  description  of  a  tele- 
graph universally  applicable  was  given 
by  Dr.  Hooke.  The  method  which  he 
proposed,  for  it  was  not  carried  into  prac- 
tice, consisted  in  preparing  as  many  dif- 
ferent shaped  figures,  formed  of  deal — 
for  example,  squares,  triangles,  circles, 
&c,  as  there  are  letters  in  the  alphabet, 
and  exhibiting  them  successively,  in  the 
required  order,  from  behind  a  screen. 

The  first  telegraph  actually  used  was 
the  invention  of  Chappe.  It  consisted  of 
a  beam  which  turned  on  a  pivot  in  the 
top  of  an  upright  post,  having  a  movable 
arm  at  each  of  its  extremities ;  and  each 
different  position  in  which  the  beam  and 
its  two  arms  could  be  placed  at  angles  of 
45°  afforded  a  separate  signal,  which 
might  represent  a  letter  of  the  alphabet, 
or  have  any  other  signification  that  might 
be  agreed  upon.  In  1803,  the  French 
erected  semaphores  along  their  whole  line 
of  coast,  formed  of  an  upright  post,  car- 
rying two,  or  sometimes  three  beams  of 
wood,  each  turning  on  its  own  pivot,  one 
above  the  other.  In  1807,  Captain  (now 
General)  Pasley  published  his  Polygram- 
matic  Telegraph,,  which  was  adopted  in 
that  year  by  the  Admiralty  instead  of 


634 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tec 


sU- 


the  shutter  telegraph,  and  has  continued 
in  use  ever  since. 

For  day  signals,  the  telegraph  consists 
of  an  upright  post  of  sufficient  height, 
with  two  arms  movable  on  the  same 
pivot  on  the  top  of  it,  and  a  short  arm, 
called  the  indicator,  on  one  side ;  as  in 
the  annexed  figure.  Each  arm  can  ex- 
hibit the  seven  posi- 
tions, 1,  2,  3,  4,  5,  6,  7, 
besides  the  position 
called  the  stop,  which 
points  vertically  down- 
wards, and  is  hid  by 
the  post.  In  order  to 
show  the  number  of  sig- 
nals that  may  be  made 
with  this  machine,  we 
may  suppose  the  arm 
nearest  the  indicator, 
reckoning  in  the  order  of  the  numbers 
as  shown  in  the  figure,  to  indicate  tens, 
and  the  other  units ;  then  the  signal  re- 
presented in  the  figure  will  be  17,  which 
may  be  taken  to  denote  a  letter  of  the 
alphabet.  If  the  arm  on  the  left  had  the 
position  indicated  by  3,  and  that  on  the 
right  the  position  indicated  by  6,  the  sig- 
nal woula  be  36.  In  this  manner,  the 
number  of  separate  and  independent  sig- 
nals, with  their  signification,  will  be  as  in 
the  following  table  : — 


No.  of 

Signifi- 

No. of 

Signifi- 

No. of 

Signifi- 

Signal. 

cation. 

Signal. 

cation. 

Signal. 

cation. 

1 

A 

15 

L 

36 

V 

2 

B 

16 

M 

37 

w 

3 

C 

17 

N 

45 

X 

4 

D 

23 

O 

46 

Y 

5 

E 

24 

P 

47 

Z 

6 

F 

25 

Q 

56 

7 

G 

26 

R 

57 

12 

H 

27 

S 

67 

13 

I 

34 

T 

14 

K 

35 

U 

In  1803,  Ronalds  constructed  a  tele- 
graph by  galvanism,  which  worked 
through  coils  of  8  miles  of  wire,  and 
Wedgewood,  in  1817,  formed  and  worked 
a  voltaic  telegraph. 

TELEGRAPHS,  ELECTRIC.  It  is 
mainly  owing  to  the  labors  of  S.  F.  B. 
Morse,  in  the  United  States,  and  Cook  and 
Wheatston  in  England,  that  electrical 
telegraphs  owe  their  practical  application. 

In  Cook  and  Wheatston's  first  ap- 
paratus, five  needles  were  arranged,  with 
their  axis  in  a  horizontal  line,  the  nee- 
dles hanging  vertically  :  each  of  the 
electro-magnetic  coils  was  connected  with 
one  of  the  long  conducting  wires  at 
one  end,  and  was  united  at  the  other  with 


a  common  rod  of  metal,  which  joined  to- 
gether similar  ends  of  all  the  coils.  The 
current  was  transmitted  from  opposite 
ends  of  the  wires,  where  an  appropriate  set 
of  finger  keys  (5  pair)  for  making  connec- 
tion with  the  battery,  was  placed  through 
two  of  the  wires  at  once.  When  the  key 
was  pressed  down,  the  needles  assumed 
various  positions  with  respect  to  each 
other,  and  these  were  made  to  indicate 
signals  according  to  entries  in  the  signal 
book.  The  instruments  at  the  two  sta- 
tions are  always  reciprocating ;  that  is,  at 
the  ends  of  the  line  was  placed  an  instru- 
ment, a  set  of  finger  keys,  and  a  voltaic 
battery,  so  that  either  station  could  re- 
ceive or  transmit  a  signal.  By  a  beauti- 
ful arrangement,  a  bell  or  alarm  could  be 
rung,  when  the  attention  of  the  clerk 
at  the  distant  terminus  was  required. 
Mr.  Cook  obtained,  in  1838,  further  im 
provements  on  this  apparatus  without  al- 
tering its  chief  features. 

The  basis  of  this,  and  indeed  of  all  elec- 
tric telegraphs,  is  the  fact  discovered  by 
CErsted,  that  when  a  magnetic  needle  is 
subjected  to  a  current  of  electricity,  the 
needle  deviates  towards  a  right  angle  to 
the  position  in  which  it  stood  originally. 
This  was  the  simplest  form  of  telegraph 
of  Cook  and  Wheatston  : — A  magnetic 
needle  was  placed  behind  a  vertical  dial, 
its  axis  is  prolonged  out  in  front  of  the 
plate,  and  a  second  needle  suspended  to 
it,  so  that  the  latter  moves  similarly  when 
the  needle  behind  is  impelled ;  a'coil  ot 
wire  traverses  above  and  below  the  inner 
needle,  and  when  the  ends  of  this  coil  are 
brought  into  contact  with  the  poles  of  a 
battery,  and  the  needle  thus  brought 
within  the  circuit,  it  is  immediately  de- 
flected, and  carries  the  outer  needle  along 
with  it.  This  latter  is  the  indicator. 
Slops  are  placed  on  each  side  of  the 
needle  to  limit  its  motion  on  either  side, 
and  the  letters  are  read  off  by  a  scale  of 
arbitrary  movements.  Thus  if  the  point 
of  the  needle  move  once  to  the  right  to 
express  A,  twice  to  the  right  might  ex- 
press B;  once  to  the  left,  E,  and  so  on. 

Dr.  Stenheil  constructed  an  electric  tele- 
graph between  Munich  and  Bogenhausen, 
in  1837,  in  which  he  availed  "himself  of 
the  conducting  power  of  the  earth,  thus 
saving  the  cost  of  erection,  the  earth  oc- 
cupying the  place  of  the  return  wire. 

In  the  same  year  Mr.  Morse's  invention 
was  publicly  tested.  It  was  the  first  practi- 
cal registering  instrument,  the  various  sig- 
nals being  traced  on  a  strip  of  paper.  In 
June,  1844,  the  telegraph  was  constructed 
by  him  between  Baltimore  and  Wash- 


tel] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


635 


ington,  through  the  aid  afforded  him  by- 
Congress,  who  advanced  30,000  dollars. 
Mr.  Morse  has  taken  out  patents  for  im- 
provements in  his  apparatus,  the  latest 
of  whic/a  was  in  1848,  for  an  "  electro- 
magnet, recording  telegraph."  To  Mr. 
Morse  ifc  certainly  due  the  credit  of  be- 
inor  the  first  who  set  up  a  practical  mag- 
netic telegraph  invented  in  1832. 

Morse's  Telegraph.  This,  the  oldest 
telegraph  of  this  kind  in  the  United 
States,  may  be  described  as  worked  by  a 
main  circuit  and  distant  battery. 

The  principle  of  this  telegraph  is  based 
upon  the  temporary  induction  of  a  piece 
of  soft  iron  with  magnetism,  by  the  cur- 
rent of  galvanism  passing  around  it ;  this 
piece  of  soft  iron  is  called  an  electro  mag- 
net, and  it  operates  a  walking-beam  peu, 
to  make  mechanical  marks  upon  a  ribbon 
of  paper  carried  along  with  a  uniform 
motion,  against  the  face  of  a  grooved 
metal  roller. 

The  batteries  used  are  Grove's  zinc  and 
platinum,  and  two  liquids.  Any  number 
of  these  may  be  used ;  from  4  to  10  at 
termini  are  the  usual  number.  To  form 
the  electric  circuit,  one  end  of  a  copper 
wire  is  attached  to  the  end  platina  plate, 
and  the  other  end  of  the  copper  wire  to 
the  zinc  cylinder.  A  wire  is  not  required 
to  run  round  all  the  circuit — any  metallic 
connection,  such  as  brass  plates,  &c,  &c, 
may  form  part  of  it.  The  battery  with 
the  key  attached,  and  the  small  table,  we 
will  suppose  to  be  at  the  Philadelphia 
station,  and  the  telegraph  register  to  be  at 
New- York.  A  wire  runs  from  the  pla- 
tina plate  up  to  the  metallic  binding  screw 
connection  on  the  small  table  above,  and 
the  other  wire  runs  from  the  zinc,  and  is 
connected  with  the  first  wire  by  the  me- 
tallic connection  of  the  register  at  New- 
York.  This  forms  the  circuit.  The  key 
is  fixed  upon  a  pivot  axis,  to  be  gently 
pressed  by  the  operator's  fingers  on  the 
top  of  an  ivory  button.  The  circuit  is 
now  broken,  and  a  small  gap  in  the  key 
above  the  wire  from  the  battery  shows 
the  metallic  connection  to  be  open.  By 
pressing  upon  the  butt  end  of  the  key, 
its  metal  surface  comes  in  contact  with 
the  metal  termination  of  the  wire  from 
the  battery,  and  then  the  circuit  is  closed, 
and  the  electric  fluid  fleets  along  to  the 
distant  station,  as  in  the  present  instance, 
New- York. 

In  connection  with  the  register  there  is 
a  ribbon  of  paper  passing  from  the  roll 
between  two  small  metal  rollers  of  the  re- 
gister. This  strip  is  drawn  through  be- 
tween the  rollers  by  their  motion,  they 


revolving  towards  the  paper  roll,  drawing 
in  the  paper.  Motion  is  given  to  these 
rollers  by  a  train  of  clockwork  gear 
wheels,  which  are  moved  by  the  weight 
below  the  machine.  The  upper  small 
roll  has  a  small  groove  running  around 
its  periphery,  and  the  ribbon  of  paper  is 
drawn  through  against  its  under  surface. 
The  instrument  to  indent  the  paper  is  a 
pen-lever.  It  is  suspended  on  a  pivot 
axis  at  its  middle,  and  its  action  is  like  a 
walking-beam,  but  the  stroke  it  makes  is 
very  short — not  over  the  one-eighth  of 
an  inch  at  both  ends.  This  pen-lever  is 
very  nicely  poised,  and  at  its  extreme 
end  from  the  paper  its  stroke  is  nicely 
regulated  by  a  set  or  button  screw. 
There  is  a  metal  pen  attached  to  the  lever 
and  fixed  on  a  pivot  like  a  walking-beam. 
When  one  end  is  drawn  down,  the  other 
end  flies  up,  and  having  a  steel  point  on 
it  it  marks  a  strip  of  paper  running  along 
a  Toller,  which  is  drawn  along  between 
other  two  rollers.  Now,  by  letting  the 
other  end  of  this  pen  come  up,  the  steel 
point  drops,  and  then  it  is  thrown  up 
again,  leaving  a  space  between  the  two 
marks  on  the  paper.  Now,  as  the  paper 
is  always  moving,  and  as  the  point  is 
held  to  it  for  a  longer  or  shorter  time, 
marks  are  made  of  dots,  spaces  and 
dashes — thus  .  for  E,  and  —  for  L,  and 
.  —  .  for  F,  and  thus  by  a  combination  of 
dots,  spaces  and  dashes,  the  whole  al- 
phabet is  formed,  and  these  letters  made 
into  words,  and  the  words  into  sentences 
— compose  the  message.  An  electro- 
magnet is  used  on  Morse's  telegraph  to 
operate  the  walking-beam  pen.  It  is  fit- 
ted with  an  armature,  whose  attraction 
and  withdrawal  gives  motion  to  the  lever 
or  walking-beam  ;  the  breaking  and  clos- 
ing the  circuit  is  effected  by  a  key  of 
brass  insulated  by  ivory  at  Philadelphia, 
and  writes  the  messages  in  New-York. 

The  magnet  in  connection  with  the  re- 
gister, is  made  of  a  piece  of  soft  iron,  pure 
and  free  from  carbon,  sulphur,  &c.,'and 
is  wrapped  round  with  fine  copper  wire, 
covered  with  silk.  This  coil  of  wire  is 
called  a  helix.  It  is  attached  to  the  wire 
of  the  battery  by  a  metallic  connection  at 
one  end,  and  the  other  end  of  the  helix 
— for  it  must  be  made  of  continuous  wire 
— is  attached  to  the  wire  from  the  other 
end  of  the  battery,  thus  forming  part  of 
the  electric  circuit.  This  magnet  is  made 
almost  always  of  a  U  form,  but  this  is  not 
so  essential.  This  electro-magnet  has  no 
attractive  force  except  when  the  electric 
circuit  is  closed  and  the  fluid  rushing 
along  the  wire,  and  then  its  attraction  is 


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CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tel 


considerable.  The  end  of  the  pen  lever 
has  the  steel  pen  on  it,  so  that  when 
the  operator  at  Philadelphia  presses  his 
hand  upon  the  key,  the  circuit  is  closed, 
the  end  of  the  pen-lever  above  the  magnet 
is  drawn  down  to  the  magnet,  and  the 
pointer  at  the  other  end  is  thrown  against 
the  strip  of  paper.  Whenever  the  finger 
is  lifted  off  the  key,  the  circuit  is  open, 
the  magnet  loses  all  attractive  power,  and 
the  pointer  then  drops  and  does  not  touch 
the  paper.  It  will  thus  he  observed  that, 
by  tapping  on  the  key  at  Philadelphia 
the  circuit  is  broken  and  closed  to  New- 
York,  and  the  electro-magnet  actuates 
the  pen-lever  to  produce  the  characters 
we  have  described,  which  are  put  to- 
gether to  make  words,  and  the  words 
then  put  together  to  make  sentences. 

There  is  a  key  and  register  placed  on 
the  same  table  at  every  station  ;  and  this 
is  necessary  for  the  reception  and  trans- 
mission of  messages.  Each  station  has 
a  battery  and  each  register  has  a  register- 
ing magnet,  which  produces  the  marking 
and  is  in  the  local  circuit.  But  there  is 
another  magnet  called  the  receiving  mag- 
net placed  in  the  circuit  of  the  main  line; 
it  also  forms  a  part  of  the  apparatus  of 
the  register.  The  office  of  the  receiving 
magnet  is  to  close  and  break  the  circuit  of 
the  register  magnet.  It  is  on  the  exclusive 
use  of  this  instrument  and  the  combina- 
tion, that  the  value  of  the  Morse  patent  is 
based.  At  the  distance  of  30  miles  the 
electro  fluid  becomes  so  attenuated  in  pow- 
er that  it  would  not  be  capable  of  indenting 
the  paper.  To  render  the  attenuated  cur- 
rent available,  the  receiving  magnet  is  in- 
terposed, differing  from  common  electro- 
magnets in  the  length  and  fineness  of  the 
helix,  3000  feet  of  wire,  well  covered,  be- 
ing no  uncommon  length  ;  the  lever  at- 
tached to  the  armature  of  this  magnet  is 
so  delicate  as  to  affect  the  surface  if  coat- 
ed with  a  little  dust,  or  even  strongly 
breathed  on.  The  immediate  use  of  it  is 
to  break  and  close  the  circuit,  consisting 
of  the  register  magnet,  small  battery,  and 
sufficient  connecting  wire. 

Grove's  battery,  though  objectionable 
on  account  of  the  nitric  acid  vapors,  is 
still  the  most  economical.  The  zinc  cyl- 
inders of  the  battery  are  2  lb.  weight 
each,  and  cast  very  smooth.  ■  Sulphate  of 
soda  is  added  to  the  sulphuric  acid  in  the 
zinc  cell ;  this  prevents  local  action  and 
renders  reamalgamation  unnecessary. 

The  number  of  the  cellsgive  efficiency  to 
the  battery.  Eighteen  members  of  Smee's 
battery,  each  of  an  inch  square,  are  com- 
petent to  work  through  80  miles  ;  a  single 


cell,  no  larger  than  a  thimble,  will  work 
through  six  miles.  A  series  of  30  of 
Grove's  battery  is  the  average  number 
for  150  miles.  The  "  main  battery"  does 
not  require  to  be  charged  oftener  than 
once  in  5  weeks.  The  acids  of  the  "  local 
battery"  require  daily  replenishment. 
The  use  of  poles  for  the  support  of  wires 
is  universal  in  this  country.  In  Prussia, 
the  wires  are  buried  under  ground  and 
covered  with  gntta  percha.  In  England 
they  are  generally  encased  in  a  tube  and 
lie  upon  the  ground  or  but  little  buried : 
latterly  they  are  being  placed  on  poles 
similar  to  the  practice  of  France  and  this 
country.  The  height  of  the  poles  set  in 
these  states  vary,  being  on  an  average 
30  feet,  buried  5  feet  in  earth,  and  the 
diameter  at  the  top  being  not  less  than  6 
inches ;  on  these  are  placed  glass  caps  or 
rests  for  the  wire,  which  is  of  iron,  weigh- 
ing from  300  to  330  lbs.  per  mile.  It  is 
either  single  or  twisted,  naked  or  galvan- 
ized. The  naked  wire  is  generally  pre- 
ferred, and  costs  from  6  to  10  cents  a  lb. 
The  great  simplicity  of  this  American 
telegraph  is  the  use  of  the  ground  as  the 
return  conductor:  thus  rendering  only 
one  wire  needful.  It  also  proves  a  better 
conductor  than  wire,  the  current  seeming 
to  prefer  it.  Communication  is  easily 
established  with  it:  in  cities  a  gas  pipe 
answers  ;  anywhere  a  metal  plate,  buried 
in  the  ground,  or  immersed  in  a  river, 
effects  the  object.  A  hair  wire  suspend- 
ed from  the  travelling  wire  and  dipping 
in  a  river  is  sufficient  to  break  the  circuit 
as  effectually  as  if  the  wires  were  cut. 
No  matter  how  many  stations  intervene 
between  the  termini,  there  is  no  altera- 
tion produced  on  the  current  when  the 
wires  are  well  insulated.  On  one  of  the 
lines  there  are  16  stations,  each  of  which 
unite  with  each,  or  all  the  others,  each 
receiver  preserving  a  closed  circuit,  while 
the  transmitting  operator  manipulates 
with  his  key.  The  average  price  of  trans- 
mission is  25  cents  for  ten  words  100  miles ; 
this  is  much  below  the  Prussian  tariff.  In 
England  the  charge  is  so  high  as  to  leave 
its  benefit  only  in  the  hands  of  a  few. 
A  skilful  operator  knows  by  the  sound 
of  the  call  in  his  office  where  the  intelli- 
gence comes  from,  and  the  abbreviations 
are  so  numerous  that  a  ready  penman 
cannot  keep  up  with  the  delivery  of  a 
message :  as  many  as  25,000  letters  have 
been  transmitted  in  an  hour  and  a  half  by 
two  instruments  and  wire.  Changes  of 
weather  in  the  earth's  surface,  and  gene- 
ral disturbance  of  atmospheric  electrical 
equilibrium  renders  the  insulation  imper. 


tel] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


637 


feet  and  transmission  of  messages  are  put 
a  stop  to. 

The  country  between  Mobile  and  New- 
Orleans  is  an  instance  of  the  difficulty  of 
writing  through  a  damp  atmosphere,  for 
although  it  is  only  190  miles  by  telegraph 
line,  yet  it  is  with  difficulty  they  can 
write  "that  distance,  and  it  requires  the 
most  strict  attention  to  the  line  to  keep  it 
in  working  order,  while  on  the  same  line 
they  work  in  many  places  over  400  miles. 

House's  Telegraph  machinery  is  much 
more  complex  than  Morse's,  and  costs  in 
construction  ten  times  as  much.  Its 
object  is  to  make  at  one  end  of  a  wire  the 
revolution  of  a  disc,  upon  whose  edge 
the  Roman  letters  are  raised  synchronous 
with  the  operations  of  a  lettered  finger 
board  at  the  other  end  of  the  wire.  So 
that  at  the  touching  of  A  on  the  finger 
board,  the  wheel  presents  and  impresses 
A  on  a  slip  of  paper.  The  paper  is 
moved,  so  that  the  letters  succeed  each 
other,  as  in  ordinary  printing,  and  a  visi- 
ble impression  is  made  by  the  arrange- 
ment similar  to  the  manifold  writer.  The 
operator  at  New- York  plays  upon  his  ma- 
chine, like  a  lady  at  her  piano,  and  at  Bos- 
ton a  little  arm  is  seen  revolving  round 
and  round,  clicking  andprinting,  in  black 
letters,  E,  0,  Y,  A,  L,  E,  H,  O,  U,  S,  E, 
on  a  strip  of  paper.  On  Morse's  telegraph 
the  messages  have  to  be  re- written  by  a 
penman  into  plain  English. 

Bain's  telegraph. — Bain,  in  1843,  took 
out  the  patent  for  his  copying  telegraph. 

The  machine  consists  of  a  drum,  on 
which  is  rolled  a  card,  which,  with  a 
weight  attached,  moves  a  train  of  wheels. 
In  connection  with  the  drum,  by  pinion 
and  axle  and  bent  wheel,  hangs  a  rod,  on 
which  is  placed  a  revolving  pendulum 
supported  by  a  flexible  cord  with  a  screw 
attached,  which  can  raise  or  lower  the 
pendulum ;  to  another  wheel,  the  axle  of 
which  is  carried  through  the  print  plate 
of  the  instrument  two  lesser  wheels  are 
attached,  upon  which  there  are  metal  cy- 
linders movable  by  a  pulley  and  axle, 
which  winds  a  silk  cord  fastened  to  a 
steel  rod  to  the  extremity  of  which  is  a 
binding  screw  to  hold  a  fine  wire  or 
needle.  This  latter  can  be  brought  into 
contact  with  the  cylinders,  any  non-con- 
ducting substance  interposed  between 
the  cylinders  and  the  needle  interrupts 
the  current,  and  the  apparatus  thus  be- 
comes available  for  copying  work.  The 
motion  given  to  the  wheelwork  by  the 
weight  is  rendered  uniform  by  the  revolv- 
ing pendulum.  A  peculiarity  in  the  form 
of  the  escapement  gives  it  an  isochron- 


ous motion  by  means  of  a  vertical  pen- 
dulum, the  length  of  which  is  regulated 
by  screws,  so  as  to  check  any  deviation  in 
rate  of  motion  of  the  revolving  pendulum. 
Electro-magnets  are  thus  dispensed  with. 
This  apparatus  is  used  for  transmitting 
and  receiving;  for  transmission,  the 
message  may  be  written  on  tinfoil  or  paper, 
coated  with  Dutch  metal,  varnish,  or  any 
non-conductor,  or  by  moistening  the  back 
of  the  paper  and  then  writing  on  the 
metal  surface  with  a  blunt  style.  This 
communication  is  then  laid  on  one  of  the 
cylinders,  and  a  cylinder  of  the  corres- 
ponding instrument  at  the  receiving  sta- 
tion is  covered  with  chemically  prepared 
paper.  A  current  of  electricity  being 
generated  by  a  battery  at  the  transmitting 
station,  is  passed  through  the  instrument 
there  and  conveyed  by  a  single  wire  to 
the  corresponding  instruments  at  the  re- 
ceiving station,  whence  it  returns  back 
through  the  earth  to  the  battery.  As  the 
cylinders  rotate,  the  arm  descending  with 
the  needle  traces  a  continuous  spiral  line 
from  the  top  to  the  bottom  of  the  cylin- 
der which  becomes  a  permanent  mark  on 
the  chemically  prepared  paper,  broken  at 
intervals,  corresponding  to  the  marks 
made  with  the  non-conducting  material 
on  the  metallized  paper. 

The  writing  may  be  made  with  a  con- 
ducting material  on  a  non-conducting 
surface,  when  the  marks  composing  the 
received  communication  will  be  repre- 
sented by  dots  and  lines  upon  a  plain 
ground. 

The  chemical  paper  consists  of  fine  thin 
paper  soaked  with  a  solution  of  yellow 
prussiate  of  potash,  and  afterwards  dip- 
ped in  weak  nitric  acid.  This  tends  to 
facilitate  the  decomposition  of  the  prus- 
siate, the  acid  being  a  good  conductor ;  a 
blue  mark  is  left  where  the  needle  touches. 

Mr.  Bain's  telegraphs  have  been  exhib- 
ited before  the  French  government,  and 
will  form  the  medium  of  telegraphing  in 
that  republic.  On  that  occasion,  a  com- 
mittee of  the  French  Legislative  Assem- 
bly, at  the  head  of  which  was  the  cele- 
brated astronomer,  Le  Verrier,  was  ap- 
pointed to  investigate  the  merits  of  this 
invention.  They  caused  the  experiments 
to  be  repeated  in  their  presence.  A  mes- 
sage consisting  of  several  thousand  word3 
was  transmitted  to  Lille  and  back  along 
a  single  wire  (the  wire  being  united  at 
Lille  so  as  to  carry  back  the  message),  at 
the  rate  of  about  1,500  letters,  or  nearly 
400  telegraphic  words  per  minute.  The 
committee  reported  favorablv  of  the  pro- 
ject, and  the  government  ordered  a  set  of 


638 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[tel 


apparatus  to  be  constructed,  to  be  placed 
in  the  first  instance  on  the  line  between 
Paris  and  Calais.  This  line  was  com- 
pleted in  the  early  part  of  last  year  (1850), 
and  their  performance  was  witnessed  by 
the  correspondent  of  a  London  journal. 
His  own  dispatch  was  transmitted  and 
written  by  the  apparatus  in  his  presence 
at  the  rate  of  1,000  letters  per  minute, 
probably  as  quick  as  messages  will  be 
transmitted  by  it.  The  characters  were 
perfectly  distinct,  and  the  dispatch  was 
read  from  them  also  in  his  presence. 
This  speed  is  not  always  attained.  Bain's 
v  telegraph  is  not  worked  in  this  country 
any  quicker  than  Morse's.  In  both  cases 
the  rapidity  depends  on  the  skill  of  the 
operator. 

Bain's  telegraph  not  only  prints,  but 
makes  marks  of  a  chemical  nature,  in 
character  nearly  like  that  of  the  Morse 
telegraph,  but  no  "electro-magnet"  is 
used  except  to  rectify  operators.  By 
breaking  and  closing  the  circuit  at 
New-York,  the  pen  which  is  in  contact 
with  chemically  prepared  paper  at 
Philadelphia,  makes  blue  marks  on  the 
paper,  and  these  blue  marks  make  the 
message.  There  is  one  part  of  this  in- 
vention which  is  a  curiosity  in  its  way. 
The  operator  writes  the  message  first  on  a 
strip  of  paper,  by  perforating  it  with 
small  holes,  for  the  dashes  and  the  dots, 
and  by  making  this,  in  a  very  ingenious 
manner,  break  and  close  the  circuit,  a 
message  may  be  transmitted  to  any  place. 
When  there"  is  time  to  prepare  messages, 
this  is  a  ready  way  to  transmit  them"  ra- 
pidly. This  invention  embraces  the  idea 
of  printing  a  pattern  of  calico  in  Philadel- 
phia by  breaking  and  closing  the  circuit 
in  New- York. 

O"1  Reilly' s  Telegraph .  Th  3  s  i  s  n  ot  stri  ct- 
ly  a  distinct  teleerraph,  but  a  line  of  tele- 
graphic communication  established  by 
Mr.  O'Reilly,  in  which  he  avails  himself 
of  the  Morse  line  over  most  of  the  die- 
stances,  as  from  New-York  to  Louisville : 
thence  to  New-Orleans,  Bain's  telegraph 
is  used  now,  it  having  replaced  Messrs. 
Zook  and  Barns'  apparatus,  a  form  which 
has  not  been  patented,  but  which  had 
been  in  operation  on  that  line.  The 
O'Reilly  lines  extend,  besides  the  two 
distances  mentioned,  from  Pittsburg  to 
Cleveland  and  Detroit:  from  Dayton,  0., 
by  Lake  Erie  to  Chicago :  from  the  Ohio 
River  to  Evansville,  connecting  the  pre- 
vious line  at  Terre  Haute :  and  from  St. 
Louis  to  Dubuque,  Iowa,  supplying  the 
intermediate  cities.  The  Isew-Orleans 
route  divides  into  two  branches,  one  of 


which  proceeds  by  Tuscumbia,  Alabama, 
to  Memphis;  the  other  proceeds  from 
Jackson,  Miss.,  to  Vicksburg,  making  a 
total  distance  in  the  southern  route  of 
1,100  miles.  On  this  line  also,  the  naked 
iron  wire  i9  used,  it  being  found  to  act 
as  a  better  insulator  than  the  galvanized 
wire,  for,  in  the  latter  instance,  when  the 
wire  is  touched  by  leaves  of  trees,  which 
is  unavoidable  in  many  places,  the  cur- 
rent is  conveyed  off  the  polished  metal, 
but  if  the  wire  be  rusted,  it  becomes  in- 
sulated by  that  means,  and  the  current 
suffers  less  interruption. 

The  following  was  the  extent  of  tele- 
graph communication  in  this  country, 
Nov.  1847  :— 

Miles. 

New- York  to  Buffalo   509 

Troy  (o  Saratosa 36 

Auburn  to  Elmira 84 

Ithaca  to  Finghampton 46 

Syracuse  to  Oswego „ 3$ 

Buffalo  to  Chippewa,  C.  W 12 

Queensiown  to  Toronto 150 

Hamilton  to  London 75 

Toronto  to  Montreal 376 

Montreal  to  Quebec 180 

New- York  to  Washington,  D.C 224 

Washington  to  Petersburg 175 

'Philadelphia  to  Pittsburg 296 

Philadelphia  to  Poltsville 106 

'Lancaster  to  York    25 

Pittshnrg  to  Cincinnati 120 

Massillon  to  Cleveland 136 

Cincinnati  to  Louisville,  Ky 85 

New-York  to  Boston 237 

Boston  to  Lowell,  Mass 26 

*  Boston  to  Portland,  Maine 74 

Total 2969 

Contemplated  then,  since  perfected. 

Petersburg  to  New  Orleans 1427 

Buffallo  to  Detroit 350 

Detroit  to  Milwaukee 350 

Bridgeport  to  Montreal 300 

Norwich  to  Worcester 85 

Louisville  to  St.  Louis 300 

2812 

From  Macon  to  Flanepec 1000 

St.  Louis  to  New-Orleans 1000 


The  line  is  couble  nearly  the  whole 
way,  one  wire  connecting  each  interme- 
diate place,  and  one  connecting  the  ex- 
treme points.  These  lines  to  which  as- 
terisks are  appended  are  also  used  bv  the 
O'Reilly  line. 

The  foregoing:  are  on  the  Morse  princi- 
ple, which,  with  a  few  minorlines.  bring 
up  the  whole  extent  of  the  Morse  lines  to 
nearly  12,000  miles,  and  there  are  about 
2,000  on  House  and  Bain's  principles. 
The  telegraph  now  extends  from  Halifax 


tel] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


639 


to  New-Orleans,  and  as  far  west  as  Du-  | 
buque,  Iowa,  making  an  extent  of  22,000 
miles. 

A  contract  has  been  entered  into  by  the 
Mexican  Government  with  Wm.  George 
Stewart,  Esq.,  the  Mexican  consul  at 
New-York,  and  Senor  Juan  dela  Granja, 
of  Mexico,  to  build  a  line  from  Vera  Cruz 
to  the  city  of  Mexico — a  distance  of  three 
hundred  miles  —  on  the  understanding 
that  it  will  be  in  operation  by  the  first  of 
May,  1852,  as  far  as  El  Ojo  de  Agua,  a 
distance  of  one  hundred  and  twenty 
miles  from  the  latter  place.  Another 
line  will  soon  after  be  built  between  Aca- 
pulco  and  the  city  of  Mexico.  When 
both  are  completed  there  will  be  magnetic 
communication  between  the  Atlantic  and 
the  Pacific. 

Mr.  Wm.  Eobinson,  of  this  country,  is 
about  to  erect  and  manage,  in  Sweden 
and  Norway,  a  number  of  lines  of  mag- 
netic telegraph.  He  has  been  granted 
the  privilege  for  the  enterprise,  Avhich  is 
to  endure  ibr  fifty  years  ;  and  a  company, 
including  several  heavy  capitalists  in  this 
city  (N.  Y.)  and  Stockholm,  has  been 
formed  under  his  auspices. 

Messrs.  Westbrook  and  Eogers,  of  this 
country,  have  invented  a  telegraph  which 
records  signs  on  a  metallic  surface  con- 
nected with  the  earth  by  a  wire  conductor 
at  one  end,  and  to  a  galvanic  battery  and 
the  earth  at  the  other  end  of  the  circuit, 
by  the  use  of  acidulated  water  or  other 
fluid.  The  patentees  claim  "recording 
telegraphic  signs  on  the  surface  of  a  re- 
volving metallic  cylinder  plate,  or  other 
equivalent  surface,  by  means  of  an  acidu- 
lated or  saline  solution,  or  water  held  be- 
tween the  point  of  the  wire  conductor 
and  the  metallic  recording  surface,  by 
means  of  a  non-conducting  porous  sub- 
stance contained  in  a  glass  or  other  non- 
condensing  reservoir  in  which  the  record- 
ing fluid  is  contained,  to  which  the  elec- 
tric current  from  the  battery  is  applied  by 
menus  of  any  of  the  known'forms  of  man- 
ipulators and  anvils  used  for  making  and 
breaking  the  circuit.  The  recording  fluid 
being  employed  to  the  metallic  recording 
surface  substantially  in  the  manner  here- 
in fully  set  forth,  by  which  the  use  of 
every  description  of  paper  is  dispensed  l 
with,  thereby  saving  great  expense  in  ! 
telegraphing." 

Bakewell's   electric  copying  telegraph  ' 
is  very  similar  to  Bain's.     Messrs  Barlow 
and  Foster  have  made  improvements  in 
insulating  and  transmitting  the  currents.  ' 
The  limits  of  this  work  do  not  admit  of 
entering  upon  these  more  fully. 


On  the  27th  August,  1850,  an  experi- 
ment was  commenced  at  Dover,  England, 
for  establishing  a  telegraph  between  it  and 
Calais,  in  France.  The  steamer  Goliath 
took  the  wires  and  machinery  on  board. 
The  wire,  to  the  extent  of  30  miles,  and 
covered  with  gutta-percha,  was  wound  on 
a  drum  revolving  between  the  paddle- 
wheels.  Cape  Grinez,  on  the  French  coast, 
was  fixed  as  the  point  nearest  Dover,  be- 
ing 21  miles  distant.  The  wires  being 
made  fast  on  the  English  side,  and  the 
vessel  steaming  five  miles  per  hour,  the 
wire  as  it  unwound  passed  over  the  stern 
of  the  steamer  into  the  water,  and  was 
sunk  to  the  bottom  by  weights  of  25  lbs. 
each.  The  wires  were  carried  on  the 
French  side  up  the  declivity  of  the  cape 
124  feet.  It  was  carried  up  to  Shak- 
spear's  Cliff,  on  the  Dover  side.  On  the 
next  day,  the  batteries  being  affixed,  the 
line  worked  with  complete  success ;  the 
greatest  depth  of  water  was  180  feet. 
This  fact  has  shown  that  there  is  no  dif- 
ficulty in  telegraphing  through  the  ocean 
if  the  wires  be  not  deranged. 

It  has  been  proposed  to  extend  tele- 
graph wires  across  the  Atlantic,  between 
Halifax  or  Boston  and  the  west  coast  of 
Ireland.  It  is  difficult  to  understand, 
however,  how  these  could  be  sunk  to  the 
bottom  of  the  ocean,  which  is  between  2 
and  3  miles  deep  in  some  places,  and  if 
not  sunk  the  floating  wires  are  liable  to 
damage  from  icebergs  or  fish. 

TELESCOPE.  An  optical  instrument 
for  viewing  distant  objects.  This  sub- 
ject belongs  more  properly  to  the  depart- 
ment of  science,  but  as  it  is  an  instru- 
ment in  such  general  use  a  short  notice 
will  be  given  here.  It  is  not  the  mere 
distance  which  renders  an  object  invisible 
or  even  indistinctly  seen.'  There  are 
other  causes  which  come  into  play,  such 
as  the  diminution  of  the  angle  which  the 
object  subtends  which  diminishes  as  the 
distance  increases:  again,  the  light  which 
renders  the  object  visible,  becomes  less 
dense  as  the  distance  increases,  but  in  a 
much  faster  proportion,  and  all  the  rays 
of  light  which  have  an  object  do  not  reach 
the  observer,  some  being  lost  in  the  air  in 
their  passage.  For  an  object  to  be  seen 
in  ordinary  daylight  it  must  subtend  at 
the  eye  an  angle  of  30".  The  least  angle 
under  which  contiguous  objects  maybe 
clearly  distinguished  is  one  minute :  by 
the  aid  of  the  telescope  an  enlarged  image 
of  the  object  is  obtained,  and  within  cer- 
tain limits  the  object  is  not  only  appa- 
rently enlarsred  but  rendered  brighter  to 
the  eye.    The  telescope,  then,  enlargea 


640 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tel 


the  angle  under  which  objects  are  seen. 
Its  invention  has  been  ascribed  to  vari- 
ous persons.  Brewster  believes  that 
either  Roger  Bacon  or  Baptista  Porta 
formed  it  for  experiment.  It  has  also 
been  ascribed  to  Metius,  Lippersey,  and 
Jansen.  Lippersey  in  1608  actually  made 
one,  but  Jansen's  instrument  being  more 
notorious  roused  the  attention  of  Galileo, 
in  1609,  who  set  about  considering  the 
means  whereby  distant  objects  might  be 
rendered  visible.  He  was  soon  in  posses- 
sion of  a  telescope  which  magnified  three 
times  :  subsequently  he  increased  its 
power  very  much,  and  at  the  close  of  that 
year.he  discovered  the  satellites  of  Jupiter. 

There  are  two  kinds  of  telescopes,  re- 
fracting and  reflecting  telescopes.  The 
former  depending  on  the  use  of  appro- 
priately figured  lenses,  through  which 
the  rays  of  light  are  passed,  and  the  lat- 
ter on  the  use  of  specula  or  polished  me- 
tal mirrors  which  reflect  the  rays  ;  an 
inverted  image  of  the  object  being  form- 
ed in  both  cases  in  the  focus  of  the  lens 
or  mirror.  These  are  a  later  invention 
than  refracting  telescopes,  which  were  of 
a  simple  character  at  first,  made  up  chief- 
ly of  a  lens,  forming  the  object-glass,  and 
an  eye-glass  also  of  one  lens,  but  of  a 
much  snorter  focus.  The  different  re- 
frangibility  of  the  luminous  rays  pro- 
duced a  series  of  prismatic  colors,  which 
tinged  the  images  formed  by  the  tele- 
scope and  rendered  their  outline  thereby 
indistinct. 

Under  the  article  Lens  has  been  men- 
tioned the  various  forms  of  these  sur- 
faces, to  which  reference  may  be  had  for 
illustration  in  describing  this  instrument. 
By  combining  these  in  a  tube,  or  case,  the 
parallel  rays  from  the  object  are  brought 
to  one  point  without  loss  or  interference. 
The  naked  eye  can  see  objects  distinctly 
when  placed  at  a  great  distance,  that  is, 
when  the  rays  proceeding  from  the  ob- 
ject are  parallel  or  nearly  so;  consequent- 
ly if  an  object  be  placed  very  near  the 
eye,  and  it  the  rays  which  flow  from  it 
can  be  made  to  enter  the  eye  nearly  pa- 
rallel to  each  other,  we  must  see  it  dis- 
tinctly. This  parallelism  may  be  effected 
by  placing  close  to  the  eye  a  convex  lens 
and  holding  the  object  in  its  focus.  If  the 
latter  be  called  F,  and  the  centre  of  the 
lens  C,  by  placing  the  object  a  little  near- 
er than  F  the  rays  which  flow  from  it 
may  receive  the  exact  degree  of  divergen- 
cy which  they  have  when  the  object  is 
placed  six  inches  from  the  eye,  the  near- 
est distance  at  which  we  can  see  minute 
objects  distinctly.    If  the  distance  C  F 


be  one  inch,  the  object  at  F  will  have  its 
apparent  magnitude  six  times  greater  than 
when  it  is  seen  at  the  distance  of  six 
inches  without  the  lens.  It  is  therefore 
said  to  be  magnified  six  times  by  the 
lens.  This  constitutes  the  single  micro- 
scope, and  the  magnifying  power  of 
such  may  be  always  found  by  dividing 
six  inches  by  the  focal  distance  of  the 
lens.  Thus,  a  lens  the  l-10th  of  an  inch 
in  focal  length  will  magnify  60  times,  and 
one  the  l-1000th  of  an  inch  600  times. 

To  the  instrument  with  one  lens  which 
thus  magnifies  where  the  naked  eye  is  six 
inches  behind  it,  additional  magnifying 
power  may  be  given  by  bringing  the  eye 
within  an  inch  of  the  image,  that  is,  by 
viewing  the  image  with  an  additional  lens 
when  the  focal  distance  is  an  inch.  This 
lens  will  magnify  the  image  six  times, 
and  if  that  image  had  been  magnified  bv 
the  former  lens  ten  times,  then  the  mag- 
nifying effect  of  the  two  lenses  will  be 
10  X  6  =  60  times.  Such  is  the  astrono- 
mical telescope  by  which  objects  are  seen 
inverted,  and  the  magnifying  power  of 
which  is  always  equal  "to  the  focal  length 
of  the  oliject- glass,  or  the  lens  next  the 
object,  divided  by  the  focal  length  of  the 
eye-glass  or  the  lens  next  the  eye. 

The  principle  of  the  telescope  is  then 
simply  this  :  the  object-glass  forms  in  its 
focus  a  distinct  image  or  picture  of  the 
object  which,  thougn  very  much  smaller 
than  the  object,  is  yet  seen  under  a  much 
greater  angle,  or  magnified,  arid  this  im- 
age so  magnified  is  seen  under  a  still 
greater  angle,  or  still  farther  magnified,  by 
the  eye-glass,  which  enables  the  eye  to 
see  it  distinctly  at  a  distance  less  than  six 
inches.  The  terrestrial  telescope  differs 
from  the  astronomical  in  having  two  ad- 
ditional lenses  placed  in  the  tube  of  the 
eye-glass,  for  the  purpose  of  restoring  the 
inverted  image  to  its  erect  position  and 
thereby  accommodating  the  telescope  to 
terrestrial  objects ;  the  focal  lengths  of 
these  additional  lenses  being  usually  the 
same  as  that  of  the  eye-glass.  The  per- 
formance of  these  refracting  telescopes 
depends  most  essentially  on  the  goodness 
of  the  object-glass,  for  if  the  first  image 
be  bright  and  distinct  and  perfectly  ach- 
romatic, or  without  the  prismatic  colors 
at  its  edge,  there  is  little  difficulty  in 
forming  eye-pieces  to  magnify  it  without 
causing  it  to  undergo  any  sensible  alter- 
ation. When  suitable  lenses  are  obtain- 
ed, it  is  only  necessary  to  adjust  them  at 
proper  distances  in  the  tube  to  complete 
the  modern  telescope :  the  tube  keeping 
off  the  external  rays  which  would  other- 


tel] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


641 


wise  cross  and  interfere  with  the  parallel 
rays  coming  from  the  object.  In  reflect- 
ing telescopes  a  speculum  or  mirror  per- 
forms the  same  office  which  the  object- 
glass  does  in  those  of  the  refracting  kind : 
it  is  therefore  called  the  object-mirror. 
This  telescope  is  constructed  in  various 
forms,  differing  from  each  other  chiefly 
in  reference  to  the  contrivances  "which 
have  been  adopted  for  bringing  the  focal 
image  into  a  convenient  situation  for  be- 
ing viewed  by  the  eye-piece.  The  chief 
forms  are  the  Newtonian,  Gregorian, 
Cassegranian  and  Herschelian.  In  the 
Newtonian  telescope  the  mirror  was  at 
the  bottom  of  the  tube  and  the  image  re- 
ceived on  a  small  diagonal  plane  specu- 
lum, which  threw  the  rays  to  the  side  of 
the  tube  and  formed  the  image  there, 
when  it  could  be  viewed  by  the  eye-piece. 
In  the  Gregorian  telescope  the  incon- 
venience of  taking  a  lateral  view  is  avoid- 
ed. It  consists  in  a  concave  speculum 
A,  B,  fixed  in  a  tube,  but  pierced  in  the 
centre  with  a  hole,  through  which,  by 
means  of  a  lens  or  a  combination  of  len- 
ses, the  image  of  the  object  is  viewed. 
The  rays  forming  the  image  of  the  object, 
are  incident  on  a  small  concave  mirror  C, 
previous  to  which  the  rays  have  crossed 
themselves  at  the  focus  e,  the  image 
therefore  at  C  is  an  inverted  one:  this 
image  is  viewed  through  the  aperture  in 


the  mirror  where  the  plano-convex  lens 
receives  the  parallel  rays,  brings  them  to 
a  focus  at  x,  at  the  farther  side  of  which 
is  placed  the  eye-glass  or  lens  which  re- 
ceives the  rays  diverging  from  x,  restores 
them  to  their  parellelism  and  brings  the 
image  back  again  to  an  upright  condition. 
The  observer,  in  using  this  telescope,  is 
plaeed  in  a  line  with  the  object ;  whilst 
in  Newton's  he  is  at  right  angles  to  it. 
The  curvature  of  the  smaller  mirror  is 
usually  spherical,  though  it  should  pro- 
perly be  elliptical.  The  larger  mirror  is 
generally  hyperbolic.  In  the  Casscgrani- 
an  telescope  a  convex  mirror  is  substi- 
tuted for  the  concave  one. 

Mr.  Na-miylh  h:s  produced  an  im- 
provement in  the  reflecting  telescope, 
which  consists  in  having  the  centrings 


or  trunions  at  the  centre  of  gr&vity, 
through  one  of  which  in  a  tubular  form 
the  rays  from  the  reflector  within  are 
thrown  into  the  eyes  thus  placed,  as  in 
the  Newtonian  telescope,  at  the  side: 
and  the  advantage  of  this  arrangement  is 
that  the  eye  does  not  require  to  move  on 
a  movement  of  the  telescope.  In  order 
that  the  telescope  may  be  accommodated 
to  objects  at  different  distances,  it  is  ne- 
cessary that  the  tube  should  be  made  to 
slide  backward  and  forward,  and  the  ob- 
ject will  always  be  inverted  from  the  in- 
tersection of  the  rays  by  refraction,  and  its 
use  will  be  thus  limited.  An  erect  im- 
age may  always  be  obtained  by  adding 
two  other  convex  lenses  behind  C,  in  the 
illustration,  and  of  the  same  focal  length : 
but  a  loss  of  light  is  necessarily  produced 
by  their  use.  Spherical  aberration  may 
be  prevented  in  telescopes  in  the  same 
way  in  which  it  is  prevented  in  micro- 
scopes, namely,  by  giving  to  the  reflect- 
ing surface  such  a  configuration  as  will 
enable  it  to  reflect  all  the  rays  incident 
upon  it  to  one  focus.  The  parabola  and 
ellipse  possess  this  property,  and  nothing 
but  the  mechanical  difficulty  of  construct- 
ing mirrors  of  these  figures  prevents  their 
being  employed  instead  of  spherical  mir- 
rors. If  a  concave  eye-glass  be  substi- 
tuted for  the  lens  C  in  the  simple  refract- 
ing telescope,  we  have  the  Galilean  teles- 
cope, which  exhibits  objects  in  an  erect 
position  and  with  very  great  clearness. 

TELL-TALE.  The  dial  plate  at  the 
wheel,  showing  the  position  of  the  tiller. 

TELLURIUM.  This  rare  metal  has 
only  been  found  in  small  quantities  in 
the  gold  mines  of  Transylvania:  it  occurs 
in  the  metallic  state,  combined  with  gold 
or  silver.  It  is  white,  brilliant,  brittle, 
and  easily  fusible.  Its  specific  gravity  is 
about  6-25.  It  is  combustible,  and  often 
exhales  a  peculiar  odor,  like  horse-radish, 
which  Berzelius  ascribes  to  the  presence 
of  minute  portions  of  selenium.  It  forms 
a  protoxide  and  a  peroxide,  often  called 
tellurous  and  telluric  acids.  Its  equivalent 
is  either  32  or  64.  Tellurium  forms  a 
gaseous  compound  with  hydrogen,  which 
has  been  called  Jiydrotelluric,  acid. 

TENACITY  OF  THE  METALS.  The 
power  which  metallic  wires  possess  of 
sustaining,  without  breaking,  the  action 
of  a  suspended  weight.  See  Cohesion, 
Strength  of  Materials. 

TENON.  In  architecture,  the  end  of 
a  piece  of  wood  or  timber,  diminished 
usually  by  one  third  of  its  thickness, 
which  is  received  into  a  hole  correspond- 
ing to  it  in  size,  called  a  mortise,  by  which 


642 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


b 


expedient  the  two  are  held  jointed  or 
fastened  together. 

TEEKA  JAPONICA.  The  old  phar- 
maceutical designation  of  the  substance 
now  called  catechu.  It  was  formerly  re- 
garded as  an  earthy  mineral. 

TEEEA  SIENNA.  A  brown  ocher- 
ous  clay  brought  from  Sienna,  and  some- 
times used  as  a  pigment. 

TEREACE.  In  architecture,  a  raised 
natural  or  artificial  bank  for  the  purpose 
of  affording  a  promenade. 

TEEEA  COTTA,  literally  baked  clay, 
is  the  name  given  to  statues,  architectural 
decorations,  figures,  vases,  &c,  modelled 
or  cast  in  a  paste  made  of  pipe  or  potter's 
clay  and  a  fine  grained  colorless  sand  (fine 
quartz),  with  pulverized  potsherds,  slow- 
ly dried  in  the  air,  and  afterwards  fired 
to  a  stonv  hardness  in  a  proper  kiln. 

TEElt'E-VERTE.  Green  earth.  A 
species  of  chlorite  of  a  green  or  olive  color, 
found  in  Germany,  France,  Italy,  and 
this  Continent.  According  to  Klaproth, 
it  is  a  hydrated  silicate  of  oxide  of  iron 
and  potash,  with  a  little  magnesia  and 
alumina.  The  green  earth  of  Verona, 
once  used  as  a  pigment,  is  a  sub-species 
of  this  mineral. 

TESSELATED  PAVEMENT.  In  an- 
cient architecture,  a  pavement  formed  of 
small  square  pieces  of  stone  called  tesserce 
or  dies.  They  are  frequently,  indeed 
mostly,  found  inlaid  in  different  colors 
and  patterns,  and  with  a  central  subject. 
They  are  imbedded  in  cement,  and  rest 
on  prepared  hard  strata. 

TEST.  In  chemistry,  any  thing  by 
which  we  distinguish  the  chemical  nature 
of  substances  from  each  other;  thus,  in- 
fusion of  galls  is  a  test  of  the  presence  of 
iron,  which  it  renders  evident  by  the 
production  of  a  black  color  in  water  and 
other  liquids  containing  that  metal ;  in 
the  same  way  sulphuretted  hydrogen  is  a 
test  of  the  presence  of  lead,  and  nitrate  of 
baryta  of  sulphuric  acid.  In  metallurgy 
and  assaying,  the  porous  crucible  which 
absorbs  the  liquid  verifiable  oxide  of  lead 
and  other  metals  combined  with  it  is 
sometimes  called  the  test. 

TEXTILE  FABRICS.  Under  the  ar- 
ticles of  Flax,  Cotton,  and  Linen,  the 
manufacture  of  those  fabrics  is  describ- 
ed. Under  the  present  title,  only  a  few 
additional  observations  are  required  :  the 
reader  finding  further  information  under 
the  head  AVeaving. 

The  first  business  of  the  weaver  is  to 
adapt  those  parts  of  his  loom  which  move 
the  warp,  to  the  formation  of  the  various 
kinds  of  ornamental  figures  which  the 


cloth  is  intended  to  exhibit.  This  subject 
is  called  the  draught,  drawing  or  reading 
in,  and  the  cording  of  looms.  In  every 
species  of  weaving,  whether  direct  or 
cross,  the  whole  difference  of  pattern  or 
effect  is  produced,  either  by  the  succes- 
sion in  which  the  threads  of  warp  are  in- 
troduced into  the  heddles,  or  by  the  suc- 
cession in  which  those  heddles  are  moved 
in  the  working.  The  heddles  being 
stretched  between  two  shafts  of  wood,  all 
the  heddles  connected  by  the  same  shafts 
are  called  a  leaf;  and  as  the  operation  of 
introducing  the  warp  into  any  number  of 
leaves  is  called  drawing  a  warp,  the  plan 
of  succession  is  called  the  draught. 
When  this  operation  has  been  performed 
correctly,  the  next  part  of  the  weaver's 
business  is  to  connect  the  different 
leaves  with  the  levers  or  treadles  by 
which  they  are  to  be  moved,  so  that  one 
or  more  may  be  raised  or  sunk  by  every 
treddle  successively,  as  may  be  required 
to  produce  the  peculiar  pattern.  These 
connections  being  made  by  coupling  the 
different  parts  of  the  apparatus  by  cords, 
this  operation  is  called  the  cording.  In 
order  to  direct  the  operator  in  this  part 
of  his  business,  especially  if  previously 
unacquainted  with  the  particular  pattern 
upon  which  he  is  employed,  plans  aro 
drawn  upon  paper.  These  plans  are  hor- 
izontal sections  of  a  loom,  the  heddles  be- 
ing represented  by  lines  across  the  paper, 
and  the  treddles  under  them,  and  crossing 
them  at  right  angles.  In  actual  weaving, 
the  treddles  are  placed  at  right  angles 
to  the  heddles,  the  sinking  cords  descend- 
ing perpendicularly  as  nearly  as  possible 
to  the  centre  of  the  latter.  Placing  them 
at  the  left  hand,  therefore,  is  only  for 
ready  inspection  and  for  practical  conve- 
nience. The  right  hand  thread  passes 
through  the  eye  of  a  heddle  upon  the 
back  feaf  and  is  disconnected  with  all  the 
other  leaves ;  the  next  thread  passes 
through  a  heddle  on  the  second  leaf;  the 
third,  through  the  third  leaf;  the  fourth, 
through  the  fourth  leaf;  and  the  fifth, 
through  the  fifth  or  front  leaf.  One  set 
of  the  draught  being  now  completed, 
the  weaver  recommences  with  the  back 
leaf,  and  proceeds  in  the  same  succes- 
sion again  to  the  front.  Two  sets  of 
the  draught,  similar  to  the  one  which 
had  been  furnished,  it  is  understood  by 
weavers  (who  seldom  draw  more  than 
one  set),  must  be  repeated  until  the  warp 
is  concluded.  When  they  proceed  to 
apply  the  cords,  the  right  hand  part  of 
the  plan  serves  as  a  guide.  In  all  the 
plans  furnished  to  the  weavers,  excepting 


the] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


643 


one,  which  shall  he  noticed,  a  connection 
must   be   formed,  by  cording,   between 
every  leaf  of  heddles  and  every  treddle  ; 
for  all  the  leaves  must  either  rise  or  sink. 
The  raising  motion  is  effected  by  coup- 
ling the  leaf  to  one  end  of  its  correspond- 
ent top  lever;  the  other  end  of  this  lever 
is  tied  to  the  long  march  below,  and  this 
to  the  treddle.     The  sinking  connection 
is  carried  directly  from  under  the  leaf  to 
the  treddle.    To  direct  a  weaver  which  of 
these  connections  is  to  be  formed  with 
each  treddle,  a  black  spot  is  placed  when 
a  leaf  is  to  be  raised,  where  the  leaf  and 
treddle  intersect  each  other  upon  the 
plan,  and  the  sinking  connections  are 
left  blank.    Those  who  have  been  accus- 
tomed to  manufacture  and  weave  orna- 
mented cloths,  never  consume  time  by 
representing  either  heddles  or  treddles  as 
solid  or  distinct   bodies.     They  content 
themselves  with  ruling  a  number  of  lines 
across  a  piece  of  paper,  sufficient  to  make 
the  intervals  between  these  lines  repre- 
sent   the    number   of   leaves    required. 
Upon  these  intervals  they  merely  mark 
the   succession  of  the  draught,  without 
producing  every  line  to  resemble  a  thread 
of  warp.     At  the  left  hand  they  draw  as 
many  lines  across  the  former  as  will  afford 
an  interval  for  each  treddle ;  and  in  the 
squares  produced  by  the  intersections  of 
these  lines,  they  place  the  dots,  spots,  or 
ciphers  which  denote  the  raising  cords. 
It  is  also  common  to  continue  the  cross 
lines  which  denote  the  treddle  a  consid- 
erable length  beyond  the   intersections, 
and  to  mark  by  dots,  placed  diagonally  in 
the  intervals,  the  order  or  succession  in 
which  the   treddles   are  to   be   pressed 
down  in  weaving. 

THEODOLITE.  A  most  important 
surveying  instrument  for  measuring  hor- 
izontal angles,  or  the  angular  distances 
between  objects  projected  on  the  plane  of 
the  horizon.  This  instrument  is  various- 
ly constructed,  and  provided  with  sub- 
ordinate apparatus,  according  to  the 
price,  or  the  particular  purposes  to  which 
it  is  to  be  applied.  One  of  the  most  gen- 
erally useful,  consists  of  two  concentric 
horizontal  circular  plates  A  and  B,  which 
turn  freely  on  each  other.  The  lower  or 
graduated  plate  B,  contains  the  divisions 
of  the  circle,  and  the  upper  or  vernier 
plate  has  two  vernier  divisions  «,  dia- 
metrically opposite,  only  one  of  which  is 
sho^n  in  the  cut.  The  vertical  axis  C 
consists  of  two  conical  parts,  the  one 
working  within  the  other.  The  external 
part  is  attached  to  the  graduated  plate  B, 
and  the  internal  to  the  vernier  plate  A. 


The  plane  of  the  circle  is  adjusted  to  the 
horizon    by  the  screws    b   b   b,  acting 


against  a  plate  of  metal  resting  on  the 
staff-head  supporting  the  instrument. 
The  vernier  plate  carries  two  spirit  levels, 
c  c  at  right  angles  to  each  other,  with 
their  proper  adjusting  screws,  by  which 
the  circle  is  brought  accurately  into  the 
horizontal  plane  indicated  by  the  levels. 
The  horizontal  axis  of  the  vertical  limb  of 
the  instrument  is  supported  by  a  frame 
attached  to  the  vernier  plate,  and  turn- 
ing along  with  it  about  the  vertical  axis. 
To  the  horizontal  axis  D,  a  telescope, 
with  cross  wires  in  its  focus,  is  attached, 
which  moves  in  the  vertical  plane,  by 
the  graduated  circle  E,  and  is  used  for 
observing  the  objects  whose  angular  dis- 
tance is  to  be  measured,  and  also  for  tak- 
ing altitudes,  or  measuring  vertical  an- 
gles; a  spirit  level  is  fixed  beneath  the 
telescope  for  its  adjustment.  F  is  a  mi- 
croscope for  reading  off  the  vernier  divi- 
sions. The  screws  g,  h,  are  for  regulating 
and  fixing1  the  external  part  of  the  vertical 
axis  C.  To  measure  the  angular  distance 
between  any  two  objects,  the  telescope 
is  turned  round  along  with  the  vernier 
circle  (the  graduated  circle  remaining 
fixed),  until  it  is  brought  to  bear  exactly 
upon  one  of  the  objects ;  it  is  then  turned 


644 


CYCLOPEDIA   OP   THE   USEFUL   ARTS. 


r ._ 

[THE 


round  tintil  it  is  brought  to  bear  on  the 
other  object,  and  the  arc  which  the  ver- 
nier has  described  on  the  graduated  cir- 
cle, measures  the  angle  required.  The 
observation  may  be  repeated  any  number 
of  times  in  order  to  insure  accuracy,  by 
means  of  a  repeating  stand,  which  turns 
round  concentrically  with  the  vertical  axis 
of  the  theodolite.  The  theodolite  is  riot 
only  a  most  essential  instrument  in  tri- 
gonometrical surveying  for  determining 
stations,  and  running  base-lines,  but  also 
in  geodetical  operations,  for  assisting  in 
determining  the  length  of  an  arc  of  the 
meridian.  For  this  latter  purpose  it  re- 
quires to  be  constructed  on  a  large  scale. 
THERMOMETER.  An  instrument  for 
measuring  variations  of  heat  or  tempera- 
ture. 

The  principle  upon  which  thermome- 
ters are  constructed,  is  the  change  of  vol- 
ume which  takes  place  in  bodies  when 
their  temperature  undergoes  an  altera- 
tion. Generally  speaking,  all  bodies  ex- 
pand when  heated,  and  contract  when 
cooled,  and  in  such  a  manner  that,  under 
the  same  circumstances  of  temperature, 
they  return  to  the  same  dimensions  ;  so 
that  the  change  of  volume  becomes  the 
exponent  of  the  temperature  which  pro- 
duces it.  But  as  it  is  necessary  not  mere- 
ly that  expansion  and  contraction  take 
place,  but  that  they  be  capable  of  being 
conveniently  observed  and  measured, 
only  a  small  number  of  bodies  are  adapted 
for  thermometrical  purposes.  Solid 
bodies,  for  example,  undergo  so  small 
a  change  of  volume  with  moderate  varia- 
tions of  temperature,  that  they  are  in 
general  only  used  for  measuring  very 
igh  temperatures,  as  the  heat  of  fur- 
naces, of  melting  metals,  &c.  Instru- 
ments for  such  purposes  are  called  py- 
rometers. (See  PtroMeter.)  The  gaseous 
fluids,  on  the  other  hand,  are  extremely 
susceptible  of  the  impressions  of  heat  and 
cold;  and  as  their  changes  of  volume  are 
great  even  with  moderate  accessions  of 
heat,  they  are  only  adapted  for  indicating 
very  minute  variations,  or  for  forming 
differential  thermometers.  (See  Differ- 
ential Thermometer.)  Liquids  hold  an 
intermediate  place ;  and  by  reason  of 
their  moderate  but  sensible  expansion 
through  the  ranges  of  temperature,  within 
which  observations  have  to  be  made  for 
by  far  the  greater  number  of  purposes, 
are  commonly  used  for  the  construction 
of  thermometers.  Various  liquids  have 
Keen  proposed,  as  oils,  ether,  spirits  of 
wine,  and  mercury ;  but  scarcely  any 
other  than  the  two  last  are  now  ever 


used,  and  mercury  by  far  the  most  gen- 
erally. 

The  ordinary  mercurial  thermometer 
consists  of  a  glass  tube,  with  a  bulb 
blown  at  the  lower  end.  Some  mercury 
is  boiled  in  the  tube,  and  the  whole  of 
the  atmospheric  air  driven  away  by  im- 
mersing the  open  end  of  the  tube  in  a 
cup  of  quicksilver ;  it  rises  in  the  glass 
as  the  latter  cools.  It  is  again  heated, 
and  closed  at  the  open  end.  It  is  then 
immersed  in  melting  ice  and  in  boiling 
water.  The  heights  at  which  the  quick- 
silver stands  in  these  cases  respectively, 
are  marked  32°  and  212°.  The  intervening 
space  is  divided  into  180°,  to  make  a 
Fahrenheit  thermometer,  and  100°  to 
make  a  centigrade  thermometer.  Alco- 
hol thermometers  are  used  to  indicate 
degrees  of  cold,  as  that  liquid  cannot  be 
broken. 

The  differential  thermometer  consists  of 
two  legs  connected,  with  a  fluid  working 
between  them  as  either  is  made  hotter 
than  the  other.  It  has  a  scale,  but  is  not 
very  accurate. 

Thermometers  are  often  slow  in  exhib- 
iting the  heat  of  new  situations,  and  time 
should  always  be  allowed,  according  to 
circumstances,  for  the  progression  of  the 
atomic  motion  into  or  out  of  the  mercury 
in  the  bulb. 

The  degrees  of  Celsius,  or  the  cen- 
tigrade scale,  when  desired,  may  be 
found  by  adding  or  subtracting  for 
every  degree  1*8  degree  to  or  from  the 
degree  of  Fahrenheit,  and  those  of  Reau- 
mur, by  adding  or  subtracting  2-25  de- 
grees to  or  from  Fahrenheit. 

THERMOSTAT,  is  the  name  of  an  ap- 
paratus for  regulating  temperature,  in 
vaporization,  distillation,  heating  baths 
or  hot-houses,  and  ventilating  apart- 
ments, &c. ;  for  which  Dr.  Ure  obtained 
a  patent  in  the  year  1831.  It  operates 
upon  the  physical  principle,  that  when 
two  thin  metallic  bars  of  different  expan- 
sibilities are  riveted  or  soldered  facewise 
together,  any  change  of  temperature  in 
them  will  cause  a  sensible  movement  of 
flexure  in  the  compound  bar,  to  one  side 
or  other ;  which  movement  may  be  made 
to  operate,  by  the  intervention  of  levers, 
&c,  in  any  desired  degree,  upon  valves, 
stop-cocks,  stove-registers,  air-ventila- 
tors, &c. ;  so  as  to  regulate  the  tempera- 
ture of  the  media  in  which  the  said  com- 
pound bars  are  placed.  Two  long  rulers, 
one  of  steel  and  one  of  hard  hammered 
brass,  riveted  together,  answer  very  well ; 
the  object  being  not  simply  to  indicate, 
but  to  control  or  modify  temperature. 


tin] 


CYCLOPEDIA    OF    TIIE    USEFUL    ARTS. 


645 


THRASHING  MACHINE.  The  em- 
ployment of  thrashing  machines  relieves 
the  laborers  from  the  severest  drudgery 
incident  to  agriculture ;  they  enable  the 
work  to  be  done  at  the  time  there  is  a  de- 
mand for  corn ;  and,  by  doing  it  better,  or 
separating  the  grain  (particularly  of  wheat) 
more  completely  from  the  straw,  they  add 
both  to  the  wealth  of  the  farmer  and  the 
produce  of  the  country.  To  the  farmer  of 
this  continent  they  are  invaluable,  as  sav- 
ing the  price  of  manual  labor.  This  latter  is, 
indeed,  a  most  important  consideration.  It 
is  calculated,  by  the  best  informed  agricul- 
turists, that  5  per  cent.,  or  one-twentieth 
part,  more  produce  is  afforded  by  a  crop 
thrashed  by  machinery  than  by  the  old 
method.  The  modern  thrashing  machine 
was  invented  in  Scotland,  about  the  year 
1758,  by  a  farmer  in  the  parish  of  Dum- 
blaine,  Perthshire,  and  afterwards 
brought  to  nearly  its  present  state  of  per- 
fection by  Mr.  Meikle,  a  millwright  of 
Haddingtonshire,  about  the  year  1786. 
Meikle's  thrashing  machine  consists  of  a 
cylinder  furnished  with  beaters  fixed  on 
its  circumference,  to  which  the  corn  be- 
ing presented  by  rollers,  the  ears  are 
beat  in  pieces  ;  and  while  the  grain  drops 
through  a  grating  into  a  winnowing 
machine,  the  straw  is  carried  forward, 
and  delivered  by  itself  ready  to  be  made 
up  into  bundles.  Some  thrashing  ma- 
chines only  beat  out  the  corn,  and  sepa- 
rate it  from  the  straw ;  while  others  beat 
it  out,  winnow  it,  and  sift  it. 

These  machines  may  be  driven  by 
horse,  cattle,  wind,  water,  or  steam. 
The  latter  is  almost  the  only  power  now 
used. 

THIEVES'  VINEGAR,  is  a  solution 
of  camphor  and  essential  oils  in  vinegar, 
and  is  used  as  a  preventive  to  contagion. 
TILT-HAMMER.  A  heavy  hammer 
used  in  iron-works,  which  is  worked  by 
machinery,  impelled  either  by  a  water- 
wheel  or  a  steam-engine.  Such  hammers 
are  extensively  used  in  the  manufacture 
of  iron  and  steel.  The  hammer  used  for 
hammering  the  blooms  of  iron,  is  usually 
called  a  lift  or  helve  hammer,  and  is  some- 
times of  the  enormous  weight  of  six  tons. 
The  tilt-hammer,  properly  so  called,  is  of 
lighter  dimensions,  and  is  worked  with 
greater  rapidity ;  a  specimen  of  the  kind 
usually  employed  in  the  manufacture  of 
steel,  and  in  the  forging  of  anchors, 
axles,  &c,  is  represented  in  the  accom- 
panying engraving,  a,  is  the  shank  or 
helve,  usually  formed  of  timber,  and 
sometimes  of  wrought  iron  ;  it  is  hung 
upon  an  axis  at  about  one-third  of  its 


length,  and  is  worked  by  a  series  of  re- 
volving cams  or  tappets  c  c,  fixed  into 
the  circumference  of  the  cam-ring  ft, 
mounted  upon  the  shaft  of  a  steam-engine 
or  water-wheel.  These  cams  act  succes- 
sively by  depressing  the  shorter  limb  of 
the  shank  a,  until,  by  the  continued  re- 
volution, it  is  disengaged,  and  the  oppo 


site  extremity,  armed  with  a  heavy  cast- 
iron  hammer  d,  descends  with  consider- 
able force  upon  the  anvil  e.  Thus  a  re- 
petition of  mows  is  kept  up  as  long  as 
may  be  required. 
TIN,  is  rather  a  scarce  metal,  found  in 

|  few  parts  of  the  world  in  any  quantity. 

i  Cornwall  is  its  most  productive  source ; 
it  also  occurs  in  the  mountains  between 
Gallicia  and  Portugal,  and  in  those  be- 
tween Saxony  and  Bohemia,  and  in  Cali- 
fornia. Tin  has  also  been  brought  from 
the  peninsula  of  Malacca  in  India,  Borneo, 
and  from  Chili  and  Mexico.  There  are 
only  two  ores  of  tin,  the  native  peroxide, 
and  the  double  sulphuret  of  tin  and  cop- 
per :  the  latter,  sometimes  called  bell- 
metal  ore,  is  extremely  rare  ;  and  it  is  ex- 
clusively from  the  former  that  the  com- 
mercial demands  are  supplied.  In  Corn- 
wall, the  native  peroxide,  or  tin  stone 
(which  is  usually  blended  with  oxides  of 
iron  and  manganese),  occurs  in  veins,  and 
in  loose  grains  and  nodules  in  alluvial 
soil ;  the  latter  is  called  stream  tin,  and 
from  it  the  purest  metal  is  obtained. 
The  ore  is  reduced  by  a  very  simple  pro- 
cess ;  it  is  ground,  washed,  and  roasted 
in  a  reverberatory  furnace ;  it  is  then 
mixed  with  charcoal  or  coke  of  coal  and 
limestone,  and  strongly  heated,  so  as  to 
bring  the  whole  into  fusion,  which  iB 
kept  up  for  eight  or  ten  hours  :  the  lime 
combines  with  the  earthy  matters  of  the 
ore  into  a  fusible  slag,  while  the  coal  re- 
duces the  oxide  to  a  metallic  state,  and 
the  fused  metal  is  drawn  out  at  the  bot- 
tom of  the  furnace  into  a  clay  mould. 
In  this  impure  state  it  is  exposed  to  a 
heat  just  sufficient  to  melt  the  pure  tin, 
which  runs  off  into  a  kettle,  while  the 


646 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tin 


less  fusible  impurities  remain  behind: 
in  the  kettle,  the  tin  is  kept  in  fusion, 
and  agitated  by  plunging  pieces  of  wet 
charcoal  into  it,  which  causes  a  quantity 
of  dross  to  rise  to  the  surface,  where  it  is 
skimmed  off,  and  the  purified  metal  is 
then  cast  into  blocks  of  about  3  cwt. 
each. 

The  stream  tin  is  smelted  by  charcoal ; 
and  the  mass  of  grain  tin  obtained  by 
such  reduction  is  heated  and  let  fall  from 
a  height,  by  which  it  splits  into  masses 
of  a  columnar  fracture,  which  character- 
izes the  pure  metal. 

Pure  tin  is  a  white,  brilliant  metal.  It 
has  a  slight  taste  and  smell  when  rubbed, 
and  its  hardness  is  intermediate  between 
that  of  gold  and  lead.  Its  specific  gravity 
is  7-2.  It  is  very  malleable ;  and  one  of 
its  most  useful  forms  is  that  of  foil, 
which  is  made  by  beating  :  it  is  about  a 
thousandth  of  an  inch  in  thickness.  Its 
ductility  and  tenacity  are  inferior  to  most 
of  the  other  malleable  metals.  A  tin 
wire  78  thousandths  of  an  inch  in  diame- 
ter will  not  support  more  than  38  pounds 
without  breaking.  It  produces  a  pecu- 
liar crackling  noise  when  beat.  Ex- 
posed to  air,  it  soon  becomes  superficially 
oxidized  :  and  when  melted,  successive 
films  of  a  gray  powder  form  upon  its  sur- 
face. The  temperature  at  which  it  melts 
is  about  442°.  At  a  white  heat  it  takes 
fire,  and  burns  with  a  bright  flame.  The 
equivalent  of  tin  is  58.  It  forms  two 
oxides.  The  protoxide  is  thrown  down 
by  alkaline  carbonates  from  an  aqueous 
solution  of  protochloride  of  tin ;  and 
when  dried  and  heated  out  of  the  con- 
tact of  air,  its  water  is  expelled,  and  it 
remains  in  the  form  of  a  dark  substance, 
of  the  specific  gravity  6-6.  It  burns  like 
tinder,  and  becomes  converted  into  the 
peroxide.  It  is  soluble  in  sulphuric  and 
hydrochloric,  and  in  dilute  nitric  acid, 
and  in  the  pure  fixed  alkalies.  Its  salts 
have  a  strong  attraction  for  oxygen,  and 
easily  pass  into  persalts ;  so  that  it  is  a 
powerful  deoxidizing  agent,  and  is  often 
used  as  such  in  some  of  the  chemical  arts. 
When  a  solution  of  protochloride  of  tin  is 
dropped  into  a  solution  of  perchloride  of 
gola,  a  purple  precipitate,  called,  from  its 
inventor,  pvrple  of  Cassius,  is  thrown 
down:  it  appears  to  be  a  compound  of 
peroxide  or  tin  with  protoxide  of  gold, 
and  its  formation  depends  upon  the  de- 
oxidizing power  of  the  solution  of  tin. 
"When  tin  toil  is  put  into  nitric  acid,  there 
is  violent  action,  attended  by  the  decom- 
position of  the  acid  and  the  peroxidize- 
ment  of  the  tin,  which  is  thus  converted 


into  a  white  powder:  this,  when  edul- 
corated and  dried  at  a  red  heat,  acquires 
a  yellow  tint.  It  does  not  easily  form 
permanent  compounds  with  the  acids; 
but  it  unites  with  the  pure  alkalies,  and 
forms  soluble  compounds,  which  have 
sometimes  been  called  stannates,  and  the 
peroxide  itself  stannic  acid.  The  two 
oxides  of  tin  are  respectively  composed  of 
58  tin  and  8  oxygen,  and  58  tin  and  16 
oxygen  :  their  equivalents,  therefore,  are 
66  and  74.  Tin  and  chlorine  also  com- 
bine in  two  proportions  :  the  protochloride 
of  tin  is  formed  by  passing  hydrochloric 
acid  gas  over  metallic  tin'  geiitly  heated 
in  a  glass  tube,  or  by  heating  a  mixture 
of  equal  weights  of  'tin  filings  and  calo- 
mel, when  it  remains,  after  driving  off 
the  mercury,  in  the  form  of  a  gray  solid, 
fusible  at  a  red  heat,  and  volatile  at 
higher  temperatures.  Its  aqueous  solu- 
tion is  commonly  termed  protomvriate  of 
tin.  When  tin  foil  is  heated  in  excess  of 
gaseous  chlorine,  or  when  1  part  of  tin 
filings  is  mixed  with  3  of  corrosive  sub- 
limate and  heated,  a  volatile  liquid  dis- 
tils over,  which  is  perchloride  of  tin,  and 
its  aqueous  solution  forms  the  permvriate. 
Exposed  to  air,  it  is  decomposed  by  the 
aqueous  vapor  of  the  atmosphere,'  and 
exhales  dense  white  fumes  :  hence  called, 
after  its  discoverer,  fuming  liqvor  of 
Libavius.  Both  the  protomuriate  and 
permuriate  of  tin  are  used  by  dyers  and 
calico-printers.  The  former  is  prepared 
by  heating  granulated  tin  in  strong  hy- 
drochloric acid,  as  long  as  hydrogen  con- 
tinues to  be  evolved ;  the  latter,  by 
gradually  dissolving  granulated  tin  in  a 
mixture  of  two  parts  by  measure  of  hy- 
drochloric acid,  one  of  nitric  acid,  and 
one  of  water.  These  chlorides  of  tin  are 
respectively  composed  of  58  tin  and  36 
chlorine,  and  58  tin  and  72  chlorine,  and 
are  therefore  represented  by  the  equiva- 
lents 94  and  130. 

When  melted  tin  and  sulphur  are 
brought  together,  a  black  protosvlphwet 
of  tin  is  formed.  The  bisiuphvret  of  tin 
is  a  yellow  glistening  substance,  some- 
times called  ^Mosaic  gold  (avrum  musi- 
viim),  and  used  in  ornamental  japan- 
work.  It  is  prepared  by  heating  in  a 
glass  retort  2  parts  of  peroxide  of  tin,  2 
of  sulphur,  and  1  of  sal  ammoniac,  and 
maintaining  a  low  red  heat  till  sulphurous 
acid  ceases  to  be  evolved.  The  sulphuret 
and  bisulphuret  of  tin  are  constituted  of 
58  tin  and  16  sulphur,  and  58  tin  and  32 
sulphur  ;  and  have,  therefore,  the  equiv- 
alents 74  and  80. 

TINCAL,  crude  borax. 


tit] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


647 


TIN- FOIL.    (£«  Tin.) 

TIN-PLATE.  The  only  alloy  of  iron 
interesting  to  the  arts  is  that  with  tin,  in 
the  formation  of  tin-plate  or  white-iron. 

The  sheet  iroryntended  for  this  manu- 
facture is  refinedwith  charcoal  instead  of 
coke,  subsequently  rolled  to  various  de- 
grees of  thinness,  and  cut  into  rectangles 
of  different  sizes,  by  means  of  a  shearing- 
machine  driven  by  a  water-wheel,  which 
will  turn  out  100  boxes  a  day,  or  four 
times  the  number  cut  by  hand-labor. 
The  first  step  towards  tinning  is  to  free 
the  metallic  surface  from  every  particle 
of  oxide  or  impurity,  for  any  such  would 
inevitably  prevent  the  iron  'from  alloying 
with  the  tin.  The  plates  are  next  bent 
separately  by  hand  into  a  saddle  or  a 
shape,  and  ranged  in  a  reverberatory 
oven,  so  that  the  flame  may  play  freely 
among  them,  and  heat  them  to  redness. 
They  are  then  plunged  into  a  bath,  com- 
posed of  four  pounds  of  muriatic  acid, 
diluted  with  three  gallons  of  water,  for  a 
few  minutes,  taken  out  and  drained  on 
the  floor,  and  once  more  exposed  to  igni- 
tion in  a  furnace,  whereby  they  are  scaled, 
that  is  to  say,  cast  their  scales.  An 
ordinary  bath  will  suffice  for  scaling  1800 

{)lates.  When  taken  out,  they  are  beaten 
evel  and  smooth  on  a  cast-iron  block, 
after  which  they  appear  mottled  blue  and 
white,  if  the  scaling  has  been  thoroughly 
done.  They  are  next  passed  through 
chilled  rolls  or  cast-iron  cylinders,  render- 
ed very  hard  by  being  cast  in  thick  iron 
moulds.  After  this  process  of  cold  rolling, 
the  plates  are  immersed,  for  ten  or  twelve 
hours,  in  an  acidulous  ley,  made  by  fer- 
menting bran-water,  taking  care  to  set 
them  separately  on  edge,  and  to  turn 
them  at  least  once,  so  that  each  may  re- 
ceive a  due  share  of  the  operation.  From 
this  ley-steep  they  are  transferred  into  a 
leaden  trough,  divided  by  partitions,  and 
charged  with  dilute  sulphuric  acid.  Each 
compartment  is  called  a  hole  by  the  work- 
men, and  is  calculated  to  receive  about 
225  plates,  the  number  afterwards  packed 
up  together  in  a  box.  In  this  liquid  they 
are  agitated  about  an  hour,  till  they  be- 
come perfectly  bright,  and  free  from 'such 
black  spots  as  might  stain  their  surface 
at  the  time  of  immersion.  This  process, 
called  pickling,  is  both  delicate  and  dis- 
agreeable, requiring  a  good  workman,  at 
high  wages.  The  temperature  of  the  last 
two  steeps  should  be  at  least  i»0°  or  100° 
F.,  which  is  kept  up  by  stoves  in  the 
apartments.  The  plates  are  finally  scoured 
with  hemp  and  sand  in  a  body  of  water, 
and  then  put  aside  for  use  in  a  vessel  of 


pure  water,  under  which  they  remain 
bright  and  free  from  rust  for  many 
months,  a  very  remarkable  circumstance. 

The  tinning  follows  these  preparatory 
steps.  A  range  of  rectangular  cast-iron 
pots  is  set  over  a  fire-flue  in  an  apartment 
called  the  stow,  the  workmen  stationing 
themselves  opposite  to  the  narrow  ends. 
The  first  rectangle  in  the  range  is  the 
tin-pot;  the  second  is  the  wash-pot,  with 
a  partition  in  it ;  the  third  is  the  grease- 
pot  ;  the  fourth  is  the  pan,  grated  at  bot- 
tom; the  fifth  is  the  list-pot,  and  is 
greatly  narrower  than  any  of  the  rest : 
they  are  all  of  the  same  length. 

The  prepared  plates,  dried  by  rubbing 
bran  upon  them,  are  first  immersed  one 
by  one  in  a  pot  filled  with  melted  tallow 
alone,  and  are  left  there  for  nearly  an 
hour.  They  are  thence  removed,  with 
the  adhering  grease,  into  the  first  pot, 
filled  with  a  melted  mixture  of  block  and 
grain  tin,  covered  with  about  four  inches 
of  tallow,  slightly  carbonized.  This  pot 
is  heated  by  a  fire,  playing  under  its  bot- 
tom and  round  its  sides,  till  the  metal  be- 
comes so  hot  as  nearly  to  inflame  the 
grease.  Here  about  340  plates  are  ex- 
posed, upright,  to  the  action  of  the  tin 
4or  an  hour  and  a  half,  or  more,  according 
to  their  thickness.  They  are  next  lifted 
out,  and  placed  upon  an' iron  grating,  to 
let  the  superfluous  metal  drain  off;"  but 
this  is  more  completely  removed  in  the 
next  process,  called  washing. 

The  plates  are  then  dipped  in  the  pot 
containing  the  melted  metal.  They  are 
then  lifted  out  with  tongs,  rubbed  with  a 
brush,  re-dipped  in  the  tin,  and  then  im- 
mersed in  the  grease-pot.  It  is  dipped  a 
third  time,  and  the  rim  of  tin  removed 
from  the  under  edge  of  the  plate  by  dip- 
ping the  edge  in  melted  metal,  when  the 
superfluous  metal  becomes  detached. 
They  are  finally  rubbed  with  bran  to  free 
them  from  tallow,  and  then  packed  up  in 
boxes. 

Crystallized  tin-plate,  (see  Moiree  Me- 

TALLTQUE.) 

TITANIUM.  A  rare  metal,  discovered 
by  Gregor  in  a  mineral  from  Cornwall 
called  menachanite.  Its  characters  were 
first  ascertained  by  Klaproth,  who  gave 
it  the  above  name.  In  the  year  1822,  Dr. 
Wollaston  ascertained  that  the  minute 
copper  -  colored  crystals,  occasionally 
found  in  the  slag  of  the  iron-smelting 
furnaces  at  Merthyr  and  elsewhere,  were 
pure  titanium  ;  and  it  is  to  him  that  we 
are  indebted  for  a  precise  account  of  its 
properties.  In  this  state  it  has  a  copper 
color    is   extremely   infusible,    and  of  a 


648 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tob 


specific  gravity  of  5-8  ;  it  is  so  hard  as  to 
scratch  not  only  glass,  but  crystal.  It 
resists  the  action  of  air  and  acids,  but  is 
oxidized  by  the  action  of  nitre  at  a  red 
heat.  Titanium  appears  susceptible  of 
two  degrees  of  oxidizement.  The  protox- 
ide of  titanium  is  blue  or  purple,  and  ap- 
pears to  constitute  the  mineral  called  an- 
atase.  The  peroxide,  or  titanic  acid, 
exists  nearly  pure  in  titanite  or  rutilite, 
and  is  combined  with  the  oxides  of  iron 
and  manganese  in  menachanite. 

TOBACCO.  The  dried  leaves  of  the 
Nicotiana  tabacum,  a  plant  indigenous  to 
this  continent,  but  which  succeeds  very 
well,  and  is  extensively  cultivated,  in 
most  parts  of  the  Old  World.  The  recent 
leaves  possess  very  little  odor  or  taste; 
but  when  dried,  their  odor  is  strong, 
narcotic,  and  somewhat  foetid ;  their  taste 
bitter,  and  extremely  acrid.  When  well 
cured,  they  are  of  a  yellowish  green  color. 
When  distilled,  they  yield  an  essential 
oil,  on  which  their  virtue  depends,  and 
which  is  said  to  be  a  virulent  poison. 
The  leaves  are  used  in  various  ways,  be- 
ing chewed,  smoked,  and  ground,  and 
manufactured  into  snuff.  It  is  in  the  last- 
mentioned  form  that  tobacco  is  princi- 
pally used  in  Great  Britain,  and,  though, 
the  "contrary  has  often  been  asserted,  its 
use  does  not  seem  to  have  been  produc- 
tive of  any  perceptible  bad  consequence. 

The  term  tobacco  is  probably  derived 
from  Tabaco,  a  province  of  Yucatan, 
where  it  was  first  found  by  the  Spaniards. 
To  Sir  Francis  Drake  and  Sir  Walter 
Baleigh  has  been  ascribed  the  honor  of 
having  introduced  it  into  England,  nearly 
three  centuries  ago. 

For  some  years  past  it  is  believed,  so 
far  as  can  be  ascertained,  there  has  been 
a  comparative  falling  off  of  the  tobacco 
crop  or  the  country.  The  reason  of  this  is 
to  be  found  probably  in  the  fact  of  the  ex- 
haustion of  the  hinds  devoted  to  this  pro- 
duct in  the  largest  tobacco  growing  regions 
of  the  Atlantic  States ;  especially  of  Mary- 
land, Virginia,  and  South  Caroiina,  while 
there  has  not  been,  as  in  the  case  of  the 
cotton  crop,  sufficient  additional  lands  in 
the  other  parts  of  the  country  brought 
into  cultivation  to  supply  the  deficiency. 
It  is  capable  of  being  raised  in  every 
state  in  the  Union  ;  and  a  large  breadth 
of  land  is  laid  out  for  it  so  far  north  as 
New  York.  When  the  plants  are  green, 
they  are  dried  for  keeping. 

The  plants  are  hung  up  to  dry  during 
four  or  five  weeks  ;  taken  down  out  of  the 
sheds  in  damp  weather,  for  in  dry  they 
would  be  apt  to  crumble  into  pieces; 


stratified  in  heaps,  covered  up,  and  left 
to  sweat  for  a  week  or  two  according  to 
their  quality  and  the  state  of  the  season  ; 
during  which  time  they  must  be  examin- 
ed frequently,  opened  up,  and  turned 
over,  lest  they  become  too  hot,  take  fire, 
or  run  into  putrefactive  fermentation. 
This  process  needs  to  be  conducted  by 
skilful  and  attentive  operatives.  An  ex- 
perienced man  can  form  a  sufficiently  ac- 
curate judgment  of  the  temperature,  by 
thrusting  his  hand  down  into  the  heap.* 
According  to  the  recent  analysis  of 
Possett  and  Reimann,  10,000  parts  of 
tobacco-leaves  contain — 6  of  the  peculiar 
chemical  principle  nicotine;  1,  of  nico- 
tianine;  287  of  slightly  bitter  extractive; 
174  of  gum,  mixed  with  a  little  malic 
acid  ;  26*7  of  a  green  resin  ;  26  of  vege- 
table albumen;  104*8  of  a  substance  anal- 
agous  to  gluten;  51  of  malic  acid  ;  12  of 
malate  of  ammonia;  48  of  sulphate  of 
potassa ;  6*8  of  chloride  of  potassium  ; 
9-5  of  potassa,  which  had  been  combined 
with  malic  and  nitric  acids  ;  16-6  of  phos- 

Ehate  of  lime ;  24-2  of  lime,  which  had 
een  combined  with  malic  acid;  8-8  of 
silica ;  496-9  of  fibrous  or  ligneous  mat- 
ter; traces  of  starch;  and  88-28  of 
water. 

Nicotine  is  a  transparent  colorless  liquid, 
of  an  alkaline  nature.  It  may  be  distilled 
in  a  retort  plunged  into  a  bath  heated  to 
290  Fahrenheit.  It  has  a  prickling,  burn- 
ing taste,  which  is  very  durable  ;  and  a 
pungent,  disagreeable  "smell.  It  burns 
by  means  of  a  wick,  with  the  diffusion  of 
a  vivid  light,  and  much  smoke.  It  may 
be  mixed"  with  water  in  all  proportions. 
It  is  soluble  also  in  acetic  acid,  oil  of 
almonds,  alcohol,  and  ether,  but  not  in 
oil  of  turpentine.  It  acts  upon  the  ani- 
mal economy  with  extreme  violence  ;  and 
in  the  dose  of  one  drop  it  kills  a  dog.  It 
forms  salts  with  the  acids.  About  one 
part  of  it  may  be  obtained  by  very  skilful 
treatment  from  one  thousand  of  good 
tobacco. 

The  tobacco  raised  in  1847  in  the  Unit- 
ed States,  amounted  to  220,164,000  lbs., 
valued  at  $11,008,220.  For  1848,  it  was— 
produce  218,909,000  lbs.;  value  $8,756,860. 

The  exports  during  the  same  were,  in 
value — 

1847 87,242.086 

1848 7,551,122 

TOBACCO-PIPES  are  made  of  a  fine- 
grained plastic  white  clay,  to  which  they 
have  given  the  name.  It  is  worked  with 
water  into  a  thin  paRte,  which  is  allowed  to 
settle  in  pits,  or  it  may  be  passed  through 
a  sieve,  to  separate  the  silicious  or  other 


tor] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


649 


stony  impurities  ;  the  water  is  afterwards 
evaporated  till  the  clay  hecome3  of  a 
doughy  consistence,  when  it  must  be 
well  kneaded  to  make  it  uniform.  The 
clay  is  distinguished  by  its  perfectly 
white  color,  and  its  great  adhesion  to  the 
tongue  after  it  is  baked;  owing  to  the 
large  proportion  of  alumina  which  it  con- 
tains. 

A  child  fashions  a  ball  of  clay  from  the 
heap,  rolls  it  out  into  a  slender  cylinder 
upon  a  plank,  with  the  palms  of  his 
hands,  in  order  to  form  the  stem  of  the 
pipe.  He  sticks  a  small  lump  to  the  end 
of  the  cylinder  for  forming  the  bowl ; 
which  having  done,  he  lays  the  pieces 
aside  for  a  day  or  two,  to  get  more  con- 
sistence. In  proportion  as  he  makes 
these  rough  figures,  he  arranges  them  by 
dozens  on  a  board,  and  hands  them  to 
the  pipemaker. 

The  pipe  is  finished  by  means  of  a 
folding  brass  or  iron  mould,  channelled 
inside  of  the  shape  of  the  stem  and  the 
bowl,  and  capable  of  being  opened  at  the 
two  ends.  It  is  formed  of  two  pieces, 
each  hollowed  out  like  a  half-pipe,  cut  as 
it  were  lengthwise  ;  and  these  two  jaws, 
when  brought  together,  constitute  the 
exact  space  for  making  one  pipe.  There 
are  small  pins  in  one  side  ot  the  mould, 
corresponding  to  the  holes  in  the  other, 
which  serve  as  guides  for  applying  the 
two  together  with  precision. 

The  workman  takes  a  long  iron  wire, 
with  its  end  oiled,  and  pushes  it  through 
the  soft  clay  in  the  direction  of  the  stem, 
to  form  the  bore,  and  he  directs  the  wire 
by  feeling  with  his  left  hand  the  progress 
of  its  point.  He  lays  the  pipe  in  the 
groove  of  one  of  the  jaws  of  the  mould, 
with  the  wire  sticking  in  it ;  applies  the 
other  jaw,  brings  them  smartly  together, 
and  unites  them  by  a  clamp  or  vice, 
which  produces  the  external  form.  A 
bver  is  now  brought  down,  which  presses 
an  oiled  stopper  into  the  bowl  of  the 
pipe,  while  it  is  in  the  mould,  forcing  it 
sufficiently  down  to  form  the  cavity ;  the 
wire  being  meanwhile  thrust  backwards 
and  forwards  so  as  to  pierce  the  tube 
completely  through.  The  wire  is  now 
withdrawn,  the  jaws  of  the  mould  open- 
ed, the  pipe  taken  out,  and  the  redun- 
dant clay  removed  with  a  knife.  After 
drying  for  a  day  or  two,  the  pipes  are 
scraped,  polished  with  a  piece  of  hard 
wood,  ana  the  stems  being  bent  into  the 
desired  form,  they  are  carried  to  the 
baking  kiln.  The  pipes  arc  then  put  in 
the  furnace  or  kiln  and  baked,  removed 
to  receive  the  glaze  (in  some  instances),  | 


and  again  returned  to  the  furnace  till 
the  glaze  has  melted  over  the  bowl. 

TOMBAC.  An  alloy  of  copper  and 
zinc,  or  a  species  of  brass  with  excess  of 
zinc.  When  arsenic  is  added,  it  forms 
white  tombac. 

TOOTHING.  In  architecture,  bricks 
alternately  projecting  at  the  end  of  a  wall, 
in  order  that  they  may  be  bonded  into  a 
continuation  of  it  when  the  remainder  is 
carried  up. 

TOPAZ.  A  crystallized  mineral  hard- 
er than  quartz,"  of  a  yellow  or  wine 
color,  composed  of  60  alumina,  35  silica, 
5  fluoric  acid.  When  heated,  the  Bra- 
zilian topaz  becomes  rose-red,  and  is 
sometimes  in  this  state  passed  off  as  a 
ruby :  the  Saxon  topaz  loses  its  color  by 
heat.  When  without  flaws  and  of  a  good 
color,  it  is  much  employed  in  jewelry. 
The  Saxon  is  usually  paler  than  the  Bra- 
zilian, which  often  has  a  pinkish  hue ; 
the  Siberian  topaz  is  usually  colorless, 
and  the  Scotch  has  a  blue  tinge. 

TOPAZOLITE.  A  sub-variety  of  garnet 
of  a  pale-yellow  color,  found  in  Piedmont. 
It  is  a  silicate  of  alumina,  lime,  and  iron, 
with  traces  of  glucina  and  manganese. 

TOEREFACTION.  The  operation 
of  roasting  ores  to  deprive  them  of 
sulphur,  arsenic,  or  other  volatile  ingre- 
dients. When  drugs  are  highly  dried, 
or  partially  toasted  or  roasted,  they  are 
also  said  to  be  torrefied. 

TORSION,  in  mechanics,  is  the  twisting 
or  wrenching  of  a  body  by  the  exertion  of  a 
lateral  force.  If  a  slender  rod  of  metal 
suspended  vertically,  and  having  its  up- 
per end  fixed,  be  twisted  through  a  cer- 
tain angle  by  a  force  acting  in  a  plane 
perpendicular  to  its  axis,  it  will,  on  the 
removal  of  the  force,  untwist  itself,  or 
return  in  the  opposite  direction  with  a 
greater  or  less  velocity,  and,  after  a  series 
of  oscillations,  will  come  to  rest  in  its 
original  position.  The  limits  of  torsion 
within  which  the  body  will  return  to  its 
original  state  depends  upon  its  elasticity. 
A  fine  wire,  of  ti  few  feet  in  length,  may 
be  twisted  through  several  revolutions 
without  impairing  its  elasticity  ;  and 
within  those  limits  the  force  evolved  is 
found  to  be  perfectly  regular,  and  direct- 
ly proportional  to  the  angular  displace- 
ment from  the  position  of  rest.  If  the 
angular  displacement  exceeds  a  certain 
limit,  the  particles  of  the  body  will  be 
wrenched  asunder ;  or  if  the  elasticity  is 
not  perfect  (as  in  a  wire  of  lead,  for  ex- 
ample, before  disruption  takes  place),  the 
particles  will  assume  a  new  arrangement, 
or  take  a  set,  and  will  not  return  to  their 


650 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[TOR 


original  position  on  the  withdrawal  of  the 
disturbing  force. 

The  resistance  which  cylinders  or 
prisms  formed  of  different  substances 
oppose  to  torsion,  furnishes  one  of  the 
usual  methods  of  determining  the  elasti- 
city and  strength  of  materials  ;  and  the 
property  which  a  metallic  wire  or  thread 
stretched  by  a  small  weight  possesses  of 
becoming  twisted  and  untwisted  in  a 
series  of  isochronous  and  perfectly  regu- 
lar oscillations,  has  been  ingeniously  ap- 
plied in  the  torsion  balance  to  the  mea- 
surement of  very  minute  forces,  and 
thereby  to  the  establishment  of  the  fun- 
damental laws  of  electricity  and  magnet- 
ism, and  to  the  determination  of  the 
mean  density  of  the  earth.  {See  Balance 
or  Torsion.) 

The  laws  of  torsion  have  been  experi- 
mentally investigated  by  Coulomb  in  a 
variety  of  substances  ;  as  metallic  wires, 
hairs,  fibres  of  silk,  &c.  The  method 
which  he  employed  consisted  in  attach- 
ing a  body  of  given  form  and  dimensions 
to  the  extremity  of  the  wire,  and,  after 
twisting  it  through  a  certain  angle,  to 
abandon  it  to  the  action  of  the  force 
evolved,  and  observe  the  time  of  the 
oscillations.  The  following  general  laws 
were  found  to  hold  good  : 

1.  On  loading  a  wire  or  thread  with 
different  weights,  it  will  settle  in  different 
positions  of  stability ;  that  is  to  say,  an 
index  attached  to  the  weight  will  point 
in  different  directions  if  the  weight  be 
varied,  and  the  angular  deviation  may 
amount  even  to  a  whole  circumference. 

2.  The  oscillations  are  isochronous. 

3.  The  time  of  oscillation  is  propor- 
tional to  the  square  root  of  the  weight 
which  stretches  the  wire. 

4.  The  time  of  oscillation  is  as  the 
square  root  of  the  length  of  the  wire. 

5.  The  time  of  oscillation  is  inversely 
as  the  square  of  the  diameter  of  the  wire. 

TORTOISE-SHELL,  or  rather  scales, 
a  horny  substance  that  covers  the  hard 
strong  covering  of  a  bbny  contexture, 
which  incloses  the  Testudo  imbricata, 
Linn.  The  lamellae  or  plates  of  this  tor- 
toise are  13  in  number,  and  may  be  readi- 
ly separated  from  the  bony  part  by  placing 
fire  beneath  the  shell,  whereby  they  start 
asunder.  They  vary  in  thickness  from 
one-eighth  to  one-quarter  of  an  inch,  ac- 
cording to  the  age  and  size  of  the  animal, 
and  weigh  from  5  to  25  pounds.  The 
larger  the  animal,  the  better  is  the  shell. 
This  substance  may  be  softened  by  the 
heat  of  boiling  water  ;  and  if  compressed 
in  this  state  by  screws  in  iron  or  brass 


moulds,  it  may  be  bent  into  any  shape. 
The  moulds  being  then  plunged  in  cold 
water,  the  shell  becomes  fixed  in  the 
form  imparted  by  the  mould.  If  the 
turnings  or  filings  of  tortoise-shell  be 
subjected  skilfully  to  gradually  increased 
compression  between  moulds  immersed 
in  boiling  water,  compact  objects  of  any 
desired  ornamental  figure  or  device  may 
be  produced.  The  soldering  of  two  pieces 
of  scale  is  easily  effected,  by  placing  their 
edges  together,  after  they  are  nicely  filed 
to  one  bevel,  and  then  squeezing*  them 
strongly  between  the  long  flat  jaws  of 
hot  iron  pincers.  The  pincers  should  be 
just  hot  enough  to  brown  paper  slightly, 
without  burning  it.  They  may  be  sol- 
dered also  by  the  heat  of  boiling  water, 
applied  along  the  edges  with  skilful  pres- 
sure. But  in  whatever  way  this  process 
is  attempted,  the  surfaces  to  be  united 
should  be  made  very  smooth,  level,  and 
clean ;'  the  least  foulness,  even  the  touch 
of  the  finger,  or  breathing  upon  them, 
would  prevent  their  coalescence. 

Tortoise-Shell,  is  manufactured  in 
various  objects,  partly  by  cutting  out 
the  shapes,  and  partly  by  agglutinating 
portions  of  the  shell  by  heat."  When  the 
shell  has  become  soft  by  dipping  it  in 
hot  water,  the  edges  are  in  the  cleanest 
possible  state,  without  grease,  pressed 
together  with  hot  flat  tongs,  and  then 
plunged  into  cold  water,  to  fix  them  in 
their  position.  The  teeth  of  the  larger 
combs  are  parted  in  their  heated  state, 
or  cut  out  with  a  thin  frame-saw,  while 
the  shell,  equal  in  size  to  two  combs, 
with  their  teeth  interlaced,  is  bent  like 
an  arch  in  the  direction  of  the  length  of 
the  teeth.  The  shell  is  then  flattened, 
the  points  are  separated  with  a  narrow 
chisel  or  pricker,  and  the  two  combs  are 
finished,  while  flat,  with  coarse  single- 
cut  files  and  triangular  scrapers.  They 
are  finally  warmed,  and  bent  on  the  knee 
over  a  wooden  mould,  bv  means  of  a 
strap  passed  round  the  foot,  just  as  a 
shoemaker  fixes  his  last.  Smaller  combs 
of  horn  and  tortoise-shell  are  parted, 
while  flat,  by  an  ingenious  machine,  with 
two  chisel-formed  cutters  placed  oblique- 
ly, so  that  each  cut  produces  one  tooth. 
(See  Rogers1  ComVcutting  Machine, 
Trans.  Soc.  Arts  vol.  xlix.,  part  2,  since 
improved  by  Mr.  Kelly.)  In  making  the 
frames  for  eye-glasses,  spectacles,  &c, 
the  apertures  for  the  glasses  were  for- 
merly cut  out  to  the  circular  form,  with 
a  tool  something  like  a  carpenter's  cen 
tre-bit,  or  with  a  crown-saw  in  the  lathe. 
The  discs  so  cut  out  were  used  for  vw 


tun] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


651 


laying  in  the  tops  of  boxes,  &c.  This 
required  a  piece  of  shell  as  large  as  the 
front  of  the  spectacle  ;  but  a  piece  one- 
third  of  the  size  will  now  suffice,  as  the 
eyes  are  strained  or  pulled.  A  long  nar- 
row piece  is  cut  out,  and  two  slits  are 
made  in  it  with  a  saw.  The  shell  is  then 
warmed,  the  apertures  are  pulled  open, 
and  fastened  upon  a  taper  triblet  of  the 
appropriate  shape.  The  groove  for  the 
edge  of  the  glass  is  cut  with  a  small  cir- 
cular cutter,  or  sharp-edged  saw,  about 
three-eighths  or  halt  an  inch  in  diame- 
ter ;  and  the  glass  is  sprung  in  when  the 
frame  is  expanded  by  neat. 

TRACING-PAPER,  is  made  by  wash- 
ing tissue-paper  with  a  mixture  of  equal 
parts  of  spirits  of  turpentine  and  mastic- 
varnish,  the  transparency  being  as  the 
varnish. 

Artisans  transfer  drawings  to  wood, 
by  laying  paper  covered  with  soft  red 
chalk,  or  pipe-clay,  on  the  wood,  and 
then  following  the  "lines  on  tracing-paper 
with  a  hard  point,  so  as  to  impress  the 
same,  through  the  red  paper  on  the 
wood.  This  nearly  resembles  the  simi- 
lar practice  in  engraving.  (Se#  Litho- 
graphy.) 

TRAGACANTH.  A  variety  of  gum  : 
it  is  the  produce  of  the  Astragalus  Tra- 
gacantha,  a  native  of  Africa,  and  import- 
ed in  small  twisted  or  flattened  pieces, 
white  or  yellowish,  and  translucent  or 
nearly  opaque.  When  put  into  water 
they  swell  up,  and  gradually  form  a  gela- 
tinous or  pasty  mass ;  not  dissolving  into 
a  clear  solution,  as  is  the  case  with  gum 
arabic.  An  analogous  kind  of  gum  is 
found  in  other  plants,  and  the  generic 
name  of  tragacanthin  is  sometimes  ap- 
plied to  it. 

It  forms  a  paste  which  does  not  crack, 
nor  readily  ferment,  and  hence  is  put  on 
postasre-stamps,  labels,  &c 

TRANSPARENT  BLINDS,  are  paint- 
ed with  transparent  colors  on  stretched 
cambric,  prepared  by  a  coat  of  hot  solu- 
tion of  isinglass  or  parchment-glue. 
The  transparent  colors  are  lake,  prus- 
sian-blue,  umber,  sienna,  and  vandyke- 
brown  ;  and,  other  colors  are  made  semi- 
transparent  when  ground  with  the  mastic 
varnish  used  in  blind-painting. 

Transparent  blinds  are  also  elegantly 
made  by  perforating,  or  punching  with 
a.  machine,  thin  sheets  of  metal,  with 
such  numerous  holes  that  vision  is  not 
obstructed  by  the  intermediate  divisions. 
They  are  now  in  general  use.  The  same 
machine  has  also  been  applied  to  make 
lanterns,  cullenders,  strainers,  dredgers, 


&c.    Wire  gauze  forms  the  usual  trans- 
parent blinds. 

TRANSPLANTATION,  is  an  opera- 
tion whose  success  depends  on  the  plant 
being  torpid,  and  on  its  spongioles  being 
uninjured.  If  it  be  growing,  or  ever- 
green, and  the  spongioles  are  uninjured, 
the  removal  will  produce  no  injury  ex- 
cept the  temporary  suspension  of  the 
action  of  the  spongioles.  Old  trees  in 
which  the  roots  are  much  injured  form 
new  ones  so  slowly,  that  they  are  liable 
to  be  exhausted  of  sap  by  the  absorption 
of  numerous  young  buds  before  new 
spongioles  can  be  formed.  The  amputa- 
tion of  their  upper  extremities  is,  there- 
fore, the  most  probable  prevention  of 
death  ;  but  in  most  cases  injury  to  the 
roots  is  fatal. 

TRIPOLI.  A  mineral  used  for  polish- 
ing, originally  from  Tripoli  in  Barbary. 
It  occurs  in  friable  earthy  masses  of" a 
dull  clay  color.  Its  essential  components 
are  silica,  alumina,  and  oxide  of  iron; 
but  the  varieties  of  tripoli  appear  to  vary 
extremely  in  composition.  Ehrenberg  has 
found  the  different  tripolis  to  be  aggre- 
gates of  silicified  animalcules.  It  is  yel- 
low-gray, or  dirty-white  in  color,  and 
does  not  adhere  to  the  tongue. 

According  to  the  chemical  analysis  of 
Bucholz,  tripoli  consists  of — silica,  81 ; 
alumina,  1-5  ;  oxide  of  iron,  8  ;  sulphuric 
acid,  3-45;  water,  4-55.  This  specimen 
was  probably  found  in  a  coal-field.  The 
tripoli  of  Corfu  is  reckoned  the  best  for 
scouring  or  brightening  brass  and  other 
metals.     (See  Polishing.) 

TUFA,  or  TUF.  A  gray  deposit  of 
calcareous  carbonate,  from  springs  and 
streams,  generally  incrusting  twigs  and 
roots  of  plants  in  water. 

TULA  METAL.  An  alloy  of  silver, 
copper,  and  lead. 

TUNGSTEN.  A  peculiar  metal,  which 
occurs  in  the  state  of  an  acid  (the  tungs- 
tic),  combined  with  various  bases  —  as 
with  lime,  the  oxides  of  iron,  manganese, 
and  lead.  The  metal  is  obtained  by  re- 
duction of  the  ore,  or  the  deoxidizement 
of  the  acid,  in  the  form  of  a  dark  steel- 
gray  powder,  which  assumes  under  the 
burnisher  a  feeble  metallic  lustre.  Its 
specific  gravity  is  17*22. 

TUNNEL.  In  engineering,  a  subter- 
ranean passage  cut  through  a  hill  or 
under  a  river,  for  the  purpose  of  carry- 
ing a  canal,  road,  railway,  &c. 

In  the  construction  of  railways  and 
canals,  it  is  sometime*  absolutely  neces- 
sary, and  very  frequently  expedient,  to 
have    recourse  to  tunnelling,  either  to 


652 


CYCLOPEDIA    OF    THE    USEFUL  ARTS. 


preserve  the  requisite  level,  or  shorten 
the  distance,  or  to  lessen  the  expense  of 
open  cutting.  The  circumstances  on 
which  the  question  of  expediency  de- 
pends, are  often  of  a  very  complicated 
nature ;  but,  generally  speaking,  it  must 
be  decided  by  considerations  of  economy, 
for  in  the  present  state  of  engineering,  a 
tunnel  may  be  made  of  almost  any  length, 
and  through  materials  of  any  descrip- 
tion, from  a  granite  rock  to  a  quicksand. 
The  nature  of  the  ground  can  hardly  be 
said  to  interpose  any  farther  obstacle 
than  what  may  be  occasioned  by  the 
expense. 

One  of  the  greatest  tunnels  in  the 
world,  is  that  under  the  river  Thames 
below  London  Bridge — a  short  notice  of 
it  is  here  inserted. 

Some  previous  attempts  had  been 
made  to  carry  a  tunnel  under  the  river 
below  London  Bridge.  In  1799,  one  was 
projected  at  Gravesend ;  but  the  project 
was  soon  abandoned.  In  1804,  another 
was  attempted  from  Rotherhithe  to  Lime- 
house.  A  shaft  of  11  feet  in  diameter 
was  sunk  to  the  depth  of  42  feet,  and 
continued  at  a  reduced  diameter  of  8  feet 
to  the  depth  of  76  feet,  whence  a  drift 
was  carried  923  feet  under  the  river,  and 
to  within  150  feet  of  the  opposite  shore, 
where  difficulties  of  so  formidable  a  na- 
ture arose  that  the  engineer  reported 
farther  progress  to  be  impossible.  The 
scheme,  however,  continued  to  be  agi- 
tated ;  and  in  1823,  Mr.  Brunei  proposed 
a  plan  which  has  at  length  been  carried 
successfully  into  execution. 

The  act  of  parliament  authorizing  the 
operation  was  obtained  in  June,  1824, 
and  shortly  after  the  work  was  com- 
menced at  Kotherhithe.  The  shaft  at 
this  place  is  150  feet  from  the  river.  It 
was  formed  by  building  a  cylinder  of 
brickwork  50  feet  in  diameter,  42  feet  in 
height,  and  3  feet  in  thickness,  on  the 
top  of  which  a  steam  engine  was  erected 
for  raising  the  water  and  earth.  The 
cylinder  was  let  down  bodily  into  the 
ground,  forcing  its  way  through  a  bed  of 
gravel  and  sand  26  feet  deep,  and  full  of 
land  water.  The  shaft  was  sunk  to  the 
depth  of  65  feet,  and  from  this  level 
another  smaller  shaft,  25  feet  in  diameter, 
was  sunk,  destined  to  be  a  well  or  reser- 
voir for  the  drainage  of  water.  The  ex- 
cavation for  the  body  of  the  tunnel  was 
commenced  at  a  depth,  of  63  feet,  and 
was  carried  on  at  a  declivity  of  2  feet  and 
8  inches  per  100  feet,  in  order  to  have 
sufficient  thickness  of  ground  to  pass 
safely  under  the  river.    The  excavation 


is  38  feet  in  breadth,  and  22£  feet  in 
height,  presenting  a  sectional  area  of  850 
feet ;  and  the  base,  at  the  deepest  part  of 
the  river,  is  76  feet  below  high- water 
mark.  The  body  of  the  tunnel  is  of 
brickwork  in  Roman  cement. 

In  the  neighborhood  of  the  city  of 
Buffalo,  N.  Y.,  is  the  tunnel  of  the  Water 
Works  Company  in  the  rock  under  the 
Erie  Canal  and  the  Black  Bock  harbor  to 
the  Niagara  river,  about  half  a  mile  be- 
yond the  city  line. 

The  perpendicular  shaft  or  well  is 
about  8  feet  in  diameter  and  30  feet  deep, 
nearly  the  whole  being  through  rock. 
From  the  bottom  of  the  well  starts  the 
tunnel,  which  is  nearly  circular,  and  about 
6s  feet  in  diameter,  running  nearly  hori- 
zontally towards  the  bed  of  the  river, 
which  is  distant  about  360  feet.  A  slight 
slope  upward,  as  the  tunnel  advances, 
allows  the  water  which  pours  into  it  from 
springs  or  crevices  in  the  rock,  to  run 
back  into  the  well  out  of  the  way  of  the 
workmen  who  are  engaged  incessantly, 
day  and  night,  in  blasting  the  rock.  They 
have  now  (1851)  proceeded  about  280  feet 
from  the  well,  progressing  at  about  2  feet 
per  day.  Only  four  of  the  miners  em- 
ployed are  able  to  work  at  once,  changing 
three  times  during  the  twenty-four  hours. 
The  work  is  all  done  by  lamp-light. 

The  Railroad  Tunnel  at  New  Ilamburg, 
N.  Y.,  is  830  feet  long,  and  through  so- 
lid rock.  At  the  south  end  is  a  cut  500 
feet  loug,  30  feet  wide,  and  50  feet  deep, 
all  through  the  rock  before  reaching  the 
tunnel;  through  two  shafts  sunk  to  it, 
one  70  feet  in  depth,  the  other  56,  a 
glimpse  of  daylight  may  be  obtained. 
Emerging  at  the  north  end  one  other 
deep  cut  is  found,  nearly  as  formidable 
as  that  at  the  south,  being  200  feet  long 
and  70  deep,  making  the  entire  deep  cut- 
ting through  the  rock,  all  inclusive,  no 
less  than  1530  feet. 

To  carry  on  this  work  Messrs.  Ward, 
Wells  &  Co.,  the  contractors,  employ  400 
men,  keep  in  steady  operation  nine  black- 
smiths' shops  with  two  fires  each,  to  re- 
pair and  temper  tools,  have  12,000  lbs. 
of  cast  steel  in  drills  and  tools  in  constant 
use,  and  have  consumed  6000  kegs  of 
powder,  of  25  lbs.  each,  in  fourteen 
months.  The  tunnel  is  19  feet  hit'li  and 
24  feet  wide,  where  finished,  and  will  be 
so  all  the  way  through.  It  is  not  yet 
completed. 

The  Great  Tunnel,  of  the  Baltimore 
and  Ohio  Railroad,  is  one  of  the  greatest 
works  of  civil  engineering  now  going  on 
in  this  country.     It  is  a  few  miles  from 


tur] 


CYCLOPEDIA    OF    THE    USEFUL   ARTS. 


653 


Morgantown,  West  Virginia,  and  is 
through  a  mountain  (for  a  rail-track)  a 
mile  and  a  quarter  wide.  There  are  al- 
ready sunk  three  shafts,  some  20  by  19 
feet,  and  from  175  to  185  deep. 

The  Huddersfield  and  Manchester  Kail- 
road  Tunnel,  in  England,  is  more  than 
three  miles  in  length,  being  the  largest 
in  the  world,  at  a  depth  of  025  feet  below 
the  ridge  of  the  hill,  which  it  pierces. 
The  tunnel  is  so  perfectly  straight  that 
on  a  clear  day  one  can  see  through  from 
either  end. 

In  France,  there  is  an  extensive  tunnel 
three  mile*  in  length,  on  the  railroad  be- 
tween Marseilles  and  Avignon.  Its  height 
is  30  feet,  and  width  24  feet,  and  its  depth 
below  the  surface  of  the  ground  600  feet. 

The  cost  of  tunneling  was,  $2,040,000. 

TURBINE.     {See  Whekls,  Water.) 

TURF.     (See  Fuel  and  Peat.) 

TURMERIC.  The  root  of  the  Curcuma 
longa.  This  root  yields  a  fine  yellow 
powder,  which  is  occasionally  used  as  a 
aye-stuff  in  medicine;  it  also  forms  one 
of  the  ingredients  of  curry  powder.  Paper 
stained  with  turmeric  is  often  used  in  the 
chemical  laboratory  as  a  test  of  the  pre- 
sence of  free  alkalies  and  their  carbonates, 
by  which  its  yellow  color  is  converted  to 
brown.    It  is  also  used  ta  color  butter. 

TURNING  is  a  very  ingenious  and 
useful  art,  by  which  a  great  variety  of  ar- 
ticles are  manufactured,  by  cutting  or 
fashioning  them  while  they  revolve  upon 
an  axis.  Every  solid  substance  in  nature 
may  be  submitted  to  this  process  ;  and, 
accordingly,  we  have  articles  turned  in 
the  metals,  in  wood,  in  pottery,  in  stone, 
in  ivory,  &c.  Among  the  great  varieties 
of  lathes,  it  is  indispensably  required,  for 
circular  turning,  that  the  work  should  be 
supported  by  two  steady  centres,  or  by 
parts  equivalent  to  two  centres,  at  a  dis- 
tance from  each  other  in  the  axis  of  rota- 
tion, and  that  the  tool  should  be  support- 
ed by  a  steady  bar,  or  a  piece  called  the 
rest. 

Clock  and  watch-makers  use  a  very 
cheap,  simple,  and  portable  lathe,  called 
a  turns-bench,  consisting  of  a  straight  bar 
of  iron,  about  five  inches  long,  with  two 
cross  bars  or  heads,  about  two  inches 
Ion?,  one  fixed  at  the  end  of  the  long  bar, 
and  the  other  capable  of  being  shifted  by 
means  of  a  socket  and  screw.  In  each  of 
these  heads  is  a  centre-pin,  terminating 
in  a  point  at  one  end,  and  in  a  central 
hole  at  the  other,  like  the  centre-pin  in 
the  poppet-head  of  any  other  lathe  ;  the 
use  of  which  is  to  afford  point  centres 
when  the  points  are  turned  towards  each 


other,  or  hole  centres  when  the  contrary 
is  the  case ;  and,  lastly,  there  is  a  small 
rest,  with  its  support,  slidable  and  ad- 
justable along  the  bar,  as  in  another 
lathe.  These  instruments  will,  there- 
fore, support  any  piece  of  four  or  five 
inches  long,  and  three  inches  diameter, 
between  the  centres ;  and  the  method  of 
producing  the  rotation  is  by  passing  the 
cat-gut  string  of  a  bow  once  or  twice 
round  the  work,  and  drawing  the  bow 
backwards  and  forwards  with  one  hand, 
while  the  other  is  employed  in  applying 
the  tool.  The  turn-bench  itself  is  "held 
steady  in  a  vice  fixed  to  a  bench  or  stand. 

The  common  lathe  of  the  turners  in 
wood,  called  the  pole-lathe,  is  the  same 
thing  as  the  watchmaker's  turn-bench, 
but  upon  a  large  scale,  and  a  little  varied. 
Instead  of  the  horizontal  bar,  it  has  two 
long  stout  bars  of  wood,  called  shears, 
forming  what  it  called  the  bed  of  the 
lathe,  and  its  two  poppet-heads  are  up- 
right blocks  of  wood,  mortised  in  be- 
tween the  shears,  above  which  they  rise 
and  carry  the  centre-screws,  and  be- 
tween which  they  are  movable,  and  may 
be  wedged  firmly  at  any  required  dis- 
tance from  each  other.  The  work  itself 
is  either  put  between  the  centres,  or  up- 
on a  wooden  mandrel,  and  is  made  to 
revolve  by  a  string  or  band,  proceeding 
from  a  long  spinning  pole  at  the  ceiling 
or  roof  of  the  shop,  round  the  work,  and 
thence  to  a  treddlo  or  foot-board,  which 
acts  by  alternate  pressure  from  the  foot, 
while  the  workman  applies  the  cutting 
tool  with  his  hands. 

The  velocity  of  rotation  may  be  ex- 
tremely swift  in  wood,  slower  in  brass 
and  bell-metal,  still  slower  in  cast-iron, 
and  slowest  of  all  in  forged  iron  or  steel. 
Steel  and  iron  require  to  be  kept  wet. 

If  the  poppet-heads,  supporting  the 
mandrel,  be  made  regularly  to  move  from 
side  to  side,  during  the  rotation,  or  the 
rest  be  made  to  approach  to,  and  recede 
from,  the  work,  any  number  of  times  in 
a  turn,  the  cuts  will  not  be  circular,  but 
undulating,  indented,  or  waved  in  any 
curve  that  may  be  required.  The  mo- 
tion is  commonly  regulated  by  certain 
round  plates  of  brass  fixed  on  the  man- 
drel, called  roves,  which  have  their  edges 
waved,  and  are  called  roses.  The  largest 
columns,  the  most  ponderous  artillery, 
and  the  minutest  pivots  of  watch- work, 
with  all  wheel-work,  rotatory  machines, 
vessels,  &c,  are  worked  by  this  ma- 
chine. 

Turning  of  earthemvare  and  porcelain 
is  requisite,  to  give  to  circular  vessels 


654 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tub 


their  correct  figure,  and  proper  size  and 
thickness.  The  lathe  has  similar  arrange- 
ment to  that  for  turning  wooden-vessels, 
&c. ;  with  this  addition,  the  treddle  has 
a  cross-piece,  for  convenience  of  a  tread- 
er,  giving  motion  more  readily  to  the 
wheel  and  spindle,  and  of  properly  re- 
gulating that  motion,  while  the  turner 
is  steadily  engaged  in  his  operations. 
Outside  of  the  head-stock  of  the  lathe, 
on  the  screw,  is  fixed  a  chuck,  of  the  size 
proper  for  the  inner  surface  of  the  edge 
of  the  vessel,  to  fit  easily.  The  turner 
stands  looking  towards  the  headstock 
(not  exactly  linear  with  his  lathe,  as  does 
the  wood-turner),  and  is  separated  from 
the  wheel  by  a  wainscot  partition,  so  as 
to  prevent  any  of  the  clay-turnings  fall- 
ing on  the  machinery.  The  treader 
stands  at  the  end  of  the  spindle,  on  a 
raised  position,  so  that  the  foot  requires 
the  treading,  to  give  force  to  the  treddle. 
At  the  side  of  the  treader  is  a  board,  on 
which  are  the  vessels  from  the  thrower, 
one  of  which  is  constantly  handed  over 
to  the  turner  as  he  needs  it. 

The  turner  places  the  vessel  on  the 
chuck,  and,  with  his  finger,  presses  its 
e^re  firm,  or  fixed  to  the  clay-ring  pre- 
viously formed  on  it,  the  treader  gives 
motion  to  the  spindle,  and  the  turner, 
by  his  tools  of  very  thin  steel,  varying  in 
breadth  for  the  several  vessels,  carefully 
abstracts  all  the  surplus  clay  left  by  the 
thrower,  and  likewise  add3  all  the  ele- 
gance the  pattern  suggests ;  and,  after 
this  is  finished,  the  treader  expertly  gives 
to  the  spindle  a  retrograde  motion,  dur- 
ing which  the  turner  "applies  the  flat  sur- 
face of  his  tool  to  the  vessel,  and  thereby 
gives  the  whole  a  solidity  not  previously 
existing,  and  also  a  glossy  smoothness, 
preventive  of  any  inequalities  the  prior 
operation  might  have  left.  It  will  be 
readily  conjectured,  that  this  manipula- 
tion affords  much  opportunity  for  exer- 
cising taste  and  genius,  and  requires  con- 
siderable practice,  to  prevent  the  articles 
being  fractured  and  destroyed. 

In  manufactories,  where  the  lathes 
have  motion  from  a  steam-engine,  the 
lathes  are  so  constructed  as  to  receive 
increased  velocity  for  those  parts  of  the 
operation  which  require  it.  There  is  a 
general  spur,  or  driving-shaft,  along  the 
room,  nigh  the  wall,  and  a  drum  fixed 
on  it,  over  each  lathe,  over  which  a  belt 
passes.  The  lathe  has  a  small  shaft  fixed 
parallel  to  its  spindle,  with  one  fixed  and 
two  loose  pulleys  ;  from  the  drum,  the 
belt  passes  round  the  fixed  pulley,  which 
will  give  motion  to  either  of  those  loose 


that  may  be  geared  with  it.  One  of  these 
gives  the  direct  motion  to  the  spindle, 
and  the  other,  to  the  crossed  belt,  gives 
the  retrograde. 

Some  articles,  after  being  taken  off  the 
turner's  lathe,  are  only  required  to  be 
gradually  dried,  to  be  ready  for  being 
baked  in  the  biscuit-oven ;  others  require 
to  be  ornamented,  figured,  or  hurdled,  and 
are  placed  where  they  will  not  dry 
quickly. 

Many  articles  of  a  circular  figure,  and 
some  hollow-ware,  of  even  oval,  are  form- 
ed and  finished  on  a  mould,  placed  on 
the  head  of  a  vertical  spindle,  moved  by 
a  winch  (not  dissimilar  to  a  lapidary's 
wheel),  and  a  larger  of  clay  (butted,  as 
described  under  pressing),  is  laid  on  the 
mould,  and,  by  swage  and  sponge,  as 
the  spindle  revolves,  has  the  full  thick- 
ness and  shape,  at  the  same  operation, 
completed.  This  is  much  used  to  fabri- 
cate saucers  and  plates. 

TURPENTINE  is  the  substance  which 
flows  from  incisions  made  in  the  stem  of 
the  pine  species.  It  has  the  consistence 
and  color  of  honey,  a  peculiar  smell,  a 
warm  and  bitter  taste ;  it  dries  in  the 
air :  it  melts  at  a  gentle  heat,  and  burns 
when  ignited  with  a  bright  sooty  flame. 
There  are  several  varieties,  as — 1.  Com- 
mon turpentine,  obtained  from  pinus  abies 
and  silvestris  :  it  consists  of  spirits  of  tur- 
pentine (volatile  oil),  from  5  to  26  per 
cent. ;  and  of  resin  or  colophony. — 2. 
Venice  turpentine,  is  extracted:  from  the 
pinus  larix  (larch),  and  the  French  tur- 
pentine from  the  pinus  maritama.  The 
first  comes  from  Styria,  Hungary,  the 
Tyrol,  and  Switzerland,  and  contains 
from  18  to  25  per  cent,  of  oil ;  the  se- 
cond, from  the  south  of  France,  and 
contains  no  more  than  12  per  cent,  of 
oil.  The  oil  of  all  the  turpentines  is  ex- 
tracted by  distilling  them  along  with  wa- 
ter. They  dissolve  in  all  proportions  in 
alcohol,  without  leaving  any  residuum. 
They  also  combine  with  alkaline  leys, 
and  in  general  with  the  salifiable  bases. 
Venice  turpentine  contains  also  succinic 
acid. — 3.  Turpentine  of  Strasbourg  is 
extracted  from  the  pinus  picea  and  ahie* 
excelsa.  It  affords  33-5  per  cent,  of  vo- 
latile oil,  and  some  volatile  or  crystal- 
lizable  resin,  with  extractive  matter  and 
succinic  acid. — 4.  Turpentine  of  the  Car- 
pathian mountains,  and  of  Hungary; 
the  first  of  which  comes  from  the  pinus 
cembra,  and  the  second  from  the  pinus 
mugos.  They  resemble  that  of  Stras- 
bourg.— 5.  Turpentine  of  Canada,  called 
|  Canad  a  balsam,   is  extracted   from  the 


TTP] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


655 


firms  canadensis  and  balsamea.  Its  smell 
xs  much  more  agreeable  than  that  of  the 
preceding  species. — 6.  Turpentine  of 
Cyprus  or  Ohio,  is  extracted  from  the 
pistacea  terebinthus.  It  has  a  yellow, 
greenish,  or  blue-green  color.  Its  smell 
is  more  agreeable,  and  taste  less  acrid, 
than  those  of  the  preceding  sorts. 

The  pine  forests  of  Carolina  and  Flo- 
rida supply  this  country  with  all  its  tur- 
pentine.   The  export  trade  is  considera- 

TUKPENTINE,  OIL  OF,  sometimes 
called  essence  of  turpentine.  As  found 
in  commerce,  it  contains  more  or  less  ro- 
sin, from  which  it  may  be  freed  by  re- 
distillation along  with  water.  It  is  color- 
less, limpid,  very  fluid,  and  possessed  of 
a  very  peculiar  smell.  Its  specific  gravity 
when  pure,  is  0-870.  It  always  reddens 
litmus  paper,  from  containing  a  little 
succinic  acid.  According  to  Opper- 
mann,  the  oil  which  has  been  repeatedly 
rectified  over  chloride  of  calcium,  con- 
sists of  84-60  carbon,  11-735  hydrogen, 
and  3-67  oxygen.  When  oil  of  turpen- 
tine contains  a  little  alcohol,  it  burns 
with  a  clear  flame ;  but  otherwise  it 
affords  a  very  smoky  flame.  Chlorine 
inflames  this  oil ;  and  muriatic  acid  con- 
verts it  into  a  crystalline  substance,  like 
camphor.  It  is  employed  extensively  in 
varnishes,  paints,  &c,  as  also  in  medi- 
cine. 

The  spirit,  or  oil  of  turpentine,  is  ob- 
tained from  the  crude  article  by  distilla- 
tion. When  the  volatile  oil  comes  over, 
and  colophony  is  lefc  behind  in  the  re- 
tort ;  250  lbs.  of  turpentine  yield  60  lbs.  of 
oil. 

A  patent  was  granted  in  1847,  for  re- 
fining turpentine  for  the  production  of 
the  pine  oil,  as  it  is  termed,  for  burning 
in  lamps.  The  resinous  matter  is  sepa- 
rated by  treating  the  turpentine  with 
potassa,  and  in  order  to  effect  thorough 
admixture  the  liquid  is  forced  through  a 
succession  of  fine  strainers.  After  this 
operation,  rain-water  is  added,  and  the 
whole  suffered  to  stand  for  twelve  hours, 
when  the  pure  spirits  will  be  found  float- 
ing above  the  water  and  impurities,  from 
which  it  is  drawn  off. 

A  patent  has  been  granted  for  an  im- 
provement in  the  distillation  of  crude 
turpentine,  consisting  merely  of  an  agi- 
tator or  stirring  apparatus,  working  with- 
out the  still,  the  shaft  of  the  agitator 
passing  through  a  stuffing  box  in  the  top 
of  the  still. 

The  stirring  of  various  liquids  in  the 
operation  of  boiling  is  a  common  device, 


but  has  never  been  before  applied  in  the 
production  of  turpentine,  and  is  in  this 
case,  as  asserted,  attended  with  consider- 
able advantages.  Turpentine  consists  of 
two  liquids,  one  boiling  at  a  much  high- 
er temperature  than  the  other,  which  is 
obvious  from  the  very  interesting  fact, 
that  while  boiling  without  pressure  its 
temperature  may  be  raised  more  than 
200°. 

Mr.  Viclette  has  adopted  the  process  of 
distillation  with  steam,  which  ne  found 
so  successful  in  the  case  of  quicksilver  {see 
Mercury),  to  the  treatment  of  turpentine 
with  great  economy  of  time  and  fuel,  and 
obtains  a  purer  article.  It  is  asserted 
that  in  this  country  Mr.  Wade  distilled 
turpentine  with  steam  so  long  as  three 
years  back. 

TYMPANUM,  in  architecture,  the 
space  in  a  pediment  enclosed  by  the  cor- 
nice of  the  inclined  sides,  and  the  hori- 
zontal fillet  of  the  corona. 

TYPES.  By  this  term  is  understood 
the  letters,  from  the  smallest  size  to  the 
largest,  with  which  books  and  other  arti- 
cles are  printed.  A  single  type  consists 
of  the  shank,  the  beard,  and  the  face. 
The  shank  is  the  body  of  the  letter ;  the 
beard  is  that  part  between  the  shoulder 
of  the  shank  and  the  face ;  the  face  is 
the  shape  of  the  letter,  from  which  the 
impression  is  taken. 

The  first  care  of  the  letter-cutter  is  to 
prepare  well-tempered  steel  punches,  up- 
on which  he  draws  or  marks  the  exact 
shape  of  the  letter,  with  pen  and  ink  if 
it  be  large,  but  with  a  smooth  blunted 
point  of  a  needle  if  it  be  small ;  and  then, 
with  a  proper  sized  and  shaped  graver 
and  sculptor,  he  digs  or  scoops  out  the 
metal  between  the  strokes  upon  the  face 
of  the  punch,  leaving  the  marks  un- 
touched and  prominent.  He  next  works 
the  outside  with  files  till  it  be  fit  for  the 
matrix.  Punches  are  also  made  by  ham- 
mering down  the  hollows,  filing  up  the 
edges,  and  then  hardening  the  soft  steel. 
Before  he  proceeds  to  sink  and  justify 
the  matrix,  he  provides  a  mould  to  justi- 
fy them  by. 

A  matrix  is  a  piece  of  brass  or  copper, 
about  an  inch  and  a  half  long,  and  thick 
in  proportion  to  the  size  of  the  letter 
which  it  is  to  contain.  In  this  metal  the 
face  of  the  letter  intended  to  be  cast  is 
sunk,  by  striking  it  with  the  punch  to  a 
depth  of  about  one-eighth  of  an  inch. 
The  mould  in  which  the  types  are  cast, 
is  composed  of  two  parts.  The  outer 
part  is  made  of  wood,  the  inner  of  steel. 
At  the  top  it  has  a  hopper-mouth,  into 


656 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[ULT 


which  the  fused  type-metal  is  poured. 
The  interior  cavity  is  as  uniform  as  if  it 
had  been  hollowed  out  of  a  single  piece 
of  steel.  From  the  pot,  over  the  furnace, 
containing  the  type  metal  fused,  a  small 
iron  ladle  lifts  as  much  as  will  cast  a  let- 
ter. The  metal  is  poured  into  the  ma- 
trix, and  with  a  jerk  of  the  hand  the  me- 
tal is  carried  round  the  matrix,  and  made 
to  till  all  its  crevices  perfectly.  A  tail  of 
metal  hangs  to  the  type  as  it  quits  the 
mould.  There  are  nicks  on  the  lower 
edge  of  the  type,  to  enable  the  composi- 
tor to  set  them  upright  without  looking 
at  them. 

The  tails  are  next  removed,  and  the 
broad  sides  of  the  type  rubbed  on  a  grit- 
stone. They  are  then  set  up  in  a  frame 
with  the  nicks  outward,  when  they  are 
polished  on  each  side  and  groved  at  the 
bottom,  to  make  them  stand  more  readi- 
ly. They  are  then  tied  up  in  lines  of 
suitable  length. 

Machines  for  type-making  are  com- 
mencing to  be  used,  and,  instead  of  a 
fused  metal  being  used,  a  rod  of  copper 
or  other  metal  is  pressed  by  machinery 
on  a  steel  die  having  the  letter  cut  into  it. 

TYPE  METAL.  The  alloy  of  lead 
and  antimony  used  in  casting*  printers' 
types.  One  part  of  antimony  to  three  of 
lead  are  the  usual  proportions.  This 
alloy  takes  a  sharp  impression  from  the 
the  mould  or  matrix,  and  is  hard  enough 
to  stand  the  work  of  the  press,  without 
being  brittle  or  liable  to  fracture. 

Besides  the  above  proportion,  the  fol- 
lowing is  often  followed  : — Put  into  a 
crucible  10  lbs  of  lead,  and  when  it  is  in 
a  state  of  fusion,  throw  in  2  lbs  of  anti- 
mony ;  these  metals  in  such  proportions 
form  the  alloy  of  which  some  printing 
types  are  made.  The  antimony  gives  a 
hardness  to  the  lead,  without  which  the 
type  would  be  speedily  rendered  useless  by 
the  printing  press.  Different  proportions 
of  lead,  copper,  brass,  and  antimony,  fre- 
quently constitute  this  metal.  Every 
artist  has  his  own  proportions,  so  that 
the  same  composition  cannot  be  obtained 
from  different  foundries. 

ULTRAMAEINE  is  a  beautiful  blue 
pigment  obtained  from  the  variegated 
blue  mineral,  called  lazulite  {lapis  lazuli), 
by  the  following  process: — Grind  the 
stone  to  fragments,  rejecting  all  the  co- 
lorless bits,  calcine  at  a  red  heat,  quench 
in  water,  and  then  grind  to  an  impalpa- 
ble powder  along  with  water,  in  a  paint- 
mill,  or  with  a  porphyry  slab  and  muller. 
The  paste,  being  dried,  is  to  be  rubbed 
to  powder,   and  passed  through  a  silk 


sieve.  100  parts  of  it  are  to  be  mixed 
with  40  of  rosin,  20  of  white  wax,  25  of 
linseed  oil,  and  15  of  Burgundy  pitch, 
previously  melted  together.  This  resin- 
ous compound  is  to  be  poured  hot  into 
cold  water ;  kneaded  well  first  with  two 
spatulas,  then  with  the  hands,  and  then 
formed  into  one  or  more  small  rolls. 
MM.  Clement  and  Desormes,  who  were 
the  first  to  divine  the  true  nature  of  this 
pigment,  think  that  the  soda  contained 
in  the  lazulite,  uniting  with  the  oil  and 
the  rosin,  forms  a  species  of  soap,  which 
serves  to  wash  out  the  coloring-matter. 
If  it  should  not  separate  readily,  water 
heated  to  about  150°  F,  should  be  had 
recourse  to.  When  the  water  is  suffi- 
ciently charged  with  blue  color,  it  is 
poured  off  and  replaced  by  fresh  water ; 
and  the  kneading  and  change  of  water 
are  repeated  till  the  whole  of  the  color  is 
extracted.  The  first  waters  afford,  by 
rest,  a  deposite  of  the  finest  ultramarine; 
the  second,  a  somewhat  inferior  article, 
and  so  on.  Each  must  be  washed  after- 
wards with  several  more  waters,  before 
they  acquire  the  highest  quality  of  tone  ; 
then  dried  separately,  and  freed  from  any 
adhering  particles  of  the  pitchy  com- 
pound by  digestion  in  alcohol.  The  best 
ultramarine  is  a  splendid  blue  pigment, 
which  works  well  with  oil,  and  is  not 
liable  to  change  by  time.  Its  price  in 
Italy  was  26  dollars  the  ounce,  a  few 
years  ago,  but  it  is  now  greatly  reduced. 

The  blue  color  of  kizidite  had  been  al- 
ways ascribed  to  iron,  till  MM.  Clement 
and  Desormes,  by  a  most  careful  analy- 
sis, showed  it  to  consist  of— silica,  34 ; 
alumina,  33 ;  sulphur,  3 ;  soda,  22 ;  and 
that  the  iron,  carbonate  of  lime,  &c, 
were  accidental  ingredients,  essential 
neither  to  the  mineral,  nor  to  the  pig- 
ment made  from  it.  By  another  analyst, 
the  constituents  are  said  to  be — silica,  44; 
alumina,  35;  and  soda,  21  ;  and  by  a 
third,  potassa  was  found  instead  of  soda, 
showing  shades  of  difference  in  the  com- 
position of  the  stone. 

Till  a  few  years  ago,  every  attempt 
failed  to  make  ultramarine  artificially. 
At  length,  in  1S28,  M.  Guimct  resolved 
the  problem,  guided  by  the  analysis  of 
MM.  Clement  and  Desormes,  and  by  an 
observation  of  M.  Tas^aert,  that  a  blue 
substance  like  ultramarine  was  ocasion- 
ally  produced  on  the  sandstone  hearths 
of  his  reverberatory  soda  furnaces.  M. 
Guimet  has  kept  his  process  secret.  M. 
Gmelin  of  Tubingen,  has  published  a 
prescription  for  making  it;  which  con- 
sists in  enclosing  carefully  in  a  Hessian 


val] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


657 


crucible  a  mixture  of  two  parts  of  sul- 

Ehur,  and  one  of  dry  carbonate  of  soda, 
eating  them  to  redness  till  the  mass 
fuses,  and  tben  sprinkling  into  it  by  de- 

§rees  another  mixture,  of  silicate  of  so- 
a,  and  aluminate  of  soda;  the  first  con- 
taining seventy-two  parts  of  silica,  and 
the  second  seventy  parts  of  alumina. 
The  crucible  must  be  exposed  after  this 
for  an  hour  to  the  fire.  The  ultrama- 
rine will  be  formed  by  this  time;  only 
it  contains  a  little  sulphur,  which  can  be 
separated  by  means  of  water.  M.  Fer- 
soz,  professor  of  chemistry  at  Stras- 
bourg, has  likewise  succeeded  in  mak- 
ing an  ultramarine.  Lastly,  M.  Robi- 
quet  has  announced,  that  it  is  easy  to 
form  ultramarine,  by  heating  to  redness 
a  proper  mixture  of  kaolin  (China  clay), 
sulphur,  and  carbonate  of  soda. 

UMBER  is  a  massive  mineral ;  frac- 
ture larpe  and  flat ;  conchoidal  in  the 
great,  very  fine  earthy  in  the  small ;  dull ; 
color,  liver,  chesnut,  or  dark  yellowish 
brown ;  opaque ;  does  not  soil,  but 
writes ;  adheres  strongly  to  the  tongue, 
feels  a  little  rough  and  meagre,  and  is 
very  soft ;  spec.  grav.  2-2.  It  occurs  in 
beds  with  brown  jasper  in  the  Island  of 
Cyprus,  and  is  used  by  painters  as  a 
brown  color,  and  to  make  varnish  dry 
quickly. 
UNIVERSAL  JOINT,  or  HOOKE'S 
JOINT.  In  machin- 
ery, an  ingenious  con- 
trivance of  Dr.  Hooke 
for  the  purpose  of 
communicating  mo- 
tion obliquely.  It  is 
single  or  double. 

URANIUM.  A  metal  discovered  by 
Klaproth  in  1789,  who  named  it  after  the 
planet  Uranus,  discovered  about  that 
time.  It  occurs  only  in  two  native  com- 
binations— the  fechhlende  of  Saxony,  and 
the  xiranite ;  of  the  latter,  fine  speci- 
mens have  been  found  in  Cornwall. 
Little  is  known  of  the  properties  of  me- 
tallic uranium  :  it  appears  to  be  a  brittle 
pray  metal,  of  the  spec.  grav.  of  about  9. 
From  the  experiments  of  Berzelius  and 
Arfwedson  we  deduce  the  number  217 
for  its  equivalent;  that  of  its  protoxide 
being  225,  and  of  its  peroxide  (ses- 
quioxide)  229.  The  salts  of  the  oxides 
of  uranium  are  of  a  fine  grass  green  or 
yellow  color :  the  persalts  have  been 
most  examined.  Ferrocyanate  of  pot- 
assa  produces  in  them  a  very  character- 
istic rich  brown  precipitate,  not  unlike 
that  formed  by  the  persalts  of  copper. 
*  28* 


They  are  also  precipitated  brown  by  in- 
fusion of  galls. 

UREA.  A  peculiar  crystallizable  sub- 
stance held  in  solution  in  the  urine. 
When  dried  in  vacuo  it  consists,  accord- 
ing to  Dr.  Front,  of— 


Atoms. 

Equiv. 

Theory,  i  Experiment. 

Nitrogen . . . 
Carbon  .... 
Hydrogen.. 
Oxygen.... 

2 

2 

1 
4 

28 
12 
4 
16 

46-67 
20-00 
6-67 
26-66 

46-65 

20  07 

6-65 

26-63 

1 

60 

100-00 

10000 

Urea  is  readily  soluble  in  water,  tasteless, 
inodorous  ;  and  when  mixed  with  the 
other  contents  of  the  urine  very  prone  to 
putrefaction,  the  principal  result  of  which 
is  carbonate  of  ammonia.  Urea  has  been 
artificially  obtained  by  the  action  of  am- 
monia on  cyanate  of  lead ;  oxide  of  lead 
is  precipitated,  and  colorless  crystals  of 
urea  obtained  by  carefully  evaporating 
the  solution. 

URIC  ACID.  Found  abundantly  in 
the  excrement  of  serpents  and  in  guano. 
In  the  latter  it  exists  often  to  the  amount 
of  40  per  cent,  as  urate  of  ammonia,  and 
free  uric  acid.  It  is  by  decomposition 
broken  up,  first  into  oxalate,  and  then 
into  carbonate  of  ammonia.  It  consists 
of  Cio  H4  N4  Og. 

VALONIA.  A  kind  of  acorn,  im- 
ported from  the  Levant  and  the  Morea 
for  the  use  of  tanners,  as  the  husk  or  cup 
contains  abundance  of  tannin. 

VALVE.  In  mechanics,  a  close  lid 
affixed  to  a  tube,  or  hollow  piston,  or 
opening  in  a  vessel,  by  means  of  a  hinge 
or  other  sort  of  movable  joint,  in  such 
a  manner  that  it  can  be  opened  only  in 
one  direction.  For  the  passage  of  Avater, 
the  clack-valve,  made  of  leather  and 
wood,  is  generally  used,  working  on  a 
side-axle,  or  a  central-axle,  or  pyramidi- 
cal.  A  steam-valve  is  a  flat  metal  plate, 
bevelled  at  the  edges  and  guided  by  a 
pin,  as  an  axis.  In  air-pumps  they  are 
of  oiled  silk,  with  a  prating.  But,  for 
every  purpose,  caoutchouc  is  the  best 
material.  In  the  great  London  works, 
valves  are  as  much  as  30  inches  in  dia- 
meter ;  and  the  great  column  of  water 
makes  them  act  with  astonishing  force. 
A  spherical  ball  of  metal  laid  on  the  end 
of  a  tube  properly  formed,  and  retained 
in  its  place  by  its  weight  alone,  is  some- 
times used  advantageously  instead  of  a 
valve,  as  in  the  hydraulic  ram.  The  safety 
valve  of  the  steam  engine  is  a  valve  at- 
tached to  the  boiler,  to  obviate  the  dan- 


658 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[van 


ger  of  its  bursting  in  case  the  steam 
should  become  too  strong.  The  valve  is 
so  loaded  that  its  weight,  added  to  that 
of  the  atmosphere,  exceeds  the  pressure 
of  the  steam,  when  of  a  sufficient  force. 
When  the  expansive  force  increases  so 
far  that  its  pressure  preponderates  over 
the  pressure  of  the  atmosphere  and  the 
weight  of  the  safety  valve,  the  valve 
opens,  and  the  steam  escapes  from  the 
boiler  till  its  elastic  force  is  sufficiently 
diminished,  and  the  valve  shuts  by  its 
own  weight.  By  opening  the  safety  valve 
the  engine  may  be  stopped  at  plcasu-e, 
for  which  purpose  a  particular  apparatus 
is  attached  to  the  valve.  As  any  acciden- 
tal derangement  of  the  safety  valve  might 
be  attended  with  the  most  disastrous  con- 
sequences, it  has  been  proposed  to  make 
the  valve  of  a  metal  which  melts  at  a  par- 
ticular temperature,  by  which  means  the 
elastic  force  of  the  steam  could  never  ex- 
ceed that  which  corresponds  to  the  tem- 
perature at  which  the  valve  would  melt. 
This  method  has  been  adopted  in 
France. 


Dwplex  Safety  Valve.  This  valve  is  the 
invention  of  Mr.  S.  A.  Williams,  of  Corn- 
wall, England.  Its  object  is  to  prevent  the 
ordinary  valve  from  adhering  to  its  seat, 
when,  from  any  cause,  the  internal  pres- 
sure falls  below  the  atmospheric  pressure, 
and  also  to  indicate  the  quantity  of  water 
in  the  boiler,  to  prevent  it  from  getting 
too  low.  The  common  safety  valve  opens 
in  the  usual  way,  and  is  linked  to  a 
weighted  lever  d,  g.  The  weighted  lever 
is  extended  to  the  other  side,  beyond  the 
fulcrum,  to  a  distance  equal  to  that  of 
its  distance  from  the  valve.  There  is  a 
small  valve  linked  to  this  opposite  end  of 
the  lever.  It  is  placed  inside  of  the  man- 
hole lid,  opening  downwards.  Any  up- 
ward movement  of  the  valve  produces 
a  corresponding  downward  movement  of 
the  smaller  valve.  The  internal  pressure 
tending  to  open  the  valves,  will  be  ex- 
erted only  on  the  excess  of  the  area  of 
the  larger  valve  over  the  area  of  the 
smaller  one.  A  chain  is  connected  to  a 
float  and  the  small  valve.  When  the 
float  is  kept  up  by  the  water,  the  chain 
is  loose,  but  when  the  water  falls  below 


the  proper  limit,  the  small  valve  is  drawn 
down,  and  the  other  valve  up,  thus 
blowing  off  at  once  a  great  deal  or  steam. 
This  valve  is  somewhat  interesting  as 
being  a  very  neat  modification  of  the 
equilibrium  valve. 

Frequently  a  narrow  bar  of  metal  is 
made  fast  across  a  circular  orifice  in  the 
direction  of  the  diameter,  and  2  semicir- 
cular valves  of  leather,  each  of  which  is 
covered  above  and  below  with  a  brass 
plate  of  the  same  form,  turn  on  the  sides 
of  the  bar  as  on  hinges.  This  is  called 
the  double  check  or  butterfly  valve. 

When  instead  of  bars  of  metal  the  re- 
sistance of  the  valve  is  afforded  by  a 
spring,  this  is  the  spring  valve,  an  il- 
lustration of  which  is  given  here. 


VANADIUM.  A  metal  discovered  in 
1830,  by  Professor  Seftstrom  of  Fahlun, 
in  iron  prepared  from  the  iron  ore  of 
Taberg  in  Sweden.  Vanadium  has  also 
been  found  in  a  lead  ore  from  Wanlock- 
head  in  Scotland,  and  in  a  similar  mineral 
from  Zimapan  in  Mexico.  Vanadium  is 
a  white  brittle  metal,  very  difficult  of  re- 
duction ;  not  oxidized  by  air  or  water ; 
and  insoluble  in  sulphuric,  muriatic,  and 
hydrofluoric  acids  ;  but  soluble  in  nitric 
and  nitromuriatic  acids,  with  which  it 
yields  solutions  of  a  fine  dark  blue  color. 
It  is  not  acted  upon  by  boiling  caustic 
potash,  nor  bv  the  carbonated  alkalies  at 
a  red  heat.  The  peroxide  of  vanadium 
is  of  an  orange  color,  and  very  slightly 
soluble  in  water;  it  unites  with  the" sali- 
fiable bases;  with  the  alkalies  its  salts 
are  soluble,  with  the  other  bases  sparing- 
ly soluble.  These  salts  are  orange  or 
yellow  colored ;  in  these  and  other  res- 
pects there  is  a  close  resemblance  be- 
tween vanadium  and  chromium.  Perox- 
ide of  vanadium,  or  vanadic  acid,  is  dis. 
tinguished  from  chromic  acid  by  the  ac- 
tion of  deoxidizing  substances,  which 
give  a  blue  solution  with  vanadium,  but 
a    green  one  with  chromium.      When 


var] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


659 


heated  with  borax  in  the  reducing  flame 
of  the  blowpipe,  both  of  the  acids  yield 
a  green  glass ;  but  in  the  oxidizing  flame 
the  bead  becomes  yellow  if  vanadium  is 
present,  but  the  green  color  is,  perma- 
nent if  produced  by  chronium.  Accord- 
ing to  the  experiments  of  Berzelius,  the 
equivalent  of  vanadium  is  about  68;  and 
the  protoxide,  the  deutoxide,  and  the 
vanadic  acid,  are  composed  respectively 
">f  1  atom  of  vanadium,  and  1,  2,  and  3 
~>f  oxygen.  It  exists  in  the  copper  of 
Lake  Superior. 

VANL.  A  contrivance  for  showing 
the  direction  of  the  wind.  It  consists 
usually  of  a  thin  slip  of  wood  or  metal, 
attached  to  a  perpendicular  axis,  round 
which  it  moves  freely  ;  and  is  so  shaped 
that  it  presents  always  the  same  extremi- 
ty to  the  point  of  the  horizon  from  which 
the  wind  blows. 

VANILLA.  The  succulent  fruit  of  a 
plant  of  the  Orchidaceous  order,  climbing 
over  trees  in  the  tropical  parts  of  this  con- 
tinent after  the  manner  of  ivy.  Its  fra- 
grance is  owing  to  the  presence  of  ben- 
zoic acid,  crystals  of  which  form  upon 
the  pod  if  allowed  to  be  undisturbed.  It 
is  an  aromatic,  employed  in  confectionary 
and  the  preparation  of  liqueurs,  and  in 
flavoring  of  chocolate,  ice-cream,  &c. 

VARNISH.  A  fluid  which  when 
spread  thin  upon  a  solid  surface  becomes 
dry,  and  forms  a  coating  impervious  to 
air  and  moisture.  There  are  two  kinds 
of  varnish,  namely,  spirit  and  oil  var- 
nishes: rectified  alcohol  is  used  for  the 
former ;  and  for  the  latter  fixed  and  vo- 
latile oils,  or  mixtures  of  the  two.  The 
solid  substances  dissolved  in  the  above 
menstrua,  and  which  constitute  what  is 
termed  the  body  of  the  varnish,  are  al- 
most exclusively  resinous,  and  are  chiefly 
the  following:  1.  Turpentine,  all  the  va- 
rieties of  which  are  employed  by  the 
varnisher :  they  form  an  excellent  body, 
and  give  strength  and  glossiness  at  a 
small  expense  ;  but  they  do  not  dry  with- 
out other  additions.  2.  Copal,  a  peculiar 
resin,  very  difficult  to  dissolve,  but  form- 
ing a  hard  and  durable  ingredient.  It  is 
generally  melted  over  a  gentle  fire  pre- 
vious to  use.  3.  Lac,  which  gives  great 
toughness  and  hardness  ;  but  is  often  in- 
admissible, on  account  of  its  reddish- 
brown  color.  4.  Mastic,  which  yields  a 
tough,  hard,  brilliant,  and  colorless  var- 
nish. 5.  Elemi,  a  resin  of  a  pale  yellow 
green  tint,  and  a  valuable  ingredient  on 
account  of  its  toughness  and  durability. 
6.  Sandarach,  a  resin  which  imparts 
splendor,   but  which  alone  is  not  dura- 


ble. 7.  Amber,  a  valuable  ingredient,  on 
account  of  its  hardness  and  durability  • 
but  difficult  of  transparent  solution,  ana 
hence  chiefly  used  in  opaque  varnishes. 
8.  Benzoin,  added  on  account  of  its  fra- 
grancy.  9.  Anirne,  which  gives  brillian- 
cy and  some  scent.  10.  Gamboge,  for 
yellow  varnishes.  11.  Dragon's  blood,  for 
red  varnish.  These,  together  with  tur- 
meric, saffron,  and  annotta,  are  chiefly 
used  on  account  of  their  color,  aud  to 
cover  brass  and  copper  under  the  name 
of  lacquers.  12.  Caoutchouc.  This  extra- 
ordinary vegetable  product  has  of  late 
been  much  employed  in  a  variety  of  pre- 
parations used  as  varnishes.  It  is  invalu- 
able where  materials  are  to  be  rendered 
air-tight,  as  balloons,  for  example,  and 
where  at  the  same  time  flexibility,  and 
even  elasticity,  are  required;  but  its 
principal  application  in  this  way  is  in  the 
manufacture  of  various  water-proof  arti- 
cles. 13.  Asphaltum,  the  varieties  of 
which  are  indispensable  in  black  oil  var- 
nishes. In  making  spirit  varnishes,  the 
strongest  alcohol  of  commerce  should 
be  used  (of  a  specific  gravity  not  ex- 
ceeding 820),  and  its  solvent  power  over 
some  of  the  more  intractable  resins  is 
sometimes  improved  by  the  addition  of 
a  little  camphor;  in  order  to  prevent  the 
agglutination  of  the  resin,  it  is  often  re- 
quisite to  mix  it  with  sand  or  pounded 
glass,  by  which  the  surface  is  much  in- 
creased, and  the  solvent  energy  of  the 
spirit  facilitated.  The  proportions  in 
which  the  several  ingredients  are  used, 
and  the  selections  for  particular  purposes, 
are  infinitely  various.  The  following  are 
a  few  good  varnishes,  in  illustration  of 
their  varieties  :  1.  Spirit  varnish.  San- 
darach 4  oz.,  seed  lac  2  oz.,  elemi  1  oz., 
digest  the  whole  in  a  quart  of  moderately 
warm  alcohol,  and  wnen  dissolved  add 
Venice  turpentine,  2  ozs.  2.  Lac  varnish. 
Seed  lac  8  oz. ;  digest  for  four  days  in  a 
warm  place  with  a  quart  of  alcohol,  and 
then  strain  through  flannel.  3.  Turpen- 
tine varnish.  Mastic  12  oz.,  mixed  with 
5  oz.  of  pounded  glass,  and  digested  in  a 
quart  of  oil  of  turpentine,  adding  at  in- 
tervals about  half  an  ounce  of  camphor 
in  small  pieces.  When  the  mastic  is 
dissolved,  add  to  the  warm  fluid  an  ounce 
and  a  half  of  previously  liquefied  Venice 
turpentine,  and  stir  the  whole  together. 
4.  Copal  varnish.  Copal  which  has  been 
previously  melted  by  a  gentle  heat  3  oz., 
oil  of  turpentine  20  oz.  (measure) :  put 
the  oil  into  a  flask  placed  in  boiling 
water,  and  add  the  powdered  copal  in 
small  portions  at  a  time,  so  that  it  may 


660 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[VAR 


be  gradually  dissolved ;  let  it  stand  a  few 
days  to  clear,  and  then  pour  it  off,  and  if 
too  thick  for  use,  add  to  it  a  little  warm 
oil  of  turpentine.  This  varnish  dries 
slowly,  but  is  very  durable.  5.  Linseed 
varnish.  Melt  16  oz.  of  copal  in  an  iron 
pot  with  as  gentle  a  fire  as  possible,  and 
when  fused  pour  in  3  oz.  of  hot  linseed 
oil ;  stir  the  mixture,  remove  it  from  the 
fire,  and  while  yet  warm  gradually  add  a 
pint  of  warm  oil  of  turpentine ;  when 
the  whole  is  incorporated,  strain  it 
through  a  pice  of  linen  into  phials.  Thi" 
is  a  hard  and  durable,  but  also  a  colored 
varnish.  6.  Amber  varnish.  Melt  16  oz. 
of  amber  in  an  iron  pot,  then  add  two 
oz.  of  melted  lac,  and  10  oz.  of  hot,  dry- 
ing linseed  oil ;  incorporate  the  whole  by 
stirring  ;  remove  it  from  the  fire,  and  be- 
fore it  cools  add  a  pint  of  warm  oil  of 
turpentine.  7.  Black  varnish.  Melt  16 
oz.  of  amber  in  an  iron  pot,  and  add  half 
a  pint  of  hot,  drying  linseed  oil,  3  oz.  of 
powdered  rosin,  and  3  oz.  of  powdered 
asphaltnm ;  stir  all  together,  and  when 
removed  from  the  fire  and  sufficiently 
cool,  add  a  pint  of  warm  oil  of  turpentine. 
8.  Lacquer.  Digest  3  oz.  of  seed  lac,  1 
oz,  of  turmeric,  and  2  drs.  of  dragon's 
blood  for  six  days  in  a  pint  of  alcohol, 
frequently  shaking  the  bottle,  which 
should  be  kept  in  a  warm  place ;  strain 
the  lacquer  through  linen.  The  above  are 
samples  of  each  of  the  principal  varnish- 
es ;  but  every  maker  varies  the  propor- 
tions, and  often  the  nature  of  the  ingre- 
dients. In  the  preparation  of  varnishes, 
in  consequence  of  the  highly  combusti- 
ble nature  of  all  the  materials,  the  utmost 
care  is  requisite  to  avoid  accidents  by  fire. 
White  Polishing  Varnish.  In  a  quart  of 
alcohol  mix  8  oz.  of  juniper  gum,  2  oz.  of 
mastic  in  tears,  1  oz.  of  gum  eleini,  and 
4  oz.  of  Strasburgh  turpentine,  For  metal, 
with  pumice-powder.  In  this  dissolve  1 
oz.  of  copal,  in  fine  powder,  and  filter. 
In  one  pint  of  alcohol  dissolve  1  oz.  of 
gum  elemi:  mix  the  two  liquids.  Or, 
(for  Pictures.)  In  one  pint  of  alcohol 
dissolve  i  oz.  of  camphor,  which  mix 
with  4  oz.  of  coarse  powder  of  copal,  and, 
by  heat,  form  the  mixture,  till  whatever 
bubbles  arise  may  easily  be  counted. 
Cool,  decant,  and  add  more  alcohol,  to  be 
similarly  treated,  till  there  is  no  residuum. 
Or  (for  Metals,  Chairs,  dbc.)  Mix  well  4 
oz.  of  powder  of  glass,  (or  potter's  flint,) 
2i  oz.  of  Strasburgh  turpentine,  3  oz.  of 
gum  mastic,  6  oz."  of  gum  sandarac,  and 
3  oz.  of  copal,  melted  and  dropped  into 
water,  Acid  the  whole  to  1  quart  of  al- 
cohol. 


Copal  Varnish  (Sheldrake'' s).  Take  of 
copal,  broken  into  small  pieces,  2  oz., 
spirit  of  ammonia  2  oz.,  or  camphor  2 
drs.,  rectified  oil  of  turpentine  1  pint. 
Stop  the  vessel,  with  a  cork  cut  in 
grooves,  to  admit  a  portion  of  the  heat- 
ed vapors  to  escape ;  bring  it  to  boil  over 
a  brislc  fire,  so  that  the  bubbles  may  be 
counted  as  they  rise  ;  keep  the  mixture 
at  the  same  heat ;  for,  if  the" least  irregu- 
larity, or  overheating,  takes  place,  it  is 
useless  to  proceed.  When  the  solution 
is  complete,  let  the  vessel  be  quite  cool 
before  it  is  opened.  The  vessel  is  of  tin, 
or  other  metal,  strong,  shaped  like  a  wine- 
bottle  with  a  long  neck,  and  capable  of 
holding  two  quarts. 

Copal  varnish  may  be  dissolved  on  pic- 
tures, &c.  by  a  boiling  solution  of  an 
eighth  of  ammonia,  in  oil  of  turpentine, 
but  it  requires  very  skilful  management. 

Japanner's  Copal  Varnish.  In  a  glass 
matrass  melt  and  evaporate  4  lbs  of  co- 

f>al,  and  pour  in  1  pint  of  boiling  hot 
inseed-oil ;  remove  the  matrass,  and, 
while  hot,  add  equal  weight  of  oil  of  tur- 
pentine. 

Gold  Varnish,  for  Leather.  In  2  pints 
of  oil  of  turpentine  mix  liscrs.  of  gam- 
boge and  turmeric  each,  4  oz.  each  of  seed 
lac  and  gum  sandarac,  i  oz.  of  dragon's 
blood,  2  oz.  of  turpentine,  and  4  oz.  of 
pounded  glass,  (or  potter's  flint) — use  the 
clear. 

Varnish  for  Colored  Drawings.  Mix 
1  oz.  of  Canada  balsam  and  2  oz.  of  oil  of 
turpentine.  Size  first  with  isinglass,  and 
dry  before  using  the  varnish. 

Indian  Varnish.  In  1  quart  of  alcohol, 
by  a  gentle  heat,  dissolve  5  oz.  of  shell 
lac  and  of  seed  lac.    Strain  for  use. 

Hard  Spirit  Varnish.  In  1  quart  of 
alcohol  dissolve  3  oz.  of  seed  lac  and  of 
yellow  rosin. 

Black  Varnish.  In  1  quart  of  alcohol 
dissolve  4  oz.  of  gum  sandarac,  and  2  oz. 
of  yellow  rosin  ;  then  add  one  oz.  of  lamp- 
black. Or,  alcohol  and  black  sealing- 
wax,  to  color  it. 

To  make  Caoutchouc  Varnish.  Melt 
the  caoutchouc  in  a  close  vessel,  at  near- 
ly the  temperature  to  melt  lead,  and  stii 
it.  Oil  of  turpentine  should  be  carefully 
added  to  it,  which  will  render  it  easily 
applicable,  and  leaves  the  substance,  when 
dry,  a  firm  varnish,  impermeable  to  mois- 
ture. It  is  an  excellent  varnish,  for  pre- 
serving iron  and  steel  from  rust ;  and  it 
may  be  removed  by  a  soft  brush,  dipped 
in  oil  of  turpentine.  A  solution  of  caout- 
chouc, in  five  times  its  weight  of  oil  of 
turpentine,  and  this  solution  mixed  with 


var] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


661 


eight  times  its  -weight  of  drying  linseed- 
oiT,  by  boiling,  forms  the  varnish  usually 
applied  to  air-balloons.  Or,  Digest  1  oz. 
of  caoutchouc,  cut  into  small  pieces,  in 
32  oz.  of  naphtha ;  and,  when  it  is  dissolv- 
ed, strain  the  varnish  through  a  linen 
cloth. 

Oil  of  Tar,  for  Common  Varnishes,  may 
be  employed  instead  of  naphtha. 

Varnish  for  Iron  or  Wood.  Dissolve  i 
pint  of  alcohol  in  a  gallon  of  wood  tar. 

Bed  Varnish,  (for  Cabinet-work  and 
Violins.)  In  1  quart  of  alcohol  dissolve 
2  oz.  of  Strasburgh  turpentine,  1  oz.  of 
mastic  and  of  choice  benjamin,  2  oz.  of 
seed  lac,  and  4  oz.  of  gum  sandarac.  Or, 
(for  Metals.)  In  1  quart  of  alcohol  dis- 
solve 6  oz.  of  Venice  turpentine,  4  oz.  of 
brown  rosin,  2  oz.  of  shell  lac,  and  8  oz. 
of  gum  sandarac. 

Sj>h'it  Varnish,  for  Colors  on  Wood. 
In  a  matrass,  capable  of  containing  two 
Paris  pints  of  liquid,  put  a  pint,  or  about 
2  lbs.,  of  good  spirit  of  wine,  and  throw 
in  4  oz.  of  shell  lac,  broken  into  small 
bits,  together  with  2  oz.  of  gum  sanda- 
rac, and  1  oz.  of  gum  mastic  in  tears, 
grossly  powdered  ;  you  also  add  1  oz.  of 
oil  of  spike,  and  place  the  vessel  upon  a 
ring  of  straw,  laid  upon  the  bottom  of  a 
boiler  filled  with  water ;  the  whole  must 
be  then  heated  in  a  furnace  over  a  char- 
coal fire,  and  the  contents  be  stirred  from 
time  to  time,  until  the  gums  are  entirely 
melted  ;  but  care  is  to  be  taken  that  the 
spirit  of  wine  be  not  heated  to  its  boil- 
ing-point. This  varnish,  when  cold,  is  fit 
to  mix  with  lamp-black,  vermilion,  or 
other  opaque  colors ;  but,  when  it  is  to 
be  used  alone,  to  give  a  fine  polish,  it 
should  be  filtered,  either  through  cotton 
or  filtering  paper. 

Varnish  for  out-door  Painting.  Boil 
half  a  gallon  of  linseed  oil  in  an  iron  pot, 
for  an  hour,  and  then  lay  in  it  a  round 
of  crum  of  bread,  to  absorb  the  fat,  and 
boil  some  time.  Take  out  the  bread,  and 
put  in  a  lb.  of  powdered  rosin  gradually, 
and  stir  with  an  iron  spatula.  Add  4  oz., 
or  more,  of  the  spirits  of  turpentine,  and 
strain  it.  It  bears  weather,  wear,  and 
hot  water.  The  same  may  also  be  made 
of  1  oil  of  turpentine  and  4  rosin,  well 
boi'ed.  Or,  by  boiling  16  drying  linseed- 
oil,  8  of  gum'  sandarac,  and  1  of  oil  of 
turpentine. 

It  is  usual,  in  the  manufacture  of  spirit 
varnishes,  to  mix  glass  or  sand  with  the 
resin,  for  the  purpose  of  affording  ready 
access  of  the  alcohol  to  all  parts  of  the 
solid  mass.  M.  Ferrari,  however,  recom- 
mends that,  in  place  of  these  substances, 


coarsely  powdered  charcoal  should  be 
used ;  for  the  glass  or  sand  frequently 
tends  to  aggregate  the  resin  at  the  bottom 
of  the  vessels  and  protect  it  from  the 
solvents,  whilst,  on  the  contrary,  the 
charcoal  rather  tends  to  raise  and  divide 
it.  The  most  advantageous  proportion 
appears  to  be  about  1  oz.  of  charcoal  to  1 
lb.  of  the  spirits  or  the  oil  of  turpentine. 

To  Varnish  Silk.  If  the  surface  of  the 
silk  be  pretty  large,  it  is  made  fast  in  a 
wooden  frame  furnished  with  hooks  and 
movable  pegs.  A  certain  quantity  of  a 
soft  paste,  composed  of  linseed-oil,  boil- 
ed with  a  fourth  part  of  litharge,  white 
of  Troyes,  Spanish  white  or  tobacco-pipe 
clay,  lamp-black  and  litharge,  is  then 
prepared,  in  nearly  the  following  propor- 
tions :  tobacco-pipe  clay,  dried  and  sifted 
through  a  silk  sieve,  16  parts  ;  litharge, 
ground  with  water,  dried  and  sifted  in 
the  same  manner,  3  parts  ;  lamp-black,  1 
part.  This  paste  is  then  spread  in  an 
uniform  manner  over  the  surface  of  the 
silk,  by  means  of  a  long  knife,  having  a 
handle  at  each  extremity. 

In  summer,  24  hours  are  sufficient  for 
drying,  and  when  dry,  the  knots  produ- 
ced by  the  inequalities  of  the  silk  are 
smoothed  with  pumice-stone.  This  ope- 
ration is  performed  with  water;  and, 
when  finished,  the  surface  of  the  silk 
is  washed.  It  is  then  suffered  to  dry,  and 
copal  varnish  applied. 

If  it  be  intended  to  polish  this  varnish, 
it  will  be  proper  to  apply  a  second  stra- 
tum; after  which  it  is  polished  with  a 
ball  of  cloth  and  very  fine  tripoli,  or  with 
a  piece  of  strong  cloth  only.  The  var- 
nished silk  which  results  from  this  pro- 
ces  is  very  black,  exceedingly  pliable,  and 
has  a  fine  polish.  It  may  be  rumpled 
any  way  without  retaining  any  fold,  or 
the  mark  of  a  fold. 

Varnished  silk,  which  has  a  yellowish 
color,  is  prepared  with  a  plain  varnish. 
The  silk  is  covered  with  a  mixture  of 
three  parts  of  boiled  oil  of  poppy,  and 
one  part  of  fat  copal  varnish,  which  is 
spread  with  a  coarse  brush,  or  with  a 
knife.  Two  coats  are  sufficient,  when 
the  oil  has  been  freed  from  its  greasy 

Erinciples  over  a  slow  fire,  or  when  it  has 
een  boiled  with   a  fourth  part   of  its 
weight  of  litharge. 

White  Varnish.  In  1  quart  of  alcohol 
mix  1  lb.  of  juniper  gum  and  6  oz.  of 
Strasburgh  turpentine.  For  wood,  linen, 
and  paper. 

White  Hard  Varnish.  Pulverize  8  oz. 
of  cullet  (Hint  glass,  or  use  3  oz.  of  pot- 
ter's  dried    flint) ;    mix    with   4  oz.    of 


662 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[YEN 


inastic,  and  2  oz.  of  juniper  gum  and 
of  Venice  turpentine,  which  put  into  1 
quart  of  alcohol.    For  cards,  sheaths,  &c. 

VARVICITE.  An  ore  of  manganese 
found  at  Hartshill  in  Warwickshire,  Eng. 
appears  to  be  a  compound  of  2  equiva- 
lent* of  peroxide  and  1  of  sesquioxide  of 
manganese  with  1  of  water. 

VEGETABLE  ALKALOIDS.  Under 
the  title  of  vegetable  alkaloids  are  com- 
prehended those  proximate  principles 
which  are  possessed  of  alkaline  properties. 
They  all  consist  of  carbon,  hydrogen,  oxy- 
gen, and  nitrogen,  and  they  are  decom- 
posed with  facility  by  nitric  acid,  and  by 
neat ;  and  ammonia  is  always  one  of  the 
products  of  the  destructive  distillation. 
As  they  agree  in  several  of  their  leading 
chemical  properties,  the  mode  of  prepar- 
ing them,  with  slight  variation,  is  general. 
The  substance  containing  the  alkaline 
principle  is  digested,  or,  more  commonly, 
macerated,  in  a  large  quantity  of  water, 
which  dissolves  the  salt,  the  base  of 
which  is  the  vegetable  alkali.  On  adding 
some  more  powerful  salifiable  base,  such 
as  potash  or  ammonia,  or  boiling  the  so- 
lution, for  a  few  moments,  with  lime  or 
pure  magnesia,  the  vegetable  alkali  is  se- 
parated from  its  acid ;  and,  being  in  that 
state  insoluble  in  water,  may  be  collected 
on  the  filter,  and  washed.  To  purify  it 
from  certain  oleaginous,  resinous  sub- 
stances, and  coloring  matters,  it  is  mix- 
ed with  a  little  animal  charcoal,  and  dis- 
solved in  boiling  alcohol.  This  solution  is 
filtered  while  hot,  and  evaporated  to  dry- 
ness, which  affords  the  alkali  in  a  state 
of  perfect  purity.  Upwards  of  twenty 
of  these  bodies  have  already  been  inves- 
tigated ;  as  morphia,  cinchonia,  quinia, 
strychnia,  brucia,  veratria,  and  sangui- 
naria. 

VELOCIPEDE.  A  vehicle  invented 
at  Mannheim  in  1817,  by  M.  Drais,  con- 
sisting of  a  piece  of  wood  about  five  feet 
long,  and  half  a  foot  wide,  resting  on 
two  wheels,  one  behind  the  other.  On 
this  an  individual  sits,  as  on  horseback, 
his  feet  touching  the  ground,  and  thus 
propelling  the  machine.  The  front  wheel 
may  be  turned  at  pleasure,  so  that  the 
rider  may  give  any  direction  to  the  ma- 
chine. This  species  of  vehicle  never  came 
into  general  use  ;  but  it  was  improved  by 
Knight  in  England,  and  a  patent  receiv- 
ed for  it. 

VELLUM.  A  fine  kind  of  parchment 
made  of  calf-skin.  The  skins  are  limed, 
shaved,  washed,  and  stretched  in  proper 
frames,  where  they  are  scraped  with  the 
currier's    fleshing-tool,    ana    ultimately 


rubbed  down  to  a  proper  thickness  with 
pumice. 

VELVET.  This  beautiful  substance  is 
mostly  a  silk  fabric,  remarkable  for  the 
softness  of  its  surface.  This  softness  is 
owing  to  a  loose  pile  or  surface  of  threads, 
occasioned  by  the  insertion  of  soft  pieces 
of  silk  thread  doubled  under  the  shoot, 
weft  or  cross  threads.  These  stand  up- 
right so  thickly  as  entirely  to  conceal  the 
interlacing  of  the  warp  and  shoot.  The 
richness  of  the  velvet  depends  upon  the 
closeness  of  the  pile-threads.  The  inser- 
tion of  these  short  threads  is  effected  in 
the  following  manner : 

Instead  of  having  only  one  row  of  warp 
threads,  which  will  be  crossed  alternately 
over  and  under  by  the  shoot,  there  are 
two  sets,  one  of  which  is  to  form  the 
regular  warp,  while  the  other  is  to  con- 
stitute the  pile,  and  these  two  sets  are  so 
arranged  in  the  loom  as  to  be  kept  sepa- 
rate. The  quantity  of  the  pile-thread 
necessary  is  very  much  more  than  that  of 
the  warp  thread,  and  therefore  must  be 
applied  to  the  loom  by  a  different  agency. 
If  the  pile-threads  were  worked  in  a- 
mong  the  shoot,  in  the  same  way  as  the 
warp-thread,  the  fabric  would  be  simply 
of  a  kind  of  double  silk,  but  without  any 
kind  of  pile ;  the  pile-threads  are  there- 
fore formed  into  a  series  of  loops,  stand- 
ing up  from  the  surface  of  the  silk  ;  and 
by  subsequently  cutting  these.loops  with 
a  sharp  instrument,  the  pile  is  produced. 
Thin  brass  wires  are  temporarily  woven 
in  among  the  weft-threads  to  asssist  in 
forming  the  loops  ;  and  by  a  delicate  cut 
or  scission  made  with  a  sharp  instrument, 
the  loops  are  cut  and  the  wires  liberated. 
Striped  velvets  are  produced  by  some  of 
the  pile-threads  being  uncut. 

VENICE  SOAP,  AND  MOTTLED 
CASTILE  SOAP,  are  merely  olive-oil 
and  soda,  with  a  little  sulphate  of  iron 
in  solution,  or  sulphate  of  zinc. 

VENTILATOR.  Any  machine  or  con- 
trivance for  promoting  or  regulating  ven- 
tilation. The  common  ventilator  placed 
in  windows,  which  revolves  in  the  same 
manner  as  a  smoke-jack,  in  consequence 
of  the  impulsion  of  a  current  of  air, 
serves  only  to  retard,  in  some  degree,  the 
entrance  of  the  current,  to  disperse  it  in 
different  directions,  and  to  prevent  any 
sudden  increase  in  the  intensity  of  the 
draught.  It  has  no  power  of  acting  so  as 
to  create  a  current,  or  keen  up  its  inten- 
sity when  it  has  been  established. 

VENTILATION.  This  word  liter- 
ally signifies  fanning  or  blowing.  In 
domestic  economy,  it  is  the  art  of  con- 


ri 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


663 


veying  currents  of  fresh  air  through 
close  apartments  or  confined  places,  so  as 
to  maintain  the  atmosphere  m  a  state  of 
purity. 

Atmospheric  air  consists  of  two  ingre- 
dients, oxygen  and  azote,  blended  toge- 
ther in  the  proportion  of  one  part  by 
measure  of  the  former  to  four  of  the  lat- 
ter. When  these  proportions  are  altered, 
air  becomes  unfit  to  respiration ;  and 
when  the  oxygen  is  withdrawn  or  con- 
sumed, it  is  rendered  altogether  incapa- 
ble of  supporting  animal  life  or  combus- 
tion. But  there  are  operations  both  of 
nature  and  art  continually  going  forward 
in  which  the  oxygen  of  the  atmosphere 
is  consumed,  and  gaseous  products  evolv- 
ed which  are  destructive  of  life.  Thus, 
in  the  act  of  respiration,  a  certain  portion 
of  the  oxygen  contained  in  the  air  inhal- 
ed into  the  lungs  is  converted  into  car- 
bonic acid,  a  substance  which  acts  as  a 
narcotic  poison  ;  and  hence,  in  a  confin- 
ed apartment,  air  is  soon  rendered,  by 
breathing  alone,  not  merely  incapable  of 
maintaining  life,  but  highly  destructive 
of  it,  in  consequence  of  the  evolution  of 
a  deleterious  gas.  In  like  manner,  oxy- 
gen is  consumed,  and  carbonic  acid 
evolved,  in  the  process  of  combustion  ; 
and  the  burning  of  a  pan  of  charcoal  in 
a  close  room  is  known  to  be  a  certain 
means  of  extinguishing  life. 

Although  a  decomposition  and  deteri- 
oration of  air  is  thus  continually  going  for- 
ward, nature  has  by  various  means  pro- 
vided so  effectually  for  the  restoration  of 
the  two  constituent  gases,  that  in  what- 
ever part  of  the  world,  and  at  whatever 
height  in  the  atmosphere,  air  is  taken, 
it  is  found,  when  chemically  examined, 
to  contain  azote  and  oxygen  in  exactly 
the  same  proportions. 

Quantity  of  air  required  for  Ventilation. 
If  the  question  were  solely  how  to  com- 
mand a  sufficient  supply  of  fresh  air,  it 
would  be  easily  solved ;  but  as  in  our 
climates  the  temperature  of  the  external 
atmosphere  is  in  winter  generally  very 
much  lower  than  is  necessary  for  comfort, 
we  have  at  the  same  time  to  provide  for 
the  maintenance  of  an  artificial  tempera- 
ture in  our  apartments,  by  allowing  the 
air  to  enter  no  faster  than  it  can  be  warm- 
ed. One  of  the  first  points,  therefore, 
to  be  considered,  is  the  amount  of  the 
supply  of  fresh  air  which  an  individual 
requires  for  comfort  and  health.  This, 
however,  is  a  point  on  which,  by  reason 
of  the  great  variety  of  circumstances  con- 
cerned, it  is  extremely  difficult  to  arrive 
at  any  satisfactory  conclusion. 


Dr.  Henry  estimates  tnat  an  adult  per- 
son makes,  on  the  average,  20  inspira- 
tions per  minute,  and  draws  into  his 
lungs  at  each  inspiration  20  cubic  inches 
of  air.  Peclet  allows  40  cubic  inches  for 
each  inspiration.  Taking  the  mean  of 
the  two  estimates,  we  have  600  cubic 
inches  expired  per  minute.  But,  accord- 
ing to  Dr.  Arnott,  air  expelled  from  the 
lungs  is  found  to  vitiate,  so  as  to  render 
unfit  for  respiration  twelve  times  its 
own  bulk  of  pure  air  ;  hence,  the  quan- 
tity of  air  spoiled  every  minute  by  the 
respiration  of  an  adult,  is  7200  cubic 
inches,  or  rather  more  than  4  cubic  feet. 
Dr.  Arnott,  however,  supposes  the  waste 
to  be  only  half  of  this  quantity.  But 
there  are  several  other  causes  of  deterio- 
ration besides  the  production  of  carbonic 
acid  from  the  lungs :  the  effluvia  and  va- 
por of  animal  matter  exuded  from  the 
whole  surface  of  the  body  is  not  less  in- 
jurious than  carbonic  acid  ;  and,  accord- 
ing to  M.  Seguin,  in  a  temperature  of 
60°,  about  3*  cubic  feet  of  air  per  minute 
is  charged  with  animal  vapor  transmitted 
through  the  skin  of  an  adult,  and  ren- 
dered unfit  for  respiration.  When  arti- 
ficial lights  are  used,  a  further  allowance 
must  be  made  for  the  waste  by  combus- 
tion. Besides,  air  is  required  for  various 
other  purposes  than  those  which  have 
now  been  mentioned.  It  acts  as  a  cooling 
power,  and  hence  the  supply  requisite 
for  comfort  depends  on  its  temperature. 
It  likewise  serves  to  carry  off  moisture 
from  the  skin,  and  therefore  its  state 
as  to  dryness  or  humidity  must  be  con- 
sidered. Dr.  D.  B.  Reid  found,  from 
observations  on  a  number  of  persons  as- 
sembled in  an  experimental  room,  that 
not  less  than  10  cubic  feet  per  minute 
should  be  allowed  to  each  individual  on 
the  average,  at  an  agreeable  temperature  ; 
but  that,  to  maintain  the  atmosphere  in 
all  its  purity,  a  much  larger  supply  would 
at  times  be  desirable.  On  the  whole, 
therefore,  we  may  conclude  that  10  cubic 
feet  of  fresh  air  per  minute,  for  each  in- 
dividual, is  the  smallest  allowance  that 
should  be  made  in  order  to  ensure  health- 
ful ventilation. 

The  experiments  of  Leblanc  upon  vi- 
tiated atmosphere  are  of  high  interest. 
The  quantity  of  carbonic  acid  in  the  at- 
mosphere in  the  normal  state,  has  been 
shown  by  the  Saussures  to  vary  from  3 
to  6  parts  in  10,000.  Leblanc  (Ann.  de 
Chim.  v.  223)  has  examined  the  quantity 
in  crowded  rooms,  theatres,  cities,  <fec. 
In  the  hospital  La  Pitie,  the  air  of  one  of 
the  wards  containing  54  patients  afford- 


664 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


P 


ed  3-1000  of  carbonic  acid  pas,  that  is,  5 
times  more  than  that  of  normal  air.  Under 
similar  circumstances,  at  the  Salpetriere, 
the  quantity  was  8-1000.  In  Dumas' s 
class  room,  after  a  lecture  of  an  hour  and 
a  half,  where  900  persons  were  present, 
the  carbonic  acid  amounted  to  1  per  cent., 
and  the  same  quantity  of  oxygen  had 
disappeared.  From  other  experiments, 
he  considers  this  a  maximum  quantity  for 
safety,  and  strongly  recommends  a  better 
ventilation  when  so  much  carbonic  acid 
is  present.  The  result  agrees  with  ex- 
periments made  in  this  country.  When 
the  atmosphere  is  deteriorated  by  burn- 
ing charcoal,  he  has  seen  death  produced 
when  3  per  cent,  of  carbonic  acid  was 
present  in  the  atmosphere.  In  all  such 
cases  of  death  from  stoves,  he  has  found 
carbonic  oxide  in  the  air,  and  he  attri- 
butes a  deleterious  effest  to  the  agency 
of  this  gas.  He  has  observed  1  per  cent, 
of  this  gas  to  destroy  an  animal  in  two 
minutes,  which  is  at  variance  with  the 
statement  of  Nysten.  This  observation 
explains  many  of  the  inconsistencies 
which  appeared  some  years  ago  in  the 
evidence  of  some  London  chemists  re- 
specting the  influence  of  Joyce's  stoves. 
It  is  quite  obvious  that  their  structure 
was  dangerous.  Leblanc  found  that  a 
candle  was  extinguished  in  air  containing 
4i  or  6  per  cent,  of  carbonic  acid.  In 
such  an  atmosphere,  life  may  be  kept  up 
for  some  time,  but  respiration  is  oppres- 
sive, and  the  animal  is  affected  with  very 
great  uneasiness.  Air  expired  from  the 
lungs  contains  about  4  per  cent,  of  carbo- 
nic acid,  and  hence  this  atmosphere  is 
noxious.  Even  3  per  cent,  in  the  atmo- 
sphere killed  birds. 

Dr.  Chowne  of  London,  has  enrolled 
a  patent,  for  improvement  in  ventilating 
rooms  and  apartments,  for  the  perfect 
efficacy  of  which,  we  believe,  there  can- 
not be  a  doubt,  and  on  a  principle  at  once 
most  simple  and  unexpected.  The  im- 
provements are  based  upon  an  action  in 
the  syphon  which  had  not  previously  at- 
tracted the  notice  of  anv  experimenter, 
viz.,  that  if  fixed  with  legs  of  unequal 
length,  the  air  rushes  into  the  shorter 
leg,  and  circulates  up,  and  discharges  it- 
self from  the  longer  leg.  It  is  easy  to 
see  how  readily  this  can  be  applied  to 
any  chamber,  in  order  to  purify  its  at- 
mosphere. Let  the  orifice  of  the  shorter 
leg  be  disposed  where  it  can  receive  the 
current,  and  lead  it  into  the  chimney  (in 
mines,  into  the  shafts),  so  as  to  convert 
that  chimney  or  shaft  into  the  longer  leg, 
and    you  have  at    once  the  circulation 


complete.  A  similar  air-syphon  can  be 
employed  in  ships,  and  the  lowest  holds 
where  disease  is  generated  in  the  close 
berths  of  the  crowded  seamen,  be  ren- 
dered as  fresh  as  the  upper  decks.  The 
curiosity  of  this  discovery  is,  that  air  in 
a  syphon  reverses  the  action  of  water, 
or  other  liquid,  which  enters  and  de- 
scends, or  moves  down  in  the  longer  leg, 
and  rises  up  in  the  shorter  leg. 

VEKDIGRIS,  or  acetate  of  copper,  is  a 
preparation  made  by  the  cake,  or  marc  of 
the  wine-presses  in  the  South  of  France. 
Thin  plates  of  copper  are  exposed  for 
some  time  to  their  action,  and  being  coat- 
ed with  verdigris,  the  operation  is  finish- 
ed by  pressure  into  loaves  of  the  sub- 
stance. 

VERDITER.  A  blue  pigment,  gene- 
rally prepared  by  decomposing  solution 
of  nitrate  ■  of  copper  by  the  addition  of 
chalk.  It  is  a  hydrated  percarbonate  of 
copper. 

VERMICELLI,  is  a  paste  of  wheat 
flour,  drawn  out  and  dried  in  slender  cyl- 
inders, more  or  less  tortuous,  like  worms, 
whence  the  Italian  name.  The  gruau  of 
the  French  is  wheat  coarsely  ground,  so 
as  to  free  it  from  the  husk  ;  the  hardest 
and  whitest  part,  being  separated  by  sift- 
ing, is  preferred  for  making  the  finest 
bread.  When  this  gruau  is  a  little  more 
ground,  and  the  dust  separated  from  it 
by  the  bolting-machine,  the  granular  sub- 
stance called  semoule  is  obtained,  which 
is  the  basis  of  the  best  pastes.  The  soft- 
est and  purest  water  is  said  to  be  neces- 
sary for  making  the  most  plastic  vermi- 
celli dough  ;  12  pounds  of  it  being  usu- 
ally added  to  50  pounds  of  semoule.  It 
is  better  to  add  more  semoule  to  the  wa- 
ter, than  water  to  the  semo-uh,  in  the  act 
of  kneading.  The  water  should  be  hot, 
and  the  dough  briskly  worked  while  still 
warm.  The  Italians  pile  one  piece  of  this 
dough  upon  another,  and  then  tread  it 
well  with  their  feet  for  two  or  three 
minutes.  They  afterwards  work  it  for 
two  hours  with  a  powerful  rolling-pin, 
a  bar  of  wood  from  10  to  12  feet  long, 
larger  at  the  one  end  than  the  other, 
having  a  sharp  cutting  edge  at  the  ex- 
tremity, attached  to  the  large  kneading- 
trough. 

When  the  dough  is  properly  prepared, 
it  is  reduced  to  thin  ribbons,  cylinders, 
or  tubes,  to  form  vermicelli  and  macaro- 
ni of  different  kinds.  This  operation  is 
performed  by  means  of  a  powerful  press. 
This  is  vertical,  and  the  iron  plate  or  fol- 
I  lower  carried  by  the  end  of  the  screw  fits 
I  exactly  into  a  'cast-iron  cylinder,  called 


vib] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


665 


the  bell,  like  a  sausage-machine,  of  which 
the  bottom  is  perforated  with  small  holes, 
of  the  shape  and  size  intended  for  the 
vermicelli.  The  bell  being  filled,  and 
warmed  with  a  charcoal  fire  to  thin  the 
dough  into  a  paste,  this  is  forced  slowly 
through  the  holes,  and  is  immediately 
cooled  and  dried  by  a  fanner  as  it  pro- 
trudes. When  the  threads  or  fillets  have 
acquired  the  length  of  a  foot,  they  are 
grasped  by  the  hand,  broken  off,  and 
twisted,  while  still  flexible,  into  any  de- 
sired shape  upon  a  piece  of  paper. 

The  macaroni  requires  to  be  made  of  a 
less  compact  dough  than  the  vermicelli. 
The  former  is  forced  through  the  perfo- 
rated bottom,  usually  in  fillets,  which  are 
afterwards  formed  into  tubes  by  joining 
their  edges  together  before  they  have  had 
time  to  become  dry.  The  lazagnes  are 
macaroni  left  in  the  fillet  or  ribbon  shape. 

VERMILION,  is  Ethiop's  mineral, 
heated  red-hot,  and  sublimed.  It  is 
e  bi-sulphuret  of  mercury.  In  a  cake 
it  is  cinnabar,  but,  in  powder,  vermilion. 

Chinese  Vermilion. — 'Take  quicksilver 
and  sulphur,  in  the  proportion  of  sixteen 
parts  of  the  former,  to  four  of  the  latter. 
After  powdering  the  sulphur,  place  the 
two  ingredients  in  an  earthen  jar,  the 
outside  of  which,  to  exclude  the  air,  must 
be  plastered  with  mud  and  salt,  to  the 
thickness  of  three  inches  and  a  half; 
place  an  iron  cover  on  the  mouth  of  the 
jar,  and  let  it  be  kept  constantly  moist. 
Place  the  jar  in  an  oven,  early  in  the 
morning,  and  at  the  same  hour  on  the 
next  morning  extinguish  the  fire  ;  at 
noon  take  it  out  of  the  oven,  and,  when 
cold,  break  the  jar  in  pieces,  and  take  out 
the  contents.  Pick  out  the  dross,  and 
then  reduce  the  rest  to  a  fine  powder: 
let  this  be  poured  into  a  large  jar  full  of 
water.  After  a  time,  a  thin  coating  will 
be  found  on  the  surface  of  the  water, 
which  must  be  skimmed  off,  and  a  por- 
tion of  the  water  let  off;  in  a  short  time 
this  process  must  be  repeated,  and  the 
third  time  let  all  the  water  be  drained  off. 
The  sediment  is  then  exposed  to  dry,  and 
taken  out  in  cakes. 

The  humid  process  of  Kirchoff  has  of 
late  years  been  so  much  improved,  as  to 
furnish  a  vermilion  quite  equal  in  bril- 
liancy to  the  Chinese.  The  following  pro- 
cess has  been  recommended:  Mercury  is 
triturated  for  several  hours  with  sulphur, 
in  the  eold,  till  a  perfect  ethions  is  form- 
ed; potash  ley  is  then  added,  and  the 
trituration  is  continued  for  some  time. 
The  mixture  is  now  heated  in  iron  ves- 
sels, with  constant  stirring  at  first,  but 


afterwards  only  from  time  to  time.  The 
temperature  must  be  kept  up  as  steadily 
as  possible  at  130°  Fahr.,  adding  fresh 
supplies  of  water  as  it  evaporates.  When 
the  mixture  which  was  black,  becomes, 
at  the  end  of  some  hours,  brown-red,  the 
greatest  caution  is  requisite,  to  prevent 
the  temperature  from  being  raised  above 
114°,  and  to  preserve  the  mixture  quite 
liquid,  while  the  compound  of  sulphur 
and  mercury  should  always  be  pulveru- 
lent. The  color  becomes  red,  and  bright- 
ens in  its  hue,  often  with  surprising  ra- 
pidity. When  the  tint  is  nearly  fine,  the 
process  should  be  continued  at  a  gentler 
heat,  during  some  hours.  Finally,  the 
vermilion  is  to  be  elutriated,  in  order  to 
separate  any  particles  of  running  mercu- 
ry. The  three  ingredients  should  be  very 
pure.  The  proportion  of  product  varies 
with  the  constituents.     {See  Mercury.) 

VIBRATION.  Reciprocal  motion.  In 
music,  that  regular  reciprocal  motion 
of  a  body,  which,  suspended  or  stretched 
between  two  fixed  points,  swings  or 
shakes  to  and  fro.  The  vibrations  of 
chords  are  the  source  of  the  different 
tones  they  emit.  If  two  strings  or  chords 
of  a  musical  instrument  merely  differ  in 
length,  their  tones,  that  is,  the  number 
of  vibrations  they  make  in  equal  times, 
are  in  the  reverse  ratio  of  their  lengths. 
If  they  differ  in  their  diameters  only,  their 
sounds  will  be  in  the  inverse  ratio  of  their 
diameters.  To  measure  the  tension  of 
strings,  let  us  conceive  them  stretched  by 
weights  attached  to  their  ends ;  then  their 
sounds  will  be  in  the  direct  ratio  of  the 
square  roots  of  the  weights  stretching 
them ;  that  is,  the  pitch  of  a  string 
stretched  by  a  weight  equal  to  4  will  be 
an  octave  above  the  pitch  of  a  string 
stretched  by  a  weight  1. 

Vibration  in  mechanics  is  the  recipro- 
cating motion  of  a  body,  as  of  a  pendu- 
lum, a  musical  chord,  or  elastic  plate. 
The  term  oscillation  is,  however,  morp 
frequently  used  to  denote  a  slow  recipro- 
cating motion,  as  that  of  the  pendulum 
which  is  produced  by  the  action  of  gravi 
ty  on  the  whole  mass  of  the  body  ;  whil# 
vibration  is  generally  confined  to  a  motion 
with  quick  reciprocations,  as  that  of  a 
sonorous  body,  and  which  proceeds  from 
the  reciprocal  action  of  the  molecules  of 
the  body  on  each  other  when  their  state 
of  equilibrium  has  been  disturbed. 

Metallic  rods  or  glass  tubes  ma}*  vibrate 
longitudinally  like  stretched  chords.  In 
this  case  they  divide  themselves  sponta- 
neously into 'several  parts,  which  vibrate 
in  unison :  and  are  separated  by  v-odes,  ot 


666 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[VEB 


parts  which  remain  at  rest.  The  extreme 
parts  are  shorter  than  the  others,  -which 
are  all  of  equal  length  ;  but  the  vibrations 
of  all  the  parts  are  synchronous.  This 
sort  of  vibration  may  be  induced  in  a  slip 
or  tube  of  glass,  by  holding  it  between 
the  fingers,  in  the  middle,  and  rubbing 
it  longitudinally  with  a  piece  of  moist 
cloth,  when  it  will  emit  a  very  acute 
sound. 

Vibrations  of  Elastic  Plates. — All  elastic 
solid  bodies,  when  put  into  a  state  of  vi- 
bration, may  be  conceived,  in  reference 
to  the  internal  motions  of  their  mole- 
cules, as  spontaneously  separating  them- 
selves into  parts,  each  of  which  vibrates 
independently  of  the  others,  and  in  such 
a  manner  that  the  molecules  of  one  part 
are  at  every  instant  moving  in  a  direction 
opposite  to  that  of  the  molecules  of  the 
adjacent  part.  It  follows  that  the  points 
of  separation  between  two  parts  partici- 
pate neither  in  the  motion  of  the  one  nor 
of  the  other,  and  consequently  remain  at 
rest.  In  the  case  of  thin  elastic  plates, 
the  continuity  of  these  points  forms  lines 
of  repose,  or  nodal  lines,  the  forms  and 
positions  of  which  are  detected  by  placing 
the  vibrating  plate  in  a  horizontal  posi- 
tion, and  strewing  a  small  quantity  of 
fine  sand  over  its  upper  surface.  This 
ingenious  mode  of  determining  the  nodal 
lines  was  pointed  out  by  Galileo  in  his 
Dialogues,  and  was  practised  by  Chladni 
( Traite  d' ' Acoustique)  and  more  recently 
by  Savart  in  his  numerous  experiments 
on  this  subject. 

These  lines  assume  a  great  variety  of 
forms,  depending  on  the  figure  of  the 
plate,  the  position  of  the  point  or  points 
at  which  it  is  fixed,  and  the  rapidity  and 
direction  of  the  motion  by  which  the  vi- 
bration is  communicated  to  it.  Circular 
plates  afford  numerous  different  systems 
of  nodal  lines.  When  the  plate  is  fixed 
at  its  centre  between  two  knobs  or  points 
held  fast  by  a  vice,  two  nodal  lines  are  in 
general  produced,  crossing  each  other  ;it 
the  centre.  By  applying  the  finger  to 
the  plate  at  a  suitable  point,  so  as  to 
interrupt  the  vibration,  three  of  those 
lines  may  be  formed.  Disks  of  metal  fur- 
nish a  number  of  nodal  lines,  dividing 
the  circle  into  numerous  sectors.  In  cer- 
tain circumstances  these  straight  nodal 
lines  are  intersected  by  a  greater  or  small- 
er number  of  concentric  circular  lines ; 
the  circular  lines  may  also  exist  by  them- 
selves ;  and  sometimes  the  nodal  lines 
assume  the  form  of  the  branches  of  a 
hyperbola. 

VICE,  used  by  smiths,  is  a  common 


instrument  with  two  cheeks,  made  to  hold 
or  bite  by  a  screw  of  power. 

The  vice  for  glaziers  is  one  by  which 
prepared  lengths  of  lead  are  drawn 
through  it  in  slips  for  windows,  the  hole 
or  tool  being  the  form  of  the  slips,  and 
the  force  applied  by  a  winch  handle. 

VINEGAR.  Under  the  head  Acetic 
Acid  is  given  the  mode  of  making  vine- 
gar from  alcohol.  Under  the  present 
head  will  be  noticed  the  manufacture 
from  fermenting  vegetable  juices.  Al- 
most all  the  vinegar  of  this  country  is 
made  from  cider.  It  is  only  lately,  how- 
ever, that  any  regularity  or  care  in  the 
manufacture  was  exhibited. 

The  old  mode  was  to  put  out  cider  or 
water  and  molasses  in  a  cask,  exposed  to 
the  sun,  until  it  became  fully  fermented. 
(See  Fekmentation.) 

The  oxygen  of  the  atmosphere,  al- 
though it  is  not  now,  as  was  once  believ- 
ed to  be,  the  only  acidifier,  still  it  is  the 
great  one,  and  vinegar  is  formed  by  the 
cider  parting  with  carbonic  acid  gas, 
which  it  cannot  do  without  absorbing 
oxygen.  The  reasonable  way,  then,  to 
make  vinegar  rapidly  and  surely,  is  to 
expose  the  cider  as  much  as  possible  to 
the  atmosphere.  The  new  way,  and  what 
is  supposed  by  many,  incorrectly,  to  be  a 
patent  way  to  make  vinegar,  is  to  let  the 
cider  percolate  over  a  very  exposed  sur- 
face. The  apartment  where  it  is  made  is 
freely  exposed  to  the  air,  and  is  kept  at  a 
temperature  of  above  60°.  The  cider  is 
left  to  run  in  small  streams  into  troughs 
with  bottoms  full  of  small  holes,  then 
from  that  over  very  fine  wood  shavings, 
such  as  soft  maple,  and  let  these  be  ful- 
ly exposed  to  the  air  and  resting  on  a 
slatted  bottom  made  of  clean  bows  or 
laths,  below  which  the  vessel  for  receiv- 
ing it  should  be  placed  ;  vinegar  can  be 
made  from  molasses  and  water,  grapes, 
corn  stalks,  beet  roots,  and  many  other 
substances,  by  this  process  in  a  few  days. 
Cider,  however,  makes  the  best  vinegar. 
Many  modifications  (for  cheapness)  of 
the  above  plan  may  be  resorted  to,  the 
grand  secret  being  the  exposure  of  the 
liquids  to  be  changed  into  vinegar  in 
layers  or  strata  to  the  oxygen  of  the  at- 
mosphere. 

The  following  is  the  plan  cf  making 
vinegar  at  present  practised  in  Paris. 
The  wine  destined  for  vinegar  is  mixed 
in  a  large  tun  with  a  quantity  of  wine 
lees,  and  the  whole  being  put  into  sacks, 
placed  between  the  plates  of  a  press,  the 
liquid  matter  is  pressed  out. 

What  passes  through  is  put  into  large 


<•] 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


667 


casks,  set  upright,  having  a  small  aper- 
ture in  their  top.  In  these  it  is  exposed 
to  the  heat  of  the  sun  in  summer,  or  to 
the  heat  of  a  stove  in  winter. 

Fermentation  comes  on  in  a  few  days. 
If  the  heat  should  then  rise  too  high,  it 
is  lowered  by  cool  air,  and  the  addition  of 
fresh  wine.  In  summer  the  process  is 
generally  completed  in  a  fortnight ;  in 
winter  double  the  time  is  requisite.  The 
vinegar  is  then  rim  off  into  barrels,  which 
contain  several  chips  of  beech  wood  to 
clarify  it :  in  about  a  fortnight  it  is  fit  for 
sale. 

Almost  all  the  vinegar  of  the  north  of 
France  being  prepared  at  Orleans,  the 
manufactory  of  that  place  has  acquired 
such  oelebnty  as  to  render  their  process 
worthy  of  a  separate  consideration. 

The  Orleans  casks  formerly  contained 
nearly  200  gallons  of  wine,  but  at  present 
only  about  half  that  quantity.  Those 
which  have  been  already  used  are  pre- 
ferred. They  are  placed  in  three  rows 
one  over  another,  and  in  the  top  have  an 
opening  of  two  inches  diameter,  which 
has  a  bung  fitting  close;  there  is  another 
spill  hole  on  the  side  to  admit  the  air. 
Wine  a  year  old  is  preferred  for  making 
vinegar,  and  is  kept  in  adjoining  casks, 
containing  beech  shavings,  to  which  the 
lees  adhere. 

The  vinegar  from  sugar  is  made  as  fol- 
lows : — Ten  pounds  of  sugar  are  added 
to  eight  gallons  of  water,  with  yeast  and 
raisins  of  grape  cuttings,  to  assist  in  the 
fermentation  ;  twelve  pints  of  bruised 
gooseberries,  or  other  fruits,  are  added  ; 
and,  by  a  process  similar  to  that  for  cider, 
good  vinegar  is  soon  produced. 

By  distillation  the  coloring  matter  in 
mucilage  is  separated ;  but  the  fragrant 
odor  is  generally  replaced  by  an  empy- 
reumatic  one. 

The  specific  gravity  varies  from  1-005 
to  1-015. 

The  Vinegar  of  Wood,  as  it  comes  over 
in  the  first  distillation,  with  its  tar  and 
empyreumatic  oils,  is  extensively  used  in 
preserving  meat  and  all  animal  substan- 
ces. A  single  dipping,  or  washing,  de- 
stroys all  tendency  to  putrescence  and 
decomposition,  and  operates  like  its 
smoke,  in  curing  hams,  fish,  &c.  This  pro- 
perty is  due  to  the  presence  of  creosote. 

It  is  also  found  to  be  highly  efficacious 
in  checking  putrescence  in  wounds  and 
ulcers,  and  in  arresting  scrofula,  and 
obstinate  local  inflammations. 

It  is  prepared  by  the  destructive  distil- 
lation of  any  kind  of  wood.  It  is  then 
ro-distjlled  in  a  copper  still,  leaving  one- 


j  fifth  residuum  of  tough,  tarry  matter. 
The  product,  brown  vinegar,  is  then  dis- 
tilled a  third  time,  and  absorbed  by  lime, 
dried,  and  torrified  as  calcareous  salt. 
This  is  decomposed  by  sulphuric  acid, 
and  the  product  is  pure  acetic  acid.  At 
75°,  one  part  with  11  of  water  is  the  com- 
mon distilled  vinegar  of  medicine. 

Pyroligneous  acid  is  prepared,  quite 
colorless,  by  distillation  trom  the  acetate 
of  lime  above  mentioned,  is  of  sp.  gr. 
1-063,  and  is  seven  times  stronger  than 
table,  or  pickling  vinegar,  and  requires 
seven  volumes  of  water  for  culinary  pur- 
poses. A  piece  of  meat,  or  a  whole  ani- 
mal dipped  in  it,  or  sponged,  or  brushed 
with  it,  remains  sweet  and  free  from 
putrescence  for  months  or  years. 

Four-thieves  Vinegar. — In  two  pints  of 
strong  acetic  acid,  for  7  days,  digest  1  oz. 
of  rosemary-tips  and  of  sage-leaves,  i  an 
oz.  of  lavender-naps,  and  1  scruple  of 
cloves ;  (some  add  half  a  clove  of  garlic.) 
Press  well,  and  filter. 

VIOLET  DYE,  is  produced  by  a  mix- 
ture of  red  and  blue  coloring-matters, 
which  are  applied  in  succession.  Silk  is 
dyed  a  fugitive  violet  with  either  archil 
or  Brazil  wood ;  but  a  fine  fast  violet,  first 
by  a  crimson  with  cochineal,  without  tar- 
tar or  tin  mordant,  and  after  washing,  it 
is  dipped  in  the  indigo  vat.  A  finish  is 
sometimes  given  with  archil.  A  violet  is 
also  given  to  silk,  by  passing  it  through 
a  solution  of  verdigris,  then  through  a 
bath  of  logwood,  and,  lastly,  through 
alum  water.  A  more  beautiful  violet 
may  be  communicated  by  passing  the  al- 
umed  silk  through  a  bath  of  Brazil  woody 
and  after  washing  it  in  the  river,  through 
a  bath  of  archil. 

To  produce  violets  on  printed  calicoes, 
a  dilute  acetate  of  iron  is  the  mordant, 
and  the  dye  is  madder.  The  mordanted 
goods  should  be  well  dunged. 

VITRIOL,  WHITE,  is  composed  of 
sulphuric  acid  and  oxide  of  zinc. 

White  vitriol,  or  sulphare  of  zinc,  is 
composed  of  40  parts  or  sulphuric  acid, 
and  41  parts  of  zinc,  also  in  the  state  of 
oxide.     (See  Zinc.) 

Blue  Vitriol  is  the  sulphate  of  copper, 
obtained  simply  by  evaporating  the  waste 
water  of  mines  ;  or,  sometimes,  by  roast- 
ing copper  pyrites.  In  other  cases  the 
sulphate  is  converted  into  copper,  by  im- 
mersing iron  in  the  water,  and  then 
treated  with  sulphuric  acid.  It  is  often 
used  as  an  emetic,  and  applied  to  indo- 
lent ulcers,  and  as  a  coilyrium. 

Green  Vitriol,  or  Copperas,  is  protosul- 
phate  of  iron,  made  by  exposing  iron  py- 


668 


CYCLOPEDIA    OF   THE    USEFUL  ARTS. 


[vol 


rites  to  air  and  water.  It  is  then  digest- 
ed with  iron  turnings,  to  get  rid  or  the 
excess  of  sulphuric  acid.  {See  Cop- 
peras.) 

VOLTAIC  ELECTKICITY.  The  phe- 
nomena resulting  from  the  evolution  of 
electricity  by  chemical  action,  as  mani- 
fested by  that  important  instrument  of 
electro-chemical  research  called  the  Vol- 
taic Battery,  are  usually  included  under 
the  above  term.  Whenever  substances 
act  chemically  upon  each  other,  their 
electrical  states  are  disturbed  ;  but  the 
electricity  thus  evolved  is.  in  ordinary 
cases,  so  lost  and  dissipated  as  to  escape 
observation.  It  may,  however,  be  ren- 
dered manifest  by  the  following  simple 
arrangements  :  When  a  plate  of  pure 
zinc  (or  of  common  zinc  rubbed  over  or 
amalgamated  with  mercury)  is  dipped 
into  a  glass  of  very  dilute  sulphuric  acid, 
little  or  no  action' is  observed;  nor  does 
any  thing  happen  when  a  similar  plate  of 
silver  is  placed  in  the  same  cup  of  acid, 
provided  the  metals  be  kept  apart  from 
each  other.  But  if  the  zinc  and  silver  be 
brought  into  contact,  at  their  extremities 
out  of  the  liquid,  the  water  is  decompos- 
ed ;  its  oxygen  combines  with  the  zinc 
to  form  oxide  of  zinc,  which  is  dissolved 
by  the  acid;  and  its  hydrogen  passes 
over  to  the  surface  of  the  silver,  where  it 
collects,  and  ultimately  escapes  in  gase- 
ous globules.  These  phenomena  are  fur- 
ther connected  with  the  production  of  a 
continuous  current  of  electricity  passing 
from  the  zinc  across  the  water  to  the  sil- 
ver, and  again  from  the  silver,  by  metal- 
lic contact,  to  the  zinc,  in  the  direction 
of  the  wire  or  connection.  It  is  not  ne- 
cessary that  the  metals  should  be  con- 
nected exactly  by  juxtaposition ;  but  it  is 
necessary  to  the  establishment  of  the  con- 
tinuous electric  current  that  they  should 
be  somewhere  in  contact,  or  at  least  con- 
nected by  what  is  usually  termed  a  per- 
fect conductor.  By  modifying  the  pre- 
ceding arrangement,  so  that  the  metallic 
contact  between  the  plates  be  made  out 
of  the  vessel,  the  electric  current  takes 
the  same  direction,  travelling  through  the 
liquid  from  the  zinc  or  generating"  plate 
to  the  conducting  plate,  and  through  the 
wires  back  again  to  the  zinc.  Here  again 
the  zinc  is  oxidized  and  dissolved,  and 
hydrogen  is  liberated  upon  the  silver 
plate  ;  but  the  moment  that  the  circuit  is 
broken,  by  parting  the  wires,  these  ac- 
tions cease,  because  the  electric  current 
ceases  to  flow.  It  is  evident  that  various 
substances  may  be  interposed  between 
the  wires,  or  they  may  be  immersed  into 


different  liquids ;  and  provided  these  are 
capable  of  transmitting  electricity,  the 
current  will  still  pass,  and  its  phenomena 
under  a  variety  of  circumstances  may  be 
studied.  In  this  arrangement  the  end  of 
the  wire  from  the  silver  plate  is  the 
emitting,  and  of  that  from  the  zinc  the 
receiving  point  or  pole  ;  hence  these  have 
been  termed,  in  reference  to  the  common 
electrical  machine,  the  positive  and  nega- 
tive poles.  Mr.  Faraday,  with  a  view  of 
avoiding  certain  misapprehensions  to 
which  these  terms  give  rise,  calls  them  the 
electrodes;  the  posiitve  electrode  he  further 
terms  the  anelectrod-e,  and  the  negative 
the  catelectrode,  or  anode  and  kathode. 

In  the  preceding  paragraph  it  has  been 
assumed  that  the  generating  metal  is  zinc, 
the  conducting  or  conveying  metal  silver, 
and  that  the  intermediate  liquid  is  dilute 
sulphuric  acid.  A  number  of  other  me- 
tals may  be  substituted  for  the  above ; 
namely,  for  the  zinc,  cadmium  for  in- 
stance, or  iron  ;  and  for  the  silver,  pla- 
tinum, gold,  or  copper.  Manv  liquids 
may  also  be  substituted  for  the  dilute  sul- 
phuric acid  ;  the  requisite  condition  be- 
ing that  one  of  the  metals  shall  be  chemi- 
cally acted  on,  whilst  the  other  is  indif- 
ferent, or  at  least  not  acted  on  by  the 
liquid  to  the  same  extent.  And  the  cur- 
rent is  always  in  the  direction  above  re- 
presented ;  that  is  to  say,  passes  from 
the  metal  most  attacked  to  that  least  at- 
tacked, whenever  the  communication  is 
perfect  or  the  circle  closed.  In  the  above 
cases  also  certain  forms  of  charcoal,  which 
are  excellent  conductors  of  electricity, 
may  be  substituted  for  the  conveying 
metal,  or  passive  element  of  the  arrange- 
ment. Another  requisite  condition  to 
the  phenomena  properly  called  Voltaic  is 
that  the  interposed  fluid  shall  conduct : 
and  further,  that  it  shall  be  capable  of 
that  form  of  decomposition  which  Fara- 
day has  designated  electrolysis,  that  is, 
resolvable  into  its  elements  by  the  elec- 
tric current. 

The  quantity  of  electricity  generated  in 
the  above  instances  depends  chiefly  upon 
the  superficial  extent  of  the  metals  con- 
cerned, and  upon  the  activity  of  the  li- 
quid acting  upon  the  generating  metal ; 
and  that  it  is  considerable,  even  where 
small  surfaces  and  weak  acids  are  used, 
is  manifest  by  the  violence  with  which 
the  magnetic  needle  of  the  galvanometer 
is  deflected.  But  in  the  above  described 
arrangements,  the  intensity  of  the  elec- 
tricity is  very  feeble  ;  and  in  order  to  atr 
tain  this,  and  to  give  the  current  that  ap- 
parent impetus  which  it  requires  to  tra- 


vol] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


669 


verse  bad  conductors,  and  easily  to  effect 
electro-chemical  decompositions,  it  be 
come*  necessary  to  repeat  the  metallic  al- 
ternations ;  or,  in  other  words,  to  employ 
a  properly  arranged  succession  of  gene- 
rating, conducting,  and  electrolytic  sub- 
stances. This  leads  to  the  grand  disco- 
very of  Volta*  namely,  the  construction 
of  the  Voltaic  Pile  or  Battery. 

In  this  arrangement,  which,  like  the 
simple  circles,  admits  of  infinite  varieties, 
the  metals  generally  used  are  zinc  on  the 
one  hand,  and  copper  or  silver  or  plati- 
num on  the  other.  The  alternation..  >ri- 
ginally  adopted  by  Volta,  and  which  are 
quite  effectual,  were  zinc,  silver,  and  flan- 
nel or  pasteboard  soaked  in  acid ;  and 
these  were  repeated  according  to  the  ef- 
fects that  were  to  be  obtained.  The  in- 
convenience of  arrangement  led  him, 
however,  to  various  modifications  of  it ; 
and,  among  them,  to  the  use  of  a  series 
of  separate  vessels,  which  he  called 
the  crown  of  cups  (couronne  des  tasses,) 
and  which,  slightly  modified,  has  since 
been  very  generally  adopted.  The  flan- 
nel is  rejected,  and  in  its  place  a  cup  of 
dilute  acid,  or  other  proper  electrolyte,  is 
substituted  ;  so  that  each  silver  and.  zinc 
plate  are  in  metallic  communication, 
though  in  separate  vessels  :  the  arrange- 
ment being  zinc,  acid,  silver;  zinc,  acid, 
silver,  &c.  Here  the  direction  of  the 
electric  current  is  the  same  as  in  the  sim- 
ple circle,  namely,  from  the  zinc  through 
the  liquid  to  the  silver:  but  in  this  form 
of  the  apparatus,  for  the  mere  conveni- 
ence of  carrying  on  the  series,  the  con- 
ducting wire  connected  with  the  first  zinc 
plate  has  a  supernumerary  silver  one  at- 
tached to  it,  and  that  with  the  last  silver 
plate  a  supernumerary  zinc  plate ;  so  that 
much  confusion  has  arisen  in  regard  to 
the  direction  of  the  current  in  these 
cases,  in  consequence  of  calling  what  is 
here  the  silver  extreme  the  negative  pole, 
and  the  zinc  extreme  the  positive  pole  ; 
whereas  it  is  in  fact  the  reverse,  and  the 
circulation  of  the  current  goes  on  through 
the  electrodes  precisely  as  in  the  simple 
circle.  But  though  the  direction  of  the 
current  is  the  same,  and  the  absolute 
quantity  of  travelling  or  circulating  elec- 
tricity not  increased,  the  case  as  regards 
intensity  is  very  different ;  and  with  nu- 
merous series  arranged  as  above  we  ob- 
tain, on  removing  the  electrodes  (which 
in  this  experiment  ought  to  consist  of 
pointed  pieces  of  well-burned  boxwood 
charcoal)  a  little  from  each  other,  a  most 
brilliant  and  continuous  current  of  fire, 
luminous,  so  that  the  eye  can  scarcely 


endure  it,  and  capable  of  overcoming  ob- 
stacles and  traversing  conductors  and 
electrolytes  in  a  way  essentially  different 
from  that  of  the  simple  circuit.  Yet, 
even  with  all  these  energetic  phenomena, 
and  with  a  quantity  of  circulating-  elec- 
tricity far  beyond  any  thing  which  the 
most  powerful  frictional  machines  can  af- 
ford, the  intensity  is  still  insufficient  to 
penetrate  a  thin  layer  of  card  or  paper, 
or  to  make  its  way  through  non-conduct- 
ing obstacles,  as  it  does  in  the  case  of  the 
discharge  of  the  Leyden  jar  or  battery. 
And  now,  if  the  hands  be  well  moistened 
with  salt  and  water,  so  as  to  overcome 
the  non-conducting  tendency  of  the  cu- 
ticle, and  the  body  be  made  part  of  the 
circuit,  an  extraordinary  and  unendura- 
ble sensation  is  perceived,  which  is  in 
fact  a  continuous  shock.  By  the  same 
means  wires  may  be  ignited,  metals  burn- 
ed, combustibles  exploded,  magnets 
made,  and  galvanometers  affected  at  any 
distance  from  the  pile,  provided  the  con- 
ducting communication  is  perfect.  Thus 
it  is  that  this  power  has  been  used  to 
blast  rocks,  to  explode  gunpowder  under 
water,  and  to  communicate  telegraphic 
signs,  as  in  the  arrangement  of  Professors 
Morse  &  Wheatstone,  Messrs.  Bain, 
House,  &c. 

But  the  most  important  modification 
of  this  instrument  is  that  suggested  by 
Mr.  Daniell,  and  which  he  terms  "  a 
constant  battery."  In  all  the  preceding 
arrangements  the  electrical  power  is  lia- 
ble to  fluctuation  ;  and  after  a  time  va- 
rious causes  induce  such  a  falling  off  of 
its  evolution  a3  to  render  them  inconve- 
nient, or  even  useless,  where  continuous 
or  regular  action  is  required.  In  Wol- 
laston's  battery,  for  instance,  which  is  the 
best  of  them,  several  circumstances  com- 
bine to  render  it  inconstant  in  its  action  : 
the  adhesion  of  hydrogen  to  the  copper 
plate,  and  the  precipitation  of  zinc  upon 
it,  the  saturation  of  the  acid  by  oxide  of 
zinc,  and  the  local  action  which  common 
zinc  induces,  are  perhaps  the  principal 
sources  of  the  above-mentioned  irregu- 
larity and  inconstancy.  In  Mr.  Daniell's 
arrangement  those  inconveniences  are  to 
a  great  extent  obviated  ;  and  although  it 
is  more  complicated  than  the  preceding, 
its  constant  and  regular  action,  when  it 
is  properly  constructed,  amply  repays  the 
additional  trouble  and  expense  :  'there 
are,  indeed,  many  investigations  which 
can  scarcely  be  carried  on  without  it. 
(See  Electro  Metallurgy,  for  a  view  of 
Daniell's  battery.) 

Under  the  articles  Electro  Metallur- 


670 


CYCLOPEDIA    OF   THE    USEFUL   ARTS, 


[WAT 


or  and  Telegraph  are  found  descriptions 
of  Voltaic  batteries. 

Not  only  are  the  ultimate  elements  of 
binary  compounds  evolved  in  obedience 
to  certain  uniform  laws,  but  proximate 
elements  are  also  similarly  separated. 
Thus,  when  sulphate  of  soda,  nitrate  of 
potassa,  and  other  neutral  salts,  are  sub- 
jected in  aqueous  solution  to  the  action 
of  the  current,  the  respective  acids  travel 
with  the  oxygen  to  the  anode,  and  the 
alkalies,  oxides,  or  bases,  with  the  hy- 
drogen to  the  cathode.  Faraday  terms 
substances  susceptible  of  these  transfer- 
ences ions,  and  those  which  go  to  the 
anode  anions  /  those  to  the  cathode  ca- 
tions :  thus  doing  away  with  the  less  de- 
finite terms  of  electro-negative  and  electro- 
positive bodies. 

WAINSCOT.  In  architecture,  the 
framed  lining  in  panels  wherewith  a  wall 
is  faced.  The  wood  originally  used  for 
this  purpose  being  a  species  of  foreign 
oak,  that  wood  has  acquired  the  name 
from  the  purpose  to  which  it  was  thus 
applied. 

WAIST.  That  part  of  the  gun-deck 
between  the  fore  and  main  masts. 

WATCH.  A  well-known  portable 
machine,  moved  by  a  spring,  for  mea- 
suring time.  When  executed  in  the 
most  perfect  manner,  it  is  called  a  chro- 
nometer, and  used  in  navigation  for  de- 
termining differences  of  longitude. 

Watches  are  said  to  have  been  made 
at  Nuremberg  so  early  as  1477  ;  but  it 
18  uncertain  how  far  the  watches  then 
constructed  resembled  those  which  now 
go  by  that  name.  Some  of  the  early 
ones  were  very  small,  in  the  shape  of  a 
pear,  and  sometimes  sunk  or  fitted  into 
the  top  of  a  walking-stick.  As  time- 
keepers, watches  could  have  very  little 
value  before  the  application  of  the  spiral 
spring  as  a  regulator  to  the  balance.  The 
merit  of  this  excellent  invention  has  been 
claimed  by  Hooke  and  Huygens  ;  but  it 
seems  established  by  unquestionable  evi- 
dence that  the  priority  belonged  to 
Hooke  by  at  least  fifteen  years.  The 
date  of  the  invention  is  about  165S. 
Hooke's  first  balance  spring  was  straight, 
and  acted  on  the  balance  in  a  very  im- 
perfect manner ;  but  he  soon  perceived 
its  defects,  and  attempted  to  obviate 
them  by  adopting  first  the  cylindrical, 
and  afterwards  the  flat  spiral.  The  lat- 
ter appears  to  have  been  applied  to 
watches  before  the  publication  of  Huy- 
gens' claim  in  1675. 

WATCH-MAKING.  The  wheels  in 
spring-clocks,  and  in  watches,  are  urged 


on  by  the  force  C  5  a  spiral  spring,  con- 
tained in  a  hollow  cylindrical  barrel,  or 
box,  to  which  one  end  of  a  cord  or  chain 
is  fixed,  and  lapping  it  round  the  barrel, 
for  several  turns  outside  :  the  other  end 
is  fixed  to  the  bottom  of  a  solid,  shaped 
like  the  frustrum  of  a  cone,  known  by 
the  name  of  the  fusee,  having  a  spiral 
groove  cut  on  it :  on  the  bottom  of  this 
cone,  or  fusee,  the  first  or  great  wheel 
is  put.    (See  Fusee.) 

The  arbor,  on  which  the  spring-barrel 
turns,  is  so  fixed  in  the  frame  that  it 
cannot  turn  when  the  fusee  is  winding 
up  :  the  inner  end  of  the  spring  hooks 
on  to  the  barrel  arbor,  and  the  outer 
end  hooks  to  the  inside  of  the  barrel. 
Now,  if  the  fusee  is  turned  round  in  the 
proper  direction,  it  will  take  on  the  cord 
or  chain,  and,  consequently,  take  it  off 
from  the  barrel.  This  bends  up  the 
spring ;  and,  if  the  fusee  and  great  wheel 
are  left  to  themselves,  the  force  exerted 
by  the  spring  in  the  barrel,  to  unbend 
itself,  will  make  the  barrel  turn  in  a 
contrary  direction  to  that  by  which  it 
was  bent  up.  This  force  of  the  spring 
unbending  itself,  being  communicated 
to  the  wheels,  will  set  them  in  motion, 
and  they  will  move  with  considerable 
velocity. 

Their  time  of  continuing  in  motion 
will  depend  on  the  number  of  turns  of 
the  spiral  groove  on  the  fusee,  the  num- 
ber of  teeth  in  the  first  or  great  wheel, 
and  on  the  number  of  leaves  in  the 
pinion  upon  which  the  great  wheel 
acts,  &c. 

The  wheels,  in  any  sort  of  movement, 
when  at  liberty,  or  free  to  turn,  and 
when  impelled  by  a  force,  whether  it  is 
that  of  a  weight  or  of  a  spring,  would 
soon  allow  this  force  to  terminate  ;  for, 
as  the  action  of  the  force  is  constant 
from  its  first  commencement,  the  wheels 
would  be  greatly  accelerated  in  their 
course,  and  it  would  be  an  improper  ma- 
chine to  register  time  or  its  parts.  The 
necessity  of  checking  this  acceleration, 
and  making  the  wheels  move  with  a  uni- 
form motion,  gave  rise  to  the  invention 
of  the  escapement,  or  'scapement,  as  it  is 
commonly  called.  To  effect  this,  an  al- 
ternate motion  was  necessary,  which  re- 
quired no  small  effort  of  human  ingenuity 
to  produce. 

The  escapement  is  that  part  of  a  clock 
or  watch,  connected  with  the  beats  whioh 
we  hear  it  give  ;  and  these  beats  are  the 
effects  of  the  moving  power,  carried  for- 
ward by  means  of  the  wheels  in  the 
movement  to  the  last  one,  which  is  call 


wat] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


671 


ed  the  swing-wheel  in  a  pendulum  clock, 
and  the  balance-wheel  in  a  watch. 

The  teeth  of  this  wheel  act  on  the 
pallets  or  verge,  which  are  of  various 
shapes,  and  which  form  the  most  essen- 
tial part  in  a  scapement ;  they  drop  from 
eacli  tooth  of  the  swing  or  balance-wheels, 
on  their  respective  pallets,  giving  one 
beat  or  impulse  to  the  pendulum  or  bal- 
ance, in  order  to  keep  up  or  maintain 
their  motion  ;  and,  were  it  not  for  the 
pallets,  which  alternately  stop  the  teeth 
of  the  swing  or  balance-Wheels,  the  mo- 
tive-force would  have  no  check. 
•  Hence  it  is,  that,  by  this  mechanism  of 
the  'scapement,  the  wheels  in  the  move- 
ment are  prevented  from  having  their 
revolutions  accelerated. 

WATER  CLOCK.  A  contrivance  for 
measuring  time  by  the  flow  of  water. 

WATER  GAS.  This  name  is  applied 
to  the  compound  gases  derived  from  the 
decomposition  of  resin  and  the  admix- 
ture ot  hydrogen  from  decomposition  of 
water.  So  long  back  as  1833,  Mr.  Jobard, 
in  France,  produced  hydrogen  by  the 
decomposition  of  water,  and  applied  it 
to  the  purposes  of  Rumination  with 
great  success.  He  obMined  his  hydro- 
gen by  the  decomposition  of  steam  in 
vertical  retorts,  filled  with  incandescent 
coke,  and  unites  the  gas  just  as  it  is  form- 
ed with  bicarburetted  hydrogen  produced 
by  the  distillation  of  any  hydro-carburet, 
as  oil,  tar,  naphthaline,  and  other  pro- 
ducts at  present  rejected  in  ordinary  gas 
works. 

In  1848,  Mr.  S.  White  patented  in 
England  an  apparatus  for  the  manufac- 
ture of  gas  from  water  and  common  tar, 
or  resin,  &c.  The  apparatus  consisted 
of  three  retorts,  placed  on  a  stove,  two  of 
which  are  filled  with  charcoal,  and  thin 
pieces  of  iron,  and  the  other  with  iron 
chains,  hanging  from  a  centre  bar.  The 
first  two  retorts  are  for  the  decomposi- 
tion of  water,  which  is  regularly  supplied 
by  a  syphon  pipe,  passing  through  and 
into  the  centre  of  the  retort.  The  water 
in  passing  through  the  heated  material 
becomes  converted  into  pure  hydrogen. 
It  then  passes  into  the  third  retort,  to 
receive  its  full  dose  of  bicarburet  of  hy- 
drogen, which  is  prepared  from  common 
tar,  resin,  or  similar  substances,  passing 
or  dropping  on  the  red-hot  chain  from  a 
syphon  tub,  which  regulates  its  supply. 
This  causes  the  tar  or  melted  resin  to 
throw  off  defiant  gas  in  abundance.  The 
mixed  gases  are  then  conveyed  into  the 
gasometer  without  purification,  none  be- 
ing required.    Its  great  advantages  are 


that  it  only  requires  an  apparatus,  which 
may  be  small,  simple,  and  cheap ;  and 
the  beautiful  light  produced  is  superior 
to  the  ordinary  coal-gas.  It  may  be  man- 
ufactured on  small  concerns,  as  manu- 
factories, hotels,  and  large  mansions ; 
and  may  be  burned  in  any  room  without 
any  unpleasant  smell  being  evident. 

WATER  MEADOWS.  Meadows  on 
low  flat  grounds,  capable  of  being  kept 
in  a  state  of  fertility  by  being  overflown 
with  water  from  some  adjoining  river  or 
stream.  The  principal  season  at  which 
this  operation  is  performed  is  during 
winter,  when  the  water  is  allowed  to  re- 
main stagnant  on  the  surface  for  some 
weeks  ;  but  meadows  which  can  be  wa- 
tered are  occasionally  overflown  during 
summer,  especially  after  a  crop  of  hay 
has  been  taken.  *The  manner  in  which 
water  so  applied  to  grass  lands  is  found 
beneficial  has  never  been  satisfactorily 
explained.  By  some  it  is  attributed  to 
the  warmth  retained  in,  or  communicated 
to,  the  soil,  by  the  water  during  winter; 
by  others  to  its  effect  in  destroying  in- 
sects, worms,  &c. ;  and  by  some  to  the 
particles  of  manure  deposited  on  the  sur- 
face of  the  soil.  During  summer  the  ef- 
fect is  more  readily  accounted  for,  a  sup- 
ply of  moisture  being  advantageous  to 
all  plants  at  that  dry  season.  {See  Irri- 
gation.) 

WATER  OF  CRYSTALLIZATION. 
Some  crystallized  salts  contain  more  or 
less  water,  which,  as  it  bears  a  definite 
proportion  to  the  other  components  of 
the  salt,  may  be  considered  as  one  of  its 
essential  constituents.  Crystallized  sul- 
phate of  lime,  for  instance,  is  a  com- 
pound of  68  of  dry  sulphate  and  18  wa- 
ter, or  of  1  equivalent  of  anhydrous  salt 
and  2  equivalents  of  water  ;  1  equivalent 
of  crystallized  sulphate  of  magnesia=123, 
contains  7  of  water  =  63  ;  and  an  equiva- 
lent of  crystallized  sulphate  of  soda=162, 
contains  10  of  water=90;  the  equivalent 
of  water  being  9.  But  it  does  not  neces- 
sarily follow  that  a  salt  in  crystals  con- 
tains water,  there  being  many  crystals 
which  are  anhydrous,  such  as  nitre,  sul- 
phate of  potash,  &c. 

WATER  TABLE.  In  architecture,  a 
projection  or  horizontal  set-off  in  a  wall, 
so  placed  as  to  throw  off  the  water  from 
the  building. 

WATER' WAYS.  Strong  pieces  of 
wood  extending  round  the  ship,  at  the 
junction  of  the  decks  with  the  sides,  to 
carry  off  the  water. 

WATER  WHEEL.  In  hydraulics, 
an  engine  for  raising  water  in  large  quan- 


672 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[WAT 


tities.  Also  a  wheel  turned  by  the  force 
of  running  water.  The  kinds  most 
known  are  :  the  undershot  wheel,  and  the 
overshot  wheel. 

The  force  on  an  overshot  water-wheel 
is  that  of  the  weight  of  the  water  falling 
on  it,  the  power  being  to  the  effect  as 
three  to  two.  The  force~on  an  undershot- 
wheel  is  the  velocity  of  the  body  of  wa- 
ter, the  power  being  to  the  effect  as  three 
to  one,  or  half  the  other. 

The  particles  of  fluids  are  found  to 
flow  over  or  amongst  each  other  with 
less  friction  than  over  solid  substances  ; 
and  as  each  particle  has  weight,  it  fol- 
lows that  no  quantity  of  homogeneous 
fluid  can  be  in  a  state  of  rest,  unless 
every  part  of  its  surface  is  on  a  level. 
As  the  particles  of  all  liquids  are  heavy, 
any  vessel  containing  a  liquid  will  be 
carried  towards  the  earth  by  the  two- 
fold motion,  with  a  power  equivalent 
to  the  weight  it  contains,  and,  if  the 
quantity  of  the  fluid  be  doubled,  tripled, 
&c,  the  influence  will  be  doubled,  tri- 
pled, &c. 

The  pressure  of  fluids  is,  therefore, 
simply  as  their  heights — a  circumstance 
of  great  importance  in  the  construction 
of  pumps  and  engines  for  raising  water. 
As  atoms  of  liquids  fall  independently, 
if  a  hole  be  made  in  the  bottom  of  the 
vessel  the  liquid  will  flow  out,  those 
particles  directly  over  the  hole  being 
discharged  first.  Their  motion  causes 
a  momentary  vacuum,  into  which  the 
particles  tend  to  flow  from  all  direc- 
tions, and  thus  the  whole  mass  of  the 
water,  and  not  merely  the  perpendicu- 
lar column  above  the  orifice,  is  set  in 
motion. 

"When  water  flows  in  a  current,  as  in 
rivers,  it  is  in  consequence  of  the  incli- 
nation of  the  channel,  and  its  motion  is 
referable  to  that  of  solids  descending  an 
inclined  plane  ;  but,  from  want  of  cohe- 
sion among  its  particles,  the  motions  are 
more  irregular  than  those  of  solids,  and 
involve  difficult  questions.  The  friction 
between  a  solid  and  the  surface  on  which 
it  moves  can  be  accurately  ascertained ; 
but  this  is  not  the  case  with  liquids,  one 
part  of  which  may  be  moving  rapidly 
and  another  slowly,  while  another  is  sta- 
tionary. 

In  rivers  and  pipes,  the  water  in  the 
eentre  moves  with  greater  rapidity  than 
at  the  rubbing  sides,  so  that  a  pipe  does 
not  discharge  as  much^  water  in  a  given 
time,  in  proportion  to  its  magnitude,  as  j 
theoretical  calculations  would  lead  us  to  | 
suppose.     As  water,  in  descending,  fol-  I 


lows  the  same  laws  as  other  falling  bo- 
dies, its  motion  is  accelerated  ;  in  rivers, 
therefore,  the  velocity  and  quantity  dis- 
charged at  different  depths  would" be  as 
the  square  roots  of  those  depths,  did  not 
the  friction  against  the  bottom  check  the 
rapidity  of  the  flow. 

The  same  law  applies  to  the  spouting 
of  water  through  jets  or  adjutages. 

One  of  the  most  useful  forms  of  water, 
which  is  that  of  French  invention,  called 
the  turbine,  is  a  species  of  hydraulic  en- 
gine, employed  to  a  considerable  extent 
in  modern  times,  as  a  prime  mover  for 
machinery.  It  is  considered  to  be  pre- 
ferable to  ordinary  water-wheels,  in  situ- 
ations where  the  height  of  the  fall  is 
great  and  the  quantity  of  water  not  very 
considerable.  The  annexed  cut  repre- 
sents an  example  of  a  turbine,  or  hori- 
zontal water-wheel.  The  water  is  intro- 
duced into  a  close  cast-iron  vessel  a,  by 
the  pipe  b,  connecting  it  with  the  reser- 
voir. Here,  by  virtue  of  its  pressure,  it 
tends  to  escape  by  any  aperture  which 
may  be  presented ;  but  the  only  aper- 
tures consist  of  a  series  of  curved  float 


boards  //,  fixed  to  a  horizontal  plate  <7, 
mounted  upon  a  central  axis  h,  which 
passes  upwards  through  a  tube  connect- 
ing the  upper  and  lower  covers,  c  and  d, 
of  the  vessel  a.  Another  series  of  curv- 
ed plates  e  e,  is  fixed  to  the  upper  sur- 
face of  the  disk  d,  to  give  a  determinate 
direction  to  the  water  before  flowing  out 
at  the  float  boards,  and  the  curves  of 
these  various  parts  are  so  adjusted  as  to 


WAV] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


673 


render  the  reactive  force  of  the  water 
available  to  the  utmost  extent  in  produc- 
ing a  circular  motion.  The  machinery 
to  be  impelled  is  connected  with  the 
axis  h. 

WATER-PROOF  CLOTH.  {See  Ca- 
outchouc.) 

A  patent  was  obtained,  in  1830,  by  Mr. 
Thomas  Hancock,  for  rendering  textile 
fabrics  impervious  to  water  and  air,  by 
spreading  the  liquid  juice  of  the  caout- 
chouc tree  upon  the  surfaces  of  the 
goods,  and  then  exposing  them  to  the  air 
to  dry.  It  does  not  appear  that  this  pro- 
ject has  been  realized  in  our  manufac- 
tures. 

Mr.  William  S.  Potter  proposes,  in  his 
patent  of  1835,  to  render  fabrics  water- 
proof by  imbuing  them  with  a  solution 
of  isingglass,  alum,  and  soap,  by  means 
of  a  brush  applied  to  the  wrong  side  of 
the  cloth,  distended  upon  a  table.  After 
it  is  dry,  it  must  be  brushed  on  the 
wrong  side,  against  the  grain.  Then  the 
brush  is  to  be  dipped  in  clean  water,  and 
passed  lightly  over  the  cloth.  The  gloss 
caused  by  the  above  application  can  be 
taken  off  by  brushing  the  goods  when 
they  are  dry.  Cloth  so  prepared  is  said 
to  be  impervious  to  water,  but  not  to  air. 

Mr.  Sievier's  plan  of  rendering  cloth 
water-proof,  for  which  he  obtained  a  pa- 
tent in  1835,  consists  in  spreading  over 
it,  with  a  brush,  a  solution  of  India-rub- 
ber in  spirits  of  turpentine,  at  one  or 
more  applications,  and  then  applying  a 
similar  solution  mixed  with  acetate  of 
lead,  litharge,  sulphate  of  zinc,  gum  mas- 
tic, or  other  drying  material.  He  next 
takes  wool,  or  other  textile  material,  cut 
into  proper  lengths,  and  spreads  it  upon 
the  surface  of  the  fabric  varnished  in  this 
manner,  for  the  purpose  of  forming  the 
nap  or  pile.  He  then  presses  the  cloth 
by  means  of  rollers,  or  brushes,  so  as  to 
fix  the  nap  firmly  to  its  surface. 

WAVES.  Undulations  of  fluids  pro- 
duced by  displacements  of  the  particles 
at  some  distance,  and  the  subsequent  ef- 
fort of  these  to  regain  their  equilibrium, 
or  place  themselves  upon  the  same  fluid 
level.  The  waves  of  the  ocean  produced 
by  the  action  of  the  winds  never  attain 
the  height  which  it  is  commonly  esti- 
mated they  do.  Dr.  Scoresby,  'in  his 
estimation  of  the  waves  of  the  Atlantic 
Ocean,  found  the  average  wave  to  be  15 
feet  above  the  level  of  the  water,  suppos- 
ing it  to  be  a  smooth  plane :  ana  the 
mean  highest  waves,  not  including  the 
broken  or  acuminated  crests,  to  be  43 
feet  above  the  hollow,  or  trough  of  the 
29 


sea,  produced  by  the  walling  up  of  the 
I  wave.  It  is  only  the  upper  stratum  of 
j  the  water  which  is  thus  agitated  (from 
15  to  20  feet  from  the  surface),  and  the 
wave  is  not  carried  forward,  but  rises  up 
and  down,  and  thus  displaces  a  fresh 
body  of  water  in  advance,  compelling  it 
to  rise  up,  and  become  a  wave  in  turn. 

There  are  waves  in  the  atmosphere  as 
well  as  in  the  ocean,  and  the  upper  re- 
gions of  the  air  have  their  currents, 
tides,  and  waves,  just  as  the  oceans  of 
water.  It  is  the  elevation  and  depres- 
sion of  these  great  atmospheric  waves 
which  produce  a  corresponding  move- 
ment in  the  mercury  of  the  barometer 
tube. 

This  physical  phenomenon  of  undula- 
tion is  not  confined  to  fluids  and  gases  : 
it  appears  to  be  a  property  of  the  ether 
which  fills  space,  agitations  of  which 
produce  such  interesting  effects.  Heat 
and  electricity,  it  is  presumed,  are  par- 
ticular forms  of  undulation  of  the  ether, 
and  light  is  now  generally  admitted  to 
be  waves  of  ether  ;  the  nature  and  color 
of  the  light  being  produced  by  varieties 
in  the  undulation.  To  produce  an  ordi- 
nary ray  of  white  light,  it  is  not  merely 
necessary  that  the  ether  should  be  agi- 
tated by  horizontal  waves,  like  those  of 
the  ocean,  but  that  it  should  also  have 
waves  vibrating  vertically,  or  from  side 
to  side  :  and  these  two  "kinds  of  waves 
are  bound  together  in  the  ordinary  ray 
of  sunlight.  These  two  rays  may  be 
separated  by  passing  the  sunlight  through 
certain  substances,  as  a  clear  crystal  of 
Iceland  spar,  doubly  refracting  spar,  a 
variety  or  carbonate  of  lime.  By  turning 
the  crystal  round  in  the  hand  above  any 
object,  such  as  a  single  letter  on  a  white 
surface,  two  images  of  this  letter  will  be 
perceived,  one  of  which  remains  station- 
ary, or  nearly  so,  while  the  other  travels 
round  it  in  a  circle ;  the  latter  is  called 
the  extraordinary,  the  former  the  ordi- 
nary ray.  The  phenomenon  is  produced 
by  the  refractive  power  of  the  spar, 
which  thus  resolves  the  luminous  undu- 
lations into  two  colorless  series  at  right 
angles  to  each  other ;  when  combined, 
constituting  common  light,  and  when 
separated,  producing  polarized  light,  so 
called,  because  they  assume  new  and  pe- 
culiar properties  with  regard  to  each 
other,  and  different  refracting  or  reflect- 
ing media. 

Many  minerals  polarize  light,  as  agates 
and  tourmalines.  Light  thus  altered 
may  also  be  obtained  by  reflection  from 
surfaces,  such  as  glass  ;  and  it  was  from 


674 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[wax 


this  source  it  was  first  discovered  by 
Malus.  By  more  complicated  methods, 
the  ray  of  colorless  light  may  be  so  much 
refracted  as  to  be  broken  up  into  its 
colored  rays,  and  then  acting  in  a  man- 
ner similar  to  the  colorless  ray,  produces 
the  phenomenon  of  colored  polarization. 
This  subject  cannot  be  entered  into  mi- 
nutely in  this  treatise.  Polarized  light 
is  now  made  use  of  in  the  arts  as  a  test 
for  the  purity  of  substances.  It  is  found 
that  liquids  have  the  property  of  polariz- 
ing light  similar  to  crystals,  and  not  only 
is  the  amount  of  separation  of  the  two 
rays  constant  at  all  times  for  the  same 
substance,  but  even  the  direction  is  also 
permanent  and  unvarying;  thus  some 
substances  turn  the  polarized  ray  to  the 
right,  and  others  to  the  left.  It  is  only 
necessary,  therefore,  to  know  what  the 
amount  and  direction  of  the  deviation 
of  the  ray  is,  and  then  by  looking  into 
the  tables  made  for  that  purpose,  the  ex- 
act substance  will  be  found  opposite  to 
the  figures  in  the  table.  Solutions  of 
sugar,  camphor,  and  many  other  organic 
liquids,  naturally  develop  the  phenom- 
enon of  circular  polarization, — that  is, 
make  the  ray  revolve  round.  Oil  of  tur- 
pentine makes  the  ray  rotate  to  the 
right;  so  also  does  naphtha  and  oil  of 
anise,  syrup  of  grape  sugar  and  grape 
juice ;  while  oils  of  citron  and  berga- 
mot,  solution  of  cane  sugar,  and  tartaric 
acid,  make  the  ray  rotate  to  the  left. 
Polarization  is  often  made  a  useful  test  of 
the  presence  and  purity  of  essential  oils 
and  volatile  liquids.  The  instrument 
with  which  these  experiments  are  made 
is  called  a  polari- 
scope ;  an  illus- 
tration of  which 
is  given.  It  con- 
sists of  a  tube  of 
brass  one  inch 
broad,  and  eight  inches  long,  A,  B,  into 
which  the  fluid  to  be  examined  is  placed. 
The  tube  is  closed  at  the  lower  end  by  a 
plate  of  glass.  At  one  extremity  of  this 
tube  is  placed  a  bundle  of  plates  of  win- 
dow-glass N'  fixed  so  as  to  admit  of  ready 
motion,  and  supported  by  a  screw  in  its 
place.  These  plates  of  glass  receive  the 
ray  of  light,  polarize  it,  and  transmit  it 
through  the  tube  containing  the  liquid. 
At  the  other  end  of  the  tube  is  placed 
the  eye- piece  M,  consisting  of  a  single 
image  prism,  or  Nicholl's  prism,  which 
is  a  crystal  of  refracting  spar  sawed 
down  the  middle,  and  soldered  together 
by  Canada  balsam.  A  bundle  of  thin 
glass  plates  may  be  used  instead  of  this, 


if  they  are  capable  of  being  placed  at  any 
azimuth. 

WAX.  This  is  a  common  vegetable 
product  forming  the  varnish  which  coats 
the  leaves  of  certain  plants  and  trees. 
It  is  also  found  upon  some  berries,  as  of 
the  Myrka  cerifera  ;  and  it  is  an  ingre- 
dient of  the  pollen  of  flowers.  It  was 
long  supposed  that  bees  merely  collected 
the  wax  thus  ready  formed  in  plants* 
bat  Huber  found  that  though  excluded 
from  all  food  except  sugar,  they  still 
formed  wax;  and  accordingly  it  has  been 
found  that  the  elementary  composition 
of  bees'  wax  and  vegetable  wax  is  slightly 
different.  Bees'  wax  is  prepared  by 
draining  and  washing  the  honeycomb, 
which  is  then  melted  in  boiling  water, 
strained,  and  cast  into  cakes.  English 
and  foreign  wax  are  found  in  the  market ; 
the  latter  being  chiefly  imported  from 
the  Baltic,  the  Levant,  and  the  coast  of 
Barbary.  Fresh  wax  has  a  peculiar 
honey-like  odor :  its  specific  gravity  is 
•96.  At  about  150°  it  fuses,  and  at  a 
high  temperature  volatilizes,  and  burns 
with  a  bright  white  flame.  It  is  bleach- 
ed by  being  exposed  in  thin  slices  or 
ribbons  to  fight,  air,  and  moisture,  or 
more  rapidly  by  the  action  of  chlorine ; 
but  in  the  latter  case  it  does  not  answer 
for  the  manufacture  of  candles,  which  is 
one  of  its  principal  applications.  Wax 
candles  are  made  by  suspending  the 
wicks  upon  a  hoop  over  the  caldron  of 
melted  wax,  which  is  successively  pour- 
ed over  them  from  a  ladle  till  they  have 
acquired  the  proper  size,  so  that  the  can- 
dle consists  of  a  series  of  layers  of  wax ; 
the  upper  end  is  then  shaped,  and  the 
lower  cut  off.  Attempts  have  been  made 
to  cast  wax  candles  in  moulds,  but  when 
thus  made  they  burn  irregularly.  Bleach- 
ed or  white  wax  is  generally  adulterated 
with  more  or  less  spermaceti,  and  sold  at 
different  prices  accordingly  ;  in  this  case 
it  has  not  the  peculiar  lustre  of  pure 
wax,  and  is  softer  and  more  fusible.  It 
is  also  largely  adulterated  with  stearine 
or  stearic  acid,  which  is  detected  by  the 
odor  or  fat  of  tallow  which  it  evolves 
when  highly  heated,  and  by  its  crumbly 
texture ;  it  may  also  be  separated  to  a 
certain  extent  by  ether  or  alcohol.  Wax 
is  insoluble  in  water,  and  scarcely  acted 
upon  by  the  acids,  so  that  it  forms  a 
good  lute  or  cement :  boiling  alcohol  and 
ether  act  partially  upon  it,  and  deposit 
the  portion  which  they  had  dissolved, 
on  cooling.  Some  varieties  of  vegetable 
wax  appear  to  contain  two  distinct  prin- 
ciples, which  Dr.  John  has  termed  cerin 


wed] 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


675 


and  mi/ricm ;  the  former  soluble,  and  the 
latter  insoluble,  in  alcohol.  Heated  with 
the  fixed  alkalies,  wax  forms  a  difficultly 
soluble  soap. 

WEATHER-BOARDING.  In  archi- 
tecture, feather-edged  boarding  nailed 
upright,  whose  boards  lap  over  each 
other,  so  as  to  prevent  the  rain,  &c, 
from  penetrating  them. 

WEATHER  GLASS.  A  name  com- 
monly given  to  the  barometer ;  but  some- 
times also  applied  to  other  instruments 
for  ascertaining  the  state  of  the  atmos- 
phere, or  measuring  atmospheric  changes. 
It  is  thus  applied  to  the  thermometer,  the 
hygrometer,  &c. 

W  E  A VING.  The  art  of  forming  cloth 
in  a  loom  by  the  union  or  intertexture 
of  threads.  The  art  of  weaving  is  of 
great  antiquity  :  it  has  been  practised  in 
all  ages  and  in  all  countries  ■  but  it  would 
be  impossible  within  our  limits  to  give 
even  a  sketch  of  its  history,  progress, 
and  successive  improvements  down  to 
its  present  perfect  state.  We  had  in- 
tended to  present  the  reader  with  a 
sketch  of  the  various  improvements  that 
have  been  made  in  the  loom  from  its 
simplest  construction,  down  to  the  elabo- 
rate invention  of  Jacquard ;  but  it  was 
found  that  this  could  not  be  effected 
without  the  introduction  of  numerous 
diagrams  and  details,  which  would  have 
been  foreign  to  the  purpose  of  the  work. 

The  loom  is  described  in  its  proper 
place  in  this  volume.  The  manner  in 
which  the  threads  are  spun,  for  weaving, 
is  described  under  the  heads  COTTON 
MANUFACTURE,  FLAX,  SILK  MAN- 
UFACTURE, WOOL.  The  thread  for 
the  warp,  is  first  wound  or  spooled, 
which  operation  consists  in  winding  it 
upon  spools  or  bobbins.  The  next  opera- 
tion is  that  of  warping,  the  object  of 
which  is,  so  to  arrange  all  the  longitudi- 
nal threads,  which  are  intended  to  form 
the  chain  or  warp  of  the  web,  as  to  form 
when  spread  out,  a  chain  of  parallel 
threads.  In  forming  the  warp,  a  suffi- 
cient number  of  bobbins,  filled  with  yarn, 
must  be  taken,  to  furnish  the  number  of 
threads  of  the  required  length  of  the 
piece  of  cloth  intended  to  be  woven. 
These  threads  are  wound  on  a  large  reel, 
from  the  bobbin.  This  contrivance  is 
termed  the  warping  machine.  The  next 
operation  is  that  of  beaming,  which  con- 
sists in  winding  the  warp  upon  the  yarn 
beam  of  the  loom.  This  is  performed  by 
the  weaver,  who  receives  his  warp  from 
the  warping  machine,  in  a  bunoh  or  ball. 
The  next  thing  to  be  done,  is  the  draw- 


ing or  entering,  which  consists  in  taking 
the  threads,  ot'  the  warp  in  proper  order, 
and  passing  them  through  the  beadles  and 
reed,  two  threads  of  the  warp  being  taken 
through  every  interval  of  the  reed. 

These  operations  being  finished,  the 
cords  or  mounting  which  moves  the 
headles  is  applied,  another  reed  is  placed 
in  the  lay.  The  warp  is  then  divided  into 
small  portions,  which  are  tied  to  a  shaft 
connected  by  cords  to  the  cloth  beam. 

If  the  loom  is  a  power  loom,  the 
warp  is  dressed  by  what  is  termed  the 
dressing  machine  ;  "but  in  hand  looms,  it 
is  dressed,  a  portion  at  a  time.  Dressing 
consists  in  sizing  the  yarn  with  a  muci- 
lage of  vegetable  matter,  boiled  in  water. 
Wheat  flour,  and  sometimes  potatoes,  are 
the  substances  commonly  employed  for 
cotton  and  linen.  The  effect  of  the  sizing 
process,  is  to  give  sufficient  strength  and 
tenacity  to  the  yarn,  to  enable  it  to  bear 
the  operation  of  weaving.  It  also,  by 
laying  smoothly  all  the  ends  of  the  fibres, 
which  compose  the  raw  material,  from 
which  the  yarn  is  spun,  tends  to  dimin- 
ish friction  during  the  operation,  and  to 
render  the  fabric  smooth  and  glossy. 
After  dressing,  the  yarn  requires  to  be 
dried.  Some  specimens  of  linen  fab- 
rics obtained  from  Egyptian  mummies 
are  of  a  fineness  rarely  equalled  by  weav- 
ers of  modern  times,  though  it  is  tolera- 
bly certain,  that  the  mechanism  employed 
in  its  manufacture,  could  not  have  been 
nearly  as  perfect  as  that  employed  at  the 
present  time.  Among  the  different  de- 
scriptions of  weaving  we  may  mention 
chiefly  plain  weaving,  tweeling,  weaving 
double  cloth,  weaving  crossed  warps  or 
nets,  fancy  weaving,  figured  weaving,  car- 
peting, and  piled  fabrics,  many  of  which 
are  subdivided  into  different  materials.  In 
addition  to  vegetable  and  animal  substan- 
ces, may  be  mentioned  metallic  tissues  or 
threads  formed  of  metal,  and  glass.  For 
more  information,  see  LOOM. 

WEDGE,  in  mechanics,  is  one  of  the 
five  simple  engines  or  mechanical  powers, 
and  is  used  sometimes  for  raising  oodies, 
but  more  frequently  for  dividing  or  split- 
ing  them.  In  the  former  case,  if  we 
suppose  the  wedge  to  be  urged  by  pres- 
sure, the  action  of  the  wedge  is  pre- 
cisely the  same  as  that  of  the  inclined 
plane  ;  for  it  is  evidently  the  same,  in 
point  of  mechanical  advantage,  whether 
the  wedge  be  pushed  under  the  load,  or 
the  load  be  drawn  over  the  plane.  The 
power  is  therefore  to  the  force  to  be 
overcome  as  the  tangent  of  the  angle  oi 
the  penetrating  sides  to  the  radius,  leav- 


676 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[WHA 


ing  the  friction  out  of  consideration : 
hence  the  thinner  the  wedge  the  greater 
is  its  effect.  But  when  the  wedge,  as  is 
generally  the  case,  is  driven  forward  by 
percussion,  its  power  cannot  be  esti- 
mated with  any  degree  of  accuracy. 
The  percussive  tremor  excited  by  the 
blow  destroys  for  an  instant  the  friction 
at  the  sides,  and  augments  prodigiously 
the  penetrating  effect.  Besides,  when 
the  wedge  is  used  in  rending  wood  or 
other  substances,  the  parts  of  the  block 
are  generally  separated  to  a  considerable 
distance  before  the  edge  of  the  wedge  , 
in  which  case  it  acts  besides  as  a  lever, 
the  power  being  applied  at  the  end  of 
the  block  or  acting  part  of  the  wedge, 
and  the  resistance  being  at  the  point 
where  the  fibres  begin  to  separate. 

All  the  various  kinds  of  cutting  and 
piercing  tools,  as  axes,  knives,  scissors, 
chisels,  &c,  nails,  pins,  awls,  &c,  are 
modifications  of  the  wedge.  The  angle 
in  these  cases  is  more  or  less  acute,  ac- 
cording to  the  purpose  to  which  it  is 
applied.  The  mechanical  advantage  is 
increased  by  diminishing  the  angle  of 
the  wedge  ;  but  the  strength  of  the  tool 
is  thereby  also  diminished.  In  tools  for 
cutting  wood  the  angle  is  generally  about 
80° ;  for  iron  it  is  from  50°  to  60° ;  and 
for  brass  from  80°  to  90°.  In  general, 
the  softer  the  substance  to  be  divided 
is,  the  more  acute  may  the  wedge  be 
constructed. 

WEFT  is  the  name  of  the  yarns  or 
threads  which  run  from  selvage  to  sel- 
vage in  a  web. 

"WELD  is  an  annual  herbaceous  plant, 
which  grows  all  over  Europe,  called  by 
botanists  Reseda  luteola.  The  stems  and 
the  leaves  dye  yellow ;  and  among  the 
dyes  of  organic  nature,  they  rank  next 
to  the  Persian  berry  for  the  beauty  and 
fastness  of  color.  The  whole  plant  is 
cropped  when  in  seed,  at  which  period 
its  dyeing  power  is  greatest;  and  after 
being  simply  dried,  it  is  brought  into  the 
market. 

Chevreul  has  discovered  a  yellow  co- 
loring principle  in  weld,  which  he  has 
called  luteolvnt.  It  may  be  sublimed, 
and  thus  obtained  in  long  needle-form, 
transparent,  yellow  crystals.  Luteoline 
is  but  sparingly  soluble  in  water ;  but  it 
nevertheless  dyes  alumed  silk  and  wool 
of  a  fine  jonquil  color.  It  is  soluble  in 
alcohol  and  etner ;  it  combines  with  acids, 
and  especially  with  bases. 

When  weld  is  to  be  employed  in  the 
dye-bath,  it  should  be  bailed  for  three 


quarters  of  an  hour;  after  which  the 
exhausted  plan£  is  taken  out,  because  it 
occupies  too  much  room.  The  decoction 
is  rapidly  decomposed  in  the  air,  and 
ought  therefore  to  be  made  only  when  it 
is  wanted. 

WELDING    is    the    property  which 

Eieces  of  wrought  iron  possess,  when 
eated  to  whiteness,  of  uniting  intimate- 
ly and  permanently  under  the  hammer, 
into  one  body,  without  any  appearance 
of  junction.  The  welding  temperature 
is  usually  estimated  at  from  60°  to  90°  of 
Wedgewood.  When  a  skilful  blacksmith 
is  about  to  perform  the  welding  opera- 
tion, he  watches  minutely  the  effect  of 
the  heat  in  his  forge-fire  upon  the  two 
iron  bars  :  and  if  he  perceives  them  be- 
ginning to  burn,  he  pulls  them  out,  rolls 
them  in  sand,  which  forms  a  glassy  sili- 
cate of  iron  upon  the  surface,  so  as  to 
f)revent  further  oxidizement ;  and  then 
aying  the  one  properly  upon  the  other, 
he  incorporates  them  by  his  right-hand 
hammer,  being  assisted  by  another  work- 
man, who  strikes  the  metal  at  the  same 
time  with  a  heavy  forge-hammer. 

Platinum  is  not  susceptible  of  being 
welded,  although  usually  said  to  be. 

WHALEBONE  is  the  name  of  the 
horny  lauiinae,  consisting  of  fibres  laid 
lengthwise,  found  in  the  mouth  of  the 
whale,  which,  by  the  fringes  upon  their 
edges,  enable  the  animal  to  allow  the 
water  to  flow  out,  as  through  rows  of 
teeth  (which  it  wants),  from  between  ita 
capacious  jaws,  but  to  catch  and  detain 
the  minute  creatures  upon  which  it 
feeds.  The  fibres  of  whalebone  have 
little  lateral  cohesion,  as  they  are  not 
transversely  decussated,  and  may,  there- 
fore, be  readily  detached  in  the  form  of 
long  filaments  or  bristles.  The  blades, 
or  scythe-shaped  plates,  are  externally 
compact,  smooth,  and  susceptible  of  a 
good  polish.  They  are  connected,  in  a 
parallel  series,  by  what  is  called*  the 
gum  of  the  animal,  and  are  arranged 
along  each  side  of  its  mouth,  to  the 
number  of  about  800.  The  length  of 
the  longest  blade,  which  is  usually  found 
near  the  middle  of  the  series,  is  the 
gauge  adopted  by  the  fishermen  to  desig- 
nate the  size  of  the  fish.  The  greatest 
length  hitherto  known  has  been  15  feet, 
but  it  rarely  exceeds  12  or  18.  The 
breadth,  at  the  root  end,  is  from  10  to  12 
inches ;  and  the  average  thickness,  from 
four  to  five-tenths  of  an  inch.  The  se- 
ries, viewed  altogether  in  the  mouth  of 
the  whale,  resemble,  in  general  form,  the 


tthe] 


CYCLOPEDIA    OF   THE   USEFUL   ARTS. 


677 


roof  of  a  house.  They  are  cleaned  and 
softened  before  cutting,  by  boiling  for 
two  hours  in  a  long  copper. 

From  its  flexibility,  strength,  elasticity, 
and  lightness,  whalebone  is  employed 
for  many  purposes  :  for  ribs  to  umbrellas 
or  parasols  ;  for  stiffening  stays  ;  for  the 
framework  of  hats,  &e.  When  heated 
by  steam,  or  a  sand-bath,  it  softens,  and 
may  be  bent  or  moulded,  like  horn,  into 
various  shapes,  which  it  retains,  if  cool- 
ed under  compression.  In  this  way,  snuff- 
boxes, and  knobs  of  walking-sticks,  may 
be  made  from  the  thicker  parts  of  the 
blade.  The  surface  is  polished  at  first 
with  ground  pumice-stone,  felt,  and  wa- 
ter ;  and  finished  with  dry  quicklime, 
spontaneously  slaked,  and  sifted. 

WHEEL  WORK,  in  machinery,  con- 
sists of  a  combination  of  wheels  commu- 
nicating motion  to  one  another.  Such 
combinations  may  be  formed  in  various 
ways  ;  but  they  are  generally  reducible 
to  the  principle  of  the  wheel  and  axle, 
though  the  wheel,  which  turns  the  other, 
is  not  usually  on  the  same  axis  with  it. 
The  motion  in  such  cases  is  communi- 
cated from  the  one  wheel  to  the  other, 
either  by  belts  or  straps  passing  over  the 
circumferences  of  both,  or  by  teeth  cut 
in  those  circumferences,  and  working  in 
one  another.  In  either  of  these  ways 
the  velocities  of  points  in  their  circum- 
ferences are  equal ;  and  consequently 
their  angular  velocities,  or  the  number  of 
revolutions  which  they  make  in  the 
same  time,  are  inversely  as  their  radii. 
When  one  wheel  drives  another  by  teeth, 
they  necessarily  turn  in  opposite  direc- 
tions ;  if  united  by  a  cord  or  belt,  they 
will  turn  in  the  same  direction,  if  the 
belt  does  not  cross  itself  between  the 
two  wheels  ;  but  if  the  belt  crosses  itself, 
they  will  turn  in  opposite  directions. 
The  chief  advantage  of  transmitting  mo- 
tion by  cords  or  belts  is,  that  the  wheels 
may  be  placed  at  any  convenient  dis- 
tance from  each  other,  and  be  made  to 
turn  either  in  the  same  or  in  opposite 
directions. 

Wheels  may  act  on  one  another,  so  as 
to  communicate  motion  in  various  ways. 
When  the  resistance  of  the  work  is  not 
great,  the  object  may  be  accomplished 
by  the  mere  friction  of  their  circumfer- 
ences. In  order  to  increase  the  friction, 
the  surfaces  of  the  rims  are  faced  with 
buff  leather  (caoutchouc  might  answer 
the  purpose  better),  or  wood  cut  against 
the  grain,  and  pressed  together  with  a 
certain  degree  of  force.  This  method  is 
sometimes  used  in  spinning  machinery, 


and  has  even  been  applied  successfully 
to  the  saw-mill ;  but  it  is  seldom  adopted 
in  works  on  a  great  scale.  Motion  commu- 
nicated in  this  manner  proceeds  smooth- 
ly and  evenly,  and  is  accompanied  with 
little  noise. 

When  motion  is  to  be  transmitted 
through  a  train  of  wheel  work,  toothed 
wheels  are  generally  employed.  It  is 
usual  to  call  a  small  wheel  acted  on  by  a 
large  one  opinion,  and  its  teeth  the  leaves 


of  the  pinion.  Wheels  and  pinions  are 
combined  variously,  sometimes  as  in  the 
annexed  cut ;  at  other  times,  the  axle  of 
the  wheel,  which  bears  the  power,  is  a 
pinion,  which  drives  the  second  wheel. 
The  axle  of  this  wheel  carries  a  pinion, 
which  drives  the  third  wheel.  When 
motion  is  communicated  in  this  manner, 
the  angular  velocity  of  the  first  wheel  is 
to  that  of  the  last  pinion  as  the  product 
formed  by  multiplying  together  the  radii 
of  all  the  wheels  to  the  product  formed 
by  multiplying  together  the  radii  of  all 
the  pinions.  Consequently,  if  R,  R',  R", 
&c,  denote  respectively  the  radii  of  the 
wheels,  and  f,  r'  r",  &c.,  the  radii  of  the 
pinions,  we  shall  have,  by  the  principle 
of  virtual  velocities  p  (R  XR'  X  R'',  &c.) 
=  w  (r  X  r'  X  r",  &c.)  As  the  size  of  the 
teeth  of  any  wheel  and  the  pinion  into 
which  it  works  must  be  equal,  we  may 
substitute  for  the  radii  the  number  of 
teeth  in  the  wheels  and  pinions  respec- 
tively. 

Toothed  wheels,  as  distinguished  by 
the  position  of  the  teeth  relatively  to  the 
axis,  are  of  three  kinds  :  spur  wheels, 
crown  wheels,  and  bevelled  wheels.  When 
the  teeth  are  raised  upon  the  edcre  of  the 
wheel,  or  are  perpendicular  to  the  axis  (as 
in  the  above  figured,  the  wheel  is  a  spur 
wheel  ;  when  they  are  raised  parallel  to 
the  axis,  or  perpendicular  to  the  plane 
of  a  wheel,  it  is  a  crown  wheel ;  and 
when  they  are  raised  on  a  surface  inclined 
to  the  plane  of  the  wheel,  it  is  called  a 
bevelled  wheel.  The  combination  of  a 
crown  wheel  with  a  spur  wheel  as  pinion 


678 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


[WHE 


is  used  when  it  is  required  to  communi- 
cate motion  round  one  axis  to  another  at 
right  angles  to  it.  Two  bevelled  wheels 
arc  employed  to  transmit  motion  from 
one  axis  to  another  inclined  to  it  at  any 
proposed  angle.  Wheels  have  also  dif- 
ferent names,  according  to  their  mode  of 
action,  as  heart  wheel,  sun-and-planet 
wheel. 

Form  of  the  Teeth  of  Wheels.— In  the 
construction  of  machinery,  it  is  of  the 
utmost  importance  that  the  several  parts 
act  on  one  another  with  a  uniform  force, 
and  with  the  smallest  possible  amount  of 
friction.  When  wheels  act  by  teeth 
working  into  each  other,  every  point  of 
the  side  of  the  tooth  which  is  in  action 
comes  successively  into  contact  with  the 
tooth  of  the  pinion  as  the  wheel  turns 
round,  and  the  force  is  necessarily  ex- 
erted at  the  points  which  are  in  contact. 
Hence  the  lengths  and  positions  of  Ac 
(A  being  supposed  the  centre  of  the 
wheel  and  c  the  point)  and  B  c,  the  levers 
by  which  they  act,  are  constantly  chang- 
ing ;  and  in  order,  therefore,  that  the 
force  of  the  one  tooth  upon  the  other 
may  be  constant,  it  is  necessary  that  the 
line  drawn  perpendicular  to  the  surfaces 
of  both  teeth,  at  the  point  of  contact  c, 
always  intersect  the  line  A  B  of  the  cen- 
tres in  the  same  point.  There  are  many 
different  curves  according  to  which  the 
teeth  might  be  formed  so  as  to  answer 
this  condition  ;  but  that  which  has  been 
most  generally  adopted,  and  which  ap- 
pears the  most  convenient,  is  the  epicy- 
cloid generated  by  the  revolution  of  a 
circle  whose  radius  is  equal  to  half  the 
radius  of  the  pinion  on  the  circumference 
of  a  circle  equal  to  the  wheel.  This  was 
first  proposed  by  Eoemer,  the  celebrated 
Danish  astronomer.  The  evolute  of  the 
circle  was  proposed,  with  other  curves, 
by  Euler. 

When  the  teeth  are  constructed  ac- 
cording to  the  theoretical  rules,  the  ac- 
tion is  not  only  uniform,  but  there  is  little 
friction  ;  for  the  teeth  roll  on  one  another, 
and  neither  slide  nor  rub.  But  as  it 
is  impossible  to  attain  perfect  accuracy 
in  practice,  the  surfaces  of  the  teeth  will 
always  present  some  inequalities,  and 
there  will  consequently  be  some  friction. 
In  order,  therefore,  to  equalize  the  wear, 
it  is  necessary  that  every  leaf  of  the 
pinion  should  work  in  succession  through 
every  tooth  of  the  wheel,  and  not  always 
through  the  same  set  of  teeth  ;  and  hence 
the  number  of  teeth  in  a  wheel  and  in  a 
pinion  which  work  into  each  other  should 
be  prime  to  one  another.    This  precau- 


tion is  more  especially  necessary  in  mill- 
work,  and  where  considerable  force  is 
used. 

WHEELS  OF  CAEEIAGES.  Wheels 
consist  of  the  nave  or  stock,  in  the  cen- 
tre, the  spokes  which  are  radii,  and  the 
ring,  which  is  the  periphery  of  tho 
wheel.  When  a  wheel  is  to  be  made, 
the  workman  adapts  moulds  to  its  exact 
diameter.  Twelve  spokes  are  commonly 
assigned  to  the  larger  wheels  of  car- 
riages, and^ten  to  the  smaller  ones. 
The  working  and  finishing  of  the  several 
fellies,  to  form  the  periphery  of  a  wheel, 
consists,  after  it  has  been  roughly  chop- 
ped to  the  pattern,  in  forming  its  inside 
edge  somewhat  rounding,  and  getting  its 
outside  edge  perfectly  "circular,  and  to 
form  such  an  acute  angle,  that,  when  the 
wheel  is  adapted  to  the  axle-tree,  it  shall 
stand  square  and  solid  under  the  body  of 
the  carriage. 

The  strength  of  a  wheel  depends 
greatly  on  the  attention  paid  to  the  ar- 
rangement and  framing  of  the  spokes  ; 
in  common  wheels  they  are  framed  regu- 
larly and  equally  all  round  the  thickest 
part  of  the  nave,  the  tenons  of  the  spokes 
being  so  bevelled  as  to  stand,  with  re- 
ference to  the  horizontal  position  of  the 
nave,  about  three  inches  out  of  the  per- 
pendicular :  this  is  done  to  produce  what 
is  called  dishing.  But,  for  wheels  of 
strength,  such  as  the  wheels  of  road 
coaches,  the  framing  of  the  spokes  con- 
sists in  getting  every  other  one  perpen- 
dicular to  the  nave.  Hence  the  mortises 
to  receive  them  in  it  are  not  made  in  a 
parallel  line  round  it,  but  stand,  in  two 
different  parallels,  one  without  the  other, 
by  which  greater  solidity  is  given  to 
the  nave,  and  an  immense  addition  of 
strength. 

The  boxing^  of  a  wheel,  and  adapting 
the  axle-tree,  is  done  usually  by  the  coach 
or  tire-smith.  The  box  of  a  wheel  is  a 
hollow  conical  tube  of  iron,  furnished 
on  its  outside  with  two  or  three  square 
projections,  which  have  the  effect  of  giv- 
ing it  a  key  when  mortised  through  the 
nave  of  the  wheel.  Fatent  boxes  are  of 
a  different  construction,  and  owe  their 
safetv   to  four  bolts,    which  pass  eom- 

f)letely  through  the  nave  of  the  wheel, 
mving  a  square  shoulder  on  the  back  of 
the  nave,  with  screws  and  nuts  on  its 
front.  The  box  to  such  a  wheel  is  made, 
as  are  the  other  boxes  above  described, 
except  being  completely  closed  at  its 
outer  end,  with  a  solid  and  broad  cap 
of  iron,  of  sufficient  diameter  to  inclose 
completely  the  end  of  the  nave.     The 


CYCLOPEDIA    OF   THE    USEFUL   ARTS. 


679 


axle-tree,  too,  is  formed  to  fill  the  box, 
and  press  up  close  to  this  iron  cap. 

High  wheels  are,  in  bad  roads,  much 
preferable  to  low  ones,  except  where  the 
shape  of  any  inequality  of  the  road  per- 
mits the  low  wheel  to  roll,  while  the 
larger  wheel  can  bear  only  on  the  edges 
of  the  hole  over  which  it  is  to  pass.  But 
the  increased  expense  and  weight  of  very 
large  wheels  put  a  limit  to  their  size,  be- 
yond which  no  experienced  mechanic 
would  pass.  For,  although  the  mechan- 
ical power  of  a  wheel  in  surmounting  a 
given  obstacle  constantly  increases  with 
the  size  of  the  wheel,  it  does  not  in- 
crease directly  m  proportion  to  its  height. 
It  increases  but  little  more  than  in  pro- 
portion to  the  square  roots  of  the  diame- 
ter of  the  wheel ;  so  that  if  a  wheel  pass 
over  an  obstacle  with  a  given  power, 
though  it  may  be  made  to  pass  over  the 
same  obstacle  with  half  that  power  by 
increasing  the  diameter  of  the  wheel,  it 
is  not  to  be  expected  that  this  can  be 
done  by  making  the  wheel  twice  as  large  : 
for,  to 'effect  this  purpose,  awheel  offovr 
times  the  former  diameter  must  be  em- 
ployed. 

Mr.  Edgeworth  showed  that  practice 
agrees  with  theory.  A  wheel  of  seven 
inches  diameter,  loaded  with  twenty 
pounds,  required  eight  pounds  to  draw 
it  over  an  obstacle  of  one  quarter  of  an 
inch  high,  whereas,  when  a  wheel  of 
twenty-eight  inches  high  was  employed, 
four  pounds  drew  the  same  load  over 
the  same  obstacle.  And  when  the  line 
of  draught  was  horizontal,  the  larger 
wheel  required  four  pounds  four  ounces, 
the  smaller  nine  pounds. 

It  appears,  that  the  higher  the  wheels 
the  more  advantageous  is  the  draught : 
but,  in  fact,  the  expense,  the  strength, 
and  the  weight  of  wheels  must  be  taken 
into  account,  when  they  are  applied  to 
carriages ;  and  experience  has  deter- 
mined, that  the  best  height  of  wheels  is 
from  four  feet  six  inches  to  five  feet, 
for  coaches  and  carriages  that  move 
swiftly;  and  that,  for  heavy  carriages, 
wheels  seldom  are  found  useful  beyond 
the  diameter  of  six  feet. 

As  narrow  wheels  always  sink  into 
the  ground,  especially  when  the  heaviest 
part  of  the  load  lies  upon  them,  they 
must  be  considered  as  going  constantly 
up-hill,  even  on  level  ground.  And  their 
sides  must  sustain  a  great  deal  of  fric- 
tion by  rubbing  against  the  ruts  made 
by  others.  But  both  these  inconve- 
niences are  avoided  by  broad  wheels ; 
which,  instead  of  cutting  and  ploughing 


up  the  roads,  roll  them  smooth  and  har- 
den them,  as  experience  testifies,  in 
places  where  they  have  been  used,  espe- 
cially either  on  wettish  or  sandy  ground. 
The  fore-wheels  of  all  carriages  ought  to 
be  so  high  as  to  have  their  axles  even 
with  the  breasts  of  the  horses,  which 
would  not  only  give  the  horses  a  fair 
draught,  but  likewise  cause  the  machine 
to  be  drawn  by  a  less  degree  of  power. 

When  the  spokes  are  inclined  to  the 
nave?  the  wheels  are  said  to  be  concave, 
or  dishing.  But  it  is  allowed,  on  all 
hands,  that  perpendicular  spokes  are  pre- 
ferable on  level  ground.  The  inclination 
of  the  spokes,  therefore,  which  may  ren- 
der concave  wheels  advantageous  in  rug- 
ged and  unequal  roads,  renders  them  dis- 
advantageous when  the  roads  are  in  good 
order. 

M.  Camus  showed  that  the  line  of  trac- 
tion should  be  a  horizontal  line,  or  rather, 
that  it  should  always  be  parallel  to  the 
ground  on  which  the  carriage  is  moving, 
both  because  the  horse  can  exert  his 
greatest  strength  in  this  direction,  and 
because  the  line  of  draught,  being  per- 
pendicular to  the  vertical  spoke  of  the 
wheel,  acts  with  the  greatest  possible 
leverage.  M.  Deparcieux  shows,  in  the 
most  satisfactory  manner,  that  animals 
draw  by  their  weight,  joined  to  the  force 
of  their  muscles.  In  four-footed  animals, 
the  hind-feet  are  the  fulcrum  of  the  le- 
ver by  which  their  weight  acts  against 
the  load,  and  when  the  animal  pulls 
hard,  it  depresses  its  chest,  and  thus  in- 
creases the  lever  of  its  weight,  and  di- 
minishes the  lever  by  which  the  load 
resists  its  efforts. 

Noiseless  wheels. — A  patent  has    been 
taken  out  for  dulling  the  sound  of  wheels. 
In  this  instance  the   invention   consists 
in    the   application   of  a    solid   band  of 
vulcanized   India-rubber   over  the  iron 
tire  of  the  wheel.     The  India-rubber  is 
held  in  its  place  by  the  tire  having  a  rais- 
ed rim  on   both  sides,  and  by  its   own 
elasticity.      The   band    of    an    ordinary 
carriage  wheel  is  about  an   inch  to  one 
inch  and  a  half  in  thickness,    and,  un- 
less  on    close    inspection,  no  difference 
from  the  common  iron-shod  wheel  is  per- 
ceptible.    We  have  driven  some  distance 
in  a  carriage  with  the  wheels  so  shod, 
and  were  struck,  not  only  with  its  noise- 
j  lessness,  but  at  the  perfect  smoothness 
of  the  motion — the  wheels  being,  in  fact, 
j  springs,  and,  by  their  elasticity,  giving 
J  a  lighter  draught  than  with  the  iron  tire. 
'  One   set  of  wheels,    which    have   been 
j  driven  4000  miles,  have  here  and  thero 


680 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[win 


a  trifling  cut,  but  show  no  appearance 
of  being  worn  out,  and  seem  quite  ca- 
pable of  another  three  or  four  thousand. 
An  iron  tire  is  generally  worn  out  in 
3,000  miles,  so  that  the  India  rubber  tire 
has  so  far  proved  itself  the  more  lasting. 
It  is  certainly  a  great  addition  to  the  lux- 
ury of  a  carriage  to  have  it  run  without 
jar  or  noise  ;  and  it  would  be  a  universal 
comfort  to  have  the  streets  of  cities 
without  the  present  incessant  rattle  of 
carriages,  omnibuses,  &c. 

WHITE  LEAD.  Carbonate  of  Lead; 
Painters''  White.  Lead  is  converted  into 
carbonate  in  the  following  way  : — The 
metal  is  cast  into  the  form  of  a  network 

f;rating,  in  moulds  about  fifteen  inches 
ong,  and  four  or  five  broad.  Several 
rows  of  these  are  placed  over  cylindrical 
glazed  earthen  pots,  about  four  or  five 
inches  in  diameter,  containing  some  trea- 
cle-vinegar, which  are  then  covered  with 
straw  ;  above  these  pots  another  range  is 
piled,  and  so  in  succession,  to  a  conve- 
nient height.  The  whole  are  imbedded 
in  spent  bark  from  the  tan-pit,  brought 
into  a  fermenting  state  by  being  mixed 
with  some  bark  used  in  a  previous  pro- 
cess. The  pots  are  left  undisturbed 
under  the  influence  of  a  fermenting  tem- 
perature for  eight  or  nine  weeks.  In  the 
course  of  this  time  the  lead  gratings 
become,  generally  speaking,  converted 
throughout  into  a  solid  carbonate,  which 
when  removed  is  levigated  in  a  proper 
mill,  and  elutriated  with  abundance  of 
pure  water.  The  plan  of  inserting  coils 
of  sheet  lead  into  earthenware  pipkins 
containing  vinegar,  and  imbedding  the 
pile  of  pipkins  in  fermenting  horse-dung 
and  litter,  is  now  little  used  ;  because 
the  coil  is  not  uniformly  acted  on  by  the 
acid  vapors,  and  the  sulphureted  hydro- 
gen evolved  from  the  dung  is  apt  to 
darken  the  white  lead. 

In  the  above  processes,  the  conversion 
of  lead  into  carbonate  seems  to  be  ef- 
fected by  keeping  the  metal  immersed  in 
a  warm,  humid  atmosphere,  loaded  with 
carbonic  and  acetic  acids ;  and  hence  a 
pure  vinegar  does  not  answer  well,  but 
one  which  is  susceptible,  by  its  sponta- 
neous decomposition  in  these  circum- 
stances, of  yielding  carbonic  acid.  Such 
are  tartar,  wine  lees,  molasses,  &c. 

Another  process  has  been  practised  to 
a  considerable  extent  in  France,  though 
it  does  not  afford  a  white  lead  equal  in 
body  and  opacity  to  the  products  of  the 
preceding  operations.  M.  Thenard  first 
established  the  principle,  and  MM.  Bre- 
choz  and  Leseur  contrived  the  arrange- 


ments of  this  new  method,  which  was 
subsequently  executed  on  a  great  scale 
by  MM.  Board  and  Brechoz. 

A  subacetate  of  lead  is  formed  by  di- 
gesting a  cold  solution  of  uncrystallized 
acetate,  over  litharge,  with  frequent  agi- 
tation. It  is  said  that  65  pounds  of  puri- 
fied pyroligneous  acid,  of  specific  gravity 
1-056,  require,  for  making  a  neutral  ace- 
tate, 58  pounds  of  litharge  :  and  hence, 
to  form  the  subacetate,  three  times  that 
quantity  of  base,  or  174  pounds,  must  be 
used.  The  compound  is  diluted  with 
water  as  soon  as  it  is  formed,  and  being 
decanted  off  quite  limpid,  is  exposed  to 
a  current  of  carbonic  acid  gas,  which, 
uniting  with  the  two  extra  proportions 
of  oxide  of  lead  in  the  subacetate,  pre- 
cipitates them  in  the  form  of  a  white  car- 
bonate, while  the  liquid  becomes  a  faintly 
acidulous  acetate.  The  carbonic  acid 
may  be  extricated  from  chalk,  or  other 
compounds,  or  generated  by  combustion 
of  charcoal,  as  at  Clichy ;  but  in  the  lat- 
ter case,  it  must  be  transmitted  through 
a  solution  of  acetate  of  lead  before  being 
admitted  into  the  subacetate,  to  deprive 
it  of  any  particles  of  sulphureted  hydro- 
gen. When  the  precipitation  of  the  car- 
bonate of  lead  is  completed,  and  well  set- 
tled down,  the  supernatant  acetate  is  de- 
canted off,  and  made  to  act  on  another 
dose  of  litharge.  The  deposit  being  first 
rinsed  with  a  little  water,  this  washing  is 
added  to  the  acetate  ;  after  which  the 
white  lead  is  thoroughly  elutriated.  This 
repetition  of  the  process  may  be  indefi- 
nitely made  ;  but  there  is  always  a  small 
loss  of  acetate,  which  must  be  repaired, 
either  directly  or  by  adding  some  vine- 
gar. 

WHITING.  Chalk  carefully  cleared 
of  all  stony  matter,  ground,  levigated,  and 
made  up  into  small  oblong  cakes.  As  it 
is  often  used  as  a  polishing  material,  it 
should  be  very  carefully  freed  from  all 
particles  of  flint  or  sand. 

WHITE  VITEIOL.  The  old  name  of 
sulphate  of  zinc.     (See  Zinc.) 

WHITEWASH.  A  mixture  of  whit- 
ing, size,  and  water,  for  whitening  ceil- 
ings and  walls. 

WINCH.  In  mechanics,  a  bent  handle 
or  rectangular  lever,  for  turning  a  wheel, 
grindstone,  <fec.  The  term  winch  is  also 
popularly  applied  to  the  windlass.  (See 
Windlass.) 

WINDLASS.  A  machine  used  for 
many  common  purposes.  It  is  a  par- 
ticular modification  of  the  wheel  and 
axle,  the  power  being  applied  by  means 
of  a  rectangular  lever  or  winch.    The  arm 


tvinJ 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


681 


of  the  winch  represents  the  radius  of  the 
wheel ;  and  the  power  is  applied  at  right 
angles.  The  windlass  is  frequently  used 
in  merchant  ships  or  small  trading  ves- 
sels instead  of  a  capstan  for  heaving  the 
anchors,  &c.  In  this  case  it  consists  of 
a  large  cylindrical  piece  of  timber  laid  in 
a  horizontal  position,  and  supported  at 
its  two  ends  by  two  pieces  of  wood  called 
knight-heads  placed  on  opposite  sides  of 
the  deck  near  the  foremast.  This  axle  is 
pierced  with  holes  directed  towards  the 
centre,  in  which  long  levers  are  inserted, 
called  handspikes.  It  is  furnished  with 
strong  pauls  to  prevent  it  from  turning 
backwards  when  the  pressure  on  the 
handspikes  is  intermitted. 

WINDMILL.  In  mechanics,  a  mill 
which  receives  its  motion  from  the  im- 
pulse of  the  wind.  The  general  appear- 
ance of  the  windmill  is  familiar  to  every 
one.  The  building  containing  the  ma- 
chinery is  usually  circular.  To  the  ex- 
tremity of  the  principal  axis,  or  wind- 
shaft,  are  attached  rectangular  frames 
(generally  five),  on  which  cloth  is  usually 
stretched  to  form  the  sails.  The  surfaces 
of  the  sails  are  not  perpendicular  to  the 
axis,  but  inclined  to  it  at  a  certain  angle, 
about  72°  at  the  extremities  nearest  to 
the  axle,  and  83°  at  the  farther  extremi- 
ties ;  so  that  their  form  is  in  some  degree 
twisted,  and  different  from  a  plane  sur- 
face. Suppose  the  axis  to  be  placed  in 
the  direction  of  the  wind  ;  the  wind  will 
then  strike  the  sail  obliquely,  and  the 
force  may  therefore  be  resolved  into  two 
parts,  one  of  which,  acting  in  the  direc- 
tion perpendicular  to  the  axis,  gives  a 
motion  of  rotation  to  the  sails,  and  con- 
sequently to  the  wind-shaft,  from  which 
it  is  communicated  to  the  machinery. 
The  wind-shaft  is  inclined  to  the  horizon 
in  an  angle  of  from  8°  to  15°,  principally 
with  a  view  to  allow  room  for  the  action 
of  the  wind  at  the  lower  part,  where  it 
would  be  weakened  if  the  sails  came  too 
nearly  in  contact  with  the  building. 

As  the  direction  of  the  wind  is  con- 
stantly changing,  some  apparatus  is  re- 
quired for  bringing  the  axle  and  sails 
into  their  proper  position.  This  is  some- 
times effected  by  supporting  the  machin- 
ery on  a  strong  vertical  axis,  the  pivot  of 
which  moves  in  a  socket  firmly  fixed  in 
the  ground;  so  that  the  whole  structure 
may  be  turned  round  by  a  lever.  But  it 
is  now  usual  to  construct  the  building 
with  a  movable  roof,  which  revolves  up- 
on friction  rollers ;  and  the  shaft  being 
fixed  in  the  roof  is  brought  round  along 
with  it.  The  roof  is  brought  into  the 
29* 


required  position  by  means  of  a  small 
vane  wheel  furnished  with  wind  sails, 
which  turn3  round  when  the  wind  strikes 
on  either  side  of  it,  and  drives  a  pinion 
which  works  into  the  teeth  of  a  large 
crown  wheel  connected  with  and  sur- 
rounding the  movable  roof. 

Of  the  form  and  position  of  the  sails. — 
From  the  investigations  of  Parent  and 
Belidor,  it  appears  that  the  maximum 
effect  of  the  wind  on  the  sails  is  pro- 
duced when  their  inclination  to  the  axis 
of  rotation  is  about  54|  degrees ;  or  when 
the  angle  of  weather,  that  is  to  say,  the 
angle  formed  by  the  plane  of  the  sail  and 
the  plane  of  its  revolution,  is  35£  degrees. 
But  this  result,  being  obtained  from  con- 
sidering the  effect  of  the  wind  on  the 
sails  when  at  rest,  does  not  agree  with 
that  which  is  found  by  experiment.  In 
fact,  as  the  velocity  of  the  sail  tends  to 
withdraw  it  from  the  wind,  it  is  neces- 
sary to  counteract  the  diminution  of  force 
by  diminishing  the  angle  of  weather,  or 
to  bring  the  sail  into  such  a  position  that 
the  wind  strikes  its  surface  more  directly : 
and  since  the  velocity  of  the  different 
parts  of  the  sail  is  in  proportion  to  their 
distance  from  the  axis,  it  follows  that  in 
order  to  produce  the  greatest  effect  every 
elementary  portion  of  it  ought  to  have  a 
different  angle  of  weather,  diminishing 
from  the  centre  to  the  extremity  of  the 
sail. 

From  the  experiments  of  Smeaton,  it 
appears  that  the  following  positions  are 
the  best.  Suppose  the  radius  to  be  divid- 
ed into  six  equal  parts,  and  call  the  first 
part,  beginning  from  the  centre,  one,  the 
second  two,  and  so  on,  the  extreme  part 
being  six : — 

Angle  Angle  with  the 

with  Plane  of  Motion,  or 

No.  the  Axis.  Angle  of  Weather. 

1 72Q ISO 

2 71  19 

3 72  18 

4 74  16 

5 77* 12J 

6 83  7 

As  it  is  necessary  that  a  windmill  should 
face  the  wind  from  whatever  point  it 
blows,  the  whole  mill  is  made  to  turn 
upon  a  strong  vertical  post,  and  is  there- 
fore called  a  post-mill ;  but,  commonly, 
the  roof  or  head  only  revolves,  carrying 
with  it  the  windwheel  and  its  shaft,  the 
weight  being  supported  on  friction  rol- 
lers. 

The  following  are  the  maxims  of  Smea- 
ton with  regard  to  mills: — 1.  The  velo- 
city of  windmill  sails,  whether  loaded  or 
unloaded,  so  as  to  produce  a  maximum 


682 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[wiR 


effect,  is  nearly  as  the  velocity  of  the 
wind,  their  shape  and  position  being  the 
same.  2.  The  load  at  the  maximum  is 
nearly,  but  somewhat  less,  as  the  square 
of  the  velocity  of  the  wind,  the  shape 
and  position  of  the  sails  being  the  same. 
3.  The  effects  of  the  same  sails  atamaxi- 
mum  are  nearly,  but  somewhat  less,  as 
the  cubes  of  the  velocity  of  the  wind.  4. 
The  load  of  the  same  sails  at  the  maxi- 
mum is  nearly  as  the  squares,  and  their 
effects  as  the  cubes,  of  their  number  of 
turns  in  a  given  time.  5.  "When  the 
sails  are  loaded  so  as  to  produce  a  maxi- 
mum effect  at  a  given  velocity,  and  the 
velocity  of  the  wind  increases,  the  load 
continuing  the  same,  then  the  increase  of 
effect,  when  the  increase  of  the  velocity 
of  the  wind  is  small,  will  be  nearly  as  the 
square  of  those  velocities  ;  when  the  ve- 
locity of  the  wind  is  doubled,  the  effect 
is  nearly  as  10  to  27£.  "When  the  veloci- 
ties compared  are  more  than  double  of 
that  where  the  griven  load  produces  a 
maximum,  the  effects  compared  increase 
nearly  in  the  same  ratio  of  the  velocity 
of  the  wind.  6.  In  sails  where  the  posi- 
tions and  figures  are  similar  and  the  ve- 
locity of  the  wind  the  same,  the  number 
of  turns  in  a  given  time  will  be  recipro- 
cally as  the  radius  or  length  of  the  sail. 

7.  The  load  at  a  maximum  that  sails  of  a 
similar  figure  and  position  will  overcome 
at  a  given  distance  from  the  centre  of 
motion  will  be  as  the  cube  of  the  radius. 

8.  The  effects  of  sails  of  similar  figure 
and  position  are  as  the  square  of  the  ra- 
dius. 9.  The  velocity  of  the  extremities 
of  Dutch  sails,  as  well  as  of  the  enlarged 
sails  in  all  their  usual  positions,  when 
unloaded,  or  even  loaded  to  a  maximum, 
is  considerably  quicker  than  the  velocity 
of  the  wind. 

Horizontal  windmills. — Windmills  are 


•ometimes  constructed  in  such  a  manner 


that  the  planes  of  the  sails  intersect  each 
other  in  the  wind-shaft,  in  which  case 
they  are  called  horizontal  windmills  ;  be- 
cause the  wind-shaft  being  usually  verti- 
cal, the  sails  have  a  horizontal  motion. 
The  wind-shaft,  however,  might  be 
placed  with  equal  advantage  in  the  hori- 
zontal position. 

In  order  that  motion  may  be  commu- 
nicated to  the  machine,  the  impulse  of 
the  wind  on  the  returning  sail  must  be 
removed  by  screening  it  from  the  wind, 
or  at  least  diminished  by  making  it  pre- 
sent a  less  surface  when  returning  against 
the  wind.  The  first  of  these  methods  is 
said  to  be  practised  in  Tartary,  and  some 
provinces  in  Spain  ;  it  is  the  simplest  and 
probably  the  best.  The  other  method 
requires  the  sail  to  be  formed  of  several 
flaps  movable  on  hinges,  and  so  adjusted 
that  on  one  side  of  the  axis  they  present 
their  surfaces  to  the  wind,  and  when  re- 
turning on  the  other  only  their  edges. 
Other  contrivances  have  been  proposed  ; 
but  horizontal  windmills  are  greatly  in- 
ferior, in  point  of  effect,  to  those  which 
have  vertical  sails,  and  are  accordingly 
seldom  met  with. 

On  account  of  the  irregularity  of  the 
moving  force,  and  the  interruption  of 
calm  weather,  machines  impelled  by  the 
wind  can  only  be  used  advantagecsly 
for  purposes  which  are  not  urgent,  and 
where  regularity  is  not  indispensable. 
The  chief  purposes  to  which  they  are  ap- 
plied are  grinding  corn,  expressing  oil 
from  seeds,  bruising  oak  bark  for  tan- 
ning, sawing  wood,  raising  water,  &c. 
Windmills  were  brought  into  Europe  from 
the  East  about  the  time  of  the  Crusades  ; 
they  are  not  much  used  in  this  country. 
"WINDOW.  In  architecture,  an  aper- 
ture in  a  wall  for  the  admission  of  light 
and  air  to  the  interior.  In  distributing 
windows  so  that  there  be  had  a  suffi- 
ciency of  light,  it  is  usual  to  make  the 
piers  or  intervals  between  them  never 
less  than  the  width  of  the  window, 
and  never  more  than  two-widths  of  the 
same.  Where  it  is  required  to  ascertain 
the  total  area  of  light  necessary  for  a 
room,  the  following  empirical  rule  is  fre- 
quently used  :  Multiply  together  the 
length,  breadth,  and  height,  and  extract 
the"  square  root  of  the  product,  which 
will  be  the  area  of  lisrht  required. 

WINDSOR-BRICK  is  an  infusible  ma- 
terial, light,  and  easily  cut  into  desirable 
forms,  with  the  knife  or  saw,  for  the  use 
of  chemists  and  manufacturers. 

WIRE-DRAWING.  The  art  of  ex- 
tending the    ductile    metals  into  wire. 


woo] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


683 


The  operation  is  performed  by  casting  or 
hammering  the  metal  into  a  bar,  which  is 
then  successively  drawn  through  holes  in 
a  steel  plate,  each  being  smaller  than  the 
other,  until  the  requisite  fineness  is  at- 
tained. The  holes  through  which  ex- 
tremely fine  wires  of  platinum,  gold,  or 
silver  are  occasionally  drawn,  are  some- 
times made  in  a  diamond  or  ruby.  (See 
Gold  and  Silver.) 

WOAD.  A  continental  European 
plant,  which  yields  a  blue  dye  to  woollen 
cloth.  The  large  leaves  are' gathered,  in 
France,  several  times  in  a  year,  and 
ground  into  paste  at  a  Brill.  It  is  then 
laid  in  heaps  to  ferment,  formed  into 
balls,  and  dried.  The  dyers  pound  it 
again,  and  ferment  it  with  water.  It  is 
then  dissolved  in  boiling  water,  and  a 
20th  slaked  lime  added,  by  which  it  fer- 
ments, turns  blue  and  red,  and  finally 
dyes  woollens  green,  which,  in  the  air, 
change  to  bine.  Woad  grows  luxuriantly 
in  this  country. 

WOOD,  in  plants,  physiologically  con- 
sidered, is  the  support  of  all  the  de- 
ciduous organs  of  respiration,  digestion, 
and  impregnation;  the  deposit  of  the  se- 
cretions peculiar  to  the  individual  spe- 
cies ;  and  also  the  reservoir  from  which 
the  newly  forming  parts  derive  their  sus- 
tenance until  they  can  establish  a  com- 
munication with  the  soil.  It  consists 
organically  of  woody  tissue,  and  various 
kinds  of  vessels  surrounded  by  cellular 
matter,  and  more  or  less  carefully  arran- 
ged. In  the  youngest  state  it  is  succu- 
lent and  brittle,  and  is  of  nearly  the  same 
Suality  in  all  plants  ;  but  as  it  gains  age, 
le  sides  of  the  woody  tissues  become 
hardened  and  thickened  by  the  deposit 
within  them  of  matter  of  solidification, 
and  wood  then  assumes  the  colors  and 
appearances  peculiar  to  different  species. 
In  the  young  state  it  is  called  sapwood  or 
alburnum  ;  when  hardened  and  colored 
it  becomes  duramen  or  heartwood.  It 
abounds  in  nitrogen,  which  may  be  re- 
moved by  simple  washing ;  aud  it  is 
supposed  that  the  perishable  quality  of 
wood  is  owinw  to  the  presence  of  this 
element.  It  is  oelieved  that  the  preserv- 
ing power  of  certain  agents  employed  to 
render  wood  durable  depends  upon  their 
rendering  the  azotized  matter  iusoluble. 

WOOD  COAL.  A  synonym  orbrown 
coal. 

WOOD  ENGRAVING.  (See  Engrav- 
ing.) 

WOOD   OPAL.    An  opalized  quartz 
occurring  in  various  vegetable  forms. 
WOODSTONE.    Petrified  wood. 


WOOD  TIN.  An  opaque,  fibrou  ,  and 
nodular  variety  of  oxide  of  tin,  of  a 
brown  color,  hitherto  only  found  in  Corn- 
wall. 

WOODY  FIBRE.  Very  slender,  trans- 
parent membranous  tubes,  tapering 
acutely  to  each  end,  lying  in  bundles  in 
the  tissue  of  plants,  and  having  no  direct 
communication  with  each  other.  They 
are  of  extreme  tenuity,  and  form  the  sub- 
stances called  hemp  and  flax. 

WOOD  PRESERVATION.  If  proper 
ly  seasoned,  timber,  placed  in  a  dry  situa- 
tion with  a  free  circulation  of  air  round 
it,  is  very  durable,  and  has  been  known 
to  last  for  several  hundred  years  without 
apparent  deterioration.  This  is  not,  how- 
ever, the  case  when  exposed  to  moisture, 
which  is  always  more  or  less  prejudicial 
to  its  durability. 

When  timber  is  constantly  under 
water,  the  action  of  the  water  dissolves 
a  portion  of  its  substance,  which  is  made 
apparent  by  its  becoming  covered  with  a 
coat  of  slime.  If  it  be  exposed  to  alter- 
nations of  dryness  and  moisture,  as  in 
the  case  of  piles  in  tidal  waters,  the  dis- 
solved parts  being  continually  removed 
by  evaporation  and  the  action  of  the 
water,  new  surfaces  are  exposed,  and  the 
wood  rapidly  decays. 

Where  timber  is  exposed  to  heat  and 
moisture,  the  albumen  or  gelatinous  mat- 
ter in  the  sapwood  speedily  putrefies  and 
decomposes,  causing  what  is  called  rot. 
The  rot  in  timber  is  commonly  divided 
into  two  kinds,  the  wet  and  the  dry  ;  but 
the  chief  difference  between  them  is,  that 
where  the  timber  is  exposed  to  the  air, 
the  gaseous  products  are  freely  evaporat- 
ed ;  whilst,  in  a  confined  situation,  they 
combine  in  a  new  form,  viz.,  the  dry-rot 
fungus,  which,  deriving  its  nourishment 
from  the  decaying  timber,  often  grows  to 
a  length  of  many  feet,  spreading  in  every 
direction,  and  insinuating  its  delicate  fi- 
bres even  through  the  joints  of  brick  walls. 

In  addition  to  the  sources  of  decay 
above  mentioned,  timber  placed  in  sea 
water  is  very  liable  to  be  completely  de- 
stroyed by  the  perforations  of  the  worm, 
unless  protected  by  copper  sheathing. 

The  oest  method  of  protecting  wood- 
work from  decay,  when  exposed  to  the 
weather,  is  to  paint  it  thoroughly,  so  as 
to  prevent  its  being  affected  by  moisture. 

It  is,  however,  most  important  not  to 
apply  paint  to  any  wood-work  which  has 
not  been  thoroughly  seasoned ;  for  in 
this  case  the  evaporation  of  the  sap  being 
prevented,  it  decomposes^  and  the  wood 
rapidly  decays. 


684 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[yfoo 


Many  plans  have  been  proposed  for  the 
prevention  of  the  rot.  Kyan's  process 
consists  in  impregnating  the  timber  with 
corrosive  sublimate,  thus  converting  the 
albumen  into  an  indecomposable  sub- 
stance. This  method,  although  not  al- 
ways successful,  is  undoubtedly  of  great 
use,  particularly  where  inferior  or  imper- 
fectly seasoned  timber  has  to  be  used. 
It  is,  however,  said  to  render  the  wood 
brittle. 

Payens's  process  consists  in  impregnat- 
ing the  wood  with  metallic  oxides,  alka- 
lies, or  eartbs,  as  may  be  required,  and 
decomposing  them  in  the  wood,  forming 
new  and  insoluble  compounds.  The  usual 
preparation  was  first  injecting  into  the 
timber  a  solution  of  sulphate  of  iron, 
and  then  one  of  chloride  ot  calcium.  An 
air  pump  was  used  to  draw  the  liquids 
into  the  pores  of  the  wood.  Timber 
thus  prepared  will  not  burn,  but  only 
smoulders. 

A  process  invented  by  a  Mr.  Bethell, 
and  very  good  in  railway  works,  is  to 
impregnate  the  timber  with  oil  of  tar  : 
this  appears  to  be  very  successful  in  pre- 
venting decay,  but  the  danger  of  acci- 
dents from  fire  is  much  increased. 

Dr.  Boucherie's  process  of  impregnat- 
ing timber  was  with  a  solution  ot  sul- 
phate of  copper.  After  the  varnishing, 
the  appearance  of  the  wood  is  rich,  and 
is  said  to  be  permanent.  The  Dr.  con- 
fines his  application  of  it  to  the  soft  wood 
generally  ;  and  he  exhibited  at  a  French 
meeting*  a  work-box  so  impregnated, 
made  of  a  tree  within  three  months  after 
it  was  cut.  He  showed  a  block  sawed 
into  three  sections,  but  not  disconnected, 
which  had  been  buried  for  six  years  in  a 
fungus  pit.  It  is  of  pine,  and  immediate- 
ly after  being  felled,  the  two  side  sections 
were  impregnated  by  means  of  the  natu- 
ral action  of  the  sap  vessels  of  the  wood, 
the  one  with  the  dento-chloride  of  mer- 
cury (corrosive  sublimate,  as  recommend- 
ed by  Kyan),  800  grammes  of  1-5  per 
cent.*  strength  ;  the  other  with  S00 
grammes  of  sulphate  of  copper,  of  1-5  per 
cent.  The  centre  section  was  left  in  its 
natural  state.  The  block  shows  the  por- 
tions which  were  left  in  a  natural  state, 
and  that  impregnated  with  the  corrosive 
sublimate,  equally  and  completely  rot- 
ten, the  fibre  destroyed,  and  the  wood 
crumbling  into  dust, 'while  the  section 
marked  as  impregnated  with  the  sul- 
phate is  perfectly  sound  and  good.  It  is 
said,  that  traversers  and  sleepers  on  rail- 
ways so  impregnated  have  been  used  six 
years,  and  are  still  sound. 


WOOL.  A  term  used  very  indefinite- 
ly, being  applied  both  to  the*  fine  hair  of 
animals,  as*  sheep,  rabbits,  some  species 
of  goats,  &c,  and  to  fine  vegetable  fibres, 
as  cotton  (called  in  German  baumwolle, 
or  tree-wool) ;  but  when  used  without  re- 
striction it  is  generally  confined  to  the 
wool  of  sheep — a  substance  which,  from 
the  remotest  period  of  history,  has  been 
of  primary  importance  to  mankind.  In 
reierence  to  textile  fabrics,  sheep's  wool 
is  of  two  different  sorts,  the  short  and 
the  long  stapled;  each  of  which  requires 
different  modes  of  manufacture  in  the 
preparation  and  spinning  processes,  as 
also  in  the  treatment  of  the  cloth  after  it 
is  woven,  to  fit  it  for  the  market.  Each 
of  these  is,  moreover,  distinguished  in 
commerce  by  the  names  of  fieece  wools 
and  dead  wools,  according  as  they  have 
been  shorn  at  the  usuaf  annual  period 
from  the  living  animal,  or  are  cut  from 
its  skin  after  death.  The  latter  are  com- 
paratively harsh,  weak,  and  incapable  of 
imbibing  the  dyeing  principles,  more 
especially  if  the  sheep  has  died  of  some 
malignant  distemper.  The  annular  pores, 
leading  into  the  tubular  cavities  of  the 
filaments,  seem,  in  this  case,  to  have 
shrunk  and  become  obstructed.  The 
time  of  year  for  sheep-shearing  most  fa- 
vorable to  the  quality  of  the  wool  and  the 
comfort  of  the  animal,  is  towards  the  end 
of  June  and  the  beginning  of  Jnly  in 
England  ;  in  this  country  it  is  somewhat 
later :  generally  in  the  month  of  Au- 
gust. 

The  wool  of  the  sheep  has  been  sur- 
prisingly improved  by  its  domestic  cul- 
ture. The  movflon  (Ovte  aries),  the  pa- 
rent stock  from  which  our  sheep  is  un- 
doubtedly derived,  and  which  is  still 
found  in  a  wild  state  upon  the  mountains 
of  Sardinia,  Corsica,  Barbary,  Greece, 
and  Asia  Minor,  has  a  very*  short  and 
coarse  fleece,  more  like  hair  than  wool. 
When  this  animal  is  brought  under  the 
fostering  care  of  man,  the  rank  fibres 
gradually  disappear  •  while  the  soft  wool 
round  their  roots,  little  conspicuous  in 
the  wild  animal,  becomes  singularly  de- 
veloped. The  male  most  speedily  under- 
goes this  change,  and  continues  ever  after- 
ward to  possess  far  more  power  in  modi- 
fying the  fleece  of  the  offspring  than  the 
female  parent.  The  produce  of  a  breed 
from  a  coarse-woolled  ewe  and  a  finc- 
woolled  ram  is  not  of  a  mean  quality  be- 
tween the  two,  but  halfway  nearer  that 
of  the  sire.  By  coupling  the  female  thus 
generated  withsuch  a  nale  as  the  former, 
another  improvement  of  one  half  will  be 


woo] 


CYCLOPEDIA  OF  THE  USEFUL  ARTS. 


685 


obtained,  affording  a  staple  three  fourths 
finer  than  that  of  the  grandam.  By  pro- 
ceeding inversely,  the  wool  would  be  as 
rapidly  deteriorated.  It  is,  therefore,  a 
matter  of  the  first  consequence  in  wool 
husbandry,  to  exclude  from  the  flock  all 
coarse-fleeced  rams. 

Long  wool  is  the  produce  of  a  peculiar 
variety  of  sheep,  and  varies  in  the  length 
of  its  fibres  from  3  to  8  inches.  Such 
wool  is  not  carded  like  cotton,  but  comb- 
ed like  flax,  either  by  hand  or  appropri- 
ate machinery.  Short  wool  is  seldom 
longer  than  3  or  4  inches;  it  is  suscepti- 
ble of  carding  and  felting,  by  which  pro- 
cesses the  filaments  become  first  convo- 
luted, and  then  densely  matted  together. 
The  shorter  sorts  of  the  combing  wool  are 
used  principally  for  hosiery,  though  of 
late  years  the  finer  kinds  have  been  ex- 
tensively worked  up  into  merino  and 
mousscfine-de-laine  tabrics.  The  longer 
wools  of  the  Leicestershire  breed  are 
manufactured  into  hard  yarns,  for  worsted 
pieces,  such  as  waistcoats,  carpets,  bom- 
bazines, poplins,  crapes,  &c. 

The  wool  of  which  good  broadcloth  is 
made  should  be  not  only  shorter,  but, 
generally  speaking,  finer  and  softer  than 
the  worsted  wools,  in  order  to  fit  them 
for  the  fulling  process.  Some  wool-sort- 
ers and  wool- staplers  acquire  by  practice 
great  nicety  of  discernment  in  judging  of 
wools  by  the  touch  and  traction  of  the 
fingers.  Dr.  Ure  made  a  large  series  of 
observations  upon  different  wools,  and 
published  the  results.  The  filaments  of 
the  finer  qualities  varied  in  thickness 
from  l-1100th  to  l-1500th  of  an  inch; 
their  structure  is  very  curious,  exhibit- 
ing, in  a  good  achromatic  microscope,  at 
intervals  of  about  l-300th  of  an  inch,  a 
series  of  serrated  rings,  imbricated  to- 
wards each  other,  like  the  joints  of  Equi- 
setum,  or,  rather,  like  the  scaly  zones  of  a 
serpent's  skin. 

There  are  four  distinct  qualities  of  wool 
upon  every  sheep  ;  the  finest  being  upon 
the  spine,  from  the  neck  to  within  six 
inches  of  the  tail,  including  one  third  of 
the  breadth  of  the  back  ;  the  second  co- 
vers the  flanks  between  the  thighs  and 
the  shoulders ;  the  third  clothes  the  neck 
and  the  rump ;  and  the  fourth  extends 
upon  the  lower  part  of  the  neck  and 
breast  down  to  the  feet,  as  also  upon  a 
part  of  the  shoulders  and  the  thighs,  to 
the  bottom  of  the  hind  quarter.  These 
should  be  torn  asunder,  and  sorted,  im- 
mediately after  the  shearing. 

The  harshness  of  wools  is  dependent 
not  ffclely  upon  the  breed  of  the  animal, 


or  the  climate,  but  is  owing  to  certain  pe- 
culiarities in  the  pasture,  derived  from 
the  soil.  It  is  known  that  in  sheep  fed 
upon  chalky  districts,  wool  is  apt  to  get 
coarse ;  but  in  those  upon  a  rich  loamy 
soil,  it  becomes  soft  and  silky.  The  ar- 
dent sun  of  Spain  renders  the  fleece  of 
the  Merino  breed  harsher  than  it  is  in  the 
milder  climate  of  Saxony.  Smearing 
sheep  with  a  mixture  of  tar  and  butter  is 
deemed  favorable  to  the  softness  of  their 
wool.  This  breed  flourishes  well  in  New 
England. 

All  wool,  in  its  natural  state,  contains  a 
quantity  of  a  peculiar  potash-soap,  secret- 
ed by  the  animal,  called  in  this  country 
the  yolk ;  which  may  be  washed  out  by 
water  alone,  with  which  it  forms  a  sort  of 
lather.  It  constitutes  from  25  to  50  per 
cent,  of  the  wool,  being  most  abundant 
in  the  Merino  breed  of  sheep ;  and  how- 
ever favorable  to  the  growth  of  the  wool 
on  the  living  animal,  should  be  taken  out 
soon  after  it  is  shorn,  lest  it  injure  the 
fibres  by  fermentation,  and  cause  them  to 
become  hard  and  brittle.  After  being 
washed  in  water,  something  more  than 
lukewarm,  the  wool  should  be  well  press- 
ed and  carefully  dried. 

Wool  is  much  cultivated  in  the  New- 
England  States,  especially  in  Vermont. 

WOOLLEN  MANUFACTURE.  The 
simplest  mode  of  giving  an  idea  of  the 
extent  of  operations  in  a  woollen  manu- 
factory, is  to  give  in  abridgment  the 
heads  of  the  several  processes" which  the 
wool  undergoes  until  it  comes  out  fitted 
for  the  market.  Thus,  no  less  than  25 
processes  may  be  enumerated : 

1.  There  are  men  employed  in  sorting 
the  wools  of  many  qualities  and  countries. 

2.  There  is  a  machine  of  many  rollers 
with  teeth,  for  what  is  called  devilling, 
or  willowing  the  wool,  which  means  the 
opening  of  its  locks. 

3.  There  are  machines  for  scribbling  or 
combing  it. 

4.  There  are  others,  Called  carders,  for 
forming  slivers,  or  short  rolls  of  the  wool. 

5.  There  is  a  travelling  or  sliding  ap- 
paratus called  a  billy,  for  slabbing  or  draw- 
ing out  the  slivers  into  six  times  their 
length. 

G.  The  slubbings  put  on  spindles  are 
then  spun,  by  means  of  mules,  machines 
well  known  in  cotton  factories,  and  in- 
vented by  Crompton,  who  lately  died  in 
poverty  at  Bury. 

7.  The  thread  is  then  formed,  by  wo- 
men, into  warps  for  the  looms. 

8.  The  weavers  size  and  dry  these 
warps  or  webs. 


686 


CYCLOPEDIA    OF    THE    USEFUL    ARTS. 


[tea 


9.  They  then  fix  them  on  their  beams, 
and  weave  the  cloth,  which,  as  delivered 
by  them,  is  little  better,  or  firmer,  than 
stout  flannel. 

10.  This  cloth  is  then  scoured. 

11.  It  is  afterwards  taken  to  the  bvr- 
lers,  a  room  of  women,  who  pick  the 
surface  and  clear  the  whole  from  foreign 
substances. 

12.  The  cloth  is  then  milled*,  a  process 
most  curious,  in  which,  by  being  beat 
with  wooden  hammers  of  3  cwt.  each,  for 
15  or  24  hours,  the  threads  of  the  web 
arc  driven  together,  and  the  width  re- 
duced from  11  quarters,  or  8  feet  3  inches, 
to  5  feet.  The  machines  are  called  stocks. 
The  backs  are  made  of  cast-iron,  and  the 
circular  blows  of  the  hammers,  and  the 
harmony  of  the  result  is  astonishing. 

13.  The  next  process  is  to  confer  a 
soft  nap  on  one  side  of  the  cloth  •  and 
this  is  effected  by  the  use  of  a  species  of 
thistle,  called  teasels,  the  heads  of  which 
are  placed  in  frames,  put  upon  cylinders, 
and  against  these  the  cloth  is  worked  for 
6  or  7  hours,  by  which  means  a  delicate 
and  lustrous  nap  is  raised,  which  consti- 
tutes the  beauty  of  cloth. 

14.  It  is  then  boiled  in  water  for  two 
hours,  by  which  its  glossy  surface  is 
fixed. 

15.  It  is  then  cropt,  or  reduced  to  a 
level  surface,  by  means  of  sheer  spiral 
blades,  fixed  upon  a  cylinder,  invented 
by  Mr.  I.  Collier,  of  Paris,  a  process  for- 
merly performed  in  a  very  clumsy  man- 
ner by  huge  shears. 

16.  It  is  then  boiled,  tentered,  and  dried 
in  a  house,  at  a  heat  of  100°  or  120°. 

17.  It  is  then  worked,  or  raised  again, 
by  means  of  teasels,  called  nwysing. 

18.  It  is,  finally,  cropt  lengthwise  and 
breadthwise. 

19.  At  this  period  it  undergoes  various 
brus/iings,  by  machines  contrived  for  that 
purpose. 

20.  Imperfections  are  then  fine-drawn 
by  men. 

21.  It  is  pressed,  by  a  Brahmah's  hy- 
draulic press,  with  a  force  of  100  tons, 
between  hot  iron  plates. 

22.  The  pressed  face  is  taken  off  by 
steaming  and  brushing. 

23.  It  is  cuttted  or  folded  into  lengths, 
as  pieces  for  sale. 

24.  If  blue,  the  wool  is  dyed  before  the 
manufacturing. 

25.  If  black,  it  is  dyed  after  being 
milled. 

Such  are  the  numerous  steps  by  which 
a  piece  of  superfine  woollen  cloth  is  pro- 
duced.   It  is  6  weeks  in  its  course,  or 


in  work.  The  weaving  occupies  3  or  4 
weeks,  and  is  the  only  part  of  the  process 
which  depends  on  the  workman. 

XANTIIIC  ACID.  An  acid  composed 
of  sulphur,  carbon,  hydrogen  and  oxygen, 
obtained  in  combination  with  potassa  by 
agitating  sulphuret  of  carbon  mixed  witn 
solution  of  pure  potassa  in  strong  alcohol. 
Its  compounds  are  mostly  of  a  yellow  co- 
lor, whence  its  name.  The  relative  pro- 
portions of  its  component  parts  have  not 
as  vet  been  satisfactorily  obtained. 

tEAST.  The  fermenting  froth  of 
worts. 

YEAST,  ARTIFICIAL.  Mix  two 
parts,  by  weight,  of  the  fine  flour  of  pale 
barley  malt  with  one  part  of  wheat  flour. 
Stir  50  pounds  of  this  mixture  gradually 
into  100  quarts  of  cold  water,  with  a 
wooden  spatula,  till  it  forms  a  smooth 
pap.  Put  this  pap  into  a  copper  over  a 
slow  fire;  stir  it  well  till  the  temperature 
rise  to  fully  155°  to  160°,  when  a  partial 
formation  to  sugar  will  take  place,  but 
this  sweetening  must  not  be  pushed  too 
far ;  turn  out  the  thinned  paste  into  a  fiat 
cooler,  and  stir  it  from  time  to  time.  As 
soon  as  the  wort  has  fallen  to  59°  Fahr., 
transfer  it  to  a  tub,  and  add  for  every  50 
quarts  of  it  1  quart  of  good  fresh  beer- 
yeast,  which  will  throw  the  woit  into 
brisk  fermentation  in  the  course  of  12 
hours.  This  preparation  will  be  good 
yeast,  fit  for  bakers'  and  brewers'  uses, 
and  will  continue  fresh  and  active  for  3 
days.    It  should  be  occasionally  stirred. 

When  beer-barm  has  become  old  and 
flat,  but  not  sour,  it  may  be  revived  by 
mixing  with  every  quart  of  it  a  small  po- 
tato, boiled,  peeled,  and  rubbed  down 
into  a  paste.  The  mixture  is  to  be  placed 
in  a  warm  situation,  where  it  will  speed- 
ily show  its  renewed  activity,  by  throw- 
ing up  a  froth  upon  its  surface.  It  must 
be  forthwith  incorporated  with  the 
dough,  for  the  purpose  of  baking  bread. 
When  the  barm  has  become  sour,  its 
acid  should  be  neutralized  with  a  little 
powdered  carbonate  of  soda,  and  then 
treated  as  above,  when  it  will,  in  like 
manner,  be  revived.  A  bottle  of  brisk 
small  beer  may  furnish  ferment  enough 
to  form,  in  this  way,  a  supply  of  good 
yeast  for  a  small  baking. 

The  German  yeast  employed  by  bakers 
in  baking  cakes  and  other/arc*^  bread,  is 
made  by  putting  the  vnterhe/e  into  thick 
sacks  of  linen  or  hempen  yarn,  letting 
the  liquid  part,  or  beer,  drain  away; 
placing  the  drained  sacks  between  boards, 
and  exposing  them  to  a  gradually  incxpas- 
ing  pressure"  till  a  mass  of  a  thin  chlesy 


kn] 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


consistence  is  obtained.  This  cake  is 
broken  into  small  pieces,  which  are  wrap- 
ped in  separate  linen  cloths  ;  these  par- 
cels are  afterwards  inclosed  in  wax-cloth , 
for  exportation.  The  yeast  cake  may  also 
be  rammed  hard  into  a  pitched  cask, 
which  is  to  be  closed  air-tight.  In  this 
state,  if  kept  cool,  it  maybe  preserved 
active  for  a  considerable  time.  When 
this  is  to  be  used  for  beer,  the  proportion 
required  should  be  mixed  with  a  quanti- 
ty of  worts  at  60°  Fahr.,  and  the  mixture 
left  for  a  little  to  work,  and  send  up  a  live- 
ly froth,  when  it  is  quite  ready  for  adding 
to  the  cooled  worts  in  the  fermenting  back. 

Yeast,  Patent.  Boil  6  ounces  of  hops 
in  3  gallons  of  water  3  hours  ;  strain  it  otf, 
and  let  it  stand  10  minutes;  then  add 
half  a  peck  of  ground  malt,  stir  it  well  up, 
and  cover  it  over ;  return  the  hops,  and 
put  the  same  quantity  of  water  to  them 
again,  boiling  them  the  same  time  as  be- 
fore, straining  it  otf  to  the  first  mash ; 
stir  it  up,  and  let  it  remain  4  hours,  then 
strain  it  off,  and  set  it  to  work  at  90°, 
with  3  pints  of  patent  yeast;  let  it  stand 
about  20  hours;  take  the  scum  off  the 
top,  and  strain  it  through  a  hair  sieve  ;  it 
will  be  then  fit  for  use.  One  pint  is  suf- 
ficient to  make  a  bushel  of  bread. 

YENITE.  A  ferruginous  silicate  of 
lime,  from  Elba ;  named  by  Lelievre,  its 
discoverer,  in  honor  of  the  battle  of  Jena. 

ZAFFRE.  An  impure  oxide  of  cobalt, 
obtained  by  exposing  the  native  arseni- 
nret  of  cobalt  broken  into  small  pieces  to 
the  action  of  heat  and  air  in  a  reverberat- 
ing furnace,  by  which  its  elements  are 
oxidized,  and  the  greater  part  of  the  ar- 
senic driven  off. 

ZANTHOPICRIN.  A  bitter  principle, 
obtained  from  the  bark  of  the  Zanthoxy- 
lon  caribceum.  It  forms  yellow  acicular 
crystals,  insoluble  in  ether,  but  readily 
soluble  in  alcohol,  and  sparingly  in  water. 

ZAX.  In  architecture,  a  tool  for  cut- 
ting slates. 

ZECHSTEIN.  A  magnesian  limestone, 
lying  under  the  red  sandstone. 

ZEIN.  A  substance  of  a  tough  elastic 
nature,  resembling  gluten,  but  said  to  be 
destitute  of  nitrogen,  contained  in  Indian 
wheat ;  the  produce  of  the  Zea  mays. 

ZEOLITE.  A  name  given  to  a  family 
of  minerals,  which,  when  heated  before 
the  blowpipe,  melt  with  considerable 
ebullition.  They  mostly  consist  of  silica, 
alumina,  lime,  and  water. 

ZERO.  A  term  generally  used  in  re- 
ference to  the  thermometer,  implying  the 
point  at  which  the  graduation  commences. 
The  zero  of  Keaumur's  and  of  the  centi- 


grade thermometer  is  the  freezing  point 
of  water.  The  zero  of  Fahrenheit's  scale 
is  82°  below  the  point  at  which  water 
congeals,  being  about  the  temperature  of 
a  mixture  of  salt  and  snow.  See  Thermo- 
meter. 

ZINC.  A  metal,  first  mentioned  by 
Paracelsus ;  but  its  ores  were  known  at  a 
much  earlier  period.  In  commerce  it  is 
often  called  spelter  ;  and  is  obtained  either 
from  the  native  carbonate  of  zinc,  called 
calamine,  or  from  the  native  sulphuret  or 
blende  of  mineralogists.  These  ores  are 
roasted  and  mixed  with  charcoal  or 
carboniferous  flux  ;  the  mixture  is  put 
into  a  kind  of  crucible  closed  at  top,  and 
perforated  at  bottom  by  an  iron  tube, 
which  passes  through  the  grate  of  the 
furnace  into  water;  the  vapor  of  the  zinc 
distils  downwards  through  this  tube,  and 
is  condensed  in  the  water.  The  first 
portions  are  impure,  containing  arsenic, 
and  often  cadmium,  in  which  case  the 
vapor  burns  with  what  the  workmen 
call  a  brown  blaze  ;  when  the  blue  blaze 
appears  the  zinc  is  collected.  The  zinc 
of  commerce  (which  is  not  quite  pure) 
has  a  peculiar  bluish  color  and  lustre,  a 
lamellar  and  crystalline  texture,  and  its 
specific  gravity  is  about  7.  At  common 
temperatures  it  is  tough  and  intractable 
under  the  hammer;  and  when  heated 
to  above  500°  it  becomes  brittle,  and 
fuses  at  about  770°.  But  at  tempera- 
tures between  220°  and  320°  it  becomes 
malleable  and  ductile ;  so  that  it  may  be 
beaten  out  under  the  hammer,  and  rolled 
into  sheets  and  leaves,  and  drawn  into 
wire,  in  a  manner  extremely  remarkable 
when  its  highly  crystalline  texture  is  con- 
sidered. Being  a  cheap  and  light  metal, 
and  one  which,  after  having  been  super- 
ficially oxidized,  long  resists  the  further 
action  of  air  and  water,  it  has  lately  been 
much  employed  as  a  substitute  for  lead 
in  lining  water  cisterns  and  covering 
buildings;  it  has  also  been  lately  employ- 
ed in  tne  curious  operation  of  transfer- 
ring printing  (under  the  name  of  xinco- 
graphy).  It  is  a  very  inflammable  metal, 
burning  in  the  flame  of  a  spirit  lamp  with 
a  brilliant  white  light;  but  the  oxide 
which  forms  interferes  with  its  continu- 
ous combustion,  which  can  only  be  car- 
ried on  at  a  high  red  heat,  when  the  va- 
Eor  of  the  metal  burns  with  an  intensely 
right  flame,  and  yields  at  the  same  time 
a  quantity  of  flocculent  oxide,  which  floats 
about  in  the  surrounding  air,  and  was 
formerly  called  philosophers''  wool,  pom- 
pholix,  and  nihil  album.  The  equivalent 
of  zinc  is   32  and  that  of  its  oxide  40. 


688 


CYCLOPEDIA    OF   THE    USEFUL    ARTS. 


[ZIR 


Though  zinc  is  apparently  without  action 
upon  water,  yet  it  is  a  most  oxidable  me- 
tal ;  but  the  insolubility  of  its  oxide  pro- 
tects it  from  farther  action,  so  that  when 
a  film  is  once  formed  upon  it,  it  resists  fur- 
ther change ;  but  when  a  little  acid  is 
present  in  the  water,  and  the  zinc  not 
quite  pure,  it  is  rapidly  acted  upon,  and 
oxidized  at  the  expense  of  the  water, 
which  evolves  abundance  of  hydrogen 
(when  dilute  sulphuric  acid  is  used), 
and  the  oxide  of  zinc  is  removed  and  dis- 
solved by  the  acid.  It  is  this  action 
which  renders  zinc  so  powerful  a  genera- 
tor of  electricity  in  the  voltaic  pile.  The 
salts  of  zinc  are  mostly  soluble,  and 
have  a  nauseous  astringent  and  metallic 
taste.  The  sulphate  of  zinc,  or  white  vi- 
triol, is  employed  in  medicine  as  an 
emetic  and  tonic,  and  the  oxide  and  car- 
bonate are  externally  used  in  the  form  of 
ointment.  The  chlorids  of  zinc  is  a  co- 
lorless compound,  fusible  at  a  heat  a  lit- 
tle above  212°,  and  known  to  the  older 
chemists  under  the  name  of  butter  of  zinc. 
It  is  much  used  for  soldering.  Brass  is 
an  alloy  of  zinc  and  copper. 

Franklinite,  which  is  a  carbonate  of 
zinc  mixed  with  silicates,  is  found  abun- 
dantly in  Sussex  and  Morris  counties, 
N.  J. ;  almost  all  the  American  zinc  (which 
is  of  great  purity)  is  manufactured  from  it. 
(See  Franklinite.) 


Zinc,  rolled  into  large  plates,  is  employ- 
ed as  a  substitute  for  lead  and  slates,  in 
the  roofing  of  buildings.  The  great  ad- 
vantage of  these  plates  of  zinc  is  their 
lightness,  being  only  about  one-sixth  part 
of  the  weight  of  lead.  They  do  not  rust, 
which  is  another  great  advantage,  and 
has  led  to  the  employment  of  zinc  pipes 
both  for  cold  and  not  water.  No  cover- 
ing is  better  adapted  for  verandas  and 
summer  houses. 

ZIMOME.  That  part  of  the  gluten  of 
wheat  which  is  insoluble  in  alcohol. 
"When  rubbed  in  a  mortar  with  powder- 
ed guaiacum,  it  produces  a  fine  blue  co- 
lor. 

ZIRCON.  A  mineral  chiefly  composed 
of  zirconia  and  silica,  found  in  the  sand 
of  the  rivers  of  Ceylon,  and  occasionally 
imbedded  in  primitive  rocks.  It  is  of 
various  colors,  and  when  transparent  is 
sometimes  used  in  iewelry. 

ZIRCONIUM.  The  metallic  base  of 
zirconia,  an  earth  discovered  in  1789,  by 
Klaproth,  in  the  jargon  or  zircon  of  Cey- 
lon. Zirconium  has  only  been  obtained 
in  the  form  of  a  black  powder,  which, 
when  heated  in  the  air,  burns  into  the 
oxide.  The  salts  of  zirconia  are  distin- 
guished from  those  of  alumina  and  glu- 
cina  by  being  precipitated  by  all  the  pure 
alkalies,  and  by  being  insoluble  when 
they  are  added  in  excess. 


THE   END. 


ADDENDA. 


ANASTATIC  PRINTING  :  the  pro- 
cess of  reproducing  copies  of  prints  and 
letter-press  by  means  of  a  printed  proof: 
by  moistening  the  proof  in  dilute  Nitric 
Acid,  and  laying  the  face  of  the  print  on 
the  smooth  surface  of  a.  zinc  plate,  and 
allowing  it  to  rest  for  a  short  time,  the 
acid,  adhering  to  the  paper,  will  be  trans- 
ferred to  the  plate  and  corrode  its  sur- 
face :  the  portion  of  the  paper  which  is 
covered  with  ink  is  protected,  and  this 
part  does  not  corrode  the  plate  ;  thus  the 
plate  is  corroded  where  the  printed  copy 
is  blank,  and  there  is  an  elevated  surface 
corresponding  to  the  lines  :  it  is  an  etched 
zinc  plate  :  if  this  be  treated  as  a  litho- 
graphic plate,  facsimiles  of  the  original 
can  be  produced.  The  objection  to  the 
use  of  Nitric  Acid  is  great,  as  the  origi- 
nal is  inevitably  destroyed.  Phosphoric 
Acid  is  now  used  preferably — this  acid 
does  not  corrode  the  zinc,  but  only  starts 
the  ink  which  is  transferred  to  the  plate, 
to  which  it  adheres — the  plate  thus  re- 
sembles perfectly  the  lithographic  stone, 
and  is  similarly  treated.  This  art  is  now 
continually  being  used  for  reproducing 
any  sheet  which  happens  to  be  defective 
when  a  work  is  nearly  completed. 

CARD-STRIPPER.  A  machine  for 
stripping  or  cleaning  the  waste  from  the 
top  cards  of  the  carding  engine.  In  card- 
ing, the  waste  or  refuse  collected  by  the 
top  cards,  requires  to  be  frequently  strip- 
ped off,  to  prevent  the  cards  choking. 
This  was  formerly  done  by  boys ;  the 
carding  engine  requiring  to  be  stopped  at 
intervals  for  the  purpose.  Several  ma- 
chines have  been  invented  for  the  pur- 
pose of  stripping  the  cards  while  the  en- 
gine is  in  operation,  but  have  usually 
failed  in  consequence  of  their  complicated 
construction.  A  machine  has  lately  been 
invented  by  Messrs.  Wilcox  &  Stillmans, 
of  Westerly,R.  I., which,  with  the  addition 
of  some  simple  mechanism  to  the  engines, 
will  keep  any  number  of  them  stripped. 
It  is  entirely  self-acting,  turning  over 
every  card  in  succession,  at  proper  inter- 
vals, stripping  it,  and  returning  to  its 
place.  It  may  be  considered  one  of  the 
most  valuable  inventions  connected  with 
the  process  of  cotton  spinning,  as  it  per- 


forms, without  interruption  to  the  opera- 
tion of  the  engines,  what  formerly  re- 
quired a  considerable  expenditure  of 
labor,  and  caused  a  great  loss  by  the 
periodical  stoppage  of  work. 

DIES,  in  mechanical  manipulation,  are 
tools  by  which  the  threads  of  screws  are 
cut.  They  consist  of  pieces  of  steel  held 
in  a  suitable  socket  or  stock,  and  so 
formed  that  their  inner  sides  form  parts 
of  a  hollow  cylinder,  in  which  is  cut  a 
female  or  hollow  screw,  which  would  fit 
to  the  screw  desired  to  be  cut.  The  edges 
of  the  joints  formed  between  the  dies 
are  sharpened,  and  notches  are  cut  in  the 
dies  themselves  to  make  additional  cut- 
ting edges.  By  turning  the  dies  upon  a 
rod,  the  cutting  edges  of  their  threads, 
cut  out  the  spaces  between  the  threads 
of  the  screw  ;  and  by  keeping  the  dies 

Eressed  closely  round,  tightening  screws 
eing  fitted  to  the  stock  for  the  purpose, 
a  perfect  screw  is  soon  cut  upon  the  rod. 
DRAINING  SUGAR,  is  now  most 
commonly  effected  by  the  centrifugal 
drainer  or  separator,  which  consists  of  a 
hollow  cylinder,  whose  sides  are  made  of 
porous  material,  such  as  wire  cloth.  This 
cylinder  has  a  very  rapid  rotary  motion 
given  to  it,  and  on  the  sugar  being  placed 
in  it,  it  is  thrown  by  centrifugal  force 
against  the  sides  of  the  cylinder,  and  all 
the  moisture  or  molasses  expelled,  passing 
through  the  wires  into  an  outer  cashier, 
at  the  bottom  of  which  there  are  suitable 
channels  to  draw  it  off.  This  is  a  great 
improvement  over  the  old  plan  of  allow- 
ing the  sugar  to  stand,  till  the  moisture 
had  drained  out  through  the  bottom,  as 
it  not  only  separates  it  more  perfectly, 
but  effects  an  incalculable  saving  in  time. 
The  latest  improvement  in  the  centrifugal 
separator,  is  providing  it  with  a  false  bot- 
tom, which,  after  the  separation  is  per- 
fect, ascends  to  the  top  of  the  cylinder 
and  empties  it,  thereby  obviating  the  ne- 
cessity of  stopping  it'for  that  purpose. 
It  can  be  charged  while  revolving. 

EQUALIZER.  An  apparatus  for  equal- 
izing the  propelling  power  of  steam  en- 
gines and  other  prime  movers.  Vurious 
contrivances  have  been  employed  for  this 
purpose,    more   especially  with    engines 


690 


ADDENDA. 


working  steam  expansively,  where  a  fluc- 
tuation in  the  pressure  of  the  impelling 
medium  affects  the  uniformity  of  the 
motion  of  the  main  shaft.  Among  the 
best  appliances  of  this  kind  may  be  no- 
ticed the  Power  Regulator,  recently  pat- 
ented by  Alfred  Gregory,  of  New  York. 
It  consists  of  a  small  piston  working 
within  a  cylinder  which  is  open  at  one 
end  to  the  steam  in  the  boiler,  and — if 
the  engine  is  of  the  condensing  Kind — at 
the  other  end  to  the  vacuum  of  the  con- 
denser. This  piston  is  operated  by  the 
engine  so  as  to  make  two  strokes  for 
every  one  of  the  engine  piston,  and  is 
made  to  act  as  a  drag  at  the  commence- 
ment, and  as  an  auxiliary  towards  the 
close  of  the  stroke  of  the  engine  piston, 
and  thus  to  equalize  the  propelling  power, 
without  reference  to  the  period  at  which 
the  steam  may  be  "cut  off."  Whatever 
may  be  the  fluctuation  in  the  impelling 
medium,  the  regulator  always  produces 
the  same  relative  effect  upon  the  engine. 

FELT  CLOTH,  is  cloth  produced  with- 
out weaving,  by  crossing  the  sheets  of 
batting  from  two  carding  engines,  and 
then  shrinking  them  until  they  are  closely 
matted  together.  A  kind  of  carpet  is 
manufactured  in  this  way,  the  pattern  be- 
ing printed  after  the  fabric  is  made. 

GAUGEj  in  mechanical  manipulation, 
is  a  term  given  to  all  instruments  for  set- 
ting out  distances,  or  for  measuring 
thickness  or  calibre,  and  to  almost  every 
device  which  serves  as  a  guide  by  which 
to  work  out  any  particular  form.'. 

GLYPHOGRAPHY.  A  method  of  ex- 
tending pictorial  illustrations,  invented 
by  Mr.  E.  Palmer,  of  London,  England. 
It  is  an  electrotype  process,  which  ena- 
bles the  artist  to  become  the  engraver  of 
his  own  work.  The  drawing  being  made 
upon  a  copper  plate,  upon  which  a  suita- 
ble ground  has  been  laid,  with  points  of 
the  proper  forms  to  produce  the  various 
species  of  line  required  to  bring  out  the 
desired  effect.  The  work  is  then  deep- 
ened by  a  rolling  process :  by  allowing 
rollers  to  lay  on  parts  of  the  plate  a  com- 
position of  Litharge  and  turpentine  :  re- 
peated layers  are  put  on  until  the  required 
depth  is  gained.  It  is  now  placed  in  a 
solution  of  sulphate  of  copper  in  connex- 
ion with  a  galvanic  battery.  Metallic 
copper  is  by  this  means  deposited  in  the 
lines  cut  through  the  grounding  of  the 

1)lates  by  the  drawing  points,  and  these 
)ecoming  gradually  filled  up,  the  copper 
spreads  over  the  whole  surface  of  the 
composition,  forming  a  plate  of  any  re- 
quired thickness.    The  face  of  this  new 


plate  is,  of  course,  when  separated,  found 
to  be  an  exact  counterpart  of  the  drawing, 
and  when  mounted  upon  a  suitable  block 
to  raise  it  to  the  proper  height,  may  be 
used  to  print  from  along  with  type-matter, 
as  if  it  were  a  wood  engraving.  To  make 
the  proper  grounding,  the  plate  is  stained 
black  with  sulphuret  of  potassium;  it  is 
then  warmed,  and  over  it  is  spread  a  very 
thin  layer  of  Burgundy  pitch,  white  wax, 
resin,  spermaceti  and  sulphate  of  lead, 
previously  fused  together.  This  white 
composition  is  uniformly  spread  over  the 
plates  to  one-thirtieth  of  an  inch  thick- 
ness. The  drawing  points  of  the  artist 
remove  the  white  composition,  wherever 
they  are  passed,  whereby  the  blackened 
surface  of  the  plate  is  exposed,  forming  a 
striking  contrast  with  the  surrounding 
white  ground,  so  that  the  artist  sees  his 
effect  at  once. 

GRAVITATION.  The  tendency  of  all 
matter  in  the  universe  towards  all  other 
matter.  This  universal  force  may  be 
enunciated  as  follows :  The  mutual  ten- 
dency of  two  bodies  towards  each  other 
increases  in  the  same  proportion  as  their 
masses  are  increased,  and  the  square  of 
their  distance  is  decreased  ;  and  it  de- 
creases in  proportion  as  their  masses  are 
decreased,  and  as  the  square  of  their  dis- 
tance is  increased. 

GRAVITY.    The  tendency  of  a  mass 
of  matter  towards  its  central  body ;  par- 
ticularly the  tendency  of  a  body  towards 
the  centre  of  the  earth,  which  is  some- 
times termed  terrestrial  gravitation.  The 
force  of  gravity  in  a  body  is  in  direct 
proportion  to  its  quantity  of  matter,  and 
is  measured  by  the  velocity  generated  in 
a  second  of  time.  It  has  been  ascertained 
j  by  experiment  that  a  body  falling  freely 
from   rest  will  descend  through  sixteen 
I  and  a  half  feet  in  the  first  second  of  time, 
;  and  will  then  have  acquired  a  velocity  of 
I  thirty-two  and  one-sixth  feet,  and  at  the 
'  end  of  each  succeeding  second  will  have 
i  acquired   an  additional  velocity  of  thirty  - 
!  two  and  one-sixth  feet,  which  is  therefore 
!  the  true  measure  of  the  force  of  gravity. 
I  The  rule   by  which  to  find  the  velocity  a 
falling  body  will    acquire   in   any  given 
time,  is. to  multiply  the  time  in  seconds 
by  32.166,  and  the  product  will  be  the 
velocity  acquired  in  feet  per  second. 

JACQUARD  MACHINE.  A  most  in- 
genious and  beautiful  piece  of  mechanism 
for  producing  the  pattern  in  figured 
weaving,  invented  by  M.  Jacquard,  of 
Lyons,  France,  and  .since  improved  by 
some  of  the  most  scientific  weavers  of 
Europe  and  America.     The    pattern    is 


ADDENDA. 


691 


produced  by  a  series  of  perforated  cards 
or  pasteboard  strips,  working  against 
parallel  rows  of  needles,  placed  in  a  hori- 
zontal position ;  these  needles  having 
eyes  in  them,  through  which  pass  the 
wires  or  cards  from  which  the  headles  are 
suspended.  The  longitudinal  motion  of 
the  needles  acts  on  the  cords  or  wires,  and 
causes  them  to  be  caught  up  or  missed 
by  a  lifting  apparatus,  and  those  which 
are  lifted  raise  the  threads  of  the  warp 
which  are  in  connexion  with  them,  and 
open  the  shed  for  the  shuttle  to  pass. 
The  pattern  cards  govern  the  motion  of 
the  needles  in  the  following  manner.  They 
are  connected  together  so  as  to  form  an 
endless  chain,  and  hung  upon  what  is 
termed  a  cylinder,  which  has  an  axle 
hung  in  a  frame  in  a  horizontal  position, 
at  right  angles  to  the  needles.  The  cylin- 
der is  generally  square,  each  side  corres- 
ponding in  size  with  the  pattern  cards, 
and  is  perforated  with  a  number  of  holes 
corresponding  to  the  number  of  needles  ; 
into  these  holes,  on  the  side  opposite  the 
needles,  the  points  of  the  needles  are 
forced,  by  springs,  to  enter,  when  not 
prevented  by  the  pattern  cards.  Each 
pattern  card  is  perforated  with  but  a  cer- 
tain number  of  holes,  these  correspond- 
ing, however,  with  certain  of  the  holes  in 
the  cylinder.  The  cylinder  is  drawn 
away  from  the  needles  every  time  it  is  de- 
sired to  open  the  shed,  and  before  it  is 
returned  to  its  place,  is  turned  by  suita- 
ble mechanism,  so  as  to  present  the  next 
side  and  a  new  card  to  the  needles. 
Where  this  new  card  is  perforated,  the 
needles  pass  through  into  the  cylinder, 
but  where  it  is  uncut  the  needles  are  pre- 
vented entering  the  perforations  in  the 
cylinderj  and  are  pushed  back  by  the 
card  which  forces  back  their  springs.  All 
the  needles  which  enter  the  cylinder, 
bring  the  headle  cords  or  wires  which 
pass  through  them  into  such  a  position 
as  to  be  caught  by  the  lifters,  and  raised 
to  make  the  shed  ;  and  all  those  which 
are  not  allowed  to  enter,  bring  their  cords 
or  wires  into  such  a  position  as  to  be 
missed  by  the  lifters  and  not  raised.  By 
putting  the  requisite  number  of  cards  in 
the  chain,  and  perforating  each  properly, 
any  pattern  may  be  produced,  and  by 
working  all  the  cards  over  and  over  again, 
in  regular  succession,  the  pattern  is  form- 
ed upon  the  cloth,  and  repeated  any  num-  i 
ber  of  times. 

By  this  machine  the  patterns  in  car- 
pets, figured  silks,  and  all  kinds  of  goods 
may  be  produced.  It  is  applied  to  lace 
machines  as  well  as  looms.    It  is  difficult 


to  make  it  perfectly  intelligible  to  the 
general  reader,  without  more  elaborate 
drawings  than  it  is  possible  to  give  in  a 
work  of  this  description,  but  it  is  believed 
that  sufficient  has  been  said  to  give  an 
idea  of  the  main  principles  of  its  opera- 
tion. It  may  be  well  to  remark  that  it 
has  contributed  more  than  any  other  im- 
provement, to  lessening  the  labor  and  cost 
in  the  production  of  figured  goods. 

MANDREL.  The  main  spindle  or  axis 
of  a  turning  lathe,  which  carries  or  gives 
revolution  to  the  work.  The  same  term 
is  also  applied  to  the  main  spindle  or  axis 
in  other  machines.  In  smithery  it  is  a 
tool  of  straight  and  slightly  tapering  form 
lengthwise,  but  of  any  form  in  its  trans- 
verse section.  It  is  used  for  finishing  or 
smoothing  the  inside  of  a  hole,  and  is 
driven  entirely  or  only  partly  through,  as 
the  size  of  the  hole  may  require.  It  is 
also  used  to  give  the  proper  form  to  the 
interior  of  any  hollow  object  which  is 
forged,  being  placed  within  it  while  the 
outside  is  hammered. 

MORTAR.  A  hollow  vessel  of  wood, 
metal,  stone,  glass,  or  any  other  material, 
generally  of  the  form  of  an  inverted  bell, 
in  which  various  substances  are  pounded 
or  ground  by  what  is  termed  a  pestle, 
which  is  in  the  form  of  a  shaft  rounded 
at  the  end.  It  is  most  commonly  used 
by  druggists.  Rice  is  usually  hulled  and 
cleaned  in  a  mortar,  the  pestle  being  ope- 
rated by  machinery,  as  it  is  of  very  large 
size. 

In  gunnery,  it  is  a  short  cannon  of  large 
bore,  used  for  throwing  bombs,  and  other 
kinds  of  shells  ;  it  derives  its  name  from 
its  resemblance  to  the  vessel  of  the  same 
name. 

PLANE,  a  perfectly  flat  surface.  In 
mechanical  manipulation,  a  tool  or  instru- 
ment for  producing  a  straight  even  sur- 
face. It  consists  of  a  cutter,  which  is 
placed  in  an  oblique  position  in  a  wooden 
stock,  whose  under  surface  is  perfectly 
straight,  the  edge  of  the  cutter  protruding 
slightly  through  the  face  of  the  stock.  It 
is  principally  used  for  wood,  and  is  hiid 
flat  on  the  surface,  and  worked  backwards 
and  forwards  by  the  workman,  every  for- 
ward movement  taking  off  a  shaving. 

PLANING  MACHINE.  A  machine 
for  planing  either  wood  or  metal.  The 
wood  planing  machine  is,  on  account  of 
the  immense  consumption  of  timber,  one 
of  the  most  valuable  machines  in  use  in 
the  United  States,  as  almost  all  the  plank 
used  is  planed  by  it,  and  except  in  joiners' 
work,  it  may  be  said  to  have  almost  su- 
perseded   the    hand    plane.      The    first 


692 


ADDENDA. 


planing  machine  ever  used  was  the  inven- 
tion of  Jeremy  Bentham,  of  England, 
and  was  patented  in  that  country  towards 
the  close  of  the  last  century.  It  consisted 
of  planes  nearly  similar  to  the  hand  plane, 
driven  hack  and  forth  by  machinery,  the 
hoards  being  held  down  on  a  suitable  bed 
by  pressure.  The  next  machine  was  in- 
vented in  1801,  by  Joseph  Bramah,  of 
London,  the  celebrated  mechanician,  and 
inventor  of  the  hydrostatic  press  ;  in  this 
machine  the  cutters  are  attached  to  a  re- 
volving disc,  the  boards  being  laid  par- 
allel to  the  face  of  the  disc,  and  moved  by 
suitable  means  longitudinally,  during  the 
time  the  cutters  are  passing  across  their 
faces.  The  "  Bramah  disc,"  as  it  is  term- 
ed, is  in  common  use  in  this  country  at 
the  present  day,  and  for  some  kinds  of 
work  is  better  than  any  other  arrange- 
ment of  cutters. 

The  best  machine  for  general  purposes, 
particularly  for  planing  flooring  boards, 
is  known  as  the  Woodworth  machine. 
The  cutters  in  this  machine  are  arranged 
at  intervals  apart,  around  a  cylinder,  or 
in  cylindrical  form,  the  edges  being  par- 
allel* with  the  axis.  The  boards  are  car- 
ried past  the  revolving  cutters,  between 
rotating  pressure  rollers,  or  as  they  are 
termed  "  feed  rollers."  There  are  other 
revolving  cutters,  somewhat  resembling 
thick  circular  saws,  arranged  so  as  to  cut 
rebates  in  the  edges  of  the  boards,  and 
form  a  tongue  on  one  edge,  and  a  groove 
in  the  other,  at  the  same  time  as  the  face 
is  being  planed.  These  cutters  arc  how- 
ever used  for  the  same  purpose  in  other 
machines,  in  combination  with  different 
planing  cutters.  This  machine  is  the  in- 
vention of  William  Woodworth,  an  Ame- 
rican, and  it  was  patented  in  this  country 
in  1828.  The  patent  was  extended  at  its 
expiration,  for  an  additional  term  of  four- 
teen years,  and  it  is  said  to  have  yielded 
a  profit  to  the  assignees,  who  now  hold  it, 
of  three  hundred  thousand  dollars  a  year, 
for  the  last  four  or  five  years.  Some  idea 
of  its  value  may  be  formed  from  the 
above  statement,  which  is  made  on  good 
authority.  It  is  intended  at  the  next  ses- 
sion of  Congress  to  apply  for  a  further 
extension  of  the  Patent,  which  expires  in 
1856;  but  it  will  be  stronsrly  opposed,  as 
an  usurpation  of  public  right  without  a 
precedent.  There  arc  various  other  ma- 
chines differing  but  slightly  from  it,  and 
almost  as  good. 

The  planing  machine  for  metal,  consists 
of  an  iron  bed,  to  which  the  pieces  to  be 
planed  are  secured  by  clamps  or  dogs, 
$ud  which  receives  a  reciprocating  motion 


under  the  planing  tool,  which  is  secured 
in  an  adjustable  rest  attached  to  a  station- 
ary head.  The  tool  is  pointed^  and  as  the 
work  moves  under  it,  it  planes  off  a  nar- 
row shaving,  and  then  requires  moving 
transversely  to  the  direction  of  the  move- 
ment of  the  work,  to  plane  another  sha- 
ving. A  surface  is  thus  planed  in  a  series 
of  narrow  strips.  The  operation  is  some- 
what slow,  but  very  perfect,  and  is  adapt- 
able to  cast  or  wrought  iron,  and  even  to 
steel.  This  machine  is  one  of  the  most 
useful  employed  in  engineering  and  ma- 
chine making  establishments. 

PLANT.  The  fixtures  and  tools  ne- 
cessary to  carry  on  a  trade  or  manufac- 
ture. 

SPECIFIC  GRAVITY  of  a  body  is  the 
relation  of  its  weight,  compared  with  the 
weight  of  some  other  body  of  the  same 
magnitude.  A  body  immersed  in  a  fluid 
will  sink  if  its  specific  gravity  be  greater 
than  that  of  the  fluid  ;  but  if  it  be  less, 
the  body  will  rise  to  the  top,  and  will  be 
only  partly  uncovered.  If  the  specific 
gravity  of' the  body  and  fluid  are  equal, 
then  the  body  will  remain  at  rest  in  any 
part  of  the  fluid.  If  the  body  be  heavier 
than  the  fluid,  it  loses  as  much  of  its 
weight  when  immersed  as  is  equal  in 
weight  to  a  quantity  of  the  fluid  of  the 
same  bulk.  If  the  specific  gravity  of  the 
fluid  be  greater  than  that  of  the  body, 
then  the  quantity  of  the  fluid  displaced 
by  the  part  immersed  is  equal  in  weight 
to  the  weight  of  the  whole  body.  There- 
fore the  specific  gravity  of  the  fluid  is  to 
that  of  the  body  as  the  whole  magnitude 
of  the  body  is  to  the  part  immersed.  The 
specific  gravities  of  solids  are  as  their 
parts  immersed  in  the  same  fluid.  The 
specific  gravities  of  fluids  are  as  the 
weights  lost  by  the  same  immersed 
body. 

To  form  a  table  of  the  specific  gravities 
of  various  substances,  it  is  necessary  to 
select  one  as  the  standard  of  comparison  : 
in  practice,  pure  water  is  always  chosen 
as  the  starting-point  for  solids  and  liquids, 
and  pure  atmospheric  air  for  gasses,  the 
number  1  (1.000)  expressing  the  specific 
gravities.  The  formation  of  two  series 
is  considered  to  be  more  convenient  than 
the  comparison  of  all  bodies  by  one  stand- 
ard, on  account  of  the  complexity  of  the 
numbers  which  would  result. 

The  following  is  a  table  of  the  spec  fio 
gravities  of  a  number  of  substances  :  all 
those  solids  which  are  capable  of  absorb- 
ing moisture  are  assumed  to  be  dry. 


ADDENDA. 


693 


SOLIDS   AND   LIQUIDS 


Water, 

Platinum, 

Gold, 

Mercury, 

Lead, 

Silver, 

Copper, 

Brass, 

Steel, 

Iron,  rod, 

Iron,  cast, 

Tin, 

Zinc, 

Diamond, 

Slate, 

Marble,  white, 

Granite, 

Rock  Crystal, 

Window  Glass, 

Chalk, 

Clay, 

Common  Earth, 

Brick, 


1.000 

21.5 

19.5 

13.5 

11.45 

10.5 
8.96 
8.37 
7.8 
7.7 
7.2 
7.29 
7.03 
3.5 
2.75 
2.7 
2.65 
2.6 
2.52 
2.815 
2 

1.52 
to  2 
1.841 


Coal,  bituminous, 

Oak, 

Ash, 

Beech, 

Mahogany, 

Elm, 

Pine,  American  yellow 

Wax, 

Sulphuric  acid, 

Sea  water, 

Oil  of  Turpentine,    . 

Spirit  of  Wine,  (strong) 

Ether, 

GASES. 

Atmospheric  air, 

Carbonic  acid, 

Oxygen, 

Chlorine, 

Light  carburetted  gas 

Nitrogen, 

Carbonic  oxide, 

Tit  coal  gas,       .  . 

Hydrogen,    . 


1.269 

0.83 

0.76 

0.696 

0.56 

0.544 

0.46 

0.964 

1.84 

1.027 

0.865 

0.83 

0.72 


1.000 

1.524 

1.106 

2-40 

0.985 

0.972 

0.967 

0.558 

0.069 


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